Extruder

Claim 1

IN AN EXTRUDER A DIEHEAD, SAID DIEHEAD INCLUDING (A) TWO ELONGATED CONCENTRICALLY ARRANGED PARTS OF ANNULAR CROSS-SECTION, SAID CONCENTRIC PARTS BEING STATIONARY, HAVING AN AXIS, AND DEFINING THEREBETWEEN AN AXIALLY EXTENDING ANNULAR PASSAGE FOR THE FLOW OF EXTRUDED PLASTICS, (B) A DIE MEMBER SUPPORTED BY ONE OF SAID PARTS, HAVING A RADIALLY EXTENDING FACE, AND AN OPENING IN SAID END FACE, (C) A MANDREL MEMBER EXTENDING INTO SAID OPENING AND HAVING A RADIALLY EXTENDING END FACE, BOTH OF SAID END FACES LYING IN A RADIALLY EXTENDING COMMON PLANE, SAID DIE MEMBER AND SAID MANDREL MEMBER FORMING AN EXTRUSION NOZZLE AND DEFINING AN ANNULAR EXTRUSION ORIFICE OPENING IN SAID COMMON PLANE, SAID PASSAGE TERMINATING IN SAID EXTRUSION ORIFICE, (D) A TUBULAR MEMBER HAVING AN EDGE, SAID TUBULAR MEMBER BEING MOUNTED ON ONE OF SAID DIE AND MANDREL MEMBERS FOR AXIAL MOVEMENTS RELATIVE TO SAID DIE AND MANDREL MEMBERS TO VARY THE SIZE OF SAID EXTRUSION ORIFICE, AND EXTENDING OVER A FRACTION OF THE ELONGATED OF SAID CONCENTRIC PARTS, AND (E) ACTUATING MEANS FOR AXIALLY MOVING SAID TUBULAR MEMBER FROM A POSITION IN WHICH SAID EDGE IS SUBSTANTIALLY FLUSH WITH SAID COMMON PLANE TO A RETRACTED POSITION, AND VICE VERSA, SAID ACTUATING MEANS INCLUDING A SLIDABLY MOUNTED ROD MEMBER AND A CONNECTING MEMBER, SAID ROD MEMBER BEING PROVIDED WITH A RADIALLY EXTENDING APERTURE, SAID MANDREL MEMBER BEING PROVIDED WITH OPPOSITE LONGITUDINALLY EXTENDING SLOTS, SAID CONNECTING MEMBER PASSING THROUGH SAID APERTURE AND SAID SLOTS AND HAVING END PORTIONS THEREOF FASTENED TO SAID TUBULAR MEMBER, ABUTMENT MEANS LIMITING THE SLIDING MOVEMENT OF SAID ROD MEMBER AND SAID CONNECTION MEMBER, SAID ABUTMENT MEANS BEING CONSTITUTED BY END WALLS DEFINING SAID SLOTS.