| 摘要 |
PURPOSE:To automatically change over a transmission ratio in accordance with a load by switching over the combination of a plurality of driven pulleys and a belt based on the signals of a pressure sensor and a rotating position detecting sensor provided on the rotary shaft bearing portion of a driving pulley by means of a crank-pedal mechanism. CONSTITUTION:A pressure sensor 13 is provided on the bearing portion of the rotation driving shaft of a driving pulley by means of a crank-pedal mechanism while also providing the rotating position detecting sensor 14 thereof. Based on the detected values of the sensors, the average value cf the loads is obtained by an arithmetic circuit 21, and compared with a previously set value to automatically switch over the engagement of a plurality of driven pulleys and a belt in accordance with a load. It is also possible to carry out speed indication based on the detected value of the rotating position detecting sensor 14. Thereby, the optimum transmission ratio in accordance with a load can be automatically obtained. |
