US243922A - Ratchet-lever for lifting-jacks - Google Patents

Description

v J. s. KIRKWOOD. i RATGHET LEVER FOR LIFTING JAG-KS &c. No. 243,922.

.(N o Model.) I

Patented July '5, 1881.

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WITNESSES ATTORNEKY 2.

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UNITED STATES PATENT ()FFICE.

JOSEPH S. KIRKWOOD, OF MCKEESPORT, PENNSYLVANIA.

RATCHET-LEVER FOR LlFTlNG-JACKS, 800.

SPECIFICATION forming part of Letters Patent No. 243,922, dated July 5, 1881.

Application filed May 2, 1881. (No model.)

To all whom it may concern Be it known that I, JOSEPH S. KIRKWOOD, of McKeesport, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Ratchet- Levers for Lifting-Jacks, &c.; and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same, reference being bad to the accompanying drawing, which forms a part of this specification.

This invention relates to a novel ratchet-lever for various purposes, but having especial reference to use with that class of lifting-jacks in which a toothed pinion, when revolved, lifts a sliding toothed rack, the pinion being revolved by a suitable lever.

My invention consists in the novel construction and combination of parts of a lever adapted to the above purpose, substantially as hereinafter described and claimed.

In the drawing the figure is an isometrical perspective, illustrating my invention as applied to one of the above-described class of liftin g-j acks.

A designates the vertical toothed rack, guided in the standards B B, and G is the toothed pinion or drum, whose revolution lifts the rack A, and which it is desired to revolve with a lever.

D is a detent taking into the rack A by gravity to hold the rack while retracting the lever for a fresh hold on the pinion.

On the square journals of drum 0 are two similar ratchets, E E, as shown.

To construct the lever I proceed as follows: The lever is bifurcated, being cast in two parts, the two arms (Ht being respectively journaled on the spindle b of the drum 0, outside the ratchets E, as shown. Arms a a turn inwardly and meet to form the handle-socket c, as shown, in which a large wooden handle is intended to be fitted. In this arrangement the lever a. a c is free to be oscillated up and down. A T- shaped lever, Gr, having the lateral trunnions d, is let into the frame a a before fitting together. At points to the rear of trunnions d on lever G are pivoted the two similar pawls h, as shown, pawls h being free to move in the respective planes of the ratchets E and engage with them. According to the position of lever G with reference to hand-lever a a c the pawls It can or cannot engage the ratchets E, for lever G, rotating on trunnions d, moves the pivotal points of pawls h to or from the drum 0. If too close to the drum, the pawls cannot engage the teeth of ratchets E. As constructed, the pawls h will properly engage the ratchets E when the lever G is brought down against lever a a c, and they are held there by the sliding catch 1 which moves to and fro in a recess cast in the two upper faces of socket c c, as shown. The parts being in this position, and the pawls prevented by a suitable back-stop from getting beyond a vertical position, so that they will always gravitate toward the ratchets when the lever a a c is elevated, the pawls it pass back over the teeth of ratchets E as far as the movement of the lever will permit; then on the reverse motion of the lever the pawls engage the ratchets E and revolve them and drum G, thus lifting the rack-bar A, which is then retained during the retraction of lever a a c by means of the detent D, whose flanges 7c are supported upon the standards B B, as shown, and so on till it is desired to lower the rack A quickly. To do this the lever a a c is depressed slightly till the strain upon detent D is released and it is thrown out of engagement. The whole strain is now upon the pawls h and the lever. The catch t is now withdrawn, which frees the lever G, and this instantly flies up, bringing the pivotal points of pawls h toward the drum (3, where they are unable to engage the ratchets, and consequently the rack A is free to descend as far as it can go.

The construction is cheap, simple, and effective, and cannot get out of order.

I claim as my invention- In combination with the ratchets E of a liftin g-jack or similar device, the bifurcated lever to a 0, having the lever G pivoted therein, carrying the pivoted pawls h, arranged and op- 'erating substantially as described.

In testimony that I claim the foregoing as my own I have hereto affixed my signature in presence of two witnesses.

JOS. S. KIRKWOOD.

Witnesses:

T. J. McTIeHE, F. J. PATTERSON.

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