US144977A

US144977A - Improvement in lifting-jacks

Info

Publication number: US144977A
Authority: US
Publication date: 1873-11-25
Anticipated expiration: 1890-11-25

Description

UNITED STATES PATENT OEEIoEc JOHN T. HAMILTON, OF BOONE COUNTY, AND EZRA F. OONNER, OF DEOATUR, INDIANA 5 SAID GONNER ASSIGNOR TO SAID HAMILTON.

IMPROVEMENT IN LIFTING-JACKS.

Specification forming part of Letters Patent No. 144,977, dated November 25, 1873 application tiled September 24, 1873.

To all whom t may concern: A

Be it known that we, Jol-IN T. HAMILTON, of Boone county, and EZRA F. CONNER, of Decatur, in the State of Indiana, have invented certain new and useful Improvements in Lifting-Jack; and do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon, making a part of this -the machine, all as more fully hereinafter set vforth and claimed.

In order to enable others skilled in the art to which our invention appertains to make and use the same, we will now proceed to describe its construction and operation, referring to the annexed drawing, which represents a perspective view of our improved lifting-jack.

A A represent two legs, pivoted together at their upper ends by a bolt, a. This bolt passes through and pivots the lever B between the two legs A A, as shown. To the lever B is hinged a bar, C, by means of two curved plates, which are iirmly fastened, one on each side, at the end of the bar C, and the projecting ends of said plates are pivoted to the lever B, one on each side thereof. These curved plates guide the bar C properly while depressing the lever, and add strength to the machine.

The bar C is provided with a series of ratchetteeth, b b, cut in its under side, and passes in between the legs A A. D represents a rod, one end of which is attached to the bolt a on one side of the machine, and the lower end of said rod is bent at right angle and fastened by a screw, d, to the front side of the leg on the other side of the machine. The ratchet-bar O passes between this leg and the rod D, and the ratchet-teeth b b catch on the horizontal part of said rod, holding the lever in position after the article has been raised by the same.

In the patent above referred to, a short rod was used with both ends bent at right angles and fastened in one leg of the machine. This arrangement threw the whole strain from the article lifted through the ratchet-bar to one side of the machine, and made it difficult to y handle, and liable to tip over. By our present arrangement of the rod D, it will be seen that the strain is equal on both sides, thus steadying and strengthening the machine.

Having thus fully described our invention, what we claim as new, and desire to secure by Letters Patent, is-

' In a lifting-jack, the combination of the lever B, rod D, the ends of which are secured to the sides of the legs A A, and the rack-bar C, all substantially as and for the purposes set forth.

In testimony that we claim the lforegoing we have hereunto set our hands this 7th day of August, 1873.

JOHN T. HAMILTON. EZRA F. CONNER.

VVit-nesses FRANK M. DoWDEN, H. H. WooLLEv.