[1]6 r%m 3,165,151 Ullited States Patent kimce patented Jan. 12, 1965 3,165,151 HEAT-TRANSFER TRUSSED-PADIATOR William V. Astrup and Donald W. Christensen, Racine, 'VVis., assignors to Youna Radiator Company, Racine, Wis., a cori)oration of W'isconsin 5 Filed Apr. 9, 1962, Ser. No. 186,148 2 Claims. (Cl. 165-81) This invention relates to heat exchangers of the type, generally designated "radiators," wherein the finsup- 10 ported tubes have their ends bonded to perforate dishlike headers which are spanned by trussed, channelshaped, protective and reinforcing side plates. In radiators of this kind the core is made up of a battery of parallel, closely-spaced, tubes extending through 15 and supporting closely-spaced, thin, transverse fin sheets. The ends of the tubes protrude beyond the opposite outermost fin sheets and are bonded to the perforate portions of the dish-type headers. The dish-type header, it should be explained, is one @vhere the major perforate portion 2( is a rectan.atilar-shaped depression offset by integral rims from an outwardly-extendin,-, bordering, perimetrical flange disposed in a plane parallel with that of the perforate tube-supporting portion. Generally, the tubes are made of copper or COPPcr 25 alloy and solder bonded to the headers which, as a rule, are made of brass. To provide a more rigid structure in .such a radiator it has been a practice to arran.-e steel plates on odpos@@te sides of the core. Usually, these side plates are channel-shaped and, as a rule, have had their 30 ends bonded to the headers. In the interest of greater strength, brazing is the preferable form of bonding the side plate to the headers. The solderin.- of the tube ends to the headers and the brazing of the side plates to the headers always has pre- 35 sented a problem to the manufacturers of these radiators. The problem arises from two facts: (1) soldering is done at temperatures approximately 500' F., whereas brazing is done at temperatures approximately 1200' F., and (2) it is more practical to braze the side plates to the headers 40 after the tubes htve been soldered to the headers. Hoi@- ever, stibjecting the previously, solder-bonded tubes, adjacent the header ends where the side p'iates are brazed, to the bi@her temperattir6s than reqLIred for solder bondin.- hazards the risk of melting some of the solder around 45 the tubes and weakening, if not brea-king, the tubednd bonds to the headers. To overconie this problem it recently became exped,.'- ent to interpose gussets betwzen the headers . and the side plates. Ti-,is has permitted brazing the a.ussets to th-- 50 headers before the tube ends were soldered to the headers and subseciuently soldering the side plates to the gussets at points removed from the headers. Such a stiuc1 turing of a trussed radiator is shown and described in 55 Patent NO. 2,932,489. However, even this trussed structuriig of radiators did not completely overcome the problem constantly confronting manu'Lacturers,of this type of radiator for diesel loconiotives. All too frequently, and after not-tOOex- 60 ti@nded periods of use, these radiators. Nvould develop s@rious leaks at the bonds of the tubes to the headers. Obviously, this forced the supplier to repair or replace the defective iinits. 2 Studies and tests were undertaken to try to discover the cause of these all-too-frequent defects and a possible reme. dying thereof. Two facts were apparent. These locomotive radiators are comparatively massive and are subject to tem.peratures as high as 200' F. This led to the assiamption that the expansion differential between the tubes bonded to the headers and the reinforcing side plates and the excessive vibration due to the high speeds at which these locomotives travel might be the primary causes for these recurrirg defects in the radiators. The main objects of this invention, therefore,.are to provide an improved structtiring of radiators which are subject to high-heat transfer and excessive vibration in normal use; to provid'. ai improved Lorm of floating connection of the reinforcing side plates to one of the headers to permit relative movement of the two headers as determined by the expansion characteristics of the battery of tub,es bglided to,the opposed headers; to provide an improved interfitting relationship of the nested core-protective side plates and the reinforcing side plates to reduce to a minim,,im vibration that normally tends to cause relative side-wise shifting of the finned tubes and the reinforcing side plates; to provide an improved trussed radiator of this kind comprising elemlents of