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Publication numberUS3850018 A
Publication typeGrant
Publication dateNov 26, 1974
Filing dateSep 24, 1973
Priority dateSep 24, 1973
Publication numberUS 3850018 A, US 3850018A, US-A-3850018, US3850018 A, US3850018A
InventorsS Drosnin
Original AssigneeS Drosnin
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Radiator fin-tube construction and method
US 3850018 A
Abstract
A thin ribbon of core material passes through apparatus to form fin-tube radiator core material. A first pair of power-driven rolls forms "louvers" extending in a pattern transversely of the ribbon, with a gap between the louver patterns, and fine rectangular holes extending in a second pattern at the gap. The holes are formed by transverse alternately male and female combs inset in the first rolls. The holes rigidify the ribbon at the middle of the gap to resist tendency to fold or curve. The ribbon then passes through a pair of second rolls of star-shaped cross-section having slower peripheral speed than the first rolls. This arrangement causes the ribbon to fold at each gap with a flat center portion formed with the holes and bends to either side of the center portion. A third set of rolls beyond the second set has rubber-like rings which create an adjustable drag on the ribbon and complete formation of the folded ribbon with right angle bends at the folds. In the core, the flat center portions abut the radiator tubes and have a substantial area of heat-transferance contact therewith. The solder on the tubes, when heated, flows by capillary action through the holes and when cooled forms heads which secure the fins in place.
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Description  (OCR text may contain errors)

Primary Examiner-Lowell A. Larson Attorney, Agent, or FirmJulian Caplan Unite States Patent 1 1 1111 3,850,018

Drosnin Nov. 26, 1974 RADIATOR FIN-TUBE CONSTRUCTION AND METHOD [57] ABSTRACT [76] Inventor: Sidney s. Drosnin, 2087 10th Ave., A thm rlbbon f re material passes through appara- San Francisco Calif, 941 16 tus to form fin-tube radiator core material. A first pair of power-driven rolls forms louvers" extending in a Fllfidi p 4 1973 pattern transversely of the ribbon,. with a gap between [21] APPL 399,683 the louver patterns, and fine rectangular holes extending in a second pattern at the gap. The holes are formed by transverse alternately male and female U-s- Clombs inset in the first rolls The holes the rib- [5 n t bon at the of the gap to resist tendency to Fleld 0f Search o curve The ribbon then passes through a pair of ec- 113/113 ond rolls of star-shaped cross section having slower peripheral speed than the first rolls. This arrangement [56] References Cited causes the ribbon to fold at each gap with a flat center UNITED STATES PATENTS portion formed with the holes and bends to either side- 544,1s0 8/1895 Lewis 72/186 of the Center P A third Set of rolls beyond the 1 717,049 12 1902 stokes second set has rubber-like rings which create an ad- 1,546,195 7/1925 Briskin justable drag on the ribbon and complete formation of 1,927,791 9/ a e the folded ribbon with right angle bends at the folds. 2,250,593 7/1941 M65961 In the core, the flat center portions abut the radiator 33671161 2/1968 Avaklanmtubes and have a substantial area of heat-transferance 3:53; 72/187 contact therewith. The solder on the tubes, when 3:766:873 10/1973 Narog "I:...........IIIQIIIII..- 72/186 heated flows by capnary actlo through the holes and when cooled forms heads which secure the fins in place.

, 6 Claims, 11 Drawing Figures RADIATOR FIN-TUBE CONSTRUCTION AND METHOD This application is an improvement on my US. Pat. No. 3,693,710.

This invention relates to a new and improved folded fin construction for radiators wherein a ribbon of thin sheet metal such as copper is formed in patterns of louvers with gaps between the louvers and with preferably rectangular perforations in a second pattern centered in the gap between the louvers, the ribbon being folded back and forth upon itself with the fold located to either side of the second pattern of holes so that there is a relatively flat perforated surface between the folds which abutts a radiator tube. The flat surface provided greater heat conducting contact between the tin material and the tube. Further, solder on the outside surface of the tube, when suitably heated, flows by capillary action into the perforations and upon cooling forms heads similar to rivet head which produce a better bond between the fin and tube.

A feature of the invention is the forming of the socalled second pattern of holes along the middle of the gap between the louvers on the ribbon. In addition to forming the perforations required for bonding, the rectangular perforations provide rigidity so that when the ribbon is folded there are substantially right angle bends on either side of the pattern of holes and the area where the holes occur is relatively flat, all for the purpose heretofore described.

Still another object of the invention is to provide a radiator core structure consisting of tubes and fins with improved heat transferance from the tubes to the fins and a more secure bond between the fins and the tubes, so that in the use of the radiator the bond will withstand repeated and extreme pressure and temperature variatlons.

