US3647183A

US3647183A - Vehicle jack

Info

Publication number: US3647183A
Application number: US68809A
Authority: US
Inventors: Sigurd A Rishovd
Original assignee: ROYAL IND
Current assignee: BRANICK INDUSTRIES Inc 2600 - 3RD AVE NO FARGO ND A CORP OF ND; Royal Industries Inc; ROYAL IND
Priority date: 1970-09-02
Filing date: 1970-09-02
Publication date: 1972-03-07
Anticipated expiration: 1989-03-07

Abstract

A fluid operated lift jack for vehicles or the like having a first stop means for limiting downward movement of the jack cylinder and a second stop means for limiting upward movement of the cylinder, said stop means yieldably retained in operative position, a single control for selectively admitting or withdrawing fluid from the jack to raise or lower the cylinder, and said control having connection with said stop means to make the second stop means inoperative during raising and the first stop means inoperative during lowering of the cylinder.

Description

Rishovd Mar. 7, R972 [54] VEHICLE JACK Primary Examiner-Othell M. Simpson [72] Inventor. Sigurd A. Rlshovd, Minneapolis, Mmn. Auomey caflsen Came & sum" [73] Assignee: Royal industries, lnc., Osseo, Minn. 22 Filed: Sept. 2, 1970 [571 [21 Appl No: 68,809 A fluid operated lift jack for vehicles or the like having a first stop means for limiting downward movement of the jack cylinder and a second stop means for limiting upward move- [52] U.S.Cl. ..254/2 B, 254/93 H "mm f the cylinder, said stop means yieldably retained in [5 1] int. Cl ..B60p 1/00 operative position, a single comm for selectively admitting or [58] new 0! Search "254/2 2 2 93; 91/41 withdrawing fluid from the jack to raise or lower the cylinder,

91/45 and said control having connection with said stop means to make the second stop means inoperative during raising and [56] Rate Cited the first stop means inoperative during lowering of the UNITED STATES PATENTS cylinder- 2,805,839 9/1957 Branick ..2S4/93 R 5 Cl 6 Drawing Figures i l K i in H PATENTEDHAR 11912 SHEET 1 [IF 2 8/61/20 19. zP/swarp ,"H Illh W W \mm VEHICLE JACK BACKGROUND OF THE INVENTION This invention relates generally to fluid operated jacks for lifting vehicles, trailers, boats or the like and more particularly concerns stop mechanism in such jacks for locking the jack against accidental and rapid expansion or contraction.

Some vehicle jacks which are operated by hydraulic or pneumatic pressures are provided with a mechanical stop means such as a tooth and ratchet to prohibit the jack from collapsing in the event of fluid leakage. Such a stop means is preferably operative during lifting movement or extension of the jack.

However, it is also desirable to provide stop means to restrict upward or explosive movement of the jack. This may occur when weight or pressure is suddenly removed from the jack such as when a vehicle slips off of it and the internal fluid pressure in the jack cylinder tends to cause it to extend.

For sake and convenience and clarity of understanding the stop means prohibiting contraction or lowering of the jack will be referred to as the down stop means while the stop means prohibiting extension or raising will be referred to as the up stop means.

In an ideal structure both stop means are operative when the jack is in neutral position, being neither extending or contracting, while only the down stop means is operative as the jack is being extended and only the up stop means is effective as the jack is being contracted.

The invention is an improvement over US Pat. Nos. 2,805,839 and No. 2,838,027 to Branick which are generally directed toward the same objectives The primary object of the present invention is to provide a fluid operated jack for vehicles or the like with mechanical stop means operated by the fluid control means for limiting extension or retraction of the jack where leakages occur or where great pressures are suddenly applied to or removed from the jack.

Another object of the invention is to provide two independent stop means in a jack for restricting expansion and contraction movement wherein both stop means are normally spring held in locking engagement but which may be independently removed from locking engagement to permit extension or retraction of the jack by fluid transfer.

Still another and more specific object of the invention is to provide a fluid operated extensible and contractable jack with stop means for limiting movement in either direction and wherein a single control operates the fluid means and the stop means whereby one stop means is operative when the jack is extended and the other stop means is operative when the jack is contracted.