such simple form ;and ease of assembly and bonding as to make for greater economy in production and longer service without repair or replacement of the Linits; and to provide a radiator of this structuring especially adapted for use in diesel@ locomotives as currently used on railroad@. In the adaptation shown in the drawings: FIG. I is a persp--ctive view of a radiator constructed in accordance with this invention; FIG. 2 is an exploded perspective of th6 tWo@ pairs of gpssets v/hich are bonded to the respective he@ders as shown in FIG. 1- FIG. 3 is an exploded perspective of portions of the several parts which assembled constitute a radiator constructed in accordan.ce Nvith this invention; and FIG. 4 is an enlarg@d, fragmentary, transverse-sectional view at one side of this improved radiator taken on the plan.- of the line 4- 4 of 'FIG. 1. The essential concept of this invention involves a rad:,ator wherein the protective side plates are @ecured al6ng the tubesupported fins and slidably nested ih @the reinforcing side @lates which have one end of 6ach bonded to@gussets in turn bonded to one of the headers and the oth-.r end of each of which is.telescopically seated in the gussets bonded to the other header so as to permit relative rnovemert of the headers under the strain bf beat cxpansion and cont,raction of the tubes and prevent relative sidewise shifting between the finned-tube core E@nd the side-reinforcing plates. he fo A radiator embodying t I regoing concept cornprises a fi-iihedttibe core 5 supported on upper and lower headers 6 and 7 which are spanned by reinforcing side plates 3 dif@rerently seated at their opposite ends in opposite pairs of gilssets 9 and 10. The hereiii-designated core 5.is a conventional unit comprisin.- a battery.,of tlibes 11 held in closely-spaced parallel assembly by a plurality of closely@spaced fin sheets 12 disposed radially @of the tubes 11 @nd having protective side plat es 13 bonded @long the opposite sides of such an assembl'y of tubes and fins. Such a structured core 5 @is shown@ and described in Patent No. 2,599,965.
[2]3,165,151 As iidicat-,d in that patelit and here the tlibes 6 are ol. elongated or substantially el'iiptical form and are arranged iii alternating staggered rows. The , protect@ve side plates 1---, i-i this adaplat;on, are formed with two longitudinally-extendin.- narrow, cha@@iiclshaped offsets 14 along an opposite and ivider med-.an oTset 15. These offsets 14 and 15 prov'de for nesting wilh the reinforcin.@ side pla'Les 8, as will be explain--d presently. The upper and lower headers 6 apd 7 are cf ideilt@-.al form wherein the major apertured portion 36. is off se i by integral end and side r;ms 17 and 18 fro,-fi a bordering flange 19 having a series of holes 20 'Lor the receptioil ol@ bolt-and-iiut fasteners (not here shown) for mounting the radiator in operative position. Obvioi-,sly, the plane of the apertured portion 16 is disposed parallel to t'@,e plane of the flange 19. It should be noted here that "upper" and "lower," strictly speaking, has reierence primarily to the position in which the radiator is shown in FIG. 1 of the dra-@vings. More often than not, when used in diesel loco-not@ves, these radiators are disposed horizontally. In that cas-the gussets would be referred to as use@d at one or the other end ol' the radiator. The reinforcing side plates 8, as lierein shown, in crosssection form simulate an E by having the base part 21 formed with a medial offset 22 disposed parallel wi'@h the perimetrical sides 23. This medial offset 22 is @ilmensioned to snugly seat in the comparable medial offset 15 in a protective side p.ate 13 between the offsets 1,1. The otisse,s 9 and 10 are of short U-shape witti the outer edg,-s of the parallel wing parts 24 disposed at in angle to the base part 26 and w;-th each witig vart 24 havin.- a@conip4ratively large circular oper,,ing 27. The lower pair af gussets 9 have @rotips of apertures 2-8 formed in the w:lngs 24 and base 26 for receivin.- kiiobs of the bonding malerial when this pair of gussets 6 are bonded to the reinforcing side plates 3, as will be explained presentilli. The pair of upper,gussets 10 do not have these series ol apertures 28, which are present in the lower pair, foi7 ,very significant rea@on that the conce@,ot for structuri.,ig the her,-in showfi radiator provides for the sldin,-,seafl-,,g of t@@l_e ends o I f the reinforcing side plates 8 in the pair of upp er gussets 10. This -is @o permit a relative u.