Abstract: The eccentric grinder includes a housing, a fan wheel mounted rotatably in the housing and being rotatably driven in the housing during operation, an eccentric shaft mounted rotatably and eccentrically in the fan wheel, a grinding disk nonrotatably fixed in a central portion thereof with the eccentric shaft and an outer region of the grinding disk being arranged without connection to a remaining group of parts of the grinder and axially spaced therefrom; and at least one exchangeable reversible intermediate plate. Each of the intermediate plates can be mounted nonrotatably on the eccentric shaft between the grinding disk and the housing during operation in one of two positions. To cause a rotary motion of the grinding disk in addition to an eccentric motion one of the intermediate plates is provided with only one toothed or friction rim which is engaged in a fixed toothed or friction rim provided on the housing when the intermediate plate is installed in one of the two positions during operation.

Abstract: A device for axially clamping a disc-shaped tool on a flange of a driven spindle with a threaded end, includes a clamping nut, a clamping disc supported on the clamping nut for biasing the disc against the flange and connected with the clamping nut for joint rotation therewith and axial displacement relative thereto, and supporting bodies arranged between the clamping nut and the clamping disc. An actuating member is located between the clamping nut and the clamping disc, and rolling bodies are displaceable along guide paths defined by guide tracks of the supporting bodies and guide track means of the actuating member for radially loading the supporting bodies. An insert member is supported between the clamping nut and the clamping disc and includes a plurality of stops projecting into the guide paths.

Abstract: The eccentric grinder includes a housing, a griding disk on which a grinding paper is held, an eccentric shaft on which the grinding disk is nonrotatably mounted and a mechanism for changing a grinding movement of the grinding disk having at least one fixed friction or toothed rim. At least one exchangable reversible intermediate plate (17,37) is provided for the grinder attachable to the eccentric shaft and each having at least one other friction or toothed rim (21,22). In operation, one of the intermediate plates (17,37) is placed between the housing (6) and the grinding disk (24), which, when engaging the fixed friction or toothed rim (34,35) with one of its friction or toothed rims (21,22), causes a rotary motion of the grinding disk (24) in addition to an eccentric motion.

Abstract: For a hand power tool (1) with a multi-part manually operable quick-action chuck (2) for a disc-shaped tool (3) which is held on a shoulder (4) of a drive spindle (5) and onto which a force can be loaded from the other side by a pressure plate (7), with the pressure plate (7) concentrically embracing a threaded part (13) and being arranged positionally secured in relation to the threaded part and rotatable, with a hand screw part (11) embracing the threaded part (13) and th pressure plate (7) like a sleeve, and forming an annulus (14) with these, which contains at least a rolling contact bearing (9) and a drive which couples together the hand screw part (11), the threaded part (13), and the pressure plate (7), for improved function and a simplified design, and for a limitation of the maximum clamping pressure on the tool, a rolling planetary drive is formed from at least one of the rolling contact bearings (9, 12) in conjunction with a springly element (10), the drive which couples the pressure plate (7), the

Abstract: To provide sufficient magnetization to the field of a series motor when the series motor is to be operated in dynamic braking mode, with a dissipating resistor or short circuit element (4) connected across the armature (5), a circuit connection is established between one of the main terminals of the motor through the series field to supply a minimum magnetization current, at least when the motor operates under dynamic braking conditions, typically a few to up to 15% of no-load current of the motor. This is sufficient magnetization so that, even in larger motors where remanent magnetism of the field structure is insufficient, reliable dynamic braking can be ensured. A switch (S; S.sub.1, S.sub.2) selectively connects the motor armature for motor drive or running operation and dynamic braking operation.

Abstract: An eccentric grinder includes a motor-driven shaft, an eccentric drive connected to the shaft to impart to a grinding disc one mode of grinding motion and a rolling drive including friction or toothed crowns on the grinding disc and the housing cooperating with each other to impart to the grinding disc another mode of grinding motion. The grinder is provided with a ring carrying two toothed crowns at the opposite edges thereof and releasably insertable into a recess formed in a ring-shaped element fixed to the housing of the grinder so that one mode of grinding can be easily changed to the other mode of grinding.

Abstract: A hand machine tool for clockwise and counterclockwise rotation includes a universal electric motor and a reversing switch. The reversing switch is comprised of a contact plate and a contact holder both provided with coupling elements for coupling the contact plate and the contact holder for limited relative rotation. The coupling elements of the contact plate and the contact holder enclose a dust-sealed chamber in which contacts are accommodated.

Abstract: A bench includes a rigid frame and a work board pivotable to and away from the frame. The work board can be brought into a rest position and into a plurality of operating positions and can be in at least two operating positions supported by an arm movably supported on the frame. The arm is pivotable with respect to the frame in a horizontal plane. The arm can carry at its free end a clamping device. The structure of the bench increases a range of clamping a work piece on the bench over the length of the work board.

Abstract: To permit reliable turn-OFF of the motor when the torque of the motor is sufficient to provide for reliable seating of a screw or nut being driven thereby, start conditions of the motor are sensed, either in form of low-current condition or high power factor; high-torque conditions are sensed by low power factor, or high-current, in dependence on the desired torque level which results, respectively, in a comparatively steep phase angle-torque or current level-torque curve. A switch control is energized to turn-OFF the motor current if the phase angles, or the motor current, respectively, are beyond predetermined levels. To prevent in-rush current, or high power factors from affecting the operation of the turn-OFF system, timing circuits are provided to disable the turn-OFF system when the motor is first turned-ON or if the phase angle difference, as determined by time-comparator networks, between current and voltage, is below a predetermined value.

Abstract: A workbench (1) has a removable vise (3) and a workplate (5) separate from the vise and provided with apertures (6) for clamping elements. A jaw assembly (15) having a fixed vise jaw (16) and likewise a jaw assembly (17) equipped with an adjustable jaw (18) can be screwed onto a vise base (14) so as to resist all twisting forces. The screw fastenings (28 to 30) are such that they can also serve to attach the jaw assemblies to the workplate (5), using the apertures (6) in the latter for that purpose. The vise as a whole can be mounted in a rotary seat (2) where its mandrel (13) can be clamped at different levels and rotary positions, with the further possibility of having the rotary position fixed in the lowest position of the vise in a manner suitable for maintaining parallelism with another rotary vise similarly mounted (not shown in figure).

Abstract: A cutting roller for a hand-operated planing tool includes an elongated primary member and two pressure members, symmetrically surrounding the primary member at two side faces thereof. A plurality of planing knives are clamped between the pressure members and the primary member. The cutting roller is provided with fit elements which are attached to the primary member and fit in the recesses formed in the pressure members. During the assembly the fit members are aligned with the bearings of the cutting roller in the housing of the planing tool and then are attached to the primary member. The planing knives thereby are always aligned in the correct position with respect to the primary member. The pressure members are secured to the primary member by bolts.

Abstract: To reduce operating noise, and particularly the impact of sound pressure waves on the internal structure of the planing machine, the edges defining separating walls against which sound waves may impinge are inclined with respect to the axis of rotation of the cutter (16) or a theoretical line (46) parallel thereto, thereby extending the time of impact of individual pressure waves emanating from the cutter of incremental surface areas of the respective edges (26, 48, 50; 42, 52, 54; 30) to simultaneously attenuate the impact of the pressure waves and the timing of the impact.