Abstract: A vibrating plate serving as a tamping device comprises an upper mass (1) equipped with a drive and comprises at least two lower masses (2a, 2b), which are coupled to the upper mass (1) while being able to oscillate relative to the upper mass (1). Each of the lower masses (2a; 2b) comprises a soil contacting plate (6) and at least one oscillator (7) assigned to this soil contacting plate (6). The oscillators (7) can be controlled differently so that, in addition to an advancing and compacting action, a turning moment can be executed about a vertical axis (Z).

Abstract: A percussive mechanism, which is provided in the form of an, e.g. pneumatic spring percussive mechanism, comprises an electrodynamic linear drive, a drive piston, which can be reciprocally moved inside a percussive mechanism housing by the linear drive, and a percussive piston. An additional hollow space is provided in front of and/or behind the drive piston and can be isolated at least in part from the surrounding area so that a pneumatic spring can be created in the additional hollow space. The pneumatic spring slows the drive piston at its returning points and facilitates a returning motion without loading the electrodynamic linear drive.

Abstract: A vibrating plate for compacting soil comprises an upper mass; a lower mass, which is elastically coupled to the upper mass and which has at least one soil contact plate, and; a vibration generator device that acts upon the soil contact plate. The vibration generator device comprises at least four unbalanced masses that can each be rotationally driven about a rotation axis, the rotation axis of at least two of the unbalanced masses being arranged at an angle to the rotation axes of the other unbalanced masses. One of the unbalanced masses depicts a reference unbalanced mass that does not require its own phase adjusting device. On the other hand, a separate phase adjusting device is assigned to each of the other unbalanced masses, enabling the phase position of these unbalanced masses to be individually adjusted with regard to the reference unbalanced mass.

Abstract: A vibrating plate comprises an upper mass with a drive, a lower mass with a soil contact plate (12), and a vibration generator device, which belongs to the lower mass and which acts upon the soil contact plate (12). The vibration generator device comprises at least two individual exciters (13) each having an unbalanced shaft (2). The individual exciters (13) can be individually controlled with regard to the rotational speed and/or phase position of the respectively assigned unbalanced shaft (2). A mechanical coupling of the unbalanced shafts (2) is thus unnecessary. The unbalanced shaft (2) of an individual exciter (3) can be rotationally driven by a hydraulic motor (4). The position of the unbalanced shaft (2) is determined in at least one position by a position indicator (7).

Abstract: A drilling and/or percussive hammer comprises a handle (10) and a hammer housing (1), which can move relative to the handle (10) and inside of which, among other things, a pneumatic spring percussive mechanism (4) is housed. The pneumatic spring of the pneumatic spring percussive mechanism (4) can be ventilated via a no-load operation duct (13, 15, 17, 26, 27) that is opened and closed by a valve (16, 17, 25). The valve (16, 17, 25) can be opened and closed according to a pressing force acting upon the handle (10). A delay device (18, 20, 21, 29, 30) controls the valve (16, 17, 25) during closing so that the valve reaches the position corresponding to the detected pressing force only with a time delay. This causes a smooth transition from the no-load operation to the percussive operation.

Abstract: A vibrating plate system comprises at least two vibrating plates are mechanically coupled to one another via a coupling device and a controlling transmitter for outputting control data to the vibrating plates. Each of the vibrating plates comprises a receiving device for receiving the control data, a drive mechanism for propelling the vibration plate forwardly and rearwardly, and a position determining device for determining the position of the relevant vibrating plate within the group. A rule memory is also provided in which control rules are stored. One control rule defines a correlation between a control measure for controlling the traveling mechanism according to the position of the vibrating plate and an item of control information given by the control data. In each vibrating plate, a single control device selects a suitable control rule according to the position of the vibrating plate and to the control measure.

Abstract: A soil compaction device has a vibrated contact element that makes contact with the soil during a contact phase and that is exposed to a contact force exerted by the soil and travels over a contact distance. A dynamic stiffness of the soil is formed from the gradient of the contact force and from the contact distance. Furthermore, a contact surface parameter to take account of the actual contact surface of the contact element with the soil is determined. The dynamic deformation modulus is then the product of the contact surface parameter and the dynamic stiffness. The method allows the determination of the dynamic deformation modulus, and hence of the soil stiffness, during the compaction operation.

Abstract: The invention relates to a hand-held working tool, having a first unit, powered by a vibration on operation and a second unit which may be displaced relative to the first unit. A vibration isolation device is arranged between the first and second unit, having an actuator, for generation of a control force. An operational force acting in the working direction (A) between the first and the second unit may be at least partly compensated by the control force. The actuator is pneumatically operated and comprises an air spring for vibration isolation. A working piston in an air spring percussion device on the working tool serves to supply compressed air for the air spring. Alternatively, the compressed air can be supplied by the oscillating relative movement between the first unit and the second unit.

Abstract: The invention relates to a frequency converter for an immersion vibrator, comprising a mobile converter housing, and a converter circuit disposed in said converter housing and adapted to convert an electrical supply voltage to a special voltage. The converter is further provided with a feed line that is mechanically linked with the converter housing and electrically connected to the converter circuit. At the end of said feed line facing away from the converter housing a plug part is disposed. The converter circuit feeds a connector with the special voltage, a plug part of the immersion vibrator being insertable into said connector.

Abstract: An internal combustion engine in a working device comprises an oil reservoir near a crankcase to hold oil. An oil measurement device is used to recognize the existence of oil in the oil reservoir and to produce a corresponding signal that is evaluated in an evaluation device to produce an oil level reading. The oil level reading is preferred to be produced only during the starting of the internal combustion engine or within a specific time period after starting the internal combustion engine. When the internal combustion engine has reached its operating RPM, no further oil level monitoring is performed.

