Abstract: An operating mechanism is provided and has an operating lever, an adjusting lever, and a valve element that is rotatably disposed in a channel, wherein the adjusting lever is connected with the valve element via a shaft. A coupling element is provided for interconnecting the positions of the operating lever and the adjusting lever. The distance of the pivot axis of the adjusting lever from a connection of the coupling element with the adjusting lever is variable as a function of the position of the adjusting lever.

Abstract: An intake device having an intake channel that includes an intake channel section is provided. A butterfly valve is pivotably mounted in the intake channel section. A dividing wall is disposed downstream of the butterfly valve and divides the intake channel section into an air duct and a mixture duct. The air duct has a flow cross-section that is greater than the flow cross-section of the mixture duct. A fuel jet opens into the mixture duct.

Abstract: A carburetor for an internal combustion engine includes an intake channel section (2) as well as a throttle element journalled in the intake channel section (2). The throttle element is adjustable between a full-load position (25) and an idle position (26). A pump (20, 30) is provided for additional fuel metering and this pump includes a pumping chamber (24, 34) and a pump piston (21, 31) guided in the pumping chamber (24, 34). The position of the pump piston (21, 31) is coupled to the position of the throttle element. To ensure an optimal supply of the internal combustion engine with fuel in each operating state, the pump piston (21, 31) is so coupled to the throttle element that fuel is pumped from the pumping chamber (24, 34) into the intake channel section (2) when there is a displacement of the throttle element from the full throttle position (25) into the idle position (26).

Abstract: A carburetor arrangement for an internal combustion engine in a manually guided implement, such as a power chainsaw, a cut-off machine, etc. is provided. A regulating chamber delimited by a regulating diaphragm is provided. Upon deflection of the diaphragm due to underpressure in the regulating chamber, the latter is connected with a fuel tank. Via at least one nozzle, the regulating chamber opens into an air channel that supplies fuel/air mixture to the engine. The carburetor arrangement includes a scavenging pump that is disposed in a return line from the regulating chamber to the fuel tank, and in which is formed a pump chamber. The scavenging pump serves to completely fill the regulating chamber with fuel before start-up of the engine. To prevent the fuel/air mixture from becoming too lean after start-up, especially upon opening of the choke valve, a supply line is provided from the pump chamber into the air channel and supplies additional fuel to the air channel during the run-up phase.

Abstract: A carburetor for an internal combustion engine includes an intake channel section (2) as well as a throttle element journalled in the intake channel section (2). The throttle element is adjustable between a full-load position (25) and an idle position (26). A pump (20, 30) is provided for additional fuel metering and this pump includes a pumping chamber (24, 34) and a pump piston (21, 31) guided in the pumping chamber (24, 34). The position of the pump piston (21, 31) is coupled to the position of the throttle element. To ensure an optimal supply of the internal combustion engine with fuel in each operating state, the pump piston (21, 31) is so coupled to the throttle element that fuel is pumped from the pumping chamber (24, 34) into the intake channel section (2) when there is a displacement of the throttle element from the full throttle position (25) into the idle position (26).

Abstract: A carburetor arrangement for an internal combustion engine in a manually guided implement, such as a power chainsaw, a cut-off machine, etc. is provided. A regulating chamber delimited by a regulating diaphragm is provided. Upon deflection of the diaphragm due to underpressure in the regulating chamber, the latter is connected with a fuel tank. Via at least one nozzle, the regulating chamber opens into an air channel that supplies fuel/air mixture to the engine. The carburetor arrangement includes a scavenging pump that is disposed in a return line from the regulating chamber to the fuel tank, and in which is formed a pump chamber. The scavenging pump serves to completely fill the regulating chamber with fuel before start-up of the engine. To prevent the fuel/air mixture from becoming too lean after start-up, especially upon opening of the choke valve, a supply line is provided from the pump chamber into the air channel and supplies additional fuel to the air channel during the run-up phase.

Abstract: An intake device having an intake channel that includes an intake channel section is provided. A butterfly valve is pivotably mounted in the intake channel section. A dividing wall is disposed downstream of the butterfly valve and divides the intake channel section into an air duct and a mixture duct. The air duct has a flow cross-section that is greater than the flow cross-section of the mixture duct. A fuel jet opens into the mixture duct.

Abstract: An operating mechanism is provided and has an operating lever, an adjusting lever, and a valve element that is rotatably disposed in a channel, wherein the adjusting lever is connected with the valve element via a shaft. A coupling element is provided for interconnecting the positions of the operating lever and the adjusting lever. The distance of the pivot axis of the adjusting lever from a connection of the coupling element with the adjusting lever is variable as a function of the position of the adjusting lever.

Abstract: A carburetor, especially for the internal combustion engine in a motor-driven implement, is provided. Formed in the carburetor is an intake channel that has at least one partition extending in the direction of the longitudinal axis of the intake channel. The partition divides the intake channel into at least one air channel and at least one mixture channel. At least one fuel nozzle opens into the mixture channel. Pivotably mounted in the intake channel is a butterfly valve. To obtain a favorable starting and acceleration condition, with reduced exhaust gas values in the full throttle range, the butterfly valve is provided with at least two sections that are moveable relative to one another.

