GB932155A - Improvements in or relating to drive transmissions - Google Patents

Abstract

932,155. Variable-speed gear. DOWTY ROTOL Ltd. Dec. 14, 1960 [Dec. 14, 1959], No. 42504/59. Class 80 (2). [Also in Group XXX] In a drive transmission a power drive may be established to an output member from a first input member through a clutch, or a manual drive from a second input member, the clutch being released upon the engagement of the manual operating member with the second input member. The invention is shown as applied to the drive of a winch worm 17 and wheel 15, the first input member being the stub shaft 36 of an hydraulic motor 20, and the second input member a splined sleeve 38 engageable by a handle 24, normally used for regulating the motor control valve, upon the removal of a cover plate 26. The drive from shaft 36 to worm 17 is transmitted through a dog clutch 34, 35, release of which is effected upon engagement of handle 24 with sleeve 38 by a spring plunger 65 in the handle (Fig. 4). With handle 24 in position a direct drive to worm 17 may be obtained, or a high ratio drive through a three-element epicyclic gear 41, 42, 43. As shown an engaged ratchet clutch 45, 46 associated with the epicyclic gear enables the latter to lock solid for direct drive in one direction, but operation of a trigger device 55 locks the gear annulus 43 and engages a second ratchet clutch 51, 52 to permit operation of planet pinions 42 and the transmission of a higher ratio to the worm 17. The handle may also be of a form to prevent operation of the ratchet gear, Fig. 3 (not shown), thus allowing hand drive in either direction.