Automatic door operator control systems

Claim 1

A CONTROL SYSTEM FOR AN AUTOMATIC DOOR OPERATOR HAVING TWO POSITIONS 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, (C) SPRING MEANS HAVING AN INNER END AND AN OUTER END, THE INNER END OF SAID SPRING MEANS AND ONE END OF SAID CYLINDER BEING CONNECTED TO A FRAME, THE OUTER END OF SAID SPRING MEANS AND SAID PISTON BEING CONNECTED TO A LEVER PIVOTALLY CONNECTED TO SAID FRAME, SAID LEVER BEING PIVOTALLY CONNECTED TO SAID DOOR FOR OPERATING SAME, SAID SPRING MEANS PROVIDING FORCE FOR EXHAUSTING SAID PRESSURIZED FLUID FROM SAID CYLINDER WHEN SAID DOOR OPERATOR REACHES THE APPROXIMATE MIDPOINT OF ITS TRAVEL FROM SAID ONE OF ITS SAID POSITIONS TO THE OTHER OF SAID POSITIONS AND FOR CAUSING SAID OPERATOR TO COMPLETE ITS MOVEMENT TO SAID OUTER 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 AND AN EXHAUST IN COMMUNICATION WITH THE ATMOSPHERE, (F) VALVE MEANS LOCATED WITHIN SAID CONTROL VALVE, (G) SAID VALVE MEANS HAVING A FIRST POSITION WHEREIN SAID VALVE MEANS PERMITS THE PASSAGE OF FLUID FROM SAID FLUID SOURCE TO SAID CYLINDER AND PISTON AND PREVENTS THE PASAGE 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) ACTUATING MEANS ASSOCIATED WITH SAID CONTROL VALVE TO CAUSE MOVEMENT OF SAID VALVE MEANS BACK AND FORTH BETWEEN SAID FIRST AND SECOND POSITIONS, (I) SAID ACTUATING MEANS COMPRISING A TWO STAGE SOLENOID HAVING A FIRST COIL WHICH CAUSES SAID VALVE MEANS TO MOVE TO SAID FIRST POSITION WHEN AN ELECTRIC CURRENT IS PASSED THERETHROUGH, AND HAVING A SECOND COIL WHICH CAUSES SAID VALVE MEANS TO MOVE TO SAID SECND POSITION WHEN AN ELECTRIC CURRENT IS PASSED THERETHROUGH, (J) A NORMALLY OPEN ENERGIZING SWITCH IN SERIES WITH SAID FIRST COIL WHICH WHEN CLOSED WILL PERMIT AN ELECTRIC CURRENT TO PASS THROUGH SAID FIRST COIL, (K) AT LEAST ONE NORMALLY OPEN DE-ENERGIZING SWITCH IN SERIES WITH SAID SECOND COIL WHICH WHEN CLOSED WILL PERMIT AN ELECTRIC CURRENT TO PASS THROUGH SAID SECOND COIL, AND (L) MEANS ASSOCIATED WITH SAID DOOR OPERATOR FOR CLOSING SAID DE-ENERGIZING SWITCH WHEN SAID DOOR OPERATOR REACHES THE APPROXIMATE MIDPOINT OF ITS TRAVEL FROM ONE OF ITS POSITIONS TO THE OTHER OF SAID POSITIONS.