Automatic punch

摘要

A power sheet punching apparatus is provided in which a reversing drive operates initially to drive punches through a stack of sheets and thereafter to reverse direction of the drive to withdraw the punches from the sheets. Should the drive be insufficient to drive the punches through the sheets and a jam occurs, an automatic timer operates to thereafter stop the drive and reverse the drive to withdraw the punches from the sheets, thereby providing an automatic non-jamming punch mechanism.