Abstract: The invention relates to a soil compacting system which comprises a travelling and steerable soil compacting device and a control device. The control device is provided with an area definition device which allows a user to establish an area to be compacted and the area boundaries. A position detecting device detects the actual position of the soil compacting device. A traveler changes the direction of travel of the soil compacting device by presetting a standard value for a travelling movement of the soil compacting device in such manner that the soil compacting device does not travel past the respective area boundary but continues its travel within the area. A path planning device may be provided for fixing a presetting for a travel way which makes sure that the soil compacting device, when keeping to the preset travel way, travels at least once completely across the area to be compacted.

Abstract: A boring and/or percussion hammer comprises an electrodynamic linear drive and a pneumatically damped percussion mechanism which is provided with a drive piston driven by the linear drive during the reciprocating movement thereof, an impact piston and a pneumatic spring arranged between the drive and impact pistons. An air-supply device comprises a pumping element, which is linearly forth and back movable for generating airflow. The pumping element is connected to the drive piston in such a way that the movement thereof is transmitted to said pumping element, thereby the cooling air is transported by an air channel for cooling heat generated elements.

Abstract: The invention relates to a device for compressing concrete during the manufacture of concrete parts. Said device comprises a supporting structure, a formwork device which is maintained by the supporting structure and a vibration decoupling device which is arranged between the supporting structure and formwork device. The vibrations required to compress concrete are produced by a vibration device acting directly upon the formwork device. In order to reduce noise emission, the mass of the supporting structure is selected in such a way that the intrinsic frequency of a system consisting of the supporting structure and vibration decoupling device is lower than the excitation frequency of the vibration device. Preferably, the formwork device, vibration decoupling device, vibrators and all electrical feed lines and connections are premounted, forming a module which can then be mounted on the supporting structure.

Abstract: A safety coupling in a percussion hammer and/or drill hammer, comprising a basic sleeve, a driven toothed wheel that is rotatably mounted on the basic sleeve and can be driven by a drive unit, a closing ring which is fastened to the basic sleeve, and a locking ring located between the driven toothed wheel and the closing ring. Said locking ring is fixed in a torsion-proof manner relative to the closing ring while being movable relative to the closing ring in an axial direction, counter to the effect of a spring mechanism. The locking ring is axially displaced while the driven toothed wheel remains in the axial position thereof when a threshold torque is exceeded.

Abstract: A vibration plate with a top mass and a bottom mass has, in addition to a spring device, a stabilizing device with which the bottom mass can be guided during its movement relative to the top mass. The stabilizing device has a transverse stabilizer which prevents tilting between the top mass and the bottom mass. The stabilizing device may likewise be formed by one or more Panhard rods, which prevent a transverse displacement between the top mass and the bottom mass.

Abstract: The invention relates to a vibrating plate for ground compaction, said plate comprising a remote control device for controlling at least one forward or rear journey by the excitation of an oscillation device. The remote control device comprises an emitter unit, which can be displaced independently of the remaining vibrating plate and which can be detachably fixed to a draw bar. In a remote control mode, the emitter unit is held by the user and displaced independently of the vibration plate. In a draw bar mode, the emitter unit is placed on one end of the draw bar, so that the user can guide the vibrating plate by the pulling and pushing of robust control handles on the emitter unit. The latter can have at least one control handle, which can be used not only to input control commands for controlling the oscillation device, but can also be held by the user to manually guide the vibrating plate.

Abstract: The invention relates to a percussion hammer and/or a drill hammer comprising a hammer housing, a handle which is preferably embodied as a handle cover and which can be displaced in a working direction (A) in relation to the hammer housing and which surrounds at least one part of the hammer housing. The hammer also comprises a guiding device which is used to guide the handle cover in a linear manner in relation to the hammer housing. The hammer is characterized in that the guiding device comprises a rolling body device which is active between the hammer housing and the handle cover. The rolling body device ensures that the handle cover is guided in a stable manner, with respect to tilting, in relation to the hammer housing.

Abstract: The invention relates to an air-cooled frequency converter, especially for construction site equipment, such as internal and external vibrators which are operated at a higher frequency than the existing electricity supply, said frequency converter comprising a housing and preferably being connected to a separation transformer for producing a protective extra-low voltage. The housing is divided into a converter receiving element surrounding a plate chamber, and a housing section connected to the receiving element and used as a cooling region, inside which cooling air channels and a fan for conveying the cooling air through the cooling air channels are arranged. The configuration of the housing in the cooling region are created by annular profiled elements which are cross-cut as desired, surround each other in an interspaced manner, and are coaxially arranged in relation to each other.

Abstract: The invention relates to a frequency converter for an immersion vibrator, comprising a mobile converter housing, and a converter circuit disposed in said converter housing and adapted to convert an electrical supply voltage to a special voltage. The converter is further provided with a feed line that is mechanically linked with the converter housing and electrically connected to the converter circuit. At the end of said feed line facing away from the converter housing a plug part is disposed. The converter circuit feeds a connector with the special voltage, a plug part of the immersion vibrator being insertable into said connector. A method of operating the immersion vibrator is also disclosed.

Abstract: An air spring hammer device comprises a drive piston, moving axially back and forth, with a front face of hollow embodiment and a hammer piston moving in said hollow. A ventilation slot is embodied in a guide wall of the drive piston. The drive piston may be guided in a guide tube. The guide tube comprises several idle openings. A moving control element is arranged on the exterior of the guide tube, in which control openings, corresponding to the idle openings, are provided. In an idle operating mode, the control element is in an open position, via which the ventilation slot, the idle openings and the control openings can be brought into connection with the environment.