US463385A - Lifting-jack - Google Patents

Description

(No Model.)

' P. GRIFFIN.

LIETING JACK. 110.463,385. Patented Nov. 17, 1891.

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UNTTED STATES PATENT OFFICE.

PETER GRIFFIN, OF DAYTON, OHIO.

LlFTlNG-JACK.

SPECIFICATION forming part of Letters Patent No. 463,385, dated November 17, 1891.

Application tiled June 15, 1891. Serial No. 396,290. (No model.)

To all whom, t may concern:

Be it known that I, PETER GRIFFIN, a citizen ofthe United States, residing at Dayton, in the county of Montgomery and State of Ohio, have invented certain new and useful Improvements in Lifting-Jacks, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to certain new and useful improvements in lifting-jacks.

My improvements have reference to an operating-pawl and an eccentric-lever having means for adjusting its throw; have reference to combining with a vertically-moving follower a lifting-screw mounted in the follower; have reference to making the follower of such shape in cross-section that it will present a projecting corner or angle adapted to enter places which the broad flat side would not enter, whereby objects may be reached which otherwise would be inaccessible to the follower, and have reference to certain features of construction in the base and guides.

In the accompanying drawings, forming a part of this specification, and on which like reference-letters indicate corresponding parts, Figure l represents a partial side elevation and a partial sectional viewof myimproved liftingjack; Fig. 2, a plan view; Fig. 3, aperspective View of the follower in detail; andFig. 4, a plan view of the base, guides, and follower with the lifting-screw, detent, and operatinglever removed.

The letter A designates the base -plate, upon which is cast or otherwise secured guides B, whose arrangement and position are preferably that shown in Figs. 2 and 4, so that the follower C will have a corner D standing opposite the operating-lever, whereby7 a projection or edge is provided capable of reaching into places which would be inaccessible to the liat side of the follower. By this posi'- tion and arrangement the device is rendered useful in places and at times when otherwise it would not be available to lift objects access -to which is circumscribed.

The guides constitute braces at their lower-` ends in connection with web H and l.

The lower end of the follower is provided l with a stout arm J, adapted to extend under objects to be lifted, as when such objects are too low to get the follower under them. By this means such objects may be lifted until their altitude will admit of placing the follower under them, when they may be further lifted aswell by the vertical adjustment of the follower as by the projection upward of the screw K by rotating it through one or more levers L, shown in dotted lines, and adaptedto enter holes L in the head M. This screw K is fitted to a screw-threaded opening of suitable length in the follower. Vhen an object difficult of access is to be lifted by the corner of the follower, the screw may be run up until its head is out of the way, or may be removed altogether.

The web F is provided with ratchet-teeth O, with which engage a double-pointed detent P and a double-pointed pawl Q. The detent is pivoted upon a pin R, carried by the wings E, and is provided with a thumb-piece S, and is pressed against the ratchet-teeth by a spring T. The pawl is held in engagement with the teeth by a similar spring U and has a hand-piece V, and is mounted upon the eccentric VV of an eccentric-lever S. The eccentric has a plurality of holes Y Y of dit'- ferent eccentricity and adapted to be mounted upon a pin Z, carried by wings E. The

eccentric-lever elevates and lowers the pawl t Q with a leverage and with a length of stroke varying with the particular hole Y or Y in which the pin is placed. If a quick movement is desired, the lever is adjusted to receive the pin Z in the more remote hole in the eccentric. If a slower movement is required, the pin will be placed in a hole nearer to the center. Thus the follower may be actuated with a quick movement and at reduced leverage, or with a slower movement and at an increased leverage without change of instru- .mentalities the same devices being used in each case with a mere change of the pin from one hole to another.

It' .the object to be lifted becomes for some reason too much for the available power that can 'be applied to the eccentric-lever, or if that object needs to be lifted' to a point intermediate of the position reached by the follower when moved the height of the thick- TOC ness of one ratchet-tooth, or if that object must be lifted higher than the range of 1novenient of the follower will aceomplish,tl1en resort may be had to the screw K,-wl1iel1, it will be seen, can be operated with less resistance t0 the efforts applied to it than incident to the Vertical movement of the follower.

The operation and advantages of my invention will be understood from the above.

Having thus fully described my invention, whatI claim as new, and desire to secure by Letters Patent, is-

1. The combination, with a base and guides and wings, of a follower mounted in said guides and a lifting-screw mounted in the follower, a. pawl and detent engaging the fol- PETER GRIFFIN. lVitnesses:

EDWARD CURRAN, Il. A. HUNTER.

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