Piston return and buffer system

Claim 1

A POWER-ACTUATED TOOL COMPRISING HOLLOW BARREL MEANS, A PISTON MOUNTED WITHIN SAID BARREL MEANS FOR MOVEMENT BETWEEN A FIRST FIRING POSITION AND A SECOND DRIVEN POSITION, SAID PISTON HAVING A HEAD PORTION AND A REDUCED ELONGATED SHANK PORTION, FASTENER GUIDE MEANS ATTACHED TO SAID BARREL MEANS AT ONE END THEREOF, SAID FASTENER GUIDE MEANS HAVING A LONGITUDINAL BORE COMMUNICATING WITH THE INTERIOR OF SAID BARREL MEANS, AND PISTON RETURN AND BUFFER MEANS OPERABLY MOUNTED BETWEEN THE HEAD PORTION OF SAID PISTON AND SAID FASTENER GUIDE, SAID PISTON RETURN AND BUFFER MEANS COMPRISING A STACK OF HOLLOW, GENERALLY FRUSTO-CONICAL WASHER MEMBERS OF ELASTOMERIC MATERIAL DEFINING A BELLOWS-LIKE STRUCTURE WHEN SAID PISTON IS IN ITS FIRST POSITION, SAID WASHER MEMBERS BEING COLLAPSIBLE TO A CLOSED TUBULAR COLUMN WHEN SAID PISTON MOVES TO SAID SECOND POSITION, SAID WASHES BEING DISPOSED ABOUT THE SHANK PORTION OF SAID PISTON AND SAID STACK EXTENDING FROM THE HEAD PORTION OF SAID PISTON TO SAID FASTENER GUIDE, SAID MEANS OPERABLE TO RETURN SAID PISTON TO AND SAID FIRST PISTON, SAID MEANS ABSORBING RELATIVELY LITTLE ENERGY OF THE PISTON DURING MOVEMENT THEREOF FROM THE FIRST POSITION TO SAID SECOND POSITION, BUT BEING CAPABLE OF ABSORBING A RELATIVELY LARGE AMOUNT OF ENERGY OF SAID PISTON IN THE EVENT OF MOVEMENT THEREOF BEYOND SAID SECOND POSITION.