US3243012A - Muffler constructed to vaporize condensate from inner chambers - Google Patents

Description

March 29, 1966 w. H. POWERS MUFFLER coNsTRUcTED To vAPoRlzE coNDENsATE FROM INNER CHAMBERS original Filed April 2, 195e 8 Sheets-Sheet 1 INVENTOR. /5/ Zwerg. W4 l/em folv/sf March 29, 1966 w. H. POWERS 3,243,012

MUFFLER CONSTRUCTED TO VAPORIZE CONDENSATE FROM INNER CHAMBERS original Filed Apil 2, 1956 e sheets-sheet 2 IN V EN TOR. m/f y /7/ 270 we fs.

March 29, 1966 w. H. POWERS MUFFLER COHSTRUCTED TO VAPORIZE CONDENSATE FROM INNER CHAMBERS 8 Sheets-Sheet 5 original Filed April 2, 1956 8 Sheets-Sheet 4 March 29, 1966 w. H. POWERS MUFFLER cousTnucTED To vAPoRIzE coNDENsATE FROM INNER CHAMBERS original Filed April 2, 1956 w T Illlwuufqhhkv l l mmi. im VIII |||||H HHMV M HJf. Wl/ J.

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MUFFLER CONSTRUCTED TO VAPORIZE CONDENSATE FROM INNER CHAMBERS Original Filed April 2. 1956 8 Sheets-Sheet 5 March 29, 1966 w. H. POWERS MUFFLER CONSTRUCTED T0 VAPORIZE CONDENSATE FROM INNER CHAMBERS original Filed April 2, 195e 8 Sheets-Sheet 6 INVENTOR 10Q/7' 70 Zl/ 7s 5% *Pw l 4 Trax/vrsr March 29, 1966 w. H. PowERs 3,243,012

MUFFLER CONSTRUCTED TO VAPORIZE CONDENSATE FROM INNER CHAMBERS original Filed April 2, 195s a sheets-sheet v nu www. NNW www wwwwww wwww NN wwwwww wwwww ,w ,w w www www www .March 29, 1966 w. H. POWERS MUFFLER CONSTRUCTED TO VAPORIZE CONDENSATE FROM INNER CHAMBERS 8 Sheets-Sheet 8 Original Filed April 2, 1956 INVENToR. M/zer /9/ 77nd@ 71s.

United States Patent O "ice,

This case is a continuation of U. S. Serial No. 575,404, filed April 2, 1956 and now abandoned.

This invention relates to muffler constructions and, in particular, to mufflers of the type adapted to silence the exhaust stream of automotive internal combustion engines.

It is the object of this invention to provide a muiiier construction that may be economically manufactured and yet which is rugged and durable in construction and which will efficiently silence the powerful modern day automotive engines, particularly those having automatic transmissions, without appreciable back pressure.

It is an additional object of this invention to provide new and improved condensate disposal means within the muffler, which means is operative tocause vaporization of condensate within the muler and removal with the exhaust gases flowing through the mufiier.

The invention accomplishes these and other objects by means of a construction in which the gas passages Within the muffler casing are arranged in a multiple chamber tri-flow pattern and subjected to the action of a number of spit chambers lboth large and small which will remove the roughness and high frequency sounds. The gases and sounds are also exposed to the action of a number of resonator chambers which will act to remove the lower frequency heavy power notes. The internal triflow construction is of such a nature that it can be preassembled, that is, prepared as a subassembly and then inserted into the muler casing. Th-e over-all design is such as to meet the cost and performance requirements of automotive manufacturers, particularly those manufacturing V-8 engines.- In order to obtain :the desired acoustical characteristics, the muier is divided into a plurality of chambers some of which are connected directly in the gas flow path through the muffler and some indirectly in various manners. The acoustic arrangement of the internal silencing structure of the muffler is such as to result in substantial temperature differentials within the muffler during operation. Consequently, some parts of the muiiier will -be operated hot at temperatures sufiiciently high to cause vaporization of condensate in the muffler while other parts of the mullier will be operated at relatively col-d temperatures at which the condensate is not readily vaporized or not vaporized at all. As a result, therefore, some of the chambers in the mufiler are hot chambers Iand other are cold chambers. It has been Ifound that accumula-tion of condensate lin the cold chambers will greatly decrease muilier life. Therefore, this invention contemplates drainage means provided within the muffler to connect the cold chambers to the hot chambers so that condensate in the cold chambers can ow to the hot chambers and be vaporized therein for removal with the exhaust gases.

The invention is illustrated in modified Iforms in the accompanying drawings in which:

FIGURE l is a longitudinal section of a preferred form of the invention as taken on line 1.-1 of FIG. 3;

FIG. 2 is an end view taken from the left 0f FIG. 1;

FIG. 3 is a cross section taken Valong the line 33 of FIG. l, the louvers being omitted for simplification;

FIG. 4 is an enlarged side elevation of one of the gas conduits with parts broken away to show the structure of the louvers in the tube;

Y, 3,243,012 Patented Mar. 29,1966

FIG. 5 is a cross section through the louvers shown iny FIG. 4 and laid out straight rather than on the curved contour of the tube; v i

FIG. 6 is a longitudinal cross section through a slightly modified type of muffler, the end view and sectional view being the same for this muffler as FIGS. 2 and 3;

FIG. 6A is a section on line 6A-6A of FIG. 6;

FIG. 7 is an enlarged view, with portions Ibroken away,l of the front end of a muffler somewhat similar to the muffler shown in FIG. 6, the structure in FIG. 7 revealing a pancake inlet arrangement;

FIG. 8 is a section on line 8 8 of FIG. 7;

FIG. 9 is a perspective view showing a modified arrangement for forming the tri-flow passages in the mufiler, this constituting a pancake arrangement consisting of complemental stampings which when fitted together will define the spit chambers around the outermost passages and define the inner passage itself;

FIG. 10 is a longitudinal cross section of a modified form of muler;

FIG. 1l is an end view taken from the inlet side of the rn-uler of FIG. l0;

FIG. 12 is a cross section taken along the line 12--12 yof FIG.-10;

FIG. 13 is a longitudinal section through another muffler embodying the invention;

FIG. 19 is an end view from the inlet end of the muffler of FIG. 1s;

FIGS. 20 and 21 are cross sections taken along the lines 20-20 and 21-21 of FIG. 18;

FIG. 22 is a longitudinall section through another mufller embodying the invention;

FIG. 23 is an end elevation taken at the inlet end of the muffler;

F IG. 24 is `an end elevation taken at the outlet .side of the mufiler; and

FIGS. 25 and 26 are cross sections taken along the lines 25-25 and 26-26 of FIG. 22.

`Considering first the muier 1 that is shown in FIGS. 1-5, there is a casing 3 of oval cross sectional form constructed in accordance with known practice so .that inter,- nal baffles or partitions can be spot welded to it. Itis provided with a head 5 at the inlet end and a head v7 at the outlet end, both heads being interlocked as shownat 9 with the ends ofthe casing 3. An inlet bushing 11is expanded as shown at 13 into a tight contact with the outwardly turned ilange or neck 15 on the head 5 so that the fbushing 11 can be properly spot welded to the neck after the head and internal parts have been assembled with the casing 3. The head 7 has an outwardly rturned neck or flange 17 in which is fitted an outlet bushing 19 that is eX- panded diametrically into contact with the neck 17 as shown at 21 so that the bushing 19 can be spot welded to the flange 17 after the head and internal parts have been assembled tothe casing 3. Gas t0 be. silenced flows from the engine through a suitable exhaust line into the inlet bushing 11 and passes through the various gas silencing apparatus within the casing 3 and out through the bushing y19 to the tail pipe of the exhaust system.