Another feature of the invention is the provision of apparatus hereinafter described in detail for fabricating the fin stock rapidly and efficiently without danger of the ribbon of stock being ruptured and without danger of the folds being improperly formed.

A still further object of the invention is to provide a method whereby the louvers and holes are formed in the arrangement heretofore described as the ribbon of metal is fed through first stand rollers and then to slow down the advance of the ribbons so that the folds form initially at the flat portions of the ribbon, the degree of folding increasing until the flat surfaces are fabricated as has heretofore been described.

Other objects of the present invention will become apparent upon reading the following specification and referring to the accompanying drawings in which similar characters of reference represent corresponding parts in each of the several views.

In the drawings:

FIG. I is a top plan view of the apparatus of the present invention being partially broken away to reveal parts of the machine below the upper level thereof.

FIG. 2 is a vertical sectional view taken substantially along the line 2-2 of FIG. 1.

. FIG. 3 is an enlarged fragmentary sectional view through the first stand rollers. 1

FIG. 4 is a transverse sectional view through one of the rollers.

FIG. 5 is a view taken substantially along the line 5-5 of FIG. 3.

FIG. 6 is a view taken substantially along the line 6-6 of FIG. 5.

FIG. 7 is a side elevational view of a portion of the structure of FIG. 2 in enlarged scale.

Fig. 8 is a side elevational view through an automobile radiator formed in accordance with the present invention.

FIG. 9 is a fragmentary sectional view taken substantially along the line 9-9 of FIG. 8.

FIG. 10 is a fragmentary sectional view taken substantially along the line 10-10 of FIG. 8.

FIG. 11 is a greatly enlarged sectional view of a portion of the structure of FIG. 10 showing the contact between the fin structure and a tube and the solder bond between the same.

Directing attention first to the apparatus best shown in FIGS. 1-7, a base plate 21 is provided extending substantially the entire length of the machine to which various vertical and horizontal members are attached by means of machine screws. Proceeding from top to bottom, as viewed in FIGS. 1 and 2, first roll stand 22 feeds the ribbon of sheet metal from top to bottom and perforates the same. Said stand 22 is mounted on front and rear vertical guides 23 which are attached to base plate 21 by any suitable means. Between the guides 23 is a bottom rest 24 likewise fastened to plate 21 and extending vertically upwardly to about the line of feed of the ribon 106. At the top, the guides 23 are interconnected by longitudinal connectors 26.- Rotatably mounted in stand 22 are top and bottom shafts 27, 28 each having at either end a bushing 29. Bushings 29 are received in top and bottom bushing holders 31 provided with inner and outer ears 32 so that the shafts 27, 28 are vertically movable in the gap between the guides 23 and a flat on the bottom of the lower holder 31 rests on the top of rest 24. To accommodate different thicknesses of sheet metal stock with which the apparatus is used, interchangeable spacers 36 are positioned between the holders 31 governing the distance between the shafts 27, 28.'To apply the requisite pressure to hold the shafts in position a hold-down or pressure screw 37 is theaded through connector 26 and has a spring 38 bearing against the top of upper holder 31. Shafts 27, 28 rotate together and carry at their outer ends gears 33. A lateral extension of upper shaft 27 comprises a drive shaft 34 which is driven by an electric motor and gear reduction box (not shown). The same motor drives the entire apparatus.

Each shaft 27, 28 carries an end collar 39 immediately inward of bushing 29 and between the end collars 39 are die collars 41, here shown as three in number. Formed on the exterior of collars 41 are louver dies 42' which cut and bend the sheet metal stock into the louvers in a pattern. It will be understood that one of the louver dies is male and 'one female and that these are staggered. Formed in collars 41 are radial slots 43. Fitting in slots 43 between the end collars 39 are male combs 44 alternating with female combs 46. The combs 44, 46 are held in place by retainer screws 47 which are threaded into one of the collars 39 and have points bearing against the ends of the combs. The combs are thus locked in position. The male combs have male teeth 48 and the female combs female teeth 49, as best shown in FIGS. 4 and 6. These perforate the sheet metal stock in rectangular preforations which extend lengthwise of the direction of movement of the ribbon.

At the intake side of the first stand 22 (i.e., to the top as viewed in FIGS. 1 and 2) is a ribbon guide extension 51 on either side of the machine and fastened to the rearward guide 23. The extensions 51 are interconnected by a cross rod 52 and carry ribbon side edge guides 53 which are spaced apart along rod 52 the exact distance of the ribbon being fed and are so located that the ribbon is fed between the appropriate collars 41. It will be understood that ribbons of different widths are used depending upon the customers demand and that by-and-large a single set of rollers at the first stand will accommodate a wide variety of different ribbon widths and patterns.

immediately to the left of first stand 22, as viewed in FIGS. 1 and 2, are top hold-down plate 56 having a forward edge 57 and a bottom hold-down plate 56a. The plates 56, 56a are horizontal and are spaced apart about the width of the material making up the ribbon after it has been perforated. The forward edge 57 of top plate 56 is spaced rearwardly of second roll stand 61; and, as hereinafter explained, by reason of the gap between the edge 57 and the stand 61 the initial folds in the ribbon stock occur in this gap.

