GB1339596A - Hoisting device - Google Patents

Abstract

1339596 Hoists C H ARNOLD 3 Sept 1971 [4 Sept 1970] 41111/71 Headings B8B and B8M A hoisting device comprises a drum 10 provided with a plurality of peripheral grooves in planes at right angles to the drum axis, a hoisting rope 18, 19 wound with a plurality of parallel windings on the drum and a plurality of transfer rollers 21-26 spaced around the periphery of the drum for deflecting the rope from one groove to the adjacent groove, tension rollers 43-50 being provided interspaced with the deflecting rollers to press the rope into the drum grooves. The tensioned end 18 of the rope up which the hoist climbs, passes around the drum for 300 degrees whereat it is shunted by the roller 21 into the adjacent groove for a further 300 degrees and so on until the slack end 19 of the rope passes from the hoist, the rope being guided to and from the drum by guides 85 and 73 which together with the transfer and tension rollers facilitate self reeving of the cable on the hoist. Each transfer roller has a contoured surface to accept the rope windings on the drum except in the area of the two particular drum grooves between which the rope is to be transferred where an enlarged flange on the roller engages the rope for transference, the roller being angled to facilitate the transfer. Flanges on the drum 10 restrict axial shift of the rollers. The tension rollers which are spring biased towards the drum 10 are contoured to accept the rope windings and are frictionally driven by the drum flanges. The drum 10 which is driven through worm gearing 3 and 4 may be provided with plastics inserts for recesses in the roots of the grooves and the groove diameters may be graduated across the drum. In the modification of Fig. 10 (not shown) the rope is guided on to the drum through a housing having a stepped enlarged bore whereby excessive inherent curl in the rope end catches on the step and is prevented from entry to the hoist for reeving. In the embodiment of Fig. 9 (not shown) the hoist is secured to stationary structure and each of the rope extends to support a load, cage or counterweight. In a modification, Figs. 11, 12, 13 (not shown) all the transfer rollers are positioned over the half of the diameter of the drum to and from which the rope extends and the rollers are associated with a pair of cables connected to either a safety cut out for the hoist motor or a rope grip brake, whereby faulty hoist cable passing beneath the rollers will cause a stoppage of the hoist.