Abstract: The invention relates to a dental preparation instrument that includes a tool that rotates in an alternately reversible manner. The preparation instrument has a drive for the tool. The drive provides a continuous fully rotational motion, and a gearing is arranged before the tool. Said gearing converts the continuous fully rotational motion of the drive into an alternately reversing rotational motion, which is continuous as viewed over several reversals.

Abstract: The invention relates to a dental preparation instrument (1), comprising a tool (6) that rotates in an alternately reversible manner, wherein the preparation instrument (1) has a drive (2) for the tool (6). The drive (2) provides a continuous fully rotational motion (7), and a gearing (43) is arranged before the tool (6). Said gearing converts the continuous fully rotational motion (7) of the drive (2) into an alternately reversing rotational motion (8), which is continuous as viewed over several reversals.

Abstract: The invention relates to a tuning device for setting the tension of one or more strings on a stringed instrument, comprising a peg receiving portion (10), which has pairs of bores (14) for rotatably receiving tuning pegs (20), wherein the tuning pegs (20) in each case comprise a peg body with a spindle (26) for insertion into a pair of bores (12, 14) in the peg receiving portion (10) and for winding up the end portion of a string and a peg grip (22), connected to the spindle (26), for turning the spindle (26) about a common axis (a) of the peg grip (22) and the spindle (26). A gear mechanism (33) is provided outside the peg receiving portion (10), functionally between the peg grip (22) and the spindle (26), and passes on to the spindle (26) a turning movement of the peg grip (22) about the common axis (a) that is reduced in its magnitude, wherein the gear mechanism (33) is an eccentric gear mechanism.

Abstract: In a device for clamping a circular saw blade, the saw blade is firmly clamped between two flanged rings and thereby connected to these so as to form an exchangeable tool unit which is pushed onto the free end of a saw shaft for rotation with the saw shaft and slidable displacement. Compression springs or the like are arranged between the tool unit and a stop face at the free end of the saw shaft to act upon one of the flanged rings and move the tool unit a short distance away from the stop face. A rotatingly mounted thrust plate which can be pressed centrically against the other flanged ring causes the tool unit to firmly engage on the stop face of the saw shaft.

Abstract: A circular saw comprises a machine structure, a gearbox, a motor-driven circular saw blade rotationally mounted on the gearbox and a pivot shaft on which the gearbox is pivotably supported. The pivot shaft is firmly connected at one end to the machine structure and is mounted at the other end in two brackets which form an angle between them. Each of these brackets is adjustable by means of an eccentric bearing rotatably mounted on the machine structure in such a way as to allow adjustment of the pivot shaft and with it the circular saw blade in the direction of two coordinates.

Abstract: In a device for advancing several workpieces placed side by side, a slide comprises several thin plates arranged alongside of one another. These thin plates are positionable against the workpiece end remote from a stop and are movable back and forth over a predetermined compensation distance parallel to the direction of advance of the workpieces. The compensation distance is longer than the greatest difference in length between the workpieces. The thin plates are prestressed by an energy accumulator which exerts a force which is larger than the force required for the advance of the workpieces. A first switch is arranged on the slide to switch off the slide drive as soon as one of the thin plates is displaced beyond the compensation distance in the direction opposite to the direction of advance.

Abstract: A pneumatically operated stop for advanced workpiece comprises a pneumatic cylinder with a displaceable piston rod on which a stop is secured. A limit stop coacting with the extended piston rod defines the setpoint position of the stop. A precision limit switch for sensing the setpoint position of the stop generates a command signal when the stop moves away from its setpoint position. This signal controls a valve which is connected with the pneumatic cylinder. This valve connects the pneumatic cylinder in an unpressurized manner with the ambient atmosphere when the stop is occupying the setpoint position and no workpiece is resting against the stop. Once the stop has been displaced from its setpoint position by an advanced workpiece, pressure is applied to the cylinder by this valve in order to return the stop together with the workpiece to the setpoint position, and this pressure is maintained for a preselected amount of time by the valve.