US3764106A

US3764106A - Pressure operated lift

Info

Publication number: US3764106A
Application number: US00205653A
Authority: US
Inventors: L Klassen; D Frost
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-12-07
Filing date: 1971-12-07
Publication date: 1973-10-09
Anticipated expiration: 1990-10-09

Abstract

A vertically adjustable power lift incorporating a wheel mounted U-shaped base frame and a similarly configured load-supporting top frame mounted thereover for vertical adjustment by means of an articulate cross link unit. Pulley guided cables extend from the articulate unit to a controlled power unit for a control of the raising and lowering of the top frame and load.

Description

United States Patent [191 Klassen et al.

[ Oct. 9, 1973 PRESSURE OPERATED LIFT [76] Inventors: Laverne M. Klassen; Doris V. Frost,

both of 114 W. Main, Turlock, Calif. 95380 22 Filed: Dec. 7,1971

21 Appl. No.: 205,653

[52] US. Cl 254/8 R [51] Int. Cl. B60p 1/48 [58] Field of Search 254/4 R, 4 BC, 8,

254/9, 10 R, 10 13,10 C, 2 R, 2 B, 2 C, 93 R, 122, 124, 126, 127; 214/390; 187/18 [56] References Cited 7 UNITED STATES PATENTS 2,487,508 11/1949 Anderson 214/390 1 2,937,003 5/1960 Croll 254/93 R 2,830,854 4/1958 Cottar 254/9 C FOREIGN PATENTS OR APPLICATIONS 138,168 2/1949 Australia 254/4 R 831,541 3/1960 Great Britain 254/10 C Primary Examiner-Othell M. Simpson Assistant Examiner-Robert C. Watson Attorney-Harvey B. Jacobson et al.

[57] ABSTRACT I A vertically adjustable power lift incorporating a wheel mounted U-shaped base frame and a similarly configured load-supporting top frame mounted thereover for vertical adjustment by meansof an articulate cross link unit. Pulley guided cables extend from the articulate unit to a controlled power unit for a control of the raising and lowering of the top frame and load.

8 Claims, 4 Drawing Figures Patented Oct. 9, 1973 2 Sheets-Sheet 1 2 Sheets-Sheet 2 PRESSURE OPERATED LIFT The present invention is generally concerned with a power operated lift utilizing a controlled hydraulic system. More particularly, the invention is directed to a lift uniquely adapted for use in bakeries, schools, hospitals, and the like for the handling of large mixer bowls, sacks of flour, and similar heavy loads.

[t is a primary object of the invention to provide a lift which is specifically adapted for the handling of large kitchen or bakery equipment and supplies for a movement thereof as required including the positioning of mixer bowls on dollies and scales and the removal of the mixer bowls therefrom, the lift also enabling a raising of the mixer bowls to any convenient working height.

In conjunction with the above object, it is a significant object of the invention to provide a lift uniquely adapted, through an open ended configuration, to straddle mixer bowls or the like for an engagement with the sides thereof in a manner which leaves the bottom of the mixer bowl free for depositing on dollies, scales, and the like, as well as a simiplified removal therefrom.

Further objects of the invention include the provision of a lift which is compact, highly mobile and easily operated.

Basically, the lift includes a wheel supported base frame mounting a top frame thereover through selectively extensible and collapsible scissors-type linkages.

The linkages are controlled through pulley guided cables operatively connected to a pressure actuated piston rod.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout and in which:

FIG. 1 is a top plan view of the lift comprising the instant invention;

FIG. 2 is a side elevational view of the lift in its collapsed position;

FIG. 3is a side elevational view of the lift in its extended position; and

FIG. 4 is a rear elevational view of the lift.

Referring now more specifically to the drawings, reference numeral is used to generally designate the lift comprising the invention. The lift 10 includes a base frame 12 of a generally U-shaped configuration, incorporating a pair of laterally spaced side rails 14 rigidly interconnected by a transversely extending back rail 16, defining an open forward end which allows for a straddling of -a mixer 18 or the like.

The base frame 12 mounts on four swivel rollers 20 secured to and depending from the opposed ends of the two side rails 14.

A top frame 22, of the same general configuration as the base frame 12, isprovided in parallel overlying relation to the base frame 12. This top frame, including laterally spaced side rails 24 and a transverselyextending rear rail 26 likewise defines an open forward end for a straddling of the load.

