US3759488A

US3759488A - Safety catch for hydraulic jacks for automobiles

Info

Publication number: US3759488A
Application number: US00208595A
Authority: US
Inventors: P Lukas
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-12-16
Filing date: 1971-12-16
Publication date: 1973-09-18
Anticipated expiration: 1990-09-18

Abstract

A rolling hydraulic auto jack has a shaft which telescopes to raise and lower an auto. The invention provides a metal channel or block which fits around the shaft to preclude a telescoping retraction thereof. This channel or block is a safety stop which keeps the jack from inadvertently lowering the auto, even if the hydraulic system fails.

Description

Waited States Patent 1191 Lukas 1 Sept. 18, 1973 [54] SAFETY CATCH FOR HYDRAULIC JACKS FOR AUTOMOBILES [76] Inventor: Paul Lukas, 3815 E. Layton Ave.,

' Cudahy, Wis. 53110 221 Filecl: Dec. 16, 1971 211 Appl. 110.; 208,595

[52] US. Cl. 254/8 R, 92/23 [5 1] Int. Cl 860p 1/48 [58] Flld of Search 254/8 R, 93 R; 92/15, 23, 30

[56] References Cited UNITED STATES PATENTS 3,135,555 6/l964 Caskey 92/23 2,998,224 8/196] Reisig 254/8R Primary Examiner-Othell M. Simpson Assistant Examiner-Robert G. Watson Attorney-lrwin C. Alter et al.

57 1 ABSTRACT A ,rolling'hydraulic auto jack has a shaft which telescopes to raise and lower an auto. The invention provides a metal channel or block which fits around the shaft to preclude a telescoping retraction thereof. This channel or block is a safety stop which keeps the jack from inadvertently lowering the auto, even if the hydraulic system fails.

'5 Claims, 5 Drawing Figures PATENTED l 3|975 FIG. 2

INVENTOR AUL LUKAS M CUW ATTORNEYS 1 SAFETY (IATCH FOR HYDRAULIC JACKS FOR AUTOMOBILES The invention relates to safety catches for rolling hydraulic floor jacks, for automobiles.

Hydraulic jacks are often built on rollers so that they may be pushed under an auto and then operated to raise it. Thereafter, it is necessary to perform some act to insure against an inadvertent lowering of the jack if the hydraulic system fails. Often, this act is a placing of an object, such as a cinder block, under an axle of the raised auto. That, or a similar act, insures the safety of a person crawling under the auto. However, it also takes time, and therefore is costly and wasteful.

Accordingly, an object of my invention, is to provide a device that may be applied to a conventional hydraulic jack, to insure against a release of it with safety.

Another object of my invention is to provide a device of the character described, that may be easily applied to the conventional rolling hydraulic jack.

Still another object is to provide a device of the described type which releases the hydraulic jack, without requiring any additional mechanical equipment or further modification of the jack.

Other and further objects of the invention will become more apparent as the description proceeds, when taken in conjunction with the drawings, in which:

FIG. 1 is a perspective view of the assembled safety catch device,

FIG. 2 is a top or plan view of the assembled device of FIG. 1;

FIG. 3 is a side elevation view of the device as shown in FIG. 2;

FIG. 4 is a schematic view of the inventive safety catch for the jack, as applied to an automotive floor jack that is shown in phantom and in a raised position; and

FIG. 5 is a similar view, as shown in FIG. 4, with the safety catch and the jack in a released position.

Similar reference characters indicate corresponding parts and features, throughout the several views. More particularly, the character 10 identifies a horizontal tubular or sleeve bearing, for lateral installation into the body of a conventional hydraulic automobile floor jack, shown generally at l l, in FIGS. 4 and 5. The tubular bearing is equipped with a pair of perpendicularly extending arms 12, which may be attached to the tube 10, at the joints 13, in any efficient manner, such as by welding, for example. These arms 12 hingedlysupport a lJ-shaped channel member 14 at a pair of pivot points 15, by means of pins or in any other convenient, and efficient manner.

A vertically disposed plate 17 is attached'to the tubular bearing 10 at point 18, as by weldingoThe plate 17 supportsa compression spring 19, by means of a bolt 20. The vertical plate 17 is here shown as having a release cord, chain, rod, or the like, 21 attached at point 22.

