GB707312A - Improvements in lifts - Google Patents

Abstract

707,312. Platform lifts. SKYHI, Ltd., and STEAD, A. H. Jan. 12, 1953 [Oct. 12, 1951], No. 23822/51. Class 78 (3) The apparatus which is described as a garage lift, but is stated to be suitable for raising cinema organs, orchestra stalls or theatre stages, comprises a pair of wheel tracks 6, 6a slidable along vertical hollow pillars 7a-7d by a ram 13 secured to the underside of track 6 and having its cross head 14 connected to the ends of four cables which pass around a series of pulleys on the tracks to anchors at the tops of the pillars. The ram can be screw and nut operated, but as shown, it comprises a hydraulic piston and cylinder unit fed with fluid by a pump 19 which, together with the reservoir 21, is supported on the track 6a. The tracks, which have wheel chocks 9, are of channel section, the downwardly turned edges of which prevent damage to the ram and reservoir when the tracks are lowered. When the tracks reach their raised position, a spring latch 24 automatically engages a catch 26 on cross head 14 and so prevents movement of the tracks until the latch is raised by a hand lever 30. When so raised the latch is locked by a further, gravity-operated, latch (not shown) which renders the spring latch inoperative until the tracks have been fully lowered whereupon the gravity latch engages the ground and is rocked out of engagement with the spring latch. The tracks are equipped with guide rollers (not shown), which engage slots in the vertical pillars 7a-7d. In a modification (not shown), the tracks are laterally adjustable. In a further modification (not shown), a ram 13 which has a stroke less than the desired platform movement is connected to the platform through a system of multiplying pulleys.