Pneumatic fastener driving machine

Claim 1

IN A FASTENERE-APLYING MACHINE THE COMBINATION COMPRISING A RESERVOIR FOR PRESSURE FLUID, A CYLINDER HAVING AN INLET PORT COMMUNICATING WITH SAID RESERVOIR, A PISTON RECIPROCABLE IN SAID CYLINDER, A VALVE MOVABLE TO OPEN AND CLOSE SAID INLET PORT, AN EXHAUST TUBE MOVABLE WITH SAID INLET VALVE AND ADAPTED TO COMMUNICATE AT OPPOSITE ENDS THEREOF RESPECTIVELY WITH SAID CYLINDER AND WITH ATMOSPHERE, MEANS FOR SLIDABLY GUIDING SAID TUBE AND FOR OPENING AND CLOSING THE ATMOSPHERE END OF SAID TUBE IN REPONSE RESPECTIVELY TO CLOSING AND OPENING MOVEMENT OF SAID INLET VALVE, SAID LAST-MENTIONED MEANS COMPRISING A SLEEVE ANDA CLOSURE CAP DEFINING AN EXHAUST CHAMBER THEREBETWEEN COMMUNICATING WITH ATMOSPHERE, SAID CAP DEFINING AN END WALL OF SAID EXHAUST CHAMBER DISPOSED PERPENDICULAR TO THE AXIS OF SAID TUBE AGAINST WHICH SAID ATMOSPHERE END OF THE TUBE AXIALLY ABUTS TO CLOSE THE SAME, SAID TUBE BEING SLIDABLY SUPPORTED IN SAID SLEEVE WITH SAID ATMOSPHERE END OF SAID TUBE PROJECTING AXIALLY THEREFROM INTO SAID EXHAUST CHAMBER IN RADIALLY SPACED RELATION FROM THE RADIALLY SURROUNDING WALL OF SAID EXHAUST CHAMBER ,SAID TUBE HAVING A PRESSURE SURFACE EXPOSED VIA THE INTERIOR OF SAID TUBE TO PRESSURE FLUID IN TE CYLINDER WHEN SAID TUBE IS CLOSED AND DISPOSED TO DEVELOP AN OPENING FORCE ON SAID TUBE, SAID INLET VALVE HAVING PRESSURE SURFACE EXPOSED TO RESERVOIR PRESSURE FLUID FOR HOLDING SAID INLET VALVE IN OPEN POSITION WITH A FORCE GREATER THAN THAT DEVELOPED BY SAID TUBE PRESSURE SURFACE, AND MEANS FOR DEVELOPING A FORCE ON SAID INLET VALVE ADDITIVE TO THE FORCE OF CYLINDER PRESSURE FLUID ACTING ON SAID TUBE PRESSURE SURFACE TO THEREBY INITIATE OPENING MOVEMENT OF SAID TUBE AND CLOSING MOVEMENT OF SAID INLET VALVE.