Combined muffler and catalytic converter exhaust unit

Claim 1

A combined muffler and catalytic converter comprising: an elongate housing having inlet and outlet ends joined by a body section, inlet and outlet openings respectively in said inlet and outlet ends, first and second transverse baffle plates across said body section spaced respectively from said first and second ends, and a separator plate in said body section extending between said baffles; said housing, baffles and plate defining (i) a first expansion chamber between said outlet end and said second baffle, (ii) a second expansion chamber between said inlet end and said first baffle, (iii) a converter chamber between said first and second baffles on a first side of said plate, said converter chamber having an inlet and an outlet opening respectively in said first and second baffles, and (iv) a resonance chamber between said first and second baffles on a second side of said plate, said resonance chamber having a first resonance chamber inlet through said second baffle from said first expansion chamber, a first resonance chamber outlet into said second expansion chamber through said first baffle, a second resonance chamber inlet from said second expansion chamber through said first baffle, and a second resonance chamber outlet through said second baffle; an inlet pipe from said inlet of said housing to said inlet of said converter chamber; a first perforated pipe extending between said first resonance chamber inlet and said first resonance chamber outlet and a second perforated pipe extending between said second resonance chamber inlet and said second resonance chamber outlet; an outlet pipe between a second resonance chamber outlet and said outlet of said housing; and an oxidation/reduction catalyst in said converter chamber; whereby, subject to cross-flows through perforations of said perforated pipes, a flow path is defined through said inlet pipe, through said converter chamber, through said first expansion chamber, through said first perforated pipe, through said second expansion chamber, through said second perforated pipe and finally through said outlet pipe.