Apparatus for cold heading blanks

Claim 1

A DOUBLE BLOW HEADER COMPRISING A WORK-RECEIVING DIE ADAPTED TO RECEIVE AN ELONGATED BLANK WITH ONE END PROTRUDING THEREFROM, FIRST AND SECOND TOOLS OPERABLE TO SUCCESSIVELY UPSET THE PROTRUDING END OF SAID BLANK TO FORM A POLYGONAL HEAD THEREON, SAID FIRST TOOL INCLUDING A SLEEVE FORMED WITH A UNIFORM CROSS-SECTION PASSAGE THEREIN, AND A POLYGONAL CROSS-SECTION PUNCH CLOSELY FITTING IN SAID PASSAGE, MOUNTING MEANS MOUNTING SAID SLEEVE FOR AXIAL MOVEMENT RELATIVE TO SAID PUNCH BETWEEN THE FORWARD POSITION TOWARD SAID DIE AND REARWARD POSITIONS SPACED BACK FROM SAID FORWARD POSITION, MEANS MAINTAINING SAID SLEEVE IN SAID FORWARD POSITION AS SAID FIRST TOOL MOVES TOWARD SAID DIE UNTIL THE END OF SAID SLEEVE ENGAGES THE END OF SAID DIE, SAID SLEEVE AND DIE COOPERATING TO DEFINE A POLYGONAL DIE CAVITY CLOSED AT THE END FACE OF SAID DIE BEFORE SAID PUNCH COMPLETES ITS UPSETTING OPERATION, SAID SLEEVE AND DIE BEING FIXED AGAINST RELATIVE MOVEMENT AND COMPLETELY CONFINING SAID PROTRUDING END DURING AT LEAST THE FINAL PORTION OF UPSETTING BY SAID FIRST TOOL, SAID SECOND TOOL BEING FORMED WITH A UNIFORM CROSS-SECTION POLYGONAL DIE CAVITY HAVING SIDE AND END WALLS FIXED AGAINST RELATIVE MOVEMENT DURING ITS ENTIRE UPSETTING OPERATION ON SAID PROTRUDING PORTION, THE CROSS-SECTION OF SAID POLYGONAL DIE CAVITY IN SAID SECOND TOOL BEING GREATER THAN THE CROSS-SECTION OF SAID PASSAGE IN SAID SLEEVE.