Plastic extruding machine

Claim 1

IN OR FOR A PLASTIC EXTRUDIGN MACHINE OF THE ROTARY SCREW CONVEYOR TYPE, A PERFORATED UNIT THROUGH WHICH THE PLASTIC MATERIAL IS FORCED BY THE ROTARY SCREW CONVEYOR AND COMPRISING AN OPEN MESH SCREEN AND A SUPPORTING PLATE MAKING FACE CONTACT THEREWITH AND FORMED WITH A MULTIPLICITY OF THROUGH HOLES DISTRIBUTED OVER ITS EFFECTIVE AREA, SAID SUPPORTING PLATE ALSO HAVING A SOLID CENTER PORTION FOR SUPPORTING A DIE CORE ON THE OUTLET SIDE OF THE PERFORATED UNIT AS WELL AS A CONE SHAPED PROTUBERANCE ON THE ENTRANCE SIDE THEREOF AND EXTENDING UPSTREAM THEREFROM, SAID CONE SHAPED PROTUBERANCE HAVING ITS CONICAL SURFACE TERMINATING IN A BASE WHICH COVERS THE WHOLE AREA OF THE SOLID CENTER PORTION OF THE SUPPORTING PLATE, SAID SCREW CONVEYOR TERMINATING IN AN IMPELLER COOPERATING WITH THE PERFORATED UNIT TO FORCE THE MATERAIL THERETHROUGH AND HAVING A CUTTING EDGE WHICH SEVERS THE MATERIAL ON THE ENTRANCE SIDE OF THE PERFORATED UNIT AS IT ENTERS THE PERFORATIONS THEREOF, SAID IMPELLER BEING FORMED WITH A CENTER RECESS TO ACCOMMODATE THE CONE SHAPED PROTUBERANCE, SAID REECESS AFORDING ENOUGH CLEARANCE TO AVOID CONTACT WITH THE PROTUBERANCE UNDER ALL CONDITIONS OF USE OF THE MACHINE, SAID CONICAL SURFACE BEING FREE THROUGHOUT ITS WHOLE AREA TO PERMIT THE MATE RIAL ADVANCED UNDER THE PROPELLING FORCE OF THE SCREW CONVEYOR TO COME IN CONTACT THEREWITH THROUGHOUT SAID WHOLE AREA AND TO CAUSE THEREBY THE CONTACTING MATERIAL TO BE ADVANCED DOWNSTREAM AND ALONG SAID CONICAL SURFACE TOWARDS THE PERFORATIONS IN SAID UNIT BY THE PROPELLING FORCE OF THE SCREW CONVEYOR, THUS PREVENTING THE MATERIAL IN THE DEAD AREA OF THE PERFORATED UNIT FROM BECOMING STATIC AND BURNING.