Abstract: The invention relates to an intake arrangement (1) for the combustion air (2) of an internal combustion engine (3) in a handheld work apparatus (4) such as a cutoff machine, a motor-driven chain saw or the like. An air filter (5) is provided for the cleaning of the combustion air (2) drawn in via an opening (6) of a filter housing (7). To discharge dust (11) accumulated in the air filter (5) a carrier airflow (10) is provided in a flow channel (16) and the filter housing (7) is fluidly connected with the aid of a discharge tube (13) to the flow channel (16). For a dosed metering of dust (11) from the filter housing (7), a shutoff member (14) is provided and the shutoff member (14) clears or closes the fluid connection between the flow channel (16) and the filter housing (7).

Abstract: The invention relates to an intake arrangement (1) for the combustion air (2) of an internal combustion engine (3) of a handheld portable work apparatus (4), such as a cutoff machine, motor-driven chain saw or the like. An air filter (5) is provided for purifying the combustion air (2). Dust-laden combustion air is directed onto the air filter via openings (6) of a filter housing (7). The combustion air (2) is purified by the air filter (5) and is drawn by suction by the engine (3) via an intake pipe (25) of a carburetor (8). A carrier airflow (10) is provided in a flow channel (15) for continuously or intermittently transporting away dust (11) deposited on the air filter (5). The combustion air (2) and the carrier airflow (10) are spatially separated via a discharge tube (13). In this way, a minimization of the dust load of the air filter (5) is ensured on the one hand and a continuous transport away of the dust (11) from the air filter (5) is ensured on the other hand.

Abstract: The invention relates to an intake system (1) for the combustion air (2) of an internal combustion engine (3) in a portable handheld work apparatus (4). The intake system (19) includes a filter housing (5) having an air filter (6) for purifying the combustion air (2). The clean space (8) of the air filter (6) is fluidly connected to an outlet opening (10) of the filter housing (5). The outlet opening (10) communicates with a carburetor (7) of the engine (3). A centrifugal-force separator (13) is mounted forward of the air filter (6) for separating large amounts of dust in the inducted combustion air (2). The separator (13) is so positioned ahead of the filter housing (5) that a central core flow (14) of the separator has a lower particle density (15) and is supplied to the filter (6). A tangential flow (16) surrounds the central core flow (14) in the interior of the separator (13).

Abstract: The invention relates to an intake arrangement (1) for the combustion air (2) of an internal combustion engine (3) in a handheld work apparatus (4) such as a cutoff machine, a motor-driven chain saw or the like. An air filter (5) is provided for the cleaning of the combustion air (12) drawn in via an opening (6) of a filter housing (7). To discharge dust (11) accumulated in the air filter (5) a carrier airflow (10) is provided in a flow channel (16) and the filter housing (7) is fluidly connected with the aid of a discharge tube (13) to the flow channel (16). For a dosed metering of dust (11) from the filter housing (7), a shutoff member (14) is provided and the shutoff member (14) clears or closes the fluid connection between the flow channel (16) and the filter housing (7).

Abstract: The invention relates to an intake system (1) for the combustion air (2) of an internal combustion engine (3) in a portable handheld work apparatus (4). The intake system (19) includes a filter housing (5) having an air filter (6) for purifying the combustion air (2). The clean space (8) of the air filter (6) is fluidly connected to an outlet opening (10) of the filter housing (5). The outlet opening (10) communicates with a carburetor (7) of the engine (3). A centrifugal-force separator (13) is mounted forward of the air filter (5) for separating large amounts of dust in the inducted combustion air (2). The separator (13) is so positioned ahead of the filter housing (5) that a central core flow (14) of the separator has a lower particle density (15) and is supplied to the filter (6). A tangential flow (16) surrounds the central core flow (14) in the interior of the separator (13).

Abstract: The invention relates to an intake arrangement (1) for the combustion air (2) of an internal combustion engine (3) of a handheld portable work apparatus (4), such as a cutoff machine, motor-driven chain saw or the like. An air filter (5) is provided for purifying the combustion air (2). Dust-laden combustion air is directed onto the air filter via openings (6) of a filter housing (7). The combustion air (2) is purified by the air filter (5) and is drawn by suction by the engine (3) via an intake pipe (25) of a carburetor (8). A carrier airflow (10) is provided in a flow channel (15) for continuously or intermittently transporting away dust (11) deposited on the air filter (5). The combustion air (2) and the carrier airflow (10) are spatially separated via a discharge tube (13). In this way, a minimization of the dust load of the air filter (5) is ensured on the one hand and a continuous transport away of the dust (11) from the air filter (5) is ensured on the other hand.

