Abstract: A two-stroke engine (1) has a combustion chamber (3) configured in a cylinder (2). The combustion chamber (3) is delimited by a reciprocating piston (5) and drives a crankshaft (7) which is rotatably journalled in a crankcase (4). The two-stroke engine (1) has an outlet (10) out of the combustion chamber (3) and at least one transfer channel (12, 15) which connects the crankcase (4) to the combustion chamber (3) at pregiven piston positions. The transfer channels (12, 15) open with transfer windows (13, 16) into the combustion chamber (3). To obtain a good start and good idle performance and low exhaust-gas values, an ancillary channel (14) is provided which is connected into the combustion chamber (3) at one end (37) and into the transfer channel (15) with the other end (36). During operation, the ancillary channel (14) opens into the combustion chamber (3) during the downward stroke of the piston (5) while the transfer window (16) to the combustion chamber (3) is still closed.

Abstract: A two-stroke engine (1) is especially for a handheld work apparatus such as a motor-driven chain saw, a cutoff machine or the like and has a cylinder (2) wherein a combustion chamber (3) is formed. The combustion chamber (3) is delimited by a reciprocating piston (5). The piston (5) drives a crankshaft (7) via a connecting rod (6). The crankshaft (7) is rotatably journalled in the crankcase (4). The combustion chamber (3) is connected to the crankcase (4) at pregiven piston positions via at least one transfer channel (11). The combustion chamber (3) has an outlet (10) for exhaust gases. An air channel (9) is provided which conducts combustion air into the crankcase (4) and a throttle element is mounted in the air channel (9). A compact configuration of the two-stroke engine (1) can be achieved when a separate fuel inlet (13) is provided in the crankcase (4) which is fed by a fuel metering system (15).

Abstract: A blower (1) having a housing (10) to which a blower pipe (2) may be removably connected. An internal combustion engine located within the housing (10) drives a blower wheel. The blower wheel, in turn, generates an air flow (11) within the blower pipe. To reduce the exhaust gases and the fuel consumption during idle operation of the combustion engine, a reduction device (12, 22), located in the blower pipe downstream of the blower wheel, reduces the clear cross section of flow during idle operation of the engine.

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 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 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).