To provide a mechanical output without any electric signal and the like.

A rotational shaft 4 is energized to reversal direction by a spring 16 and speed at reversal rotating is adjusted by a speed governor wheel 20 when the rotational shaft 4 is normally turned. An output shaft 8 is normally turned by engaging a first cum part 10 with the rotational shaft 4 at normal rotation and it is in reversal turnable state by itself at reversal rotation. A contact mechanism 24 stops its reversal rotation by engaging with the first cum part 10 when the output shaft 8 is normally turned and turned at constant angle. When the rotational shaft 4 returns to its initial position, engagement of the contact mechanism 24 with the first cam part 10 is canceled. Whereby, the output shaft 8 is immediately reversed and returns to its initial position.