-ires',raiied ii-loven. eht of the headers 6 and 7 toward and away from each other in response to the expansion-contraction which takes place iii the tubes,@,l Linder the.chan,-i-@ig temueratures at wh@'@ch these radiators funct;on, especially whe@i @-used for cooling @,gh-heat engines such as the diesel locomotiv@'. it has been well-known that the thermal expansion d@fferential between th@, cobi)er ori copper alloys of the tlibes 11 and the@stt@@-!,of the reinforcing side plat,-s 8, and the -gus@cts 9 and 10 w'@ien used,' is in the ra"io of 1.50 to 1.00 respectively. HoWever, heretofore, it has been ass,-,Ine@ - .that if@the reinforein@ side plates 3 were macle of heavy enoilgh material andvvere adeql,.ately bonded to the h.-aders 6 and 7 tb-is therinal expansion different-la'. could rot bl, the cause. for annoyin@ leaks that too often occurred in these rad I iators wh-.n used on dies I el locomotives. However, extended tests, antecedant to the conce,3t for 'th@ herein shown telescopic relationshin of the reinforced side-l)lates g@ and the upper pair of gussets 10, gave ample r-lason for@ believ,,ng that hov.,Tever firmly t@-e rei-tiforeir@sz side I @lates 8 I night be bbnded to the header 6 apd '7 th@- ;S I iiilrmal expar@si6n differential between these cenvenlionally used metals was, as a. matter of fact, the P-.4imary cause for the fracturing of the bonds of the ttbes l@. to the headers 6 aid/or 7 resulting in the annoying and expensive- radiator leaks. Therefore, in the@-herein-shoivn radiator, both pairs of ,gussets 9 and 10 are bonded to the end and side rims 17 and 18 of the respectine headers 6 and 7. Pfeferably t.-@i's @bonding is a @onventional braziri.- operation. TLe low@@r ends bf the reii2forcina side plates 8 are bonded to the 4. respective gussets 9. '@his is effected by a ccnver@tio,.ial soldering operation. The upper ends of the reinforcing side plates 8 are I seated ;n the upper pair of gussels 10, as the loiver ends a-@-e seated in the lower gussets 9, but the upper ends are not bonded to the g-assets .10. Thus this allowance fo@the relat;vc shifting ol the upper ends of the side plate 8 and the gussets 10 permits a relative movei-,i,-nt of the headers r, and 'I, axially of the tubes 11, d,,irin.- the alter10 nating exparsion and coiitract-lon of these tabes under the cliap-g@ng temp,-@ature conditions to which the radiator - '@s subliected inevitably. Because of the high speeds at wh;ch thesc diesel locomotives travel, it has b-,en assumed that the inevitabl@e 1- vil@-rations in the locomotive might be so communicated to the radiator as to cause some shifting of the core and the reinforcing side Diates 8 transversely of the core S. Such possible shifting, it has been assumed, mi@-ht be a contrib-atory cause to the radiator leaks. To ins,-,re 2.o against that possib'11,1,v. the reiiiforcing sid,- plates 0 and the core protective sid-- plates 13 have been l'Orineea' w-ith the hereinshown respective offsets 22 and '@14 a-i3d 15. These permit a firm iesting of these sets of side pla'Les 8 a-@id 13 as shov;n in FIG. 4. Therefore, since the rcinforc25 ing side plates 8 have been so firnily secured to the headers 6 and 7 by means of the gussets 9 and l@l, this Pestij--. of 'the opposite pairs of side plates 8 and 13 precludes any possib-le s-dtz-wide movement of the core 5 wiihin this supportin,@ iramework of th.- side p'@ates 8, tLe gassets 9 and -@O 10 and the headers 6 and 7. A ra,,i-iator, co,,.structed in accordance wi ' is invention, is assembled in t'iae follo,;ving manner: The core 5, with the tubes 11 a@.id fin s,-i-- ets 1-2, is a3- sembled in the conventional manner. The 17caders 6 a-id 35 7 and the -Ussets 9 a-,id 10, lil@ewise, are formed in the usual ma-iitier. Moreover, the gussets 9 and 10 are brazed in a convent@oria' manner at the opposite ends of the respective headers 6 and 7. The first step Ts to insert the tubes 11, at one end of 40 the cor., 5, into the anert@,ires in one of the headers 6 or 7 and solder bond tie tube end to the apertured depressed portio-- o@' the header. Next the side plates 8 have o-,lc e.-id of each ir@serted into the "lower'@' pa'@r of gussets 9 atid s-old-,red thcre'lo ip. 45 th,,- conventiona,@ i-@ianner. Then the olher header has the apertured mijor portion set ov--r the other ends of the tubes at the same time the other (i.e. "upper") e-,lds of t@,e side plates 8 ar.- instrted into the other pair, (,i.e. "upper@') .-LsseLs 10. T-nereupon, the olalier tube ends Pre sol,-Ier borded to the other beader. Variations and modifications in the details of the str-ucture and arran-ement of parts may be resorted to v,,itlii-i the sriit and covera.-e of th.- appended claims. I
