Patent ID: 8042649

Claim:
A vehicular muffler comprising: a hollow outer case; a plurality of tubular inner sleeves, formed of porous material, which are disposed inside of the outer case and which are operatively connected, at a first end thereof, to an exhaust feed pipe; and an outlet pipe having a first end which is disposed inside of the outer case and which is operatively connected to the respective inner sleeves, said outlet pipe operable to discharge an exhaust gas to an outside environment via an outlet side of the outer case; wherein the tubular inner sleeves have openings formed therein along substantially the entire length thereof, and are spaced away from each other so as to be out of contact with one another; wherein the plurality of inner sleeves are connected to the exhaust feed pipe by way of a first expansion chamber comprising: a first connecting sleeve having a first sleeve diameter thereacross, a substantially disc-shaped enlarged portion disposed adjacent to and downstream from the first connecting sleeve, the enlarged portion having a maximum chamber diameter which is larger than the first sleeve diameter, a neck portion which is reduced in diameter to be smaller than the enlarged portion, and a plurality of outlet-side connecting sleeve portions, wherein the inner sleeves and the first expansion chamber are in fluid communication with one another such that during use, exhaust gas from the exhaust feed pipe flows into and through the disc-shaped enlarged portion and into the tubular inner sleeves; and wherein the inner sleeves are connected to the outlet pipe by way of a second expansion chamber which is similar in shape to the first expansion chamber.