US388090A - Lifting-jack - Google Patents

Description

(No Model.)

W. TUCKER.

LIFTING JACK. No. 388,090; Patented Aug. 21, 1888.

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NITED STATES PATENT OFFICE.

WILLIAM TUCKER, OF DEOHERD, MISSOURI.

LIFTING=JAGK.

SPECIFICATION forming part of Letters Patent No. 388,090, dated August 21,1888.

Application filed April 26,1888. Serial No.2'71.939. (No model.)

To aZZ whom it may concern:

Be it known that I, WILLIAM TUCKER, a citizen of the United States, residing at Decherd, in the county of St. Clair and State of Missouri, have invented a new and useful Improvement in Lifting-Jacks, of which the following is a specification.

The invention relates to improvements in lifting-jacks; and it consists in the construction and novel combination of parts hereinafter described, illustrated in the drawings, and pointed out in the appended claim.

Figure l of the drawings represents a perspective view of a lifting-jack embodying the invention. Fig. 2 represents a central vertical section of the same, showing the eccentric lever raised in full lines and the same lowered in dotted lines. This view illustrates the manner in which the load, by pressing on the liftingblock, prevents the eccentric-lever from rais- 1ng.

Referring to the drawings by letter, A designates the frame or casing of the device, composed of the similar rectangular side plates, B B, and the base-block O. The two plates are connected in rear by the narrow strip 0, and in front, at top, by the short block D, having the downwardly and inwardly inclined outer edge,d, and at bottom by the larger block, E, having the upwardly and inwardly inclined outer edge, 0. These inclined edges, respectively, form the upper and lower stops for the eccentric-lever.

F is the liftingblock, of general rectangular shape, the lower part of which fits snugly in the open upper end of the casing, and has a horizontal lower edge. The vertical arm f of the lifting-block may have its upper end straight or concave, as desired. The liftingblock is preferably of steel.

G is the eccentric-disk, the shaft of which is journaled at g in the side plates, B, and which is provided with the lever H, that passes outward through the space between the inclined edges (1 and e. The edge of the eccentric is so arranged in relation to the lever H that when a load is lifted and the lever rests against theinclined edge e the point ofthe edge farthest from the eccentric-shaft is slightly in front of the center of the lower meetingedge of the lifting block, and consequently the pressure of the load will tend to rotate the eccentric forward, keeping the lever tight against the stopedge e, and the heavier the load the more strongly will the lever be held down. Thus when the load is once lifted it will be retained up, permitting the operator to use both hands for the necessary work.

The jack is used principally to lift wagons and other vehicles, but may obviously be used for various purposes ofthe kind.

Having described my invention, I claim- The improved lifting-jack herein described and shown, comprising the side plates, B B, the base-block 0, connecting the lower ends of the same, the vertical strip a, connecting the rear edges of the plates and closing the space between the same,'the block D at the upper front corners of the plates B B, having a downwardly and inwardly inclined lower edge, (I, the block E at the lower front corners of said plates, having an inwardly and upwardly inclined upper edge, e, the liftingblock F, sliding between the block D and the strip a, and the eccentricblock pivoted between the side plates below the lifting-block and the block D, and having a lever-handle projecting outwardly between the inclined edges of the blocks 1) and E, as specified.

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

\VILLIAM TUCKER.

Witnesses:

W. P. SHELDON, J OHN SEEvERs.

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