GB1224042A - Improvements in or relating to winding gear in hoists, cranes, lifts and the like - Google Patents

Abstract

1,224,042. Winches. LANGDALE ENG. CO. Ltd. 27 May, 1969 [30 May, 1968], No. 25921/68. Heading B8B. [Also in Division F2] A winding apparatus comprises a winch drum 1 having a brake drum 31 secured to each end, which drums 31 are permanently urged towards fixed brake shows 32 by springs 14 acting on the winch drum 1, the latter being hydraulically displaceable to move the brake drums clear of the brake shoes as the winch drum is hydraulically driven. The winch drum driving and displacing means form part of a common hydraulic circuit such that the winch drum is automatically braked if the drive thereto fails. The winch drum shaft 2 is mounted between a pair of lever arms 3 pivotally mounted on side-plates 5 about an axis 4A eccentric to the axis 2A of the shaft 2, whereupon displacement of extensions 7 of the levers 3 cause the displacement of the drum. Each lever 3 is biased by a spring 14 into the position in which the drum is braked, and is displaceable against this spring pressure by the rod 8 of an hydraulic ram 20, 21, 22, when pressurized. The ram includes two pistons 21, 22 spring-biased apart, and pressurized fluid is supplied thereto through ports 26 or 27 depending on whether the drum is being driven forward or in reverse, the ram being extended to release the braking in both cases. The ram may be double acting to assist in the braking action on the drum. The drum drive comprises two reversible hydraulic motors mounted inside the drum and one or both may be selectively operated. In another embodiment, the winch drum mounted on the arm is partially or wholly counterbalanced. In a further embodiment the drum is driven by electric motors and is displaced by solenoids powered from the motor circuit.