GB189718034A - Improvements in or relating to Driving-gear for Cycles and other Vehicles. - Google Patents

Abstract

18,034. Ehrhardt, H. July 31. Driving-mechanism, variable-speed. The Figures show the application of the invention to a bicycle. On the inner side of one of the pedal cranks d are fixed two spur-wheels or concentric rings of teeth e, e<1> as shown. A wheel c, mounted on a hexagonal part of a tube a carried in ball bearings by the cycle frame, can slide into engagement with either set of teeth e or e<1>. A spring stop f fitting into holes in the tube a secures it in either position. A gearwheel b, secured to the rear end of the tube a, engages holes formed in a disc g fixed to the driving-wheel hub and drives the cycle. In order to diminish the travel of the wheel c, a wide wheel, or two wheels secured together, may be used. In a modification, conical teeth secured to the crank engage either of two rows of teeth formed on a drum-wheel which replaces the wheel c. Figs. 9 and 11 show another modification. Two wheels p and q secured to a tube 0 engage holes formed in discs l, l<1> as shown in Fig. 9. The tube 0 is mounted on a rod m, having eccentric pins n, n<1> pivoted in the frame as shown in Fig. 11. A cog-wheel r on the pin n engages a worm S. On turning the worm by means of the rod S' carried up to the top bar, the rod m moves into the position shown in Fig. 11, and permits the tube 0 to slide along it until the wheels p, q are in a position to engage the other series of holes, when the rod m is returned to its original position. The pin n may be extended rearwards and operated by a hand-wheel fixed on it.