Abstract: A carburetor arrangement is provided for an internal combustion engine of a manually guided implement, and includes a carburetor that is embodied in particular as a diaphragm carburetor. A butterfly valve is pivotably mounted in an air channel that is disposed in the carburetor and leads to the internal combustion engine. Also provided is an accelerator pump that includes a pump chamber and an accelerator piston that is guided in the pump chamber. The accelerator piston is coupled with the butterfly valve. The pump chamber can be connected with a fuel tank via a pump line. A first pressure-controlled check valve is provided in the pump line.

Abstract: A membrane carburetor for an internal combustion engine in a portable handheld work apparatus includes a control chamber (3) delimited by a membrane (2). The control chamber (3) is connected via a feed line (4) to a fuel tank (5). The feed line (4) is cleared via a valve body (6) when there is a deflection of the membrane (2) because of an underpressure in the control chamber (3). The control chamber (3) is connected to an air channel (10) via at least one fuel nozzle (7) and at least one ancillary chamber (9). The air channel (10) passes through the membrane carburetor (1) and leads to the internal combustion engine. A purge pump (11) is provided in a fuel line (12) connecting the control chamber (3) to the fuel tank (5). The fuel path between the control chamber (3) and the purge pump (11) is guided through at least one ancillary chamber (9).

Abstract: A carburetor for an internal combustion engine is provided and includes at least one adjusting screw disposed in a housing for regulating the fuel/air mixture. The adjusting screw is screwed into a bore of the carburetor housing. The adjusting screw is embodied as a cheese head screw, whereby one end of the screw is provided with two slots that are cross-shaped relative to one another and extend over the diameter of the cheese head screw.

Abstract: A carburetor arrangement is provided for an internal combustion engine of a manually guided implement, and includes a carburetor that is embodied in particular as a diaphragm carburetor. A butterfly valve is pivotably mounted in an air channel that is disposed in the carburetor and leads to the internal combustion engine. Also provided is an accelerator pump that includes a pump chamber and an accelerator piston that is guided in the pump chamber. The accelerator piston is coupled with the butterfly valve. The pump chamber can be connected with a fuel tank via a pump line. A first pressure-controlled check valve is provided in the pump line.

Abstract: A membrane carburetor for an internal combustion in a portable handheld work apparatus includes a control chamber (3) delimited by a membrane (2). The control chamber (3) is connected via a feed line (4) to a fuel tank (5). The feed line (4) is cleared via a valve body (6) when there is a deflection of the membrane (2) because of an underpressure in the control chamber (3). The control chamber (3) is connected to an air channel (10) via at least one fuel nozzle (7) and at least one ancillary chamber (9). The air channel (10) passes through the membrane carburetor (1) and leads to the internal combustion engine. A purge pump (11) is provided in a fuel line (12) connecting the control chamber (3) to the fuel tank (5). The fuel path between the control chamber (3) and the purge pump (11) is guided through at least one ancillary chamber (9).

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: A membrane carburetor (1) for an internal combustion engine includes a control chamber (2) delimited by a membrane. The control chamber (2) is connected via a feed line (8) to a fuel tank (9). The feed line (8) is cleared with the deflection of the membrane (3) because of underpressure in the control chamber (2). The control chamber (2) is connected via at least one intake opening (16, 17) with an air-intake channel (14) to the engine. As start-assist devices for the engine, a scavenging pump (10) and an injection pump (20) are provided. The scavenging pump (10) is provided in a return line (13) between the control chamber (2) and the fuel tank (9). The fuel can be pumped into the air-intake channel (14) with a displacement piston (21) of the injection pump (20). The displacement piston (21) is longitudinally guided in a cylinder (22) and delimits a pump chamber (24). The pump chamber (24) is connected via an injection line (30) to a feed (18) of the intake openings (16, 17).

Abstract: A carburetor for an internal combustion engine is provided and includes at least one adjusting screw disposed in a housing for regulating the fuel/air mixture. The adjusting screw is screwed into a bore of the carburetor housing. The adjusting screw is embodied as a cheese head screw, whereby one end of the screw is provided with two slots that are cross-shaped relative to one another and extend over the diameter of the cheese head screw.

Abstract: A diaphragm-type carburetor is provided for a two-cycle engine, in a manually guided implement, that operates with layered scavenging. Formed in the carburetor housing is an intake channel portion in which is disposed a butterfly valve that is pivotably held by a shaft. Opening into the intake channel portion are fuel-conveying channels supplied from a fuel-filled control chamber that is formed on a longitudinal side of the intake channel portion in the carburetor housing and is separated from a compensation chamber by a diaphragm. Air for combustion is additionally supplied to the engine via an air channel formed in a functional component of the carburetor fixed on the housing thereof on a longitudinal side of the intake channel portion. The air channel is disposed approximately parallel to the intake channel portion and is guided from that end face of the carburetor that faces an air filter to the connecting side of the carburetor that faces the internal combustion engine.

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: A carburetor for an internal combustion engine of a hand-held working tool has a housing and a suction channel with a venturi section arranged in the housing. The suction channel has an inlet and an outlet for allowing air flow therethrough. A throttle is connected in the suction channel so as to be pivotable. A control chamber is provided and a main fuel channel connects the suction channel and the control chamber. An idle fuel channel connects the suction channel and the control chamber. A bypass, having an air supply line and a fuel supply line, is provided for introducing an auxiliary fuel/air mixture during a starting operation of the internal combustion engine to a location of the suction channel downstream of the throttle in a direction of air flow.