Press for tubular extrusion

Claim 1

A PRESS FOR EXTRUDING A METAL COVERING ON AN ELECTRICAL CABLE CORE COMPRISING A CHAMBER FOR CONTAINING METAL TO BE EXTRUDED, A COACTING EXTRUSION DIE AND CORE TUBE SITUATED WITHIN SAID CHAMBER, SAID DIE AND CORE TUBE EACH HAVING AN INNER BORE, SAID DIE AND CORE TUBE INNER BORES BEING CENTERED ABOUT COINCIDENT AXES, THE BORE OF SAID DIE BEING LARGER THAN THE BORE OF SAID CORE TUBE, THE OUTER SURFACE OF THE PORTION OF SAID CORE TUBE ADJACENT TO SAID DIE BEING IN THE FORM OF A FIRST RIGHT, CIRCULAR, CONICAL FRUSTRUM HAVING ITS AXIS COINCIDENT WITH THE AXIS OF THE BORE OF SAID CORE TUBE AND HAVING THE EDGE OF ITS SMALLER DIAMETER BASE COINCIDENT WITH THAT END OF THE BORE OF SAID CORE TUBE WHICH IS ADJACENT TO SAID DIE, SAID OUTER SURFACE FORMING AN ANGLE OF BETWEEN 20* AND 45* WITH ITS AXIS, THE END OF THE DIE ADJACENT TO SAID CORE TUBE HAVING AN OPENING CONSTITUTING AN ENLARGEMENT OF THE BORE OF SAID DIE, SAID OPENING BEING IN THE FORM OF A SECOND RIGHT, CIRCULAR, CONICAL FRUSTRUM HAVING ITS AXIS ON THE SAME LINE AS THE BORE AND HAVING THE EDGE OF ITS SMALLER DIAMETER BASE COINCIDENT WITH THE EDGE OF SAID DIE BORE, THE SURFACE OF SAID SECOND CONICAL FRUSTRUM FORMING AN ANGLE WITH THE AXIS OF SAID SECOND CONICAL FRUSTRUM WHICH IS BETWEEN 5* AND 10* LARGER THAN THE ANGLE FORMED BY THE SURFACE OF SAID FIRST CONICAL FRUSTRUM, THE OUTER SURFACE OF THE PORTION OF SAID DIE ADJACENT TO SAID CORE TUBE BEING IN THE FORM OF A THIRD RIGHT, CIRCULAR, CONICAL FRUSTRUM HAVING ITS AXIS COINCIDENT WITH THE AXIS OF THE DIE BORE AND HAVING THE EDGE OF ITS SMALLER DIAMETER BASE COINCIDENT WITH THE EDGE OF THE LARGER DIAMETER BASE OF SAID SECOND CONICAL FRUSTRUM THE SURFACE OF SAID THIRD CONICAL FRUSTRUM FORMING AN ANGLE OF BETWEEN 30 AND 60* WITH THE AXIS OF SAID THIRD CONICAL FRUSTRUM, THE LENGTH OF SAID SECOND CONICAL FRUSTRUM ALONG ITS CONICAL SURFACE FROM ITS LARGER BASE TO ITS SMALLER BASE BEING BETWEEN ABOUT 5 MILS AND ABOUT 50 MILS.