Abstract: A sliding block with a female die acts in conjunction with a four bar linkage mounted block with a male die to punch indexing holes in a moving metal strip. The block with male die continually seeks to rotate, but is held in position by the sliding block. The sliding block is programmed to periodically move forward at the speed of the moving metal strip and to return to starting position. This frees the male die to rotate to punch out the hole, and to continue to rotate back into the starting position to be held by the returned sliding block.

Abstract: A strip of metal under tension is driven over an anvil wheel where the strip is contoured by a milling cutter. The moving strip is punched to provide an indexing hole. The milling cutter is programed to advance toward or to retract from the anvil wheel based upon the linear travel of the metal strip, and the punch is activated based upon the linear travel of the strip.