Abstract: The invention relates to a pneumatic percussive tool for a paving breaker and/or a hammer drill comprising a drive piston which is displaceable both backwards and forwards by a crankshaft and arranged in a percussion piston which is displaceable both backwards and forwards. A hollow chamber is connected to a compensating chamber by an idling air channel and embodied between the drive piston and the percussion piston in order to receive a pneumatic spring. A valve is arranged in the idling air channel, the opening and closing position thereof depending on the rotational speed of the crankshaft. If the rotational speed of the crankshaft falls below a predetermined value, the valve opens the connection between the hollow chamber and the compensating chamber so that a pneumatic spring can no longer be to embodied in the hollow chamber and the pneumatic percussion tool is placed in a idling position.

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 pneumatic spring percussion mechanism comprising a driving piston moving back and forth in a housing of the percussion mechanism and a percussion piston, wherein a pneumatic spring is configured between the driving piston and the percussion piston. The movement of the driving piston can be transmitted to a percussion piston by means of said pneumatic spring. The driving piston can be driven by an electric linear motor and is connected to an aromatic of the linear motor, forming a single piece therewith. This arrangement makes it possible to eliminate the use of a conventional rotary motor and a crank mechanism to drive the driving piston.

Abstract: A traction device for an internal combustion engine includes a tensioning device having two lever arms of different lengths which are rigidly connected together and which are pivotally mounted for rotation about a rotation axis. Each of the lever arms supports on one end a tension pulley. The tensioning device is provided for positioning the tension pulleys on a pulling strand and a return strand by imposing an elastic force thereon.

Abstract: Disclosed is a drilling and/or striking hammer comprising a lubricating device provided with a lubricant reservoir and a supply lubricant contained therein. A dosage device is provided with a dosage opening connecting the supply of lubricant to a place to be lubricated. Said invention also comprises a pressure generating device by means of which the supply of lubricant can at least temporarily be subjected to an increased amount of pressure, whereby lubricant exists from the dosage opening, allowing targeted lubrication of the movable parts.

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: 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.

Abstract: A belt tensioning device for a continuous belt drive. The device includes a torsion spring assembly (20) with a longitudinal axis (A2) and with at least one torsion bar or torsion tube (32). The torsion spring assembly (20) can be clamped axially and in a rotationally fast way into a rack. A tensioning arm (19), at one end, is arranged at the torsion spring assembly (20) so as to be aligned approximately radially relative to the longitudinal axis (A2). A tensioning roller (15) is rotatably fixed at the other end of the tensioning arm (19). The axis of rotation (A1) of the tensioning roller (15) extends substantially parallel relative to the longitudinal axis (A2) of the torsion spring assembly (20), and the tensioning arm (19) can be resiliently supported relative to the rack so as to oscillate around the longitudinal axis (A2).

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: 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 (23; 30), a striking tool (9) which can be actuated by the electric motor (23; 30) and a housing (2) wherein the electric motor and the striking tool are received. A handle (8) is embodied in such a way on the housing (2) that a holding position is arranged in a projection of the striking axis (6) of the striking tool (9). A rotating axis (25) of a motor shaft (26) of an electric motor is parallel to the axis of the striking axis (6), the total length (LGES) of the hammer drill and/or striking hammer (1) being small in the longitudinal direction.

Abstract: The invention relates to a pneumatic percussive tool for a paving breaker and/or a hammer drill comprising a drive piston which is displaceable both backwards and forwards by a crankshaft and arranged in a percussion piston which is displaceable both backwards and forwards. A hollow chamber is connected to a compensating chamber by an idling air channel and embodied between the drive piston and the percussion piston in order to receive a pneumatic spring. A valve is arranged in the idling air channel, the opening and closing position thereof depending on the rotational speed of the crankshaft. If the rotational speed of the crankshaft falls below a predetermined value, the valve opens the connection between the hollow chamber and the compensating chamber so that a pneumatic spring can no longer be embodied in the hollow chamber and the pneumatic percussion tool is placed in an idling position.

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 of 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: A traction device for an internal combustion engine includes a tensioning device having two lever arms of different lengths which are rigidly connected together and which are pivotally mounted for rotation about a rotation axis. Each of the lever arms supports on one end a tension pulley. The tensioning device is provided for positioning the tension pulleys on a pulling strand and a return strand by imposing an elastic force thereon.

Abstract: A drive belt of an internal combustion engine has a first pulley mounted on a crankshaft of the internal combustion engine, and a second pulley mounted on a shaft of a starter generator of the internal combustion engine. A belt is looped about both pulleys. A tensioner includes two tensioning arms, each of which loading a belt run of the belt and operating either as load-carrying belt run or non-load carrying belt run. Both tensioning arms are disposed to pivot about a rotation axis, with tensioning rollers mounted onto the tensioning arms and spring-biased against the belt. The tensioning arm disposed respectively upon the load-carrying belt run is urged into a stop position by a force applied by the belt.

Abstract: The invention relates to a pneumatic percussive mechanism for a percussion drill and/or a drill hammer. The inventive mechanism comprises, housed in the housing of the percussive mechanism, an axially reciprocating percussion piston. A drive piston is axially reciprocated in a guide cylinder of said percussion piston. The guide cylinder is provided on its inner face with one or more air compensation pockets. At least one idle opening extends through the guide cylinder. In the percussive action, the idle opening does not communicate with the ambience while in the idle mode the idle opening can be displaced via an idle channel that leads to the ambience and thus connects a cavity that receives a pneumatic piston with the ambience by way of the idle opening. The air compensation pockets and the idle openings allow and optimization of the piston return behavior and of the idle operation of the percussive mechanism.

Abstract: A pneumatic percussion power tool has a percussion tool housing in which a drive piston and a percussion piston are movable in an axial direction. The motion of the drive piston, which is generated by a crank mechanism, is transmitted to the percussion piston through a pneumatic spring in a first chamber so that the percussion piston cyclically strikes a ram or a tool. The backward motion of the percussion piston rebounding from the ram is supported by increasing air pressure in a third chamber that is supplied with air by the drive piston through a second chamber and a communicating channel.

Abstract: A handle for a drill- and/or chisel hammer has a mount which can be fixed to the hammer. A radial grip is fixed to said mount, the grip axis of said radial grip crossing a tool axis which is defined by the position of a tool received by the hammer. A tangential grip is also fixed to the mount. Said tangential grip has a first grip section whose grip axis is tangential to the tool axis and a second grip section whose grip axis is tangential to the tool axis and essentially perpendicular to the grip axis of the first grip section.

Abstract: The invention relates to a guiding cart for a manually guided tool, for example an abrasive cut-off machine, which comprises a movable frame on which a first and a second locating recess for inserting the abrasive cut-off machine are provided. A locking device is assigned to the first recess by means of which forces can be applied to the abrasive cut-off machine in the direction of the first locating recess and the second locating recess. In this way the abrasive cut-off machine can be reliably and rapidly fixed to the guiding cart after it has been inserted into the locating recesses. The insertion of the abrasive cut-off machine is facilitated by inclined inserting elements situated in the locating recesses.