Device for changing the gear ratio of a variable speed gear mounted to a bicycle

摘要

Discloses an electromechanical device for changing the gear ratio of a variable speed gear mounted to the hub of the rear wheel of a bicycle. The device consists of a changeover switch section to be mounted to the steering handle of the bicycle and an essential section to be coupled with the variable speed gear so as to operate the gear, said essential section includes a motor, gear means to be operated by said motor, and an electric circuit for connecting said motor to a power source. The electric circuit controls the motor according to the operation of the change-over switch and also controls the operation of the variable speed gear so that the gear ratio may be changed.