GB499477A - Improvements in and relating to winches - Google Patents

Abstract

499,477. Winches. SCHAT, A.P. Sept. 5, 1938, No. 25888. Convention date, Sept. 3, 1937. [Class 78(v)] In a winch provided with a plurality of drums, or sets of drums, for handling a plurality of independent loads, the arrangement is such that all loads cannot be raised simultaneously but can be lowered simultaneously, and also that while one is being hoisted the others can be lowered or held. The Figure shows a winch for two loads which respectively are attached by cables to a pair of drums 5, 6 and 7, 8. The drums 5, 6 are driven in the same direction by a pinion 12 gearing with wheels 10, 11 on the drums, the pinion 12, together with a toothed wheel 17 being fixed on a shaft fitted with a centrifugal brake 14 turning in a casing 15 fitted with cooling ribs 16. A gear wheel 18 connects the wheel 17 to a pinion 19 loosely mounted on a shaft 20, but furnished with the male member of a clutch whereby it may be held to the shaft 20 by manipulation of a wheel 31. A reversible motor 4 drives a toothed wheel 34 loose on the shaft 20 but gripping the shaft, when rotated in one direction, through the medium of a helical spring clutch 37 riding with slight clamping action on a hub of the wheel 34, and attached at one end to a disc 38 fixed to the shaft 20. A similar arrangement is provided for the drums 7, 8, the corresponding helical spring clutch 48 being disposed, however so as to be inactive when the direction of rotation of the motor 4 is such as to cause clutch 37 to grip, and vice versa. In operation, both loads may be simultaneously lowered by manipulating both wheels 31 so as to free the pinions 19. If the motor 4 is turning in the direction which causes wheel 34 to grip its shaft 20, the drums 5, 6 may be either stopped or turned back to raise their load, by suitable adjustment of the corresponding wheel 31. Reversal of the motor 4 will allow similarly of the drums 7, 8 raising their load. In order to hold the loads when the motor 4 is inoperative, a helical spring clutch 41 is provided in each case between the disc 38 and the frame 9 thus holding the shaft 20 against reverse movement when the clutch is engaged by wheel 31 to arrest the pinion 19. In a modification the spring clutch 37 is replaced by a screw clutch, and the wheel 31 controls a multiplate clutch one part of which carries the centrifugal brake.