Abstract: In a method for providing in a hand-held power tool electric energy for an engine control unit before start of an internal combustion engine of the power tool that is to be started by a rope starter, a voltage source is provided that generates electric energy electro-dynamically or photovoltaically before starting the internal combustion engine. The thus generated electric energy is stored in a rechargeable energy storage device arranged within the power tool. The electric energy stored in the energy storage device is supplied to the engine control unit upon first rope starter pull for start of the internal combustion engine. The device for performing the method has an electro-dynamic or photovoltaic voltage source and an energy storage device electrically conductingly connected to the voltage source, wherein the energy storage device has an output that is electrically conductingly connected to the engine control unit.

Abstract: In a method for providing in a hand-held power tool electric energy for an engine control unit before start of an internal combustion engine of the power tool that is to be started by a rope starter, a voltage source is provided that generates electric energy electro-dynamically or photovoltaically before starting the internal combustion engine. The thus generated electric energy is stored in a rechargeable energy storage device arranged within the power tool. The electric energy stored in the energy storage device is supplied to the engine control unit upon first rope starter pull for start of the internal combustion engine. The device for performing the method has an electro-dynamic or photovoltaic voltage source and an energy storage device electrically conductingly connected to the voltage source, wherein the energy storage device has an output that is electrically conductingly connected to the engine control unit.

Abstract: A cutting filament for a manually-guided trimmer, and a method of producing such a filament. A polymeric material is filled with platelet-shaped particles. The filled polymeric material is extruded in the form of a filament blank. In the solidified state, the filament blank is spun in the direction of its longitudinal axis, accompanied by plastic deformation, in such a way that the embedded particles are oriented at least predominantly in the direction of the longitudinal axis.

Abstract: A power tool has a drive motor that drives a tool and an optical guiding device secured on the power tool in alignment relative to the work tool. The guiding device is arranged in a low-vibration arrangement on the power tool and is in particular secured on the power tool in a low-vibration area of the power tool. At least one section of the power tool vibrates in the form of a standing wave in at least one direction, wherein the low-vibration area where the guiding device is arranged is the area of a node of the standing wave.

Abstract: A protective shield (2) is provided for a free-cutting tool (1). The free-cutting tool has a cutterhead (4) rotatable about a rotational axis (3) and carries a cutting filament (5). For a rotating cutterhead (4), the cutting filament (5) rotates in a rotational direction (10), aligns itself approximately radially to the rotational axis (3) and defines a cutting circle (6) having a constructively pregiven nominal radius (R). The cutting radius (6) is at least partially covered by the protective shield (2). A cut-to-length knife (7) having a cutting edge (8) for cutting the cutting filament (5) to length is mounted on the protective shield (2) in the peripheral region thereof. The cut-to-length knife (7) is mounted on the protective shield (2) to be moveable back and forth between a cutting position (11) and a rest position (12).

Abstract: A portable handheld work apparatus includes: a vibration suppressor for suppressing translatory vibrations occurring during operation of the work apparatus. A drive motor drives the vibration suppressor which defines a rotational axis. The vibration suppressor includes a suppression mass mounted at a radius from the rotational axis for generating an imbalance and, as a consequence of the imbalance, the suppression mass generates an rpm-dependent translatory vibration. A spring applies a resilient biasing force to the suppression mass in opposition to an rpm-dependent centrifugal force applied to the suppression mass during the rotation. The suppression mass is mounted so as to be radially movable along a path under the action of these forces. The suppression mass defines first and second equilibrium positions along the path at first and second radii from the rotational axis corresponding to first and second rpms of the vibration suppressor.

Abstract: A cutting blade for a motor-driven implement is provided. The cutting blade has a main body having a central fastening opening and blade sections that extend approximately radially from the main body. The blade sections have edges that extend in a radial direction and form cutting edges. Each blade section is provided with at least one bead-like embossment having a longitudinal axis that extends at an angle of between 0 and 45° relative to a longitudinal direction of the blade section.

