US3318468A

US3318468A - Vacuum type load handling mechanism

Info

Publication number: US3318468A
Application number: US390538A
Authority: US
Inventors: John E Olson
Original assignee: Hyster Co
Current assignee: Hyster Co
Priority date: 1964-08-19
Filing date: 1964-08-19
Publication date: 1967-05-09
Anticipated expiration: 1984-05-09

Description

y 1967 J. E. OLSON 3,318,468

'VACUUM TYPE LOAD HANDLING MECHANISM Filed Aug. 19, 1964 4 Sheets-Sheet 1 JOHN E. OLSON lNl/E/VTO/i BUC/(HOR/V, BLO/PE, KLA/mu/sr a SPAR/(MAN ATTORNEYS May 9, 1967 J. E. OLSON 3,318,453

VACUUM TYPE LOAD HANDLING MECHANISM Filed Aug. 19, 1964 4 Sheets-Sheet 2 w/aw F l g. 9

BUG/(HORN, 51.095, KLA/FOU/ST a SPAR/(MAN Arrofi/vfim 1957 J, E. OLSON 3,318,468

VACUUM TYPE LOAD HANDLING MECHANISM Filed Aug. 19, 1964 4 Sheets-Sheet 5 P Fig. 11/

JOHN E- OLSON I/Vl/ENTO/P BY BUC/(HO/F/V, BL ORE, KLAROU/ST a SPAR/(MAN ATTORNEYS United States Patent 3,318,468 VACUUM TYPE LOAD HANDLING MECHANlSM John E. Olson, Portland, 0reg., assignor to Hyster Company, Portland, 0reg., a corporation of Nevada Filed Aug. 19, 1964, Ser. No. 390,538 19 Claims. (Cl. 214-650) This invention relates to a vacuum type load handling mechanism or apparatus and particularly one utilizing a bellows as a primary element in a lifting mechanism or apparatus such as on a lift truck.

In lifting an article by means of a bellows, particularly a heavy article such as a paper roll, I have discovered that an unstable condition exists. It occurs because the differential pressure force acting on the bottom surfaces of the roll to lift it acts through the roll against the lower end of the bellows. The usual bellows is inherently unstable in a lateral direction and hence the roll will force the lower end thereof laterally and assume a tilted condition, which is objectionable for obvious reasons.

A main object of the present invention is to provide a bellows type load pick-up arrangement having stabilizing means which stabilize the lower part of the bellows against lateral displacement without interfering with the extension or collapse of the bellows.

A further object is to provide a pick-up arrangement as just described which does not impart any rotary movements to the ends of the bellows and in fact precludes rotary movement between such ends.

A further object is to provide a pick-up arrangement which will decrease the load handling time.

With a bellows system, if, at load pick-up time, the interior of the bellows were at atmospheric pressure, it is apparent that the pressure of the considerable volume of air within the bellows would have to be lowered substantially before the load could be picked up, and this would take time.

Accordingly, another important object of the invention is to provide a bellows type load handling mechanism so constructed that the interior of the bellows is at subatmospheric pressure prior to engagement with the load, and wherein the bellows is prohibited from being entirely collapsed so that it forms a vacuum accumulator, and wherein a valving arrangement is provided so that when the bellows engages a load, a subatmospheric pressure can immediately be applied to the load by placing the engaged surface of the load in communication with the interior of the bellows so that rapid pick-up is possible.

Another object of the invention is to provide a bellows type load pick-up mechanism in which the load contacting end of the bellows is in the form of a suction head, wherein valving means are provided for controlling the communication of this suction head with the interior of the bellows and wherein the pressure at the suction head can be rapidly elevated from a subatmospheric value to atmospheric pressure without having to raise the pressure within the bellows.

A further object of the invention is to provide a bellows type load pick-up mechanism having a valving arrangement permitting the bellows to be used for actually lifting and lowering the load, as well as supporting the load during transport.

Another object of the invention is to provide a bellows type load pick-up mechanism without a source of vacuum but with a mechanism for raising and lowering the bellows in combination with suitable valving means to facilitate raising and lowering a load.

