US3613828A - Multilouver roughness silencer - Google Patents

Abstract

A muffler has a sinuous louvered partition extending longitudinally of the casing and alongside a straight-through gas flow tube to provide a series of expansion chambers that are in parallel with the gas flow through the muffler.

Description

United States Patent Bert DuBois Brooklyn, Mich. Appl. No. 58,394

Filed July 27, 1970 Patented Oct. 19, 1971 Assignee Tenneeo lne. Racine, Wis.

Inventor MULTILOUVER ROUGHNESS SILENCER 5 Claims, 2 Drawing Figs.

US. Cl 181/48, 181/63 Int. Cl F0ln ll04,

FOln 1/ 10 Field of Search 181/48,

[5 6] References Cited UNITED STATES PATENTS 2,038,309 4/1936 Oldberg 3,485,319 12/1969 Balluff FOREIGN PATENTS 822,559 9/1937 France 394,713 12/ 1 965 Switzerland Primary Examiner-Robert S. Ward, Jr. Attorney-Harness, Dickey & Pierce ABSTRACT: A muffler has a sinuous louvered partition extending longitudinally of the casing and alongside a straightthrough gas flow tube to provide a series of expansion chambers that are in parallel with the gas flow through the muffler.

MULTILOUVER ROUGI'INESS SILENCER BRIEF SUMMARY OF THE INVENTION It is the purpose of this invention to provide a low back pressure muffler containing silencing structure that substantially DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal cross section of a muffler, shown somewhat schematically, embodying the invention; and FIG. 2 is a cross section along the line 22 of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION The muffler 1 has a tubular housing 3 which is preferably of oval cross section as seen in FIG. 2. The opposite ends of the housing 3 are closed by an inlet header 5 and an outlet header 7 which are interlocked in gastight joints 9 with the ends of the shell 3. The headers 5 and 7 have outwardly extending collars 11 and 13 which receive a straight-through gas flow tube 15 that can conduct gas straight through the muffler 1 from the exhaust pipe 17 to the tailpipe 19.

The tube 15 is perforated, preferably in form of louvers 21 extending over a substantial portion of its length within the housing 3 as can be seen in FIG. 1. The tube 15 is preferably located off center of the oval-shaped housing 3 as can be seen in FIG. 2. A sinuously shaped longitudinal partition 23, which extends longitudinally of the muffler and parallel to the tube 15, is located to one side of the tube 15 to define a chamber 25 extending longitudinally of the shell 3 and containing tube 15.

The partition 23 is bent back and forth to provide a series of longitudinally extending partition sections 27, 29, 31, and 33 which subdivide the rest of the space within the housing 3 into transversely separated longitudinal chambers 35, 37, 39, and 41. The partition sections are interconnected by transverse sections 43, 45, and 47, which are located on alternately located or opposite sides of the partition 23, and which engage and are spotwelded to the shell 3 along with flanges 49 and 51 which extend outwardly from the two end partition sections 27 and 33. Preferably, the partition 29 terminates a short distance from each header 5 and 7, as seen in FIG. 1, whereby the end chamber 41 and intermediate chambers are connected by transverse end chambers 53 and 55 to the chamber 25. Each of the partition sections 27, 29, 31, and 33 is perforated, preferably by louvers 57 extending over most of its area and along substantially all of its length and aligned with each other and with the louve'red area in tube 15.

In operation the gas entering the muffler 3 encounters very little resistance since it can flow straight through the pipe 15 with the result that there is minimum horsepower loss due to back pressure. Noise-producing gas pulses can expand radially or transversely out of the gas tube 1 through the louvers 21 and into the chamber 25 and further, in series, through successive ones of the partition sections 27, 29, 31, and 33 and the chambers formed by them. The multiple-series louver structure located in parallel with the tube 15 therefore provides a mass of means for attenuating high-frequency sounds and roughness as well as medium frequencies. By locating the muffler 1 so that an antinode or maximum pressure point of a troublesome lower frequency falls in a central portion of the tube 15, attenuation of such lower frequencies is also accomplished.

The structure described has substantially the acoustic effect of fibrous acoustic material packed around the tube 15 or packed within the muffler. It therefore produces attenuation of the type desired by drivers of sports vehicles, i.e., high and medium frequencies and roughness are attenuated whereas some of the lower frequency, power sound remains. Additionally, the partition means 23 strengthens the oval shell 3 to control shell noise and how].

I claim: 1. A muffler comprising a housing a oval cross section having an inlet at one end and an outlet at the other end, a straight-through perforated gas flow tube connecting the inlet and outlet for straight-through flow of gas through the housing, and means providing a plurality of perforated longitudinal partitions extending substantially parallel to each other and to the flow tube and secured at opposite sides to the housing.

2. A muffler as set forth in claim I wherein said means comprises a sinuous member having walls providing said partitions.

3. A muffler as set forth in claim 2 wherein the tube and partitions are perforated by means of louvers.

4. A muffler as set forth in claim 1 wherein said partitions terminate inwardly of the ends of the housing to provide transverse end chambers communicating with the gas flow tube.

5. A muffler as set forth in claim I wherein said longitudinal partitions are secured to the housing to provide antideflection support for the oval cross section thereof.

Claims (5)

1. A muffler comprising a housing a oval cross section having an inlet at one end and an outlet at the other end, a straightthrough perforated gas flow tube connecting the inlet and outlet for straight-through flow of gas through the housing, and means providing a plurality of perforated longitudinal partitions extending substantially parallel to each other and to the flow tube and secured at opposite sides to the housing.

2. A muffler as set forth in claim 1 wherein said means comprises a sinuous member having walls providing said partitions.

3. A muffler as set forth in claim 2 wherein the tube and partitions are perforated by means of louvers.

4. A muffler as set forth in claim 1 wherein said partitions terminate inwardly of the ends of the housing to provide transverse end chambers communicating with the gas flow tube.

5. A muffler as set forth in claim 1 wherein said longitudinal partitions are secured to the housing to provide antideflection support for the oval cross section thereof.

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