The central part of the apparatus within the mufiler 1 is a subassembly 23 whi-ch can be manufactured as a unit and inserted in the muffler, the various other partsbeing assembled later on from both ends of the muler and then the heads 5 and 7 attached 4by interlocking at 9 to the casing after which the bushings 11 and 19 are expanded at 13 and 21, respectively, into contact with the necks 15 and 17 and spot welded in place, The subassembly 23 is supported by the parallel transverse partitions 25 and 27. These have flanges 25a and 27a that run parallel to the inside surface of the casing 3 and which are turned outwardly so that they can :be spotwelded to the .casing 3 by suitable spot welding apparatus including inner and outer electrodes that are radially aligned inside and outside of the casing, the outwardly turned flanges permitting such apparatus to be inserted inside the casing in proper position. The partition 25 has three outwardly turned flanges or necks 29, 30, and 31 which are aligned, respectively, with the outwardly lturned flanges or necks on partition 27 that vare designated by reference numbers 32, 33, and 34 respectively. Spotwelded in position to the necks 29 and 32 is an intermediate tube 35 having louvers 37 formed therein along the surface which are of the type shown in FIGS. 4 and 5 so that they can direct gas circumferentially around the outside of the tube 35. Mounted in and spot welded to the necks 30 and 33 is an outlet tube 39 and this projects some distance beyond the end of the partition 27 as shown at 41. Mounted in and spot welded to the necks 31 and 34 is the inlet tube 43 and this tube has a somewhat enlarged end projecting toward the inlet end from the partition 25 as will be seen at 45. The tubes 39 and 43 each have louvers 37 of the type already mentioned. The inlet tube 43 has a pair of spit cham-bers 47 and 48 formed around it and the intermediate pass tube 35 has spit chambers 49 and 51 formed around it.

The chambers 47 and 48 as well `as the .chambers 49 and 51 are formed by pancake assemblies 53 and 55 respectively. The pancake assemblies 53 and 55 are substantially identical so that the description of one will suffice. Each assembly consists of -a pair of identical stampings or halves 52 `which are provided with flanges 57 Ithat lie in the plane of the original sheet metal from which the pancake halves were originally formed, the chamber portions being pressed or bowled yout of the flat pieces. The lianges 57 are joined together face to face as clearly seen in FIG. 3 and spot welded together so that the two halves .form a shell around the tube. The ends 59 and 61 of the halves of the pancake are formed to vsnugly fit the ,periphery or semi-periphery of the tube as is the center portion 62. These can be spot `welded to `the tubes if desired. Angularly spaced from the flanges 57, 'the halves of the pancake assemblies 53 and.

5.5 are formed with flats .as shown at 65 and one edge of the pancake -assembly is Vtrimmed so that the flange 57 is removed beyond the ldiameter of the spit chambers as will be seen Iat 67 in FIG. 3. By removing the flange 57 at the point 67 and tormingthe fiats 65 it is possible -to fit the pancakes 53 |closely, to the contour of the casing 3 and to `get `a good deal of additional space adjacent the center .outlettube 39 as is evident from FIG. 3. The pancake asseniblyfhalves are so formed that they can be considered standard parts to be used in mufller 1 or in varions other `rrnlillers 'having Ydifferent over-al1 dimensions andginterna-lspacings. The flats 65 `and the cut off outer flanges increase the flexibility in this respect because .they :reduce .the space taken up by the pancakes, enabling them to be used in mulilers where quarters are more cramped than VVin muffler 1.

It willbe seen that the partitions 25 and 27 with the tubes 35, y39 .and -43 spot Welded in the respective necks and v"in turn carrying pancake assemblies 53 and 55 can all fbe assembled as a subassembly into a spot welded integral unit. This unit 23 can then be inserted into the center portion of the casing 3 whereupon the partitions 25 and 27 can be spot welded in place to the casing and, after this, the elements to the left and to the right of the subassembly 23 can be inserted into the mufler as a part of the final assembly operation. When inserting assembly 23 I prefer to put the casing 3 in a fixture that will hold the casing in 4its proper shape and I also prefer to Outwardly are the ends of the casing so that the assembly 23 will in effect be funneled into it. These steps will eliminate difculties caused by 4having the outwardly turned flange on partitions 25 or 27 as the leading edge during insertion.

Adjacent to but spaced longitudinally toward the inlet end 5 of the muffler is a transverse partition 71 and spaced between it and the header 5 is another transverse partition 73. The partitions 71 and 73 have inwardly and outwardly turned flanges or necks 75 and 77, respectively, through which extends a connecting inlet pipe 79, with louvers 37 therein, that slidably fits within the enlarged end 45 (flared at 83) of the tube 43 (which is a part of the subassembly 23) as will be .seen atthe point 81. The outermost end of the tube 79 is spot welded at to the inner end of the inlet bushing 11. It will be seen that this arrangement provides a reinforcement for the head 5 since the bushing 11 is spot welded to the head and then to the tube 79 which in turn is spot welded to the partitions 73 and 71 by way of necks 77 and 75.

The chamber between the head 5 and the partition 73 constitutes a resonator chamber 87. The chamber 89 between the partition 71 `and the partition 25 is a crossover chamber. Connecting the cross-over cham-ber 89 with lthe resonator chamber S7 is a tuning tube 91 that is spot welded in and t-o inwardly `and outwardly turned fianges or necks 93 and 95, respectively, in the partitions 71 and 73.

At the outlet end of the lcasing 3 there is a transverse partition 97 that is spaced from the partition 27 to define therewith a cross-over chamber 99. Between the partition 97 and the head 7 is a partition 101 which like the partition 97, and the other partitions herein, has an outwardly extending ilange running around it Iby means of which it is seated in position on the inside of the casing 3 and then spot welded to the casing by radial electrodes on the inside and outside of the casing, The space between partition 97 and partition 101 constitutes a resonator chamber 103 while the space between the partition 101 and the end header 7 constitutes another resonator chamber 10S. The outlet bushing 19 fits in an outwardly turned flange or neck 107 in the partition 101 and is spot welded to it, thus typing the head 7 `to the partition 101 to reinforce the head 7. As .shown at 109, fitting inside of the end of the bushing 19 and spot welded to it is ya yconnecting tube 111 that is enlarged at its end as shown at 113 and flared so that it slip fits over the end 41 of the outlet passage tube 39, the tube 111 extending throughy the inwardly .lianged neck 115 of the partition 97 and ibeing spot welded to it. A tuning tube 117 is spot welded to inwardly and outwardly turned flanges 119 and 121 on partitions 97 and 101 and is preferably aligned with tube 43. Flanged opening 123 connects chambers 103 and 105 to form a compound resonator.

ln assembly, after unit 23 has been inserted and spot Welded in place, the partitions 71 and 97 with tubes `91, 111, and -117 already spot `welded to flanges 93, 115, and 119 are inserted and the outwardly turned partition anges spot welded to the casing by spot welding apparatus inserted through the ends of the casing. Partition 73 with tube 79 spot welded to flange 77 (and bushing 11 spot welded to tube 79) and partition 101 with bushing 19 spot welded to flange 167 are then inserted, the outwardly turned flange slipping readily over tube 91 andv the flared end of bushing 19 slipping over the end of tube 111. Then, from the inside of the casing, the outwardly turned partition flanges are spot welded to thescasing, the tubes 91 and 117 are spot welded ,to outwardly turned anges 95 and V121, and the end 109 of tube 111is spot welded to bushing 19. It may be noted that end louvers 37 will engage partition 71 to limit-the slipping of tube 79 into tube 43 and that flange 7'5 will catch under flare afigol 33 to control insertion of partition 71. lt may also 'be noted that the tubes 79 and 43 may be connected together, if desired, `in the same sort of joint as bushing 19 and tube 111, i.e., the tube 4,3 slipping inside and spot welded to the tube 79 which in turn was spot welded to flange 75, After the partitions and members have been inserted and spot welded in place, as described, the end headers 5 and 7 may be interlocked at 9 and the Ibushings 11 and 19 expanded and spot welded to flanges and 17.

