SAFETY ELEVATORS FOR LIFTING A PERSON WITH OR WITHOUT A LOAD

摘要

1,196,764. Platform elevators; lifts; jacks. C. J. P. LEBRE. 14 July, 1967 [16 July, 1966; 28 July, 1966; 22 Oct., 1966], No. 32510/67. Headings B8H, B8L and B8J. A cage 5 provided with a load platform 85 is raised on guides 3, 4 by reciprocation of pedals 11, 12 which are coupled to clamp blocks 27, 28, 47, 48 on the guides and cause the clamp blocks to move up the guides step by step. The clamp blocks comprise a wedge-shaped shoe 56 which is urged upwardly in a housing 53 by a spring 61, whereby downward movement of the block is prevented. A further shoe 63 is formed with a projection forming a piston in a chamber 65. The chambers of the upper pair of clamp blocks are interconnected via a pipeline 66a and those of the lower pair are interconnected via a pipeline 66b and communicate respectively with chambers 70a, 70b in a cylinder 71, on the cage 5. The size of the chambers 70a, 70b is varied by a hand lever 76, pivoted at 77 and engaging pistons 75a, 75b. During upward movement of the cage, with the lever 76 in its upper position, a maximum fluid pressure is exerted on the jaws, and reciprocation of the pedals 11, 12 moves the clamp blocks step by step up the guides by means of linkages, Fig. 1. On moving the hand lever 76 downwardly, the pressure exerted on the clamp blocks is reduced allowing the clamp blocks and the cage to move downwardly at a controlled speed.