Apparatus for selectively controlling the extrusion of plastic material

Claim 1

AN APPARATUS FOR EXTRUDING A GENERALLY TUBULAR FORMATION OF PLASTIC MATERIAL THROUGH AN EXTRUSION OUTLET DEFINED BY SPACED SURFACE MEANS, SAID APPARATUS COMPRISING: MEANS DEFINING A CAVITY PROVIDING CONTINUOUS COMMUNICATION BETWEEN A MASS OF PLASTIC MATERIAL AND SAID EXTRUSION OUTLET; MEANS FOR APPLYING AN INITIAL PRESSURE TO SAID MASS OF PLASTIC MATERIAL TO INITIATE ITS FLOW THROUGH SAID CAVITY AND FOR CONTINUOSLY MAINTAINING AN APPLICATION OF INITIAL PRESSURE SO AS TO MAINTAIN A CONTINUOUS FLOW OF MATERIAL ENTERING SAID CAVITY; FIRST MEANS FOR VARYING THE CAPACITY OF SAID CAVITY SO AS TO VARY THE RATE AT WHICH SAID MATERIAL REACHES SAID OUTLET AND THE PRESSURE AT WHICH SAID MATERIAL IS EXTRUDED THERETHROUGH TO FORM A PARISON WHILE THE CAPACITY OF SAID CAVITY IS BEING VARIED SO AS TO EFFECT THE EXTERNAL SIZE OF SAID PARISON; SECOND MEANS FOR VARYING THE POSITIONAL RELATIONSHIP OF THE SURFACE MEANS DEFINING SAID OUTLET WHILE THE CAPACITY OF SAID CAVITY IS BEING VARIED SO AS TO EFFECT THE INTERNAL SIZE OF SAID PARISON; AND CONTROL MEANS FOR CAUSING THE SIMULTANEOUS OPERATION OF SAID FIRST AND SECOND MEANS DURING A PORTION OF THE PERIOD DURING WHICH A PARISON IS BEING EXTRUDED SO AS TO SIMULTANEOUSLY AFFECT THE EXTERNAL SIZE AND INTERNAL SIZE OF A PORTION OF SAID PARISON.

Claim 2

AN APPARATUS FOR EXTRUDING A GENERALLY TUBULAR FORMATION OF PLASTIC MATERIAL THROUGH AN EXTRUSION OUTLET DEFINED BY SPACED SURFACE MEANS, SAID APPARATUS COMPRISING: MEANS DEFINING A CAVITY PROVIDING CONTINUOUS COMMUNICATION BETWEEN A MASS OF PLASTIC MATERIAL AND SAID EXTRUSION OUTLET; MEANS FOR APPLYING AN INITIAL PRESSURE TO SAID MASS OF PLASTIC MATERIAL TO INITIATE ITS FLOW THROUGH SAID CAVITY AND FOR CONTINUOSLY MAINTAINING AN APPLICATION OF INITIAL PRESSURE SO AS TO MAINTAIN A CONTINUOUS FLOW OF MATERIAL ENTERING SAID CAVITY; FIRST MEANS FOR VARYING THE CAPACITY OF SAID CAVITY SO AS TO VARY THE RATE AT WHICH SAID MATERIAL REACHES SAID OUTLET AND THE PRESSURE AT WHICH SAID MATERIAL IS EXTRUDED THERETHROUGH TO FORM A PARISON WHILE THE CAPACITY OF SAID CAVITY IS BEING VARIED SO AS TO EFFECT THE EXTERNAL SIZE OF SAID PARISON; SECOND MEANS FOR VARYING THE POSITIONAL RELATIONSHIP OF THE SURFACE MEANS DEFINING SAID OUTLET WHILE THE CAPACITY OF SAID CAVITY IS BEING VARIED SO AS TO EFFECT THE INTERNAL SIZE OF SAID PARISON; AND CONTROL MEANS FOR CAUSING THE SIMULTANEOUS OPERATION OF SAID FIRST AND SECOND MEANS DURING A PORTION OF THE PERIOD DURING WHICH A PARISON IS BEING EXTRUDED SO AS TO SIMULTANEOUSLY AFFECT THE EXTERNAL SIZE AND INTERNAL SIZE OF A PORTION OF SAID PARISON.