Abstract: In a pneumatic nailer using compressed air for driving nails, a work chamber contains a drive piston and is in communication with a storage chamber for effecting the return of the drive piston after it has driven a nail. A valve unit controls the supply of additional compressed air into the storage chamber. A switching element is arranged to react when a predetermined compressed air pressure is exceeded for controlling the flow of compressed air through the valve unit to the storage chamber. The switching element can be a pressure limiting valve. The combination of the switching element and valve unit avoids unnecessary compressed air losses in the higher pressure operating ranges.

Abstract: In a pneumatic nail driver, compressed air drives a working piston in the driving direction within a working cylinder. An inlet valve controls the flow of compressed air into the working cylinder. A sensing element mounted on the front end of the driver moves opposite to the driving direction when it is pressed against the receiving material for the nail. The sensing element pivots a shift lever which in turn moves a safety valve for controlling in one position the flow of compressed air to the control space associated with the inlet valve and in another position to connect the control space to the ambient atmosphere.

Abstract: A magazine for caseless propellant charges, such as used in a fastening element setting device, consists of an elongated strip-like member. Cut-outs are provided in the strip-like member and a caseless charge holder is secured in each cut-out by webs. A caseless charge and the holder are displaced out of a cut-out when a sufficient force is directed against the holder to separate the webs from the strip-like member.

Abstract: A fastening element setting device powered by an explosive gas mixture includes a housing forming a guide cylinder for a propulsion piston which drives the fastening element into a receiving material. The components of the gas mixture, one at a higher pressure than the other, are delivered through separate supply lines into an inlet duct and then to a combustion chamber. A control slide valve is located between the supply lines and the inlet duct and regulates flow, with the higher pressure component following the lower pressure component into the inlet duct and combustion chamber. A closure valve in the supply line of the lower pressure component blocks any inflow when the higher pressure component flows into the inlet duct.