GB189800726A - An Improved Duplex Driving Gear for Bicycles and other Cycles, and for other purposes. - Google Patents

Abstract

726. Thompson, W. J. Jan. 11. Toothed gearing for bicycles and other cycles and for other purposes whereby a two-speed gearing is obtained. The disc B secured at A<1>, A<2> to the crank A carries pins B' for the toothed pinions C, each of which gears with the toothed wheel D running on ball bearings D<1> and also with the internal teeth of the chain-wheel E. A locking- plate F has slot guides F<1> on pins B<2> on the disc B, and bears against a spring F<4> adapted to maintain the sector F<3> attached to the plate in gear with the wheel D, and the key piece F<5> in engagement with the slot d<2>, and so cause the motion of the crank A to be transmitted to the chain-wheel rim without multiplication. A locking-pin G is carried by bands or clips G<2>, and has a spring G<1> suitably controlled, adapted to press it against the driving-gear. When the control is released, the pin G is forced against the dust case H, which has an opening through which protrudes a flange F' of the locking-plate F. The pin G catches on the inside of the piece F', and forces it outwards and thus moves the plate into the position shown by dotted lines in Fig. 2. This releases the wheel D from the sector F<3> and the key F<5>, and as the wheel D revolves the pin G engages with the socket and thus prevents further revolution of the wheel D. By this means the revolutions of the crank are multiplied upon transmission to the chain-wheel E. To change from high to low gear the pin G is withdrawn. The operating-connections consist of a draw piece J<1>, bell-crank levers J<2>, J<4>, chains, cords, or rods J<3>, J<5>, and a hand-lever J.