US284875A

US284875A - Chaeles l

Info

Publication number: US284875A
Authority: US
Publication date: 1883-09-11
Anticipated expiration: 1900-09-11

Description

(No Model.)

. O. L. MARTIN.

LIFTING JACK.

No. 284,875. Patented Sept. 11, I883.

W/T/VESSES Afforney NITED STATES CHARLES L. MARTIN, OF GHABLOTTESVILLE, VIRGINIA.

LlFTlNG-JACK.

SPECIFICATION forming part of Letters Patent No. 284,875, dated September 11, 1883.

Applieation filed June 533, 1883. (No model.) I

To all whom it may concern:

Be it known that I, CHARLES L. MARTIN, a citizen of the United States, residing at Oharlottesville, inthe county of Albemarle and State of Virginia, have invented certain new and useful Improvements in Lifting- Jacks, of which the following is a specification, referencebeing had therein to the accompanying drawings.

My invention relates to lifting-jacks; and it consists in the parts which will be hereinafter specified, and pointed out in the claims.

In the accompanying drawings, Figure 1 represents a perspective view of my device, and Fig. 2 is a central vertical section.

Like letters indicate like parts in the views.

A is the vertically-adjustable weight-bar, and A is the bevel inner part thereof, adapted to rest on the upper side of the lever.

B is a cross-block on the inner under side of bar A. Said cross-block is provided with a stud or stop-piece, B, to limit the upward movement of the bar.

O is the opening in the bar between the block B and the bevel-point A.

D shows the ratchets on the bar A, and E is the pawl, pivoted at E between the framepieces F F. The greater part or weight of the pawl lies inside of the pivot, whereby said pawl is given an inward tendency, thereby causing it to engage the teeth automatically without the aid of a spring. The pawl can be disengaged by pushing in on the outer projections. v

G represents the side frame-pieces, into which rounds H are secured.

G is a strip on the rear part of the jack to prevent the inner end of the lever from passing through when it is inserted to engage the round H.

I I are cross-blocks between the framepieces G. J is a block between the framepieces F. K is also a block between said pleces.

The pawl E is provided with an inner shoulder, (shown in Fig. 2,) which rests upon the upper side of block K when the said pawl is engaged with the ratchets D and weight applied to the bar A. By this means when the weight is resting upon the bar the strain is removed from the pivot E. The block K also serves as a stop to engage the stud B, and thereby arrest the upward movement of the bar A beyond the point.

The letter L represents the lever.

Having thus fully set forth the mechanical construction of my invention, I will now proceed to describe its mode of operation.

. The lever L is removable from the rounds H, and may also be wholly withdrawn from the casing. By placing the upper part of the weight-bar A under the object to be hited, and then inserting the notched end of the lever through the opening 0 and engaging one of the rounds, raising the handle of the lever will elevate the bar A and the weight thereon. The pawl E will engage the ratchets D when the bar A is raised and prevent said bar from descending. It will be observed that the fulcrum of the lever is forward of the weight tobe lifted-that is to say, the weight rests upon the lever back oi the fulcrum. Therefore the weight is directly lifted by the lever instead of being pressed up, which is the reverse operation. As the bar A is elevated, the lever may be engaged with the next succeeding round, and thus continue the upward movement of the bar and lever until the weight has been elevated to a desired height.

In Fig. 1 of the drawings two cross out side blocks, M M, are shown for uniting theframe-pieces F G. I do not wish, however, to confine myself to such construction, but prefer to substitute a solid plate to cover the whole of the side shown in said figure.

Having thus described my invention, I claim as new and desireto secure by Letters Iatent- 1. In a lifting-jack, the notched bar A, provided with opening 0, in combination with the frame provided with the weighted pawl having inside shoulder, as specified, block K, rounds H, and lever L, substantially as described, and for the purposes set forth.

2. In a lifting-jack, the notched bar A, provided with opening G and stud B, in combination with the frame provided with rounds I-I, block K, pawl E, and the lever L, substantially as described, and for the purposes set forth.

In testimony whereof I affix my signature in presence of two witnesses.

CHARLES L. MARTIN.

Witnesses W. E. Win-manna, F. 0. MCOLEARY.