The load is to be directly supported on the top frame 22 with this frame 22 being vertically adjustable relative to the base frame 12 for a selective raising or lowering of a load. The top frame 22 and base frame 12 are and 12. The upper and lower forward link ends are respectively received between frame rail mounted tracks 32 for a sliding retention of link and mounted cross pins 34. Each of these pins 34 can, if so desired, have appropriate slides or rollers mounted on the track confined outer extremities thereof. This sliding movement of the forward ends of the upper and lower links 28 allows for the free expansion and collapsing of the scissor frames 26 and a corresponding vertical adjustment of the upper frame 22.

The power controls for the lift 10 are mounted primarily on the rear rail 16 of the base frame 12 and include a fluid reservoir 36, a pump 38 and a hydraulic cylinder 40 having an outwardly directed piston rod 42 through the pump lever 46 and pressure release 48 is in itself conventional. Of particular interest with regard to the fluid reservoir 36, pump 38 and ram unit 40 and 42 j is the compact longitudinal orientation thereof along the rear rail 16, maintaining the interior of the lift free of interfering projections or the like, while at the same time providing only minimal rail projection, such rail projection infact being no greater than that of the vertical lift manipulating handle 50. The handle 50, as

. will be noted from the drawings, consists of an elevated cross bar integrally formed with apair of depending side posts, the lower ends of which are rigidly affixed to the opposed end portions of the rear base frame rail 16.;

In order to transmit the movement of the piston rod 42 to a corresponding movement of the scissor frames 26, a pair of

elongated control cables

52 and 54 are provided. The

cables

52 and 54 are affixed to the opposed ends of the rod crosshead 44 and extend toward a first end of the rear rail 16 and about a pair of bracket mounted

pulleys

56 and 58.'The cable 52 extends from the pulley 56 forwardly and upwardly along the adjacent side rail 14 for engagement over an elevated vertically orientated post mounted pulley 60. generally aligned with and slightly outward of the central portion of the adjacent scissors frame'26. The cable 52 extends downwardly beyond the pulley 60 and is pivotally affixed to a bracket 62 mounted on one of 'the links 28 in a manner whereby'a tensioning of the cable 52, I

through an extension of the rod 42' will effect an up ward drawing of the link mounted bracket 62 and a corresponding upward swinging of the pivotally interconnected remaining links. As indicated, the positioning of the pulley 60 is effected through a vertically elongated post 64 afiixed to the outer face of the corresponding side rail '14.

The second cable 54, after passing about the first end mounted pulley 58, extends generally parallel along the rear rail 16 and about a second bracket mounted pulley 66 positioned at the second end of the rear rail 16. The cable 54 then extends forwardly and upwardly along the second side of the base frame 12 for engagement over an elevated post mounted pulley 68 similar to and opposed from the pulley 60. The cable 54 then extends downwardly for pivotal engagement with a. link mounted bracket on the second scissors frame 26 for an operation thereof in the manner previously described in conjunction with the cable 52.

The control system, constructed as above, provides an equal lifting load on the two opposed scissors frames to insure a level operation of the lift with the lifting force being applied along the opposed load receiving side rails 24 of the top frame 22. If so desired, appropriate cable length adjusting means can be utilized, note for example turnbuckle 70.

With reference to FIG. 1 in particular, in order to adapt the top frame 22 to various size mixers and the like, a pair of opposed hinge mounted plates 72 are mounted on the two top frame side rails 24 for engagement beneath pot or mixer flanges, lifting lugs or han dles. Each of the plates 72 includes an upwardly projecting stabilizing or positioning lug 74. Further, in order to lock the received mixer, pot or the like on the top frame, a pivotally mounted holding arm 76 is mounted centrally on the top frame cross rail 26 for selective orientation into a retaining position.

