CN107428001B

CN107428001B - Robot with arms with unequal link lengths

Info

Publication number: CN107428001B
Application number: CN201680020616.2A
Authority: CN
Inventors: M·霍塞克
Original assignee: Persimmon Technologies Corp
Current assignee: Persimmon Technologies Corp
Priority date: 2015-02-06
Filing date: 2016-02-08
Publication date: 2021-07-13
Anticipated expiration: 2036-02-08
Also published as: CN107428001A; CN117621011A; KR20220048053A; CN113601482A; KR102430044B1; KR20170138395A; KR20230080488A; KR102386346B1; JP2018505065A; KR102451144B1; KR20220139430A; JP2020192680A; KR20180001602A; JP7079604B2; CN113601482B; WO2016127160A1; JP2023072085A

Abstract

The device comprises at least one driver; a first robot arm having a first upper arm, a first forearm, and a first end effector. The first upper arm is connected to the at least one drive at a first axis of rotation. The second robot arm has a second upper arm, a second forearm, and a second end effector. The second upper arm is connected to the at least one drive at a second axis of rotation spaced from the first axis of rotation. The first and second robot arms are configured to position the end effector in a first retracted position for at least partially stacking substrates positioned on the end effector one on top of the other. The first and second robot arms are configured to extend the end effector from the first retracted position in a first direction along parallel first paths at least partially directly above one another.

Description

Robot with arms with unequal link lengths

Technical Field

The disclosed embodiments relate to robots having arms with unequal link lengths and in particular to robots having one or more arms with unequal link lengths, each arm supporting one or more substrates.

Background

Vacuum, atmospheric, and controlled environment processes for applications such as those associated with the manufacture of semiconductors, LEDs, solar energy, MEMS, or other devices utilize robotics and other forms of automation to transport substrates and carriers associated with substrates to and from storage, processing, or other locations. Such transport of substrates may be moving individual substrates, groups of substrates, with a single arm transporting one or more substrates or with multiple arms each transporting one or more substrates. Most of the manufacturing associated with semiconductor manufacturing, for example, is done in clean or vacuum environments where real estate and volume are at a premium. Furthermore, most automated shipments are made where minimization of the number of shipments results in a reduction in cycle time and an associated increase in throughput and utilization of the equipment. Accordingly, there is a need to provide a substrate transport automation that requires minimal footprint and workspace volume for a given range of transport applications and with a minimized number of transports.

Disclosure of Invention

The following summary is intended to be merely exemplary. This summary is not intended to limit the claims.

In accordance with one aspect of the exemplary embodiments, a transport apparatus has at least one drive; a first robot arm having a first upper arm, a first forearm, and a first end effector. The first upper arm is connected to the at least one drive at a first axis of rotation. The second robot arm has a second upper arm, a second forearm, and a second end effector. The second upper arm is connected to the at least one drive at a second axis of rotation spaced from the first axis of rotation. The first and second robot arms are configured to position the end effector in a first retracted position for at least partially stacking substrates positioned on the end effector one on top of the other. The first and second robot arms are configured to extend the end effector from the first retracted position in a first direction along parallel first paths at least partially directly above one another. The first and second robot arms are configured to extend the end effector in at least one second direction along a second path spaced from one another that is not one above the other. The first upper arm and the first forearm have different effective lengths. The second upper arm and the second forearm have different effective lengths.

In accordance with another aspect of the exemplary embodiments, there is provided a method comprising: providing a first robotic arm comprising a first upper arm, a first forearm, and a first end effector, wherein the first upper arm and the first forearm have different effective lengths; providing a second robot arm comprising a second upper arm, a second forearm, and a second end effector, wherein the second upper arm and the second forearm have different effective lengths; connecting the first upper arm to the at least one drive at a first axis of rotation; and connecting the second upper arm to the at least one drive at a second axis of rotation spaced from the first axis of rotation, wherein the first and second robot arms are configured to position the end effector in a first retracted position for at least partially stacking substrates positioned on the end effector one on top of the other, wherein the first and second robot arms are configured to extend the end effector in a first direction from the first retracted position along parallel first paths at least partially positioned directly above the other, and wherein the first and second robot arms are configured to extend the end effector in at least one second direction along second paths spaced from each other that are not positioned one above the other.

In accordance with another aspect of the exemplary embodiments, there is provided a method comprising: positioning respective first and second end effectors of first and second robot arms in first retracted positions for stacking substrates located on the end effectors at least partially one on top of the other, wherein the first robot arm comprises a first upper arm, a first forearm, and a first end effector, wherein the first upper arm is connected to at least one drive at a first axis of rotation, and wherein the second robot arm comprises a second upper arm, a second forearm, and a second end effector, wherein the second upper arm is connected to at least one drive at a second axis of rotation spaced from the first axis of rotation; moving the first and second robot arms to move the end effector from the first retracted position in a first direction along parallel first paths at least partially directly above one another; and moving the first and second robot arms to move the end effector to extend the end effector in at least one second direction along a second path spaced from one another that is not one above the other.

In accordance with another aspect of the exemplary embodiments, a conveyance apparatus has: a first robotic arm comprising a first upper arm, a first forearm, and a first end effector; a second robot arm comprising a second upper arm, a second forearm, and a second end effector; and a drive connected to the first and second robot arms, wherein the first upper arm is connected to the drive at a first axis of rotation, wherein the second upper arm is connected to the drive at a second axis of rotation spaced from the first axis of rotation, wherein the drive includes only three motors for rotating the first and second upper arms, wherein the first and second robot arms are configured to position the end effector in the first retracted position for at least partially stacking substrates positioned on the end effector one on top of the other, wherein the first and second robot arms are configured to extend the end effector from the first retracted position in a first direction along parallel first paths at least partially directly above one another, and wherein the first and second robot arms are configured to extend the end effector in at least one second direction along a second path spaced from one another that is not above one another.

In accordance with another aspect of the exemplary embodiments, a method includes: positioning respective first and second end effectors of first and second robot arms in first retracted positions for stacking substrates located on the end effectors at least partially one on top of the other, wherein the first robot arm comprises a first upper arm, a first forearm, and a first end effector, wherein the first upper arm is connected to a drive at a first axis of rotation, and wherein the second robot arm comprises a second upper arm, a second forearm, and a second end effector, wherein the second upper arm is connected to the drive at a second axis of rotation spaced from the first axis of rotation; moving the first and second robot arms to move the end effector from the first retracted position in a first direction along parallel first paths at least partially directly above one another; moving the first and second robot arms to move the end effector to extend the end effector in at least one second direction along a second path spaced from one another that is not one above the other; rotating the first and second robot arms together about a third axis of rotation spaced from the first and second axes of rotation, wherein movement in the first direction from the first retracted position, movement and rotation extending the end effector in at least one second direction utilizes only three motors of the drive.

In accordance with another aspect of the exemplary embodiments, a method includes: providing a first robotic arm comprising a first upper arm, a first forearm, and a first end effector; providing a second robot arm comprising a second upper arm, a second forearm, and a second end effector; connecting a first upper arm to the drive at a first axis of rotation; and connecting the second upper arm to the drive at a second axis of rotation spaced from the first axis of rotation, wherein the first and second robot arms are configured to position the end effector in a first retracted position for at least partially stacking substrates located on the end effector one on top of the other, wherein the first and second robot arms are configured to be rotated to extend the end effector from the first retracted position in a first direction along parallel first paths at least partially one directly above the other, and wherein the first and second robot arms are configured to be rotated to extend the end effector in at least one second direction along second paths spaced from each other that are not one directly above the other, wherein the drive includes only three for rotating the first and second robot arms to extend the end effector and for rotating the first and second robot arms about a third axis of rotation spaced from the first and second axis of rotation A motor.

In accordance with another aspect of the exemplary embodiments, an apparatus includes: a first robotic arm comprising a first upper arm, a first forearm, and a first end effector; a second robot arm comprising a second upper arm, a second forearm, and a second end effector; and a drive connected to the first and second robot arms, wherein the first upper arm is connected to the drive at a first axis of rotation, wherein the second upper arm is connected to the drive at a second axis of rotation spaced from the first axis of rotation, wherein the drive comprises five motors for rotating the first and second upper arms, wherein a first one of the motors is connected to the first and second robot arms to rotate the first and second arms about a third axis of rotation spaced from the first and second axis of rotation, wherein a second and third one of the motors is connected to the first robot arm to rotate the first upper arm and the first forearm, respectively, and wherein a fourth and fifth one of the motors is connected to the second robot arm to rotate the second forearm and the first robot arm, respectively, independently, wherein the first and second robot arms are configured to position the end effector in a first effector withdrawn position for use in positioning the end effector in a first effector withdrawn position for at least part of a substrate located thereon Stacked one on top of the other, wherein the first and second robot arms are configured to extend the end effector from the first retracted position in a first direction along parallel first paths that are at least partially directly above one another, and wherein the first and second robot arms are configured to extend the end effector in at least one second direction along spaced second paths that are not directly above one another.

In accordance with another aspect of the exemplary embodiments, a method includes: positioning respective first and second end effectors of first and second robot arms in first retracted positions for stacking substrates located on the end effectors at least partially one on top of the other, wherein the first robot arm comprises a first upper arm, a first forearm, and a first end effector, wherein the first upper arm is connected to a drive at a first axis of rotation, and wherein the second robot arm comprises a second upper arm, a second forearm, and a second end effector, wherein the second upper arm is connected to the drive at a second axis of rotation spaced from the first axis of rotation; moving the first and second robot arms to move the end effector from the first retracted position in a first direction along parallel first paths at least partially directly above one another; moving the first and second robot arms to move the end effector to extend the end effector in at least one second direction along a second path spaced from one another that is not one above the other; rotating the first and second robot arms together about a third axis of rotation spaced from the first and second axes of rotation, wherein movement in the first direction from the first retracted position, movement and rotation to extend the end effector in at least one second direction utilizes five motors of the drive, wherein a first of the motors is connected to the first and second robot arms to rotate the first and second arms about the third axis of rotation, wherein a second and third of the motors is connected to the first robot arm to rotate the first upper arm and the first forearm, respectively, and wherein a fourth and fifth of the robot arms are connected to the second robot arm to rotate the second upper arm and the second forearm, respectively, independently of the first robot arm.

In accordance with another aspect of the exemplary embodiments, a method includes: providing a first robotic arm comprising a first upper arm, a first forearm, and a first end effector; providing a second robot arm comprising a second upper arm, a second forearm, and a second end effector; connecting a first upper arm to the drive at a first axis of rotation; and connecting the second upper arm to the drive at a second axis of rotation spaced from the first axis of rotation, wherein the first and second robot arms are configured to position the end effector in a first retracted position for at least partially stacking substrates located on the end effector one on top of the other, wherein the first and second robot arms are configured to be rotated to extend the end effector from the first retracted position in a first direction along parallel first paths at least partially located one directly above the other, and wherein the first and second robot arms are configured to be rotated to extend the end effector in at least one second direction along second paths spaced from each other that are not located one above the other, wherein the drive includes five axes of rotation for rotating the first and second robot arms to extend the end effector and for rotating the first and second robot arms about a third axis of rotation spaced from the first and second axes of rotation A motor, wherein a first of the motors is connected to the first and second robot arms to rotate the first and second arms about a third axis of rotation, wherein a second and third of the motors are connected to the first robot arm to rotate the first upper arm and the first forearm, respectively, and wherein a fourth and fifth of the robot arms are connected to the second robot arm to rotate the second upper arm and the second forearm, respectively, independently of the first robot arm.

In accordance with another aspect of the exemplary embodiments, an apparatus includes: a first robotic arm comprising a first upper arm, a first forearm, and a first end effector; a second robot arm comprising a second upper arm, a second forearm, and a second end effector; and a drive connected to the first and second robot arms, wherein the first upper arm is connected to the drive at a first axis of rotation, wherein the second upper arm is connected to the drive at a second axis of rotation spaced from the first axis of rotation, wherein the drive comprises four motors for rotating the first and second upper arms, wherein a first one of the motors is connected to the first upper arm, wherein a second one of the motors is connected to the second upper arm, wherein a third one of the motors is connected to the first forearm, wherein a fourth one of the motors is connected to the second forearm, wherein the third and fourth motors are aligned on a common axis spaced from the first and second axes, wherein the first motor is aligned on the first axis and wherein the second motor is aligned on the second axis, wherein the first and second robot arms are configured to position the end effector in a first retracted position for at least partially stacking substrates located on the end effector one on top of the other, wherein the first and second robot arms are configured to extend the end effector from the first retracted position in a first direction along parallel first paths that are at least partially directly above one another, and wherein the first and second robot arms are configured to extend the end effector in at least one second direction along spaced second paths that are not directly above one another.

Drawings

The foregoing aspects and other features are explained in the following description, taken in connection with the accompanying drawings, wherein:

FIG. 1A is a top view of a transport apparatus;

FIG. 1B is a side view of the transport apparatus;

FIG. 2A is a top partial schematic view of the transport apparatus;

FIG. 2B is a side cross-sectional partial schematic view of the transport apparatus;

FIG. 3A is a top view of the transport apparatus;

FIG. 3B is a top view of the transport apparatus;

FIG. 3C is a top view of the transport apparatus;

FIG. 4 is a graphical depiction chart;

FIG. 5A is a top view of the transport apparatus;

FIG. 5B is a side view of the transport apparatus;

FIG. 6A is a top partial schematic view of the transport apparatus;

FIG. 6B is a side cross-sectional partial schematic view of the transport apparatus;

FIG. 7A is a top view of the transport apparatus;

FIG. 7B is a top view of the transport apparatus;

FIG. 7C is a top view of the transport apparatus;

FIG. 8 is a graphical rendering;

FIG. 9 is a side cross-sectional partial schematic view of the transport apparatus;

FIG. 10A is a top view of the transport apparatus;

FIG. 10B is a side view of the transport apparatus;

FIG. 11A is a top view of the transport apparatus;

FIG. 11B is a side view of the transport apparatus;

FIG. 12 is a side cross-sectional partial schematic view of the transport apparatus;

FIG. 13 is a side cross-sectional partial schematic view of the transport apparatus;

FIG. 14A is a top view of the transport apparatus;

FIG. 14B is a top view of the transport apparatus;

FIG. 14C is a top view of the transport apparatus;

FIG. 15A is a top view of the transport apparatus;

fig. 15B is a side view of the conveyance apparatus;

FIG. 16A is a top view of the transport apparatus;

fig. 16B is a side view of the transport apparatus;

fig. 17A is a top view of the conveyance apparatus;

fig. 17B is a top view of the conveyance apparatus;

FIG. 18 is a side cross-sectional partial schematic view of the transport apparatus;

FIG. 19 is a side cross-sectional partial schematic view of the transport apparatus;

FIG. 20A is a top view of the transport apparatus;

fig. 20B is a top view of the transport apparatus;

fig. 20C is a top view of the transport apparatus;

FIG. 21A is a top view of the transport apparatus;

fig. 21B is a side view of the conveyance apparatus;

FIG. 22A is a top view of the transport apparatus;

fig. 22B is a side view of the transport apparatus;

FIG. 23 is a side cross-sectional partial schematic view of the transport apparatus;

fig. 24A is a top view of the transport apparatus;

fig. 24B is a top view of the transport apparatus;

fig. 24C is a top view of the transport apparatus;

fig. 25A is a top view of the transport apparatus;

fig. 25B is a side view of the conveyance apparatus;

fig. 26A is a top view of the transport apparatus;

fig. 26B is a top view of the conveyance apparatus;

fig. 26C is a top view of the transport apparatus;

fig. 27A is a top view of the conveyance apparatus;

fig. 27B is a side view of the conveyance device;

FIG. 28A is a top view of the transport apparatus;

fig. 28B is a side view of the transport apparatus;

fig. 29A is a top view of the conveyance apparatus;

fig. 29B is a top view of the conveyance apparatus;

fig. 29C is a top view of the transport apparatus;

FIG. 30A is a top view of the transport apparatus;

FIG. 30B is a side view of the transport apparatus;

fig. 31A is a top view of the conveyance apparatus;

fig. 31B is a side view of the conveyance apparatus;

FIG. 32A is a top view of the transport apparatus;

fig. 32B is a top view of the transport apparatus;

FIG. 32C is a top view of the transport apparatus;

FIG. 32D is a top view of the transport apparatus;

FIG. 33A is a top view of the transport apparatus;

fig. 33B is a side view of the conveyance apparatus;

fig. 34A is a top view of the transport apparatus;

fig. 34B is a top view of the transport apparatus;

fig. 34C is a top view of the transport apparatus;

FIG. 35A is a top view of the transport apparatus;

FIG. 35B is a side view of the transport apparatus;

FIG. 36 is a top view of the transport apparatus;

fig. 37A is a top view of the conveyance device;

fig. 37B is a side view of the transport apparatus;

fig. 38A is a top view of the transport apparatus;

fig. 38B is a side view of the transport apparatus;

FIG. 39 is a top view of the transport apparatus;

FIG. 40A is a top view of the transport apparatus;

FIG. 40B is a side view of the transport apparatus;

FIG. 41 is a top view of the transport apparatus;

FIG. 42 is a top view of the transport apparatus;

fig. 43A is a top view of the conveyance apparatus;

fig. 43B is a side view of the conveyance apparatus;

FIG. 44 is a top view of the transport apparatus;

FIG. 45 is a top view of the transport apparatus;

FIG. 46A is a top view of the transport apparatus;

FIG. 46B is a side view of the transport apparatus;

fig. 47A is a top view of the conveyance apparatus;

fig. 47B is a side view of the conveyance apparatus;

FIG. 48 is a top view of the transport apparatus;

FIG. 49 is a top view of the transport apparatus;

fig. 50A is a top view of the transport apparatus;

FIG. 50B is a side view of the transport apparatus;

FIG. 51 is a top view of the transport apparatus;

FIG. 52A is a top view of the transport apparatus;

fig. 52B is a side view of the transport apparatus;

FIG. 53 is a top view of the transport apparatus;

fig. 54A is a top view of the transport apparatus;

fig. 54B is a side view of the transport apparatus;

fig. 55A is a top view of the transport apparatus;

fig. 55B is a top view of the transport apparatus;

FIG. 55C is a top view of the transport apparatus;

fig. 56A is a top view of the transport apparatus;

fig. 56B is a side view of the transport apparatus;

fig. 57A is a top view of the transport apparatus;

fig. 57B is a top view of the conveyance apparatus;

fig. 57C is a top view of the transport apparatus;

FIG. 58A is a top view of the transport apparatus;

FIG. 58B is a side view of the transport apparatus;

fig. 59A is a top view of the transport apparatus;

fig. 59B is a top view of the transport apparatus;

fig. 59C is a top view of the transport apparatus;

FIG. 60A is a top view of the transport apparatus;

fig. 60B is a side view of the transport apparatus;

fig. 61A is a top view of the conveyance apparatus;

fig. 61B is a top view of the conveyance apparatus;

fig. 61C is a top view of the conveyance apparatus;

FIG. 62 is a top view of the transport apparatus;

FIG. 63 is a diagram illustrating an exemplary pulley;

FIG. 64 is a top view of the transport apparatus

FIG. 65 is a top view of the transport apparatus;

fig. 66A is a top view of the transport apparatus;

FIG. 66B is an isometric view of the transport apparatus;

FIG. 66C is an end view of the transport apparatus;

FIG. 66D is a side view of the transport apparatus;

fig. 67A is a top view of the conveyance apparatus;

FIG. 67B is an isometric view of the transport apparatus;

FIG. 67C is an end view of the transport apparatus;

fig. 67D is a side view of the conveyance apparatus;

fig. 68A is a top view of the transport apparatus;

fig. 68B is a top view of the transport apparatus;

fig. 69A to 69F are top views of the transport apparatus;

fig. 70A to 70F are top views of the conveyance apparatus;

fig. 71A to 71E are plan views of the conveyance device;

fig. 72A to 72B are side views of the conveyance apparatus;

fig. 72C to 72D are top and side views of the transport apparatus;

fig. 73A to 73B are top and side views of the conveyance apparatus;

fig. 73C to 73D are top and side views of the conveyance apparatus;

fig. 74A is a top view of the transport apparatus;

fig. 74B is a top view of the transport apparatus;

fig. 75A to 75F are top views of the transport apparatus;

FIG. 76A is a top view of the transport apparatus;

FIG. 76B is a top view of the transport apparatus;

FIG. 76C is a top view of the transport apparatus;

FIG. 76D is a top view of the transport apparatus;

fig. 77A to 77B are top and side views of the conveyance apparatus;

fig. 77C to 77D are top and side views of the conveyance apparatus;

fig. 78A to 78B are top and side views of the conveyance apparatus;

FIG. 79A is a top view of the transport apparatus;

FIG. 79B is a top view of the transport apparatus;

FIG. 80A is a top view of the transport apparatus; and

fig. 80B is a top view of the conveyance apparatus.

