US2972394A - Portable elevator - Google Patents

Description

Feb. 21, 1961 P. D. GRANT 2 972,394

PORTABLE ELEVATOR Filed March 28, 1958 2 Sheets-Sheet 1 Gertrude 8. Grant, E xecutrix of the Estate of Paul 0. Grant, Deceased.

1 N VEN TOR.

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Feb. 21, 1961 P. D. GRANT PORTABLE ELEVATOR 2 Sheets-Sheet 2 Fig. 4

Filed March 2a, 1958 I2 Fig-3 4 2 M I! O r m m C4!) 0 w B0 r 4 4M6. 8 m0 5 rl 8m 6w 5 0 M U m a d GE IN VIiNIOR.

Amway:

United States Pate t PORTABLE ELEVATOR Paul D. Grant, deceased, late of Bakersfield, Calif. by

Gertrude B. Grant, executrix, 3013 Haley St., Bakersfield, Calif.

Filed Mar. 28, 1958, Ser'. No. 724,536

2 Claims. (Cl. 187-11) This invention relates to a portable elevator and more particularly to an elevator which is adapted to lift small heavy objects so that they can be more easily applied on shelves in warehouses, book stores and in a variety of other places.

An object of the present invention is to provide a portable elevator which has a novel supporting structure within which a platform is vertically movable. The platform is driven by an electric motor and a series of cables and pulleys that attach to a transmission that is actuated by the motor. It is preferred that the motor have a built in brake so that as soon as the power is turned off, as by actuating a switch, the brake automatically is applied so and provide long, satisfactory service. This is accomplished by the particular supporting structure which may be either a closed panel or an open web or a combination of both, in addition to the unique elevating'mechanism including the configuration of the platform, which is supported by the structure.

A further object of the present invention is to provide an elevator capable of being raised and lowered, wherein there are upper and lower limit switches to stop the motion of the elevator platform when the extreme positions are reached.

Other objects and features of importance will become apparent in following the description of the illustrated form of the invention. r

In the drawings:

Figure 1 is a perspective view of an elevator constructed in accordance with the invention.

Figure 2 is a top view of the elevator in Figure 1.

Figure 3 is a vertical sectional view of the elevator.

Figure 4 is a'sectional view taken on the line 4-4 of Figure 3. 1

Figure 5 is a transverse sectional view taken on the line 5--5 of Figure 4.

Figure 6 is a wiring diagram showing one suggested manner of wiring the elevator. 1.

In the accompanying drawings there is an elevator 10 which is constructed in such a manner as to demonstrate 7 2,972,394 Patented Feb. 21 1961.

support structure and has the lower .ends of a pair of L- shaped guard rails 42 and 44 secured. thereto. The upper parts of the guard rails have extremities which are attached to the riser 34, as by being welded or otherwise fastened. A chain extends across the guard rails and has a catch 52 at one end to attach to one of the guard rails. and/or personnel who may use the elevator.

In order to power the elevator, that is to raise the platform 26, there is an electric reversible motor which is bolted or otherwise fastened to the bottom wall 20 by the motor mounting flanges 62 and bolts. The electric cord for motor 60 preferably operatively connects with an automatic rewind device 63. An electromagnetic or other type of clutch 64 is built in with a motor and operates automatically in response to deenergization of the motor 60. Hence, as soon as the electric power is removed from motor 60, the brake automatically applies with ample force to stop rotation of the armature shaft of the motor practically instantaneously. The armature shaft is attached to a shaft of transmission 66 that is provided with a power output shaft 68 on which multiple pulleys 70 are secured. There are four such pulleys and four cables in pairs 72, 73 and 74, 75 which are attached to the multiple pulleys. Cables 72 and 73 are guided by lower pulleys 76 and 78 (Figure 4) attached to the side wall 16 of the support structure 12. They are entrained over the upper pulleys 78 and 80 attached to the same side wall 16 and extending downwardly for attachment to the side 40 of the platform. Cables 74 and 75 are entrained'over lower pulleys 84 and 85 andupper pulleys 86'and 87 at the lower and upper ends of wall 14 of supporting structure 12. 'These cables 74 and 75 are attached by brackets 88 and 89 (Figure 4) to the side 38 of the elevator platform 26. Flexible curtains covering the cables and. pulleys can be disposed between the guard rails 42 and 44 as a protective measure. I

Automatically closed limit switch 90 and 91 are attached to side 38 of the platform 26 and they strike lower and upper abutments 92 and 93 attached to the inner surface of, supporting structure side 14. Switches 91 and 90 have switch arms on which there are rollers which make actual contact with the inwardly protruding abutments.

In operation, a manual switch 96 having up and down buttons will be used." It is preferred that this switch be attached to the platform so that it can move upand down with it. The switch 96 is schematically shown in Figure 6, as is one suggested wiring for the elevator. This schematic representation shows a thermal overload circuit breaker 97 in one side of the line 98, this same side having the parallel connected up and down switch sections of switch 96' arranged in parallel. They are re- 7 spectively connected in series with theupper limit switch the principles of the invention. The elevatorincludes a 1 supporting structure 12 that has sides or side walls 14 and 16 together with a back wall 18 and a bottom or bottom wall 20. The top and front 22 of the support structure 12 is open. Wheels 24 which may be of the caster or fixed spindle type, are attached to the bottom 91 and the lower limit switch '90 so that a parallel path is establishedfor the up and down movement of the reversible motor 60, and each path has its energization' button plus a limitiswitch serially connected with it.

Although the'jelevator platform isactually driven in a down direction by the reversal of motor 60, the invention could well be practiced by having the elevator wholly or entirely gravity lowered rather than partially gravity lowered or at least aided in the downward movement by .the' pull of gravity. Other switch arrangements could be adopted as well-as various other modifications made without departing from. the claimed invention.

What is claimed as new is as followsi 1. An elevator comprising a supporting structure which has a bottom, sides, and means attached to said sides holding said sides spaced from each other, said structure having an open top and an open front and constituting a guideway, a platform vertically movably, disposed in said guideway between said sides, said platform having a part The chain functions asa safety device for articles I which is accessible through the open front of said structure, an electric motor, drums connected to said electric motor and located at opposite sides of said motor, cables oppositely wound on said drums and operatively connected with said platform to elevate said platform in response to actuation of said motor, guides atthe upper and lower parts of said supporting structure over which said cables are entrained, means responsive to the movement of said platform to a particular height for de-energizing said motor, and an automatic brake operatively connected with said motor and which becomes engaged to mechanically stop the motor from turning in response to de-energization of said motor.

2. The elevator of claim 1 wherein said platform has at least one step, and a guard rail connected to said step 15 and having a portion which protrudes inwardly between said sides of said supporting structure.

References Cited in the file of this patent UNITED STATES PATENTS 1,051,247 McLendon I an. 21, 1913 1,093,929 Hankey Apr. 21, 1914 1,283,498 Goad Nov. 5, 1918 1,924,751 Porter Aug. 29, 1933 2,516,726 Sexton July 25, 1950 2,581,887 Saxton Jan. 8, 1952 2,599,052 Forman June 3, 1952 2,762,659 Harlan Sept. 11, 1956 2,824,623 Nord Feb. 25, 1958

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