Still another object of the invention is to provide a bellows type load pick-up mechanism having automatic means for maintaining minimal safe vacuum and which has novel shock absorbing abilities and automatic means for maintaining a desired Vacuum despite infiltration of air.

Another object is to provide, in a bellows device, a means for compressing the sealing lip by providing a lesser low pressure area on top of the sealing rim than on the underside of the rim.

A further object is to provide a means of supplementing the travel distance of a lift truck carriage by providing a bellows that will lift the load a considerable distance without requiring the carriage to be raised.

Various other objects of the invention will be apparent from the following description taken in connection with the accompanying drawings wherein:

FIG. 1 is a perspective view of a lift truck incorporating a bellows type load handling apparatus of the present invention, showing the same in position above a heavy paper roll prior to lowering the bellows into contact with the roll for picking up the same;

FIG. 2 shows the load raised for transportation or stacking;

FIG. 3 shows bellows extended under an emergency condition wherein air infiltration exceeds pump capacity or wherein the truck has traversed a bump that induces a dynamic load on the bellows;

FIG. 4 is an enlarged side elevational view of the apparatus showing the bellows assembly suspended from the load carriage with the bellows proper in its extended condition;

FIG. 5 is a midsectional view through the bellows assembly taken along lines 5-5 of FIG. 8, with the section being taken through the bellows proper but not through the internal mechanism;

FIG. 6 is an enlarged sectional view of the portion of FIG. 5 indicated by the line 6fi;

FIG. 7 is an enlarged sectional view of the portion of FIG. 5 indicated by the line 77;

FIG. 8 is a plan view of the bellows assembly taken along line 88 of FIG. 4;

FIG. 8A is an enlarged fragmentary sectional view taken along line 8A8A of FIG. 5;

FIG. 9 is a bottom view of the bellows assembly taken in the direction of the arrows 99 of FIG. 4; 7

FIG. 10 is a diagrammatic view showing certain essential parts of the bellows stabilizing mechanism;

FIGS. 11 and 12 are diagrammatic views indicating the forces tending to set up the unstabilized condition in the bellows;

FIG. 13 is a diagrammatic view showing certain of the valving and control arrangements associated with the bellows;

FIG. 13A shows an alternate embodiment including an automatic valve;

FIG. 14 shows a modified form of the invention;

FIG. 15 is a view similar to FIG. 14 but showing the load being lifted;

FIG. 16 is a diagrammatic view of the bellows assembly having a counterpoise valve means;

FIG. 17 shows a further modified form of the invention prior to engagement of the bellows assembly with the load;

FIGS. 18 and 19 show subsequent steps in picking up the load;

Referring to the accompanying drawings, and particularly to FIGS. 1, 2 and 3, the lift truck 11 has a vertically extensible mast M at the front end thereof which includes stationary uprights 13 and movable uprights 15 which are extended by hydraulic ram 17 or equivalent elevating mechanism. The elevating mechanism lifts a load carriage, generally entitled C, by any conventional means such as, for instance, lift chains 19. The carriage has a forwardly projecting support member 21 pivotally connected to a pair of ears 23 which are secured to an end plate 25 of a bellows B. In some cases it is expedient to fasten the end plate rigidly to the support member 21.

Vacuum is supplied to the bellows B by means of a vacuum pump P on the body of the truck (and/ or other source on the truck), there being a conduit extending from the pump to the bellows. A part of the conduit is shown in FIG. 1 and indicated by reference numeral 27 and is in the form of an extensible, contractible, flexible conduit. It may, for instance, be of bellows-like form itself. A take-up mechanism for the conduit 27 of conventional form may be provided.

A control box 31, to be described, is mounted on end plate 25 (FIG. 4). This is shown in phantom at 31' in FIG. 13. An opening to ambient pressure is provided at 40.

Referring to FIG. 5, the lower end of the bellows is closed by an end plate 32 which is provided with a circular sealing means or lip 33, so that the end plate and sealing means form a suction head 34 at the lower portion of the bellows.

As shown in FIG. 4, the suction head 34 is of larger diameter than the bellows and hence a differential pressure force is created at load pick-up time to press the suction head against the load regardless of the low pressure that might exist inside the bellows.

