GB1400393A - Automatic change for three speed reduction gears - Google Patents

Abstract

1400393 Change-speed gear LEWMAR MARINE Ltd and D J FAWCETT 3 July 1972 [2 July 1971] 31197/71 Heading F2D A three-speed drive, from a handle 3 to a drum 1 of a winch, provides two forward reduction ratios by forward and reverse rotation of the handle, and a faster, but still reduced, forward ratio by rotating the handle forwards after engaging a toothed clutch 13, 14 by depressing a central plunger 16. The highest output speed, with clutch 13, 14 engaged, passes from the forwardly rotated handle 3 through a tubular shaft 2 to which the handle is secured; clutch member 5 slidably keyed at 11 to the shaft 2; clutch teeth 13, 14; freely mounted wheel 4; countershaft stepped pair 7, 8, and a second countershaft pair 9, 10, Fig. 4, to an internal ring gear 6 fast in the drum 1. For second ratio the handle 3 is rotated reversely, which causes disengagement of the clutch 13, 14 by axial thrust produced by engagement of inclined trailing faces 17, 18 of the clutch teeth 13, 14. Drive now passes from the handle to the drum in the same direction as before through the shaft 2, one-way clutch 21, wheel 20, countershaft pair 9, 10 and forwardly rotated ring gear 6. For third ratio (lowest output speed, still forward), the handle 3 is again rotated forwards, the clutch 13, 14 being held disengaged by a ball detent 15. The one-way clutch 21 now overruns and drive passes from the shaft 2 through wheels 24, 22, a second one-way clutch 23, wheel 8, and second countershaft pair 9, 10 to the ring gear 6. Included between the wheels 9, 10 of the second countershaft pair is a forward driving one-way clutch 25, Fig. 4, which permits the which drum to overrun in any ratio and hence ensures that the disconnectible high ratio clutch 13, 14 can be disengaged only by reversing the handle rotation and not by overrun of the drum.