Method of and means for producing openwork structures of thermoplastic material

Claim 1

APPARATUS FOR FABRICATING OPENWORK STRUCTURES OF A THERMOPLASTIC MATERIAL COMPRISING A SUPPORT; AN INNER FIXED DIE MOUNTED ON THE SUPPORT AND FORMED WITH A RING OF LINEAR EXTRUSION PASSAGES TERMINATING WITH A SET OF CO-PLANAR, PARALLEL EXTRUSION ORIFICES ON ONE SIDE OF SAID FIXED DIE; AN OUTER DIE CONCENTRIC WITH AND ROTATABLE ABOUT THE INNER FIXED DIE, THE OUTER DIE BEING FORMED WITH A FURTHER RING OF LINEAR EXTRUSION PASSAGES CONCENTRIC WITH THE RING OF PASSAGES OF THE FIXED DIE AND TERMINATING ON ONE SIDE OF THE OUTER DIE WITH A SET OF PARALLEL EXTRUSION ORIFICES CO-PLANAR WITH AND LATERALLY SPACED FROM THE SET OF ORIFICES OF THE INNER FIXED DIE; MEANS FOR SUPPLYING FLUENT THERMOPLASTIC MATERIAL TO THE DIES AND THE EXTRUSION PASSAGES THEREOF TO PRODUCE INDIVIDUAL AND DISTINCT EXTRUDED PLASTIC STREAMS THROUGH ALL OF THE SAID ORIFICES; MEANS FOR ROTATING THE OUTER DIE ABOUT THE INNER DIE; AND A MECHANICAL GUIDE CONE COAXIAL WITH AND AXIALLY SPACED FROM THE DIES AND THE ORIFICES THEREOF, THE SURFACE OF THE CONE TAPERING TOWARD THE DIES AND DIMENSIONED TO ENGAGE THE STREAMS EXTRUDED FROM THE ORIFICES OF THE INNER FIXED DIE AND DIRECT THE SAID INNER DIE STREAMS TOWARD THE MOVING STREAMS EXTRUDED FROM THE OUTER ROTATING DIE FOR PERIODIC FUSION CONTACT THEREWITH.