| 摘要 |
PURPOSE:To perform automatic speed changer in a bicycle by a method wherein the period outputted by an oscillator for one rotation of a bicycle wheel is counted and said count value and the count values being set for each chain gear are compared with each other. CONSTITUTION:A reflection plate 3 is attached to a measuring disc 2 in mesh with a wheel 1, and a reflection type photo-electric sensor 4 which detects said reflection plate 3 is fixed to the bicycle body. The period for one rotation of the measuring disc 2 is counted utilizing the stable frequency of the oscillator 5. Each count value corresponding to respective range of employing speed being set at each chain gear is memorized at a memory 7, said value being compared with the one obtained by the aforementioned count value, and to which chain gear the obtained count value belongs is determined. By said process, if the determination differs from the chain gear in present use, the chain gear is switched to the determination by controlling a motor 8 through the output of the calculator 6. |
