Robert Boschgmbh

Gunter Schaal

Gunther Berger

Dieter Dorr

Fred Weinmann

Fritz Schadlich

Manfred Kirn

Heribert Schramm

Werner Rieker

Karl-Heinz Braunbach

Wolfgang Jundt

Helmut Schneider

Friedrich Hornung

Eduard Gansel

Steffen Wunsch

Walter Barth

Arnim Fiebig

Werner Neubert

Erich Borst

Gerd Berner

Gerhard Armbruster

Hans-Joachim Vogt

Martin Kummer

Klaus Klingenstein

Kurt Metzger

Gunter Zilly

Karl Treyz

Dieter Schafer

Eberhard Seidel

Karl-Ernst Kober

Volker Lasch

Uwe Krieg

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. Since the other side of that intermediate disk does not have a toothed or friction rim, when the intermediate disk is installed in the other, turned-over position in operation a fine grinding motion results without a rotary motion around the eccentric shaft.

Eccentric grinding machine

Clamping device for axially clamping of a tool, especially a disc

Hand power tool with a multi-part, manually operable quick-action chuck

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. The magnetization current supply can be through a capacitor, resistor, or resistor-capacitor combination, which can be permanently connected across the power supply (10, 11) of the motor, or connected in circuit only when the switch (S, S.sub.2) changes the motor into dynamic braking operation.

Electrical series motor with dynamic braking circuit

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.

Eccentric grinder with a device for changing a grinding motion

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.

Hand tool for clockwise and counterclockwise rotations

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.

Bench

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. Timing duration of at least one of the timing circuits can be controlled as a function of motor temperature to provide for linear response of the system, regardless of changes of motor operating parameter versus torque characteristics under varying motor temperature conditions.

Automatic screwdriver or torquing tool control system

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).

Workbench with removable vise

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.

Cutting roller

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.

Low noise planing machine, particularly hand planer

Growing community of inventors

Stuttgart, Germany

Gunter Schaal