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Publication numberUS3209861 A
Publication typeGrant
Publication dateOct 5, 1965
Filing dateOct 28, 1963
Priority dateOct 28, 1963
Publication numberUS 3209861 A, US 3209861A, US-A-3209861, US3209861 A, US3209861A
InventorsWhitney William C
Original AssigneeWalker Mfg Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Muffler with two longitudinally separated chambers
US 3209861 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

Oct. 5, 1965 w. c. WHITNEY v 3,209,861

MUFFLER WITH TWO mucmunmnw, sannnsn cmuasns Filed Oct. 28, 1963 INVENTOR.

United States Patent 3,209,861 MUFFLER WITH TWO LONGITUDINALLY SEPARATED CHAMBERS William (1. Whitney, Jackson, Mich, assiguor to Walker Manufacturing Company, a corporation of Delaware Filed Oct. 28, 1963, Ser. No. 319,456 2 Claims. (Cl. 181-59) My invention relates to automotive exhaust mufflers.

It is an object of my invention to provide an improved sport or Hollywood-type exhaust mufller. The invention accomplishes this by means of a simple, two-part construction comprising an outer shell and an inner gas flow tube. The shell is pinched down at an intermediate point to contact the tube and divide the space between theshell and the tube in the two longitudinally separated chambers. One of these may be filled with glass fibers or suitable sound absorbent material.

The invention is illustrated in the accompanying drawings in which:

FIGURE 1 is a longitudinal cross section through the muffler of this invention; and

FIG. 2 is a cross section along the line 2-2 of FIG. 1.

The mufller 1 has an outer shell 3 which is preferably formed from a tubular piece of metal which is swaged down to form an inlet end 5 and an outlet end 7 which are provided respectively with an inlet bushing 9 and an outlet bushing 11 for attachment to an exhaust pipe and a tailpipe in an automotive exhaust system. Inside of the shell 3 is a louvered gas flow tube 13 which is seated at opposite ends in the bushings 9 and 11 of the shell 3 and preferably spotwelded at x to one of them. The tube 13 may be provided with a restriction 15 which can be formed by rolling a reduced diameter section in the tube. The tube 13 is also provided with banks of louvers 17 which open into the space between the tube 13 and the shell 3.

The shell 3 is pinched down into contact with the tube 13 by pinching together folds of metal 19 so as to reduce the intermediate portions 21 into wrap around contact with the outside diameter of the tube 13. This divides the inside of the casing 3 into a chamber 23 upstream of the folds 19 and the chamber 25 downstream of the folds 19. One of the chambers, preferably the downstream chamber 23, is filled with sound absorbent material such as glass pack.

In operation, gas will enter the inet bushing 9 and flow lengthwise through the tube 13 to flow out of the unit through the outlet bushing 11. The restriction 15 imposes a controlled amount of back pressure on the gas and therefore facilitates an improves the silencing effect of the muffler 1. The gases passing through the tube 13 communicate with the space 23 where many of the intermediate and high frequency sounds are attenuated. A

substantial amount of additional attenuation occurs in the glass pack section 25. The intermediate and high frequencies are removed also by the glass pack 25 so that the unit as a whole has a substantially high eificiency in removing intermediate and high frequencies without utilizing a very large amount of glass pack material. The presence of the restriction 15 upstream of the glass pack tends to protect the glass pack againt loss by erosion, as

well as improve the silencing characteristics of the unit. The low frequencies are not effectively removed by this device so that it constitutes the Hollywood or sport-type mufiler which leaves the low power note in the exhaust system.

Modifications may be made without departing from the spirit and scope of the invention.

I claim:

1. A Hollywood type exhaust muffler for internal combustion engines comprising an outer shell of substantially uniform cross-sectional area throughout the major portion of its length with an intermediate section of reduced cross-section, an inner tube extending through said outer shell and engaged substantially around its periphery by said intermediate section to divide the space between said inner tube and said outer shell into two longitudinally separated chambers, said inner tube providing a straight through flow path throughout the length of said outer shell of substantially constant cross-sectional area through the major portion of its length, said inner tube having a plurality of openings into each of said chambers, one of said chambers being empty, and a sound absorbent substance filling the other of said chambers.

2. A Hollywood type exhaust mufiier as set forth in claim 1 wherein the inner tube is formed With an integral flow restriction of reduced cross-sectional area in one of said chambers.

References Cited by the Examiner UNITED STATES PATENTS 2,047,442 7/36 Starkweather et al 181-48 2,047,443 7/ 36 Starkweather, et al 181-35 2,056,608 10/36 Jack 181-42 X 2,194,457 3/40 Cary 181-35 2,251,880 8/41 Cary et al 181-48 2,367,753 1/45 Buck.

FOREIGN PATENTS 881,494 1/43 France.

988,370 4/51 France. 1,158,817 3/58 France. 1,063,136 12/53 France. 1,074,071 3/54 France.

892,780 3/ 62 Great Britain.

LEO SMILOW, Primary Examiner.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2047442 *Aug 15, 1935Jul 14, 1936Buffalo Pressed Steel CompanyMuffler
US2047443 *Mar 9, 1936Jul 14, 1936Buffalo Pressed Steel CompanyMuffler
US2056608 *Dec 22, 1933Oct 6, 1936C F Burges Lab IncSilencer
US2194457 *Jul 27, 1938Mar 26, 1940Hayes Ind IncMuffler construction
US2251880 *Apr 24, 1936Aug 5, 1941Hayes Ind IncMuffler and silencer construction
US2367753 *Apr 29, 1940Jan 23, 1945Hayes Ind IncMethod of making mufflers and the like
FR881494A * Title not available
FR988370A * Title not available
FR1063136A * Title not available
FR1074071A * Title not available
FR1158817A * Title not available
GB892780A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3263772 *Jun 17, 1964Aug 2, 1966Arvin Ind IncSound attenuating gas conduit with one-quarter wave-length side branch chambers
US3313373 *Jan 11, 1965Apr 11, 1967Midas Internat CorpMuffler with baffles formed as chordal flanges
US3323613 *Oct 26, 1964Jun 6, 1967Walker Mfg CoThree-part muffler with side branch chambers
US3415336 *Nov 14, 1966Dec 10, 1968Arvin Ind IncResonator and method of making it
US3500954 *Mar 13, 1969Mar 17, 1970Walker Mfg CoExhaust silencing system
US3752260 *Jul 15, 1971Aug 14, 1973Tenneco IncAir rush silencer
US3841435 *Nov 12, 1973Oct 15, 1974Tenneco IncSwaged tri-flow muffler
US4023645 *Feb 27, 1975May 17, 1977Donaldson Company, Inc.Method and apparatus for reducing aerodynamic whistle
US4109753 *Nov 19, 1976Aug 29, 1978Midas-International CorporationMuffler assembly
US6082487 *Feb 8, 1999Jul 4, 2000Donaldson Company, Inc.Mufflers for use with engine retarders; and methods
US6354398May 16, 2000Mar 12, 2002Donaldson Company, Inc.Mufflers for use with engine retarders; and methods
US7866442 *Dec 28, 2006Jan 11, 2011Yamaha Hatsudoki Kabushiki KaishaMuffler and vehicle equipped with muffler
U.S. Classification181/252
International ClassificationF01N1/00, F01N1/24
Cooperative ClassificationF01N1/003, F01N1/24
European ClassificationF01N1/24, F01N1/00B