In operation, gas enters the inlet bushing 11 and flows through the tube 79 into the tube 43. Some of the gas passes through the louvers37 of tube 79 into the large spit chamber 121 between partitions 71 and 73. Other lgas passes through louvers 37 of the tube 43 into the spit chambers 47 and 48, these various spit chambers acting to eliminate roughness and relatively high frequency sounds. Gas leaving the tube 43 enters the cross-over chamber 99 and passes upwardly to the intermediate flowback tube 35. Heavy notes may pass through the imperforate tube 117 into the resonator chamber 105 and this action is compounded by means o'f the langed tuning neck or opening 123 in partition 101 which connects the resonator chamber 105 in a compound relationship with the resonator chamber 103. The gas that is flowing through the tube 35 is subjected -by means of its louvers 37 to the high frequency spit chamber control of chambers 49 and 51 and ows into the cross-over chamber 89. Heavy notes still in the gas may pass through the imperforate connecting tuning neck 91 into the resonator or tuning chamber 37. The gas ows toward the outlet through the tube 39 and from louvers 37 into the spit chamber of relatively large size 125 which lies between the partitions 25 and "27. The gas liows through tube 39 into the tube 111 and Vthence into the outlet bushing 19 from which it -goes to the tail pipe and to the exhaust.

It may be noted that aligned apertures 124 in the headers and partitions are drain holes and may be formed at the bottom of all six internal partitions and preferably, for standardization, also at the tops thereof as shown. Thus, the condensate sump means in the muier, defined by the end lheaders 5, 7, the partitions 25, 27, 71, 73, 97, 101, and the bottom wall of the muffler casing, are connected by the condensate drainage holes. When all the internal partitions are provided with the drain openings 124, which are preferably about 1A diameter, water within the mutiier will iiow back and forth lengthwise of the muliler from the cool to the hot chambers as the muler rocks back and forth slightly due to movement of the vehicle in which it is mounted. This water will be vaporized 'by the hot exhaust gases and carried out by them without the need for any external drainage openings. The end chambers y87, 121, 103, and 105 tend to run cooler than the other central chambers and act as natural condensers but due to the connection of these chambers with the hotter central chambers by way of openings 124 the condensate will move to the central chambers and be evaporated, thus markedly reducing corrosion of the muffler. These features are of particular importance in dual muftlier systems as the niufllers therein tend to be cooler and thus more likely to corrode.

Turning now to the form of muffler shown in FIG. 6, this mufiier being designated by the reference number 141, it will be seen that there is found within the casing 143 of the muflier a subassembly which is identical to the subassembly 23 and which will therefore be identied by the reference number 23', no further details of structure being mentioned since it is interchangeable with the unit 23 that has already been descri-bed. At the inlet end of the muflier 141 are a pair of transverse partitions 145 and 147. The partitions have inwardly and outwardly turned necks 149 and151, respectively, through which extends an imperforate tuning neck or tube 153 which is spot welded to `both of the necks 149 and 151, being spot welded to neck 149 outside of the casing and to neck 151 inside the casing in accordance With assembly techniques discussed above. The partitions 147 and 145 also have flanged openings or necks 155 and 157 and through these extends a long inlet tube 159. The tube 159 is spot welded to the neck 157 and projects beyond the partition 14'5 as shown at 161. lt also projects a very substantial distance beyond the partition 147 toward the inlet of the mufer as shown at 163. The tube 159 may be of a lock seam construction and provided with spaced embossments whereby it is readily turned into a tubular section from a flat section and spot welded to the neck 157 on the embossrnents prior to being inserted in the casing. The tube 159 is provided with a set of louver openings similar to those previously described and shown in FIGS. 4 and 5, these being identified by reference number 167 and omitted from FIG. 6A for simplicity. The louvers 167 are located between the partitions 145 and 147 and open into the chamber defined by these partitions, this constituting a large spit chamber 169 and louvers 167a abut partition 145. Outwardly of the embossment 165 area, the tube 159 is provided with another set of similar louvers 171. Around the tube and around the set of louvers 171 is a pancake construction 173 of the same type as previously described pancakes 55 and consisting of comnlemental halves 175, as shown in FIG. 6A. The halves are flat sheet metal pieces bowled out and spot welded together around their flanges 176 to provide a spit chamber 177. The closely fitting ends 175:1 of the pancakes are spot Welded to the tube 159. One flange 176 is cut off Iush with the periphery, as before, so that it fits snug against the casing. The halves are provided with flats 174 to decrease over-all size as indicated in connection with pancakes 55.

A hanged partition 181 at the inlet end has a iianged tuning neck or opening 183 that is larger than the tube 159 and the inlet bushing 185 'which is spot welded to the tube 159 at 187.

The partition 181 also has flanged openings 189 and i 191. The space between the partitions 181 and 147 constitutes a resonator chamber 193 and the space between the partition 181 and the inlet end header 195 constitutes another resonator chamber 195 which, being in series with the chamber 193, the two chambers act as a compound resonator construction. The header 195 is assem'bled to the casing 143 after the parts already described have been inserted in accordance with principles outlined above and is interlocked as shown at 197 with the ends of the casing. The header 195 has an outwardly flanged neck 199 that is larger than the inlet bushing so after assembly the bushing 185 is expanded as shown at 201 into tight engagement with the neck 199 and then it can be spot welded to the flange or neck 199.

At the outlet end of muffler 141 there is a dished partition 203 which has a ylianged neck or opening 205 in which is spot welded imperforate tuning tube 207 prior to insertion in the casing. The space between the partition 203 and the partition 27 constitutes a cross-over chamber 209. Also spot welded to a neck 211 in the partition 203, prior to insertion in the casing, is the inlet bushing 213 and it will be seen that it slip fits over the projecting end 41 of the outlet passage tube 39. The outlet end header 215 can be placed over the bushing 213 and the periphery thereof interlocked at 197 with the end of the casing. The 'bushing 213 can then be expanded at 217 into tight contact with the neck 219 of the header 215 and spot welded to it. It will be seen that from this arrangement the inlet bushing 185 and the outlet bushing 213 both act to tie their respective headers and 215 to the internal parts of the muler and thus serve to reinforce the heads against strain or blowout.

In operation, inlet gas enters the bushing 185 from the exhaust line of the engine and passes along tube 159 into the tube 43'. As the gas passes the spit chamber 177 (in resonator chamber 193) lcertain of the high frequency sounds and roughness are removed. When vto the tuning action of chambers 259 and 261.

it passes the larger spit chamber 169 some of the lower frequency roughness and noise is removed by passage through the louvers 167. In the tube 43 the gas is subjected to the action of spit chambers 47 and 43. Gas leaving the tube 43 enters the cross-over chamber 209 and some of the lower notes may pass through the imperforate tuning neck 207 which is in alignment with the intermediate tube 43 and be subjected to the action of the resonator chamber 221 which lies between the partition 203 and the end header 215. `Gas passing through the intermediate passage 35 is subjected to the action of the spit chambers 49 and 51 and then passes into the cross-over chamber 223 between the partition 25 and the partition 145. Gas in the cross-over chamber 223 is subjected to the action of the compound resonator chamber construction 193 and 195, the gas or sound waves passing through the tube 153 into the chamber 193 and from thence it can pass through the openings 183, 191, or 189 into the chamber 195, it of course being obvious that anything entering these chambers must be reflected back to the cross-over chamber 223 through the tuning tube 153. In order to leave the crossover chamber 223 for the exhaust line, the gases `must pass through the outlet pipe 39 and in doing so theyl will be subjected to the action of the large spit chamber 125. Gas then enters the outlet bushing 213 and passes onto the tail pipe and thence to atmosphere.