Abstract: A protective shield (2) is provided for a free-cutting tool (1). The free-cutting tool has a cutterhead (4) rotatable about a rotational axis (3) and carries a cutting filament (5). For a rotating cutterhead (4), the cutting filament (5) rotates in a rotational direction (10), aligns itself approximately radially to the rotational axis (3) and defines a cutting circle (6) having a constructively pregiven nominal radius (R). The cutting radius (6) is at least partially covered by the protective shield (2). A cut-to-length knife (7) having a cutting edge (8) for cutting the cutting filament (5) to length is mounted on the protective shield (2) in the peripheral region thereof. The cut-to-length knife (7) is mounted on the protective shield (2) to be moveable back and forth between a cutting position (11) and a rest position (12).

Abstract: A portable handheld work apparatus includes a drive motor (1) and a vibration suppressor (2) which is rotatably driven by the drive motor (1). The vibration suppressor (2) compensates or absorbs translatory vibrations. The vibration suppressor includes suppression masses (4, 5, 6) for generating a targeted imbalance. The suppression masses (4, 5, 6) are arranged at a radius to the rotational axis (3) of the vibration suppressor (2). At least one suppression mass (5, 6) is mounted so as to be changeable in its position in dependence upon rpm.

Abstract: A tool head for a motor-driven, manually guided implement for receiving a rotatable cutter tool is provided. The tool head comprises a housing in which is provided a tool shaft that is rotatably mounted via bearings. Secured on the tool shaft so as to turn with it is a tool carrying mechanism for the cutter tool. This tool carrying mechanism includes an engagement plate having an engagement surface, which is oriented perpendicular to the axis of the shaft, and a centering shoulder. The engagement plate and a centering element having the centering shoulder are embodied as separate components. The engagement plate is of light weight construction and is positively connected with the tool shaft. The centering element is made of a material, the hardness of which is adapted to the cutter tool.

Abstract: A tool head for a motor-driven, manually guided implement for receiving a rotatable cutter tool is provided. The tool head comprises a housing in which is provided a tool shaft that is rotatably mounted via bearings. Secured on the tool shaft so as to turn with it is a tool carrying mechanism for the cutter tool. This tool carrying mechanism includes an engagement plate having an engagement surface, which is oriented perpendicular to the axis of the shaft, and a centering shoulder. The engagement plate and a centering element having the centering shoulder are embodied as separate components. The engagement plate is of light weight construction and is positively connected with the tool shaft. The centering element is made of a material, the hardness of which is adapted to the cutter tool.

Abstract: A cutting blade for a motor-driven implement is provided. The cutting blade has a main body having a central fastening opening and blade sections that extend approximately radially from the main body. The blade sections have edges that extend in a radial direction and form cutting edges. Each blade section is provided with at least one bead-like embossment having a longitudinal axis that extends at an angle of between 0 and 45° relative to a longitudinal direction of the blade section.

Abstract: A guide bar for a saw chain of a motor chain saw has a single member steel plate having a center plane and a circumferential guide groove for guiding a saw chain extending in the center plane. The steel plate has a longitudinal extension and a height perpendicular to the longitudinal extension. The steel plate has a cutout extending over a portion of the longitudinal extension and over a portion of the height. A filling member, consisting of a casting material having a smaller density than the steel plate, is cast into the cutout. The cutout has a circumferential edge facing the filling member. The circumferential edge has undercuts uniformly distributed along the circumferential edge. The filling member has a shrinkage rate of at least 0.5% for engaging positive-lockingly the undercuts upon solidification of the casting material to thereby create a uniformly distributed pretension within the center plane of the guide bar in the unloaded state of the guide bar.

Abstract: A clamping device for axially clamping a disk-shaped tool member on a shaft of a working tool has a pressure member for force-lockingly clamping the tool member between a radial surface of the shaft and the pressure member. A ring mount for force-loading the clamping member is provided for clamping and releasing the tool. An engaging device acting between the shaft and the pressure member is provided for positive-lockingly engaging the shaft upon actuation of the ring mount in a clamping direction of the clamping device.