Detailed Description

In addition to the embodiments disclosed below, the disclosed embodiments are capable of other embodiments and of being practiced or being carried out in various ways. Accordingly, it is to be understood that the disclosed embodiments are not limited in their application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings. If only one embodiment is described herein, the claims are not limited to that embodiment. Furthermore, the claims are not to be read restrictively unless there is clear and convincing evidence manifesting a certain exclusion, restriction, or disclaimer.

Referring now to fig. 1A and 1B, a top view and a side view, respectively, of a robot 10 having a drive 12 and an arm 14 are shown. The arm 14 is shown in a retracted position. The arm 14 has an upper or first link 16 that is rotatable about a central axis of rotation 18 of the drive 12. The arm 14 further has a forearm or second link 20 rotatable about an elbow axis of rotation 22. The arm 14 further has an end effector or third link 24 that is rotatable about a wrist rotation axis 26. The end effector 24 supports a base 28. As will be described, the arm 14 is configured to cooperate with the drive 12 such that the base 28 is carried along a radial path 30 (as seen in fig. 1A) that may be coincident with the central rotational axis 18 of the drive 12 or a path (e.g., paths 34, 36) that is parallel to a linear path 32 coincident with the central rotational axis 18 of the drive 12. In the illustrated embodiment, the forearm or second link 20 has a greater joint-to-joint length than the upper arm or first link 16. In the illustrated embodiment, the lateral offset 38 of the end effector or third link 24 corresponds to the difference in the joint-joint length of the forearm 20 and the upper arm 14. As will be described in greater detail below, the lateral offset 38 is maintained substantially constant during extension and retraction of the arm 14 such that the substrate 28 is moved along a linear path without rotating the substrate 28 or the end effector 24 relative to the linear path. This is accomplished with structure internal to arm 14, as will be described, without the use of additional controlled axes to control rotation of end effector 24 relative to forearm 20 at wrist 26. In one aspect with respect to the embodiment disclosed in fig. 1A, the center of mass of the third link or end effector 24 may be located at a wrist centerline or axis of rotation 26. Alternatively, the center of mass of the third link or end effector 24 may follow a path 40 that is offset 38 from the central rotational axis 18. In this manner, interference with the band constraining end effector 24 relative to

links

16, 18 may be minimized due to the torque applied as a function of mass deflection during extension and retraction of the arms. Here, the center of mass may be determined with or without a substrate, or may be in between. Alternatively, the center of mass of the third link or end effector 24 may be located at any suitable location. In the illustrated embodiment, the substrate transport apparatus 10 transports a substrate 28 with the movable arm assembly 14 coupled to the driver section 12 on the central rotational axis 18. The base support 24 is coupled to the arm assembly 14 on a wrist axis of rotation 26, at which wrist axis of rotation 26 the arm assembly 14 rotates about the central axis of rotation 18 during extension and retraction, as will be seen with respect to fig. 3A-3C. Wrist rotational axis 26 moves during extension and retraction along a wrist path 40 parallel to central rotational axis 18 and offset 38 or otherwise from a radial path, such as

paths

30, 34 or 36, relative to central rotational axis 18. The substrate support 24 similarly moves parallel to the radial path 30 without rotation during extension and retraction. As will be described in greater detail in other aspects of the disclosed embodiments, the principles and structures that constrain movement of an end effector in a substantially pure radial motion may be applied where the length of the forearm is shorter than the length of the upper arm. Further, the features may be applied where more than one substrate is processed by the end effector. Furthermore, the features may be applied where the second arm is used in connection with a drive that processes one or more additional substrates. Accordingly, all such variations are encompassed.

Referring also to fig. 2A and 2B, there are shown partial schematic top and side views, respectively, of the system 10 showing the internal arrangement of the individual links used to drive the arm 14 shown in fig. 1A and 1B. The drive 12 has first and

second motors

52, 54 with corresponding first and

second encoders

56, 58 coupled to a housing 60 and driving first and

second shafts

62, 64, respectively. Here the shaft 62 may be coupled to a pulley 66 and the shaft 64 may be coupled to an upper arm 64, where the

shafts

62, 64 may be concentric or otherwise arranged. In alternate aspects, any suitable driver may be provided. The housing 60 may be in communication with a chamber 68, wherein the bellows 70, the chamber 68, and an interior portion of the housing 60 isolate a vacuum environment 72 from an atmospheric environment 74. The housing 60 may slide as a carriage in the z-direction on a slide 76, wherein a lead screw or other suitable vertical or linear z-drive 78 may be provided to selectively move the housing 60 and the arm 14 coupled thereto in the z 80 direction. In the illustrated embodiment, the upper arm 16 is driven about the central axis of rotation 18 by a motor 54. Similarly, the forearm is driven by the motor 52 through a belt

drive having pulleys

66, 82 and belts 84, 86 (such as conventional circular pulleys and belts, etc.). In alternative aspects, any suitable structure may be provided to drive the forearm 20 relative to the upper arm 16. The ratio between

pulleys

66 and 82 may be 1:1, 2:1, or any suitable ratio. The third link 24 with the end effector may be constrained by a belt drive having a pulley 88 grounded with respect to the link 16, a pulley 90 grounded with respect to the end effector or third link 24, and

belts

92, 94 that constrain the pulley 88 and pulley 90. As will be described, the ratio between the

pulleys

88, 90 may not be constant in order for the third link 24 to track a radial path without rotation during extension and retraction of the arm 14. This may be achieved where the

pulleys

88, 90 may be one or more non-circular pulleys, such as two non-circular pulleys, or where one of the

pulleys

88, 90 may be circular and the other non-circular. Alternatively, any suitable coupling or linkage may be provided to constrain the path of the third link or end effector 24 as described. In the illustrated embodiment, the at least one non-circular pulley compensates for the effect of the unequal lengths of the upper arm 16 and forearm 20 such that the end effector 24 points radially 30 regardless of the position of the first two

links

16, 20. The embodiment will be described with respect to pulley 90 being non-circular and pulley 88 being circular. Alternatively, the pulley 88 may be non-circular and the pulley 90 circular. Alternatively, pulleys 88 and 92 may be non-circular or any suitable coupling may be provided to constrain the links of arm 14 as described above. By way of example, a non-circular pulley or sprocket is described in U.S. patent No. 4,865,577 entitled non-circular drive, entitled 9/12 1989, which is hereby incorporated by reference in its entirety. Alternatively, any suitable coupling may be provided to constrain the links of the arms 14 as described above, for example, any suitable variable ratio drive or coupling, linkage gears or sprockets, cams or otherwise, used alone or in combination with suitable linkages or other couplings. In the illustrated embodiment, an elbow pulley 88 is coupled to the upper arm 16 and is shown as round or circular, with a wrist pulley 90 coupled to the wrist or third link 24 shown as non-circular. The wrist pulley shape is non-circular and may be symmetrical about a line 96 perpendicular to the radial trajectory 30, which line 96 may also coincide with or be parallel to a line between the two

pulleys

88, 90 when the forearm 20 and upper arm 16 are aligned on top of each other with the wrist axis 26 closest to the shoulder axis 18, as seen for example in fig. 3B. The shape of the pulley 90 is such that the

belts

92, 94 remain taut as the arm 14 extends and retracts, establishing

tangent points

98, 100 on opposite sides of the pulley 90 having varying

radial distances

102, 104 from the wrist rotational axis 26. For example, in the orientation shown in fig. 3B, each of the tangent points 98, 100 of the two belts on the pulley is at an

equal radial distance

102, 104 from the wrist rotational axis 26. This will be further described with respect to fig. 4, which shows the various ratios. In order to rotate the arm 14, both drive

shafts

62, 64 of the robot need to move the same amount in the direction of rotation of the arm. In order for the end effector 24 to extend and retract radially along a linear path, the two

driver shafts

62, 64 need to move in a coordinated manner, e.g., in accordance with exemplary inverse kinematics equations presented later in this section. Here, the substrate transport apparatus 10 is adapted to transport the substrate 28. The forearm 20 is rotatably coupled to the upper arm 16 and is rotatable about an elbow axis 22 that is offset from the central axis 18 by the length of the upper arm link. An end effector 24 is rotatably coupled to forearm 20 and is rotatable about a wrist axis 26 offset from elbow axis 22 by the length of the forearm link. A wrist pulley 90 is fixed to the end effector 24 and is coupled to the elbow pulley 88 with

belts

92, 94. Here, the forearm link length is different than the upper arm link length, and the end effector is constrained relative to the upper arm by an elbow pulley, wrist pulley, and belt such that the base moves along a linear radial path 30 relative to the central axis 18. Here, the base support 24 is coupled to the upper arm 16 with a base support coupling 92 and is driven about the wrist rotation axis 26 by relative movement between the forearm 20 and the upper arm 16 about the elbow rotation axis 22. Fig. 3A, 3B and 3C illustrate extension movements of the robot of fig. 1 and 2. Fig. 3A shows a top view of the robot 10 with the arm 14 in the retracted position. Fig. 3B depicts the arm 14 partially extended with the forearm 20 aligned on top of the upper arm 16, illustrating that the lateral offset 38 of the end effector corresponds to the difference in the joint-joint length of the forearm 20 and the upper arm 16. Fig. 3C shows the arm 14 in the extended position but not fully extended.

Exemplary forward kinematics may be provided. In alternative aspects, any suitable forward kinematics may be provided to correspond to the alternative configurations. The position of the end effector as a function of the position of the motor may be determined using the following exemplary equation:

x₂＝l₁cosθ₁+l₂cosθ₂ (1.1)

y₂＝l₁sinθ₁+l₂sinθ₂ (1.2)

R₂＝sqrt(x₂ ²+y₂ ²) (1.3)

T₂＝atan2(y₂,x₂) (1.4)

α₃＝asin(d₃/R₂) Wherein d is₃＝l₂-l₁ (1.5)

α₁₂＝θ₁-θ₂ (1.6)

If α is₁₂<π:R＝sqrt(R₂ ²-d₃ ²)+l₃,T＝T₂+α₃Otherwise, R ═ sqrt (R)₂ ²-d₃ ²)+l₃,T ＝T₂-α₃+π (1.7)

Exemplary inverse kinematics may be provided. In alternative aspects, any suitable inverse kinematics may be provided to correspond to the alternative configurations. The position of the motor may be determined using the following exemplary equation to obtain a specified position of the end effector:

x₃＝R cos T (1.8)

y₃＝R sin T (1.9)

x₂＝x₃-l₃cos T+d₃sin T (1.10)

y₂＝y₃-l₃sin T-d₃cos T (1.11)

R₂＝sqrt(x₂ ²+y₂ ²) (1.12)

T₂＝atan2(y₂,x₂) (1.13)

α₁＝acos((R₂ ²+l₁ ²-l₂ ²)/(2R₂l₁)) (1.14)

α₂＝acos((R₂ ²-l₁ ²+l₂ ²)/(2R₂l₂)) (1.15)

if R is>l₃:θ₁＝T₂+α₁,θ₂＝T₂-α₂Otherwise theta₁＝T₂-α₁,θ₂＝T₂+α₂ (1.16)

The following nomenclature can be used in the kinematic equations:

d₃transverse offset of end effector (m)

l₁Joint-joint length (m) of first link

l₂Joint-joint length of second link (m)

l₃Wrist to end effector articulation of third link with end effector

Length (m) measured by examination point

R radial position (m) of end effector

R₂Radial coordinate of wrist joint (m)

T ═ angular position of end effector (rad)

T₂Angular coordinate of wrist joint (rad)

x₂X coordinate of wrist joint (m)

x₃X coordinate (m) of the end effector

y₂The y coordinate of the wrist joint (m)

y₃Y-coordinate (m) of the end effector

θ₁Angular position (rad) of a driver shaft coupled to a first link

θ₂The angular position (rad) of the driver shaft coupled to the second link.

Suitable drives, for example, tape drives that constrain the orientation of the third link 24 such that the end effector 24 points radially 30 regardless of the position of the first two

links

16, 20 of the arm 14, may be designed using the above exemplary kinematic equations.

Referring to FIG. 4, the drive ratio r of the tape drive constraining the orientation of the third link is shown₃₁122 as a function of the normalized extension of the arm measured from the center of the robot to the root of the end effector, i.e., (R-l)₃)/l₁. Transmission ratio r₃₁Defined as the angular velocity ω of the pulley attached to the third link₃₂Angular velocity ω about a pulley attached to a first link₁₂Both defined relative to the second link. The figure graphically representsDifferent l₂/l₁(from 0.5 to 1.0 in 0.1 increments, and from 1.0 to 2.0 in 0.2 increments) of the gear ratio r₃₁. The profile of the non-circular pulley can be calculated to obtain the transmission ratio r according to fig. 4₃₁Such as the profiles depicted in fig. 2A, 54A, and 54B.

In the disclosed embodiment, utilizing one or more non-circular pulleys or other suitable means to constrain the end effector motion, a longer reach may be obtained compared to an equivalent linkage arm having the same containment volume. In alternative aspects, the first link may be driven by a motor either directly or via any kind of coupling or transmission arrangement. Any suitable gear ratio may be used herein. Alternatively, the belt drive actuating the second link may be replaced with any other arrangement having equivalent functionality, such as a belt drive, cable drive, gear drive, linkage-based mechanism, or any combination of the above. Similarly, the belt drive constraining the third link may be replaced with any other suitable arrangement such as a belt drive, cable drive, non-circular gear, linkage-based mechanism, or any combination of the above, or the like. Here, the end effector may be, but need not be, radially directed. For example, the end effector may be positioned at any suitable offset relative to the third link and pointed in any suitable direction. Further, in alternative aspects, the third link may carry more than one end effector or base. Any suitable number of end effectors and/or material holders may be carried by the third link. Further, in alternative aspects, the joint-to-joint length of the forearm may be less than the joint-to-joint length of the upper arm, e.g., as seen in fig. 4 with₂/l₁<1 and as seen and described with respect to fig. 25-34 and 43-53.

Referring now to fig. 5A and 5B, top and side views, respectively, of a robot 150 incorporating some of the features of the robot 10 are shown. The robot 150 is shown with the drive 12 and the arm 152 is shown in a retracted position. The arm 152 has similar features as the arm 14 except as described herein. By way of example, the forearm or second link 158 has a greater joint-to-joint length than the upper arm or first link 154. Similarly, the lateral offset 168 of the end effector or third link 162 corresponds to the difference in the joint-joint length of the forearm 158 and the upper arm 154. Referring also to fig. 6A and 6B, an internally disposed driver 150 having a separate linkage for driving the arm is shown. In the illustrated embodiment, the upper arm 154 is driven by a motor via shaft 64 as described with respect to arm 14 of fig. 1 and 2. Similarly, the end effector or third link 162 is constrained relative to the upper arm 154 by a non-circular pulley arrangement as described with respect to the arm 14 of fig. 1 and 2. An exemplary difference between the arm 152 and the arm 14 can be seen, wherein the front arm 158 is coupled to the shaft 162 of the drive 12 and another motor via a belt arrangement having at least one non-circular pulley. Here, the coupling or belt arrangement may have features as described herein or as described with respect to the pulley drives 88, 90 of fig. 1 and 2. The coupling or belt arrangement has a non-circular pulley 202 coupled to the shaft 62 of the drive 12 and is rotatable with the shaft 62 about the axis 18. The belt arrangement of the arm 152 further has a circular pulley 204 coupled to the upper arm link 158 and rotatable about the elbow axis 156. The circular pulley 204 is coupled to the non-circular pulley 202 via

belts

206, 208, wherein the

belts

206, 208 may be held taut by virtue of the contour of the non-circular pulley 202. In alternate aspects, any combination of pulleys or other suitable transmission may be provided. The

pulleys

202 and 204 cooperate with the

belts

206, 208 such that rotation of the upper arm 154 relative to the pulley 202 (e.g., holding the pulley 202 stationary while rotating the upper arm 154) causes the wrist joint 160 to linearly extend and retract along a desired radial path 180 parallel to the end effector and offset 168 from the path 180. Here, the third link 162 with the end effector is constrained by a belt drive, for example with at least one non-circular pulley, as described with respect to the arm 14, such that the end effector points radially 180 regardless of the position of the first two

links

154, 158. Here, any suitable coupling may be provided to constrain the links of the arms 14 as described, for example, one or more suitable variable ratio drives or couplings, linkage gears or sprockets, cams or otherwise, used alone or in combination with suitable linkages or other couplings. In the illustrated embodiment, the elbow pulley 204 is coupled to the forearm 158 and is shown as round or circular, with the shoulder pulley 202 being coupled to the shaft 62 and shown as non-circular. The shaft pulley shape is non-circular and may be symmetrical about a line 218 perpendicular to the radial trajectory 180, which line 218 may also coincide or be parallel with the line between the two

pulleys

202, 204 when the front arm 158 and the upper arm 154 are aligned with each other with the wrist axis 160 closest to the shoulder axis 18, as seen, for example, in fig. 7B. The shape of the pulley 202 causes the

belts

206, 208 to remain taut as the arm 154 extends and retracts, establishing

tangent points

210, 212 having varying

radial distances

214, 216 from the shoulder rotational axis 18 on opposite sides of the pulley 202. For example, in the orientation shown in fig. 7B, each of the

tangent points

210, 212 of the two belts on the pulley is at an

equal radial distance

214, 216 from the shoulder rotational axis 18. This will be further described with respect to fig. 8, which shows the various ratios. In order to rotate the arm 152, both drive

shafts

62, 64 of the robot need to move the same amount in the direction of rotation of the arm. In order for the end effector 162 to extend and retract radially along a linear path, the two

driver shafts

62, 64 need to move in a coordinated manner, e.g., in accordance with exemplary inverse kinematics equations presented later in this section, e.g., the driver shaft coupled to the upper arm needs to move in accordance with the inverse kinematics equations presented below, while the other motor is held stationary. Fig. 7A, 7B, and 7C illustrate extension movements of the robot 150 of fig. 5 and 6. Fig. 7A shows a top view of the robot with the arm 152 in its retracted position. Fig. 7B depicts the arm partially extended with the forearm aligned on top of the upper arm, illustrating a lateral offset 168 of the end effector 162 corresponding to the joint-to-joint length difference of the forearm 158 and the upper arm 154. Fig. 7C shows the arm in the extended position but not fully extended.

d₁＝l₁sin(θ₁-θ₂) (2.1)

if (theta)₁-θ₂)<π/2:θ_2l＝θ₂-l₂asin((d₁+d₃)/l₂) Otherwise theta_2l＝θ₂+l₂asin((d₁+ d₃)/l₂)+π (2.2)

x₂＝l₁cosθ₁+l₂cosθ_2l (2.3)

y₂＝l₁sinθ₁+l₂sinθ_2l (2.4)

R₂＝sqrt(x₂ ²+y₂ ²) (2.5)

T₂＝atan2(y₂,x₂) (2.6)

If (theta)₁-θ₂)<π/2:R＝sqrt(R₂ ²-d₃ ²)+l₃,T＝θ₂Otherwise, R ═ sqrt (R)₂ ²-d₃ ²)+l₃, T＝θ₂(2.7)

x₃＝R cos T (2.8)

y₃＝R sin T (2.9)

x₂＝x₃-l₃cos T+d₃sin T (2.10)

y₂＝y₃-l₃sin T-d₃cos T (2.11)

R₂＝sqrt(x₂ ²+y₂ ²) (2.12)

T₂＝atan2(y₂,x₂) (2.13)

α₁＝acos((R₂ ²+l₁ ²-l₂ ²)/(2R₂l₁)) (2.14)

if R is>l₃:θ₁＝T₂+α₁,θ₂T, otherwise θ₁＝T₂-α₁,θ₂＝T (2.15)

The following nomenclature can be used in the kinematic equations:

d₃transverse offset of end effector (m)

l₁Joint-joint length (m) of first link

l₂Joint-joint length of second link (m)

l₃Wrist to end effector articulation of third link with end effector

Length (m) measured by examination point

R radial position (m) of end effector

R₂Radial coordinate of wrist joint (m)

T ═ angular position of end effector (rad)

T₂Angular coordinate of wrist joint (rad)

x₂X coordinate of wrist joint (m)

x₃X coordinate (m) of the end effector

y₂The y coordinate of the wrist joint (m)

y₃Y-coordinate (m) of the end effector

θ₁Angular position (rad) of a driver shaft coupled to a first link

θ₂The angular position (rad) of the driver shaft coupled to the second link.

