Automatic door operator control systems

Claim 1

A CONTROL SYSTEM FOR AN AUTOMATIC DOOR OPERATOR HAVING TWO PORTIONS CORRESPONDING TO OPEN AND CLOSED POSITIONS, RESPECTIVELY, FOR AN ASSOCIATED DOOR OPERATED THEREBY, SAID CONTROL SYSTEM COMPRISING: (A) A FLUID-OPERATED PISTON LOCATED IN RECIPROCABLE RELATION WITHIN A CYLINDER, (B) SAID PISTON AND SAID CYLINDER BEING CONNECTED TO SAID DOOR OPERATOR SUCH THAT WHEN PRESSURIZED FLUID IS SUPPLIED TO SAID CYLINDER SAID PISTON AND SAID CYLINDER WILL INITIATE MOVEMENT OF SAID DOOR OPERATOR FROM ONE OF ITS SAID POSITIONS TO THE OTHER SAID POSITION, AND SUCH THAT SAID PISTON WILL EXHAUST SAID PRESSURIZED FLUID FROM SAID CYLINDER DURING COMPLETION OF THE MOVEMENT OF SAID OPERATOR TO SAID OTHER POSITION, (C) SPRING MEANS CONNECTED TO SAID DOOR OPERATOR TO CAUSE SAID OPERATOR TO COMPLETE ITS MOVEMENT TO SAID OTHER POSITION, (D) A SOURCE OF FLUID UNDER PRESSURE, (E) A CONTROL VALVE HAVING AN INLET IN COMMUNICATION WITH SAID FLUID SOURCE, AN OUTLET IN COMMUNICATION WITH SAID CYLINDER AND SAID PISTON, AN EXHAUST IN COMMUNICATION WITH THE ATMOSPHERE AND A PILOT CHAMBER HAVING A PILOT INLET, (F) VALVE MEANS LOCATED WITHIN SAID CONTROL VALVE, (G) SAID VALVE MEANS HAVING A FIRST POSITION WHEREIN SAID VALVE MEANS PERMITS TO PASSAGE OF FLUID FROM SAID FLUID SOURCE TO SAID CYLINDER AND PISTON AND PREVENTS THE PASSAGE OF FLUID TO SAID EXHAUST, AND HAVING A SECOND POSITION WHEREIN SAID VALVE MEANS PREVENTS THE PASSAGE OF FLUID FROM SAID FLUID SOURCE TO SAID CYLINDER AND PISTON AND PERMITS THE FLOW OF FLUID FROM SAID CYLINDER TO SAID EXHAUST, (H) A NORMALLY CLOSED ENERGIZING VALVE IN COMMUNICATION WITH SAID SOURCE OF FLUID UNDER PRESSURE AND