FIGS. 7 and 8 show a modified form of inlet end construction for a muffler 141', similar to muiiier 141 as shown in FIG. 6, in which tuning occurs oit the inlet tube 159. lIn this arrangement there is an imperforate transverse partition 251 and a transverse partition 253 having a anged opening or slot 255, a necked large 'opening `258, and smaller openings 257 which communicate ,the chamber 259 between the partitions with the chamber 261 between the inlet header 195 and the partition 253. The partition 253 is of the particular shape that is seen best in FIG. 8. The inlet t-ube section 159 Vhas a long series of louvers 263 preferably similar to those shown in FIGS. 4 and 5, these being omitted from FIG. :8 for simplicity. Supported on and around the inlet tube 1,59 is a pancake construction 265 which consists -of the lstamped identical halves 267 and 268 formed from initially flat sheet metal. The flanges and intermediate web 269 and 271, respectively, of the halves are spot welded together to form a unitary section and the end necks 273 and 274 are spot welded to the tube in the manner that has already been discussed above in connection with the pancakes used to provide the spit chambers. The halves are formed to provide a long spit chamber 275 around the openings 263. Communicating with the spit chamber 275 is a fairly long tuning passage 277 (constituting with chamber 275 a long reverse bend passage) which leads gases from the spit chamber into the resonator chamber 259 where the gases are subjected The construction will serve in some applications to replace tuning from the cross-over chamber 223 in the mufller of FIG. 6. The flange 269 is cut oft on one side as shown at 269 to provide a snug tit to the side of the casing. The pancake 265 is supported by spot welding of the necks 273 and 274 on the tube 159 and also by spot welding of flanged slot 255 thereto at points of contact 279. Partitions 251 and 253, tube 159', and

pancake 265 may be put together as a subassembly and insertedV into the casing prior to interlocking ot head 195. Obviously the struct-ure shown in FIGS. 7 and 8 could be modified to include an inlet bushing expanded onto neck 199 and spot welded to tube 159 just as in FIG. i6, if desired.

FIG. 9 shows a .modified pancake construction 301 for the subassembly 23 or 23. In this arrangement the outlet passage 39 as well as the spit chambers 47", 4,8, 49, and 51 are all formed in the two complemental pancake stampings 303 and 305 which are spot welded together in the contacting flanges and webs 307 and 309. The spit chambers are necked down in the same manner as before to contact and be spot welded to tubes 35" and 43". The outlet passage 39 formerly provided by tubes 39 or 39 is, in this case, formed right in the halves 303 and 305. Louvers 37 for passage 39 are formed in the halves 303 and 305. It is obvious that pancake 301 can be combined with partitions 25 and 27 (or 25 and 27) to form a spot welded subsassembly 23 having the advantages and functions already described.

FlGS. 10-12 show another mulller 401 embodying the principles of this invention. This muflier has an outer shell or casing 403 consisting of a spirally wrapped double ply inner shell 402 which is interlocked at 405 to the inlet and outlet end headers 407 and 409 and around which is disposed a single layer 404 of sound deadening metal which is attached in place after the partitions have been spot welded to the double wrapped shell 402, the friction between the two layers dissipating sound energy. Disposed within the casing 403 is a tri-ow subassembly 23a which corresponds to the unit 23 that has already been described, the principal difference being that pancake spit chambers are provided around only one of the three tubes. The subassembly 23a comprises inlet and outlet side partitions 411 and 413 having three sets of aligned openings all of which are provided with outwardly eX- tending llanges 415, 417, and 419. Spot welded in the sets of ilanges are the inlet tube 421, the intermediate tube 423, and the outlet tube 425. Each of the tubes is provided with louvers, the tubes 423 and 4,25 having louvers 427 which are more or less tubular shaped while the tube 421 has louvers 429 that are shaped like the louvers 37 of FIGS. 4 and 5. Mounted on the tube 421 around the louvers 429 is a double pancake assembly 431 identical to those already described in connection with the other modifications and which provides a pair of spit chambers 433 communicating with the inlet tube 421.

Between the subassembly 23a and the inlet header 407 is a transverse partition 435 having an outwardly turned fiange whereby it may be spot welded to the casing after insertion of the subassembly 23a. The partition 435 has a central opening provided with an outwardly extending ange 437 and this is aligned with the flange 439 around the inlet in the header 407. An inlet bushing 441 extends through the outwardly `extending flange 439 and is spot welded to it. The inlet bushing is necked down at 443 and ilared at its inner end as shown at 445 so that it slidably receives the outer end of the inlet tube 421 which is spot weld-ed at assembly to it, the lange .437 and the Abushing 441 also being spot welded together at a preassembly operation (i.e. before the parts are inserted in casing 403). The partition 435 also has a tuning tube 447 spot welded to the iiange 449 of an opening therein which is aligned withtube 423, this being done prior to insertion of the partition 435 in the mutller casing. The partition 435 divides the space between partition 411 and header 407 into a resonator chamber 451 and a cross-over chamber 453.

On the outlet side of the subassembly 23a are three partitions 455, 457, and 459, all provided with outwardly extending flanges so that they may be spot welded to the casing after insertion therein. The partition 455 has an opening aligned with the outlet tube 425 and provided with an inwardly extending flange 461 to which is spot welded the outlet tube 463. The outlet tube 463 is also spot welded in a neck 465 `formed in the outlet header 409 and it slidably ts in a flanged opening 466 in partition 457 and extends through an enlarged opening 467 in the .partition 459. The tube 463 is enlarged -at its inner end and flared to slidably fit over the end of the tube 425 at assembly, the outwardly ared end engaging the ange 419 to control the location and insertion of the tube 463.

amiable g Aligned with the inlet tube 421 is a tuning tube 468 that is spot welded at a pre-assembly operation to the flange 469 in partition 455 and after assembly to the outwardly turned flange 470 of partition 457, the outer end of the tube 468 terminating in but being spaced from the flanged edges of an opening 471 in the partition 459. The partitions 455, 457, and 459 define with the partition 413 and the outlet header 409, a series of chambers which in FIGURE l() are from left to right as follows: a cross-over chamber 472, a large spit chamber 473, a resonator chamber 474, and a resonator chamber 475 which is compounded with the resonator chamber 474 through the openings 467 and 471 in the partition 459 as well as by a flange-d opening 476 in partition 459 (the hanged openings in the partition 459 acting as tuning necks). Louvers 477, similar to louvers 37, in the tube 463 open into the spit chamber 473.

The opposite sides of the muftler casing 403 may, in the region of chambers 451 and475, be provided with inwardly extending embossments or beads 478 to prevent flutter of the side walls and the inlet bushing 441 may have a pair of indentations 479 formed therein on opposite sides as stops for the pipes to Ibe inserted therein.

In operation of the mufer 401, gases `enter the inlet bushing 441 and pass through the tube 421 where some of the high frequency sounds are silenced in spit chambers 433. Some of the gas passes through the tube 465 where lower notes are silenced in the resonator chambers 474 and 475 but this gas must return through the tube 468 and with gas from the outlet of tube 421, enter cross-over chamber 472 and reverse its direction to pass through tube 423 wherein additional silencing is accomplished by communication through louvers 427 with thelarge spit chamber 430 between the partitions 411 and 413, some back pressure reducing cross bleeding occurring from tube 423 to outlet tube 425 through chamber 480. Gas leaving the tube 423 enters cross-over chamber 453 and communicates through tuning tube 447 with a resonator chamber 451 -where further low notes may be removed. From cross-over chamber 443 gas passes rearwardly through tube 425 and out of the mufler through the bushing 465 after additional silencing in spit chambers 480 and 473 takes place through communication with these chambers by way of louvers 427 and 477. Y

To permit condensed water to ow to the relatively hot chambers 472, 453, and 480, the six partitions in the muiller 401 are provided with small (14 diameter) drain holes at their midplane at the top and bottom thereof as seen at 481 in FIG. l2, the inlet and outlet headers 407 and 409, however, being imperforate. This arrangement provides for internal drainage of water that accumulates inside the casing 403 so that the hot gases passing through the mufller will evaporate the water and pick up the resulting vapor and carry it out of the muffler.