Referring only briefly to FIG. 9, the lower plate 32 has a central sealing member 37 to surround the opening (FIG. 1) in the center of the load, if said load is a roll of paper as illustrated. Any other openings in the load may be similarly covered.

General operation While the invention will be described in connection with picking up a heavy roll of paper, and while the bellows is especially formed for this purpose, it is specifically pointed out that the invention is not intended to be limited to picking up paper rolls, and the bellows in the form shown (and having the same or other sealing means) can be used to pick up many different types of loads.

FIG. 1 shows the truck approaching a heavy roll of paper R. It should be noted that full collapse or contraction of the bellows is prevented as will be described later so that the bellows can act as a vacuum accumulator.

When the suction head 34 of the bellows is brought into engagement with the top of a load by lowering the carriage C, the operator opens a valve associated therewith to place the suction head in communication with the interior of the bellows. Thus, subatmospheric pressure is immediately applied against the top of the roll permitting immediate elevation of the carriage to pick up the roll without delay.

When handling a short roll, the operator may allow the bellows to extend so the suction cup 34 can reach it. On evacuating the bellows the roll is raised to the collapsed bellows position. Thus, it is possible to mount the bellows high on the carriage of the lift truck so it can stack to a maximum height.

Detailed description During operation, the round or circular cross sectional shape of the bellows is maintained by rigid rings 38 (FIG. 6) disposed within the bellows proper and located at the convex portions of the convolutions of the bellows. These rings may be encased in extrusions such as 39 (FIG. 6) which are cemented to the bellows. Elastic rings or coil springs 38a (FIGS- and 6) are placed around the exterior of the bellows in the concave portions of the convolutions to cause the bellows to fold properly as the bellows is contracted or extended.

Referring to FIGS. 11 and 12, the bellows B is shown diagrammatically as is the roll R. FIG. 11 shows the roll the instant it leaves the floor F and FIG. l2 shows 4 n it as it might be shortly thereafter if not provided wit lateral support at the top. The arrows A indicate the differential pressure forces acting on the underside of the roll. It should be pointed out that it is not the bellows B which lifts the roll, but the differential pressure force acting on the lower end of the roll which does the lifting.

Because of this, an unstable condition is established be cause the center of gravity G of the roll is above the center of support. This unstable condition can be most readily appreciated if it is assumed that the load is rest ing on a large balloon which is resting on the floor. Obviously, the load would tend to fall over under this condition so it must be stabilized bylateral support at the top. It is clear, therefore, that some means must be provided for maintaining the top of the roll generally in alignment with its center of gravity. The purpose of the stabilizing mechanism of the present invention is to provide the necessary lateral support.

The stabilizing mechanism includes two sets of links, an

upper set

41a, 41b and 410, and a

lower set

43a, 43b and 430. Between the sets of links is a connecting plate 45, the shape of which is shown in FIGS. 8 and 10 as being somewhat irregular, but this is occasioned only because of design desirability in one form of the invention constructed. The connection plate is suspended from the end plate 25 by cables 47 and is connected to the lower end plate 32 by cables 49. The length of the cables associated with each set of links is less than that of thelinks so that the links are arranged in inclined positions be tween the connection plate and the

end plates

25 and 32. Each of the links 41a, 41b and 41c has its upper end connected by a universal joint J to the upper end plate 25, and has its lower end connected by a similar joint to the connecting plate 45. The

links

43a, 43b and 430 are similarly connected between the connection plate a 45 and end plate 32. Each of the joints on the plate 25- is equally spaced from the other two joints, as is apparent from FIG. 8, and the same is true of joints on

plates

45 and 32. Fro-m a plan view, each set of links forms an equilateral triangle as is evident from FIG. 8. It appears from FIG. 8 that each link has its ends connected to certain ends of other of the links but this is only an illusion. The illusion is caused by the fact that'in FIG. 8 the joints I on the upper plate 25 are in superimposed relation with respect to the joints J on the

plates

45 and 32.

