US13835A - Francis drew - Google Patents

Description

unirse sii-Arnie PATENT onrrcn. FRANCIS DREW, OF SOUTH BOSTON, MASSACHUSETTS, ASSIGNOR T0 F. DREW AND' S. S.

LIFTING-JACK.

Specification of Letters Patent No. 13,835, dated November 20, 1855.

To all whom it 'may concern:

Be it known that I, FRANCIS DREW, of South Boston, in the county of Suffolk and State of Massachusetts, have invented Cer tain new and useful Improvements in Lifting Jacks, of which the following is a full, clear, and exact description, reference being had to the annexed drawings, making part of this specification, in which- Figure l is a side view, Fig. 2, a front view and Fig. 3 a plan.

To enable others skilled in the art to understand my invention I will proceed to describe the manner in which I have carried it out.

In the accompanying drawings A, is the body of the jack, B, the follower' which is operated in'the following manner: C, C, are pinions upon the shafts D, D, which engage with the teeth E, E, upon the follower. F, F, are sockets which revolve freely upon the shafts D, D, and are connected together by the arms I-I, H, so as to vibrate together but in opposite directions. They are operated by the levers Gf G', and carry the pawls I, I. These pawls engage with the ratchet wheels K, K', upon the shaft D, D', and secured thereto. As

one of these levers (G) is depressed its pawl I, operates the ratchet wheel K, which revolves the wheel C, by which means the follower is raised at the same time by means of the connections H, H, the lever G is raised. vWhen this lever is depressed fits pawl I, revolves the ratchet wheel K, 'and the follower is again raised. Thus by operating the levers the follower is cont-inually raised, the retaining pawls m, engaging with the racks l?, P, and preventing it from returning. When it is required to drop the follower it is onlv necessary to raise the pawls m, x', I, I, and it descends by its own weight.

It is evident that this jack may be operated much more rapidly than the ordinary screw jack, and also that it may be used in many positions where it would not be possible to employ a jack operated by a revolving lever.

Vhat I claim as my invention and desire 'to secure by Letters Patent is- The within described jack consisting of the sockets F, F', with their connecting arms H, H, and pawls I I in combination with the ratchet wheels K, K, and cog wheels C, C', arranged and operating in the manner set forth.

FRANCIS DREW.

Witnesses:

SAM. COOPER, THos. L. GLovER.

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