Exhaust gas muffler for an internal combustion engine

An exhaust gas muffler for an internal combustion engine such as a two-stroke engine for portable handheld tools such as motor-driven chain saws, the engine including 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 comprising:

• a housing having a shell-like wall defining a chamber for receiving the exhaust gas from the engine;
• said housing having a primary outlet opening formed in said wall for passing a primary component flow of said exhaust gas out of said chamber in a first direction;
• said housing having a secondary outlet opening formed in said wall for passing an additional flow of said exhaust gas out of said chamber;
• a cap extending over said secondary outlet opening and having an open end directed toward said primary outlet opening for directing a first portion of said additional flow in a second direction transverse to said first direction so as to cause said first portion to break up said primary component flow;
• and,
• said cap having an ancillary opening formed therein for directing a second portion of said additional flow in a third direction transverse to said second direction and toward said primary component flow to further break up the latter.

An exhaust gas muffler for an internal combustion engine such as a two-stroke engine for portable handheld tools such as motor-driven chain saws, the engine including 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 comprising:

• a housing having a shell-like wall defining a chamber for receiving the exhaust gas from the engine;
• said housing having a primary outlet opening formed in said wall for passing a primary component flow of said exhaust gas out of said chamber in a first direction;
• said housing having a secondary outlet opening formed in said wall for passing a secondary component flow of said exhaust gas out of said chamber in a second direction;
• a guide hood disposed over said primary outlet opening and having a hood opening for directing said primary component flow into the ambient in a first direction;
• said secondary outlet opening being disposed in front of said hood opening;
• and,
• guide means disposed at said secondary outlet opening for directing said secondary component flow toward and into said primary component flow to break up the latter to cause the same to become turbulent and mix with ambient air.