Abstract: The invention pertains to an automatic decompression device for valve-controlled internal combustion engines, having at least one camshaft for the actuation of gas shuttle valves and a decompression lever, which acts in cooperation with at least one gas shuttle valve and which is attached in a pivoting fashion on the camshaft on an axis of rotation, and which can be moved against a spring force from a first switch position into a second switch position as a result of the centrifugal forces acting on it during the revolution of the camshaft. It is suggested that the decompression lever be designed as a bow element the two ends of which are attached to the camshaft. The decompression arrangement is distinguished by a simple design, and is especially well-suited for small engines due to its lightweight construction.

Abstract: The invention pertains to an internal combustion engine with a crankcase, a crankshaft and a camshaft for controlling at least one intake and exhaust valve, as well as an oil pump for delivering lubricating oil to the crankshaft. Downstream on the outlet side of the oil pump is an oil pressure regulating valve for limiting the oil pressure. The valve gate, which is contacted by a spring element in the closing direction, depending on the amount of oil delivered and/or the oil temperature, the valve gate frees an opening that can be connected with the inlet side of the oil pump. It is suggested that the camshaft be seated in longitudinally displaceable fashion within the crankcase and form the valve gate of the oil pressure control valve. An oil pressure-limiting valve for an internal combustion engine is thus implemented in a simple way.

Abstract: The invention pertains to an internal combustion engine with a crankcase, a crankshaft and a camshaft for controlling at least one intake and exhaust valve, as well as an oil pump for delivering lubricating oil to the crankshaft. Downstream on the outlet side of the oil pump is an oil pressure regulating valve for limiting the oil pressure. The valve gate, which is contacted by a spring element in the closing direction, depending on the amount of oil delivered and/or the oil temperature, the valve gate frees an opening that can be connected with the inlet side of the oil pump. It is suggested that the camshaft be seated in longitudinally displaceable fashion within the crankcase and form the valve gate of the oil pressure control valve. An oil pressure-limiting valve for an internal combustion engine is thus implemented in a simple way.

Abstract: The invention pertains to an automatic decompression device for valve-controlled internal combustion engines, having at least one camshaft for the actuation of gas shuttle valves and a decompression lever, which acts in cooperation with at least one gas shuttle valve and which is attached in a pivoting fashion on the camshaft on an axis of rotation, and which can be moved against a spring force from a first switch position into a second switch position as a result of the centrifugal forces acting on it during the revolution of the camshaft. It is suggested that the decompression lever be designed as a bow element the two ends of which are attached to the camshaft. The decompression arrangement is distinguished by a simple design, and is especially well-suited for small engines due to its lightweight construction.

Abstract: The invention aims to provide a compact four-stroke engine with rotary valve control and petroil lubrication which has a simplified construction and allows the engine to be used in any position as a result of an improved lubrication system. To this end, the carburetor is directly connected to the inlet opening and the rotary valve is configured in such a way that in a first position it connects the carburetor to the combustion chamber, in a second position it connects the carburetor to the cylinder chamber/crankcase via the overflow conduit and in a third position it connect the cylinder chamber/crankcase to the combustion chamber via the overflow conduit and the combustion chamber to the outlet opening via the conduit. Said rotary valve is in continuous motion during the operation of the combustion engine and the first, second and third positions only occur at corresponding defined moments.

Abstract: In order to create a compact four-cycle internal combustion engine with mixture lubrication comprising a cylinder which is closed on top by a cylinder head and which changes below into a crankcase, in the cylinder a piston moving up and down, in the cylinder head an intake port with an admission valve and an exhaust conduit with an exhaust valve, a carburetor for forming an oil-fuel-air mixture lubricating the engine, as well as means by which a mixture is transported within each engine cycle from the carburetor into the crank chamber closed by the crankcase and from the crank chamber into the intake port, engine which is constructed in a simple way and which is characterized by a good charging behavior, it is proposed that the carburetor is connected outside the crank chamber with the intake port.

Abstract: 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 (1) which is assembled of two housing shells (2, 3). The one housing shell (2) has an exhaust-gas inlet (4) and the other housing shell (3) has an exhaust-gas outlet (5). An inner wall (8) as well as a catalytic converting element (7) are provided in the inner space (6) of the muffler housing (1). The catalytic converting element (7) is mounted between the exhaust-gas inlet (4) and the exhaust-gas outlet (5). 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 (10) and to conduct at least one of these component flows (23) in contact with the catalytic converting element (7). The component flows (22, 23) are brought together and mixed with other before exiting from the muffler housing (1).

Abstract: A muffler for a two-stroke internal combustion engine has a housing enclosing a hollow space and having an exhaust gas inlet and an exhaust gas outlet. Shaped sheet metal members are mounted in the housing and define an exhaust gas flow channel. The flow channel extends at least over a portion of its length in a plane of the sheet metal members. A first one of the sheet metal members has a projecting portion projecting from the plane of the sheet metal members and forming a connector of the flow channel. The connector communicates with the exhaust gas inlet. A second one of the sheet metal members has a projecting portion projecting from the plane of the sheet metal members and forming an end portion of the flow channel opening into the hollow space of the housing.