The above kinematic equations may be used to design a belt drive that controls the second link 158 such that rotation of the upper arm 154 causes linear extension and retraction of the wrist joint 160 along a desired radial path 180 parallel to the end effector 162.

Referring now to FIG. 8, a drive second link is shownDrive ratio r of a belt drive of a lever ₂₀272 as a function of the normalized extension of the arm measured from the center of the robot to the root of the end effector, i.e., (R-l)₃)/l₁. Transmission ratio r₂₀Defined as the angular velocity ω of a pulley attached to the second link₂₁Angular velocity ω about a pulley attached to the second motor₀₁Both defined relative to the first link. The figures graphically represent the relationship between l and₂/l₁is a transmission ratio r₂₀。

The profile of the non-circular pulley of the belt drive for driving the second link is calculated to obtain the transmission ratio r according to fig. 8₂₀272. An example pulley profile is depicted in fig. 6A and as will be described with respect to fig. 55A and 55B.

Gear ratio r of the belt drive constraining the orientation of the third link 168₃₁May be the same as that depicted in fig. 4 for the embodiment of fig. 1 and 2. Transmission ratio r₃₁Defined as the angular velocity ω of the pulley attached to the third link₃₂Angular velocity ω about a pulley attached to a first link₁₂Both defined relative to the second link. The figures graphically represent the relationship between l and₂/l₁(from 0.5 to 1.0 in 0.1 increments, and from 1.0 to 2.0 in 0.2 increments) of the gear ratio r₃₁. The profile of the non-circular pulley of the belt drive for constraining the third link 162 can be calculated to obtain the transmission ratio r according to fig. 4₃₁. An example pulley profile is depicted in fig. 6A.

In the illustrated embodiment, where a non-circular pulley or other suitable mechanism is used to constrain the end effector as described, a longer reach may be obtained compared to an equivalent linkage arm having the same containment volume. As compared to the embodiment disclosed in fig. 1 and 2, one or more belt drives having non-circular pulleys may replace the conventional pulleys at the shoulder axis 18. In alternative aspects, the first link may be driven by a motor, either directly or via any kind of coupling or transmission arrangement, for example, any suitable transmission ratio may be used. SubstitutionAlternatively, the belt drive that actuates the second link and constrains the third link may be replaced with any other arrangement having equivalent functionality, such as a belt drive, cable drive, non-circular gear, linkage-based mechanism, or any combination thereof. Further, the third link may be constrained to maintain the end effector radial via a conventional two-stage belt arrangement that synchronizes the third link with a pulley driven by the second motor, as illustrated in fig. 9. Alternatively, the two-stage belt arrangement may be replaced with any other suitable arrangement, such as a belt drive, cable drive, gear drive, linkage-based mechanism, or any combination thereof. Additionally, the end effector may, but need not, be directed radially. For example, the end effector may be positioned at any suitable offset relative to the third link and pointed in any suitable direction. In alternative aspects, the third link may carry more than one end effector or base. Here, any suitable number of end effectors and/or material holders may be carried by the third link. Furthermore, the joint-to-joint length of the forearm may be less than the joint-to-joint length of the upper arm, e.g. as indicated by l in fig. 8₂/l₁<1 is represented by.

Referring now to fig. 9, an alternative robot 300 is shown in which a third link may be constrained to maintain the end effector radial via a conventional two-stage belt arrangement that synchronizes the third link with a pulley driven by a second motor. Robot 300 is shown having a drive 12 and an arm 302. The arm 302 may have an upper arm or first link 304 coupled to the shaft 64 and rotatable about the center or shoulder axis 18. The arm 302 has a forearm or second link 308 rotatably coupled to the upper arm 304 at an elbow axis 306. The

links

304, 308 may be of unequal lengths as previously described. A third link or end effector 312 is rotatably coupled to the second link or forearm 308 at a wrist axis 310, wherein the end effector 312 may transport the substrate 28 along a radial path without

rotation using links

304, 308 having unequal link lengths as previously described. In the illustrated embodiment, the shaft 62 is coupled to two pulleys 314, 316, wherein the pulleys 314 may be circular and wherein the pulleys 316 may be non-circular. Here, the circular pulley 314 constrains the third link 312 to maintain the end effector 312 radial via a conventional two-

step

318, 320 circular belt arrangement that synchronizes the third link 312 with the pulley driven by the shaft 314. The two-

stage belt arrangement

318, 320 has a pulley 314 coupled to an elbow pulley 324 by a belt 322, the elbow pulley 324 being coupled to an elbow pulley 326, wherein the elbow pulley 326 is coupled to a wrist pulley 328 via a belt 330. The front arm 308 may further have an elbow pulley 332, which may be circular and coupled to the shoulder pulley 316 via a belt 334, wherein the shoulder pulley may be non-circular and coupled to the pulley 314 and the shaft 62.

The disclosed embodiments may be further embodied with respect to a robot having a robot drive with additional axes, and wherein an arm coupled to the robot drive may have an independently operable additional end effector capable of carrying one or more substrates. By way of example, an arm or "dual arm" configuration may be provided having two independently operable arm linkages, wherein each independently operable arm may have an end effector adapted to support one, two, or any suitable number of substrates. Here and as will be described below, each independently operable arm may have first and second links with different link lengths, and wherein the end effector coupled to the links and the supported substrate operate and track as described above. Here, the substrate transport apparatus may transport the first and second substrates and have first and second independently movable arm assemblies coupled to the driver section on a common axis of rotation. The first and second substrate supports are coupled to the first and second arm assemblies on first and second wrist rotational axes, respectively. One or both of the first and second arm assemblies rotate about a common axis of rotation during extension and retraction. The first and second wrist axes of rotation move along first and second wrist paths parallel to and offset from a radial path relative to the common axis of rotation during extension and retraction. The first and second substrate supports move parallel to the radial path without rotation during extension and retraction. Variations on the disclosed embodiments having multiple and independently operable arms are provided below, wherein any suitable combination of features may be provided in alternative aspects.

Referring now to fig. 10A and 10B, top and side views, respectively, of a robot 350 having a dual-arm arrangement are shown. The robot 350 has an arm 352 with a common upper arm 354 and independently

operable forearms

356, 358 each having a

respective end effector

360, 362. In the illustrated embodiment, both linkages are shown in their retracted positions. The lateral offset of the end effector 366 corresponds to the difference in the joint-joint length of the forearm 354 and the

upper arms

356, 358. In the illustrated embodiment, the upper arms may be the same length and longer than the forearms. Further,

end effectors

360, 362 are positioned above

forearms

356, 358. Referring now to fig. 11A and 11B, top and side views, respectively, of a robot 375 having arms in an alternative configuration are shown. In the illustrated embodiment, the arm 377 may have features as described with respect to fig. 10A and 10B, with both linkages shown in their retracted positions. In this configuration, the third link of the upper linkage having the end effector 382 is suspended below the forearm 380 to reduce the vertical spacing between the two

end effectors

382, 384. Here, a similar effect may be obtained by lowering 368 the top end effector 360 of the configuration of fig. 10A and 10B. Referring now also to fig. 12 and 13, the internal arrangement of the

robots

350, 375 used to drive the individual links of the arms of fig. 10 and 11, respectively, is shown. In the illustrated embodiment, the drive 390 may have first, second, and

third drive motors

392, 394, 396, which may be motor stator arrangements driving

concentric shafts

398, 400, 402, respectively, and having

position encoders

404, 406, 408, respectively. The Z drive 410 may drive the motor in a vertical direction, wherein the motor may be partially or fully housed within a housing 412 and wherein a bellows 414 seals an interior volume of the housing 412 from a chamber 416 and wherein the interior volume and the interior of the chamber 416 may operate within an isolated environment such as a vacuum or otherwise. In the illustrated embodiment, the common upper arm 354 is driven by a motor 396. Each of the two

forearms

356, 358 pivot on a common axis 420 at the elbow of the upper arm 354 and are independently driven by

motors

394, 396, respectively, via belt drives 422, 424, respectively, which may have conventional pulleys. The third links with

end effectors

360, 362 are constrained by

belt drives

426, 428, respectively, each having at least one non-circular pulley that compensates for the effects of unequal lengths of the upper arm and forearm. Here, the tape drive in each of the linkages may be designed using the technical method described for fig. 1 and 2, and wherein the kinematic equations presented for fig. 1 and 2 may also be used for each of the two linkages of the two arms. In order to rotate the arm, all three

driver axes

398, 400, 402 of the robot need to be moved by the same amount in the direction of rotation of the arm. In order to extend and retract one of the end effectors radially along a linear path, the drive shaft of the common upper arm and the drive shaft coupled to the forearm associated with the active end effector need to move in a coordinated manner according to the inverse kinematics equations for fig. 1 and 2. At the same time, the drive shaft coupled to the other forearm needs to be rotated in synchronism with the drive shaft of the common upper arm in order to keep the inactive end effector withdrawn. Referring now also to fig. 14A, 14B and 14C, the arm of fig. 11A and 11B is shown with the upper and lower linkages extended. Here, the

non-moving linkages

356, 360 rotate, while the moving

linkages

358, 362 extend. By way of example, the

upper linkages

358, 362 rotate as the

lower linkages

356, 360 extend, and the

lower linkages

356, 360 rotate as the

upper linkages

358, 362 extend. In the disclosed embodiment of fig. 10 and 11, the setting and control is simplified, where the arm arrangement can be used on a coaxial drive without dynamic seals, while providing a longer reach than an equal link length arm with the same containment volume. Here, no bridge is used to support either of the end effectors. In the illustrated embodiment, the inactive arm rotates when the active arm is extended. One of the wrists travels over the lower end effector (closer to the wafer than in an equal link arrangement).

Referring now to fig. 15A and 15B, top and side views, respectively, of a robot 450 having a dual arm arrangement are shown. The robot 450 has an arm 452 with a common upper arm 454 and independently

operable forearms

456, 458 each with a

respective end effector

460, 462. In the illustrated embodiment, both linkages are shown in their retracted positions. The lateral offset of the end effector 466 corresponds to the difference in the joint-joint length of the forearm 454 and the

upper arms

456, 458. In the illustrated embodiment, the upper arms may be the same length and longer than the forearms. Further,

end effectors

460, 462 are positioned above

forearms

456, 458. Referring also to fig. 16A and 16B, top and side views of a robot 475 having arms in an alternative configuration are shown. Again, both linkages are shown in their retracted positions. In this configuration, the third link and left linkage end effector 482 is suspended below the forearm 480 to reduce the vertical spacing between the two

end effectors

482, 484. A similar effect can be obtained by lowering the top end effector of the configuration of fig. 15A and 15B. Alternatively, a bridge may be used to support one of the end effectors. The combined upper arm link 454 may be a single piece as depicted in fig. 15 and 16, or it may be formed of two or

more sections

470, 472 as shown in the example of fig. 17A and 17B. Here, a two-section design may be provided that is lighter and uses less material, where the left 472 and right 470 sections may be identical components. Here, the two-piece design may also provide for adjustment of the angular offset between the left and right sections, which may be convenient when it is desired to support different retracted positions. Referring also to fig. 18 and 19, the internal arrangement of the individual links used to drive the arms of fig. 15 and 16, respectively, is shown. The combined upper arm 554 is shown as being driven by one motor having a shaft 402. Each of the two

front arms

456, 458 are independently driven by a motor via

shafts

400, 398 via belt drives 490, 492 each having a conventional pulley. Here, the

links

456, 458 rotate on

separate axes

494, 496, respectively. The third links with

end effectors

460, 462 are constrained by

belt drives

498, 500, respectively, each having at least one non-circular pulley that compensates for the effect of the unequal lengths of the upper arm and forearm. Here, the tape drives 498, 500 in each of the

linkages

456, 460 and 458, 462 are designed using the technical methods described with respect to fig. 1 and 2. The kinematic equations presented here for fig. 1 and 2 can also be used for each of the two-

arm linkages

456, 460 and 458, 462. In order to rotate the arm 452, all three

driver axes

398, 400, 402 of the robot need to be moved by the same amount in the direction of rotation of the arm. In order for one of the end effectors to extend and retract radially along a linear path, the drive shaft of the common upper arm and the drive shaft coupled to the forearm associated with the active end effector need to move in a coordinated manner according to the inverse kinematics equations presented with respect to fig. 1 and 2. At the same time, the drive shaft coupled to the other forearm needs to be rotated in synchronism with the drive shaft of the common upper arm in order to keep the inactive end effector withdrawn. Referring also to fig. 20A, 20B and 20C, the arms of fig. 16A and 16B are shown with the left 458, 462 and right 456, 460 linkages extended. Note that the

inactive linkages

456, 460 rotate when the

active linkages

458, 462 are extended. Here,

right linkages

456, 460 rotate when left

linkages

458, 462 are extended, and left

linkages

458, 462 rotate when

right linkages

456, 460 are extended. The illustrated embodiment takes advantage of the benefits of a solid link design that is easy to set and control and a coaxial drive, for example, without dynamic seals, while providing a longer reach than an equivalent link arm with the same containment volume. Here, no bridge is used to support either of the end effectors. Here, the inactive arm rotates when the active arm is extended. One of the wrist joints travels over the lower end effector closer to the wafer than in an equal link arrangement. This can be avoided by using a bridge (not shown) to support the top end effector. In this case, the unsupported length of the bridge may be longer than an equal link arm design. Furthermore, the retraction angle may be more difficult to change than a configuration with a common elbow joint, as seen for example in fig. 10 and 11, and separate arms, as seen for example in fig. 21 and 22.

Referring now to fig. 21A and 21B, top and side views of a robot 520 with independent

dual arms

522, 524 are shown, respectively. In the illustrated embodiment, both

linkages

522, 524 are shown in their retracted positions. The arm 522 has an independently operable upper arm 526, forearm 528 and a third link with an end effector 530. The arm 524 has an independently operable upper arm 532, a forearm 534, and a third link with an end effector 536. In the illustrated embodiment, the

forearms

528, 534 are shown longer than the

upper arms

526, 532, with the

end effectors

530, 536 positioned above the

forearms

528, 534, respectively. Referring also to fig. 22A and 22B, top and side views of robot 550 are shown, robot 550 having similar features to those of robot 520, with the arms in an alternative configuration and both linkages shown in their retracted positions. In this configuration, the third link and left linkage end effector 552 is suspended below the forearm 554 to reduce the vertical spacing between the two end effectors. A similar effect can be obtained by lowering the top end effector of the configuration of fig. 21. Alternatively, a bridge may be used to support one of the end effectors. In fig. 21 and 22, the right upper arm 532 is located below the left upper arm 526. Optionally, the left upper arm may be located above the right upper arm, for example, one of the linkages may be nested within the other. Referring also to fig. 23, the internal arrangement of the individual links used to drive the arms of fig. 21A and 21B is shown. Here, for the sake of clarity of the drawing, to avoid overlapping of the parts, the elevation (elevation) of the link is adjusted. Each of the two

upper arms

526, 532 is independently driven by a motor via

shafts

398, 402, respectively. The

front arms

528, 534 are coupled to a third motor via a shaft 400 by means of

belt arrangements

570, 572 each having at least one non-circular pulley. The

third links

530, 536 with end effectors are constrained by

belt drives

574, 576 each having at least one non-circular pulley. The belt drive is designed such that rotation of one of the

upper arms

526, 532 causes the

corresponding linkage

528, 530 and 534, 536 to extend and retract along a straight line, respectively, while the other linkage remains stationary. The tape drive of each of the linkages may be designed using the technical approach described with respect to fig. 5 and 6, where the kinematic equations presented for fig. 5 and 6 may also be used for each of the two linkages of the two arms. In order to rotate the arm, all three

driver axes

398, 400, 402 of the robot need to be moved by the same amount in the direction of rotation of the arm. In order for one of the end effectors to extend and retract radially along a linear path, the drive shaft of the upper arm associated with the active end effector needs to be rotated according to the inverse kinematics equations for fig. 5 and 6 and the other two drive shafts need to be held stationary. Referring also to fig. 24A, 24B and 24C, the arm of fig. 22 is shown with the left 522 and right 524 linkages extended. Note that inactive linkage 524 remains stationary while active linkage 522 is extended. That is, the left linkage 522 does not move when the right linkage 524 is extended, and the right linkage 524 does not move when the left linkage 522 is extended. The illustrated embodiment provides a longer reach than an equivalent link arm design with the same containment volume. Here, no bridge is used to support either of the end effectors and the inactive linkages remain stationary while the resulting linkage is extended, potentially resulting in higher throughput as the active linkages can be extended or retracted faster without load. The illustrated embodiment may be more complex than that shown in fig. 15-16, replacing the conventional pulley with more than two belt drives having non-circular pulleys. One of the wrist joints travels over the lower end effector as seen in fig. 24. This can be avoided by using a bridge (not shown) to support the top end effector. In this case, the unsupported length of the bridge is longer compared to an equal link arm design.

