# US 4,396,090 A · Muffler

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- Number: US 4,396,090 A
- Document ID: US4396090A
- Status: Granted
- Kind: A
- Application number: 06/361,042
- Filed: 1982-03-23
- Granted: 1983-08-02
- Earliest claimed: 1981-03-26
- Assignees: Construction Metallurgique de Wissembourg S.A. Wimetal
- Inventors: Gilbert Wolfhugel
- Web page: https://patentgrep.com/patent/US4396090A

## CPC

- F01N 13/1872: {the assembly using stamp-formed parts or otherwise deformed sheet-metal}
- F01N 1/084: {the exhaust gases flowing through the silencer two or more times longitudinally in opposite directions, e.g. using parallel or concentric tubes}
- F01N 1/10: in combination with sound-absorbing materials (F01N1/125 takes precedence)
- F01N 13/185: {the connection being realised by deforming housing, tube, baffle, plate, or parts thereof}
- F01N 13/1888: {the housing of the assembly consisting of two or more parts, e.g. two half-shells}
- F01N 2240/20: a flow director or deflector
- F01N 2310/02: Mineral wool, e.g. glass wool, rock wool, asbestos or the like
- F01N 2450/20: by mechanical joints, e.g. by deforming housing, tube, baffle plate or parts thereof
- F01N 2470/06: Tubes being formed by assembly of stamped or otherwise deformed sheet-metal
- F01N 2470/10: Tubes having non-circular cross section
- F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16)

## Abstract

A muffler for a motor vehicle is made up of a housing enclosing a pair of sheet metal plates impressed with semi-circular depressions with the plates combining to form a sinuously shaped gas duct of circular cross section. Walls positioned within the housing divide its interior into chambers. Perforations in the gas duct open into the chambers. Lugs are punched out of the sheet metal plates in a uniform pattern and the lugs in one plate are inserted through the corresponding punched openings in the other and are bent into locking engagement with the other plate. These lugs and the corresponding openings contribute to the mechanical strength of the muffler. The ends of the plates forming the inlet and outlet ends for the gas duct have flanges which also contribute to the mechanical strength of the muffler. Cooperating interfitting corrugations in the plates located at specific positions relative to the gas duct prevent partial short circuiting of the exhaust gas flow through the muffler.

## Claims

### Claim 1

A muffler comprising means forming a sound absorbing housing divided into chambers, means forming a sinuous shaped gas duct located within and extending through the chambers within said housing, said means forming said gas duct comprising a pair of sheet metal plates connected together and each of said plates having a semi-circular depression so that the semi-circular depressions in combination form a gas duct for the flow of exhaust gases through said housing, wherein the improvement comprises that each of said plates has punched out lugs forming openings in said plate so that said lugs in one said plate fit into the openings in the other said plate and are bent into engagement with the other said plate for securing said plates together, and means for preventing partial short circuiting between adjacent parts of the sinuously shaped gas duct comprising impressed corrugations in said plates disposed in interengaging form-locking relation.

### Claim 2 (depends on 1)

A muffler, as set forth in claim 1, wherein each of said plates has a front edge defining the inlet end of the gas duct and a rear edge defining the outlet end of the gas duct, and the front and rear edges of said sheet metal plates are bent out of the planes of said plates so that they form an angle of less than 90.degree. with the plate.

### Claim 3 (depends on 1, 2)

A muffler, as set forth in claim 1 or 2, wherein a gas deflector is positioned in said gas duct intermediate the ends thereof, said deflector having lugs thereon, at least one of said plates having openings therethrough arranged to receive said lugs of said deflector with said lugs bent into engagement with said at least one plate for securing said gas deflector within said gas duct.

### Claim 4 (depends on 1)

A muffler, as set forth in claim 1, wherein said lugs are arranged in each of said plates in a uniform spaced pattern so that said lugs in one said plate align with the openings in the other said plate.

### Claim 5 (depends on 1)

A muffler, as set forth in claim 1, wherein said housing has an inlet end and an outlet end, said gas duct extending from the inlet end to the outlet end of said housing, said gas duct comprising a plurality of side-by-side rectilinear parts interconnected by U-shaped curved parts so that the length of said gas duct within said housing is multiple of the length of said housing.