GB247674A - Improvements in or relating to lifting jacks - Google Patents

Abstract

247,674. Newbould, O. B. Nov. 25, 1924. Jacks.-A portable jack comprises a base w on which is pivotally mounted a body portion which forms a ratchet-driven screw jack. The apparatus can be used as a tilting jack for raising a vehicle axle by backward or forward movement of the vehicle, and the body portion can be locked to the base in the vertical position for use as a screw jack. The base w is formed as a channel member with non-slipping undersurface, and is provided with a pivot pin t for the sides f of the body portion. The body-portion is held in the vertical position by a U-shaped bar n, pivoted to the sides f at n<1> and pulled down into slots w<1> in the base by a spring s. The bar n may be disengaged from the slot by means of a foot-lever p pivoted on the base w at p<1>, the spring s then pulling the body of the jack over into an inclined position as far as allowed by the adjustable bolt y. For safety, the member f may also be locked vertically by pegs p<2> inserted in holes in the base w wand sides f, these pegs also locking the foot lever p. When the sides f are raised from the inclined to the vertical position they abut against the pivot pin p'. When the locking bar n drops into the slots w<1> it engages a hammer v which strikes a bell o. A saddle member l is mounted between the sides f of the jack, its height being adjusted by means of setscrews e, g which may be inserted in any of a series of tapped holes in the members f, 1. The lifting-screw b works through a block a which is threaded externally for adjustment in the saddle l. The block d is held fast by a lock-nut c which is secured by a grub screw. The head a of the jack swivels on the top of the lifting-screw b. The lifting-screw is actuated in either direction by a ratchet handle h comprising a box member k in which are pivoted oppositely-acting pawls for engaging a fluted part at the lower end of the lifting-screw. One or other pawl is engaged. against the action of a spring, according to the position of a cam-ring v. The part h of the handle is telescopic, and is pivoted to the part k at m so that it can be turned vertically when not in use, or may be held in the horizontal position by a spring.