Referring now to fig. 25A and 25B, top and side views, respectively, of a robot 600 having an arm 602 are shown. In the illustrated embodiment, both linkages are shown in their retracted positions. The lateral offset of the end effector 604 corresponds to the difference in the joint-to-joint length of the upper arm 606 and the

forearms

608, 612, where in this embodiment the

forearms

608, 612 are shorter than the common upper arm 606. The internal arrangement of the individual links used to drive the arms may be similar to that of figures 10 to 13, for example as in figure 13, however the forearms in this example are shorter than the common upper arm. Here, the common upper arm is driven by one motor. Each of the two forearms is independently driven by one motor via a belt drive with a conventional pulley. The

third links

614, 616 with the end effectors are constrained by belt drives each having at least one non-circular pulley (to compensate for the effect of unequal lengths of the upper arm and forearm). The tape drives in each of the linkages may be designed using the technical methods described with respect to fig. 1 and 2. The kinematic equations presented for fig. 1 and 2 can also be used for each of the two linkages of the two arms. Referring also to fig. 26A, 26B and 26C, the arm of fig. 25A and 25B is shown with the

upper linkages

612, 616 extended. The lateral offset 604 of the end effector corresponds to the difference in the joint-to-joint length of the upper arm and forearm, and the wrist joint travels along a line that is offset from the trajectory of the center of the wafer by this difference. Note that the

inactive linkages

608, 614 rotate when the

active linkages

612, 616 are extended. For example, the upper linkage rotates when the lower linkage is extended, and the lower linkage rotates when the upper linkage is extended. Here, fig. 26A depicts the arm with both linkages in the retracted position. Fig. 26B shows the

upper linkages

612, 616 partially extended at a position where the wrist of the upper linkage is closest to the wafer carried by the lower linkage. It was observed that the wrist of the upper linkage did not travel over the wafer (however, it moved in a plane above the wafer). Fig. 26C shows a further extension of the

upper linkages

612, 616. The illustrated embodiments may provide ease of setting and control, and may be used on coaxial or triaxial drives, or other suitable drives, that do not have dynamic seals. Here, the bridge may not be used to support any of the end effectors. The wrist of the upper linkage does not travel over the wafer on the lower end effector, which is the case for an equal link design (however, it moves in a plane above the wafer on the lower end effector). Here, the inactive arm rotates when the active arm is extended. The elbow joint may be more complex, it may translate a larger swing radius or a shorter reach. Here, the arms may be taller than shown in fig. 30 and 31 and 33 due to the overlapping

front arms

608, 612.

Referring now to fig. 27A and 27B, top and side views, respectively, of a robot 630 having an arm 632 is shown. The arm 630 may have similar features as disclosed with respect to fig. 15-19, except that the

forearms

636, 640 are shown as having a shorter link length than the upper arm 636. Both linkages are shown in their retracted positions. The lateral offset 634 of the

end effectors

642, 646 corresponds to the difference in the joint-to-joint length of the upper arm 636 and the

forearms

638, 640. The combined upper arm link 636 may be a single piece as depicted in fig. 27A and 27B, or it may be formed of two or more sections 636', 636 "as shown in the example of fig. 28A and 27B. The two-section design may be lighter, have less material, and where the left 636' and right 636 "sections may be the same part. Provision may be made to allow adjustment of the angular offset between the left 636' and right 636 "sections, for example, in the event that different retraction positions need to be supported. The internal arrangement of the separate links used to drive the arm 632 may be similar to that of fig. 15-19, for example, as seen in fig. 19. The common upper arm 636 is driven by one motor. Each of the two

front arms

638, 640 is independently driven by one motor via a belt drive having a conventional pulley. The third links with

end effectors

642, 646 may be constrained by belt drives each having at least one non-circular pulley (to compensate for the effect of the unequal lengths of the upper arm 636 and forearms 638, 640). The tape drives in each of the linkages may be designed using the technical methods described with respect to fig. 1 and 2. The kinematic equations presented for fig. 1 and 2 can also be used for each of the two linkages of the two arms. Referring also to fig. 29A, 29B and 29C, the arms of fig. 27A and 27B are shown with the right and left

linkages

640, 646 extended. The end effector lateral offset 634 corresponds to the difference in the joint-to-joint length of the upper arm and forearm, and the wrist joint travels along a line offset from the trajectory of the center of the wafer by this difference. Here, the

inactive linkages

638, 642 rotate as the

active linkages

640, 646 extend. For example, the upper linkage rotates when the lower linkage is extended, and the lower linkage rotates when the upper linkage is extended. In fig. 29A, 29B, and 29C, fig. 29A depicts the arm with both linkages in the retracted position. Fig. 29B shows the upper

right linkages

640, 646 partially extended in a position where the wrist joints of the upper

right linkages

640, 646 are closest to the wafers carried by the lower

left linkages

638, 642. Here, the wrist of the

upper right

640, 646 linkage does not travel over the wafer, however it moves in a plane above the wafer. Fig. 29C depicts a further extension of the upper

right linkages

640, 646. The illustrated embodiment takes advantage of the solid link design for ease of setting and control and the benefits of, for example, a coaxial drive without dynamic seals. No bridge is used to support either of the end effectors. The wrist of the upper linkage does not travel over the wafer on the lower end effector, which is the case for an equal link design, however it moves in a plane above the wafer on the lower end effector. The

inactive arms

638, 642 rotate when the

active arms

640, 646 are extended. The retraction angle may be more difficult to change than a configuration with a common elbow joint, as seen for example in fig. 25A and 25B, and separate arms, as seen for example in fig. 33A and 33B. Further, the arm is shown higher than in fig. 30 and 31 and fig. 33A and 33B because the front arm 640 is shown at a higher elevation than the front arm 638.

Referring now to fig. 30A and 30B, top and side views, respectively, of a robot 660 having an arm 662 are shown. Arm 662 may have features as described with respect to fig. 27-29, however a bridge is employed as will be described and has two forearms at the same elevation. Both linkages are shown in their retracted positions. The lateral offset 664 of the end effector corresponds to the difference in the joint-joint length of the upper arm 66 and the

forearms

668, 670. The combined upper arm link 666 may be a single piece as depicted in fig. 30A and 30B, or it may be formed of two or more sections 666', 666 "as shown in the example of fig. 31A and 31B. The internal arrangement of the individual links used to drive the arms may be the same as that shown for fig. 15-19, but with the

forearms

668, 670 being shorter than the upper arm 666. The common upper arm 666 is driven by one motor. Each of the two

front arms

668, 670 is independently driven by one motor via a belt drive having a conventional pulley. The third links with

end effectors

672, 674 are constrained by belt drives each having at least one non-circular pulley (to compensate for the effect of unequal lengths of the upper arm and forearm). The tape drives in each of the linkages may be designed using the technical methods described with respect to fig. 1 and 2. The kinematic equations presented for fig. 1 and 2 can also be used for each of the two linkages of the two arms. The third link and end effector 674 has a bridge 680 having an upper end effector portion 682, a side offset support portion 684 offset from the wrist axis between the link 670 and the link 674, and further having a lower support portion 686 coupling the wrist axis to the offset support portion 684. The bridge 680 allows the

forearms

668 and 670 to be packaged at the same level while providing clearance for the interleaved portions of the third link and end effector 672 (which may include a wafer) and the bridge 680, as can be seen below with respect to fig. 32. The bridge 680 further provides an arrangement in which any moving components (e.g., associated with the two wrist joints) are present below the wafer surface during transport. Referring also to fig. 32A, 32B, 32C, and 32D, top views of the robot arm of fig. 30A and 30B are shown with the

right linkages

670, 674 extended. The lateral offset 664 of the end effector corresponds to the difference in joint-to-joint length of the upper arm 666 and forearm 670, and the wrist joint 690 travels along a line that is offset from the trajectory of the center of the wafer 692 by the difference. Note that the inactive linkages 668, 673 rotate as the

active linkages

670, 674 extend. For example, the upper linkage rotates when the lower linkage is extended, and the lower linkage rotates when the upper linkage is extended. In fig. 32A, 32B, 32C, and 32D, fig. 32A depicts the arm with both linkages in the retracted position. Fig. 32B shows the

right linkages

670, 674 partially extended at a position corresponding to the worst case gap (or near worst case gap) between the bridge 680 of the

right linkages

670, 674 and the end effector 672 of the

left linkages

668, 672. Fig. 32C shows the

right linkages

670, 674 partially extended in a position when the forearm 670 is aligned with the upper arm 666. The lateral offset of the end effector corresponds to the difference in the joint-joint length of the upper arm and forearm. The wrist 690 axis travels along a straight line that is offset from the difference with respect to the trajectory of the center of the wafer 692. Fig. 32D depicts further extension of the

right linkages

670, 674. The illustrated embodiment combines the benefits of side-by-side dual scara arrangements (e.g., elongated profiles), resulting in shallow chambers with small volumes, solid link designs, and coaxial drives. The bridge 680 on the

right linkages

670, 674 is much lower and its unsupported length between the upright member 684 and wrist 690 is shorter than in prior art coaxial double scara arms, and all joints are underneath the end effector. Here, the inactive arms 688, 672 rotate as the

active arms

670, 674 extend. As will be described below, in other aspects of the disclosed embodiments, and not exhibiting this behavior, the arm may be provided with a different belt drive as disclosed herein having a non-circular pulley in place of a conventional pulley. Alternatively, the bridge supporting the top end effector may be eliminated by utilizing arrangements similar to those described above with respect to fig. 25A and 25B and fig. 27 and 28.

Referring now to fig. 33A and 33B, a top view and a side view, respectively, of a robot 700 having an arm 702 are shown. The arm 702 may have similar features to those of the arm shown in fig. 21-23, but with the forearm being shorter in length than the upper arm and employing a bridge as described by way of example with respect to the bridge 680 and with the forearm being at the same elevation. Both linkages are shown in their retracted positions. In fig. 33A and 33B, the right upper arm 708 is located above the left upper arm 706. Optionally, the left upper arm 706 may be positioned above the right upper arm 708. Similarly, the third link and end effector 716 of the

right linkages

712, 716 features a bridge that extends across the third link and end effector 714 of the

left linkages

710, 714. Alternatively, the third link and end effector 714 of the

left linkages

710, 714 may feature a bridge extendable across the third link and end effector 716 of the

right linkages

712, 716. The internal arrangement of the individual links used to drive the arms may be similar to the embodiment shown in figures 21 to 23. Each of the two

upper arms

706, 708 is independently driven by one motor. The

front arms

710, 712 are coupled to a third motor via a belt arrangement each having at least one non-circular pulley. The

third links

714, 716 with end effectors are constrained by belt drives each having at least one non-circular pulley. The belt drive is designed such that rotation of one of the

upper arms

706, 708 causes the corresponding linkage to extend and retract along a straight line while the other linkage remains stationary. The tape drives in each of the linkages are designed using the technical methods described for the embodiments shown in fig. 5 and 6. The kinematic equations presented for the embodiments shown in fig. 5 and 6 may also be used for each of the two linkages of the two arms. Referring also to fig. 34A, 34B, and 34C, the arms of fig. 33A and 33B are shown with the

right linkages

708, 712, 716 extended. Here, the

inactive linkages

706, 710, 714 remain stationary while the

active linkages

712, 716 are extended. That is, the left linkage does not move when the right linkage is extended, and the right linkage does not move when the left linkage is extended. The illustrated embodiment combines the benefits of a side-by-side dual scara arrangement (e.g., elongated profile), resulting in shallow chambers and coaxial drives with small volumes. The bridge on the right linkage is much lower and its unsupported length is shorter than in the existing coaxial double scara arm, and all joints are under the end effector. Inactive linkages remain stationary while the active linkages are extended, potentially resulting in higher throughput because the active linkages can be extended or retracted faster without load. Alternatively, the bridge supporting the top end effector may be eliminated by utilizing arrangements similar to those described with respect to fig. 25, 27, and 28.

Referring now to fig. 35A and 35B, top and side views of a robot having an arm 732 are shown, with both linkages shown in their retracted positions. Each linkage has a dual

holder end effector

740, 742, each supporting two bases offset from each other, for a total of 4 bases. The internal arrangement of the separate links used to drive the arm 732 may be the same as in fig. 10 and 11, e.g., fig. 13. The common upper arm 734 is driven by one motor. Each of the two front arms 73736, 738 is independently driven by one motor through a belt drive having a conventional pulley. The third links with the

end effectors

740, 742 are constrained by belt drives each having at least one non-circular pulley (to compensate for the effect of unequal lengths of the upper arm and forearm). The illustrated embodiment has a forearm that is longer than the upper arm. Alternatively, they may be shorter. The tape drives in each of the linkages are designed using the technical methods described with respect to fig. 1 and 2. The kinematic equations presented for fig. 1 and 2 can also be used for each of the two linkages of the two arms. Referring also to fig. 36, the arm of fig. 35A and 35B is shown with one

linkage

738, 742 extended. Note that the

inactive linkages

736, 740 rotate when the

active linkages

738, 742 are extended. For example, the upper linkage rotates when the lower linkage is extended, and the lower linkage rotates when the upper linkage is extended. In contrast to fig. 37 and 38, the end effector need not be shaped to avoid interference with the opposite elbow.

Referring now to fig. 37A and 37B, top and side views, respectively, of a robot having an arm 750 is shown. Both linkages are shown in their retracted positions, with each linkage having a dual

holder end effector

758, 760. The combined upper arm link 752 may be a single piece as depicted in fig. 37A and 37B, or it may be formed of two or more sections 752', 752 "as shown in the example of fig. 38A and 38B. The internal arrangement of the individual links used to drive the arms may be the same as in fig. 15-19, e.g. fig. 19. The combined upper arm 752 is driven by a motor. Each of the two

front arms

754, 756 are independently driven by one motor via a belt drive having a conventional pulley. The

third links

758, 760 with end effectors are constrained by belt drives each having at least one non-circular pulley (to compensate for the effect of unequal lengths of the upper arm and forearm). The illustrated embodiment has a forearm that is longer than the upper arm. Alternatively, they may be shorter. The tape drives in each of the linkages are designed using the technical methods described with respect to fig. 1 and 2. The kinematic equations presented for fig. 1 and 2 can also be used for each of the two linkages of the two arms. In order to rotate the arm, all three actuator axes of the robot need to move the same amount in the direction of rotation of the arm. In order to extend and retract one of the end effector assemblies radially along a linear path, the drive shafts of the common upper arm and the drive shafts coupled to the forearms associated with the movable linkages need to move in a coordinated manner in accordance with the inverse kinematics equations for fig. 1 and 2. At the same time, the drive shaft coupled to the other forearm needs to rotate in synchronism with the drive shaft of the common upper arm in order to keep the inactive linkage withdrawn. Referring also to fig. 39, the arm of fig. 37A and 37B is shown with one

linkage

756, 760 extended. Here, the

inactive linkages

754, 758 rotate as the active linkages extend. For example, the right linkage rotates when the left linkage is extended, and the left linkage rotates when the right linkage is extended. The embodiment shown does not have a bridge. The upper wrist travels over one of the wafers on the lower end effector. Here, the arms and end effectors need to be designed such that the top elbow is spaced apart from the lower end effector.

Referring now to fig. 40A and 40B, top and side views, respectively, of a robot 750 having an arm 752 are shown. Both linkages are shown in their retracted positions, with each linkage having dual

holder end effectors

792, 794. The internal arrangement of the individual links used to drive the arms may be the same as in figures 21 to 23. Each of the two

upper arms

784, 786 is independently driven by one motor. The

forearms

788, 790 are coupled to a third motor via belt arrangements each having at least one non-circular pulley. The third link with

end effectors

792, 794 is constrained by belt drives each having at least one non-circular pulley. The belt drive is designed such that rotation of one of the upper arms causes the corresponding linkage to extend and retract along a straight line while the other linkage remains stationary. The illustrated embodiment has a forearm that is longer than the upper arm. Alternatively, they may be shorter. The tape drives in each of the linkages are designed using the technical methods described with respect to fig. 5 and 6. The kinematic equations presented for fig. 5 and 6 can also be used for each of the two linkages of the two arms. In order to rotate the arm, all three actuator axes of the robot need to move the same amount in the direction of rotation of the arm. In order for one of the end effector assemblies to extend and retract radially along a linear path, the drive shaft of the upper arm associated with the movable linkage needs to be rotated according to the inverse kinematics equations for fig. 5 and 6, and the other two drive shafts need to be held stationary. Referring also to fig. 41, the arm of fig. 40A and 40B is shown with one

linkage

784, 788, 794 extended. Note that

inactive linkages

786, 790, 792 may remain stationary while

active linkages

794, 788, 794 are extended. That is, the left linkage does not move when the right linkage is extended, and the right linkage does not move when the left linkage is extended. Alternatively, the left and right linkages may be independently radially moved simultaneously, for example as seen in fig. 42, with the right linkage independently slightly extended as compared to fig. 41. The motion of the elbow of the upper linkage may be limited due to potential interference with the wafer on the lower end effector, which may limit the reach of the robot, as illustrated in fig. 41. This limitation can be mitigated by slightly extending the lower linkage to provide additional clearance and achieve full reach as shown in fig. 42. The embodiment shown does not have a bridge. The wrist of the upper linkage may travel over the wafer on the lower end effector.

Referring now to fig. 43A and 43B, a top view and a side view, respectively, of a robot 810 having an arm 812 is shown. Both linkages are shown in their retracted positions, with each linkage having a dual

holder end effector

820, 822. The internal arrangement of the individual links used to drive the arms may be the same as in figures 10 to 13. The common upper arm 814 is driven by one motor. Each of the two

forearms

816, 818 is independently driven by one motor via a belt drive with a conventional pulley. The third link with

end effectors

820, 822 is constrained by belt drives each having at least one non-circular pulley (to compensate for the effect of unequal lengths of the upper arm and forearm). In the illustrated embodiment, the forearm is shorter than the upper arm; alternatively they may be longer. The tape drives in each of the linkages are designed using the technical methods described with respect to fig. 1 and 2. The kinematic equations presented for fig. 1 and 2 can also be used for each of the two linkages of the two arms. Referring also to fig. 44 and 45, the arm of fig. 43A and 43B is shown with the

upper linkages

818, 822 extended. Note that the

inactive linkages

816, 820 rotate as the

active linkages

818, 822 extend. For example, the upper linkage rotates when the lower linkage is extended, and the lower linkage rotates when the upper linkage is extended. Fig. 44 and 45 illustrate that the wrist joint 824 of the

upper linkages

818, 822 does not travel over the wafer 826 carried by the

lower linkages

816, 820 of the arms. The embodiment shown does not have a bridge. In contrast to fig. 46 and 47, the end effector need not be shaped to avoid interference with the opposite elbow.

