| 摘要 |
A driving coupling includes two pawls which are supported pivotally on an eccentric ring and which in a patternlike manner engage a longitudinal groove in the drive shaft. Each of two plates of a toggle-lever joint engages an arm extension of a respective pawl, the swivel axle of the toggle-lever joint being guided in a control groove of a swinging switching arm. When the pawls are engaged with a drive shaft groove, the toggle-lever joint is in an extended position which locks the pawls in position. For unlocking the pawls, the switching arm moves the toggle-lever joint into a catch opening between two guide rails. The pawls swing out and the drive shaft rotates without carrying along the pawls and the eccentric ring. |
