Apparatus for casting that automatically controls the correlation between time and air-pressure

Claim 1

IN AN APPARATUS FOR CONTROLLING A CASTING PROCESS IN WHICH A MOLEN M ETAL BODY IS RAISED FROM A CONTAINER INTO A MOLD BY APPLICATION OF PRESSURIZED MEDIUM TO THE SURFACE OF THE MOLTEN IN THE CONTAINER AND BY THE APPLICATION OF SUCTION TO THE MOLD, A FIRST PNEUMATIC CIRCUIT INCLUDING VACUUM PUMP MEANS FOR APPLYING SUCTION TO SAID MOLD, A SECOND PNEUMATIC CIRCUIT FOR APPLYING PRESSURE TO SAID CONTAINER OVER SAID MOLTEN METAL, PROGRAMMING MEANS INCLUDING A TIME-PRESSURE CURVE FOLLWOING MEANS ADAPTED TO TRACE A PREDETERMINED TIME-PRESSURE CURVE, POTENTIOMETER MEANS CONNECTED TO RESPOND TO SAID TIME-PRESSURE CURVE FOLLOWING MEANS FOR DEVELOPING AN OUTPUT SIGNAL IN PROPORTION TO SID CURVE, FIRST VALVE MEANS DISPOSED IN SAID FIRST PNEUMATIC CIRCUIT BETWEEN SAID VACUUM PUMP MEANS AND SAID MOLD AND RESPONSIVE TO SAID OUTPUT SIGNAL FOR OPENING SAID FIRST PENUMATIC CIRCUIT IN RESPONSE THERETO AND PERMITTING SAID PRESSURIZED MEDIUM TO ENTER SAID CONTAINER, SECOND VALVE MEANS DISPOSED IN SAID SECOND PNEUMATIC CIRCUIT AND RESPONSIVE TO SAID OUTPUT SIGNAL FOR OPENING SAID SCOND PNEUMATIC CIRCUIT IN RESPONSE THERETO AND PERMITTING SAID PRESSURIZED MEDIUM TO ENTER SAID CONTAINER, THIRD PRESSURE RESPONSIVE VALVE MEANS DISPOSED IN SAID FIRST PNEUMATIC CIRCUIT BETWEEN SAID FIRST VALVE MEANS AND SAID MOLD, SAID THIRD VALVE MEANS HAVING A DIAPHRAGM CHAMBER INCLUDING A CONTROL DIAPHRAGM CONNECTED TO RESPOND TO A DIFFERENCE IN THE PRESSURES EXISTING AT SAID VACUUM PUMP MEANS AND AT SAID MOLD, TIMING MEANS DISPOSED IN A BRANCH CIRCUIT CONNECTING SAID DIAPHRAGM CHAMBER AT ONE SIDE OF SAID DIAPHRAGM TO SAID PNEUMATIC CIRCUIT AT THE PRESSURE BRANCH THEREOF NEARER TO SAID MOLD, SAID TIMING MEANS CONTROLLING THE PERIOD DURING WHICH SAID THIRD VALVE MEANS IS OPEN, PRESSURE RESPONSIVE MEANS FOR SENSING A PREDETEMINED PRESSURE IN SAID CONTAINER AND ACTUATING SAID TIMER MEANS, AND FURTHER VALVE MEANS DISPOSED IN SAID SECOND PNEUMATIC CIRCUIT FOR RELEASING PRESSURE FROM SAID CONTAINER IN RESPONSE TO LAPSE OF A PREDETERMINED PERIOD MEASURED BY SAID TIMING MEANS.