FIGS. 13-17 show another modified form of muler 501 using a tri-llow subassembly 23b similar to the assemblies already described. This mufller has a casing 503 to the opposite ends of which are interlocked, after insertion of all the inner parts, the inlet and outlet headers 504 and 505, respectively. This subassembly 2311 comprises the inlet side partition 506 and the outlet side partition 507 each of which have outwardly turned peripheral llanges whereby they may be spot welded in place in the casing 503 after insertion. The partitions 506 and 507 have sets of aligned holes provided with outwardly extending anges as shown at 508 and 509 to which are spot welded the inlet tube 510 and the return flow tube 511, respectively. The tubes 510 and 511 have rows of louvers 512, 513 formed therein opening into the chamber 514 between partitions 506 and 507. The partition 506 has a central opening provided with an outwardly turned flange 515 to which is spot welded the end f an outlet tube 516. The outlet tube 516 has three sets of louvers 517, 518, and 519 all of which are similar to louvers 37; The louvers 518 and 519 are encased by a pancake subassembly 520 of the type already described in detail which forms small volume spit chambers 521 and 522 around the outlet tube, the louvers 517 opening directly into the relatively large volume chamber 514. The pancake 520 projects through the double diameter neck 523 formed in partition 507 and which has a shape best seen in FIG. 17, the `flat sides of the pancake being parallel to at sides of the opening.

On the inlet side of the subassembly 23b are two partitions 524 and 525 each of which has an outwardly turned ange so that it may -be spot welded to the casing 503 after it has been inserted therein. The partition 525 has an inwardly extending flange 526 around an opening that is aligned with the outlet tube 516 and to which is spot welded the inner end of a tuning tube 527 prior to insertion of the partition 525 in the casing. The outer end of the tube 527 is supported on and spot welded at assembly to the flange 528 in the partition 524. The partition 525 also has an inwardly turned ange 529 around an opening that is aligned with the inlet tube 510 and to this flange is spot welded, prior to assembly, an inlet tube 530. The 4tube 530 is necked down at 531 and ared at its inner end so that it can readily slide over the projecting end of the tube 510. The tube 530 is provided with two sets of louvers 532, similar to louvers 37, and these open into spit chambers 533 provided around the tube 530 by the pancake assembly 534 of the type already described. The outer end of the tube 530 extends through a tuning neck 535 of larger diameter than the tube and over its outer end is slipped the end of the inlet bushing 536 which is spot welded to the tube 530 on the outside of the header 504 as indicated at 537, the bushing 536 having been spot welded to an inwardly flanged neck 538 on the head 504 at a pre-assembly operation. The partitions 524 and 525 act with the inlet header 504 and the partition 506 to define the chambers 540 and 541 which act as a compound resonator chamber connected by tube 527 with the cross-over chamber 542. Another tuning neck 543 is formed in partition 524 to act with the neck 535 to intercommunicate the chambers 540 and 541.

At the outlet side of the subassembly 231) is a partition 544 with an outwardly turned flange so that it may be spot welded to .the casing after insertion therein. This has an opening aligned with the outlet tube provided with an outwardly extending flange 545 in which are seated the embossments 546 formed on the outlet tube 516 and which embossments are spot welded to the llange 545 at assembly. The outer end of the outlet tube 516 is enlarged as seen at 547 and spot welded to the outlet neck 54S formed integrally in the outlet header 505. The partition 544 acts with the outlet header 505 to provide a spit chamber 549 that communicates with the outlet tube 516 through louvers 550, similar to louvers 37, in the outlet tube. It acts with the partition 507 to detine a cross-over chamber 551 connecting the inlet tube 510 and the intermediate tube 511.

In operation, exhaust gas enters the inlet bushing 536 and passes through the inlet tube 530 wherein certain high frequency noises and roughness are removed by the spit chambers 533. 'In passing through the inlet tube 510 additional noise is removed in the large spit chamber 514 by passage through louvers 512. The gas leaving tube 510 enters cross-over chamber 551 and reverses direction to pass through tube 511 back toward the inlet of the muler. During passage through tube 511 certain noise and roughness is removed in chamber 514 by communication therewith through louvers 513. Gas leaving the tube 511 enters the cross-over chamber 542 and reverses direction to enter the outlet tube 516. The gas in the cross-over chamber 542 and the outlet tube communicates with the compound resonator provided by chambers 540 and 541 through the tube 527, which is aligned with the outlet tube 516, so that heavy notes or low frequencies will be removed. Gas passing through the tube 516 passes by the louvers 517 which connects the gas with chamber 514. High frequencies and roughness still remaining in the gas are removed in spit chambers 521 and 522 and linally in spit chamber 549.

It will be noted that the gas in cross-over chamber 551 can communicate through a tuning neck 523 with the chamber 514 so that this chamber acts to some extent as a tuning chamber to remove tones or notes by virtue of this connection and as a spit chamber to remove roughness and noise by virtue of communication with the three tubes through louvers 512, 513, and 517. It will also be seen that cross bleeding from tubes 510 and 511 and chamber 551 to louvers 517 in outlet tube 516 will lower back pressure.

Drain holes on opposite sides of each of the live interior partitions are provided as shovm at 552 and these will give internal or inter-chamber drainage via the hot gases as already explained. Additionally a very small hole 553 (/l-la" diameter, preferably 3%,2 diameter) may be provided in the outlet header on the bottom side of the muffler to provide for external drainage, this hole being so small that it does not affect the acoustic characteristics of the chambers within the muiller, especially the chamber 549 (te. acoustically the mufer shell is substantially imperforate) but at the same time being large enough to permit water to leak out of the muffler when the mufer is cold and there are no hot gases to evaporate the Water.

Another modied form of mufer 601 is shown in FIGS. 18-21 in which a tri-flow type subassembly is preassembled and inserted as a unit into the casing 603 prior to closing of the ends of the casing by interlocking the inlet and outlet headers 605 and 606 to the ends of the casing as shown at 607. The subassembly 23C includes an inlet side partition 608 and an outlet side partition 609. The partition 608 has three openings formed therein for the support of tubes, the flanges around these openings being designated by the reference numerals 610,

Y 611, and 612, respectively. The partition 608 also has a series of relatively large and non-restrictive openings 613 formed therein. The partition 609 has three anged openings to support tubes which are aligned respectively with the flanges 610, 611, and 612, these annular flanges being designated by the reference numerals 614, 615, and 616, respectively. Supported in and spot welded to the anges 610 and 614 prior to insertion ofthe subassembly 23c is an inlet tube section 617; spot welded to anges 612 and 616 is an intermediate tube 618; and spot welded to the llanges 611 and 615 is a combination tuning tube and outlet tube 619. The tubes 617 and 618 have louvers 620, similar to louvers 37, formed therein and these are covered by pancake units 621 similar to those already descirbed but which provide single spit chambers 622 around the tubes. The tube 619 has relatively large and unrestricted openings 623 formed in the rear portion thereof, the front portion being imperforate.

On the inlet side of the subassembly 23C are the partitions 624 and 625 each of which have outwardly extending peripheral flanges so that it may be spot welded to the casing after insertion therein. The partition 625 has three openings formed therein delined by the flanges 626, 627, and 628. Spot welded to these flanges prior to insertion ofthe partition 625 into the casing 603 are the short tuning tube 629, the long tuning tube 630, and an expanded tube 631, all of these tubes projecting to some extent beyond the outlet side of the partition 625 and the tube 630 being adapted to slide within the flared enlarged end 632 of the tube 619 and the tube 631 being flared and adapted to slide over the end of the tube 617 when the partition 625 is inserted in place in the housing 603. The partition 624 has an outwardly extending flange 633 around an opening that slips over the tube 630 when the partition 624 is inserted in the casing after which the tlange 633 is spot welded to the tube 636. Prior to such in- J2 sertion the tube 629 is spot welded adjacent its outer end as shown at 634 to the tube 636. The partition 624 also has a necked opening 635 which slips over tube 631 when the partition is put into the casing 603.

