Abstract: A chain for a work implement has lateral connecting members connected to central driving members via studs. The stud has two lateral portions spaced apart from one another by a collar. A driving member is mounted pivotably on the collar. At the collar the stud has a surface layer harder than the base material. For a high chain service life, the stud has a diffusion layer above a surface layer above the base material. To produce the stud, the stud is provided with a diffusion layer at least at the collar, and a surface region of the collar is hardened, such that a surface layer is formed between the diffusion layer and the base material of the stud. For a method for producing a driving member, the driving member is provided with a diffusion layer at least at a circumferential surface of a hole and the driving member is hardened.

Abstract: A hand-held work implement comprises a housing, at least one tool and a combustion engine for driving the tool. The combustion engine has a cylinder and has a piston which drives a crankshaft in rotation about an axis of rotation. The crankshaft drives a fan impeller. The work implement has a handle unit with a handle bar and has an engine unit, these being connected to one another via anti-vibration elements. The combustion engine has a transverse plane which encompasses the cylinder longitudinal axis and which runs parallel to the axis of rotation of the crankshaft. The transverse plane divides the work implement into a front region, in which a section of the tool that projects out of the housing is arranged, and a rear region. The fixing of the anti-vibration element to the cylinder is realized in the front region.

Abstract: A coil support with a coil of a trimmer line has a coil core with an outer wall surface and first and second axial ends. At the axial ends securing elements that project past the wall surface of the coil core are provided for positional fixation of the coil wound onto the coil core. A securing element provided at the first axial end is a support plate with a longitudinal center axis. The size of the support plate is provided in the direction of the longitudinal center axis with a greater extension than transverse to the longitudinal center axis such that the support plate in a first radial direction of the coil core is greater than in a second radial direction. The coil core is fixedly connected with the support plate and with the further securing elements that are provided on the second axial end.

Abstract: A work apparatus has a work tool and a combustion engine which drives the work tool. The combustion engine has a rotatably mounted crankshaft. The work apparatus has a start enrichment device for the combustion engine. The start enrichment device includes an operating mode selector to be actuated by the operator. The start enrichment device has an operating position and at least one start position. The work apparatus has a reset unit which resets the start enrichment device from the start position into the operating position when the rotational speed of the crankshaft exceeds a reset rotational speed.

Abstract: An internal combustion engine has a fuel system that has a fuel valve with a housing, wherein in the housing a fuel chamber is formed. A fuel pump pumps fuel from a fuel tank into the fuel chamber. A conveying pump provides forced conveyance of fuel into the fuel system. A feed line is connected to the fuel chamber of the fuel valve. The conveying pump is arranged in the feed line and supplies fuel to the fuel chamber. A relief line is connected to the fuel chamber of the fuel valve and a first valve is arranged in the relief line.

Abstract: A hand-held power tool has an internal combustion engine provided with a throttle trigger adjustable between an idle position and a full throttle position. The engine has an operating mode selector adjustable between an operating position and a start position. In an intake passage of the engine, a throttle element is arranged that is in a throttling position when the operating mode selector is in the start position. The throttle element is secured in the throttling position by a locking action. The locking action is released when the throttle trigger is moved from the idle position toward the full throttle position. A restoring element is coupled permanently to the position of the throttle trigger. The restoring element, when the throttle trigger is moved for releasing the locking action, acts on the operating mode selector and restores the operating mode selector from the start position into the operating position.

Abstract: A capacitor power supply unit converts a mains voltage (U) into a lower operating voltage (V1) for a controller and a supply voltage (V2) for an electrical small load. A series circuit including a mains capacitor and a zener diode is connected to the mains voltage (U) whereat the supply voltage (V2) for an electrical small load having a permissible operating voltage is tapped off. The capacitor power supply unit provides for the supply voltage (V2) to be greater than the permissible operating voltage of the electrical small load and for the small load to be connected to the supply voltage (V2) via a buck converter. Here, the buck converter is controlled as a current source having a variable operating frequency.

Abstract: An ignition circuit for a combustion engine has an ignition coil and a control unit for the coil. The coil and the control unit are included in a common component as an ignition module. The module is supplied with voltage by a generator driven by the engine. A spark plug and the coil form a power circuit which includes a line segment to a reference potential outside the module. A sensor detects data of the engine and the output of the sensor is supplied to the module. The sensor is supplied with voltage via a sensor circuit. The sensor circuit and the power circuit use the line segment as a common connection to the reference potential, so that for a defect of the line segment, a missing connection to the reference potential in the high voltage circuit is recognized via the change of the sensor output signals.