Referring now to fig. 46A and 46B, a top view and a side view, respectively, of a robot 840 having an arm 842 is shown. Both linkages are shown in their retracted positions, with each linkage having a dual-

holder end effector

850, 852. The combined upper arm link 844 may be a single piece as depicted in fig. 46A and 46B, or it may be formed of two or more sections 844', 844 "as shown in the example of fig. 47A and 47B. The internal arrangement of the individual links used to drive the arms may be as in figures 15 to 19, for example figure 19. The combined upper arm 844 is driven by a motor. Each of the two

front arms

846, 848 is independently driven by one motor via a belt drive with a conventional pulley. The third links with

end effectors

850, 852 are constrained by belt drives each having at least one non-circular pulley (to compensate for the effect of unequal lengths of the upper arm and forearm). In the illustrated embodiment, the forearm is shorter than the upper arm; alternatively they may be longer. The tape drives in each of the linkages are designed using the technical methods described with respect to fig. 1 and 2. The kinematic equations presented for fig. 1 and 2 can also be used for each of the two linkages of the two arms. In order to rotate the arm, all three actuator axes of the robot need to move the same amount in the direction of rotation of the arm. In order to extend and retract one of the end effector assemblies radially along a linear path, the driver shaft of the common upper arm 844 and the driver shaft coupled to the forearm associated with the active linkage need to move in a coordinated manner in accordance with the inverse kinematics equations for fig. 1 and 2. At the same time, the drive shaft coupled to the other forearm needs to rotate in synchronism with the drive shaft of the common upper arm in order to keep the inactive linkage withdrawn. Referring also to fig. 48 and 49, the arm of fig. 46A and 46B is shown with the

upper linkages

848, 852 extended. Here, the

non-active linkages

846, 850 rotate as the

active linkages

848, 852 extend. For example, the upper linkage rotates when the lower linkage is extended, and the lower linkage rotates when the upper linkage is extended. Fig. 48 and 49 illustrate that the wrist 854 of the upper linkage does not travel over the wafer 856 carried by the lower linkage of the arm. The illustrated embodiment does not have a bridge and the wrist of the upper linkage does not travel over the wafer carried by the lower linkage. Here, the inactive arms are less rotated, allowing for higher movement speeds when the active arms are extended or retracted without load.

Referring now to fig. 50A and 50B, top and side views of a robot 870 having an arm 872 are shown. Both linkages are shown in their retracted positions, with each linkage having a dual

holder end effector

880, 882. The combined upper arm link 974 may be a single piece as depicted in fig. 50A and 50B, or it may be formed of two or more sections as shown in the example of fig. 47A and 47B. The internal arrangement of the individual links used to drive the arms may be as in figures 15 to 19, for example figure 19. The combined upper arm 874 is driven by a motor. Each of the two

front arms

876, 878 is independently driven by one motor via a belt drive having a conventional pulley. The third link with the end effector is constrained by belt drives each having at least one non-circular pulley (to compensate for the effect of unequal lengths of the upper arm and forearm). In the illustrated embodiment, the forearm is shorter than the upper arm; alternatively they may be longer. The tape drives in each of the linkages are designed using the technical methods described with respect to fig. 1 and 2. The kinematic equations presented for fig. 1 and 2 can also be used for each of the two linkages of the two arms. In order to rotate the arm, all three actuator axes of the robot need to move the same amount in the direction of rotation of the arm. In order for one of the end effector assemblies to extend and retract radially along a linear path, the driver shaft of the common upper arm 874 and the driver shaft coupled to the forearm associated with the movable linkage need to move in a coordinated manner in accordance with the inverse kinematics equations for fig. 1 and 2. At the same time, the drive shaft coupled to the other forearm needs to rotate in synchronism with the drive shaft of the common upper arm 874 in order to keep the inactive linkage withdrawn. Referring also to fig. 51, the arm of fig. 50A and 50B is shown with one of the

linkages

878, 882 extended. Here, the

non-movable linkages

876, 880 rotate as the

movable linkages

878, 882 extend. For example, the upper linkage rotates when the lower linkage is extended, and the lower linkage rotates when the upper linkage is extended. The illustrated embodiment has a short forearm link that may be stiff and a short strap that is shorter and in which the forearms are positioned side-by-side to facilitate shallow chambers. Here, the short link may cause more rotation of the inactive arm than in fig. 46 and 47, which may be addressed by a longer upper arm. A bridge 884 is provided wherein the arms and end effector can be designed such that the bridge 884 is spaced from the inactive end effector 880 during extension movement. Here, the base of the end effector features an angled shape 886 as shown.

Referring now to fig. 52A and 52B, top and side views, respectively, of a robot 900 having an arm 902 are shown. Both linkages are shown in their retracted positions, with each linkage having a dual-holder end effector. The internal arrangement of the individual links used to drive the arms may be the same as in figures 21 to 23. Each of the two

upper arms

904, 906 is independently driven by one motor. The

front arms

908, 910 are coupled to a third motor via a belt arrangement each having at least one non-circular pulley. Is constrained by belt drives each having at least one non-circular pulley. The belt drive is designed such that rotation of one of the

upper arms

904, 906 causes the corresponding linkage to extend and retract along a straight line while the other linkage remains stationary. In the illustrated embodiment, the forearm is shorter than the upper arm; alternatively they may be longer. The tape drives in each of the linkages are designed using the technical method described with respect to fig. 5-6. The kinematic equations presented for fig. 5-6 may also be used for each of the two linkages of the two arms. In order to rotate the arm, all three actuator axes of the robot need to move the same amount in the direction of rotation of the arm. In order for one of the end effector assemblies to extend and retract radially along a linear path, the drive shaft of the upper arm associated with the movable linkage needs to be rotated according to the inverse kinematics equations for fig. 5-6, and the other two drive shafts need to be held stationary. Referring also to fig. 53, the arm of fig. 52A and 52B is shown with one of the

linkages

906, 910, 914 extended. Note that the

inactive linkages

904, 908, 912 utilize the bridge 916 to remain stationary while the

active linkages

906, 910, 914 are extended. That is, the left linkage does not need to move when the right linkage is extended, and the right linkage does not need to move when the left linkage is extended, although they may be independently radially moved. The illustrated embodiment has a shorter link that may be stiffer, with a short strap and side-by-side forearms to facilitate shallow chambers. Alternatively, the forearm may be longer than the forearm in a configuration with a bridge.

Referring now to fig. 54-55, a coupled dual arm 930 with opposing

end effectors

938, 940 is shown. Fig. 54A and 54B show top and side views, respectively, of a robot having an arm. Both linkages are shown in their retracted positions with the lateral offset of the end effector corresponding to the difference in joint-to-joint lengths of the upper arm 932 and

forearms

934, 936. The combined upper arm link 932 may be a single piece as depicted in fig. 54, or it may be formed of two or more sections. By way of example, a two-section design may be lighter, with less material, and the left and right sections may be identical components. The internal arrangement of the individual links used to drive the arms may be based on that shown with respect to fig. 18 and 19 or otherwise. The common upper arm 932 is driven by one motor. Each of the two

forearms

934, 936 is independently driven by one motor via a belt drive having a conventional pulley. The third link with

end effectors

938, 940 is constrained by belt drives each having at least one non-circular pulley (compensating for the effects of unequal lengths of the

upper arms

934, 936 and forearm 932). The tape drives in each of the linkages are designed using the technical methods described with respect to fig. 1 or otherwise. The slit shapes presented for fig. 1 can also be used for each of the two linkages of the two arms. Fig. 55A-55C show the arm of fig. 54 as the first 934, 938 and second 936, 940 linkages extend from the retracted position. The lateral offset of the end effector corresponds to the difference in joint-to-joint length of the

upper arms

934, 936 and forearm 932, and the wrists 942, 944 travel along a line that is offset from the trajectory of the center of the wafer by this difference. Note that the inactive linkage rotates when the active linkage is extended. For example, the second linkage rotates when the first linkage is extended, and the first linkage rotates when the second linkage is extended. Fig. 55A depicts an arm in which both linkages are in a retracted position. Fig. 55B shows

first linkages

934, 938 extended. Fig. 55C depicts the

second linkages

936, 940 extended. The illustrated arm has a low profile because the forearm travels in the same plane and the end effector travels in the same plane, allowing for a shallow vacuum chamber with a small volume. Since the retracted position of the wrist of one linkage is constrained by the wrist of the other linkage, the containment radius of the arm can be large, making the arm particularly suitable for applications with a large number of process modules, where the diameter of the chamber is determined by the size of the slot valve. Due to its low profile, the arm may be replaced with an opposing end effector. In the illustrated embodiment, the forearm is shorter than the upper arm; alternatively they may be longer, for example where the front arms are at different elevations and overlap.

Referring to fig. 56-57, a stand-alone dual arm 960 is shown with opposing

end effectors

970, 972. Fig. 56A and 56B show top and side views of a robot with an arm. Both linkages are shown in their retracted positions. In fig. 56, the upper arm 962 of the first linkage is positioned above the upper arm 964 of the second linkage. Alternatively, the upper arm of the second linkage may be located above the upper arm of the first linkage. The internal arrangement of the individual links used to drive the arms may be based on fig. 23 or otherwise. Here, each of the two

upper arms

962, 964 may be independently driven by one motor. The

front arms

966, 968 are coupled to the third motor via a belt arrangement each having at least one non-circular pulley. The third link with the

end effectors

970, 972 is constrained by belt drives each having at least one non-circular pulley. The belt drive is designed such that rotation of one of the upper arms causes the corresponding linkage to extend and retract along a straight line while the other linkage remains stationary. The tape drives in each of the linkages are designed using the technical approach described with respect to fig. 5. The kinematic equations presented for fig. 5 can also be used for none of the two linkages of the two arms. Fig. 57A-57C illustrate the arm of fig. 56 as the

first linkages

962, 966, 970 and the

second linkages

964, 968, 972 extend from the retracted positions. Here, the inactive linkage remains (but need not do so) stationary while the active linkage is extended. That is, the second linkage does not move when the first linkage is extended, and the first linkage does not move when the second linkage is extended. The arm has a low profile because the forearm travels in the same plane and the end effector travels in the same plane, allowing for a shallow vacuum chamber with a small volume. Since the retracted position of the wrist of one linkage is constrained by the wrist of the other linkage, the containment radius of the arm is large, making the arm particularly suitable for applications with a large number of process modules, where the diameter of the chamber is determined by the size of the slot valve. Due to its low profile, the arm may be replaced with an opposing end effector. In the illustrated embodiment, the forearm is shorter than the upper arm; alternatively they may be longer, for example where the front arms are at different elevations and overlap.

Referring now to fig. 58, a coupled dual arm 990 with angularly offset

end effectors

998, 1000 is shown. Fig. 58A and 58B show top and side views of a robot with an arm. Both linkages are shown in their retracted positions. The lateral offsets 1002, 1004 of the end effectors correspond to the difference in the joint-joint lengths of the

upper arms

994, 996 and forearm 992. The combined upper arm link 992 may be a single piece as depicted in fig. 59, or it may be formed of two or more sections. The internal arrangement of the individual links used to drive the arms is based on fig. 18 or fig. 19 or otherwise. Here, the common upper arm 992 may be driven by one motor. Each of the two

front arms

994, 996 may be independently driven by one motor via a belt drive having a conventional pulley. The third links with the

end effectors

998, 1000 are constrained by belt drives each having at least one non-circular pulley (to compensate for the effect of unequal lengths of the upper arm and forearm). The tape drives in each of the linkages are designed using the technical methods described with respect to fig. 1 or otherwise. The kinematic equations presented for fig. 1 can also be used for each of the two linkages of the two arms. Referring also to fig. 59A-59C, the arm of fig. 58 is shown with the left and

right linkages

994, 998, 996, 1000 extended. The lateral offsets 1002, 1004 of the end effector correspond to the difference in the joint-to-joint lengths of the upper arm and forearm, and the wrist joint travels along a line offset from the trajectory of the center of the wafer by this difference. Here, the inactive linkage rotates when the active linkage is extended, e.g., the right linkage rotates when the left linkage is extended and the left linkage rotates when the right linkage is extended. Fig. 59A depicts an arm in which both linkages are in a retracted position. Fig. 59B shows the

left linkages

994, 998 extended. Fig. 59C depicts the

right linkages

996, 1000 extended. Here, the inactive arm rotates when the active arm is extended. In the illustrated embodiment, the forearm is shorter than the upper arm; alternatively they may be longer, for example where the front arms are at different elevations and overlap. In the illustrated embodiment, the end effectors may be 90 degrees apart; any separation angle may alternatively be provided.

Referring now to fig. 60, a stand-alone dual arm 1030 is shown with angularly offset

end effectors

1040, 1042. Here, fig. 60A and 60B show top and side views of a robot having an arm. Both linkages are shown in their retracted positions. In fig. 60, the right upper arm 1034 is located below the left upper arm 1032. Alternatively, the left upper arm may be located below the right upper arm. The internal arrangement of the individual links used to drive the arms can be based on fig. 23. Each of the two

upper arms

1032, 1034 may be independently driven by one motor each. The forearm is coupled to a third motor via a belt arrangement each having at least one non-circular pulley. The third link with the

end effectors

1040, 1042 is constrained by belt drives each having at least one non-circular pulley. The belt drive is designed such that rotation of one of the

upper arms

1032, 1034 causes the corresponding linkage to extend and retract along a straight line while the other linkage remains stationary. The tape drives in each of the linkages are designed using the technical approach described with respect to fig. 5 or otherwise. The kinematic equations presented for fig. 5 can also be used for each of the two linkages of the two arms. Fig. 61A-61C illustrate the arm of fig. 60 with the

left linkages

1032, 1036, 1040, and then the

right linkages

1034, 1038, 1042 extended. Here, the inactive linkage remains (but need not do so) stationary while the active linkage is extended. That is, the left linkage does not move when the right linkage is extended, and the right linkage does not move when the left linkage is extended. Here, the inactive linkage remains stationary while the active linkage is extended. In the illustrated embodiment, the forearm is shorter than the upper arm; alternatively they may be longer, for example where the front arms are at different elevations and overlap. In the illustrated embodiment, the end effectors may be 90 degrees apart; any separation angle may alternatively be provided.

By way of example or otherwise with respect to fig. 62, the third link and

end effector

1060, 1062, each of which may be referred to as a third link assembly, may be designed such that the center of

mass

1064, 1066 is on or near the linear trajectory of the wrist joint 1068, 1070, respectively, as the corresponding linkage of the arm is extended and retracted. This reduces the moment due to the inertial force acting at the center of mass of the third link assembly and the reaction force at the wrist joint, thereby reducing the load on the belt arrangement restraining the third link assembly. Here, the third link assembly may be further designed such that its center of mass is on one side of the wrist joint trajectory when payload is present and on the other side of the trajectory when no payload is present. Alternatively, the third linkage assembly may be designed such that its center of mass is substantially on the wrist trajectory when payload is present, as best line tracking performance is typically required in the presence of payload, as illustrated in fig. 62. In fig. 62, 1L is a linear trajectory of the center of the wrist joint of the left linkage, 2L is the center 1070 of the wrist joint of the left linkage, 3L is the center of mass 1066 of the third link assembly of the left linkage, 4L is a force acting on the third link assembly of the left linkage at the start of acceleration of the extension movement (or deceleration at the end of the retraction movement), and 5L is an inertial force acting at the center of mass of the third link assembly of the left linkage at the start of acceleration of the extension movement (or deceleration at the end of the retraction movement). Similarly, 1R is the linear trajectory of the center of the wrist joint of the right linkage, 2R is the center 1068 of the wrist joint of the right linkage, 3R is the center of mass 1064 of the third link assembly of the right linkage, 4R is the force acting on the third link assembly of the right linkage at the end of deceleration of the extension movement (or at the beginning of acceleration of the retraction movement), and 5R is the inertial force acting at the center of mass of the third link assembly of the right linkage at the end of deceleration of the extension movement (or at the beginning of acceleration of the retraction movement). In the illustrated embodiment, a dual wafer end effector is provided. In alternative aspects, any suitable end effector and arm or linkage geometry may be provided.

In alternative aspects, the upper arm in any of the aspects of the present embodiment may be driven by a motor, either directly or via any kind of coupling or transmission arrangement. Any gear ratio may be used. Alternatively, the belt drive that actuates the second link and constrains the third link may be replaced with any other arrangement having equivalent functionality, such as a belt drive, cable drive, circular and non-circular gears, linkage-based mechanisms, or any combination thereof. Alternatively, for example, in the double and four arm aspects of the present embodiment, the third link of each linkage may be constrained to maintain the end effector radial via a conventional two-stage belt arrangement that synchronizes the third link with a pulley driven by a second motor, similar to the single arm concept of fig. 9. Alternatively, the two-stage belt arrangement may be replaced with any other suitable arrangement, such as a belt drive, cable drive, gear drive, linkage-based mechanism, or any combination thereof. Alternatively, the upper arms in the two-and four-arm aspects of the present embodiment may not be arranged in a coaxial manner. They may have separate shoulder joints. The two linkages of the double and four arms do not require upper arms of the same length and forearms of the same length. The length of the upper arm of one linkage may be different than the length of the upper arm of the other linkage, and the length of the forearm of one linkage may be different than the length of the forearm of the other linkage. The forearm-to-upper arm ratio may also be different for the two linkages. The left and right linkages are interchangeable in terms of the double and quadruple arms of this embodiment having different elevations of the links of the left and right linkages. The two linkages of the double and quadruple arms need not extend in the same direction. The arms may be configured such that the linkages extend in different directions. Two linkages in any of the various aspects of the present embodiments may be made up of more or less than three links (first link being the upper arm, second link being the forearm, and third link being the link with the end effector). In the double and four arm aspects of the present embodiment, each linkage may have a different number of links. In the single-arm aspect of this embodiment, the third link may carry more than one end effector. Any suitable number of end effectors and/or material holders may be carried by the third link. Similarly, in the dual arm aspect of the present embodiment, each linkage may carry any suitable number of end effectors. In either case, the end effectors may be positioned in the same plane, stacked on top of each other, arranged in a combination of two, or arranged in any other suitable manner. Further, for a dual arm configuration, each arm may be independently operable, e.g., in rotation, extension, and/or z (vertical), e.g., as described with respect to pending U.S. patent application serial No. 13/670,004 entitled "robotic system with independent arms" having application date 11/06/2012, which is incorporated herein by reference in its entirety. Accordingly, all such modifications, combinations and variations are intended to be included herein.

Referring now to fig. 63, a graphical representation 1100 of an exemplary pulley is shown. An exemplary pulley profile may be for an arm having unequal link lengths as will be described. By way of example, graph 1100 may show a profile for a wrist pulley where the elbow pulley is circular. Here, the following example designs are used for the figures: re/l2 ═ 0.2, where Re is the radius of the elbow pulley and l2 is the joint-joint length of the forearm. Alternatively, any suitable ratio may be provided. For the sake of clarity, the figures show extreme design situations compared to pulleys for two-link arms. The outermost contour 1110 is for l2/l1 ═ 2, where l2 is the joint-to-joint length of the forearm and l1 is the joint-to-joint length of the upper arm, for example, this case represents a longer forearm. The middle profile 1112 is for l2/l1 ═ 1, for example, with equal link lengths. The innermost profile 1114 is for l2/l1 ═ 0.5, for example, this case represents the shorter forearm. In the illustrated embodiment, a polar coordinate system 1120 is used. Here, the radial distance is normalized with respect to the radius of the elbow pulley, for example, expressed as a multiple of the radius of the elbow pulley. In other words, Rw/Re is shown, where Rw represents the polar coordinates of the wrist pulley and Re represents the polar coordinates of the elbow pulley. The angular coordinate is in degrees and the null point is directed along the direction 1122 of the end effector, e.g., the end effector is directed to the right with respect to the figure.

