Abstract: In an apparatus for driving fastening elements, such as bolts and nails, into receiving material, a first or driving piston is mounted in a first chamber through which it is axially displaceable. A pressure converter arrangement is connected to an inlet to the first chamber for supplying the compressed air required for displacing the first piston for driving in a fastening element. The pressure converter includes a storage chamber, a second chamber in communication with the storage chamber and a third chamber. A double headed piston has one head in the second chamber and the other head in the third chamber. The third chamber has a much greater transverse cross-sectional area than the second chamber. Compressed air supplied to the third chamber compresses air in the second chamber which is directed into the storage chamber. From the storage chamber, the compressed air is charged into the first chamber for driving the first piston forwardly for inserting the fastening element.

Abstract: In a setting device, a magazine is advanced through a guide channel to present fastening elements in the path of a driving member. The magazine is moved in a step-wise manner by a transport pawl, and the pawl, in turn, is reciprocated relative to the drive channel by an operating member. A linkage interconnecting the operating member and the transport pawl, includes a pin secured to the operating member extending into a triangularly shaped recess in the transport pawl. The pin pivots the transport pawl out of engagement with the magazine in the guide channel and moves the pawl rearwardly so that it can again engage the magazine and move it so that another fastening element is aligned with the driving member.