Process and apparatus for extruding ribbed plastic material sections

Claim 1

AN EXTRUSION DIE COMPRISING AN OUTER MEMBER HAVING AN ENDLESS WALL SURROUNDING AN INNER CAVITY, AN INNER MEMBER POSITIONED IN SAID CAVITY AND SPACED FROM SAID ENDLESS WALL TO FORM AN ENDLESS ANNULAR SPACE THEREWITH AND SAID SPACE TERMINATING IN A DOWNWARDLY EXTRUDING ORIFICE, MEANS FOR DELIVERING MATERIAL TO BE EXTRUDED TO SAID ANNULAR SPACE FOR EXTRUSION DOWNWARDLY THROUGH SAID ORIFICE, A FIRST CONDUIT CONNECTED TO SAID ANNULAR SPACE FOR RECEIVING THEREFROM A PORTION OF THE MATERIAL BEING EXTRUDED, A SECOND CONDUIT CONNECTED WITH SAID FIRST CONDUIT AND CONDUCTING EXTRUDING MATERIAL TO A DISCHARGE CONDUIT OPENING A VALVE CONNECTED TO SAID SECOND CONDUIT FOR REGULATING THE RATE OF FLOW THROUGH SAID SECOND CONDUIT, SAID FIRST AND SECOND CONDUITS BEING FIXED RELATIVE TO SAID ANNULAR SPACE, SAID DISCHARGE OPENING BEING SPACED FROM THE EXTRUDING ORIFICE A DISTANCE SUBSTANTIALLY GREATER THAN THE DIAMETER OF THE SECOND CONDUIT AND BEING ARRANGED IN PROXIMITY TO THE EXTRUDED MATERIAL TO DEPOSIT THE MATERIAL BEING DISCHARGED FROM THE CONDUIT ONTO THE MATERIAL BEING DISCHARGED FROM SAID EXTRUDING ORIFICE, SAID CONDUITS BEING OF A DIAMETER WHICH WILL ALLOW EXTRUDED MATERIAL TO BE DISCHARGED DOWNWARDLY AT A FASTER LINEAR RATE FROM THE CONDUIT OPENING THAN THE MATERIAL BEING DISCHARGED FROM THE EXTRUDING ORIFICE TO UNDULATE THE MATERIAL FROM THE CONDUIT OPENING WHEN BEING JOINED WITH THE EXTRUDED MATERIAL DISCHARGED FROM THE EXTRUDING ORIFICE.