| 摘要 |
1,176,290. Winch drives. UNITED AIRCRAFT CORP. 18 Dec., 1968 [11 Jan., 1968], No. 60065/68. Heading B8B. A cargo hoist system for a helicopter comprises a hoist drive shaft 54 driven from a main rotor drive shaft 10 during cargo lifting, through a first one-way clutch 38, the rotor shaft 10 being driven by the hoist drive shaft 54 through a second one-way clutch 78, to retard the free fall of cargo being lowered by the shaft 54. For cargo lifting, a shaft 32 driven through gearing 12, 34 from the shaft 10, drives a gear 44 on the engaged clutch 38, which is of the ball and cam type. Gear 44 drives shaft 54 through gear 50, shaft 52, gears 59, 64 and clutch B, shaft 52 being coupled to a gear 36 on the shaft 32 through a second path comprising the second one-way clutch 78 having a gear 76. The clutch 78, also of the cam and ball type, overruns during cargo raising since the gear ratios 44, 50 and 76, 36 are arranged such that the casing of clutch 78 rotates faster than the cam thereof on the shaft 52, whereupon the ball does not lock and cam and casing. For cargo lowering, the shaft 52 is driven in the same direction as for raising, by the shaft 54 through a clutch A and as the rotational speed of the shaft 52 exceeds that of the clutch casing 78 being driven by the rotor shaft 10, the clutch 78 engages and acts to retard the lowering velocity of the cargo. During this operation the clutch 38 overruns due to the aforesaid gear ratios. The hoist may be operated while the helicopter is on the ground, by an auxiliary power unit 72 through a clutch 74, the one-way clutch 78 having been locked into a free wheeling mode by lever 88, whereupon one way clutch 38 will overrun. |
