Abstract: A miniature pneumatic punch for a strip of photographic print paper, to punch a hole between adjacent photographs at the exposure stage of the printing process. The punch comprises a cylinder body having a chamber and a piston seated within to be pneumatically driven between upper and lower limits in the chamber. For this purpose, actuation and retraction air inlet ports are provided through the wall of the chamber. Fluid communication within the cylinder chamber between the ports is prevented by the piston. An elongated guide of constant cross-section is secured centrally to the piston on the side thereof exposed to the air from the retraction air inlet port. A passageway is provided through the cylinder body below the chamber, the passageway being of constant crosssectional and flushly receiving the guide for sliding movement therein. An elongated punch of the same or less crosssection dimension than the guide is centrally secured to the free end of the guide.

Abstract: A pneumatic punch for paper, and particularly photographic paper. The punch comprises a cylinder having a piston seated within, to be pneumatically driven between upper and lower limits in the cylinder chamber. For this purpose, actuation and retraction air inlet ports are provided through the wall of the cylinder, the ports being separated by the piston against fluid communication within the cylinder chamber between the ports. An elongated guide of constant, circular cross-section is secured centrally to the piston on the side thereof exposed to the air from the retraction air inlet port. An elongated punch of circular cross-section is concentrically secured to the free end of the guide. A central relatively restricted air passageway extends from the actuation air inlet port side of the piston, passing through the piston, guide and punch. A die cooperates with the punch, the die having a body rigidly associated with the cylinder and having a slot of circular cross-section to receive the punch.