摘要 |
An actuator has an output ram driven to extend and retract by a rotating lead screw. The lead screw is coupled with a rotating input shaft via a lost-motion drive sleeve connected with the input shaft by cooperating threads so that rotation of the drive shaft causes both axial and rotational movement of the drive sleeve. The ram is locked in its retracted position by several radially-extending locking keys, one end of which engage an extension sleeve fixed with the ram and the other end of which are engaged by a lock sleeve. Rotation of the input shaft causes the drive sleeve to move axially and engage the lock sleeve, thereby pulling it to one side and allowing the locking keys to move radially out and disengage the extension sleeve to allow it to extend. |