GB739713A - Improvements in or relating to infinitely variable speed gear mechanisms - Google Patents

Abstract

739,713. Converting rotary into reciprocating motion ; variable speed gearing. TOOTAL BROADHURST LEE CO., Ltd. June 18, 1953 [June 18, 1952], No. 15301/52. Classes 80 (1) and 80 (2). In a hypocycloidal gear mechanism for converting a rotary motion into a reciprocating motion, a crank-pin 3b on a planet pinion 2b, which rolls around an internal gear 1b of twice its diameter and is carried on a driving member 9, performs a reciprocating movement in a guide slot 14 of a member 15. The internal gear 1b may be adjusted circumferentially by means of a worm 11 and teeth 12 so as to alter the line of action of the crankpin 3b and thereby impart an oscillating movement to the member 15. This oscillating movement of member 15 may be utilized to drive a shaft 26 at varying speeds by means of arms 16, 17, gear segments 20, 21 and unidirectional driving devices 22, 23. Alternatively, the member 15 may be reciprocated along guides at right angles to the slot 14 which movement may be transmitted to unidirectional driving devices through cables around pulleys. To give a more uniform drive, a second crankpin spaced 90 degrees out of phase to the crankpin 3b may drive another member 15 with a slot 14 at 90 degrees to that of the first member 15. The slotted and guided member 15 may also be used to drive a pump plunger, the stroke of which may be varied by adjusting the internal gear circumferentially. The pump plunger'may also be coupled to the crank-pin by a connecting rod instead of the slotted member 15. A modified gear arrangement is also described in which the planet pinion carrying the reciprocating crank-pin gears with an idler planet which rolls around an external gear which is adjustable in a similar manner to the internal gear to vary the line of reciprocation of the crank-pin.