Abstract: A braking device for an electrical tool and including an actuation member (1), a braking drum (4) secured on the shaft of the electrical tool for joint rotation therewith, and a braking member (5) secured on the actuation member for joint displacement therewith, the actuation member being linearly displaceable upon a biasing force of a return spring acting thereon for pressing the braking member against a circumferential surface of the braking drum for braking the shaft and thereby the working tool.

Abstract: A tensioning device with a tensioning lever (1) and a detachable tensioning nut (2) has a pivotal tensioning cam (6), mounted elastically in the tensioning lever (1). The tensioning lever (1) has a seat (3) with a noncircular inside surface (4) for receiving the tensioning nut (2), which is mounted axially displaceably therein. The tensioning nut has an outside surface shaped to correspond to the noncircular surface of the seat (3). The tensioning nut (2) can be fixed removably in the tensioning lever (1) by a recess, which is disposed in the tensioning nut and into which the tensioning cam (6) can be engaged.

Abstract: In a non-commutating-pole commutator motor, in particular as the drive of a power hand tool, a device for reversing the direction of rotation includes a switch (8) for reversing the direction of current in the rotor winding, and a brush apparatus (4) mounted immovably in the motor casing. The rotation of the plane defined by the commutating coils is chosen in such a manner that good commutation is assured in one of the two directions of rotation at full motor output. Furthermore, the switch (8) for reversing the direction of rotation yields the preferred direction of rotation in a first switch position and the opposite direction in a second switch position. In the switch position for the preferred direction, a smaller number of turns of the field winding (1, 2) in the electric circuit of the motor is effectively provided while, in the opposite direction of rotation of the motor, a larger number of turns is effectively provided.

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.