Abstract: The invention is directed to a fuel pump for an internal combustion engine such as a two-stroke engine in a portable handheld work apparatus such as a motor-driven chain saw or the like. A pump chamber is connected via a suction valve to a fuel feed and via a pressure valve to a pressure line. A pump membrane delimits the pump chamber and is driven by the fluctuating crankcase pressure of the engine which is present in the work chamber. Pump operation free of disturbances over a wide rpm range is attained with the suction valve to the pump chamber being configured essentially as a valve having the shape of a part circle, The pressure valve is disposed approximately at the center of the suction valve and delimits the pump chamber in the stroke direction of the pump membrane.

Abstract: The invention is directed to a fuel-injection arrangement for a two-stroke engine in a portable handheld work apparatus such as a motor-driven chain saw or the like. Fuel is drawn by suction from a fuel tank by a fuel-feed pump and is made available at the suction connection of an injection pump. The injection pump has a pressure connection which is connected to an injection line through which the engine is supplied with fuel. A rapid start of a two-stroke engine provided with this fuel-injection arrangement is achieved by providing a bypass line which conducts fuel and bypasses the injection pump. A switchable flow valve is mounted in the bypass line. The bypass line opens directly into the intake channel conducting combustion air to the engine so that even without the pump action of the injection pump, adequate fuel is made available to the engine for starting the same.

Abstract: A cutterhead for a string trimmer having a rotatable drive shaft is adapted to hold and meter a cutting filament during operational use thereof. The cutterhead includes a disc-like carrier fixedly connected to one end of the drive shaft to permit the carrier to rotate about a rotational axis. The carrier has a peripheral edge and a peripherally extending outer wall approximately perpendicular to the carrier along the peripheral edge. The outer wall defines a space for accommodating the cutting filament in the cutterhead and has a guide eyelet disposed therein to define a pass-through opening for guiding the filament from the space to the outside of the cutterhead where a segment of the filament extends radially outwardly from the outer wall to define a cutting plane when the drive shaft rotates. The guide eyelet is made of wear-resistant material and is adapted to the diameter of the cutting filament.

Abstract: The invention is directed to a fuel-injection arrangement for a two-stroke engine in a motor-driven chain saw. An injection pump is mounted in a base housing with the injection pump including a pump piston axially displaceable in a pump cylinder. The pump piston delimits a pump chamber. The pump chamber is connected via a suction valve to a fuel tank. The fuel drawn by suction is pumped by the pump piston via a pressure valve, an injection line and an injection valve to the engine. For driving the pump piston, the latter is connected at one end to a membrane via a membrane plate. The membrane delimits a work chamber charged with fluctuating crankcase pressure. A simple assembly is provided by arranging the pump chamber, the suction valve and the pressure valve in a common valve housing which, in turn, is seated in the base housing of the injection pump in a seal-tight manner. The injection line is connected directly to the valve housing.

Abstract: The invention is directed to a pump for pumping a viscous fluid. The pump includes a stator body and a rotor body rotatably mounted in the stator body so as to be coaxial therewith. The stator body has a wall structure having a spiral slot formed therein which communicates with a suction connection formed in the stator body for conducting the viscous fluid to be pumped into the slot. A pressure connection is formed in the stator body for conducting the viscous fluid out of the slot. The suction connection and the pressure connection open into respective peripheral annular slots which are formed between a total of at least three sealing rings on the outer surface of the stator body. The channels for liquids provided in a housing can be disposed in any rotational position relative to the stator. This affords the advantage that the pump stator can be seated with any rotational position in a receiving cylinder of the housing.

Abstract: The invention is directed to a guide bar for guiding the saw chain of a motor-driven chain saw. The guide bar of the invention has a lamellar configuration and is not made of three parts as are conventional guide bars. Instead, the guide bar of the invention is made of two side parts. The two side parts are connected by means of spacers which are configured as projections on at least one of the two side parts. The side parts can be frames having large inner openings and are preferably stiffened. The connected frames define a composite frame which can be filled with plastic. The spacers determine the spacing of the side parts and therefore the width of the guide groove for the saw chain. The invention is also directed to a method of making the guide bar.