Within the tube 631 is an inlet tube 636 which is illustrated as being of the same diameter as the tube 617 and aligned with it. It will be observed that the tube636 has louvers 637 formed in it and these may be similar to louvers 37 already described. However, the outer diameter across the louvers 637 is no greater and preferably slightly less than the enlarged outer end section 638 of the tube 636 which slides within a portion 639 of tube 631 and is spot welded to such portion. The tube 631 is expanded at 640 opposite the louver 637 to provide a spit chamber 641 surrounding the tube 363 and coextensive with the louver 637. The inner end of the tube 631 is necked down at 642 to fit in the annular llange 628 and be spot welded thereto in a pre-assembly operation as previously indicated. The inner end 643 oi the tube 636 has a slide tit in the portion 642 and it will be apparent that the tube 636 can be inserted at assembly through the outer end of tube 631 and spot Welded to the portion 6395. The portion 639 may be spot welded to the inner end of the inlet bushing 644, the outer portion of which is radially expanded on both sides of the hanged opening 645 in the inlet header 605 and spot welded thereto. It will be noted that the use of the expanded outer tube 631 in conjunction with the inner tube 636 provides an inexpensive method of forming a split chamber of substantial length around the inner tube and one which takes up somewhat less space than the pancake assemblies illustrated hereinbefore. It is also capable of standardization `so that it can be used in various muffler designs.

At the outlet end of the muliler 601 are the partitions 647 and 648 each with outwardly turned llanges so that they may be spot welded in place to the casing after insertion. The partition 647 has an inwardly extending flan-ge 649 defining an opening in alignment with the tube 619 and spot welded at a pre-assembly operation to the ilange 649 is an outlet tube section 650 which is necked down and flared at its inner end to slip over the end of tube 619. Over the outer end of tube 650 is slipped the inner end of a bushing 65001 which is spot welded to the llanged outlet neck 651 on the outlet header 606. The tube 650 has a series of louvers 652, similar to louvers 37, formed therein and mounted on the tube and bushing a pancake assembly 653 which provides a spit chamber 654 around the louvers. The pancake assembly 653 is similar to those already described and extends through and is supported by a hanged opening 655 in the partition 648, the shape of the opening 655 being best seen in FIG. 21. On the outlet side of the louvers 652 is mounted a restrictor member 656 in bushing 650e which consists of a reversely bent tube section, the outer portion of which is spot welded to the tube 650 at a preassernbly operation and the inner portion 657 of which -reduces the effective area of the outlet tube to serve with the tuning of resonator chambers to help silence pulses and beats.

The partition 647 has an inwardly flanged opening 661 formed therein to which is spot welded a tuning tube 662. The tube 662 extends through the outwardly extending flange 663 of an opening in the partition 648. Partition 648 also has a tuning neck 664 formed therein.

In operation of the muffler 601, `gas enters the inlet bushing 644 and passes through tube 636 where roughness and high frequency noises are removed in the split charnber 641. They are further removed during passage through tube section 617 in the spit chamber 622. On leaving the' inlet tube 617 the gases enter the cross-over chamber 671 between partitions 609 and 647. In this chamber they communicate through tuning tube 662 with a resonator chamber 673 between the outlet header 606 and the partition 643 and also through tuning neck 664 with a resonator chamber 674 between partitions 647 and 648, the chambers-674 and 673 thus acting as a comara-tabla pound resonator. Gases in cross-over chamber 671 reverse direction and pass through tube 618 wherein they are subjected to the action of the spit chamber 622. On leaving tube 618 they enter a cross-over chamber 676 between the partitions 625 and 608. Gases in the crossover chamber 676 are subjected to the action of a resonator chamber 677 between partitions 624 and 625 through the tuning neck 629 which is offset from the axis of the tube 618. kThe gases `in cross-over chamber 676 pass through the non-restrictive openings 613 into the chamber 678 between partitions 608 and 609 and from there through non-restrictive openings 623 into the tube 619 from which they can ow through tube 650 and restrictor 657 to the outside of the muiiier, being subjected to the action of spit chamber 654 on the way through the tube 650. Gases in the tubev 623 are also subjected to the action of the resonator chamber 680 between the inlet header 605 and the partition 624 by means `of the tube 630 and the front portion of the tube 619. It will be observed that by providing openings 613 in the partition 608 to get flow into the outlet tube through the volume of chamber 678, it is possible to make the tuning tube, provided by a section of tube 619 added to the tube 630, of unusually long length. This enables low frequencies to be removed in a relatively short muiiler.

FIGS. 22-26 show another form of mutiier 701 having a casing 703 with the ends interlocked at 705 with the inlet header 706 and the outlet header 707. Within the casing 763 is a subassembly 23d corresponding in most respects to the subassemblies of this type previously described. This subassembly includes an inlet side partition 708 and an outlet side partition 709, both having loutwardly turned flanges whereby they can be spot welded to the casing after insertion. The partitions 708 and 709 have aligned openings defined by flanges 710 in` which is mounted an inlet tube section 711 which is vspot welded in the subassembly to the flanges 710. The

tube 711'is provided with louvers 712 opening into the chamber 713 between the partitions 708 and 709. The

V'partition 79S has an intermediate opening dened by a vopens into a spit chamber 717 formed by the pancake assembly 718 which is similar to the pancake assemblies already described. The third unit of the pancake 'assembly extends through the inwardlyY turned neck 719 of an opening'in the partition 709, the shape of the neck 719 being best seen in FIG. 26. The outer end of the pancake assembly 718 extends into a cross-over chamber 721 `formed between the partition 709 and an imperforate partition 722 which has an outwardly turned lflange whereby it can be spot welded to the shell after insertion. Partition 722 has an annular flange 723 in which are seated Ithe Pembossments 724'that are formed on the tube 715 and which are spot welded to the flange at assembly. The tube 715 has a`set of louvers 725, similar to louvers 37, opening into the chamber 726 between the partition 722 and the outlet header 707, the

rchamber 726 thus being aspit chamber. The end of the tube 715 is spot weldedto'the inside of the drawn outlet nipple 727 on'the outleth'eader 707.

On the inlet side of the subassembly 23d are parti- .;tions 729 and 739 each having outwardly turned flanges so that they can be spot welded .to the shell after insertion. The partition 739 has a central opening defined by a flange 740 in which is spot welded a tuning tube 741 -that is somewhat larger than the outlet passage 715 but generally aligned with it, though the axes are offset from each other. The partition 7.39 also has an opening Vdened by the flange 742 in which'is spot welded at preassembly the inlet tube section 743, the end of the section 743 being necked down and flared to fit over the end of the tube 711 and abut the flange 710 as seen in FIG. 22. The tube 743 has two sets of louvers 745 which open int-o the two spit chambers 746 formed by a pancake assembly 747 of the type already described. The tube 743 extends with substantial clearance through a tuning neck 749 in the partition 729 and its outer end is supported in and spot welded to the end of an inlet bushing 751 which is expanded and spot welded to the outwardly turned flange 753 of the inlet header 706. The partition 729 has an outwardly turned flange 755 which at assembly tits. over the end of the tube 741 and is spot welded to it.

