GB430881A - Change speed - Google Patents

Abstract

430,881. Variable speed gearing. BAUMGARTNER, E., 6, Kloosweg, Bienne, Berne, Switzerland. Nov. 19, 1934, No. 33268. [Class 80 (ii)] In two-speed constant-mesh countershaft gearing for cycles, gear is changed by momentarily back-pedalling, which action tilts a lever 25, to allow either of two radially-guided spring- pressed pawls 12, 13 to engage ratchet-teeth inside freely-mounted wheels 9, 10, to clutch them unidirectionally to the driving pedal-shaft 1. The wheel 10 carries a chain-sprocket R which drives the cycle, and the wheels 9, 10 mesh constantly with wheels 7, 8 fixed on the counter shaft 5. The pawl-controlling lever 25 is tilted by means of a slide 17, carried in a transverse slot in the pedal shaft 1, either end of the slide striking a fixed stop 21 which yields against a spring 22 in the forward direction. On back-pedalling, the slide strikes the bevelled face of the stop 21 and is thereby moved transversely in either direction to change the speed. The slide 17 is located in gear positions by a spring-detent 29. The stop 21 may be mounted on the countershaft 5 as shown, or on a separate shaft and may be moved out of action by a manual push-button. An additional shock-absorbing spring 41 may be provided to oppose the spring 22 and give the stop 21 an initial lift. Other shapes of spring are also shown. The eccentric mounting of the pedal shaft may be employed as a chain-adjuster, and the cycle-wheel may have two sprockets to double the available ratios.