Patent ID: 7708114

Claim:
A muffler for an internal combustion engine comprising: (a) a housing having an inlet end with at least one inlet opening formed for a flow of exhaust gases into said housing and an outlet end with an outlet opening formed for a discharge of exhaust gases from said housing; (b) a first chamber, a second chamber, a third chamber and a fourth chamber sequentially arranged within said housing; (c) a perforated pipe passing longitudinally through a central region of both said first and said second chambers such that said perforated pipe extends partially into said first chamber, extends a full length of said second chamber and terminates at a partition separating said second and third chambers; (d) said third chamber containing a deflection element, said perforated pipe configured so as to open at its downstream end into said third chamber, thereby directing said exhaust gases toward said deflection element; and (e) a fourth chamber configured to channel a flow of gas to said outlet opening; wherein said perforations allow said exhaust gases to enter said perforated pipe so as to be directed through an unblocked interior of said perforated pipe and into said third chamber and a partition separating said first and said second chambers includes a hole that enables some of said exhaust gases to pass from said first chamber into said second chamber without passing through said central perforated pipe and all of said exhaust gases pass from said second chamber into said third chamber only through said downstream end of said perforated pipe.