GB946682A - Continuously variable change speed gear - Google Patents

Abstract

946,682. Variable-speed ratchet gear. GADELIUS & CO. A.B. April 7, 1960, No. 12409/60. Headings F2D and F2Q. A continuously-variable friction-ratchet change-speed gear comprises friction pawls 10 guided in a circular track 12 in a driven disc 2 and having studs 11 slidably engaged in radial grooves 16 in a driving disc 1. The driven disc 2 is mounted in a carrier pivotable about an output shaft 7, to which the disc 2 is geared, so that the eccentricity of disc 2 may be adjusted relative to the disc 1 to vary the gear ratio. The friction pawls 10 are rectangular in section with diagonally opposite edges 23, 24 rounded and with flat faces 21, 22 slidable over the side walls 13, 14 of the circular track 12. When the stud 11 is subjected to a force in the direction B, the pawl is tilted anticlockwise and the rounded edges are wedged against the side walls. The flat faces 21, 22 prevent wedging of the pawls when the stud is subjected to a force in the opposite direction. The pawls thus successively grip the track in the zone of the track the greatest distance from the axis of the disc 1 and release the track away from this zone as they move inwards along the radial slots 16 and are subjected to a clockwise moment. The slots 16 are provided in linings in the disc 1 which are mounted for angular movement about radial axes so as to allow the tilting movements of the pawls. Each lining is spring biased to a position close to the locking position for its pawl so that the tilting movement is as small as possible.