Andreas Stihl Ag & Co.

Andreas Stihl Ag & Co. Kg

Firma Andreas Stihl Ag & Co.

Bernhard D&uuml;rr

Manfred Rabis

Harald Schliemann

J&ouml;rg Schlossarczyk

Werner Geyer

Helmut Zimmermann

Karl-Heinz Kl&ouml;pfer

Hans Nickel

Johannes Menzel

Axel Klimmek

Reinhard Friedrich

Gerhard Stoll

G&uuml;nter Wolf

Wolf Burger

Rebekka Helfen

Horst Otterbach

Gustav W&ouml;lpert

Gunter Stein

Gerd W&ouml;llhaf

Thomas Rieger

Ronald Hotz

Klaus Martin Uhl

Peter St&uuml;cke

A diaphragm carburetor is provided for an internal combustion engine that operates with scavenging air, especially a two-cycle engine in a manually-guided implement. The carburetor has an intake channel portion in which is disposed a butterfly valve that is rotatably held via a shaft and in the vicinity of which fuel-supplying channels open into the intake channel portion. The channels are supplied from a fuel-filled regulating chamber that is formed on a longitudinal side of the intake channel portion in the carburetor housing and is separated by a regulating diaphragm from a compensation chamber. The carburetor has at least one air channel that supplies additional combustion air and that has an air valve that is rotatably held via a shaft. The butterfly valve and the air valve can be brought from a closed position, in which the butterfly valve or the air valve only insignificantly influence the flow in the intake channel portion or in the air channel, into a closed position in which the intake channel portion or the air channel are substantially closed off in an airtight manner, and in an opening direction from the closed position into the opened position. The air valve is coupled to the butterfly valve via a coupling mechanism that compensates for axial and radial tolerances and includes a spring.

Diaphragm carburetor for an internal combustion engine that operates with scavenging air

A cam drive is provided for a valve control of a mixture-lubricated internal combustion engine that has a cylinder, and a cylinder head in which is disposed a poppet valve which is actuated by a pivotable rocker arm. Mounted in a cam chamber is a control cam that is driven by the crankshaft of the engine and on the cam path of which rests a drag lever that transfers the cam lift to the rocker arm. To achieve a reliable mixture lubrication, a flow guidance element is disposed in the annular chamber between the peripheral wall of the cam chamber and the maximum diameter of the path of a cam nose. The flow guidance element is provided with a flow edge that is disposed adjacent to the drag lever in the vicinity of the path diameter of the cam nose.

Lubrication mechanism for a cam drive

A portable handheld work apparatus such as a motor-driven chain saw includes a housing ( ) of a drive unit ( ). The following are mounted in the housing ( ): an internal combustion engine ( ), a carburetor ( ) for fuel metering and an air filter ( ) as well as a fuel tank ( ). The air filter ( ) is mounted ahead of the carburetor in the flow direction of the fresh air flow. A largest possible filter action is obtained with a compact configuration in that a housing ( ) of the air filter ( ) lies at least partially in a space between the carburetor ( ) and the fuel tank ( ).

Portable handheld work apparatus

A valve drive mechanism is provided for an internal combustion engine, especially a four-stroke engine in a power chain saw. The implement housing is spanned by a front handle, the tubular grip of which is adjacent to the cylinder head of the engine and extends from one longitudinal side of the implement to the other longitudinal side thereof. A rocker arm of a valve control is pivotably mounted on the cylinder head between the ends of the rocker arm, with the rocker arm being pivotable about a pivot axis disposed transverse to the rocker arm. Push rods of a control mechanism engage one end of the rocker arm to actuate a poppet valve, on the valve stem of which the other end of the rocker arm acts. To be able to guide the tubular grip close to the center of gravity of the implement, the longitudinal axis of the rocker arm is disposed approximately parallel to the adjacent portion of the tubular grip.

Valve drive mechanism for an internal combustion engine

A cam drive is provided for a valve-controlled mixture-lubricated internal combustion engine having a cylinder in which is formed a combustion chamber that is delimited by the cylinder wall, a piston and a cylinder head. Disposed in the cylinder head are poppet valves, the respective valve shafts of which are driven via a pivotable rocker arm from a valve control that includes a control cam on the surface of which rests a contact lever that transfers cam lift to one end of the rocker arm. To ensure good lubrication of the cam drive even at high speeds, the control cam is rotatably mounted in the vicinity of the cylinder wall, in which is formed a through-bore. The first open end of the through-bore is disposed in the cylinder bore at the level of the piston in its lower dead center position, while the second open end opens into the cam chamber in the vicinity of the control cam.

