US896725A - Lifting-jack. - Google Patents

Description

No. 896,725. PATENTED AUG. 25, 1908.

' J. F. HALE.

LIPTING JACK.

APPLICATION nun 1 113.11, 190a.

' Hill Summer arm ml nomus Plflll cm. wuslmnmn, n. c.

JOHN F. HALE, OF TONAWANDA, NEBRASKA.

LIFTING-J'ACK.

Specification of Letters Patent.

Patented Aug. 25, 1908.

Application filed February 11, 1908. Serial No. 415,381.

To all whom it may concern:

Be it known that I, JOHN F. HALE, citizen of the United States, residing at Tonawanda, in the county of Holt and State of Nebraska, have invented certain new and useful Improvements in Lifting-Jacks, of which the following is a specification.

The object of this invention is a simple, durable and efficient construction of an improved lifting jack whichmay be effectually operated with a minimum exertion of power, and which is arranged for operation in confined places and is therefore particularly adapted for use in raising houses or the like preparatory to moving them.

WVith this and other objects in view that will more fully appear as the description proceeds, the invention consists in certain constructions and arrangements of the parts that I shall hereinafter fully describe and claim.

For a full understanding of the invention and the merits thereof, reference is to be had to the following description and the accompanying drawing, in which:

Figure 1 is a perspective view of my improved lifting-jack; Fig. 2 is a vertical section thereof; and, Fig. 3 is a plan view.

Corresponding and like parts are referred to in the following description and indicated in all the views of the drawing by the same reference characters.

Referring to the drawing, the numeral 1 designates the base of my improved jack which is formed with a vertically extending threaded opening 2, an actuating screw 3 being mounted for longitudinal movement in such opening 2 with its upper end projecting therefrom as shown. The screw 3 is preferably reduced at its upper end to form an upwardly facing shoulder 4, and a head 5 is rotatably mounted on the reduced portion and rests against the shoulder 4 thereof, said head being designed to bear against the work.

In order to effect the convenient rotation of the screw and the consequent raising or lowering of the head, a ratchet 6 is keyed on the upper end of the screw just below the head, and said screw is preferably formed below the ratchet with an upwardly facing shoulder 7. A handle 8 is mounted to turn on the screw and in the present instance one and its other or free end is designed for engagement .with the ratchet, said pawl being held in such engagement with the ratchet by a spring finger 10, one end of which bears against the free end of the pawl and presses the latter inwardly. The other end of the spring finger is connected to the handle by a screw 11 passing through the latter, a thumb nut 12 being mounted on the extremity of the screw 11 and adapting the finger to be quickly adjusted'or swung back out of position. The pivot' point of the finger is so spaced from the pivot point of the pawl, that when the finger is turned back, the pawl may be swung around into reversed position, the finger being then moved against the pawl and the thumb nut 12 being tightened to hold the finger in such position.

From the above description in connection with theaccompanying drawing, it will be ap arent that I have provided an improved jac r-screw which may be operated by the reciprocation or partial rotation of the handle, and the operative parts of which may be quickly and conveniently reversed to cause the screw to move in the opposite direction. Having thus described the invention, what I claim is:

A jack-screw comprising a base formed with a vertically extending threaded opening, an actuating screw mounted in the opening and formed with upper and lower upwardly-facing shoulders, a head rotatably mounted on the upper shoulder of the screw, a ratchet rigidly secured on the screw below the head, a handle rotatably mounted on the lower shoulder of the screw below the ratchet, a pawl pivotally connected at one end to the handle, the other end of the pawl being designed for engagement with the ratchet, a spring finger bearing at one end against the free end of the pawl, a screw passing through the other end of the spring finger and the handle, and a thumb nut mounted on the extremity of the screw, the distance between the screw and the pivot point of the pawl being greater than the length of the. free end of the pawl as and for the purpose set forth.

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

B. P. NEHER. A

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