| 摘要 |
<p>PURPOSE:To prevent occurrence of malfunction by providing a slip gear connected to a drive-side gear through the intermediary of a slip mechanism and by transmitting from the slip gear a starting rotational force for a cam gear at a standby position. CONSTITUTION:In a cam gear 3, a second gear 7 engaging with a driveside gear 2 and also teeth-lacking parts 7a and 7b thereof are formed in the lower part of an outer peripheral surface, while a first gear 21 engaging with a slip gear 11 is formed in the upper part of the outer peripheral surface. A starting rotational force for a cam gear 3 at a standby position is given by the first gear 21 engaging with the slip gear 11. When a power source is turned OFF and the drive-side gear 2 stands still, accordingly, the starting rotational force is not given to the cam gear 3. Even when a lock lever 6 is made to rotate by vibration or the like and locking is removed, therefore, the gear 3 stands still as it is at the standby position and engagement of the gear 7 with the drive-side gear 2 does not occur. Thereby malfunction can be eliminated.</p> |