Abstract: A two-stroke engine for a portable two-stroke engine in a portable handheld work apparatus includes a combustion chamber (3) formed in a cylinder (2). The combustion chamber (3) is delimited by the piston (5) which drives the crankshaft (7) via a connecting rod (6). The two-stroke engine includes several transfer channels (14), which, referred to a symmetry plane (49), lie on opposite sides (47, 48) with the plane partitioning approximately the outlet (10). The transfer channels (14) connect the crankcase (4) to the combustion chamber (3). A first end (20) of each transfer channel (14) opens via an entry window (12, 15) into the combustion chamber (3) and the second end (19) of each transfer channel opens to the crankcase (4). Each transfer channel (14) is connected, between its ends (19, 20), to an air channel (22a, 22b) via a membrane valve (21). Air is supplied by the air channel (22a, 22b) via an adjustable throttle (31, 32).

Abstract: The invention relates to a two-stroke engine for a portable handheld work apparatus such as a motor chain saw. The combustion chamber (3), which is configured in a cylinder (2), is delimited by a piston (5) which drives a crankshaft (7) rotatably journalled in a crankcase (4). The crankcase (4) is connected to the combustion chamber (3) via a transfer channel (14). A first end (20) of the transfer channel (14) opens into the combustion chamber (3) via an entry window (12, 15) lying in the cylinder wall (16); whereas, the second end (19) of this transfer channel (14) is open toward the crankcase (4). The transfer channel (14) is connected between its ends (19, 20) to an air channel (22a, 22b) via a check valve (21). The air channel (22a, 22b) supplies essentially fuel-free gas via a throttle (31) having an adjustable throttle element (33). A mixture-preparation device (8) is provided for the air/fuel mixture downstream of an air filter (42) in the flow direction of the combustion air.

Abstract: The invention relates to the assembly of a shaft bearing (16) in the end section (6) of a guide tube (5) of a brushcutter (1). The guide tube (5) accommodates a drive shaft. The bearing (16) is axially inserted into the end section (6) and is held so that it cannot separate therefrom. The outer diameter (DM) of the outer surface (18) of the bearing (16) is configured smaller than the inner diameter (DI) of the end section (6) in order to facilitate assembly and to ensure a force-tight inseparable seating of the bearing 16 in the end section. Several axial ribs (19, 20, 21) are distributed uniformly over the periphery of the outer surface (18). The radial elevation (H) of the axial ribs is slightly greater than approximately half the difference between the inner diameter (DI) of the end section (6) and the outer diameter (DM) of the surface (18) of the bearing (16).

Abstract: The invention relates to a two-stroke engine for a portable handheld work apparatus such as a motor chain saw. The combustion chamber (3), which is configured in a cylinder (2), is delimited by a piston (5) which drives a crankshaft (7) rotatably journalled in a crankcase (4). The crankcase (4) is connected to the combustion chamber (3) via a transfer channel (14). A first end (20) of the transfer channel (14) opens into the combustion chamber (3) via an entry window (12, 15) lying in the cylinder wall (16); whereas, the second end (19) of this transfer channel (14) is open toward the crankcase (4). The transfer channel (14) is connected between its ends (19, 20) to an air channel (22a, 22b) via a check valve (21). The air channel (22a, 22b) supplies essentially fuel-free gas via a throttle (31) having an adjustable throttle element (33). A mixture-preparation device (8) is provided for the air/fuel mixture downstream of an air filter (42) in the flow direction of the combustion air.

Abstract: The invention relates to a two-stroke engine in a portable handheld work apparatus such as a motor-driven chain saw or the like. A combustion chamber (3) is formed in the cylinder (2) of the two-stroke engine (1). The combustion chamber (3) is delimited by the piston (5). The piston (5) drives the crankshaft (7) via a connecting rod (6) and the crankshaft (7) is rotatably journalled in the crankcase (4). The two-stroke engine includes several transfer channels (14), which, referred to a symmetry plane (49), lie on opposite-lying sides (47, 48) with the plane partitioning approximately the outlet (10). The transfer channels (14) connect the crankcase (4) with the combustion chamber (3). A first end (20) of each transfer channel (14) opens via an entry window (12, 15) into the combustion chamber (3); whereas, the second end (19) of each transfer channel opens to the crankcase (4). Each transfer channel (14) is connected, between its ends (19, 20) to an air channel (22a, 22b) via a membrane valve (21).

