Apparatus for making electric cables with extruded insulation

Claim 1

AN EXTRUSION HEAD ASSEMBLY FOR THE MANUFACTURE OF ELECTRIC CABLE COMPRISING A CONDUCTOR INSULATED BY A LAYER OF INSULATING MATERIAL SANDWICHED BETWEEN INNER AND OUTER LAYERS OF SEMI-CONDUCTIVE MATERIAL, SAID ASSEMBLY COMPRISING FOUR INTERFITTING TIP AND DIE UNITS HAVING FIRST AND SECOND ANNULAR EXTRUSION ORIFICES DEFINED RESPECTIVELY BETWEEN THE FIRST AND SECOND UNITS AND BETWEEN THE THIRD AND FOURTH UNITS FOR EXTRUSION OF THE SEMI-CONDUCTIVE LAYERS AND A THIRD ANNULAR EXTRUSION ORFICE DEFINED BETWEEN THE SECOND AND THIRD UNITS AND POSITIONED BETWEEN THE OTHER TWO ORFICES FOR EXTRUSION OF THE INSULANT BETWEEN SAID LAYERS, EACH ORFICE BEING FORMED BETWEEN A COOPERATING TIP AND DIE BELONGING RESPECTIVELY TO THE INNER AND OUTER OF THE TWO TIP AND DIE UNITS BETWEEN WHICH IT IS DEFINED, AND THE ASSEMBLY FURTHER INCLUDING FIRST AND SECOND INLET PORTS THROUGH THE FIRST, OUTERMOST, UNIT FOR RESPECTIVELY RECEIVING SEMI-CONDUCTIVE EXTRUSION MATERIAL AND THE INSULATING EXTRUSION MATERIAL, SAID INLET PORTS BEING LOCATED UPSTREAM OF THE POSITION OF THE EXTRUSION ORIFICES, SHAPED PASSTAGES DEFINED BY FACING SURFACES OF THE FIRST AND SECOND UNITS AND COMMUNICATING BETWEEN SAID FIRST INLET PORT AND THE EXTRUSION ORIFICE DEFINED BETWEEN THESE UNITS, FIRST AND SECOND THROUGH-PORTS IN THE SECOND UNIT N COMMUNICATION RESPECTIVELY WITH THE FIRST AND SECOND INLET PORTS, SHAPED PASSAGES DEFINED BY FACING SURFACES OF THE SECOND