Method of and apparatus for making plastic articles

Claim 2

A PLASTIC ACCUMULATING AND DISCHARGING APPARATUS FOR A MOLDING MACHINE AND INCLUDING A PLASTICIZER FOR SUPPLYING PLASTICIZED MATERIAL AT A PLASTICIZER OUTPUT PRESSURE AND A DISPENSING ORIFICE, COMPRISING AN ACCUMULATOR BLOCK HAVING AN INTERIOR CAVITY PROVIDED WITH AN INLET OPENING FOR RECEIVING MATERIAL FROM THE PLASTICIZER AND AN OUTLET OPENING THROUGH WHICH MATERIAL IS SUPPLIED TO SAID ORIFICE, AN ACCUMULATOR PISTON PROJECTING FREELY INTO SAID CAVITY AND MOVABLE RELATIVE THERETO TO DEFINE AN ACCUMULATOR SPACE OF VARYING VOLUME, MEANS CONSTANTLY URGING SAID PISTON INTO SAID CHAMBER AND PROVIDING A LESSER BACK PRESSURE AGAINST WHICH THE ACCUMULATOR SPACE IS FILLED FROM THE PLASTICIZER AND AT THE PLASTICIZER OUTPUT PRESSURE, A SINGLE MOVABLE VALVE MEANS COMPRISING AN ELEMENT HAVING SEPARATE BLOCKING PORTIONS ADAPTED TO BE INTERPOSED BETWEEN SAID SPACE AND SAID PLASTICIZER AND BETWEEN SAID SPACE AND SAID ORIFICE, RESPECTIVELY, MEANS FOR MOVING SAID VALVE ELEMENT AND RESPONSIVE TO THE POSITION OF SAID ACCUMULATOR PISTON (1) TO POSITION SAID ELEMENT TO BLOCK COMMUNICATION BETWEEN SAID ACCUMULATOR SPACE AND BOTH SAID ORIFICE AND SAID PLASTICIZER WHEN SAID SPACE IS FULL, (2) TO POSITION SAID ELEMENT TO BLOCK COMMUNICATION BETWEEN SAID SPACE AND SAID ORIFICE WHEN SAID SPACE IS IN COMMUNICATION WITH SAID PLASTICIZER, AND MEANS INDEPENDENT OF THE POSITIONING OF SAID PISTON (3) TO POSITION SAID ELEMENT TO INTERCONNECT SAID SPACE AND SAID ORIFICE WHILE BLOCKING COMMUNICATION BETWEEN SAID SPACE AND SAID PLASTICIZER.