Referring now to fig. 64 and 65, two additional configurations of

arms

1140 and 1160 having unequal link lengths are shown. The arm 1140 is shown as having a forearm 1144 that is longer than an upper arm 1142, wherein a single arm configuration may utilize features as disclosed with respect to fig. 1-4 and 5-8 or otherwise. In the illustrated embodiment, two

end effectors

1146, 1148 supporting

respective substrates

1150, 1152 are rigidly connected to each other and are directed in opposite directions. The substrate travels on a radial path that coincides with the center 1156 of the robot 1140 and is offset 1154 from the wrist as shown. Similarly, the arm 1160 is shown having a shorter forearm 1164 than the upper arm 1162, where a single arm configuration may utilize features as disclosed with respect to fig. 1-4 and 5-8 or otherwise. In the illustrated embodiment, two

end effectors

1166, 1168 supporting

respective substrates

1170, 1172 are rigidly connected to each other and are directed in opposite directions. The substrate travels on a radial path that coincides with the center 1176 of the robot 1160 and is offset 1174 from the wrist as shown. Features of the disclosed embodiments may be shared here similarly to any of the other disclosed embodiments.

Referring now to fig. 66 and 67, the disclosure describes a dual-arm robot 1310 having a stacked and side-by-side end effector configuration. The apparatus may be used in combination with a transport mechanism and apparatus as disclosed in U.S. publication No. 2013/0071218 published on 3/21/2013, which is based on U.S. patent application serial No. 13/618,117 filed on 9/14/2012 and entitled "low variability robot" or U.S. patent application serial No. 14/601,455 filed on 21/1/2015 and entitled "substrate transport platform," both of which are hereby incorporated by reference in their entirety. Alternatively, the present embodiments may be used in any suitable device or application. The disclosed apparatus may provide a robot 1310 having two end effectors that (i) has a small footprint such that it may move and rotate in a narrow lane, (ii) may access the same station with both end effectors either independently or simultaneously, and (iii) may access side-by-side offset stations either independently or simultaneously.

An example embodiment of a robot 1310 is diagrammatically depicted in fig. 66A-66D and 67A-67D. The robot may be comprised of a robot drive unit 1312 having a pivot base 1314 about an axis 1334 and a robot arm 1316. Robot arm 1316 may feature two linkages, namely a left linkage 1318 and a right linkage 1320. Fig. 66A to 66D show a robot in which both linkages are retracted, and fig. 67A to 67D show a robot in which the left linkage 1318 is extended.

The left linkage 1318 may be comprised of a left upper arm 1322, a left forearm 1324, and a left end effector 1326. The left upper arm 1322 may be coupled to the base via a rotational joint or axis 1336, the left forearm 1324 may be coupled to the left upper arm 1322 by another rotational joint or axis 1338, and the left end effector 1326 may be coupled to the left forearm 1324 by yet another rotational joint or axis 1340.

Similarly, right linkage 1320 may be comprised of a right upper arm 1328, a right front arm 1330, and a right end effector 1332. The right upper arm 1328 may be coupled to the base via a rotational joint or axis 1342, the right forearm 1330 may be coupled to the right upper arm 1328 by another rotational joint or axis 1344, and the right end effector 1332 may be coupled to the right forearm 1330 by yet another rotational joint or axis 1346.

The joint-to-joint length of the left forearm may be longer than the joint-to-joint length of the left upper arm. Alternatively, the joint-to-joint length of the left forearm may be equal to the joint-to-joint length of the left upper arm. In yet another alternative, the left forearm and the left upper arm may have any other suitable length.

Similarly, the joint-to-joint length of the right forearm may be longer than the joint-to-joint length of the right forearm. Alternatively, the joint-to-joint length of the right forearm may be equal to the joint-to-joint length of the right upper arm. In yet another alternative, the right forearm and right upper arm may have any other suitable length.

In the example of fig. 66A to 66D and 67A to 67D, the joint-joint lengths of the left and right upper arms and the left and right front arms are shown to be the same. Similarly, the left and right end effectors (including the dimensions of length and lateral offset) are shown to be the same. However, the linkage may feature any suitable size of upper arm, forearm, and end effector.

To enable two end effectors to simultaneously access stations that are offset side-by-side, the distance between the joints coupling the left and right upper arms to the base may be selected to satisfy the following relationship:

D＝2d0 (1)

where D-the center-to-center distance (m) between the stations offset side-by-side, and D0-the distance (m) between the joints coupling the left and right upper arms to the base.

Additionally, to enable two end effectors to simultaneously access the same station, the linkage dimensions may be selected to satisfy the following relationship:

d0＝l2L–l1L+d3L+l2R–l1R+d3R (2)

the following nomenclature is used in equation (2) above: d3L, d3R, l1L, l1R, l2L, and l2R, the lateral offset (m) of the left forearm, the lateral offset (m) of the right end effector, the joint-joint length (m) of the left upper arm, the joint-joint length (m) of the right upper arm, and the joint-joint length (m) of the right forearm.

When the robot arm is symmetrical, i.e. the left and right linkages have the same dimensions, equation (2) can be simplified as follows:

d0＝2(l2–l1+d3)(3)

where d3 is the lateral offset of the end effector (m), l1 is the joint-joint length of the upper arm (m), and l2 is the joint-joint length of the forearm (m).

Fig. 68A and 68B diagrammatically illustrate

example arrangements

1398, 1438 of base and individual links (i.e., upper arm, forearm, and end effector) that may be used to drive the robot. As depicted in fig. 68A and 68B, the base may be driven by a

driver shaft

1400, 1448, e.g., T0.

The left upper arms 1402, 1454 may be actuated by driver axes T1L 1420, 1440. The left front arm 1406, 1456 may be coupled to another drive shaft T2L 1422, 1442 via a belt arrangement having at least one non-circular pulley. The band arrangement may be designed such that rotation of the left upper arm causes linear extension and retraction of the left wrist joint (i.e., the joint coupling the left end effector to the left forearm) along a desired linear path parallel to the left end effector.

The left end effector 1410 may be constrained by another belt arrangement having at least one non-circular pulley that compensates for the effects of unequal lengths of the left upper arm and left forearm so that the left end effector may travel along a straight line while maintaining a desired orientation.

Alternatively, if l1L ═ l2L, a conventional pulley may be utilized, as shown in fig. 68B. In this embodiment, the belt arrangement coupling the left forearm to the shaft T2L is designed such that the diameter of the pulley coupled to the shaft T2L is twice the diameter of the pulley coupled to the left forearm. The belt arrangement constraining the left end effector is designed such that the diameter of the pulley attached to the left upper arm is half the diameter of the pulley attached to the left end effector.

Similarly, the right upper arm 1404, 1450 can be actuated by a

drive axis T1R

1424, 1444. The right front arm 1408, 1452 may be coupled to another

drive shaft T2R

1426, 1446 via a belt arrangement having at least one non-circular pulley. The band arrangement may be designed such that rotation of the right upper arm causes linear extension and retraction of the right wrist joint (i.e., the joint coupling the right end effector to the right forearm) along a desired linear path parallel to the right end effector 1412.

The right end effector 1412 may be constrained by another belt arrangement having at least one non-circular pulley that compensates for the effects of the unequal lengths of the right upper arm and right forearm so that the left end effector may travel along a straight line while maintaining the desired orientation.

Alternatively, if l1R ═ l2R, a conventional pulley may be utilized, as shown in fig. 68B. In this embodiment, the belt arrangement coupling the right front arm to the shaft T2R is designed such that the pulley coupled to the shaft T2R is twice the diameter of the pulley coupled to the right front arm. The belt arrangement constraining the right end effector is designed such that the diameter of the pulley attached to the right upper arm is half the diameter of the pulley attached to the right end effector.

In order to turn the entire robot arm, all of the drive axes (i.e., T0, T1L, T2L, T1R, and T2R) need to move the same amount relative to the fixed reference frame in the desired rotational direction of the arm (or drive axis T0 needs to move while the other drive axes may be considered stationary relative to the base). This is schematically depicted in fig. 69A to 69C. In this particular example, the entire robot arm is rotated 180 degrees in a counterclockwise direction.

In order for the left end effector to extend and retract along a linear path, driver axis T1L needs to be moved to an angle determined based on the inverse kinematics of the left linkage while axes T0 and T2L are held stationary. The robot 1500 is shown diagrammatically in fig. 69D with the left end effector left and

right arms

1502, 1504 in an extended state from the initial position of fig. 69A.

Similarly, to extend and retract the right end effector along a linear path, driver axis T1R needs to move an angle determined based on the inverse kinematics equation for the right linkage while axes T0 and T2R are held stationary. The robot is depicted diagrammatically in fig. 69E with the right end effector in an extended state from the initial position of fig. 69A.

The two left and right end effectors of the robot may be simultaneously extended and retracted along a linear path by rotating the driver shafts T1L and T1R in opposite directions and by the same amount if the left and right linkages feature the same dimensions. The robot is shown diagrammatically in fig. 69F with both left and right end effectors in a state of being extended from the initial position of fig. 69A.

The motions described above with respect to fig. 69D-69F allow the robot to either independently or simultaneously extend/retract the end effector to/from the same station. Thus, the robot can pick/place material, such as semiconductor wafers, from/to the same station independently or simultaneously along the linear path 1510 using two end effectors.

The left and

right linkages

1502, 1504 may also be rotated independently. To rotate the left linkage, the driver shafts T1L and T2L need to move the same amount in the desired rotational direction. Similarly, to rotate the right linkage, the driver shafts T1R and T2R need to be rotated the same amount in the desired rotational direction.

When the left and right linkages are individually rotated by 180 degrees, the left and right end effectors become laterally offset, as depicted in the example illustrations shown in fig. 70A-70C. In this particular example, the left linkage 1502 rotates in a clockwise direction and the right linkage 1504 simultaneously rotates in a counter-clockwise direction (preventing the risk of collision of the left and right wrist joints). However, the left and right linkages may rotate independently in sequence, in the same direction, or in any other suitable manner.

As a result of the individual rotations of the left and right linkages described above, the arms are reconfigured so that the centers of the left and right end effectors are laterally offset by a distance D as long as the dimensions of the robot satisfy the conditions of equations (1) and (2).

In the case where reconfiguration of the upper end effector offset by individual rotation of the left and right linkages occurs before or after rotation of the entire arm, the movements can be conveniently mixed to minimize the overall duration.

Once in the position illustrated in fig. 70C, the left end effector may be extended and retracted again along linear path 1512 by moving driver shaft T1L while holding shafts T0 and T2L stationary. Similarly, the right end effector may be extended and retracted along a linear path by moving driver shaft T1R while holding shafts T0 and T2R stationary. And, finally, the two left and right end effectors of the robot may be simultaneously extended and retracted along a linear path by rotating the driver shafts T1L and T1R in opposite directions and by the same amount if the left and right linkages feature the same dimensions.

The robot is shown diagrammatically in fig. 70D in a state in which the left end effector is extended from the initial position of fig. 70C; the robot in a state where the right end effector is extended from the initial position of fig. 70C is schematically depicted in fig. 70E; and the robot in a state where both left and right end effectors are extended from the initial position of fig. 70C is diagrammatically shown in fig. 70F.

The motions described above with respect to fig. 70E-70F allow the robot to extend/retract the end effector to/from two side-by-side offset stations. Thus, the robot is able to pick up/place materials such as semiconductor wafers from/to two side-by-side offset stations, either independently or simultaneously.

In the event that the access paths to the stations offset side-by-side are not parallel (e.g.,

path

1514 or 1516 in fig. 71), the robot may individually rotate the left and right linkages such that the direction of their extend/retract paths is aligned with the access paths to the stations. An example of such a scene is diagrammatically illustrated in the diagrams of fig. 71A to 71C. Assuming the initial position of diagram 71A, the left and right linkages may be rotated to reconfigure the arms so that the end effector is laterally and angularly offset as depicted in diagram 71B. In this particular example, the angular offset between the left and right end effectors is 30 degrees. Starting from the withdrawn position of diagram 71B, the left linkage may be extended as shown in diagram 71C either independently or simultaneously.

The robot may also access stations 180 degrees apart either independently or simultaneously as depicted in example schema 71D and schema 71E. In this particular example, assuming the starting position of diagram 71A, the left and right linkages may first be rotated to the configuration of diagram 71D, and then the left and/or right end effectors may be extended as shown in diagram 71E, either independently or simultaneously.

While both left and right linkages are shown extended in illustration 71E, only one of the two linkages may be extended in alternative aspects. Here, the reach of the linkage (measured from the center of the robot represented by the axis of the driver shaft T0) is longer in the configuration shown in diagram 71E, and thus this configuration can be used for stations located further away from the robot.

The robot may be driven using a three-to five-axis drive arrangement, depending on the number of degrees of freedom required in a particular application.

The 3-axis drive arrangement may include three independently controlled motors M0, M1, and M2, as illustrated by the two examples 1600, 1700 of fig. 72A and 72B and 72C and 72D.

In fig. 72A-72D, diagram 72A and diagram 72B show top and side views, respectively, of an example arrangement 1600 of a robotic drive unit and arm base 1618, with motor M0 directly coupled to shaft T01602 of actuation base 1618, motor M11604 directly attached to shaft T1L 1610 driving the left upper arm, and motor M21606 directly attached to shaft T2R 1616 coupled with the right front arm. Further, the use of two

belt arrangements

1620, 1622 causes the shafts T1L 1610 and T1R 1614 to rotate in opposite directions as compared to the shafts T2L 1612 and T2R 1616, respectively. This is achieved by virtue of the cross-belt arrangement 1620 between axes T1L and T1R and similarly by virtue of the further cross-belt arrangement 1622 between axes T2L and T2R.

Alternatively, the drive 1700 may have motors M01702, M11704, and M21706 arranged in the drive unit, and motion may be transferred from the motors M1 and M2 to the shafts T1L 1710, T1R 1714 and T2L 1712, T2R1716, respectively, using the tape drives 1720, 1722 as illustrated in the examples of diagram 72C and diagram 72D.

In yet another alternative, any suitable combination of direct coupling between the motor and the drive shaft and belt arrangement may be employed. In general, any suitable means of providing the desired kinematic relationship in the transmission of motion between the motor and the drive shaft may be used.

When using the example 3-axis drive according to fig. 72A-72D, the robot may perform all the operations defined in fig. 69-71, except for independent extension and retraction of the left and right linkages (illustrations D and E in fig. 69 and 70).

The 4-axis drive arrangement may include four independently controlled motors as illustrated in examples 1800, 1900 illustrating fig. 73A and 73B. Diagrams 73A and 73B show top and side views of the robot driver unit and arm base 1802. The shafts T01804, T1L 1808 and T1R 1810 may be actuated in an independent manner by motors M01804, M1L 1808 and M1R 1810, respectively. Motor M21806 may be used to actuate shafts T2L 1812 and T2R 1814 so that the two shafts rotate in opposite directions. In the particular example illustrated in fig. 73A and 73B, this is achieved by virtue of a straight belt arrangement 1820 between a pulley coupled to motor M2 and shaft T2L and a crossed belt arrangement 1822 between another pulley coupled to motor M2 and shaft T2R.

Alternatively, any combination of direct coupling and belt arrangements or any other suitable means of transmission of motion between the motor and the driver shaft may be employed to facilitate independent actuation of the shafts T0, T1L and T1R and coupled actuation of the shafts T2L and T2R.

When using such a 4-axis drive arrangement, the robot can perform all operations according to fig. 69 to 71, including independent extension and retraction of the left and right linkages.

The 5-axis driver arrangement 1900 may include five independently controlled motors M01904, M1L 1906, M2L 1908, M1R 1910, and M2R 1912, which may be directly coupled to driver axes T0, T1L, T2L, T1R, and T2R, as described in the illustrated example in fig. 73C and 73D, where illustration 73C illustrates a top view of driver unit 1900 and base 1902 and illustration 73D illustrates a side view thereof; with the tape drive expanded by the example illustrated in fig. 72C and 72D; a combination of direct coupling and belt arrangement is used, or in any other suitable manner that can facilitate the transfer of motion from the motor to the drive shaft.

When using the 5-axis drive arrangement, the robot can perform all operations according to fig. 69 to 71. Additionally, the left and right linkages may be operated in a completely independent manner, including independent rotation, which is not possible with 3-axis and 4-axis drive arrangements.

Another example internal arrangement of the base and linkage of the robot 2010 of fig. 66 is diagrammatically depicted in fig. 74A. Again, the base 2012 may be driven by a driver shaft T0.

The left 2014 upper arm may be actuated by drive axis T1L. The left forearm may be driven by another drive shaft T2L via a belt arrangement with a conventional pulley. The left end effector may be constrained by another belt arrangement having at least one non-circular pulley that compensates for the effects of unequal lengths of the left upper arm and left forearm, such that the left end effector may travel along a straight line while maintaining a desired orientation. Alternatively, if l1L ═ l2L, then a conventional pulley may be utilized, as shown in fig. 74B, where arm 2030 has base 2032, left arm 2034, and right arm 2036.

Similarly, the right 2016 upper arm may be actuated by drive shaft T1R. The right forearm may be driven by another drive shaft T2R via a belt arrangement with a conventional pulley. The right end effector may be constrained by another belt arrangement having at least one non-circular pulley that compensates for the effects of unequal lengths of the right upper arm and the right forearm, such that the right end effector may travel along a straight line while maintaining a desired orientation. Alternatively, if l1R ═ l2R, a conventional pulley may be utilized, as shown in fig. 74B.

In order to turn the entire robot arm, all of the drive shafts (i.e., T0, T1L, T2L, T1R, and T2R) need to move the same amount relative to the fixed reference frame in the desired direction of rotation of the arm (or drive shaft T0 needs to move while the other drive shafts are stationary relative to the base).

In order for the left end effector to extend and retract along a linear path, the driver shafts T1L and T2L need to move in a coordinated manner according to the inverse kinematics equations of the left linkage. Similarly, to extend and retract the right end effector along a linear path, the driver shafts T1R and T2L need to move in a coordinated manner according to the inverse kinematics equation of the right linkage. Example kinematic equations can be found above.

The two end effectors of the robot may be extended and retracted along a linear path by simultaneously rotating the driver axes T1L, T2L and T1R, T2R in the manner described above for independent extension of the left and right end effectors.

The left and right linkages may also be rotated independently. To rotate the left linkage, the driver shafts T1L and T2L need to move the same amount in the desired rotational direction. Similarly, to rotate the right linkage, the driver shafts T1R and T2R need to move the same amount in the desired rotational direction. Similar to fig. 68A and 68B, when the left and right linkages are individually rotated 180 degrees, the left and right end effectors become laterally offset, see diagrams 70A-70C.

In view of the above motion capabilities, a robot having an internal arrangement according to fig. 74A and 74B may perform the same operations as outlined in fig. 69 to 71.

The base and linkage with the internal arrangement of fig. 74A and 74B may be driven by the 3-axis and 5-axis driver arrangements of fig. 72 and 73C, 73D, respectively.

Another example embodiment of a robot 2100 is depicted in the illustrations of fig. 75A and 75B. Diagram 75A shows a top view of a robot with both linkages retracted and diagram 75B depicts a robot with both end effectors extended.

An example internal arrangement of a robot is illustrated diagrammatically 2330 in fig. 76A. In the figure, the base 2332 is shown with

linkages

2334, 2336 having upper arms and forearms of equal length and a circular pulley with

linkages

2334, 2336; however, unequal length and non-circular pulleys may be utilized.

The robot may be actuated by the drive arrangement described earlier with reference to fig. 72 and 73.

An alternative internal arrangement of the robot of illustrations 75A and 75B is shown diagrammatically 2360 in fig. 76B. In the figure, base 2362 is shown with

linkages

2364, 2366 having upper and lower arms of equal length and a circular pulley as

linkages

2364, 2366; however, unequal length and non-circular pulleys may be utilized.

