Induction heated extruder

Claim 1

A PLASTIC EXTRUDER COMPRISING A BARREL FORMED OF METAL SUSCEPTIBLE TO HEATING BY EDDY CURRENTS, A SCREW ROTATABLY RECEIVED IN SAID BARREL FOR DELIVERY OF PLASTIC THERETHROUGH UNDER PRESSURE TO AN EXTRUDER NOZZLE MENAS FOR CONTROLLING THE TEMPERATURE OF THE PLASTIC WITHIN SAID BARREL INCLUDING A PLURALITY OF LAMINATED FLUX GUIDES DISPOSED ABOUT SAID BARREL WITH INWARDLY TURNED LEGS HAVING ENDS SHAPED TO CONFORM TO THE OUTER SURFACE OF SAID BARREL, MEANS SECURING SAID GUIDE ENDS IN INTIMATE CONTACT WITH THE OUTER SURFACE OF SAID BARREL INCLUDING A PAIR OF SPLIT RINGS, CONNECTING MEANS SECURING SAID LEGS TO SAID RINGS AND SERVING TO PREVENT DELAMINATION OF SAID GUIDES DUE TO THE HEAT OF SAID BARREL, MEANS CLAMPING SAID RINGS TOGETHER IN ENCIRCLING RELATION TO SAID BARREL, AN ALTERNATING CURRENT INDUCTIVE HEATING COIL POSITIONED ABOUT SAID BARREL ADJACENT THE INNER SURFACE OF SAID GUIDES, MEANS SUPPORTING SAID COIL AT THE OUTER PERIPHERY THEREOF ADJACENT THE INSIDE SURFACE OF SAID FLUX GUIDES LEAVING THE INNER PERIPHERY THEREOF UNSUPPORTED AND FREE OF HEAT CONDUCTIVE CONNECTION TO SAID BARREL AND AN ANNULAR PAD OF INSULATING MATERIAL SECURED IN SURROUNDING RELATION ADJACENT THE OUTER SURFACE OF SAID BARREL AND DEFINING AN OPEN AIR SPACE BETWEEN THE OUTER DIMENSION OF SAID MATERIAL AND THE INSIDE SURFACE OF SAID COIL TO INSULATE SAID COIL AGAINST EXCESSIVE HEAT FROM SAID BARREL.