With these and other objects in view the invention broadly comprises an upright fluid extensible jack carrying a lifting device for engagement under a vehicle frame, a valve device for selectively admitting or draining fluid under pressure from the jack, a fixed support base for the jack having an upright post with a series of oppositely directed rachet teeth at either side thereof, a pair of selectively operable latch members respectively engageable with said ratchet teeth, and a single manual control for simultaneously operating the valve device and latch members.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a side elevation of the jack taken on line l-l of FIG. 2 showing the jack in lowered or contracted condition with the upper portion thereof partially broken away to enable better understanding of the construction.

FIG. 2 is a front elevation of the jack in the same condition as shown in FIG. 1 with the lift arms broken away to conserve space.

FIG. 3 is an enlarged fragmentary vertical section through the central portion of the jack taken on line 3--3 of FIG. 1 and DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now more particularly to the drawings, reference numerals will be used to denote like parts or structural features in the different views. The jack is denoted generally by the number 10 and includes a base platform 11 supported on front and rear wheels denoted respectively at 12 and 14. An elongated tube 15 which is square in cross section is mounted on the base platform in fixed upright position.

The sidewalls of tube 15, referred to as left and right sidewalls when viewed in FIGS. 3 to 6, are respectively designated by

numerals

16 and 17. The left sidewall 16 has a row of tabs 18 punched inwardly therefrom to project at an upwardly extending angle within the tube as shown in FIG. 3. These tabs have their curved upper edges punched out with each leaving an arched downwardly facing stop edge 19 in wall 16. The right sidewall 17 has a row of tabs 20 punched inwardly therefrom to project at a downwardly extending angle within the tube. These tabs project in just the reverse direction from tabs 18 with the lower edges thereof punched from wall 17 each leaving an arched upwardly facing stop edge 21.

At its upper end the tube 15 is capped by a bearing member 24 having a sealing ring 25 mounted peripherally thereon and a piston cup 26 mounted on the top thereof. The structure hereinabove described constitutes the base or fixed portion of the jack.

The extensible portion of jack 10 is designated generally by the numeral 30. This includes a cylinder member 31, closed at its upper end by plate 32 and slidably encircling the bearing and

piston members

24 and 26 and tube 15 to form an extensible jack assembly therewith. A U-shaped bracket 34 of channel material has its legs 35 welded to the sides of the cylinder 31 and extends downwardly therefrom on either side of the post 15. The cross portion 36 of bracket 34 has an opening (not shown) through which post 15 extends.

A pair of plates 38 rigidly secured one to each bracket leg 35 extend rearwardly from the bracket in slightly diverging relation over base platform 11. Near their extended ends these plates jointly support an upwardly opening cross channel 39 within which aligned lift arms 40 have their inner ends pivoted on bolts 41 for movement between an extended operating position as in FIG. 2 and an upwardly folded nonoperating position. Saddle members 42 for engaging under an automobile frame or bumper bracket in lifting relation thereto, shown partially in FIG. 2, are mounted on each of the lift arms 40.

A valve 44 mounted on cylinder 31 is adapted for connection with a standard compressed airhose. Valve 44 connects the hose with a line 45 which has an open connection with chamber 46 at the upper end of cylinder 31 through coupling 47. A valve actuator 48 is pivoted at 49 on the valve. When the actuator is in neutral position as shown in FIG. 2, the valve 44 is closed so that air can neither enter or leave the chamber 46. When the right side of the actuator 48 is tilted upwardly, as viewed in FIG. 2, air will be admitted into chamber 46 to raise cylinder 31 and extend the jack. Conversely, when the left side of the actuator is tilted upwardly, air is allowed to drain from chamber 46 through the valve to atmosphere, thus lowering cylinder 31 and contracting the jack.

Tilting of actuator 48 to operate valve 44 is accomplished by a control rod 50. This rod is journaled for oscillating movement in vertically spaced bearings 51 mounted on the cylinder 31 and has its upper end bent outwardly to form an upper handle 52. The lower portion of the rod 50 is offset inwardly as at 54 and then bent outwardly to form a bottom handle 55.

