GB478740A - Improvements in hydraulic jacks - Google Patents

Abstract

478,740. Lifting-jacks. EVERSURE ACCESSORIES, Ltd., and VENNER, D. J. V. July 27, 1936, No. 20683. [Class 78 (iii)] The pump handle 4 of a fluid-pressure lifting- jack oscillates about a fixed spindle 7, and a slide 23 is movable endwise on the spindle to open a release valve for lowering by actuation of a control on the handle, the oscillation of the handle 4 having no action on the slide 23. As shown, the slide 23 is mounted on the spindle 7 within a housing 16 between side flanges 6 of the base of the handle 4. A pinion 24 at the lower end of a shaft 25 extending through the handle 4 from a rotatable control cap 27 at its upper end, meshes with annular teeth on the slide 23. When the cap 27 is turned, the slide 23 moves endwise and its bevelled nose 22 thrusts out a rod 21 which operates a lever 19 and a push-rod 43 for thrusting the release valve 34 off its seating. A foot lever 8 is pivoted at 10 to the base of the handle 4, and is connected by a link 11 to the pump plunger 12 which can be actuated either by the foot lever whilst the handle is stationary, or by the handle which carries the foot lever with it. A spring-retracted plunger mounted on the base of the handle engages with slots in a quadrant shaped end 45 of the frame 1 to ,lock the handle in an adjusted position. Rotation of a finger lever 48 on the handle depresses a push-rod 47 which disengages the plunger to release the handle. The lifting element comprises a pivoted lever 2 actuated by a cylinder 3 working over an oil reservoir cylinder 29 in which a valve casting 28 and the barrel 31 of the pump are provided. The apparatus is mounted between the side flanges of an inverted channel frame 1 fitted with a pair of wheels at the front and a pair of castors at the rear.