In operation of the muiler 701, gases enter the inlet bushing 751 and pass through the tube section 743 wherein high frequencies, noises, and roughness are removed in the spit chamber 746. Additional silencing is accomplished in chamber 713 as the gases go through tube section 711 and pass through louvers 712 into the chamber. Gases leaving the tube 711 enter the cross-over chamber 721 and can pass through the neck 719 or through an opening formed by an outwardly turned flange 757 into the chamber 713. Aligned with the opening 757 is a somewhat larger opening provided by an outwardly turned neck 759 in the partition 708 so that it will be seen that the return passage is provided by the volume of chamber 713 rather' than by a tube as in the previous ernbodiments. Gas leaving the chamber 713 through opening 759 enters a cross-over chamber 761 between partitions 739 and 708 and can then enter the outlet tube 715 .and be subjected therein to the action of the spit chambers 717 and 726. Low notes in the chamber 761 are subjected to the action of the tuning tube 741 which iconnects them to the compound resonator formed by the chamber 763 between header 706 and partition 729 which in turn is connected through tuning neck 765 and 749 to 74,1 will be especially effective in eliminating the otherwise exceptionally loud torque convertor powernote.

Each of the tive partitions is provided with drain holes 76.9 at kthe top and bottom thereof adjacent the casing 703 so that water can slosh from the ends of the casing to the middle as the muier is rocked back and `forth by movementV of the automobile. The water within the cooler chambers 763, 767, and 726 can thus ow to the chambers 761, 713, and 721, which are hotter due to the circulation of gases therethrough, and be vaporized to pass out of the muier through tube 715. Direct liquid drainage to atmosphere can also be accommodated by `a small hole 771 at the bottom of the outlet header which is of such a small size as not to permit gas leakage, cause spitting or hissing, or adversely atect the acoustic characteristics of the muiiier. The hole 771 is intended only to let the water leak out when the muier is cold, e.g., when the auto is stopped or just started and should preferably be no longer than lr" diameter. It could` be put in the casing wall 703 on the bottom side of the muler.

It will now be recognized that the invention provides many important improvements in the mutlier eld. Costs of manufacture are reduced by the arrangement of structure which permit subassemblies to be made up outside of the casing and then inserted as units into the casing. The various pancake designs reduce cost over presently used methods and the combination oftubes 631 and 636 (FIG. 18) is an important innovation from the standpoint of cost reduction and standardization of parts.. A very important feature which should be of great interest to the motoring public, as it will double or triple the life of a muiiier, is the provision for inter-chamber drainage whereby the cold water collecting chambers are connected through drain holes in the partitions to the hot perature thereby facilitating vaporization.

gas circulating chambers with the result that the water is vaporized as it sloshes back and forth during motion of the car and does not have an opportunity to eat out the mutiler shellor the interior parts. This action can be enhanced by use of a layer of asbestos sheet in the shell construction, such as disclosed in U.S. Patent No. 7,761,- 525 and assigned to the assignee hereof, as the asbestos wrapping will cause the muiiier to run at a higher tem- Also very important is the way the variousvparts are tied together and to the end headers of the mulilers to provide great strength that will resist blow-outs and backtires. For ex ample, three different methods of rigidly supporting the end' headers by'spot welding at a considerable distance lengthwise of the muffler away from the plane of the vibration (plane through interlocked joint, eg., 9) are shown, these methods givingy a very high resisting moment to bending at the head neck radius and eliminatingl fatigue `failures due to repeated bending. Among'other illustrations, FIG. 1 shows the expanded bushing method; FIG. 10 outlet header shows the drawn head method; and FIG. 13 inlet header shows the inner flanged header and bushing method. A further feature adding strength to the'muflier is the use of several spot welded transverse partitions, some of which may be contoured, which not only form acoustic chambers but brace the oval casings against drumming. The embossments 478 also help to prevent drumming.

From the operational standpoint, it will be noted that back pressure is at a minimum due to the relatively large gas tubes and cross-over chambers along with arrangements permitting cross-bleeding, especially cross-bleeding tothe outlet tube. The constructions are such -as to provide complete sound elimination for any given application. Several spit o r filter chambers of different volumes are provided to eliminate noise and'roughness over a frequency range from low to highand theharsh 4bark of modern high compression engines. The resonator chamber and tuning tube arrangements eliminate power notes, second harmonic beat frequencies, road load harmonics, run down noises, etc. Various yfeatures provide for high energy absorption, e.g., the large tuning tubes or the restrictor of FIG. "l8`and effective sound cancellation will -be obtained in the non-turbulent tri-ow chambers over wide speed rangesl i It will be recognized `that modifications may be made in the specific structures shown herein by way of illustration without departing from the spirit and scope yof the in- Vntion.,

l claim:

1. muffler adapted to be connected in the exhaust system of an internal lcombustion engine or the like to munie high temperature exhaust gases carrying corrosive vapors which tend yto condense and form corrosive condensate in the muffler, comprising: an elongated tubular casing having oppositely located end portions spaced along a central longitudinal axis, and header means extending transversely to the longitudinal axis of said tubular casing and closing the endportions of said Itu'bular casing, gas inlet passage means extending through one of said end header means at one end of said tubular casing, gas outlet passage means extending through the other one of said end header means at the vother end of said tubular casing, a partition means extending transversely to the longitudinal axis of said tubular casing and defining multiple chambers in said tubular casing lbetween the end header means, internal gas .passage means defining a gas `ilow path between said gas inlet passage means 4and said gas outlet passage means, mounting means rat opposite ends of said muffler for mounting said muier in a horizontal -attitude with the central longitudinal axis of said tubular casing extending horizontally, said casing having 'a bottom wall portion and extending the length of said tubular casing .through each of said chambers, said end header means .having upwardly extending end wal-l portions intersecting said bottom wall portion at the ends of said tubular casing, said gas inlet passage means and said gas outlet passage means being spaced upwardly labove and being discontinuous with said bottom wall portion, condensate sump means definedv by said bottom wall portion and said end wall portions and said partition means in said tubular casing whereby condensate in said muler collects lon and is supported by said bottom Wall portion below said gas inlet passage means yand said gas outlet passage means and is contined `within said tubular casing, said sump means lbeing'connected to said ygas outlet passage means only by said internal gas passage means along said gas flow path within said tubular casing, a portion of said internal gas passage means connecting at least one of said chambers directly to said gas inlet means whereby said one of said chambers is connected in said gas flow path lto provide a continuous ow of exhaust gases therethrough and operates at aitemperature high enough to vaporize condensate on the bottom wall lportion in said sump means in the one of said chambers, `additional portions of said internal gas passage means indirectly connecting at least one other of said chambers to said gas inlet passage means and providing a reduced flow of exh-aust gases through said other of said chambers relative to said one of said chambers whereby said other of said cham-bers operates at a temperature too low to eltectively vaporize condensate on the bottom wall portion of said sump means in said other of said chambers, and condensate passage means defined in part by said `bo-ttom wall portion and extending between said one of said chambers and said other of said chambers only along said bottom wall portion whereby condensate in said sump means on the bottom wall portion in said other of said chambers flows only along the bottom wall portion to said one of said chambers, said condensate in said one of said chambers being vaporized therein in said sump means on said bottom wall portion and being mixed therein with the exhaust gases iiowing through said one of said chambers and being removed with the exhaust gases flowing Ifrom said yone `of said y charnbers along said gas iiow path to and through said g-as out- ,letl passage means.

