| 摘要 |
This control device for electric motor-reduction units comprises two cams rotating at different speeds about a common shaft, each cam having only one notch formed in its outer periphery, the cam notches being adapted to cooperate with catch-forming portions of a rocker controlling the motor switch. The first cam is rigid and coaxial with a toothed wheel meshing with a driving toothed pinion pivoted on a shaft parallel to the cam shaft, and comprises two drive teeth adapted, during each revolution, to mesh with a reversing pinion pivoted to the driving pinion shaft and rigid with another pinion meshing with a second toothed wheel rigid with the second cam. The teeth number of this last-mentioned pinion and the teeth number of the second toothed wheel are so selected that the notches cooperate again and simultaneously with the catch forming portions of the rocker only when the second cam moving step by step has accomplished n full revolutions, with n being at least equal to two, during which it has accomplished N full steps, N being not a multiple of n, while the first cam accomplished N full revolutions. This device is intended notably for controlling motor-reduction units driving rolling shutters, roller-blinds or the like. |
