摘要 |
A multiple speed shaft drive for a bicycle, including: a forward disk having a plurality of concentrically disposed ring gears, wherein the forward disk is connected with the pedal crank of the bicycle; a rearward disk having a plurality of concentrically disposed ring gears, wherein the rearward disk is connected to the rear wheel hub; a forward drive shaft; a rearward drive shaft; a free wheel mechanism connecting the forward drive shaft to the rearward drive shaft; a forward pinion gear slidably mounted to the forward drive shaft; a rearward pinion gear slidably mounted to the rearward drive shaft; a forward gear shift mechanism for moving the forward pinion gear into gearing engagement with a selected ring gear of the forward disk; a rearward gear shift mechanism for moving the rearward pinion gear into gearing engagement with a selected ring gear of the rearward disk; and a clutch mechanism which automatically disengages the rearward hub from gearing engagement with the rearward pinion gear whenever a gear shift is made with a shift control operated by the cyclist.
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