From the foregoing, it will be appreciated that a compact highly versatile power lift has been devised. The lift, through the dual scissor frames, eachindividually cable controlled, provides a positive balanced lift action. In addition, the open front of the lift particularly adapts it for stradling large mixers, pots, kettles and the like for a raising, carrying and lowering thereof without necessitating any manual manipulation of the'mixer in either the loading or unloading thereof onto the lift or from the'lift. Incidentally, while the lift is particularly adapted for straddling and liftingg mixers and the like, it can also be easily adapted'for the accommodation of bulk loads such as sacks of flour or the like. All that is required is the positioning of an inverted baking pan onthe top frame, a locking of the pan by the holding arm 76 and a vertical adjustment of the lift to bring the frame supported pan to the level of the sack or the like. The sack is then easily horizontally shifted onto the pan and from that point on power controlled by the lift mechanism.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications andtween the spaced side members, said extension frame comprising two sections, each section extending vertically between the corresponding side members of the base frame and the top frame and defining an open article receiving area between the side members, a power unit mounted between the side members of the base frame opposed from the side member defined open end, and force transmitting means engaged between the power unit and each extension frame section for effecting a powered control thereof, each extension frame section being of a scissor-type crossed link construction, said power unit including a selectively extensible and retractable hydraulically controlled piston rod, the force transmitting means comprising a pair of cables fixed to the piston rod, each cable extending from the rod to one extension frame section, and pulleys guiding each cable.

2. The lift of claim 1 wherein one pulley associated with each cable is mounted adjacent the corresponding extension frame section generally centrally thereof and at an elevated position relative to the base frame, the associated cable extending over this one pulley and downward into engagement with a link of the section located therebelow whereby a tensioning of the cable will effect a raising of the engaged link and a corresponding extension of the section and raising of the top frame. I

3. The lift of claim 2 including wheel means mounted on said base frame and depending therefrom for rolling engagement with the ground. 4

4. A power lift comprising a base frame and a top frame in overlying parallel relation to said base frame, an extension frame between said base frame and said top frame, said extension frame mounting said top frame for vertical adjustment relative to said base frame, said extension frame comprising a pair of laterally spaced vertically orientated scissor-type crossed link sections, a power unit mounted transversely across said base frame, said power unit including a selectively extensible and retractable hydraulically controlled piston rod, and a pair of cables fixed to said piston rod for control thereby, each cable extending from said rod to one of said extension frame sections, and pulleys guiding each cable between the piston rod and section, one

spaced side members defining an open end forthe reception of articles to be lifted therethrough and be- ,pulley associated with each cable being mounted adjacent the corresponding extension frame section gener ally centrally thereof and at an elevated position relativeto the base frame, the associated cable extending over this one pulley and downward into engagement with a link of the section located therebelow whereby a tensioning of the cable will effect at raising of the engaged link and a corresponding extension of the section and raising of the top frame.

5. A power lift comprising a base frame, a top frame in overlying parallel relation to said base frame, an extension frame between said base frame and said top frame and mounting said top frame for vertical adjustment relative to said base frame, said base frame and said top frame including, in each instance, laterally spacedside members defining an open end for the reception of articles to be lifted therethrough and between the spaced side members, said extension frame comprising two sections, each section extending vertically between the corresponding side members of the base frameand the top frame and defining an open article receiving area between the side members of a constant depth defined by the length of said side members,

a power unit mounted between the side members of the base frame opposed from the side member defined open end, said power unit being positioned transversely between the base frame side members and including a selectively transversely extensible and retractable hydraulically controlled piston rod, and force transmitting means engaged between the piston rod and each extension frame for effecting a powered control thereof and a selective raising and lowering of the top frame relative to the base frame, said raising and lowering being effected without varying the depth of the article receiving area between the side members.

6. The lift of claim 5 wherein the force transmitting means comprises a pair of cables fixed to the piston rod, each cable extending from the rod to one extension frame section, and pulleys guiding each cable.

7. A power lift comprising a base frame, atop frame in overlying parallel relation to said base frame, an extension frame between said base frame and said top frame and mounting said top frame for vertical adjustment relative to said base frame, said base frame and said top frame including, in each instance, laterally spaced side members defining an open end for the reception of articles to be lifted therethrough and between the spaced side members, said extension frame comprising two sections, each section extending vertically between the corresponding side members of the base frame and the top frame and defining an open article receiving area between the side members, a power unit mounted between the side members of the base frame opposed from the side member defined open end, and force transmitting means engaged between the power unit and each extension frame section for effecting a powered control thereof, said power unit including a selectively extensible and retractable hydraulically controlled piston rod, the force transmitting means comprising a pair of cables fixed to the piston rod, each cable extending from the rod to one extension frame section, and pulleys guiding each cable.

8. The lift of claim 7 wherein one pulley associated with each cable is mounted adjacent the corresponding extension frame section generally centrally thereof and at an elevated position relative to the base frame, the associated cable extending over this one pulley and downward into engagement with a portion of the section located therebelow'whereby a tensioning of the cable will effect a raising of the section and the top frame.