When the bellows collapses, the links assume more nearly horizontal positions, and the only way they can assume such positions is by rotation of the connecting" plate 45 about the axis of the bellows and this is permitted. However, the lower set of links is' disposed 'in V a subtractive rather than cumulative position relative to the upper set of links so that looking from the lower end of the bellows, the links 43a, 43b and 43c are tending to rotate the plate 45 in the same direction as the links 41a, 41b and 41c are tending to rotate the plate. Thus, while the plate 45 turns or rotates, the

plates

25 and 32 have no relative rotation, and thus there is no tendency,- when engaging a load, for the sealing means to be rubbed against the load (and hence cause wear) because of rotative movement of the lower plate. Also when the load is lifted and the bellows extends somewhat, there is no rotation of the plate 32 with respect to plate 25 which might tend to destroy the bellows. I

Referring to FIGS. 5 and 8A, each joint includes an upright stud shaft 51 aschored to the associated plate. A pivot block 53 is rotatably journaled on each stud shaft and secured in place by a snap ring 54. Each end of each link 41, 43, is affixed to a yoke 55, the arms of which straddle opposite sides of the associated block 53. and are pivoted thereto by pivot pins 57. Thus, each link has a universal pivoting action that enables it to move around the stud shaft and also permits variations in the angular relationship of the link and stud shaft. 'Since 'two stud shafts '51 will be on opposite sides of the con- I in a contracted condition.

necting plate 45, and in alignment with one another, a single shaft projecting through the connecting plate and secured thereto can provide two studs.

As the bellows collapses, the stud shafts 51 on one plate will approach an adjacent plate and upon abutment therewith will limit the collapse of the bellows to provide an accumulator. This accumulator encompasses a chamber at subatmospheric pressure which will rapidly draw air from the vacuum head when a valve, to be described later, is opened. It will be noted that this volume, as shown by the drawings, is considerably larger than the volume within the suction cup 34 so after the pressure in the cup and that in the chamber is equalized, alow pressure will be obtained in both cavities. Certain conditions may require it to be greater or less than shown but these conditions may be met by using longer or shorter studs.

Referring now to FIGS. 5 and 9, the suction head 34 has a reticulated structure 61 secured to the lower face thereof. The reticulated structure may be in the form of expanded metal or a heavy screen to provide for the ready distribution of air to and from all parts of the suction head. The suction head is also equipped with four load contacting pads 63, which preferably are in the form of rubber or elastomer coated plates in which the load contacting surface is serrated in opposite directions.

Referring now to FIG. 5, a flexible conduit 67 extends from the control box 31 to a fitting 69 on the connecting plate 45, and a flexible conduit 71 extends from the fitting 69 to a fitting 73 shown in FIG. 9. There is a valve in the control box (not specifically shown) which is equipped with a solenoid and can be operated through the medium of electrical conductors extending to the controls on the body of the truck to place the conduit 67 and thus the suction head in communication with the ambient air without afiecting the pressure of the air within the bellows B.

FIG. 13 shows the control system in which the pump P communicates with the bellows B through a conduit 27', chamber 95 and port 96 in end plate 25. The chamber 95 is provided on the upper end plate 25 and communicates with an accumulator 97 through a check valve 99. Another valve in the chamber 95 includes a poppet 101 movable between a seat 103 and a seat 105. When the poppet 101 is against seat 105 and the port at 103 is open, suction head 34' is placed in communication with the pump. The interior of the bellows B is always in communication with the pump P through port 96. The movement of poppet 101 is controlled by a vacuum actuator 108. The actuator is connected by a conduit 109 with a valve 111 controlled by a solenoid 112. The valve is connected by conduit 113 to the accumulator 97 so there will always be rapid action of the actuator.

The end plate 25 has a valve 115 controlled by vacuum actuator 117 which is connected by conduit 119 to a valve 121. This valve is controlled by solenoid 123. A conduit 125 connects valve 121 to the accumulator 97. A battery 131 supplies energy to the

solenoids

112 and 123 through

switches

135 and 137 which may be located at the operator station.

