Abstract: The invention relates to a demolition hammer and/or hammer drill comprising a percussion generating device having a percussion piston moving axially back and forth. In a main percussion mode, the percussion piston impinges upon a tool which can move along a limited axial path straight into a main percussion direction. In a free percussion mode, the percussion piston indirectly impinges upon a percussion changing device, and by means thereof upon the tool, in a free percussion direction opposite to the main percussion direction. The impact surface of a tool shaft and the impact surface of a free percussion ram are placed opposite an impact surface of the percussion piston in such a way that the free percussion ram is removed from the effective area of the percussion piston by a return spring in the main percussion position.

Abstract: A percussion hammer drill and/or percussion hammer that can be guided by a handgrip comprises a pneumatic spring striking mechanism with a reciprocating drive piston and with a percussion piston that can be operated by the drive piston. A cavity for accommodating a pneumatic spring is provided between the drive piston and the percussion piston. The cavity can be connected to the surrounding area via a no-load operation channel in order to achieve a no-load operation. This this end, a valve is situated inside the no-load operation channel and can be controlled according to an application force that can be applied to the handgrip by the operator.

Abstract: The invention relates to a type plate for machines which serves as a support for written and/or graphical information. The inventive type plate is provided with a storage device which is integrated therein and which is suited for inputting and outputting data.

Abstract: A tamping machine for compacting soil has a crank mechanism for producing a directed vibration. The crank mechanism is coupled to a spring assembly. The parts of the crank mechanism which move back and forth linearly are made from a material with a density less than that of steel. This construction prevents vibrations which are unpleasant for the person operating the working machine from occurring.

Abstract: According to the invention, a hammer or a ramming machine for compacting soil has a crank mechanism for producing a directed vibration. The crank mechanism is coupled to a spring assembly. The parts of the crank mechanism which move back and forth linearly are made from a material with a density less than that of steel. This construction prevents vibrations which are unpleasant for the person operating the working machine from occurring.

Abstract: The invention relates to a soil compacting device comprising a motion detection device for detecting an actual value for the travelling motion of the soil compacting device. Inside a travel control device, the actual value is compared with a set value that is predetermined by the operator. When a difference between these two values is determined, the travel control device corrects the travelling motion by controlling a steering device or a drive of the soil compacting device. In another embodiment of the invention, a number of vibration plates are connected by the means of connecting elements to form a soil compacting system, which is also provided with a travel control device. The travel control device controls the individual drives in order to steer the entire soil compacting system.

Abstract: The invention relates to a handheld hammer drill and/or paving breaker which is at least of average weight and power class and which comprises an electric motor, a striking tool which can be actuated by the electric motor and a housing wherein the electric motor and the striking tool are received. A handle is embodied in such a way on the housing that a holding position is arranged in a projection of the striking axis of the striking tool. A rotating axis of a motor shaft of an electric motor is parallel to the axis of the striking axis, the total length of the hammer drill and/or striking hammer being small in the longitudinal direction.

Abstract: A pneumatic percussive tool for a paving breaker and/or a hammer drill, provided with a drive piston which is axially displaceable both backwards and forwards, comprising a guide sleeve and a piston bottom supporting the guide sleeve. A percussion piston can be displaced axially in the guide sleeve of the drive piston with the piston head thereof in percussive mode. During the transition from percussive to idling mode, the piston head slides out of the guide sleeve in such a way that the percussion piston is substantially maintained in the idling mode in an axially displaceable manner by means a stationary part of the percussion tool housing as opposed to being so maintained in the guide sleeve. The axial length of the drive piston can be reduced, whereby the mass of the drive piston and vibrations caused by the movement of the drive piston in the percussive and idling mode can also be reduced.

Abstract: The invention relates to an internal vibration device having an electrical motor mounted in a vibrating unit housing and having a rotating device comprising an out of-balance mass that is also mounted in the vibrating unit housing. The invention is characterized in that eccentricity of a center of gravity of the out-of-balance mass can be varied relative to the axis of rotation of said out-of-balance mass depending on the direction of rotation of the electrical motor. Said internal vibration device is suitable both for compacting unset concrete and for distributing concrete in the formwork.

Abstract: A device for compacting the soil comprising a soil contact element which is impinged upon by an oscillation exciter enabling the soil to be compacted. The soil contact element is elastically coupled to an upper mass. The upper mass is used as a detection mass, whereby the acceleration thereof is detected by an acceleration sensor. A measuring signal emitted by the acceleration sensor is evaluated in a control device which controls the oscillation exciter according to a deviation from a set value.

