Actuator with self-protecting limiting mechanism

Claim 1

IN AN ELECTROMECHANICAL ACTUATOR HAVING AN OUTPUT SHAFT ROTATABLE IN OPPOSITE DIRECTIONS TO MOVE A DEVICE BETWEEN EXTENDED AND RETRACTED POSITIONS AND A REVERSIBLE MOTOR COUPLED TO SAID SHAFT, A LIMITING MECHANISM COMPRISING: AN EXTERNALLY THREADED AND ROTATABLY CAM SHAFT COUPLED TO SAID OUTPUT SHAFT; SWITCH MEANS ACTUATABLE FOR DE-ENERGIZING SAID MOTOR; A NUT MOUNTED ON SAID CAM SHAFT IN ENGAGEMENT WITH SAID THREADS, WHEREBY RELATIVE ROTATION BETWEEN SAID NUT AND SHAFT CAUSES SAID NUT TO MOVE AXIALLY OF SAID SHAFT; A BRAKE MOUNTED IN FACE-TO-FACE RELATIONSHIP WITH SAID NUT; MEANS ON SAID NUT URGING SAID BRKE INTI FRICTIONAL ENGAGEMENT WITH SAID NUT TO RESTRAIN RELATIVE ROTATION THEREOF; GUIDE MEANS PARALLEL TO AND OFFSET FROM SAID CAM SHAFT, SAID GUIDE MEANS BEING ENGAGED WITH SAID BRAKE TO PREVENT ROTATION, BUT TO PERMIT AXIAL MOVEMENT THEREOF RELATIVE TO SAID CAM SHAFT; AND MEANS ON AID BRAKE ENGAGING SAID SWITCH MEANS FOR ACTUATING THE SAME.