Extrusion dies for plastic materials

Claim 1

A DIE HEAD EXTRUDING APPARATUS FOR EXTRUDING PLASTIC MATERIAL COMPRISING A BODY HAVING A CHAMBER THAT IS ADAPTED TO RECEIVE UNDER PERSSURE SAID MATERIAL TO BE EXTRUDED AND A SUBSTANTIALLY CYLINDRICAL BORE, A NOZZLE HOLDER HAVING A SUBSTANTIALLY CYLINDRICAL PORTION ROTATABLY MOUNTED WITHIN SAID CHAMBER BORE BETWEEN A FRIST POSITION AND A SECOND POSITION, SAID HOLDER HAVING A SLOTTED INTERMEDIATE PORTION, A SEPARATE NOZZLE ASSEMLBY MOUNTED ACROSS THE SLOTTED INTERMEDIATE PORTION AND DIVIDING SAID CHAMBER INTO AN UPPER AND A LOWER CHAMBER SECTION AND HAVING MEANS FOR PASSING THE EXTRUDABLE MATERIAL FROM SAID UPPER CHAMBER SECTION TO SAID LOWER CHAMBER SECION, SAID NOZZLE ASSEMLBY BEING RIGIDLY CONNECTED WITHIN SAID HOLDER, AND MEANS FOR ROTATING SAID HOLDER APPROXIMATELY 180* BETWEEN SAID FIRST AND SECOND POSITION IN RELATION TO SAID CHAMBER WHEREBY THE DIRECTION OF THE NOZZLE ASSEMBLY IN RELATION TO THE DIRECTION OF FLOW OF SAID EXTRUDABLE MATERIAL IS DIAMETRICALLY REVERSED THEREBY TO CLEAR BLOCKING MATERIAL FROM SAID NOZZLE.