Operation of FIG. 13 form It may be assumed that the bellows B is under subatmospheric pressure and that valve poppet 101 is in the position shown in FIG. 13, that is, against the seat 103. Under the circumstances, the bellows would be If it were desirable to lower the vacuum head 34 into engagement with the load other than by lowering the end plate 25, this could be done by opening the valve 115 by closing the switch 135 to allow ingress of ambient air into the bellows so that it would extend. For instance, if the bellows B were supported as shown in FIGS. 14 and where the upper end plate of the bellows was at a constant height, engagement of the load could be effected by lowering the suction head. 7

After the suction head engages the load, the port at 103 can be opened by moving valve poppet 101 against the seat 105. This will put suction head 34' in communication with the pump and with the interior of the bellows so the cup will immediately be placed under low pressure. This will also cause contraction of the bellows, and hence raise the load, as shown in FIG. 15. Port 96 between chamber and the bellows is deliberately made small so as to restrict air flow and prevent the bellows lifting before vacuum head 34' has fully engaged the load.

When it is desired to deposit the load, valve poppet 101 can be moved to seat against the seat 103 so that port is open to ambient air. This will place the suction head at atmospheric pressure Without raising the pressure within the bellows B. Therefore the load will be released. Now, if it is assumed that the surface of the load to be contacted by the bellows is very near the level of the suction head 34' of the bellows, when the bellows is contracted, a subatmospheric pressure may be maintained Within the bellows by cracking or opening the valve only slightly to lower the bellows slightly so that a subatmospheric pressure can be rapidly applied against the load by moving poppet 101 from seat 103 to seat 105 because the bellows will act as an accumulator.

FIG. 13A shows an alternate embodiment wherein an automatic valve is installed to control the flow of air through orifice 73. The valve is held closed by spring 200 until the vacuum cup contacts a load to be picked up, at which point the load presses on foot 201 which raises the valve and allows air within the vacuum cup to be drawn into the bellows, thus reducing the pressure in the vacuum cup. The effect is immediate because of the accumulator effect of the bellows. The embodiment of FIG. 13A is used primarily on multiple head pick-up devices to permit only those heads which engage a load to communicate with the vacuum source. Except for the inclusion of valve 145, the FIG. 13A form is identical to that of FIG. 13, with valve 145 serving only to supplement the control provided by

valves

101 and 115.

Operation of FIGS. 14 and 15 form Referring now to FIGS. 14 and 15, the arrangement shown includes a monorail track 121 which is presumed to be mounted on a ceiling 123, although it could be mounted elsewhere. A carriage 125 is supported on the track and has a chain 127 supporting a bellows assembly. The bellows assembly includes housing 129, which together with an end plate such as 25 constitutes a closure means for the upper end of a bellows 131. This configuration does not have the equivalent of plate 32. The bellows has a sealing strip 133 at the lower end thereof to engage a load. The housing encloses a vacuum pump 137 driven by a motor 139. The motor can be supplied with energy by means of a battery 141 or it can be a selfsufiicient prime mover such as an internal combustion engine, or it can be an electric motor supplied with electrical energy by conductors (not shown). A suitable valve lever 143 is provided to control the communication of the bellows 131 with the ambient air or with the vacuum pump. In fact, a control system like that shown in FIG. 13, including plate 32, could well be incorporated in the structure shown in FIG. 14. In simplified form, the valve lever 143 could be operated to place the interior of the bellows in communication with the ambient air to enable it to be lowered, and then be operated to place the interior of the bellows in communication with the pump to create a subatmospheric pressure within the bellows and hence cause it to contract and raise the load L. FIG. 15 shows the load as having been raised.

FIG. 16 shows a modified form of the invention in which the lower end plate 151 of the bellows 153 has a valve element 155 to seat against the suction conduit 157 to close olf communication of the suction conduit with the interior of the bellows when the bellows has conalso has obvious advantages 7 tracted an extent sufficient to bring the member 155 against the end of the conduit 157. Thus, this feature will automatically limit the vacuum drawn to a value only slightly more than required to lift the load. Similarly,

' the subatmospheric pressure will not drop below the mini- Pins 51' prevent the bellows from closing too far.

FIG. 17 shows a modified form of the invention in which the carriage 125A supports a power-driven winch 173 which has a cable 175 connected to the upper end plate 177 .of the bellows 179. A check valve 181 is provided on the upper end plate of the bellows.

