Fastener driving apparatus

Claim 1

A FASTENER DRIVING APPARATUS COMPRISING A HOUSING DEFINING A CHAMBER ADAPTED TO CONTAIN COMPRESSED FLUID, CYLINDER MEANS HAVING AN OPEN END ADAPTED FOR EXPOSURE TO THE COMPRESSED FLUID IN SAID CHAMBER AND AN OPPOSITE END IN CONTINUAL OPEN COMMUNICATION WITH THE ATMOSPHERE, FIRST VALVE MEANS ADJACENT THE OPEN END OF SAID CYLINDER MEANS AND COOPERATING THEREWITH TO OPEN AND CLOSE COMMUNICATION BETWEEN SAID CHAMBER AND SAID CYLINDER MEANS , PISTON MEANS IN SAID CYLINDER MEANS MOVABLE THEREIN BETWEEN SAID ENDS, PASSAGE MEANS FORMED IN SAID PISTON MEANS COMMUNICATING BETWEEN OPPOSITE ENDS THEREOF TO PERMIT FLUID FLOW THROUGH SAID PISTON MEANS BETWEEN THE ENDS OF SAID CYLINDER MEANS, SECOND VALVE MEANS IN SAID PASSAGE MEANS, SAID SECOND VALVE MEANS FLUID OPERATED TO CLOSE SAID PASSAGE MEANS WHEN SAID FIRST VALVE MEANS IS OPENED TO EXPOSE THE OPEN END OF SAID CYLINDER MEANS TO SAID COMPRESSED FLUID AND MEANS IN SAID PISTON MEANS FOR BYPASSSING FLUID AROUND SAID SECOND VALVE MEANS BETWEEN SAID OPEN END AND SAID OPPOSITE END OF SAID CYLINDER MEANS.