US1424390A - Lifting jack - Google Patents

Description

W. C. YARMOLAITIS.

LIFTING JACK.

APPLICATION FILED JULY 24. 1920.-

1,424,39. I Patented Aug. 1,1922,

enrr

earner LIF'IING- JACK.

anson.

Application filed July 24,

To all whom it may concern:

lle it known that l, lViLLniM C. Ynmro- LArris, a, citizen of Lithuania, residing at Cleveland, in the county of Uuyahoga and State of Ohio, have invented certain new and useful. Improvements in Lifting Jacks, of which the following is a specification.

This invention relates to lifting jacks, and has for its j irincipal object to provide a lifting jack for use in connection with automobiles, which raises or lowers a load step by step by operating a hand lever up and down, the change from raising to lowering being ellected by simple and easily operated means.

rinother object of this invention is to provide a lifting jack of said character, which is so designed that the parts thereof are inexpensive to manufacture and assemble.

vi' ith the above and other objects in view as will be readily understood, the invention will be hereii'iafter fully described as illustrated in the acconnmnying drawings, and the novel features thereof will be distinctly pointed out in the appended claims.

In the drawings similar characters of reference are used to designate corresponding parts.

Figure 1 is a side elevation of a lifting jack constructed in accordance with my invention the parts being in position for lifting a load,

Fig. 2 illustrates the positionsof the parts after the operating lever has been forced down, and the revr sing lever has been pushed down for lowering the load,

Fig. illustrates the position of the parts at the commencement of the lowering of the load, the holding pawl being out of engagenient with'the lifting bar,

Fig. 4: illustrates the pOSltlUlLOjf the parts a 'r'ter the operating lever has been pulled up and the lifting bar lowered thereby,

Fig. is a sectional elevation taken on line of F 3,

Fig. (3 is a perspective view of the reversing lever. and

Fi 7 is a view showing the working pawl and holding pawl pivoted to the operating lever.

lli-iferring to the drawings, 1 represents a hollow standard having a base 2, and at the front side of the standard near its upper end is a housing 3. A lift bar 4 having a head 5 and ratchet teeth 6 in its front edge is movablv supported in said hollow standard.

The front side of the housing 3 is cut away Specification of Letters Patent.

Patented Aug. 1, 1922.

1920. Serial No. 398,614.

at '7 for receiving the bifurcated end 8 of an operating lever 9 which is pivoted between the sides of the housing by a pin 10. To the inner part and between the sides of the bifurcated end 8 of the operating lever 9 is pivoted a working pawl 11 by means of a pin 12, and a holding pawl 13 is pivoted therebetween on the pin 10. The working pawl 11 and the holding pawl 13 carry laterally extending pins 1 1 and 15 respectively, and suitable springs 16 and 17 engage said pins for the purpose of causing said pawls to engage the ratchet teeth 6 of the lifting bar l. The spring 16 is coiled upon the pivot pin 12, and its free end 18 rests in the operating lever at 19, and the spring 17 is coiled upon the pivot pin 10, and its free end 20 also rests within the operating lever at 19. lly pushing downwardly upon the operating lever 9, Figs. 1 and 2, power is transmitted to the working pawl 11, which forces the lift bar at upwardly, and the holding pawl 13 prevents the falling of the lift bar upon releasing the operating lever.

In order to lower the lift bar by theup and down movement of the operating lever, the mechanism 110w to be described is provided. It consists of a reversing bar 21, which is pivoted on the pin 10, and its upper beveled end is recessed at 23 thereby leaving a finger 2a. A suitable spring 25, coiled upon the pivot pin 10, with one of its arms 26 bent under the reversing bar 21, and its other free arm 27 restingupon a ledge 28 of the housing 3, is adapted to force the cam bar up against the lateral pin 15 of the holding pawl 13. By pushing the operating lever downwardly to raise the lift bar 4: sufficiently to release the holding pawl 13, Fig. 3, the spring25 will overcome. the action of the spring 17, and throw the holding pawl 13, out of engagement with the lift bar, which will permit thelowering of the lift bar upon the raising of the operating lever. As the operating lever is raised, the working pawl 11 moves downwardly and its lateral pin 14 engages the beveled end 22 of the reversing bar 21. thereby moving the cam bar away from the lateral pin 15 of the holding pawl 13 and allowing the spring 17 to force the holding pawl into engagement with the teeth of the lift bar 4:. hen the working pawl 11 was moving downwardly, its lateral pin la first engaged the beveled end 22 of the cam bar 21, and then entered the recess 23 thereof. At the movement the load of the lift bar 4 is supported by the holding pawl 13, Fig. 4, the'action of the spring 25 overcomes the action of the spring 16, and the reversing bar 21, by exerting pressure against the lateral pin it, forces the working pawl 11 out of engagement with the lift bar. By pushing downwardly upon the operating lever. the working pawl 11 is moved up wardly, and as soon as its lateral pin 14: passes above the finger 2a of the cam bar 21, it is forced by the spring 16 into engagement=with the teeth of the lift bar. Thus the load is lowered by being shifted from the holding pawl 13 to the working pawl 11. To be able to raise a load as first described, it is necessary to hold the reversing bar 21 out of engagement with the lateral pin 15 of the holding pawl 13, and for this purpose, a

