GB482361A - Improvements in change-speed devices - Google Patents

Abstract

482,361. Variable - speed gearing. LAILLE, R., and ROBERT, G. June 25, 1936, No. 17698. Void. Convention date, July 1, 1935. [Class 80 (ii)] A variable-speed drive from a shaft A to a shaft R is effected by ratchet devices between these shafts co-operating with an eccentrically displaceable drum D. These ratchet devices comprise segments B guided in circular grooves in the drum D and slidable in radial slots in disc members A<11> on the shafts A and R which co-operate with rocking pawls C<1> on the drum D. When the drum is concentric a direct drive takes place but on eccentric displacement it is driven from the shaft A at a higher speed and in turn drives the shaft R at a still higher speed. Friction or other one-way driving devices may be employed in place of the ratchet segments B. In the arrangement in Figs. 9-12 drums D<1> are secured to the driving and driven shafts and an intermediate shaft with slotted discs A<1> carrying segmental members B is eccentrically adjustable to vary the speed ratio. The segmental members B each carry a nest of small steel blades U which for a period of each revolution determined by a cam surface R<1> on the casing acting on push-pieces P, is pressed into the form of teeth at its sides, which teeth engage in teeth P<11> on the side plates of the drum D<1>. Thus successive segments B effect a positive drive connection between the drum D<1> and the corresponding disc A<1> as they come adjacent the cam surface R<1>, which arrangement allows both a speed reduction and a speed multiplication to be obtained by the same mechanism. These teeth may be formed however so as to drive in one direction only. In a modification, a wider speed variation is obtained by arranging two of these mechanisms in series.