The robot may be actuated by a drive arrangement according to fig. 72 and 73C, 73D.

Yet another example embodiment of a robot 2200 is depicted in the illustrations of fig. 75C and 75D. Diagram 75C shows a top view of the robot with both linkages retracted and diagram 75D depicts the robot with both end effectors extended. Diagrams 75C and 75D show the linkage of the robot in a left-hand configuration. Alternatively, the linkage may be configured in a right-handed arrangement, as shown in illustrations 75E and 75E with robot 2300.

An example internal arrangement according to the embodiments of illustrations 75C and 75D is diagrammatically illustrated 2390 in fig. 76C. Similarly, an example internal arrangement according to the embodiments of diagram 75E and diagram 75E is illustrated diagrammatically 2430 in fig. 76D. In fig. 76C and 76D,

linkages

2394, 2396, 2434, 2436 with equal length upper and forearm and with circular pulleys are shown; however, unequal length and non-circular pulleys may be utilized.

The robot may be actuated by a drive arrangement according to fig. 77A to 77D, 78A to 78B and 73C and 73D. In fig. 77A and 77B, the driver 2500 has a base 2504 driven by a motor M02502. M12506 drives T1l 2510 and M22508 drives T2r 2516, with T1l 2510 and T1r 2514 constrained by a belt and T2l 2512 and T2r 2516 constrained by a belt. In fig. 77C and 77D, the drive 2560 has a base 2562 driven by a motor M02564. M12566 drives T1l 2570 and M22568 drives T2r 2576, where T1l 2570 and tlr 2574 are constrained by the belts and T2l 2572 and T2r 2576 are constrained by the belts. In fig. 78A and 78B, a driver 2700 has a base 2702 driven by a motor M02704. M1l 2706 drives T1l and M1r 2708 drives T1r and M22710 drives T2r 2714 and T2l 2712 through the belt.

When utilizing a 3-axis drive arrangement, such as the example according to fig. 77, the robot may perform all of the operations defined in fig. 69 and 70, except for independent extension and retraction of the left and right linkages (illustrations D and E in fig. 69 and 70). It is not possible to perform the simultaneous extension and retraction of fig. 71 along non-parallel and opposite paths.

When using a 4-axis drive arrangement such as the example of fig. 78, the robot can perform all operations according to fig. 69 and 70, including independent extension and retraction of the left and right linkages. It is not possible to perform the simultaneous extension and retraction of fig. 71 along non-parallel and opposite paths.

When using the 5-axis drive arrangement, the robot can perform all operations according to fig. 69 and 71. Additionally, the left and right linkages may be operated in a completely independent manner, including independent rotation, which is not possible with 3-axis and 4-axis drive arrangements.

The disclosure shows advantageous reach-to-hold ratios. In combination with the 3-axis drive arrangement of fig. 77A and 77B, it also provides a low profile and low complexity. Additionally, in combination with the 4-axis drive arrangement, the disclosed supports independent extension of the left and right linkages.

Alternative internal arrangements of the illustrated example embodiments of fig. 75A-75D are shown diagrammatically at 2800, 2830 in fig. 79A and 79B, respectively. In the figures, the

base

2802, 2832 is shown with

linkages

2804, 2806, 2834, 2836, the

linkages

2804, 2806, 2834, 2836 having upper arms and forearms of equal length and having circular pulleys; however, unequal length and non-circular pulleys may be utilized.

The robot may be actuated by a drive arrangement according to fig. 77 and 73C and 73D.

Although the left and right linkages are shown in the figures as having the same dimensions, the left linkage may have different dimensions than the right linkage, and the driver unit may be configured to reflect the differences in dimensions.

The robot may be designed such that some of its links (such as the upper arm and/or forearm) are below one or both of the end effectors and the other links are above one or both of the end effectors.

When the terms "belt arrangement" and "belt drive" are used, they generally refer to means for transmitting motion, force and/or torque, including belts, cables, gears or any other suitable arrangement.

Although the motors of the robots are shown throughout the figures as being directly attached to the shafts, pulleys, and other driven components, the motors may be coupled to the driven components via additional belts, cables, gears, or any other suitable arrangement that may transmit motion, force, and/or torque.

Although the motors of the robot are depicted throughout the text in the figures as being in the driver unit or base, the motors may be located within the robot arm, e.g. as part of the upper arm or forearm, or integrated into the revolute joints of the robot.

The driver unit of the robot may further include a vertical lift mechanism to adjust the elevation of the entire robot arm. Alternatively, the driver unit may comprise two vertical lifting mechanisms, one for the left linkage and the other for the right linkage, to adjust the elevation of the left and right linkages independently. Here, the end effectors may be stacked or set at the same horizontal height or otherwise independently positioned on the z-axis.

In alternative embodiments, any number and any type of suitable mechanisms may be used within the robot drive and/or robot arm to control the elevation of the left and right end effectors of the robot.

The robot may further comprise a traverse mechanism (traverse mechanism) which may allow the robot to move, for example, along a passageway in which it is mounted.

In another embodiment, the robot may be designed to operate in an inverted configuration, e.g., with the support disposed from the top rather than from the bottom.

The robot may be combined with another robot of the same or similar type, e.g., in an inverted configuration, to provide a system with four end effectors that can support rapid material changes.

The robot may be designed to operate in a particular environment, such as a vacuum, which may include the use of static and/or dynamic seals and other means of isolating some of the components of the robot from the environment in which it operates.

Fig. 80A shows a system 2900 with a robot. The robot driver unit 2904 may be configured to be movable relative to a stationary portion 2902 of the system as indicated by

arrows

2906, 2908. As an example, the robot drive unit may be on a rail, linear bearing, magnetic bearing, or may be coupled to the stationary portion of the system in any suitable manner that allows the robot drive unit to move relative to the stationary portion of the system. As an example, the robot driver unit may be actuated by an electric linear motor with windings in the driver unit, by an electric linear motor with windings in a stationary part of the system, by means of a magnetic coupling, using a pneumatic or hydraulic actuator, by means of a ball screw, by means of a cable or belt, or with any other suitable arrangement that can actuate the robot driver unit relative to a stationary part of the system. As described in the original detailed description, the robot driver unit may include a pivot base and a robot arm. In illustration (a), the pivoting bottom is actuated relative to the robotic driver unit as indicated with an arrow.

Fig. 80B shows a system 3000 having an arrangement in which the pivot base 3004 is actuated directly relative to the stationary portion 3002 of the system on the side of the pivot base as indicated by

arrows

3006, 3008. When both sides of the pivot base are actuated synchronously in the same direction by the same amount, the entire robot translates in the corresponding direction. When the sides of the pivot base are actuated simultaneously in opposite directions by the same amount, the pivot base rotates while its center remains stationary. Any combination of translation and rotation may be obtained by actuating the sides of the pivot base accordingly. As an example, the base may be actuated by an electric linear motor with windings in the pivot base, by an electric linear motor with windings in a stationary part of the system, by means of a magnetic coupling, by means of a ball screw, by means of a cable or belt, or with any other suitable arrangement that can actuate the pivot base relative to a stationary part of the system.

In accordance with one aspect of an exemplary embodiment, an apparatus comprises: at least one driver; a first robotic arm comprising a first upper arm, a first forearm, and a first end effector, wherein the first upper arm is connected to the at least one drive at a first axis of rotation; and a second robot arm comprising a second upper arm, a second forearm, and a second end effector, wherein the second upper arm is connected to the at least one drive at a second axis of rotation spaced from the first axis of rotation; wherein the first and second robot arms are configured to position the end effector in a first retracted position for at least partially stacking substrates located on the end effector one on top of the other, wherein the first and second robot arms are configured to extend the end effector from the first retracted position in a first direction along parallel first paths that are at least partially directly above the other, and wherein the first and second robot arms are configured to extend the end effector in at least one second direction along second paths that are not spaced apart from each other, wherein the first upper arm and the first forearm have different effective lengths, and wherein the second upper arm and the second forearm have different effective lengths.

In accordance with another aspect, the apparatus includes at least one non-circular pulley and a first band connecting the at least one drive to the first forearm at a first joint between the first upper arm and the first forearm.

In accordance with another aspect, the apparatus includes a second strap connecting the first end effector to the first joint at a wrist joint of the first end effector to the first forearm.

According to another aspect, an apparatus includes wherein the first and second end effectors each have a generally L-shape.

In accordance with another aspect, an apparatus includes a first circular pulley and a first belt connecting at least one drive to a second circular pulley at a first joint between a first upper arm and a first forearm, where the first and second pulleys have different diameters.

According to another aspect, the apparatus comprises wherein the first path follows a straight line from the first retracted position.

According to another aspect, the apparatus includes wherein the first and second robot arms are configured to provide the second retracted position to position the end effector such that the substrates positioned on the end effector are not stacked one on top of the other.

In accordance with another aspect, the apparatus includes a controller configured to control the at least one drive to move the first and second robot arms substantially simultaneously along the first path from the first retracted positions and to move the first and second robot arms individually or simultaneously along the second path.

In accordance with another aspect, a method comprises: providing a first robotic arm comprising a first upper arm, a first forearm, and a first end effector, wherein the first upper arm and the first forearm have different effective lengths; providing a second robot arm comprising a second upper arm, a second forearm, and a second end effector, wherein the second upper arm and the second forearm have different effective lengths; connecting the first upper arm to the at least one drive at a first axis of rotation; and connecting the second upper arm to the at least one drive at a second axis of rotation spaced from the first axis of rotation, wherein the first and second robot arms are configured to position the end effector in a first retracted position for at least partially stacking substrates positioned on the end effector one on top of the other, wherein the first and second robot arms are configured to extend the end effector in a first direction from the first retracted position along parallel first paths at least partially positioned directly above the other, and wherein the first and second robot arms are configured to extend the end effector in at least one second direction along second paths spaced from each other that are not positioned one above the other.

In accordance with another aspect, the method includes at least one non-circular pulley at the first axis of rotation and a first belt connecting the at least one drive to the first forearm at a first joint between the first upper arm and the first forearm.

In accordance with another aspect, a method includes connecting a first end effector to a second strap of a first joint at a wrist joint of the first end effector to a first forearm.

In accordance with another aspect, a method includes a first circular pulley and a first belt connecting at least one drive to a second circular pulley at a first joint between a first upper arm and a first forearm, where the first and second pulleys have different diameters.

According to another aspect, the method includes wherein the first and second robot arms are configured to provide the first path along a straight line from the first retracted position.

According to another aspect, a method includes wherein the first and second arms are configured to provide a second retracted position to position the end effector such that substrates positioned on the end effector are not stacked one on top of the other.

According to another aspect, the method includes connecting a controller to the at least one drive, the controller configured to control the at least one drive to move the first and second robot arms substantially simultaneously along the first path from the first retracted positions and to move the first and second arms separately or simultaneously along the second path.

In accordance with another aspect, a method comprises: positioning respective first and second end effectors of first and second robot arms in first retracted positions for stacking substrates located on the end effectors at least partially one on top of the other, wherein the first robot arm comprises a first upper arm, a first forearm, and a first end effector, wherein the first upper arm is connected to at least one drive at a first axis of rotation, and wherein the second robot arm comprises a second upper arm, a second forearm, and a second end effector, wherein the second upper arm is connected to at least one drive at a second axis of rotation spaced from the first axis of rotation; moving the first and second robot arms to move the end effector from the first retracted position in a first direction along parallel first paths at least partially directly above one another; and moving the first and second robot arms to move the end effector to extend the end effector in at least one second direction along a second path spaced from one another that is not one above the other.

In accordance with another aspect, the method includes wherein moving the first and second robot arms includes at least one non-circular pulley and a first belt connecting at least one drive to the first forearm at a first joint between the first upper arm and the first forearm.

In accordance with another aspect, the method includes wherein moving the first and second robot arms includes connecting the first end effector to the second joint at a wrist joint of the first end effector to the second forearm.

In accordance with another aspect, the method includes wherein moving the first and second robot arms includes a first circular pulley and a first belt connecting at least one drive to a second circular pulley at a first joint between the first upper arm and the first forearm, wherein the first and second pulleys have different diameters.

In accordance with another aspect, a method includes a controller controlling at least one drive to move the first and second robot arms substantially simultaneously along the first path from the first retracted positions and to move the first and second robot arms separately or simultaneously along the second path.

In accordance with another aspect, an apparatus comprises: a first robotic arm comprising a first upper arm, a first forearm, and a first end effector; a second robot arm comprising a second upper arm, a second forearm, and a second end effector; and a drive connected to the first and second robot arms, wherein the first upper arm is connected to the drive at a first axis of rotation, wherein the second upper arm is connected to the drive at a second axis of rotation spaced from the first axis of rotation, wherein the drive includes only three motors for rotating the first and second upper arms, wherein the first and second robot arms are configured to position the end effector in the first retracted position for at least partially stacking substrates positioned on the end effector one on top of the other, wherein the first and second robot arms are configured to extend the end effector from the first retracted position in a first direction along parallel first paths at least partially directly above one another, and wherein the first and second robot arms are configured to extend the end effector in at least one second direction along a second path spaced from one another that is not above one another.

In accordance with another aspect, the apparatus includes wherein the first upper arm and the first forearm have different effective lengths, and wherein the second upper arm and the second forearm have different effective lengths.

In accordance with another aspect, the apparatus includes at least one non-circular pulley and a first band connecting the drive to the first forearm at a first joint between the first upper arm and the first forearm.

In accordance with another aspect, an apparatus includes a first circular pulley and a first belt connecting a drive to a second circular pulley at a first joint between a first upper arm and a first forearm, where the first and second pulleys have different diameters.

In accordance with another aspect, the apparatus includes a controller configured to control the drive to move the first and second robot arms substantially simultaneously along the first path from the first retracted positions and to move the first and second robot arms separately or simultaneously along the second path.

According to another aspect, the apparatus includes wherein the three motors are aligned on a common axis.

According to another aspect, the apparatus comprises wherein the three motors are located on three respective spaced axes.

In accordance with another aspect, the apparatus includes a z-axis motor connected to the drive to move the drive and the first and second robot arms vertically.

In accordance with another aspect, a method comprises: positioning respective first and second end effectors of first and second robot arms in first retracted positions for stacking substrates located on the end effectors at least partially one on top of the other, wherein the first robot arm comprises a first upper arm, a first forearm, and a first end effector, wherein the first upper arm is connected to a drive at a first axis of rotation, and wherein the second robot arm comprises a second upper arm, a second forearm, and a second end effector, wherein the second upper arm is connected to the drive at a second axis of rotation spaced from the first axis of rotation; moving the first and second robot arms to move the end effector from the first retracted position in a first direction along parallel first paths at least partially directly above one another; moving the first and second robot arms to move the end effector to extend the end effector in at least one second direction along a second path spaced from one another that is not one above the other; rotating the first and second robot arms together about a third axis of rotation spaced from the first and second axes of rotation, wherein movement in the first direction from the first retracted position, movement and rotation extending the end effector in at least one second direction utilizes only three motors of the drive.

In accordance with another aspect, the method includes wherein moving the first and second robot arms includes at least one non-circular pulley and a first band connecting the drive to the first forearm at a first joint between the first upper arm and the first forearm.

In accordance with another aspect, the method includes wherein moving the first and second robot arms includes a first circular pulley and a first belt connecting the drive to a second circular pulley at a first joint between the first upper arm and the first forearm, wherein the first and second pulleys have different diameters.

According to another aspect, the method includes wherein the controller is further comprised to control the motors of the drives to move the first and second robot arms substantially simultaneously along the first path from the first retracted positions and to move the first and second robot arms individually or simultaneously along the second path.

In accordance with another aspect, a method comprises: providing a first robotic arm comprising a first upper arm, a first forearm, and a first end effector; providing a second robot arm comprising a second upper arm, a second forearm, and a second end effector; connecting a first upper arm to the drive at a first axis of rotation; and connecting the second upper arm to the drive at a second axis of rotation spaced from the first axis of rotation, wherein the first and second robot arms are configured to position the end effector in a first retracted position for at least partially stacking substrates located on the end effector one on top of the other, wherein the first and second robot arms are configured to be rotated to extend the end effector from the first retracted position in a first direction along parallel first paths at least partially one directly above the other, and wherein the first and second robot arms are configured to be rotated to extend the end effector in at least one second direction along second paths spaced from each other that are not one directly above the other, wherein the drive includes only three for rotating the first and second robot arms to extend the end effector and for rotating the first and second robot arms about a third axis of rotation spaced from the first and second axis of rotation A motor.

According to another aspect, the method comprises wherein the first robot arm is provided with a first upper arm and a first forearm having different effective lengths, and wherein the second robot arm is provided with a second upper arm and a second forearm having different effective lengths.

In accordance with another aspect, the method includes at least one non-circular pulley at the first axis of rotation and a first belt connecting the drive to the first forearm at a first joint between the first upper arm and the first forearm.

In accordance with another aspect, a method includes a first circular pulley and a first belt connecting a drive to a second circular pulley at a first joint between a first upper arm and a first forearm, where the first and second pulleys have different diameters.

According to another aspect, the method includes connecting a controller to the drive, the controller configured to control the drive to move the first and second robot arms substantially simultaneously along the first path from the first retracted positions and to move the first and second arms separately or simultaneously along the second path.

In accordance with another aspect, an apparatus comprises: a first robotic arm comprising a first upper arm, a first forearm, and a first end effector; a second robot arm comprising a second upper arm, a second forearm, and a second end effector; and a drive connected to the first and second robot arms, wherein the first upper arm is connected to the drive at a first axis of rotation, wherein the second upper arm is connected to the drive at a second axis of rotation spaced from the first axis of rotation, wherein the drive comprises five motors for rotating the first and second upper arms, wherein a first one of the motors is connected to the first and second robot arms to rotate the first and second arms about a third axis of rotation spaced from the first and second axis of rotation, wherein a second and third one of the motors is connected to the first robot arm to rotate the first upper arm and the first forearm, respectively, and wherein a fourth and fifth one of the motors is connected to the second robot arm to rotate the second forearm and the first robot arm, respectively, independently, wherein the first and second robot arms are configured to position the end effector in a first effector withdrawn position for use in positioning the end effector in a first effector withdrawn position for at least part of a substrate located thereon Stacked one on top of the other, wherein the first and second robot arms are configured to extend the end effector from the first retracted position in a first direction along parallel first paths that are at least partially directly above one another, and wherein the first and second robot arms are configured to extend the end effector in at least one second direction along spaced second paths that are not directly above one another.

In accordance with another aspect, a method comprises: positioning respective first and second end effectors of first and second robot arms in first retracted positions for stacking substrates located on the end effectors at least partially one on top of the other, wherein the first robot arm comprises a first upper arm, a first forearm, and a first end effector, wherein the first upper arm is connected to a drive at a first axis of rotation, and wherein the second robot arm comprises a second upper arm, a second forearm, and a second end effector, wherein the second upper arm is connected to the drive at a second axis of rotation spaced from the first axis of rotation; moving the first and second robot arms to move the end effector from the first retracted position in a first direction along parallel first paths at least partially directly above one another; moving the first and second robot arms to move the end effector to extend the end effector in at least one second direction along a second path spaced from one another that is not one above the other; rotating the first and second robot arms together about a third axis of rotation spaced from the first and second axes of rotation, wherein movement in the first direction from the first retracted position, movement and rotation to extend the end effector in at least one second direction utilizes five motors of the drive, wherein a first of the motors is connected to the first and second robot arms to rotate the first and second arms about the third axis of rotation, wherein a second and third of the motors is connected to the first robot arm to rotate the first upper arm and the first forearm, respectively, and wherein a fourth and fifth of the motors is connected to the second robot arm to rotate the second upper arm and the second forearm, respectively, independently of the first robot arm.

