Door operator control mechanism and system

Claim 1

A DRIVE MECHANISM INCLUDING A REVERSIBLE MOTOR AND A SLIP CLUTCH HAVING A ROTATABLE INPUT ELEMENT DRIVEN BY SAID MOTOR AND A ROTATABLE OUTPUT ELEMENT CONNECTED TO DRIVE A LOAD, SAID CLUTCH SLIPPING AND SAID OUTPUT ELEMENT STALLING WHEN A PREDETERMINED LOAD IS APPLIED TO THE LATTER, CONTROL MEANS FOR SELECTIVELY ENERRGIZING SAID MOTOR TO ROTATE IN EITHER OF ITS DIRECTIONS OF ROTATION AND INCLUDING REVERSING MEANS FOR REVERSING SAID MOTOR AND CAUSING THHE LATTER TO OPERATE IN ONE DIRECTION AND CONDITIONED TO BE EFFECTIVE WHEN SAID MOTOR IS ENERGIZED TO OPERATE IN ITS OTHER DIRECTION COMPRISING FIRST MEANS RESPONSIVE TO THE ROTATION OF SAID OUTPUT ELEMENT AND OPERATED MOMENTARILY FROM A NORMAL CONDITION WHICH IT HAS WITH SAID OUTPUT ELEMENT AT REST OR ROTATION TO AN ACUTATED CONDITION AND RETURNED TO ITS NORMAL CONDITION WHEN SAID OUTPUT ELEMENTT CHANGES FROM A ROTATING CONDITION ABOVE A PREDETERMINED ANGULAR SPEED TO ONE BELOW THAT SPEED, SAID FIRST MEANS HAVING SAID ACTUATED CONDITION ONLY DURING THE MOMENTARY OPERATION THEREOF, AND MEANS RESPONSIVE TO THE MOMENTARY ACTUATION OF SAID FIRST MEANS FOR ENERGIZING SAID MOTOR TO OPERATE IN A REVERSE DIRECTIONNN TO SAID OTHER DIRECTION.