Extrusion head

Claim 1

APPARATUS FOR EXTRUDING SHAPED TUBULAR MEMBERS OF THERMOPLASTIC MATERIAL HAVING A REINFORCING SLEEVE EMBEDDED IN SUCH THERMOPLASTIC MATERIAL COMPRISING A CASING MEANS HAVING A LONGITUDINAL BORE, A MANDREL MOUNTED WITHIN SAID BORE IN CLEARANCE RELATION WITH RESPECT TO THE BORE FOR RECEPTION OF SAID SLEEVE, MEANS, DETACHABLY SECURING SAID MANDREL WITHIN THE BORE AND HOLDING THE SAME AGAINST AXIAL DISPLACEMENT THEREIN, SAID CASING HAVINE DIE MEANS AT THE END THEREOF REMOVE FROM SAID SECURING MEANS, SUPERPOSED GROOVED DRAWING ROLLERS MOUNTED IN FRONT OF SAID DIE, A GAUGE BETWEEN SAID ROLLS FOR RECEIVING SAID SLEEVE WHEREBY MOVEMENT OF THE ROLLS DRAWS SAID SLEEVE TAUT, MEANS FOR FEEDING THERMOPLASTIC MATERIAL INTO SAID BORE TO FLOW OVER AND THROUGH SAID SLEEVE AS THE LATTER IS PULLED BY SAID ROLLS WHEREBY THE EXTRUDED THERMOPLASTIC MATERIAL IS LIKEWISE PULLED THROUGH SAID ROLLS OVER SAID GAUGE, MEANS CONNECTING SAID GAUGE WITH SAID MANDREL, A PORTION OF SAID BORE HAVING PROJECTIONS THEREON EXTENDING TOWARD SAID MANDREL AND SAID MANDREL HAVING PROJECTIONS THEREON ADAPTED TO UNDERLIE SAID FIRST-MENTIONED PROJECTIONS, THE LENGTH OF SAID RESPECTIVE PROJECTIONS BEING SUCH AS TO PROVIDE A CLEARANCE SPACE BETWEEN THE PROJECTIONS FOR ACCOMMODATING SAID SLEEVE WHEREBY SAID PROJECTIONS SPACE SAID SLEEVE FROM SAID MANDREL TO ENSURE THE PROPER POSITIONING OF THE SLEEVE WITHIN SAID THERMOPLASTIC METERIAL BEING EXTRUDED THEREOVER.