摘要 |
A rotational-locking member such as an endless screw for actuating a sliding door by means of a nut is locked in position by rotational displacement of the nut and is unlocked by means of a device comprising a pulley coupled to the endless screw and rigidly fixed to a clutch-disk. A second clutch-disk slidably mounted on a square sleeve of a bevel-pinion can be rotated by means of a pair of bevel-pinions and a lever. A lug of the second disk cooperates with a helical groove of a stationary cam in order to subject the disk to a helical movement, the rotational motion component of which is imparted to the endless screw after engagement of the disks in order to unlock the screw. |