The bellows 179 has a sealing lip 183 for engaging the load L. The check valve 181 opens in a direction away from the interior of the bellows 179 so that when the winch 173 is operated to lower the bellows into engagement with a load, the pressure building up in the bellows (because of the weight of the bellows and its top plate) causes the discharge of air from the interior of the bellows through the check valve 181 to the atmosphere. This is the condition shown in FIG. 18. Thereafter, when the winch is operated to haul in the cable 175, the bellows extends slightly to create a subatmospheric pressure to pick up the load, as in FIG. 19. The check valve, while allowing air to'be discharged from the bellows, will not allow air to enter the bellows unless the control member 185 of the check valve is operated. When this occurs, the air can enter the bellows to enable the load to be released. With this device suspended from a crane, 4000 pound rolls of paper have been lifted without using a pump and without even having a man to control the bellows at the point of pick up.

Instead of a check valve, a manually operated valve could be provided which would be open when engaging a load and thereafter closed for carrying the load and subsequently opened to release the load.

An important feature of the bellows is that it makes it safe to carry a load with a very low factor of safety (say 1.2 instead of the customary 2.0) and yet be sure the load will not be dropped by momentary dynamic forces that result from transportation over rough terrain. For example, a load of 1000 pounds can be safely suspended by a differential pressure force totalling only 1000 pounds, plus 200 pounds to compress the seal. If the truck hits a bump, the load, due to dynamic forces, may exert a momentary dynamic force of 2000 pounds which would cause it to break loose if suspended by an ordinary suction cup. With the bellows, however, the dynamic force will simply extend the bellows and this will automatically and instantaneously increase the vacuum so the load cannot break away. The cushioning effect of this extension in reducing the magnitude of dynamic forces. I find that it is impossible to shake a load off when using the apparatus herein described.

The advantage of using minimum vacuum lies in the fact that many loads (paper rolls in particular) are porous and allow considerable infiltration of air. As the differential pressure increases, the infiltration rate increases but the efiiciency of the pump decreases. Therefore, a given pump will safely handle afar greater load when the bellows is used.

Preferably, the sealing lip, such as the lip 33, is of sufficient resiliency that when the device is dropped upon a .load to be picked up the lip will deform to the load and compress slightly so that upon upward movement of the plate upon which the lip is mounted the lip will self-seal itself to the load. After initial vacuum is drawn within the bellows and cup, the higher pressure acting down on the projecting annular rim 190 will force the sealing lip against the load to prevent leakage between lip and load.

Having described the invention in what is considered to be the preferred embodiment thereof, it is desired that it be understood that the invention is not to be limited other than by the provisions of the following claims.

I claim:

1. In a vacuum type load handling apparatus,

a bellows closed at its opposite ends by end plates,

which end plates are in alignment,

one end plate of said bellows having sealing means for engaging a load,

means for maintaining said plates in alignment despite laterally directed forces being imposed against one while the other is restrained against bodily movement, 7

said means including articulated mechanism within said bellows connecting said plates to one another,

said articulated mechanism including at least three link means each including an upper and lower link connected to each other and to said plates by universal connecting means,

the distance between said plates being less than the length of a link means,

and passage means connecting the interior of said bellows wtih the outer side of said one end plate in wardly of said sealing means.

2. In an apparatus according to claim 1,

a vacuum head at one end of said bellows,

means separating said vacuum head from the interior of said bellows,

means for connecting the interior of said bellows with a source of subatmospheric pressure,

valve means operable to control communication of said vacuum head with the interior of said bellows,

the last-named means including a valve actuating mem ber carried by said one end of said bellows to open vacuum pump means carried by said closure means, 7

motor means carried by said closure meansfor driving said pump,

and means for controlling the communication between the interior of said bellows and the ambient. air whereby by raising the pressure within said bellows the bellows may be extended to lower the lower end thereof into contact with a load, and bylowering the pressure therewithin said bellows may be contracted to pick up a load.

