Stamp formed muffler

An exhaust muffler comprising:

• a pair of stamp formed internal plates secured in face to face relationship and defining an inlet tube having at least one array of perforations therein, an outlet tube having at least one array of perforations therein, a pair of generally registered apertures extending through said internal plates, and a tuning tube extending from said outlet tube to said apertures;
• and
• a pair of stamp formed external shells secured to and substantially surrounding said internal plates, said external shells being stamp formed to define a low frequency resonating chamber surrounding and in communication with said apertures in said internal plates and to define an expansion chamber surrounding the arrays of perforations in said inlet and outlet tubes.

A muffler comprising a pair of internal plates disposed in face to face relationship, said internal plates being stamp formed to define at least one inlet tube, at least one outlet tube in communication with said inlet tube, a plurality of tuning tubes in communication with at least one of said inlet and outlet tubes and a corresponding plurality of substantially enclosed low frequency resonating chambers in communication respectively with each said tuning tube, said inlet and outlet tubes each comprising an array of perforations therein, said muffler further comprising a pair of external shells substantially surrounding said internal plates and secured thereto, said external shells being stamp formed to define at least one expansion chamber in communication with said perforations in said inlet and outlet tubes.

A muffler for mounting to at least one exhaust pipe and comprising one tail pipe of a vehicle, said muffler comprising:

• a pair of internal plates securely connected to one another in generally face to face relationship, said internal plates being stamp formed to define first and second pairs of generally aligned apertures extending therethrough, the stamp formed internal plates further defining an inlet tube connectable to the exhaust pipe of the vehicle and extending to the first pair of apertures, said inlet tube further comprising at least one array of perforations therein, the stamp formed internal plates further comprising an outlet tube connectable to the tail pipe of the vehicle and having at least one array of perforations therein, and a tuning tube extending from the outlet tube to the second pair of apertures;
• and
• a pair of external shells secured to said internal plates, said external shells being stamp formed to define a low frequency resonating chamber surrounding said apertures in said internal plates and a high frequency tuning chamber surrounding the perforation arrays in said inlet and outlet tubes.

A stamp formed muffler comprising:

• first and second internal plates secured in generally face to face relationship and stamp formed to define an array of tubes therebetween, said array of tubes comprising an inlet tube, a return tube in communication with said inlet tube and an outlet tube in communication with said return tube, said first internal plate being characterized by arrays of perforations in the portions thereof defining the inlet and return tubes, said second internal plate including arrays of perforations extending through portions thereof defining the return and outlet tubes;
• and
• first and second stamp formed external shells secured respectively to said first and second stamp formed internal plates, said first external shell defining an expansion chamber enclosing and in communication with the perforations in the first internal plate, the second external shell being stamp formed to define an expansion chamber in communication with the perforations in said second internal plate.