GB200337A - A new or improved variable speed gear - Google Patents

Abstract

200,337. Turnbull, D., and Withers, A. T. June 20, 1922. Variable-speed gearing comprises pairs of racks 20, 20<a> reciprocated with variable amplitude and driving through one - way devices comprising worm gearing. Thus rack 20 oscillates a pinion 22 to which a wormwheel 24 and an internal gear 26 are secured. A worm 30 is carried by a revoluble frame 40 which also carries a toothed train adapted to drive the worm from the gear 26. When the worm-wheel 24 moves in one direction, it binds against and drives the worm solidly and so drives the frame 40. Movement in the opposite direction causes the gear 26 to drive the worm, which slips over the worm-wheel, which is thus allowed to return idly. The arrangement is made doubleacting by the other rack 20<a> and other trains 25, 31, 27, &c., the same frame 40 being driven. The frame 40 is secured at 46 to a driven or intermediate shaft 10. The driving-shaft 12 carries a casing 13 which carries in guides 15 a reciprocal slide 16 to which the racks 20, 20<a> are secured. The slide 16 engages also blocks 68 upon an eccentric sheave 43 which turns within a non-rotary bearing 44 the eccentricity of which is adjusted to vary the speed transmitted. The double-acting worm one-way device is duplicated on the right of the eccentric 43, the casing 13 there shown turning solid with the first casing 13, and the two sets of gearing are co-ordinated by an epicyclic train 50, 53, 51 to drive a disc 56 with constant speed. This through a train 57, 58, 60, 65 drives a tail shaft 67.