4. In an apparatus according to claim 1,

track means,

means for suspending said bellows from 'said track 7 means with the longitudinal axis of said bellows vertical and for raising and lowering said bellows relative to said track means, i said load-engaging sealing means being at the lower end of said bellows, a closure means for the upper end of said bellows, check valve means carried by said closure means and opening in a direction away from the interior of said bellows so that when said bellows is lowered onto a load and collapses, the air therein will 'be expelled through said check valve means, but when said bellows is elevated, ingress of air into said bellows will being at the lower 9 be precluded so that a subatmospheric pressure will be created therein to pick up said load, and means operable when actuated for admitting air into said bellows to enable release of said load. 5. In an apparatus according to claim 1, track means, means for suspending said bellows from said track means with the longitudinal axis of said bellows vertical and for raisin and lowering said bellows relative to said track means, closure means for the upper end of said bellows, valve means carried by said closure means and operable when open to allow the discharge of air from the interior of said bellows and operable when closed to preclude the ingress of air into said bellows, and means for opening and closing said valve means. 6. Apparatus according to claim 1 including stop means within said bellows on one of said end plates and engageable with the other of said end plates for limiting the contraction of said bellows,

a source of vacuum, conduit means extending into said bellows through said other end plate for placing the interior of said bellows in communication with said source, and closure means on said one end plate in alignment with the open end of said conduit within said bellows for closing off communication of said conduit with the interior of said bellows when said bellows contracts a predetermined amount. 7. In a vacuum type load handling apparatus, a bellows closed at its opposite ends by end plates,

which end plates are in alignment, One end plate of said bellows having sealing means for engaging a load, means for maintaining said plates in alignment despite laterally directed forces being imposed against one while the other is restrained against bodily movement, said means including articulated mechanism within said bellows connecting said plates to one another, said articulated mechanism including at least three articulated link means each including an upper and lower link connected to each other and to said plates by universal connecting means, the distance between said plates being less than the length of a link means, the connections on a plate being equally spaced from one another, and passage means connecting the interior of said bellows with the outer side of said one end plate interiorly of said sealing means. 8. In a vacuum type load handling apparatus, a bellows closed at its opposite ends by end plates,

which end plates are in alignment, one end plate of said bellows having sealing means for engaging a load, means for maintaining said plates in alignment despite laterally directed forces being imposed against one tending to move it out of alignment, said means including articulated mechanism within said bellows connecting said plates to one another, said articulated mechanism including at least three links connected at their opposite ends by universal connections to said plates, the connections on a plate being equally spaced from the others, and vacuum means operatively connected to the interior of said bellows for varying the distance between said plates and also being operatively connected to the outer side of said one plate interiorly of said seal ing means to secure a load to said sealing means. 9. In a vacuum type load handling apparatus, a bellows closed at its opposite ends, a pair of spaced parallel plates for said bellows ar- It) ranged generally at right angles to the longitudinal axis of said bellows,

means for maintaining said plates in alignment despite laterally directed forces being imposed against one while the other is restrained against bodily movement,

said articulated mechanism including at least three links each including upper and lower link sections connected at their opposite ends by universal connections to said plates, and to each other,

the distance between said plates being less than the length of a link,

first connecting means connecting one plate to one end of said bellows,

second connecting means connecting the other plate to the other end of said bellows,

and means for creating a vacuum within said bellows and for providing communication between the interior of said bellows and the outer side of said one plate.

10. In a suction type load pick-up apparatus.

a bellows closed at its opposite ends,

means supporting said bellows with its longitudinal axis vertical,

a vacuum head at the lower end of said bellows for engaging a load,

a source of vacuum communicating with the interior of said bellows,

first valve means for placing the interior of said bellows in communication with the ambient air,

and second valve means for controlling the communication of said head with the interior of said bellows, and for placing said vacuum head in communication with ambient air while maintaining a negative pressure within the interior of said bellows.

11. A device as claimed in claim 10 including manually operable means for operating said second valve means from a remote location.

12. A device as claimed in claim 10 including means for automatically actuating said second valve means on contact with the load.

13. A device as claimed in claim 10 including end plates closing the opposite ends of said bellows,

said means including articulated mechanism connecting said plates to one another.

14. A device as claimed in claim 10 wherein said vacnum head encompasses a greater cross-sectional area than that of said bellows so that the force holding said head against a load to be lifted slightly exceeds the force required to lift the load.