2. A mutller adapted `to be connected in a horizontal attitude in an exhaust system for an internal combustion engine or the like to munie high temperature exhaust gases discharged from the engine and carrying corrosive vapors which tend to condense and Iform corrosive condensate in the muti-ler, comprising: an elongated ,tubular casing having a central longitudinal axis, end Iheader means closing opposite ends of said tubular casing, -a plurality of partition means extending transversely to said longitudinal axis mounted within said tubular casing and dividing said tubular casing into a plurality of chambers, gas in-let tube means extending through one of said end header means at one end of said tubular casing and extending into said v tubular casing through atleast one of said partition means and terminating in a yiirst centrally loc-ated chamber spaced on each side from both end header means by at least one chamber, gas outlet tube means extending through the other of said end header means at the other end of said tubular casing .and extending into said tubular ycasing through at least one of said partition means and terminating in a second centrally located chamber spaced on each side from both end header means vby at leastone chamber, at least one centrally located chamber positioned 'between said irst centrally located chamber and said second centrally located chamber, gas passage means connecting said gas inlet tube means and said gas outlet tube means and defining a continuous gas iiow path between said gas inlet tube means and said gas outlet tube means, an end chamber defined by one of said end header means and one of said partition means, additional passage means connecting said continuous gas ilow pat-h to s-aid end chamber, said first centrally located chamber having a continuous iloW `of exhaust gases therethrough and operating .at a tempera- .tute .high enough to vaporize condensate therein, at least one other chamber including said end chamber having a reduced ow of exhaust gases therethrough relative to the oW of' exhaust gases through said first centrally located chamber and operating at a temperature too low to eiectively vaporize condensate in said other chamber, mounting bushing means provided on opposite ends of said muffler and connected to said gas inlet tube means and said gas outlet tube means for mounting said mulier in a horizout-al attitude Ywith the central longitudinal axis of said tubular casing extending horizontally, said tubular casing having a bottom wall portion when said muier is mounted in the horizontal attitude, said bottom wall portion extending the length of said tubular casing through each of said chambers, said end header means comprising end wall portions extending transversely upwardly from said bottomv wall portion to form condensate sump means whereat condensate in said muier collects on and is supported by said bottom wall portion between said end wall portions, said gas inlet tube means and said gas outlet tube means being spaced upwardly above and being discontinuous from said bottom Wall portion, said sump means being connected to said gas outlet tube means only 4by said gas passage means, and condensate passage means extending between said end lchamber and said first centr-ally located chamber only parallel -to and being defined in part by said bottom wall portion whereby condensate on the bottom wall portion can flow fromsaid end chamber to said first centrally located chamber for 'vaporiz-ation therein on said bottom wall portion and mixing with the exhaust gases flowing through said rst centrally located chamber when vaporized and removal with the exhaust gases flowing through said gas passage means to and through said gas outlet tube means.

3. A muiiier for receiving hot exhaust gases of an internal combustion engine carrying corrosive vapors which tend to condense and form corrosive condensate in the mutler, said muler being of the type having a casing and internal silencingstructure dividing t-he casing into a plurality of chambers, comprising inlet and outlet gas passages in said muter, a bottom wall portion formed by said casing and being located below said outlet gas passage and extending .through said chambers, transverse wall portions intersecting said bottom wal-1 portion, condensate sump means for collecting and holding condensate along said bottom wall portion between said transverse wall portions, internal gas passage means connecting said inlet and outlet gas passages and being positioned and arranged to provide a gas tlow path through the said chambers resulting in substantial temperature variations in different ones of said chambers during at least some substantial periods of use o-f said mul'her, the temperature of Iat least one of said chambers being above the vaporization Ipoint of corrosive condensate collected in said sump means in said mutller and the temperature of at least one -other of said chambers being below the vaporization point of corrosive -condensate collected in said sump means in said mufier, said sump means in said chambers being connected to said outlet gas passage only by said internal gas passage means, and corrosive condensate drainage means extending only along the bottom wall portion and connecting all of the chambers at a temperature lbelow the vaporization point of the corrosive condensate to chambers at a temperature above the vaporization point of the corrosive condensate whereby corrosive condensate in said mutiler can flow to the chambers at the temperature above the vaporization point for vap-orization therein and removal with the exhaust gases passing therethrough.

References Cited by the Examiner UNITED STATES PATENTS 984,890 2/1911 Dudderar 181-47 1,603,9110 t10/1926 Egner 181-72 X 2,018,084 10/1935 Oldberg 181-53 2,054,324 9/1936 Hollerith 181-72 X 2,070,543 2/1937 Cary et al 181-54 2,084,435 6/1937 Deremer 181-72 X 2,186,062 1/ 1940 Berg et al 181-54 2,337,299 i12/1943 Noblitt et al. 181-54 2,357,791 9/1944 Powers 181-54 2,580,564 1/1952 Ludlow 181-59 X 2,598,756 6/1952 Brightly et al. 181-49 n 2,618,354 11/1952 Hedrick 181-54 2,654,437 10/195'3 Woo-ds. 2,661,073 12/1953 Deremer 181-59 3,082,841 3/ 1963 Powers 181-54 LEO SMILOW, Primary Examiner.

ALDRIOH F. MEDBERY, Examiner. n A. S. ALPERT, ROBERT S. WARD, Assistant Examiners,

Claims (1)

1. 3. A MUFFLER FOR RECEIVING HOT EXHAUST GASES OF AN INTERNAL COMBUSTION ENGINE CARRYING CORROSIVE VAPORS WHICH TEND TO CONDENSE AND FORM CORROSIVE CONDENSATE IN THE MUFFLER, SAID MUFFLER BEING OF THE TYPE HAVING A CASING AND INTERNAL SILENCING STRUCTURE DIVIDING THE CASING INTO A PLURALITY OF CHAMBERS, COMPRISING INLET AND OUTLET GAS PASSAGES IN SAID MUFFLER, A BOTTOM WALL PORTION FORMED BY SAID CASING AND BEING LOCATED BELOW SAID OUTLET GAS PASSAGE AND EXTENDING THROUGH SAID CHAMBERS, TRANSVERSE WALL PORTIONS INTERSECTING SAID BOTTOM WALL PORTION, CONDENSATE SUMP MEANS FOR COLLECTING AND HOLDING CONDENSATE ALONG SAID BOTTOM WALL PORTION BETWEEN SAID TRANSVERSE WALL PORTIONS, INTERNAL GAS PASSAGE MEANS CONNECTING SAID INLET AND OUTLET GAS PASSAGES AND BEING POSITIONED AND ARRANGE TO PROVIDE A GAS FLOW PATH THROUGH THE SAID CHAMBERS RESULTING IN SUBSTANTIAL TEMPERATURE VARIATIONS IN DIFFERENT ONES OF SAID CHAMBERS DURING AT LEAST SOME SUBSTANTIAL PERIODS OF USE OF SAID MUFFLER, THE TEMPERATURE OF AT LEAST ONE OF SAID CHAMBERS BEING ABOVE THE VAPORIZATION POINT OF CORROSIVE CONDENSATE COLLECTED IN SAID SUMP MEANS IN SAID MUFFLER AND THE TEMPERATURE OF AT LEAST ONE OTHER OF SAID CHAMBERS BEING BELOW THE VAPORIZATION POINT OF CORROSIVE CONDENSATE COLLECTED IN SAID SUMP MEANS IN SAID MUFFLER, SAID SUMP MEANS IN SAID CHAMBERS BEING CONNECTED TO SAID OUTLET GAS PASSAGE ONLY BY SAID INTERNAL GAS PASSAGE MEANS, AND CORROSIVE CONDENSATE DRAINAGE MEANS EXTENDING ONLY ALONG THE BOTTOM WALL PORTION AND CONNECTING ALL OF THE CHAMBERS AT A TEMPERATURE BELOW THE VAPORIZATION POINT OF THE CORROSIVE CONDENSATE TO CHAMBERS AT A TEMPERATURE ABOVE THE VAPORIZATION POINT OF THE CORROSIVE CONDENSATE WHEREBY CORROSIVE CONDENSATE IN SAID MUFFLER CAN FLOW TO THE CHAMBERS AT THE TEMPERATURE ABOVE THE VAPORIZATION POINT FOR VAPORIZATION THEREIN AND REMOVAL WITH THE EXHAUST GASES PASSING THERETHROUGH.

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