Method for making hollow articles

Claim 1

THE METHOD OF MAKING A HOLLOW ARTICLE HAVING AN OUTER BORE OF LESSER DIAMETER THAN AN INNER BORE, COMPRISING CUTTING A WORKPIECE FROM A LENGTH OF SOLID STOCK, CONFINING THE WORKPIECE IN A SUBSTANTIALLY UNIFORM CAVITY OF A PREDETERMINED DEPTH IN A DIE, DRIVING AN EXTRUDING PIN INTO THE WORKEPIECE TO EXTRUDE A PORTION OF THE WORKPIECE REARWARDLY AROUND THE EXTRUDING PIN TO FROM AN ELONGATED WORKPIECE HAVING A CYLINDER BORE EXTENDING INTO THE WORKPIECE FROM ONE END THEREOF, INCREASING THE EFFECTIVE DEPTH OF THE CAVITY AT A REDUCE DIAMETER, DRIVING A MANDREL INTO THE INITIAL PORTIONS OF THE BORE IN THE WORKPIECE AND DRIVING A PORTION OF THE WORKPIECE INTO THE DEEPENED CAVITY OF LESSER DIAMETER BY PRESSURE APPLIED TO THE END OF THE WORKPIECE THROUGH AN EXTRUDING PUNCH WHILE MAINTAINING THE MADREL IN THE BORE TO PREVENT COLLAPSE OF THE BORE AND TO EXTRUDE AND LENGTHEN THE WORKPIECE IN THE CAVITY OF LESSER DIAMETER AND FORM A PERIPHERAL SHOULDER AT THE OUTER END OF THE WORKPIECE STRIPPING THE WORKPIECE FROM THE MADREL, EJECTING THE WORKPIECE FROM THE DIE CAVITY, TRANSFERRING THE WORKPIECE TO A SECOND DIE, DRIVING THE WORKPIECE INTO A CAVITY IN THE SECOND DIE WHOSE DIAMETER IS LESS THAN THE DIAMETER OF THE PREVIOUSLY-FORMED SHOULDER ON THE WORKPIECE BY PRESSURE APPLIED TO THE END OF THE WORKPIECE THROUGH A TRIMMING PUNCH TO TRIM A PORTION OF THE SHOULDER FROM THE WORKPIECE, SPLITTING THE TRIMMED PORTION WHILE THE WORKPIECE IS WHOLLY WITHIN THE CAVITY IN THE SECOND DIE, PARTIALLY EJECTING THE WORKPIECE FROM THE SECOND DIE AND HOLDING IT IN THE PARTIALLY EJECTED POSITION, IRONING THE REMAINING SHOULDER INTO THE WORKPIECE BY PRESSURE APPLIED TO THE SHOULDER THROUGH AN IRONING PUNCH TO PROVIDE A UNIFORM OUTSIDE DIAMETER ALONG THE LENGTH OF THE WORKPIECE AND TO DECREASE THE DIAMETER OF THE BORE IN THE WORKPIECE FOR A LENGTH APPROXIMATELY EQUAL TO THE LENGTH OF THE PREVIOUSLY-FORMED SHOULDER, DRIVING THE WORKPIECE OUT OF THE IRONING PUNCH BY PRESSURE APPLIED TO THE END OF THE WORKPIECE THROUGH A KNOCKOUT ROD WITHIN IRONING PUNCH, AND EJECTING THE FINISHED ARTICLE FROM THE SECOND DIE.

Claim 2

THE METHOD OF MAKING A HOLLOW ARTICLE HAVING AN OUTER BORE OF LESSER DIAMETER THAN AN INNER BORE, COMPRISING CUTTING A WORKPIECE FROM A LENGTH OF SOLID STOCK, CONFINING THE WORKPIECE IN A SUBSTANTIALLY UNIFORM CAVITY OF A PREDETERMINED DEPTH IN A DIE, DRIVING AN EXTRUDING PIN INTO THE WORKEPIECE TO EXTRUDE A PORTION OF THE WORKPIECE REARWARDLY AROUND THE EXTRUDING PIN TO FROM AN ELONGATED WORKPIECE HAVING A CYLINDER BORE EXTENDING INTO THE WORKPIECE FROM ONE END THEREOF, INCREASING THE EFFECTIVE DEPTH OF THE CAVITY AT A REDUCE DIAMETER, DRIVING A MANDREL INTO THE INITIAL PORTIONS OF THE BORE IN THE WORKPIECE AND DRIVING A PORTION OF THE WORKPIECE INTO THE DEEPENED CAVITY OF LESSER DIAMETER BY PRESSURE APPLIED TO THE END OF THE WORKPIECE THROUGH AN EXTRUDING PUNCH WHILE MAINTAINING THE MADREL IN THE BORE TO PREVENT COLLAPSE OF THE BORE AND TO EXTRUDE AND LENGTHEN THE WORKPIECE IN THE CAVITY OF LESSER DIAMETER AND FORM A PERIPHERAL SHOULDER AT THE OUTER END OF THE WORKPIECE STRIPPING THE WORKPIECE FROM THE MADREL, EJECTING THE WORKPIECE FROM THE DIE CAVITY, TRANSFERRING THE WORKPIECE TO A SECOND DIE, DRIVING THE WORKPIECE INTO A CAVITY IN THE SECOND DIE WHOSE DIAMETER IS LESS THAN THE DIAMETER OF THE PREVIOUSLY-FORMED SHOULDER ON THE WORKPIECE BY PRESSURE APPLIED TO THE END OF THE WORKPIECE THROUGH A TRIMMING PUNCH TO TRIM A PORTION OF THE SHOULDER FROM THE WORKPIECE, SPLITTING THE TRIMMED PORTION WHILE THE WORKPIECE IS WHOLLY WITHIN THE CAVITY IN THE SECOND DIE, PARTIALLY EJECTING THE WORKPIECE FROM THE SECOND DIE AND HOLDING IT IN THE PARTIALLY EJECTED POSITION, IRONING THE REMAINING SHOULDER INTO THE WORKPIECE BY PRESSURE APPLIED TO THE SHOULDER THROUGH AN IRONING PUNCH TO PROVIDE A UNIFORM OUTSIDE DIAMETER ALONG THE LENGTH OF THE WORKPIECE AND TO DECREASE THE DIAMETER OF THE BORE IN THE WORKPIECE FOR A LENGTH APPROXIMATELY EQUAL TO THE LENGTH OF THE PREVIOUSLY-FORMED SHOULDER, DRIVING THE WORKPIECE OUT OF THE IRONING PUNCH BY PRESSURE APPLIED TO THE END OF THE WORKPIECE THROUGH A KNOCKOUT ROD WITHIN IRONING PUNCH, AND EJECTING THE FINISHED ARTICLE FROM THE SECOND DIE.