Abstract: An automatic screw driving gun has a belt feeder mechanism (1) for advancing a screw supply belt (2) through a feeder housing (6) in response to the rotation of a screw drive shaft or blade (11, 28) . The belt feeder mechanism (1) has a feeder lever (12) coupled to the rotating screw drive blade (11, 28) through a coupling device including a rocker lever (16) and a toggle lever (18) for a stepwise advance of the belt (4) through the feeder housing perpendicularly to the screw drive shaft. A cam driven by the screw drive shaft advances the feeder lever with each blade rotation whereby the power of the drive motor is used for the belt advance thereby relieving the operator.

Abstract: A handheld screw driving gun (1) has a handle (17) extending essentially perpendicularly relative to the motor axis (3--3) and a screwing axis (6--6) which is off-set below the motor axis. The handle is connected approximately at the center of gravity of the screw gun (1). A screwing bit (5) is also off-set from the motor axis (3--3) and is rotatably supported in a guide head (7) between the motor axis (3--3) and the handle (17). In this arrangement, the index finger of an operator's hand on the handle approximately aligns with the axis of the screwing bit (5) so as to assure a screwing direction perpendicularly to a work surface without applying any tilting forces to a screw. The arrangement of the drive motor behind the handle and the screwing unit in front of the handle provides a balance that reduces fatigue while holding and operating the screw gun with one hand.

Abstract: A pot shaped housing insert (6) is arranged in a driving apparatus for fastener elements, such as nails, between a pot shaped main body (2) and the driving cylinder (12). In such a driving apparatus the excess driving energy is taken up by an impact buffer (11) made of elastic material. The housing insert (6) is made of a synthetic material having a high inner damping, so that the excess driving energy and thus the impact noise are dissipated to a large extent already in the housing insert (6). Thus, the operator is not exposed to any unnecessary nuisance and the housing (1) may be manufactured more easily in an economical manner at lesser expense.

Abstract: The present buffer system for a fastener driving device includes two cooperating buffer elements (16, 22) located at the bottom (17) of the driving cylinder (2). A first buffer element (16) of hard elastic material rests on the inwardly facing surface of the cylinder bottom (17) in such a manner that at least a portion of the surface (18) of the first buffer element (16) contacting the bottom (17) is movable relative to the bottom (17) of the driving cylinder (2). A second buffer element (22) made of an elastic material softer than the hard elastic material of the first buffer element, rests on the first buffer element.

Abstract: A magazine for fasteners with heads is made of two separate, profiled, extruded channel members of light metal or thermosetting material. The channel members are held together by a plurality of screws or releasable clips. The channel members are further spaced from each other by an exchangeable spacer rod, whereby the magazine may be adapted to fasteners of different sizes by replacing the spacer rod with another spacer rod having a different thickness and height or width. Gliding shoulders, for example of spring steel wire, for the fastener heads are arranged longitudinally on the inwardly facing side of each channel member.