The stop mechanism is designated generally by the numeral 57 and is mounted on the bracket 34. A pair of

latch members

58 and 59 are mounted one in each of the bracket legs 35 in transversely opposing relation for sliding movement toward and away from each other on a common axis. Each latch member may have its inner end portion supported by the adjacent plate 38 through which it extends.

Each latch member carries a cross pin 61 and a spiral spring 62 encircling the member and held under compression between the pin. A leg 35 urges the latch member inwardly against the tube 15. Latch member 58 has its inner end beveled as at 64 on its underside with the end positioned to latch under the edges 19. Latch member 59 has its inner end beveled as at 65 on its upper side with the end positioned for latching engagement over the edges 21.

A latch release strap 70 having a generally U-shape is mounted on the bracket 34 at the level of the latches. The strap has a pair of slots 71 (FIG. 2) each of which receives a bolt 72 allowing the strap lateral sliding movement. The end portions of the strap extend rearwardly along the sides of bracket 34 and are slotted as at 74 (FIG. 1) to receive the outer ends of the latches S8 and 59. Cross pins 75 are provided in the latches outside of the strap. A bearing ring 76 is mounted medially on the strap and the offset portion 54 of rod 50 extends therethrough.

In operation the jack or lift is wheeled into the proper lifting position relative to the front or rear end of a vehicle by means of handles 78 mounted near the top of the cylinder. The jack is positioned so that the saddle members 42 will engage under transversely spaced portions of the vehicle frame when the jack is extended.

An air pressure hose is then attached to valve 44. Handle 52 (or handle 55) is then turned to the right as viewed in FIG. 2 tilting the right side of actuator 48 upwardly and causing valve 44 to admit air through line 45 to chamber 46. This causes the entire extensible portion 30 of the jack to raise including the plates 38 and lift arms 40 raising the vehicle to the desired position.

As the handle 52 is turned to the right rod 50 will turn in bearings 51 causing the rearwardly offset portion 54 of the rod to shift to the left moving strap 70 therewith to the position shown in FIG. 5. Accordingly, latch member 58 is removed from engagement with post 15. As the jack extends the bracket 34 carries latch member 59 upwardly along the wall 17 with the beveled surface 65 thereof sliding along the tabs 20. In the event that any leakage should occur in the air pressure system, latch 59 will provide a stop against the adjacent stop edge 2 ll preventing collapsing of the jack.

When the jack has been extended to the desired position handle 52 is returned to its centered position moving the stop mechanism to its neutral position shown in FIG. 4 bringing latch 58 again into engagement with the stop edges 19 on wall 16 and the extensible portion 30 of the jack is locked against movement in either direction.

To contract the jack the handle 52 is again turned to the right so as to extend the jack slightly so that both latches 58 and 59 are disengaged from

edges

19 and 21. The handle is then turned to the left as viewed in FIG. 2 tilting the left side of actuator 48 upwardly. This adjusts valve 44 to open chamber 46 to atmosphere through line 45. With this movement of rod 50 the stop mechanism 57 is shifted to the position shown in FIG. 6 withdrawing latch 59 from engagement with the wall 17 but leaving latch 58 in ratcheting engagement with tabs 18 in wall 16. Accordingly, if weight is suddenly removed from lifting arms 40, the latch 58 will engage against the stop edge 19 immediately thereabove preventing rapid exploding or extension of the jack.

The invention thus provides a construction wherein a single control operates the jack and the stop mechanism 57 so that positive safety locking action is automatically provided during either extension or contraction.

Having now therefore fully illustrated and described my invention, what I claim to be new and desire to protect by United States Letters Patentjs:

1 In a vehicle ack having a base, a fluid actuated lift member mounted on the base for raising and lowering movement, a fluid cylinder associated with the lift member, valve means for admitting fluid to and discharging it from the cylinder, an upright member on the base having one row of upwardly directed stop teeth and a second row of downwardly directed stop teeth, first and second latch members mounted on the lift member and in yieldable engagement respectively with said first and second rows of teeth to lock the member against raising and lowering movement, a single control means movable to one position for simultaneously admitting fluid to the cylinder to raise the lift member and to make said second latch member inoperative and to a second position for simultaneously discharging fluid from the cylinder to lower the lift member and to make said first latch member inoperative.