Abstract: A hand-held power tool is provided with a drive motor and a clutch connected to the drive motor. The drive motor drives a tool member through the clutch. The clutch has a clutch drum with a circumferential wall provided with an end face. A follower member engages a groove in the circumferential wall of the clutch drum and a driven element is connected to the follower member to be driven by the follower member. The groove extends from the end face of the circumferential wall into the circumferential wall and has a groove bottom and two groove sides positioned opposite each other. The circumferential wall has a protrusion located at the groove bottom. The protrusion has a protrusion thickness measured at the groove bottom that amounts to at least approximately 110% of a wall thickness of the circumferential wall measured at the two groove sides.

Abstract: An internal combustion engine has a supply channel supplying combustion air. A throttle element is arranged in the supply channel and the position of the throttle element is adjustable by an operator-controlled element. The engine has a starter device which has an operating position and a starting position. In the starting position, the starter device opens up a defined flow cross section in the supply channel. The starter device locks in the starting position. The locking is released by actuation of the operator-controlled element. To achieve good starting performance of the engine, the engine has an intermediate stop which, upon the first actuation of the operator-controlled element after the release of the locking, is active and prevents the throttle element from opening fully, and which, during the subsequent closing movement of the throttle element, is deactivated such that the throttle element can be opened fully.

Abstract: A handheld work apparatus has a housing with a guide bar affixed thereto. A saw chain is driven along the guide bar which defines a central plane. A drive element for the chain is in a sprocket wheel space delimited by a sprocket wheel cover. The cover has a longitudinal edge which delimits the space adjacent to a first side of the saw chain. The longitudinal edge has a length from an entry region to a discharge opening. Over at least 50% of this length, the longitudinal edge is at a distance (L) to the housing. The distance (L) corresponds to the chain width (a). The distance of the longitudinal edge of the cover increases at the discharge opening in the running direction of the first side. The largest distance (b) of the longitudinal edge to the central plane is at least 110% of the smallest distance (c).

Abstract: A work apparatus has a work tool and a combustion engine for driving the work tool and further includes a start enrichment device for the combustion engine. The start enrichment device has a start position and is actuated via an operating mode selector. The work apparatus has a braking arrangement which brakes the work tool in the actuated position and releases the work tool in the unactuated position, and also an actuating device for the braking arrangement. To ensure that the start position can only be engaged when the braking arrangement is actuated, the work apparatus has a blocking device which prevents engagement of the start position in a blocking position. The braking arrangement is coupled to the blocking device such that the blocking device is in the blocking position with the braking arrangement in the unactuated position.

Abstract: A cutting blade for a hand-guided trimmer with a drive motor has a disk-shaped base member with cutting teeth disposed about a circumference of the base member. The base member has a first face and a second face opposite the first face. The cutting teeth each have a tooth face edge, the tooth face edge leading in driving direction of the cutting blade and extending radially, and a tooth back edge extending in the circumferential direction. The tooth face edge and the tooth back edge of the cutting teeth are alternatingly ground on the first face or the second face in the circumferential direction and define together a common cutting tip that is leading in the drive direction. Several of the cutting tips of the cutting teeth that are sequentially arranged in the circumferential direction are positioned in a common plane.

Abstract: A handheld work apparatus has at least one tool which is driven by a combustion engine. A portion of an intake channel of the combustion engine is formed by an elastic connecting piece which has a first section and a second section between which an expansion fold is arranged. The expansion fold has a first side wall and a second side wall arranged downstream of the first side wall. A peripheral wall, which extends in the region of the largest outside diameter (a) of the expansion fold, is arranged in flow direction between the first side wall and the second side wall. The connecting piece has a stop for the expansion fold which prevents a segment of the first side wall adjoining the peripheral wall from bearing against the second side wall.

Abstract: The invention relates to an arrangement for identifying a switching position of a switch (on an internal combustion engine in a handheld work apparatus. An energy source for supplying power to an inductive electrical load is provided, it being possible to connect the load to the energy source in order to be switched on and off via a controller. The switch is arranged in a voltage branch which is connected in parallel with the inductive load and in which a zener diode is also connected. The zener diode is activated or inactivated via the switch as a function of the switching position of the switch. The amplitude of the switch-off voltage, which is induced when the inductive load is disconnected, is limited by the zener diode, so that it is possible to read from the magnitude of the amplitude whether the switch is closed or open.

Abstract: A work apparatus has a drive motor for driving a work tool and has a control unit for the drive motor. The operating device includes an actuating element actuated by a user. The actuating element is mounted in a movable manner in a housing and can be adjusted in an actuating direction between a zero position and a maximum position. An intermediate stop acts between the zero position and the maximum position. The position of the intermediate stop is settable via a setting element. After the intermediate stop has been reached, the actuating element can be actuated further as far as the maximum position. The operating force (F) for further actuating the actuating element increases when the intermediate stop is reached. Provision is made for the operating force (F) to drop again upon further actuation of the actuating element after the intermediate stop has been overcome.