In accordance with another aspect, a method or apparatus includes wherein the first motor is aligned on a third axis, the second and third motors are aligned with each other on the first axis, and the fourth and fifth motors are aligned with each other on the second axis.

In accordance with another aspect, a method comprises: providing a first robotic arm comprising a first upper arm, a first forearm, and a first end effector; providing a second robot arm comprising a second upper arm, a second forearm, and a second end effector; connecting a first upper arm to the drive at a first axis of rotation; and connecting the second upper arm to the drive at a second axis of rotation spaced from the first axis of rotation, wherein the first and second robot arms are configured to position the end effector in a first retracted position for at least partially stacking substrates located on the end effector one on top of the other, wherein the first and second robot arms are configured to be rotated to extend the end effector from the first retracted position in a first direction along parallel first paths at least partially located one directly above the other, and wherein the first and second robot arms are configured to be rotated to extend the end effector in at least one second direction along second paths spaced from each other that are not located one above the other, wherein the drive includes five axes of rotation for rotating the first and second robot arms to extend the end effector and for rotating the first and second robot arms about a third axis of rotation spaced from the first and second axes of rotation A motor, wherein a first of the motors is connected to the first and second robot arms to rotate the first and second arms about a third axis of rotation, wherein a second and third of the motors are connected to the first robot arm to rotate the first upper arm and the first forearm, respectively, and wherein a fourth and fifth of the robot arms are connected to the second robot arm to rotate the second upper arm and the second forearm, respectively, independently of the first robot arm.

In accordance with another aspect, an apparatus comprises: a first robotic arm comprising a first upper arm, a first forearm, and a first end effector; a second robot arm comprising a second upper arm, a second forearm, and a second end effector; and a drive connected to the first and second robot arms, wherein the first upper arm is connected to the drive at a first axis of rotation, wherein the second upper arm is connected to the drive at a second axis of rotation spaced from the first axis of rotation, wherein the drive comprises four motors for rotating the first and second upper arms, wherein a first one of the motors is connected to the first upper arm, wherein a second one of the motors is connected to the second upper arm, wherein a third one of the motors is connected to the first forearm, wherein a fourth one of the motors is connected to the second forearm, wherein the third and fourth motors are aligned on a common axis spaced from the first and second axes, wherein the first motor is aligned on the first axis and wherein the second motor is aligned on the second axis, wherein the first and second robot arms are configured to position the end effector in a first retracted position for at least partially stacking substrates located on the end effector one on top of the other, wherein the first and second robot arms are configured to extend the end effector from the first retracted position in a first direction along parallel first paths that are at least partially directly above one another, and wherein the first and second robot arms are configured to extend the end effector in at least one second direction along spaced second paths that are not directly above one another.

In one example embodiment, an apparatus is provided that includes at least one processor; and at least one non-transitory memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to: positioning respective first and second end effectors of first and second robot arms in first retracted positions for stacking substrates located on the end effectors at least partially one on top of the other, wherein the first robot arm comprises a first upper arm, a first forearm, and a first end effector, wherein the first upper arm is connected to a drive at a first axis of rotation, and wherein the second robot arm comprises a second upper arm, a second forearm, and a second end effector, wherein the second upper arm is connected to the drive at a second axis of rotation spaced from the first axis of rotation; moving the first and second robot arms to move the end effector from the first retracted position in a first direction along parallel first paths at least partially directly above one another; moving the first and second robot arms to move the end effector to extend the end effector in at least one second direction along a second path spaced from one another that is not one above the other; rotating the first and second robot arms together about a third axis of rotation spaced from the first and second axes of rotation, wherein movement in the first direction from the first retracted position, movement and rotation extending the end effector in at least one second direction utilizes only three motors of the drive.

In accordance with an example embodiment, there is provided an apparatus comprising a machine-readable non-transitory program storage device, the transitory program storage device tangibly embodying a program of instructions executable by the machine for performing operations, the operations comprising: positioning respective first and second end effectors of first and second robot arms in first retracted positions for stacking substrates located on the end effectors at least partially one on top of the other, wherein the first robot arm comprises a first upper arm, a first forearm, and a first end effector, wherein the first upper arm is connected to a drive at a first axis of rotation, and wherein the second robot arm comprises a second upper arm, a second forearm, and a second end effector, wherein the second upper arm is connected to the drive at a second axis of rotation spaced from the first axis of rotation; moving the first and second robot arms to move the end effector from the first retracted position in a first direction along parallel first paths at least partially directly above one another; moving the first and second robot arms to move the end effector to extend the end effector in at least one second direction along a second path spaced from one another that is not one above the other; rotating the first and second robot arms together about a third axis of rotation spaced from the first and second axes of rotation, wherein movement in the first direction from the first retracted position, movement and rotation extending the end effector in at least one second direction utilizes only three motors of the drive.

In one example embodiment, an apparatus is provided that includes at least one processor; and at least one non-transitory memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to: positioning respective first and second end effectors of first and second robot arms in first retracted positions for stacking substrates located on the end effectors at least partially one on top of the other, wherein the first robot arm comprises a first upper arm, a first forearm, and a first end effector, wherein the first upper arm is connected to a drive at a first axis of rotation, and wherein the second robot arm comprises a second upper arm, a second forearm, and a second end effector, wherein the second upper arm is connected to the drive at a second axis of rotation spaced from the first axis of rotation; moving the first and second robot arms to move the end effector from the first retracted position in a first direction along parallel first paths at least partially directly above one another; moving the first and second robot arms to move the end effector to extend the end effector in at least one second direction along a second path spaced from one another that is not one above the other; rotating the first and second robot arms together about a third axis of rotation spaced from the first and second axes of rotation, wherein movement in the first direction from the first retracted position, movement and rotation to extend the end effector in at least one second direction utilizes five motors of the drive, wherein a first of the motors is connected to the first and second robot arms to rotate the first and second arms about the third axis of rotation, wherein a second and third of the motors is connected to the first robot arm to rotate the first upper arm and the first forearm, respectively, and wherein a fourth and fifth of the robot arms are connected to the second robot arm to rotate the second upper arm and the second forearm, respectively, independently of the first robot arm.

In accordance with an example embodiment, there is provided an apparatus comprising a machine-readable non-transitory program storage device tangibly embodying a program of instructions executable by the machine for performing operations, the operations comprising: positioning respective first and second end effectors of first and second robot arms in first retracted positions for stacking substrates located on the end effectors at least partially one on top of the other, wherein the first robot arm comprises a first upper arm, a first forearm, and a first end effector, wherein the first upper arm is connected to a drive at a first axis of rotation, and wherein the second robot arm comprises a second upper arm, a second forearm, and a second end effector, wherein the second upper arm is connected to the drive at a second axis of rotation spaced from the first axis of rotation; moving the first and second robot arms to move the end effector from the first retracted position in a first direction along parallel first paths at least partially directly above one another; moving the first and second robot arms to move the end effector to extend the end effector in at least one second direction along a second path spaced from one another that is not one above the other; rotating the first and second robot arms together about a third axis of rotation spaced from the first and second axes of rotation, wherein movement in the first direction from the first retracted position, movement and rotation to extend the end effector in at least one second direction utilizes five motors of the drive, wherein a first of the motors is connected to the first and second robot arms to rotate the first and second arms about the third axis of rotation, wherein a second and third of the motors is connected to the first robot arm to rotate the first upper arm and the first forearm, respectively, and wherein a fourth and fifth of the robot arms are connected to the second robot arm to rotate the second upper arm and the second forearm, respectively, independently of the first robot arm.

Any combination of one or more computer-readable media may be utilized as memory. The computer readable medium may be a computer readable signal medium or a non-transitory computer readable storage medium. A non-transitory computer readable storage medium does not include a propagated signal and may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

It should be appreciated that the foregoing description is merely illustrative. Various alternatives and modifications can be devised by those skilled in the art. Accordingly, the present embodiments are intended to embrace all such alternatives, modifications and variances. For example, the features recited in the various dependent claims may be combined with each other in any suitable combination. In addition, features from different embodiments described above may be selectively combined into new embodiments. Accordingly, the present description is intended to embrace all such alternatives, modifications and variances which fall within the scope of the appended claims.

Claims

1. A transport apparatus comprising:

a first robotic arm comprising a first upper arm, a first forearm, and a first end effector;

a second robot arm comprising a second upper arm, a second forearm, and a second end effector; and

a drive connected to the first and second robot arms, wherein the first upper arm is connected to the drive at a first axis of rotation, wherein the second upper arm is connected to the drive at a second axis of rotation spaced from the first axis of rotation, wherein the drive includes only three motors for rotating the first and second upper arms,

wherein the first and second robot arms are configured to position the end effector in a first retracted position for at least partially stacking substrates located on the end effector one on top of the other, wherein the first and second robot arms are configured to extend the end effector in a first direction from the first retracted position along parallel first paths that are at least partially directly above the other, and wherein the first and second robot arms are configured to extend the end effector in at least one second direction along spaced second paths that are not directly above the other;

wherein the first upper arm and the first forearm have different effective lengths, and wherein the second upper arm and the second forearm have different effective lengths.

2. An apparatus as in claim 1 further comprising at least one non-circular pulley and a first band connecting the drive to the first forearm at a first joint between the first upper arm and the first forearm.

3. The apparatus of claim 1 or 2, further comprising a second strap connecting the first end effector to the first joint at a wrist joint of the first end effector to the first forearm.

4. The apparatus of claim 1 or 2, wherein the first and second end effectors each have a generally L-shape.

5. An apparatus as in claim 1 further comprising a first circular pulley and a first belt connecting the drive to a second circular pulley at a first joint between the first upper arm and the first forearm, wherein the first and second pulleys have different diameters.

6. The apparatus of any of claims 1-2 and 5, wherein the first path is along a straight line from the first retracted position.

7. The apparatus of any of claims 1-2 and 5, wherein the first and second robot arms are configured to provide a second retracted position to position the end effector such that the substrates located on the end effector are not stacked one on top of the other.

8. The apparatus of any of claims 1-2 and 5, further comprising a controller configured to control the drive to move the first and second robot arms substantially simultaneously along the first path from the first retracted positions and to move the first and second robot arms individually or simultaneously along the second path.

9. The apparatus of any of claims 1-2 and 5, wherein the three motors are aligned on a common axis.

10. The apparatus of any of claims 1-2 and 5, wherein the three motors are located on three respective spaced axes.

11. The apparatus of any of claims 1-2 and 5, further comprising a z-axis motor connected to the drive to move the drive and the first and second robot arms vertically.

12. A method of shipping, comprising:

positioning respective first and second end effectors of first and second robot arms in first retracted positions for stacking substrates located on the end effectors at least partially one on another, wherein the first robot arm comprises a first upper arm, a first forearm, and the first end effector, wherein the first upper arm is connected to a drive at a first axis of rotation, and wherein the second robot arm comprises a second upper arm, a second forearm, and the second end effector, wherein the second upper arm is connected to the drive at a second axis of rotation spaced apart from the first axis of rotation, wherein the first upper arm and the first forearm have different effective lengths, and wherein the second upper arm and the second forearm have different effective lengths;

moving the first and second robot arms to move the end effector from the first retracted position in a first direction along parallel first paths at least partially directly above one another;

moving the first and second robot arms to move the end effector to extend the end effector in at least one second direction along a second path spaced from one another that is not one above the other;

rotating the first and second robot arms together about a third axis of rotation spaced from the first and second axes of rotation,

wherein movement in the first direction from the first retracted position, movement to extend the end effector in the at least one second direction, and the rotation utilize only three motors of the driver.

13. A method as in claim 12, wherein moving the first and second robot arms comprises at least one non-circular pulley and a first belt connecting the drive to the first forearm at a first joint between the first upper arm and the first forearm.

14. The method of claim 12 or 13, wherein moving the first and second robot arms comprises connecting the first end effector to a second band of the first joint at a wrist joint of the first end effector to the first forearm.

15. A method as in claim 12, wherein moving the first and second robot arms comprises a first circular pulley and a first belt connecting the drive to a second circular pulley at a first joint between the first upper arm and the first forearm, wherein the first and second pulleys have different diameters.

16. The method of any one of claims 12, 13 and 15, further comprising a controller controlling motors of the drives to move the first and second robot arms substantially simultaneously along the first path from the first retracted positions and to move the first and second robot arms individually or simultaneously along the second path.

17. A method for manufacturing a transport apparatus, comprising:

providing a first robotic arm comprising a first upper arm, a first forearm, and a first end effector;

providing a second robot arm comprising a second upper arm, a second forearm, and a second end effector;

connecting the first upper arm to a drive at a first axis of rotation; and

connecting the second upper arm to the drive at a second axis of rotation spaced from the first axis of rotation,

wherein the first and second robot arms are configured to position the end effectors in first retracted positions for at least partially stacking substrates located on the end effectors one on top of the other, wherein the first and second robot arms are configured to rotate to extend the end effectors from the first retracted positions in a first direction along parallel first paths that are at least partially directly above the other, and wherein the first and second robot arms are configured to rotate to extend the end effectors in at least one second direction along second paths that are spaced apart from each other that are not located one above the other,

wherein the drive includes only three motors for rotating the first and second robot arms to extend the end effector and for rotating the first and second robot arms about a third axis of rotation spaced from the first and second axes of rotation;

wherein the first robot arm is provided with the first upper arm and the first forearm having different effective lengths, and wherein the second robot arm is provided with the second upper arm and the second forearm having different effective lengths.

18. A method as in claim 17 further comprising at least one non-circular pulley at the first axis of rotation and a first band connecting the drive to the first forearm at a first joint between the first upper arm and the first forearm.

19. The method of claim 17 or 18, further comprising a second strap connecting the first end effector to the first joint at a wrist joint of the first end effector to the first forearm.

20. A method as in claim 17, further comprising a first circular pulley and a first belt connecting the drive to a second circular pulley at a first joint between the first upper arm and the first forearm, wherein the first and second pulleys have different diameters.

21. A method as in any one of claims 17, 18 and 20, wherein the first and second robot arms are configured to provide the first path along a straight line from the first retracted position.

22. The method of any of claims 17, 18, and 20, further comprising wherein the first and second robot arms are configured to provide a second retracted position to position the end effector such that the substrates located on the end effector are not stacked one on top of the other.

23. A method as in any one of claims 17, 18 and 20, further comprising connecting a controller to the drive, the controller configured to control the drive to move the first and second robot arms substantially simultaneously along the first path from the first retracted positions and to move the first and second robot arms individually or simultaneously along the second path.

24. A transport apparatus comprising:

a drive connected to the first and second robot arms, wherein the first upper arm is connected to the drive at a first axis of rotation, wherein the second upper arm is connected to the drive at a second axis of rotation spaced from the first axis of rotation, wherein the drive includes five motors for rotating the first and second upper arms, wherein a first one of the motors is connected to the first and second robot arms to rotate the first and second robot arms about a third axis of rotation spaced from the first and second axis of rotation, wherein second and third ones of the motors are connected to the first robot arm to rotate the first upper arm and the first forearm, respectively, and wherein fourth and fifth ones of the motors are connected to the second robot arm to rotate the second upper arm and the second forearm, respectively, independently of the first robot arm,

wherein the first and second robot arms are configured to position the end effector in the first retracted position for at least partially stacking substrates located on the end effector one on top of the other, wherein the first and second robot arms are configured to extend the end effector from the first retracted position in a first direction along parallel first paths that are at least partially directly above the other, and wherein the first and second robot arms are configured to extend the end effector in at least one second direction along second paths that are not spaced apart from each other;

25. An apparatus as in claim 24 further comprising at least one non-circular pulley and a first band connecting the drive to the first forearm at a first joint between the first upper arm and the first forearm.

26. The apparatus of claim 24 or 25, further comprising a second strap connecting the first end effector to the first joint at a wrist joint of the first end effector to the first forearm.

27. The apparatus of claim 24 or 25, wherein the first and second end effectors each have a generally L-shape.

28. An apparatus as in claim 24 further comprising a first circular pulley and a first belt connecting the drive to a second circular pulley at a first joint between the first upper arm and the first forearm, wherein the first and second pulleys have different diameters.

29. The apparatus of any one of claims 24, 25 and 28, wherein the first path is along a straight line from the first retracted position.

30. The apparatus of any one of claims 24, 25 and 28, wherein the first and second robot arms are configured to provide a second retracted position to position the end effector such that the substrates located on the end effector are not stacked one on top of the other.

31. An apparatus as in any one of claims 24, 25 and 28, further comprising a controller configured to control the drive to move the first and second robot arms substantially simultaneously along the first path from the first retracted positions and to move the first and second robot arms individually or simultaneously along the second path.

32. The apparatus of any one of claims 24, 25 and 28, further comprising a z-axis motor connected to the drive to move the drive and the first and second robot arms vertically.

33. A method of shipping, comprising:

wherein movement in the first direction from the first retracted position, movement to extend the end effector in the at least one second direction, and the rotation utilize five motors of the drive, wherein a first of the motors is connected to the first and second robot arms to rotate the first and second robot arms about the third axis of rotation, wherein second and third of the motors are connected to the first robot arm to rotate the first upper arm and the first forearm, respectively, and wherein fourth and fifth of the robot arms are connected to the second robot arm to rotate the second upper arm and the second forearm, respectively, independently of the first robot arm.

34. The method of claim 33, wherein the first motor is aligned on the third axis of rotation, the second and third motors are aligned with each other on the first axis of rotation, and the fourth and fifth motors are aligned with each other on the second axis of rotation.

35. A method for manufacturing a transport apparatus, comprising:

connecting the first upper arm to a drive at a first axis of rotation; and

wherein the first and second robot arms are configured to position the end effectors in first retracted positions for at least partially stacking substrates located on the end effectors one on top of the other, wherein the first and second robot arms are configured to rotate to extend the end effectors from the first retracted positions in a first direction along parallel first paths that are at least partially directly above the other, and wherein the first and second robot arms are configured to rotate to extend the end effectors in at least one second direction along spaced second paths that are not located above the other,

wherein the drive includes five motors for rotating the first and second robot arms to extend the end effector and for rotating the first and second robot arms about a third axis of rotation spaced from the first and second axes of rotation,

wherein a first one of the motors is connected to the first and second robot arms to rotate the first and second robot arms about the third axis of rotation, wherein second and third ones of the motors are connected to the first robot arm to rotate the first upper arm and the first forearm, respectively, and wherein fourth and fifth ones of the robot arms are connected to the second robot arm to rotate the second upper arm and the second forearm, respectively, independently of the first robot arm;

36. A transport apparatus comprising:

a drive connected to the first and second robot arms, wherein the first upper arm is connected to the drive at a first axis of rotation, wherein the second upper arm is connected to the drive at a second axis of rotation spaced from the first axis of rotation, wherein the drive comprises four motors for rotating the first and second upper arms, wherein a first of the motors is connected to the first upper arm, wherein a second of the motors is connected to the second upper arm, wherein a third of the motors is connected to the first forearm, wherein a fourth of the motors is connected to the second forearm, wherein third and fourth motors are aligned on a common axis spaced from the first and second axes of rotation, wherein a first motor is aligned on the first axis of rotation and wherein a second motor is aligned on the second axis of rotation,