Vacuum die casting apparatus

Claim 1

IN A DIE CASTING APPARATUS INCLUDING AN ATMOSPHERICALLY VENTED CAVITIED DIE, A HORIZONTALLY DISPOSED CYLINDRICAL COLD CHAMBER IN OPEN COMMUNICATION THEREWITH, A POWER-OPERATED INJECTING PLUNGER RECIPROCAL WITHIN SAID COLD CHAMBER TO CHARGE FLOWABLE LIQUID CASTING MATERIAL DELIVERED THERETO DIRECTLY INTO SAID CAVITIED DIE, AND A CHARGING APERTURE THROUGH AN UPPER WALL SURFACE OF THE COLD CHAMBER ADJACENT AND IN ADVANCE OF THE INJECTION PLUNGER IN ITS RETRACTED POSITION WITHIN THE COLD CHAMBER REMOTE TO SAID CAVITIED DIE, THE IMPROVEMENT COMPRISING: (A) A HOUSING CARRIED BY SAID COLD CHAMBER PROVIDING AN UPWARDLY AND OUTWARDLY DIRECTED SEALED CHAMBER IN OPEN COMMUNICATION THROUGH SAID CHARGING APERTURE WITH THE COLD CHAMBER AND VENTED CAVITIED DIE, (B) AN IMPERFORATE WALL OPEN ENDED FLOWABLE LIQUID CASTING MATERIAL DELIVERY CONDUIT EXTENDING AXIALLY COEXTENSIVELY DOWNWARDLY THROUGH AND FROM ABOVE AN UPPER WALL OF SAID HOUSING AND HAVING ITS OPEN DISCHARGE END TERMINATING THEREWITHIN ISOLATED FROM INTERIOR WALLS OF THE COLD CHAMBER AND IN SUBSTANTIALLY AXIALLY TANGENTIAL DISPOSITION IN RESPECT TO AN INTERIOR WALL OF SAID COLD CHAMBER CLOSELY ADJACENT SAID CHARGING APERTURE, (C) SAID CONDUIT BEING CURVILINEARLY DOWNWARDLY AXIALLY CONTIGUOUSLY DIRECTED TO LOCATE ITS OPPOSITE OPEN END BELOW AN ATMOSPHERICALLY EXPOSED SURFACE OF A SOURCE OF FLOWABLE CASTING MATERIAL LOCATED BELOW THE COLD CHAMBER, (D) MEANS FOR INDUCING A LOW LEVEL VACUUM WITHIN SAID COLD CHAMBER IN ADVANCE OF THE INJECTING PLUNGER IN ITS RETRACTED POSITION REMOTE TO SAID CAVITIED DIE, (E) ELECTRICALLY ENERGIZABLE OPERATING CIRCUITRY INCORPORATING A PAIR OF ELECTRICALLY RESPONSIVELY TIMED VALVES SEQUENTIALLY CONTROLLING INITIATION AND DURATION OF THE INDUCED VACUUM AND ACTIVATION OF A SOURCE OF POWER INITIATING THE INJECTION STROKE OF THE INJECTING PLUNGER WITHIN THE COLD CHAMBER IN CONSECUTIVELY TIME-DELAYED SEQUENCE, (F) ENERGIZATION OF ONE OF SAID VALVES BEING TIMED TO EXPIRE AND CUT-OFF THE INDUCED VACUUM AND A METERED QUANTITY OF FLOWABLE LIQUID CASTING MATERIAL RESPONDING TO THE INDUCED VACUUM DELIVERED TO SAID COLD CHAMBER THROUGH SAID FLOWABLE LIQUID CASTING MATERIAL DELIVERY CONDUIT, AND (G) ENERGIZATION OF THE OTHER OF SAID VALVES FOR INITIATING THE INJECTION STROKE OF SAID INJECTION PLUNGER BEING SET TO INITIATE THE INJECTING PLUNGER CHARGING STROKE IN SELECTIVE TIMED DELAY FOLLOWING EXPIRATION OF THE INDUCED VACUUM CONTROLLING VALVE, WHEREBY FLOWABLE LIQUID CASTING MATERIAL WITHIN THE DELIVERY CONDUIT IS DIRECTIONALLY OPPOSITELY DRAINED INTO THE COLD CHAMBER AND SOURCE OF FLOWABLE LIQUID CASTING MATERIAL FROM OPPOSITE OPEN ENDS OF THE DELIVERY CONDUIT BEFORE INITIATION OF THE CHARGING OF THE INJECTING PLUNGER.