Perforation of sheet material

Claim 1

A HIGH SPEED PERFORATING APPARATUS COMPRISING A STATIONARY DIE, AN OPENING IN SAID DIE HAVING A MARGINAL SHEET-ENGAGING EDGE, A PUNCH SLEEVE IN ALIGNMENT WITH THE DIE OPENING SAID HAVING A CYLINDRICAL BORE, MEANS MOUNTING THE PUNCH SLEEVE FOR MOVEMENT VERTICALLY TOWARD AND AWAY FROM SAID OPENING, A WORK-ENGAGING MEMBER MOUNTED IN THE END PORTION OF SAID SLEEVE AND HAVING A CONVEX NOSE PORTION PROJECTING BEYOND THE SLEEVE AND HAVING A CONVEX THE EDGE OF THE DIE OPENING, SAID NOSE PORTION BEING LARGER THAN SAID OPENING AND RECEDING FROM ITS TERMINUS, YIELDABLE MEANS FOR BIASING AND WORK-ENGAGING MEMBER TOWARD A NORMAL POSITION AT THE END OF THE PUNCH SLEEVE COMPRISING AN AXIALLY ELONGATED INSERT OF ELASTOMERIC RUBBER, A FIRST AXIALLY ELONGATED RIGID MEMBER MOUNTED THE BORE OF SAID PUNCH SLEEVE FOR LIMITED VERTICAL SLIDING MOVEMENT RELATIVE TO SAID SLEEVE, SAID INSERT BEING LOCATED IN SAID BORE BETWEEN SAID RIGID MEMBER AND SAID WORKENGAGING MEMBER TO BIAS THE RIGID MEMBER AWAY FROM THE WORK-ENGAGING MEMBER TO A NORMAL POSITION IN ENGAGEMENT WITH A RIGID PORTION OF THE PUNCH SLEEVE, SAID INSERT RESISTING MOVEMENT OF SAID RIGID MEMBER AND SAID WORK-ENGAGING MEMBER OUT OF THEIR NORMAL POSITIONS RELATIVE TO SAID PUNCH SLEEVE, A SECOND AXIALLY ELONGATED RIGID MEMBER MOUNTED IN THE BORE OF THE PUNCH SLEEVE BETWEEN SAID INSERT AND SAID WORK-ENGAGING MEMBER FOR VERTICAL SLIDING MOVEMENT RELATIVE TO THE PUNCH SLEEVE, EACH OF SAID RIGID MEMBERS BEING IN THE FORM OF A SOLID METAL CYLINDER SLIDABLY MOUNTED FOR RECIPROCATION IN SAID BORE, AND MEANS FOR RECIPORCATING THE PUNCH SLEEVE AT HIGH BELOCITY TO CAUSE THE NOSE PORTION OF THE WORK-ENGAGING MEMBER TO ENGAGE THE MARGINAL EDGE OF THE DIE OPENING SUBSTANTIALLY THROUGHOUT THE PERIMETER THEREOF AND TO PINCH OFF THE MATERIAL BETWEEN THE PUNCH SLEEVE AND THE DIE.