US767535A - Lifting-jack. - Google Patents

Description

No. 767,535. I PATENTED AUG. 16, 1904.

G. WIDEMAN.

LIPT-ING JACK.

APPLIOATION FILED NOV. 23, 1903.

N0 MODEL.

Wz'trz ease/54' [7 1/ 672 for? UNITED STATES Patented August 16, 1904.

PATENT OFFICE.

LIFTINGJACK.

SPECIFICATION formingpart of Letters Patent No. 767,535, dated August 16, 1904,

Application filed November 23, 1903. Serial No. 182,273. (No model.)

To all whmn it may concern:

Be it known that I, GUsTAvUs WVIDEMAN, a citizen of the United States, residing at Aurora, in the county of Kane and State of Illinois, have invented certain new and useful Improvements in Lifting-Jacks, of which the following is a specification.

My invention relates to improvements in that class of lifting-jaeksin which the liftingbar moves in vertical planes, power being applied thereto through a pivoted lever having a portion or connection that directly engages the said lifting-bar.

The primary object is to produce an effective and durable device with maximum economy in material and construction.

In the accompanying drawings, which form a part of this application, Figure 1 is a perspective view of a complete jack in inoperative position. Fig. 2 is a sectional view showing the relative positions of lifting-bar and lever when the former is being raised; and Fig. 3 is a view similar to Fig. 2, but showing the bar raised and locked in such position.

Referring to the details of the drawings, A represents a'rectangular piece of metal of 'sufficient size and suitable material to form a substantial base for the jack. Secured to the base by rivets Z) are two complementary metal plates B, which are connected with a space therebetween by rivets 6 have their lower edges flanged and perforated to admit therivets Z), and constitute the standard of the jack.

Slidably mounted between the plates B is the lifting-bar O, which in this instance is formed of two metal bars arranged with a slight space therebetween and suitably riveted together. In the rear edge of the bar so formed notches c are provided, which are adapted to engage the projecting ends of the pin (11, which is fixed in the rear side of the stirrup D. This stirrup is a piece of flat metal of the shape shown, is slidably arranged between the two parts of the bar (1, and is held in position by the frictional engagement of the pins d d with the notched and plain edges of said bar. The stirrup may be freely moved by hand to any point along the bar 0, and when released the rear pin d will be caused to enter one of the notches c by the dropping of the extended portion of the stirrup on the opposite side of the bar C.

Rigidly secured to the lower portion of the lifting-bar is a rack-bar G, the rounded teeth of which are formed along its rear edge. Below the teeth the bar is cut out to provide a concave portion, as at g, for a purpose to be described.

Pivoted on the standard B is a cam E, which is provided on a part of its periphery with teeth 6 and adjacent to the teeth with a convex. or rounded portion 0 to which latter portion the cam pivotal point is eccentric. This cam is preferably a malleable-iron casting and is formed with a socket a (shown by dotted lines,) into which is fitted and secured by rivets the lower end of the lever F, by which the cam is operated.

The stirrup being adjusted to the axle or other object to be raised and the lever being in its vertical position, depressing the lever will raise the lifting-bar through the engagement between the teeth of the bar and the cam, and upon continuing the downward movement of the lever the convex face 6 of the cam will be pressed against the concave face g of the rack-bar, thereby wedging the rack-bar between the rivets b and the cam and preventing the downward movement of the lifting-bar. The holding power of the cam is further augmented by the fact that the stress of the load carried by the lifting-bar is below the pivot-point of the cam when the lever is depressed the full limit.

It will be apparent that the rack-bar may be integral with the lifting-bar instead of a separate piece and that the cam may be without a socket and riveted to the lever or made integral therewith.

Novelty is not claimed for the stirrup, as it is understood to be a well-known feature of lifting-jacks in general use.

Having thus described my invention, what I claim as new, and desire to obtain by Letters Patent, is

1. In a lifting-jack, a standard having a slideway therein, a lifting-bar slidably mountalong one edge and with a concave portion, a

cam pivoted in said base and rovided with the rivets, said cam and liftin -bar having cop a u o acting and intermeshing portlons adapted to teeth adapted to mesh with the teethof the lifting-bar, and also provided with a convex portion adapted to engage the concave portion of the lifting-bar, and means for operating said cam.

2. In a lifting-jack, a standard composed of two plates secured together by rivets and with a space therebetween forming a slideway, a cam pivoted between said plates at one side of said slideway, and a lifting-bar ar' ranged in said slideway between the cam and lift the bar when the cam is operated, and also having portions in frictional contact adapted to lock the bar when the cam is operated in the manner described. I

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

GUSTAVUS WIDEMAN. Witnesses:

W. H. FITCH, F. BENJAMIN

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