Patent ID: 8132646

Claim:
An exhaust gas muffler for an internal combustion engine, comprising: a housing having an inlet adapted to receive exhaust gas from said internal combustion engine, an outlet that leads from the interior of said housing to the outside of the housing, and an outer wall, wherein in the interior of said housing exhaust gas flows along an inner surface of said outer wall in a first direction of flow to said outlet, wherein said outlet and said outer wall are configured such that said exhaust gas is adapted to flow out of said outlet, to the outside of said housing, and is deflected such that it flows over said outer wall approximately in a counter direction to said first direction of flow, wherein said exhaust gas flows out of said outlet at an angle of about 2° to about 10° relative to said outer wall of said housing, wherein said angle and a flow velocity of said exhaust gas are such that due to an underpressure resulting from said angle of the direction of flow of said exhaust gas flowing out of said outlet relative to said outer wall of said housing, atmospheric air is adapted to be drawn in between said exhaust gas and an outer surface of said outer wall of said housing to thereby effect an active cooling of said outer wall of said housing via said drawn-in atmospheric air, wherein two chambers are provided in said housing and are successively arranged in a direction of flow of said exhaust gas, wherein a catalytic converter is disposed between said two chambers, and wherein a spark arrestor screen is disposed, relative to a flow path of exhaust gas, between a second one of said chambers and a channel formed in an interior of said housing.