Method of, and apparatus for, die casting metals

Claim 1

APPARATUS FOR DIE CASTING METAL WHICH COMPRISES: A STATIONARY DIE PLATE AND A MOVABLE DIE PLATE WHICH WHEN THEIR RELATIVELY INNER FACES ARE CLOSED TOGETHER DEFINE A DIE CAVITY, THE STATIONARY DIE PLATE HAVING AN OPENING EXTENDING TRANSVERSELY THROUGH IT DIRECTLY BELOW THE DIE CAVITY, AND THE MOVABLE DIE PLATE HAVING A RECESS IN ITS RELATIVELY INNER FACE EXTENDING IN CONTINUATION OF THE OPENING IN THE STATIONARY DIE PLATE, A SLEEVE FIXEDLY DISPOSED IN THE OPENING IN THE STATIONARY DIE PLATE AND HAVING A CLOSED FORWARD END PORTION PROJECTING BEYOND THE RELATIVELY INNER FACE OF THE STATIONARY DIE PLATE AND ADAPTED TO MOVE INTO THE SAID RECESS IN THE CORRESPONDING INNER FACE OF THE MOVABLE DIE PLATE WHEN THE DIE PLATES ARE CLOSED TOGETHER, A SHORT-LENGTH NIPPLE AFFIXED TO AND PROJECTING RADIALLY FROM SAID FORWARD END PORTION OF SAID SLEEVE TO THE DIE CAVITY AND COMMUNICATING DIRECTLY BETWEEN THE SLEEVE AND THE DIE CAVITY, THE AXIS OF THE NIPPLE BEING ALIGNED WITH THE LINE OF PARTING BETWEEN THE DIE PLATES AND THE INNER FACES OF SAID DIE PLATES BEING COMPLEMENTALLY RECESSED TO PROVIDE A FULL TUBULAR SEAT FOR SAID NIPPLE, MEANS EXTENDING THE FULL LENGTH OF SAID SLEEVE FOR MAINTAINING THE SLEEVE AND NIPPLE AT A TEMPREATURE ABOVE THE MELTING POINT OF THE CASTING MATERIAL, A RESEVIOR FOR METAL CASTING MATERIAL DISPOSED BELOW SAID SLEEVE, AND MEANS FOR INTERMITTENLY RAISING A CHARGE OF CASTING MATERIAL FROM THE RESEVIOR TO THE DIE CAVITY INCLUDING A CONDUIT COMMUNICATING BETWEEN THE RESIVIOR AND THE REARWARD END PORTION OF THE SLEEVE AND A CHARGING PISTON RECIPROCABLE WITHIN THE SLEEVE TO FORCE A CHARGE OF CASTING MATERIAL FROM SLEEVE THROUGH SAID NIPPLE TO FILL THE CAVITY, THE CONDUIT COMUNICATING TO THE SLEEVE AT A POINT ALONG THE LENGTH THEREOF WHICH IS SO LOCATED THAT WHEN THE PLUNGER IS AT THE REAR END OF ITS STROKE THE CONDUIT CONNECTION TO THE RESEVIOR IS UNCOVERED, THUS ALLOWING MOLTEN METAL IN THE HEATED NIPPLE AND SLEEVE TO RETURN TO THE RESERVIOR BY GRAVITY AFTER EACH RECIPROCATION OF THE PLUNGER.