The purpose and function of the device is shown in FIGS. 4 and 5. The channel 14(see FIG. 4), is pivoted on bearing 10A in shaft 10 and pin and 16 in pivot point 15 and placed into position when the jack compresses the spring 19 and lifts the auto into a'raised position. The jack includes a hydraulic cylinder 30, and telescoping shaft 31, connected to a linkage assembly 33 at 32. When the hydraulic fluid is pumped into cylinder 30, the shaft 31. extends to such linkage 32. When the channel 14 is raised,it partly surrounds the shaft 31 and props the linkage 33 against cylinder 30 to prevent retraction thereof. Thus, the auto will not lower if fluid leaks out of cylinder 30.

When the release. cord 21 is pulled as shown by the arrow (see FIG. 5), it pulls the plate 17 into an angularly downward position, thereby lowering the channel 14, and releasing the pressure on the spring 19. The jack 11 may now be lowered as shown in FIG. 5, by releasing the hydraulic fluid from the cylinder since the linkage 33 and cylinder 30 are no longer propped apart.

The safety catch device is simple in construction, and easy to apply to most rolling hydraulic auto jacks. When the jack is raised, spring 19 automatically applies the safety catch. By pulling the cord 21, the jack may be released.

Although I have shown a specific and detailed construction of the device, many changes may be made in the various parts without effecting their operativeness. Therefore, I reserve the rights to make such changes as I may deem necessary or convenient. The claims should be construed to cover all equivalents which do not depart from the spirit of my invention.

I claim: a

1. A rolling auto jack,

said auto jack comprising:

a hydraulic cylinder,

a shaft telescopingly movable in said cylinder,

linkage means connected to the end of said shaft for translating shaft motion into raised and lowered jack positions, i

a safety means to prevent retraction of said shaft into said cylinder in the event of malfunctioning of said cylinder, 7

said safety means comprising a propping block,

said proppingblock having a propping position preventing retraction of said shaft and a non-propping position enabling retraction of the shaft,

said propping block in the propping position being contiguous to said shaft between said linkage means and said cylinder,

said propping block normally in the non-propping position removed from said shaft when said shaft is in the retracted position, and spring means for automatically forcing said block intothe propping position responsive to an extension of said shaft. 2. The catchof claim 1 and means for manually releasing said catch by moving it to a non-propping positIOI'l'. V i

3. A rolling auto jack, said jack comprising a hydraulic cylinder, 3 a shaft telescopingly moving in said cylinder, linkage means connected to the end of said shaft for translating shaft motion to raised and lowered shaft positions, p a safety catch to prevent retraction of said shaft into said cylinder, said safety catch comprising a propping block fitting adjacent said shaft between said linkage means and said cylinder, and said propping block comprising a U-shaped channel partly surrounding said shaft when in said propping position. i a 4. The catch of claim 3 and a pair'of arms pivotally attached to said U-shaped channel and rigidly attached to a tubular bearing fitting into the frame of said jack.

5. The catch .of claim 4 and a tab attached to said eras-11*

Claims

1. A rolling auto jack, said auto jack comprising: a hydraulic cylinder, a shaft telescopingly movable in said cylinder, linkage means connected to the end of said shaft for translating shaft motion into raised and lowered jack positions, a safety means to prevent retraction of said shaft into said cylinder in the event of malfunctioning of said cylinder, said safety means comprising a propping block, said propping block having a propping position preventing retraction of said shaft and a non-propping position enabling retraction of the shaft, said propping block in the propping position being contiguous to said shaft between said linkage means and said cylinder, said propping block normally in the non-propping position removed from said shaft when said shaft is in the retracted position, and spring means for automatically forcing said block into the propping position responsive to an extension of said shaft.

2. The catch of claim 1 and means for manually releasing said catch by moving it to a non-propping position.

3. A rolling auto jack, said jack comprising a hydraulic cylinder, a shaft telescopingly moving in said cylinder, linkage means connected to the end of said shaft for translating shaft motion to raised and lowered shaft positions, a safety catch to prevent retraction of said shaft into said cylinder, said safety catch comprising a propping block fitting adjacent said shaft between said linkage means and said cylinder, and said propping block comprising a U-shaped channel partly surrounding said shaft when in said propping position.

4. The catch of claim 3 and a pair of arms pivotally attached to said U-shaped channel and rigidly attached to a tubular bearing fitting into the frame of said jack.

5. The catch of claim 4 and a tab attached to said bearing, and said release means comprises means for moving said tab to rotate said bearing and move said block.