15. In a vacuum type load handling apparatus,

a bellows closed at its opposite ends,

a pair of spaced parallel plates for said bellows arranged generally at right angles to the longitudinal axis of said bellows,

said mechanism including a plurality of upper and lower links connected to said plates and to each other by universal connecting means,

said universal connecting means connecting the upper and lower links to each other being mounted on a third plate parallel to said pair of plates,

the universal connecting means on a plate being equally spaced from each other,

1 1 said pair of plates being rigidly connected, one to one end of said bellows and'the other to the other end of said bellows. 16. In a vacuum type load handling apparatus, a bellows closed at its opposite ends,v a pair of spaced parallel plates for said bellows arranged generally at right angles to the longitudinal axis of said bellows, means for maintaining said plates in alignment despite laterally directed forces being imposed against one while the other is restrained against bodily movement, said means including articulated mechanism connecting said plates to one another, said articulated mechanism including a first set of links connected to said plates by universal connecting means, the universal connecting means on each said plate being equally spaced from each other, one of said plates being rigidly connected to one end of said bellows, the other of said plates including a second articulated mechanism having a second set of links connected to said other plate and to a third plate parallel to said pair of plates by universal connecting means, said third plate being rigidly secured to the other end of said bellows, said second set of links being disposed so that any turning movement imparted by such links to said other plate is not cumulative but is subtractive. 17. In a vacuum type load handling apparatus, a bellows closed at least at one end by an end plate, the opposite end of said bellows having a sealing means providing a vacuum head for engaging a load, stabilizing means for maintaining the opposite ends of said bellows in alignment despite laterally directed forces being imposed against one 'end while the opposite end is restrained against bodily movement, said means including articulated mechanism within said bellows connecting said plate to the opposite end of said bellows, said articulated mechanism including at least three link means, each including upper and lower links connected to each other and to said plate and the opposite end of said bellows by universal connections, the distance between the opposite ends of said bellows being less than the length of a link means, passage means providing communication between the interior of said bellows and said vacuum head, and valve means for controlling communication of the interior of said bellows with the ambient air. 18. In a suction-type load pickup apparatus,

a bellows including means closing said bellows at its opposite ends,

means supporting said bellows with its longitudinal axis vertical,

a vacuum head at the lower end of said bellows for engaging a load,

a source of vacuum,

passage means connecting the interior of said bellows and said vacuum head with said source of vacuum,

control means having a valve means which in a first position is operable to place the interior of said bellows and said vacuum head in communication with ambient air, while at the same time also placing the said vacuum head in communication with said source of vacuum,

said valve means in a second position being operable to place said vacuum head in communication withambient air while cutting off the source of vacuum to the head and preventing communication of the interior of said bellows with ambient air so as to maintain a negative pressure in said bellows to thereby maintain said bellows in its position at that time while said head releases a load, said valve means in its first position also being operable to maintain at least a suflicient negative pressure in said vacuum head to permit said bellows to expand before said head releases said load. 19. An apparatus according to claim 18 wherein said control means includes means for preventing retraction of said bellows before said vacuum head engages said load when said vacuum head and said bellows are both placed in communication with said source of vacuum.

References Cited by the Examiner UNITED STATES PATENTS 1,222,535

GERALD M. FORLENZA, Primary Examiners R. B. JOHNSON, Assistant Examiner.

Claims

10. IN A SUCTION TYPE LOAD PICK-UP APPARATUS. A BELLOWS CLOSED AT ITS OPPOSITE ENDS, MEANS SUPPORTING SAID BELLOWS WITH ITS LONGITUDINAL AXIS VERTICAL, A VACUUM HEAD AT THE LOWER END OF SAID BELLOWS FOR ENGAGING A LOAD, A SOURCE OF VACUUM COMMUNICATING WITH THE INTERIOR OF SAID BELLOWS, FIRST VALVE MEANS FOR PLACING THE INTERIOR OF SAID BELLOWS IN COMMUNICATION WITH THE AMBIENT AIR, AND SECOND VALVE MEANS FOR CONTROLLING THE COMMUNICATION OF SAID HEAD WITH THE INTERIOR OF SAID BELLOWS, AND FOR PLACING SAID VACUUM HEAD IN COMMUNICATION WITH AMBIENT AIR WHILE MAINTAINING A NEGATIVE PRESSURE WITHIN THE INTERIOR OF SAID BELLOWS.