' reversing lever 29, Fig. l, is pivoted at 30 to the reversing bar, which is cut away at 31 to receive the same. The lower end of the reversing lever 29 serves as a cam 32 for engaging the bottom 33 of the housing 3 to force the reversing bar 21 out of engagement with the lateral pin 15 against the action of the spring 25, and hold it in said position. lVhen the reversing lever 29 is in its up position as in Fig. 1, the load may be lifted, and when in its down position as in Fig. 2, the load may be lowered.

Having fully described my invention, what I claim is: V

1. In a lifting ack, the combination of a standard, a lift bar movably supported in the standard, a holding pawl pivoted to the standard, an operating lever pivoted to the standard, a working pawl pivoted to the operating lever, springs tending to force the holding pawl and working pawl into engagement with the lift bar, means for forcing the holding pawl and the working pawl alternately out of engagement with the lift bar as the operating lever is moved, and means for moving said means out of action including a lever having a cam adapted to engage said standard for holding said lever in a set position, substantially as described.

2. In a lifting jack, the combination of a standard, a lift bar movably supported in the standard, a holding pawl. pivoted to the standard, an operating lever pivoted to the standard, a working pawl pivoted to the operating lever, springs tending to force the holding pawl and working pawl into engagement with the lift bar, means for forcing the holding pawl and the working pawl alternately out ofengagement with the lift bar as the operating lever is moved, a reversing lever for moving and holding said means out of action, and the reversing lever having a cam adapted to engage said standard for holding said reversing lever in a set position, substantially as described.

3. In a lifting jack, the combination of a standard, a lift bar movably supported in the standard, a holding pawl pivoted to the standard, an operating lever pivoted to the standard, a working pawl pivoted to the operating lever, springs tending to force the holding pawl and working pawl into engagement with the lift bar, a reversing bar pivoted to the standard, a spring tending to cause the reversing bar to force the holding pawl out of engagement with the lift bar, the working pawl having means for en gaging the reversing bar to overcome the action of its spring, the reversing bar having a recess for receiving said means of the working, pawl whereby the working pawl will he moved out of engagement with the lift bar, a reversing lever pivoted to the reversing bar, and the reversing lever having a cam adapted to engage said standard for moving the reversing bar out of action for holding said reversing lever in a set position, substantially as described.

4. In a lifting jack, the combination of a standard, a lift bar movably supported in the standard, a holding pawl pivoted to the standard, an operating lever pivoted to the standard, a working pawl pivoted to the operating lever, the holding pawl and the working pawl carrying lateral pins, springs coiled around. the pivots of said pawls and engaging said lateral pins for forcing the pawls into engagement with the lift bar, the free ends of said springs resting in the operating lever, a reversing bar pivoted to the standard, a spring coiled around the pivot of the reversing lever having one end under the reversing lever and its other end supported. by the standard for forcing the reversing lever against the lateral pin of the holding pawl to push it out of engagement with the lift bar, the lateral pin of the working pawl being adapted to engage the reversing bar to force it away from the lateral pin of the holding pawhthe reversing bar being provided with a recess for receiving the lateral pin of the working pawl whereby the working pawl will be moved out of engagement with the lift bar, a reversing lever pivoted to the reversing bar, a cam at the end of the reversing lever, and

the cam being adapted to engage said standard formoving the reversing bar out of action and holding it in a set position, substantially as described;

In testimon 1 whereof I affixmy signature.

WIL MM 0. YARMOLAITIS.

Images