Abstract: The invention relates to an operating device which is provided for operating an appliance and which comprises a hand-actuated operating part on which at least one light detector is provided in the gripping area of the hand. The light detector and an evaluating circuit make it possible to detect when a hand is approaching the guide handle or when the hand is gripping the same. The evaluating circuit accordingly activates a control device which optionally places the appliance in operation.

Abstract: A hammer or a ramming machine for compacting soil has a crank mechanism for producing a directed vibration. The crank mechanism is coupled to a spring assembly. The parts of the crank mechanism which move back and forth linearly are made from a material with a density less than that of steel. This construction prevents vibrations which are unpleasant for the person operating the working machine from occurring.

Abstract: A tool consists of a combination engine in the form of a two-cycle engine, and a motion conversion device which is connected to said combustion engine and which is located in a housing. The housing is filled with oil for lubricating the motion conversion device. A conveying device with which the oil is conveyed from the housing to the combustion engine is provided, said combustion engine being lubricated exclusively with oil from the housing and having no separate oil supply.

Abstract: The invention relates to a protective device for an electric consumer. A residual-current circuit-breaker is located in an electrical supply line between a mains connection and a switch device of the consumer. Said residual-current circuit-breaker has a detection device for recognizing a residual current and a first interrupter for interrupting the supply of electricity from the mains connection to the switch device in accordance with a switching signal from a detection device. If an electrical energy storage device is provided in the switching device, a second interrupter is provided, this second interrupter being controlled by the residual-current circuit-breaker.

Abstract: The invention relates to a poker vibrator for compressing concrete. The poker vibrator comprises a vibrating housing that accommodates an unbalanced mass and an electromotor, an insulating plastic tube that links the vibrating housing to a switch cover, an electric cable that links the switch cover to a connector shell and that bears a power plug, and a frequency converter that supplies the current for the electromotor. The poker vibrator is characterized in that the switch is arranged separately from a coupling piece on the tube and not on the electric cable and/or in that at least some of the components of the frequency transformer are arranged in a transformer housing provided between the switch housing and the powerplug.

Abstract: The invention relates to a soil compacting device comprising a vibration generator that acts upon a soil contact plate. A controlling means of the vibration generator comprises an amplitude-controlling unit and a frequency-controlling unit. The amplitude-controlling unit diminishes the vibration amplitude by a first amplitude difference when a jumping of the soil contact plate is detected. When no jumping is detected within a clock timing, the amplitude-controlling unit increases the vibration amplitude by a second amplitude difference. The frequency-controlling unit determines the driving power that is output by a drive to the vibration generator and changes the vibration frequency so that the driving power approximately corresponds to a preset value. The amplitude control and the frequency control are advantageously carried out in parallel.

Abstract: A roller device for compacting the ground comprising a rotatably driven first roller facing, whose speed can be modified, at least within a certain range. Device includes a unit for determining the vertical distance between a surface of a compacted ground lying behind the first roller facing and a lowest point of the first roller facing, and by a speed regulating device for modifying the speed of the first roller facing, based on said distance. The speed regulation device allows the speed of the roller facing to be adjusted in such a away that slip is prevented without determining the actual slip between the roller facing and the ground.

Abstract: A vibration exciter for a ground compacting devices such as a vibratory plate comprises unbalanced shafts which are arranged parallel or coaxial to one another, which can be driven in counter-rotation with the same rotational speed, and which each carry at least one centrifugal weight, whereby the phase position of the centrifugal weights can be adjusted by a phase adjusting device in such a manner that the vertical components of the centrifugal forces generated by the centrifugal weights are cancelled out in each rotational position. At the same time, the horizontal components of the centrifugal forces are correspondingly added in the same direction. This phase position prevents the vibratory plate, when stationary, from introducing any vertical vibration into the ground to be compacted, but enables it to introduce shear stresses via a ground contact plate into the ground, preferably an asphalt surface, in order to compact cracks and pores.

Abstract: The invention relates to a motor-driven operating device that comprises a guide handle. Two sensor elements are provided on the guide handle and in two handle areas for detecting the hands of an operator. An ignition device of the motor is controlled by means of a security control device in such a way that the speed can only be increased beyond a security speed when the guide handle is held with both hands, whereby said security control device evaluates the sensor signals. The motor speed is limited to the security speed when the two sensor signals are missing.

Abstract: The invention relates to a cutting device that is provided with a traveling mechanism and a cutting disc that can be rotatably driven by a drive unit. The drive unit and the cutting disc are arranged on a support frame. An undercarriage is movably fixed to the support frame. A relative position can be adjusted between the undercarriage and the support frame by means of an adjustment device. The adjustment device is provided with a coarse adjustment device for adjusting at least two discrete relative positions and a fine adjustment device, which overlaps the effect of the coarse adjustment device in at least one of the discrete relative positions. The fine adjustment device is used for adjusting any relative position in a determined area.