Abstract: A motor chain saw has a motor housing with a drive unit for driving a saw chain on a guide bar. The drive unit is an internal combustion engine with a cylinder and a crankshaft extending transversely to a longitudinal axis of the motor chain saw. A drive pinion is mounted on a first end of the crankshaft. A cooling air blower with a blower wheel is mounted on the second end of the crankshaft. A cooling air stream of the blower flows transversely to the longitudinal axis of the motor chain saw about the cylinder and exits through a housing opening. A hand guard arranged between a handle and a front end of the guide bar is connected with one leg near the housing opening for the cooling air stream. In front of the housing opening a baffle element is supported on the leg of the hand guard.

Abstract: A motor chain saw has a motor housing with a drive unit for driving a saw chain on a guide bar. The drive unit is an internal combustion engine with a cylinder and a crankshaft extending transversely to a longitudinal axis of the motor chain saw. A drive pinion is mounted on a first end of the crankshaft. A cooling air blower with a blower wheel is mounted on the second end of the crankshaft. A cooling air stream of the blower flows transversely to the longitudinal axis of the motor chain saw about the cylinder and exits through a housing opening. A hand guard arranged between a handle and a front end of the guide bar is connected with one leg near the housing opening for the cooling air stream. In front of the housing opening a baffle element is supported on the leg of the hand guard.

Abstract: The invention is directed to an exhaust gas muffler for an internal combustion engine such as a two-stroke engine for portable handheld tools such as a motor-driven chain saw. The engine includes a cylinder and a piston conjointly defining a combustion chamber wherein combustion gases are generated and discharged as a flow of exhaust gas during operation of the engine. The exhaust gas muffler includes a housing having a shell-like wall defining a chamber for receiving the exhaust gas from the engine. The housing has a primary outlet opening formed in the wall of the housing for passing a primary component flow of the exhaust gas out of the chamber in a first direction. The housing has a secondary outlet opening formed in the wall thereof for passing a secondary component flow of the exhaust gas out of the chamber in a second direction.