US3191715A

US3191715A - Muffler

Info

Publication number: US3191715A
Application number: US283265A
Authority: US
Inventors: Paul F Jettinghoff
Original assignee: Walker Manufacturing Co
Current assignee: Walker Manufacturing Co
Priority date: 1963-05-27
Filing date: 1963-05-27
Publication date: 1965-06-29
Anticipated expiration: 1982-06-29

Description

June 29, 1965 P. F. JETTINGHOFF MUFFLER Filed May 27, 1963 INVENTOR Ew/ 217277171; 20%

United States Patent 3,191,715 MUFFLER Paul F. Jettinghofi, Jackson, Mich, assignor to Walker Manufacturing Company, a corporation of Delaware Filed May 27, 1963, Ser. No. 233,265 Claims. (Cl. 181-47) This invention relates to mufilers for automotive exhaust systems.

It is an object of the invention to provide a tri-flow gas path in an extremely small size muffler.

It is another object of the invention to provide a rnufiier for effectively silencing the intermediate frequency range of exhaust gas noises which is especially adapted for use in the newly developed tailpipe silencing exhaust system of the present assignee wherein a multiplicity of small diameter (about 4 inches maximum) silencing components are distributed throughout the entire length of an exhaust system.

The invention comprises a three-part rnufiier in which a pair of overlapped tubes inside a shell provide a tri-flow path for gas flowing through the mufiier.

The invention is illustrated in the accompanying drawings in which:

FIGURE 1 is a longitudinal cross section through a mufiier embodying the invention; and

FIG. 2 is a cross section along the line 22 of FIG. 1.

The mufiler 1 has a shell 3, an inlet tube 5, and an outlet tube 7. The tubes 5 and 7 are inclined to the axis of the shell but substantially parallel to each other. They overlap and are spotwelded together as indicated by the x.

The shell 3 is originally an open ended cylinder having the large diameter shown in the drawings. The overlapped tubes are inserted in such cylinder and then the ends thereof are reducedin a suitable manner, preferably by a swaging (axial compression) operation so that the ends of the shell are formed into end walls 9 and 11 and inlet and

outlet bushings

13 and 15. In this process the outer ends of tubes 5 and 7 are aligned with and brought into a tight press fit with the insides of

bushings

13 and 15, as seen at 17 and 19. They are then spotwelded to the bushings as seen by the Xs. The

bushings

13 and 15 may extend beyond the ends of the tubes 5 and 7, as shown, to provide a means for connection to other components in an exhaust gas system.

The walls of tubes 5 and 7 are louvered, as seen at 21 and 23, preferably over the full length thereof that is inside of the gas flow chamber 25 formed by shell 3. The bulk of the gas entering the inlet bushing 13 will flow out of the outlet end 27 of tube 5 and then must reverse its' direction of flow and flow back through'chamber 25 and then reverse again to enter the inlet end 29 of the tube 7 to flow out of the muffler through bushing 15. High pressure pulses of gas can expand out through the louvers in each tube to be silenced in chamber 25. Some cross bleeding or flow through the louvers 21 and 23 can take place to provide for minimum back pressure.

Patented June 29, 1965 ice In a commercial embodiment for certain 1963 US. automotive exhaust systems, the tube 5 is of 2 inches OD. and the tube 7 is 1% inches OD. The

bushings

13 and 15 are 2 inches I.D., the end 19 of tube 7 being expanded during the swage down of the outlet bushing 15 by use of a suitable expansion mandrel. The louvers are .060 inch round type. Tube 5 is 7 /4 inches long and tube 7 is 6 inches long. The length of chamber 25 is about 11 /2 inches. The outer diameter of shell 3 is about 4 inches and the inner wall thereof contacts the edges of the tubes 5 and 7 at the overlap to provide lateral support against rattling.

It will be seen that despite the small size of the muffler 1 substantial break-up of slugs of gas occurs and effective silencing of intermediate frequencies can occur with a minimum back pressure. The louvers themselves will also act to silence some of the high frequency noise in the gas.

While the inlet and outlet bushings 13 and 15 are shown in axial alignment, it is possible that in some applications it may be desirable to ofiset their respective axes.

I claim: 7

1. A small size tri-flow muffler consisting of only three parts, said three parts being an inlet tube and an outlet tube partially overlapping the inlet tube so that gas flowing from one to the other must reverse its direction of flow twice, the third of said three parts being an outer shell of no more than about 4 inches outer diameter providing a chamber surrounding said inlet and outlet tube, said shell having reduced diameter end portions forming an inlet bushing and an outlet bushing, said bushings being in tight engagement respectively with ends of the inlet and outlet tubes, the inner diameter of the shell being substantially the same as the maximum width of said two tubes at the overlapped portion whereby said tubes contact said shell and said shell furnishes lateral support for the overlapped ends of said tubes.

2. The invention set forth in claim 1 wherein the wall of said inlet tube inside said shell is louvered.

3. The invention set forth in claim 1 wherein the wall of said outlet tube inside said shell is louvered.

4. The invention set forth in claim 1 wherein the walls of said inlet and outlet tubes inside said shell are louvered.

5. The invention set forth in claim 1 wherein the overlapped portion of said inlet and outlet tubes are spotwelded together and said tubes are spotwelded to said bushings.

References Cited by the Examiner UNITED STATES PATENTS 1,991,748 2/35 Johnson.

2,138,477 11/38 LudloW 18l-54 2,357,791 9/44 Powers 18l54 2,548,965 4/51 Gaugler 181-36.2 2,583,366 1/52 Engels.

LEO SMILOW, Primary Examiner.

Claims

1. A SMALL SIZE TRI-FLOW MUFFLER CONSISTING OF ONLY THREE PARTS, SAID THREE PARTS BEING AN INLET TUBE AND AN OUTLET TUBE PARTIALLY OVERLAPPING THE INLET TUBE SO THAT GAS FLOWING FROM ONE TO THE OTHER MUST REVERSE ITS DIRECTION OF FLOW TWICE, THE THIRD OF SAID THREE PARTS BEING AN OUTER SHELL OF NO MORE THAN 4 INCHES OUTER DIAMETER PROVIDING A CHAMBER SURROUNDING SAID INLET AND OUTLET TUBE, SAID SHELL HAVING REDUCED DIAMETER END PORTIONS FORMING AN INLET BUSHING AND AN OUTLET BUSHING, SAID BUSHINGS BEING IN TIGHT ENGAGEMENT RESPECTIVELY WITH ENDS OF THE INLET AND OUTLET TUBES, THE INNER DIAMETER OF THE SHELL BEING SUBSTANTIALLY THE SAME AS THE MAXIMUM WIDTH OF SAID TWO TUBES AT THE OVERLAPPED PORTION WHEREBY SAID TUBES CONTACT SAID SHELL AND SAID SHELL FURNISHES LATERAL SUPPORT FOR THE OVERLAPPED ENDS OF SAID TUBES.