US278317A

US278317A - Lifting-jack

Info

Publication number: US278317A
Authority: US
Publication date: 1883-05-29
Anticipated expiration: 1900-05-29

Description

(No Model.) f

4 i J. DAWSON.-

` 'LIFTING JACK. No.' 278,317. PatentedvMay 29,1883.

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UNITED STATES PATENT FFICE.

JAMEs nAwsomoE sAN FEANcIsoo, CALIFORNIA.

LiF'rlNo-JACK.

SPECIFICATION forming part-of Letters Patent No. 278,317,dated May 29, 1883, l

Application filed February 5, 1883. (No model.)

To all whom it 'may concern: t

Be-itknown that I, JAMES DAWSON,` acitizen of the United States, residing at San Francisco, in the county of San Franciscoand State of California, have finvented certain new and useful Improvements in Lifting-Jacks; and I do declare the following to bea full, clear, and exact description of the invention, such as will enable others skilled in the art towhich it ap- .pertains to make and use the same, reference being had to theaccompanying drawings, and

IS `lifting-jacks,V and has for its object the moveto the letters and figures of reference marked thereon, hich form a part of this specification. l

My invention relates to improvements in ment of the lifting-bar usually employed in this class of devices by means `of cogs, gearwheels, and a crank-arm, the arrangement and operation of which will be more fully pointed out in the specification and claims.

Figure l is a side view of Inj-'improved lifting-jack, showing the side of casing, and by Fig; 2 is-a 1ony is a detail view of the bushings.

`A represents a metallic shell,` preferably cast rectangular in form,` and having a. chamber, a, of rectangular form,in its upper end,

and a. similar chamber a in its lower end.l

These chambers a and c are formed with angular apertures through their centers for the i j passage of the lifting-bar B,and are of sufcient width and depth to admit the friction-- rollers b and b. These rollers are formed to play loosely inside the chambers aand at', and are arranged to work against the sides of the chambers aand c andagainst the sides and rear of the lifting-bar B. The lifting-bar B is formed of metal, rectangular in shape, and has one edge serrated or grooved out crosswise to form teeth or cogs. `The purpose of "this formation, as will be more fully pointed out, is to gear with cog-wheels when moved np or down through the casing A by gearwheels andzpinions.

Each side of the casing is perforated at two points equidistantfromeach other,and on the d so outer side of the casing A these perforations l terminate in hollow projections c and c. In-

side these projections bushings ci and d' are placed to form the journals or bearings for the shafts G and C. These bushings d and d are formed to pass from the outer side of the projections c and c through to the inner sides of the casing A, and are held in place by setscrews e and c. The projections o and c are connected by stiffening-ribs f, the purpose of` mesh with and `operate the toothed rack-bar or lifting-barB.

0n the outer side of gear-wheel g, and near the'inside of casing A, is secured on shaft O a larger gear-wheel, g.

Shaft U is formed with an angular projection 0n its outer end for the reception of a crankarm or other device by which movement is communicated to said shaft. On the inside of the casing A, and directly opposite wheel g, is secured on shaft G a small gear-wheel, h, and of sufficient size to mesh or gear with wheel g.

The operation `is-as follows: Lifting-bar B is inserted through the apertures in chambers o anda through the casing with the teeth or cogs meshing with the teeth or cogs of gearwheel g, when power is applied to the shaft Cby means of its angular end, when the bar B is moved up or down,"as desired.

Having thus described my invention, what I desire to secure by Letters Patent isl small gear-wheel, g, the purpose of which is tof l. The combination of the casing A, having.

chambers a and a', holding friction-rollers b and b', the shafts C and C', bushings.` d and d', gear-wheels g, g', and h, with the liftingbar'B, substantially as shown and specified.

I 2. A lifting-jack provided with a casing, A, having chambers c and a', containing frictionrollers against which the lifting-bar moves when operated by shafts and gear-wheels, substantially as shown and specified.

3. Thebushingscl and d', formed as described,

and adapted to pass into Ihe projections cand c', and retained in place by set-screws, substantially as shown.

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

JAMES DAWSON.

Witnesses GEO. H. NoRnIs, J. J. KELLY.