Noise abatement muffler

A noise abatement muffler for an internal combustion engine, said muffler comprising:

• a housing having a plurality of isolated, serially arranged chambers therein,
• said housing having an inlet port, first fluid conducting means extending through said inlet port to conduct exhaust gases to one of said isolated chambers,
• said housing including exhaust port means located between said inlet port and said one of said isolated chambers, said exhaust port means being located at an acute angle relative to said inlet port,
• certain of said chambers being interconnected by second fluid conducting means for enabling exhaust gases transported to said one of said chambers by said first fluid conducting means to flow from said one of said chambers to another one of said chambers in a direction opposite to the flow of gases transported by said first fluid conducting means, and
• said another one of said chambers having a porous partition member for enabling said exhaust gases transported to said another one of said chambers by said second fluid conducting means to flow from said another one of said chambers in a direction opposite to the flow of gases transported by said second fluid conducting means to exit said housing through said exhaust port means.

A noise abatement muffler for an internal combustion engine, said muffler comprising:

• a housing having a plurality of isolated, serially arranged chambers therein,
• said housing having an inlet port, first fluid conducting means extending through said inlet port to conduct exhaust gases to one of said isolated chambers,
• said housing including exhaust port means located between said inlet port and said one of said isolated chambers,
• certain of said chambers being interconnected by second fluid conducting means for enabling exhaust gases transported to said one of said chambers by said first fluid conducting means to flow from said one of said chambers to another one of said chambers in a direction opposite to the flow of gases transported by said first fluid conducting means, and
• said another one of said chambers having a porous partition member for enabling said exhaust gases transported to said another one of said chambers by said second fluid conducting means to flow from said another one of said chambers in a direction opposite to the flow of gases transported by said second fluid conducting means to exit said housing through said exhaust port means, said porous partition member including a plurality of apertures on a portion thereof, said apertures being located in that portion of said porous partition member which is most distant from the location of said exhaust port means on said housing.

A noise abatement muffler for an internal combustion engine, said muffler comprising:

• a housing having a plurality of isolated, serially arranged chambers therein,
• said housing having an inlet port, first fluid conducting means extending through said inlet port to conduct exhaust gases to one of said isolated chambers,
• said housing including exhaust port means located between said inlet port and said one of said isolated chambers,
• certain of said chambers being interconnected by second fluid conducting means for enabling exhaust gases transported to said one of said chambers by said first fluid conducting means to flow from said one of said chambers to another one of said chambers in a direction opposite to the flow of gases transported by said first fluid conducting means, said one of said chambers receiving said exhaust gases from said first fluid conducting means being separated from the other chambers in said housing by a non-porous partition member, and
• said another one of said chambers having a porous partition member for enabling said exhaust gases transported to said another one of said chambers by said second fluid conducting means to flow from said another one of said chambers in a direction opposite to the flow of gases transported by said second fluid conducting means to exit said housing through said exhaust port means.

A noise abatement muffler for an internal combustion engine, said muffler comprising:

• a housing having a plurality of isolated, serially arranged chambers therein,
• said housing having an inlet port, first fluid conducting means extending through said inlet port to conduct exhaust gases to one of said isolated chambers,
• said housing including exhaust port means located between said inlet port and said one of said isolated chambers,
• certain of said chambers being interconnected by second fluid conducting means for enabling exhaust gases transported to said one of said chambers by said first fluid conducting means to flow from said one of said chambers to another one of said chambers in a direction opposite to the flow of gases transported by said first fluid conducting means, said exhaust port means being located in an additional chamber disposed between said one of said chambers and said another one of said chambers, and
• said another one of said chambers having a porous partition member for enabling said exhaust gases transported to said another one of said chambers by said second fluid conducting means to flow from another one of said chambers in a direction opposite to the flow of gases transported by said second fluid conducting means to exit said housing through said exhaust port means.

A noise abatement muffler for a stationary, low horsepower, internal combustion engine, comprising:

• a housing having forward and rear, serially arranged chambers separated from each other by an intermediate chamber between said forward and rear chambers,
• said housing having an inlet port, and first fluid conducting means extending through said inlet port to conduct exhaust gases to said rear chamber,
• said housing having exhaust port means located in said intermediate chamber for removal of said exhaust gases from said housing,
• said forward and rear chambers being interconnected by a second fluid conducting means for enabling exhaust gases transported to said rear chamber by said first fluid conducting means to flow from said rear chamber to said forward chamber,
• said rear chamber being separated from said intermediate chamber by a non-porous partition member, and
• said forward chamber being separated from said intermediate chamber by a porous partition member having apertures therein for enabling exhaust gases transported to said forward chamber from said rear chamber by said second fluid conducting means to flow into said intermediate chamber to thereby exit said housing through said exhaust port means within said intermediate chamber at a sound pressure level in the range of 10-25 decibels lower than the sound pressure level of the exhaust gases received at said inlet port.