2. The subject matter of claim 1 wherein said latch members are disposed in opposing horizontal alignment on the lift member, said valve means being mounted on the lift member in spaced relation above the latch members, and said control means comprising an elongated rod joumaled in vertical position on the lift member for oscillating movement with the upper portion of the rod having operative connection with the valve means and the lower portion of the rod having operative connection with the latch members.

3. The subject matter of claim 2 wherein said rod has radially extending handles for oscillating the rod at both its upper and its lower ends.

4. In a fluid operated lift jack for vehicles or the like,

a. a support base,

b. an elongated tube mounted integrally in upright position on the base and having a piston head on its upper end,

c. a lift cylinder having a closed upper end mounted on the piston for vertical sliding movement axially of the tube and having a vehicle lifting bracket thereon,

d. means for admitting air under pressure to and discharging it from the lift cylinder above the piston for selectively raising or lowering the cylinder,

e. means forming rows of ratchet teeth on opposing sides of the tube,

. a pair of opposing latch members supported by the cylinder in position to be engageable one with each row of ratchet teeth,

g. a single control for the air means and the latch members adapted to move one latch member to a nonoperative position when air is admitted to the cylinder and to move the other latch member to a nonoperative position when air is discharged from the cylinder.

5. The subject matter of claim 4 wherein h. each of said latch members is provided with a spring means urging it inwardly into engagement with the ratchet teeth,

i. a bracket member mounted on the cylinder for lateral shifting movement and having connection with each of said latch members,

j. and said control comprising an upright rod journaled on the lift cylinder and connected to the bracket member at a point offset from its turning axis whereby as the rod is rotated in one direction it will shift the bracket in one direction to move one latch member outwardly against its spring means and when rotated in the opposite direction will move the other latch member outwardly against its spring means.

Claims

1. In a vehicle jack having a base, a fluid actuated lift member mounted on the base for raising and lowering movement, a fluid cylinder associated with the lift member, valve means for admitting fluid to and discharging it from the cylinder, an upright member on the base having one row of upwardly directed stop teeth and a second row of downwardly directed stop teeth, first and second latch members mounted on the lift member and in yieldable engagement respectively with said first and second rows of teeth to lock the member against raising and lowering movement, a single control means movable to one position for simultaneously admitting fluid to the cylinder to raise the lift member and to make said second latch member inoperative and to a second position for simultaneously discharging fluid from the cylinder to lower the lift member and to make said first latch member inoperative.

2. The subject matter of claim 1 wherein said latch members are disposed in opposing horizontal alignment on the lift member, said valve means being mounted on the lift member in spaced relation above the latch members, and said control means comprising an elongated rod journaled in vertical position on the lift member for oscillating movement with the upper portion of the rod having operative connection with the valve means and the lower portion of the rod having operative connection with the latch members.

4. In a fluid operated lift jack for vehicles or the like, a. a support base, b. an elongated tube mounted integrally in upright position on the base and having a piston head on its upper end, c. a lift cylinder having a closed upper end mounted on the piston for vertical sliding movement axially of the tube and having a vehicle lifting bracket thereon, d. means for admitting air under pressure to and discharging it from the lift cylinder above the piston for selectively raising or lowering the cylinder, e. means forming rows of ratchet teeth on opposing sides of the tube, f. a pair of opposing latch members supported by the cylinder in position to be engageable one with each row of ratchet teeth, g. a single control for the air means and the latch members adapted to move one latch member to a nonoperative position when air is admitted to the cylinder and to move the other latch member to a nonoperative position when air is discharged from the cylinder.

5. The subject matter of claim 4 wherein h. each of said latch members is provided with a spring means urging it inwardly into engagement with the ratchet teeth, i. a bracket member mounted on the cylinder for lateral shifting movement and having connection with each of said latch members, j. and said control comprising an upright rod journaled on the lift cylinder and connecTed to the bracket member at a point offset from its turning axis whereby as the rod is rotated in one direction it will shift the bracket in one direction to move one latch member outwardly against its spring means and when rotated in the opposite direction will move the other latch member outwardly against its spring means.