Extrusion of metals

Claim 1

PROCESS FOR EXTENDING METALLIC SUBSTANCES SUSCEPTIBLE TO DETRIMENTAL ALTERATION AT THE TEMPERATURE OF EXTRUSION BY CONTACT WITH THE ATMOSPHERE AND THE METALLIC WORKING PARTS OF AN EXTRUSION PRESS, CONPRISING THE STEPS OF: FASTENING A DIE BLOCK INSIDE THE LOWER END OF A PROTECTIVE SLEEVE; PLACING AN EXTRUSION DIE, A BILLET TO BE EXTRUDED, AND A DUMMY BLOCK, IN THE ORDER NAMED, ON TOP OF SAID DIE BLOCK INSIDE SAID SLEEVE, AT LEAST THE INNER SURFACE OF SAID SLEEVE AND THE WORKING SURFACE OF DIE BEING NON-REACTIVE TO THE MATERIAL OF THE BILLET AT THE TEMPERATURE OF EXTRUSION; INSERTING THE AFOREMENTIONED SLEEVE ASSEMBLY INSIDE THE CONTAINER OF AN EXTRUSION PRESS, AND ON TOP OF A SUPPORT PROVIDED WITH A CONTROLLABLE APERTURE; APPLYING PRESSURE TO THE BILLET TO FORCE THE SAME FROM ITS SLEEVE AND SIMULTAUEOUSLY EXTRUDE IT THROUGH THE DIE TO OBTAIN AN EXTRACT ARTICLE OF THE DESIRED SHAPE; AND UPON COMPLETION OF THE EXTRUSION OPERATION, INCREASING THE OPENING OF SAID APERTURE, TO PERMIT PASSING OF THE SLEEVE ASSEMBLY THERETHROUGH.