Abstract: A clutch cup for a centrifugal clutch of a hand-held working tool, driven by an internal combustion engine, has a clutch drum and a hub coaxially fastened to the clutch drum. A bearing bushing is arranged in the hub and fastened to the hub by a frictional and positive-locking connection. A receiving member is coaxially fastened to the hub and receives the drive shaft for driving the tool.

Abstract: An exhaust gas muffler for an internal combustion engine, especially in a manually guided implement such as a power chain saw and the like, is provided. The muffler has a housing having an inlet opening and an outlet for engine exhaust gas. An essentially cylindrical spark killer screen is fixed in position at a wall opening of the muffler housing that forms the outlet. The spark killer screen projects into the interior of the muffler housing. Adjoining the spark killer screen on the outer side of the muffler housing as an extension of the cylindrical spark killer screen is an exhaust gas pipe. This pipe is provided with threads and serves as a fastening device with which the spark killer screen and the exhaust gas pipe, as a fire protector, are fixed in position in the wall opening of the muffler housing.

Abstract: The invention relates to a cutoff machine having an internal combustion engine arranged for driving a work tool. The engine is held in a housing including a supporting component. Located in the housing is a fuel tank, from which the internal combustion engine is supplied with fuel. The fuel tank itself is connected via a venting tube to an equalizing vessel, which communicates with the atmosphere via a valve system. In order to connect the fuel tank to the equalizing vessel in an easily produced and assembled manner and in order to ensure safe venting of the fuel tank, a hollow body is provided in the supporting component. The hollow body is partitioned by a partition wall into two chambers, the one chamber forming the fuel tank and the other chamber forming the equalizing vessel. Both chambers are connected to each other via a one-piece venting component in which a venting line is formed.

Abstract: A hand-operated tool has a casing containing a motor for driving a tool member of the tool and a metallic tubular grip with a tube wall connected to the casing. The tube wall of the tubular grip has a profiled outer mantle surface made by deforming the tube wall. The profiled outer mantle surface has raised sections and indentations extending in the longitudinal direction of the tubular grip.

Abstract: A suction air filter for an internal combustion engine of a hand-held working tool has a housing having an inlet opening for air sucked in and an outlet opening for the clean air exiting the suction air filter and supplied as combustion air to a suction channel of the internal combustion engine. The housing includes a plurality of filter chambers arranged in series one after another in a direction of air flow from the inlet opening to the outlet opening. Each one of the filter chambers has at least one filter body positioned therein through which filter body the air flows.

Abstract: A cooling air blower for a combustion engine for a two-stroke engine of a hand-held working tool has a cooling air channel for supplying cooling air to a combustion engine and a blower fan for conveying air into the cooling air channel. A combustion air channel branches off the cooling air channel for guiding combustion air to an intake member of the combustion engine. The combustion air channel has a section extending adjacent to the cooling air channel. The combustion air channel has furthermore an air intake socket within that section, the air intake socket being narrower than the cooling air channel and extending transverse, when viewed in a plan view, to a main air flow direction of the cooling air channel into the cooling air channel. The air intake socket is positioned at a slant relative to the main air flow direction and has an inlet opening located on a side of the intake socket facing away from the blower fan.

Abstract: The invention is directed to a cooling-air blower for an internal combustion engine including a two-stroke engine of a portable handheld work apparatus. Cooling air is guided by a cooling-air channel to an internal combustion engine and a combustion-air channel conducts air to the intake pipe of the engine. A portion of the cooling-air flow is tapped at the pressure end of the blower. A segment of the combustion-air channel is disposed next to the cooling-air channel. A profile hollow body having a streamlined configuration extends from this segment of the combustion-air channel into the cooling-air channel. The profile hollow body is aligned at its location in the cooling-air channel with the flow direction of the cooling-air flow and has a rear end facing away from this flow. An inlet opening is provided in this rear end of the hollow body for receiving a portion of the cooling-air flow which is then passed to the combustion-air channel through the hollow body.