Power rivet gun

Claim 1

A POWER RIVET GUN COMPRISING A HOLLOW BODY IN THE FORM OF A TUBULAR HOUSING HAVING A LONGITUDINAL BORE THEREIN, A NOZZLE SECURED TO ONE END OF SAID BORE AND HAVING A RESTRICTED BORE AXIALLY ALIGNED THEREWITH, SAID RESTRICTED BORE BEING ADAPTED TO RECEIVE THE HEADLESS SHANK END OF A MANDREL HAVING AN ENLARGED HEAD AT ITS OPPOSITE END FOR ENGAGING THE HEADLESS END OF A HOLLOW RIVET SUPPORTED ON THE MANDREL, MEANS IN THE LONGITUDINAL BORE OF THE BODY FOR GRIPPING A MANDREL, SAID GRIPPING MEANS COMPRISING OPPOSED JAWS AND MEANS LONTIDUINALLY MOVABLE WITHIN SAID TUBULAR BODY TO ENGAGE SAID JAWS AND MOVE THEM LONGITUDINALLY WITHIN THE TUBULAR BODY, A FIRST FLUID PRESSURE CHAMBER SECURED TO THE OPPOSITE END OF SAID LONGITUDINAL BORE, FIRST PISTON MEANS IN SAID CHAMBER CONNECTED TO SAID GRIPPING MEANS TO OPERATE THE SAME, FURTHER COMPOSITE PISTON MEANS IN SAID CHAMBER TO ACTUATE SAID FIRST PISTON, SAID LONGITUDINALLY MOVABLE MEANS FOR ENGAGING THE GRIPPING JAWS INCLUDING AN ACTUATING ROD, SAID ACTUATING ROD BEING CONNECTED TO SAID FIRST PISTON, A FURTHER FLUID PRESSURE CHAMBER IN THE END OF THE ACTUATING ROD REMOTE FROM SAID NOZZLE, SAID FURTHER PISTON MEANS INCLUDING A SMALLER PISTON MOVABLE IN SAID FURTHER FLUID PRESSURE CHAMBER AND CONNECTED TO A LARGER PISTON MOVABLE IN SAID FIRST FLUID PRESSURE CHAMBER, AND MEANS FOR INTRODUCING FLUID UNDER PRESSURE TO SAID FIRST CHAMBER TO ACTUATE SAID FURTHER COMPOSITE PISTON MEANS TO THEREBY ACTUATE SAID FIRST PISTON, SAID GRIPPING MEANS BEING OPERATIVE UPON SUCCESSIVE ACUTATION OF BOTH OF SAID PISTON MEANS TO DRAW THE MANDREL INTO THE NOZZLE TO CAUSE THE HEAD ON THE MANDREL TO EXPAND THE WALLS OF A HOLLOW RIVET AND SEPARATE FROM THE HEADLESS END OF THE MANDREL.