GB391789A - Improvements in or relating to variable speed transmission mechanism - Google Patents

Abstract

391,789. Variable speed linkwork gearing ; links. OSBORNE, W., The Box, Bramhall Lane, Stockport. Sept. 3, 1931, No. 24748. [Classes 80 (ii) and 80 (iii).] Variable-speed gearing comprises transmission links or struts a<1>, a<2>, Fig. 1, connecting a driving member or members A<1>, A<2> to a driven member B<1>, the link being freely variable in length on the idle stroke but rigid in one direction on the power stroke. The members A<1>, A<2> are twin swash-plates carried on a driving-shaft A with equal and opposite inclinations which are varied in unison to vary the speed of a shaft B carrying the driven swash-plate Bl of fixed inclination. The links a<1>, a<2>, which both engage the plate B<1> and alternately engage the plates A<1>, A<2>, are adapted to reciprocate in apertures in a fixed frame D. In a development shown in Fig. 13, the links are struts numbered 1, 2 .. 9, 10. The struts 2, 8, 9 are rigid,. effecting power strokes to turn the plate B<1>, while the others are freely variable in length and idle. One form of link is shown compressed in Fig. 3 and extended in Fig. 4. There are feathered connections e, Fig. 3, which prevent four nuts El .. E4 from turning in the frame D. The nuts E<1>, E2 are right-handed, and the nuts E3, E4 left-handed, with threads of low pitch. The end nuts E<1>, E4 engage different singlescrewed sleeves F<1>, F<3>. The middle nuts E2, E<3> engage the same double-screwed sleeve F<2>. The sleeves F<1>, F<2>, F<3> are all feathered on a sleeve nut H connected to one end swivel link C. A screw J of steep pitch engaging the sleeve nut H is connected through a lost-motion spring box to the other end swivel link C<1>. The screws of low pitch jam to transmit thrust, or collapse, according as the spiral J is in a position to take the end thrust or is not in position. The spiral J is adjusted axially as required to make and break the link by turning a crown J<4> having a saw-tooth connection with a head J<1> on the spiral. This turning of the crown J<4> is effected by cam mechanism J<5>, J<6>, Fig. 1. The gearing is set for forward drive, neutral, and reverse by turning the cam J<6> relatively to the shaft B by the axial displacement of a control spiral N<1>. A modification is described in which links of this screw type are arranged radially round a driving variable-throw eccentric and serve to drive variably a star-wheel upon a driven eccentric. An hydraulic construction of link is shown in Fig. 7. Cylinders P<1>, p<2> are connected by a clip ring P so as to slide together. The cylinder P<2> carries one swivel end link C. A rod R<1> with two pistons R<2>, R<3> carries the other end link C<1>. The adjacent ends S<1>, S<2> of the cylinders are perforated, and the whole strut is rigid or collapsable according to how the cylinder P<1> is turned relatively to the other one. This relative turning is effected by a cam like the cam J<6>, Fig. 1, operating at O<4>, Fig. 7.