III t I t

Claims

1. A power lift comprising a base frame, a top frame in overlying parallel relation to said base frame, an extension frame between said base frame and said top frame and mounting said top frame for vertical adjustment relative to said base frame, said base frame and said top frame including, in each instance, laterally spaced side members defining an open end for the reception of articles to be lifted therethrough and between the spaced side members, said extension frame comprising two sections, each section extending vertically between the corresponding side members of the base frame and the top frame and defining an open article receiving area between the side members, a power unit mounted between the side members of the base frame opposed from the side member defined open end, and force transmitting means engaged between the power unit and each extension frame section for effecting a powered control thereof, each extension frame section being of a scissor-type crossed link construction, said power unit including a selectively extensible and retractable hydraulically controlled piston rod, the force transmitting means comprising a pair of cables fixed to the piston rod, each cable extending from the rod to one extension frame section, and pulleys guiding each cablE.

2. The lift of claim 1 wherein one pulley associated with each cable is mounted adjacent the corresponding extension frame section generally centrally thereof and at an elevated position relative to the base frame, the associated cable extending over this one pulley and downward into engagement with a link of the section located therebelow whereby a tensioning of the cable will effect a raising of the engaged link and a corresponding extension of the section and raising of the top frame.

3. The lift of claim 2 including wheel means mounted on said base frame and depending therefrom for rolling engagement with the ground.

4. A power lift comprising a base frame and a top frame in overlying parallel relation to said base frame, an extension frame between said base frame and said top frame, said extension frame mounting said top frame for vertical adjustment relative to said base frame, said extension frame comprising a pair of laterally spaced vertically orientated scissor-type crossed link sections, a power unit mounted transversely across said base frame, said power unit including a selectively extensible and retractable hydraulically controlled piston rod, and a pair of cables fixed to said piston rod for control thereby, each cable extending from said rod to one of said extension frame sections, and pulleys guiding each cable between the piston rod and section, one pulley associated with each cable being mounted adjacent the corresponding extension frame section generally centrally thereof and at an elevated position relative to the base frame, the associated cable extending over this one pulley and downward into engagement with a link of the section located therebelow whereby a tensioning of the cable will effect a raising of the engaged link and a corresponding extension of the section and raising of the top frame.

5. A power lift comprising a base frame, a top frame in overlying parallel relation to said base frame, an extension frame between said base frame and said top frame and mounting said top frame for vertical adjustment relative to said base frame, said base frame and said top frame including, in each instance, laterally spaced side members defining an open end for the reception of articles to be lifted therethrough and between the spaced side members, said extension frame comprising two sections, each section extending vertically between the corresponding side members of the base frame and the top frame and defining an open article receiving area between the side members of a constant depth defined by the length of said side members, a power unit mounted between the side members of the base frame opposed from the side member defined open end, said power unit being positioned transversely between the base frame side members and including a selectively transversely extensible and retractable hydraulically controlled piston rod, and force transmitting means engaged between the piston rod and each extension frame for effecting a powered control thereof and a selective raising and lowering of the top frame relative to the base frame, said raising and lowering being effected without varying the depth of the article receiving area between the side members.

7. A power lift comprising a base frame, a top frame in overlying parallel relation to said base frame, an extension frame between said base frame and said top frame and mounting said top frame for vertical adjustment relative to said base frame, said base frame and said top frame including, in each instance, laterally spaced side members defining an open end for the reception of articles to be lifted therethrough and between the spaced side members, said extension frame comprising two sections, each section extending vertically between the corresponding side members of the base frame and the top frame and defining an open article receiving area between the side members, a power unit mounted between the side members of the base frame opposed from the side member defined open end, and force transmitting means engaged between the power unit and each extension frame section for effecting a powered control thereof, said power unit including a selectively extensible and retractable hydraulically controlled piston rod, the force transmitting means comprising a pair of cables fixed to the piston rod, each cable extending from the rod to one extension frame section, and pulleys guiding each cable.

8. The lift of claim 7 wherein one pulley associated with each cable is mounted adjacent the corresponding extension frame section generally centrally thereof and at an elevated position relative to the base frame, the associated cable extending over this one pulley and downward into engagement with a portion of the section located therebelow whereby a tensioning of the cable will effect a raising of the section and the top frame.