An exhaust gas muffler is provided for an internal combustion engine, especially for two-stroke engines of manually guided implements such as power chain saws, brush cutters or the like. The muffler has a housing that includes two shells. One of the shells is provided with at least one outlet opening for exhaust gas. A cover is provided that guides the exhaust gas, and the cover has at least one discharge opening for the discharge of exhaust gas to the surrounding air. An exhaust gas chamber is formed within the cover. A screen element is disposed in the vicinity of the at least one discharge opening such that the exhaust gas stream is guided through the screen element.

Exhaust gas muffler for internal combustion engines

The invention relates to an exhaust-gas muffler on an internal combustion engine in a motor chain saw. The exhaust-gas muffler includes a housing ( ) which is assembled of two housing shells ( ). The one housing shell ( ) has an exhaust-gas inlet ( ) and the other housing shell ( ) has an exhaust-gas outlet ( ). An inner wall ( ) as well as a catalytic converting element ( ) are provided in the inner space ( ) of the muffler housing ( ). The catalytic converting element ( ) is mounted between the exhaust-gas inlet ( ) and the exhaust-gas outlet ( ). In order to ensure an adequate catalytic converting treatment of the exhaust gas at low gas counterpressure, it is provided to divide the entering exhaust-gas flow ( ) and to conduct at least one of these component flows ( ) in contact with the catalytic converting element ( ). The component flows ( ) are brought together and mixed with other before exiting from the muffler housing ( ).

Exhaust muffler comprising a catalytic converter

The invention relates to a vibration damper between a housing ( ), which holds an internal combustion engine, and a handle ( ) fixed on the housing ( ). The handle ( ) is for holding and guiding the motor-driven chain saw ( ) during use thereof. The vibration damper ( ) is a coil spring ( ) which is fixed at a first end ( ) thereof with an attachment element ( ) to the handle ( ) and, at a second end ( ), the coil spring is fixed with a further attachment element ( ) to the housing. A part turn of the end ( ) of the coil spring ( ) is held form-tightly to the attachment element ( ) in the direction of its longitudinal center axis ( ). To provide a torsion-free assembly of the coil spring, it is provided that the coil spring ( ) can be assembled from one of its ends ( ) between the handle ( ) and the housing ( ) and be secured at least at one of its ends ( ) to the attachment element ( ) against a rotational movement in the peripheral direction.

Vibration damper

A manually guided, portable implement, especially a power saw, is provided. The implement has a cylinder and a crankshaft that is connected to a piston via a piston rod. The implement has an essentially plastic housing as well as a lower crankcase. A stabilizing plate is nearly entirely embedded in the material of the lower crankcase. The one-piece stabilizing plate is provided with support sockets for bolting the lower crankcase to the cylinder. An overall metallic screw connection can thus be established.

Portable implement, especially power saw

A hand-held working tool has a housing and an internal combustion engine arranged in the housing and comprising a crankshaft and an air filter. A tool is driven by the crankshaft of the internal combustion engine. A fan housing is attached to the engine housing and has an air inlet. A fan wheel is arranged in the fan housing and is driven by the crankshaft of the internal combustion engine to supply cooling air, sucked in through the air inlet, to the internal combustion engine. The fan housing has a bottom extending radially to the crankshaft. The bottom and a side of the fan wheel facing the bottom define a chamber in the fan housing. The bottom has a combustion air outlet. A combustion air channel is connected to the combustion air outlet and to the air filter. The combustion air outlet is axially supplying combustion air from the chamber through the combustion air channel into the air filter of internal combustion engine. The fan housing has a channel wall having a bottom portion connected to the face of the bottom remote from the fan wheel and covering the bottom partially to form a double-walled bottom. The end face portion of the combustion air channel is defined by the bottom and the bottom portion of the channel wall. In an alternative embodiment the combustion air channel is provided in a hollow beam of a support that supports the drive unit of the working tool.

Hand-held working tool

The invention relates to a drive unit of a portable handheld work apparatus such a motor-driven chain saw having an internal combustion engine. The crankshaft of the engine drives a tool of the work apparatus and a fan wheel. The fan wheel is held within a fan housing on a drive pin of the crankshaft. A crankcase is rigidly connected to a cylinder of the engine and is made of a metal material. The crankcase is configured of two parts and the axis of the crankshaft lies in the partition plane of the crankcase housing parts which can be connected to each other. A metallic chassis of the drive unit includes a crankcase sump as one of the crankcase halves and has a flange surface lying essentially perpendicularly to the crankshaft axis. The flange surface is at least defined in sections by the free-lying end of the crankcase sump. In this way, the weight and the manufacturing costs of the work apparatus are reduced. The fan housing is made of plastic and is attached to and lies against the flange surface with its housing base.

Growing community of inventors

Stuttgart, Germany

Bernhard Dürr

Growing community of inventors

Stuttgart, Germany

Bernhard D&uuml;rr

Bernhard Dürr