GB1218104A - Improvements relating to winches and load cable means associated therewith - Google Patents

Abstract

1,218,104. Winches for cranes. J. S. THOMSON. 17 April, 1969 [23 April, 1968], No. 19001/68. Heading B8B. A winch comprises two winding drums 1, 2 each adapted to wind an opposite end of a single load cable of a crane, the drums selectively being either rotatable in unison or only one 1 being rotatable whilst the other drum 2 is held at rest. The drum 1 is fixed to a drive shaft 3 and the drum 2 is freely rotatable on the shaft 3, a dog clutch member 8 rotatably keyed to the shaft 3 being manually slidable along the shaft into and out of driving engagement with teeth 10 on the drum 2. The member 8 includes a groove 15 engageable with a roller 14 mounted on a clutch operating handle 12 pivoted to the winch frame at 13, the remote end of the handle operating a sliding spray 18. The latter is supported in the winch frame 6 and slides into engagement with a pocket 23 in the drum 2 to lock the same after the clutch has been disengaged, the spray automatically releasing the drum prior to reengagement of the clutch. A manually operated hand brake 21 for the drum 2 assists the clutching operation. In the embodiment of Fig. 2 (not shown), the winch is associated with a ship's derrick crane, the two reaches of load cable extending from the winch, over idler pulleys at the end of a slewing and luffing jib and down to a single pulley supporting a load hook, the latter being liftable with different purchase, by operation of one or both winch drums. The embodiment of Fig. 3 (not shown) is similar to that of Fig. 2, but the two reaches of load cable each pass over a pulley on the load hook and up to a common pulley suspended from the end of the jib whereby a greater purchase for load lifting is available.