Second roll stand 61 is formed with front and rear guides 62 on either side bolted to base plate 21 and is further provided with a bottom rest 63 intermediate guides 62. At the top, longitudinal connector 64 bolted to the top of the guides 62 holds the parts in alignment. Stand 61 has vertically aligned transverse top and bottom shafts 66, 67 each provided at each end with a bushing 68. Each bushing is received in a bushing holder 69 having projecting inner and outer/forward and rear ears 71 which bridge the guides 62 so that the shafts 66, 67 may move vertically between guides 62 and the downward movement is limited by rest 63. Pressure adjustment screw 72 threaded through connector 74 engages the upper bushing holder 69 and determines the vertical position thereof. Shafts 66, 67 carry at at least one outer end gear 73 and one of the gears 73 is connected by means of idler gear 74 to one of the gears 33 so that the shafts 27, 28 and 66, 67 turn synchronously. Each shaft 66, 67 is formed with splines which provide top and bottom stars 76, 77 each having a plurality of radial arms 78. The number of arms 78 is fewer than the number of combs 44, 46 (i.e., vs 12) and the diameter of the stars is considerably less than that of the combs 44, 46. Hence the peripheral speed of the teeth on the combs 44, 46 is greater than the peripheral speed of the arms 78. As is best shown in FIG. 2, the centerlines of stars 76, 77 are spaced apart so that there is no intermeshing similar to that of gears. The function of the arms 78 is primarily to engage the ribbon of sheet metal as it enters the second stand 61 and retard its movement relative to the movement imparted by the first stand. Since there is a gap forwardly of edge 57, the result is that the ribbon of material folds, forming initial folds 111 which are less than right angle and later forming right angle folds. The second function of stars 76, 77 is to insure that the material is fed properly beyond the second stand.

Third roll stand 81 has top and bottom side plates 82, 82a-on either side of the machine which support opposite ends of transverse horizontal veritcally aligned top and bottom shafts 84, 83. Each bottom side plate 82a is bolted to forward guide 62 of the second stand. On either side is a horizontal extension 98 bolted to forward guide 62 and which carries the top slide plate 82. v

There is a vertical slot (not shown) in the side guide 62 where extension 98 is attached to provide for vertical adjustment. Bottom shaft 83 at either end is journaled in side plate 82a. Top shaft 83 at either end carries an eccentric bushing 86 which is rotatably journaled in side plate 82. Adjustment screw 87 threaded into side plate 82 bears against bushing 86, and by turning screw 87 the vertical position of shaft 84 may be adjusted. Horizontal bottom plate 88 formed with openings 89 underlies shaft 83 and is secured to base plate 21. Horizontal top plate 91 is bolted to plates 82 and is disposed below shaft 84 and is spaced above plate 88 a variable distance depending upon the material being formed. Top plate 91 has rearward extending combs 92 which are interposed between shafts 83, 84 and prevent the material being handled from wrapping around the shafts.

Side edge guides 93 are adjustably positioned on rod 95 supported by extensions 98. Guides 93 hold the material aligned. Also supported on extensions 98 is cross tie 96 from which top hold-down plate 94 extends forwardly to adjacent shafts 83, 84.

The periphery of each shaft 83, 84 carries a plurality of rubber or rubber-like rings 97 which are fixed in such manner as to fit in the spaces where there are no perforations 108 or louvers 107 formed on the ribbon 106 being handled. The shafts 83, 84 are not power driven. The rubber rings 97 create a frictional resistance to movement of the stock through the machine and insure that the stock is folded in a manner hereinafter described.

Forward of third stand 81 is a cut-off stand 101 which contains a blade actuated by cylinder 102 to cut the stock into required length. The details of cut-off stand 101 are conventional and are not herein described in detail.

As is explained in my US. Pat. No. 3,693,7l0, and particularly referring to FIG. 8 of the drawings of said patent, an alternative form of apparatus, which is standard in radiator fin rolling equipment, employs modifled star wheels 42, 43 in which the means for forming perforations are installed. As will be readily understood by one skilled in the art, the pins 47 of said prior patent may be replaced with male combs 44 of the present invention and the recesses 48 of said prior patent may be replaced with the female combs 46 of the present invention. The louver-forming dies 42 of the present invention may be installed on the flanks of the stars of said prior patent star wheels. Such alternate star wheels may be incorporated in the present invention in the first stand of the apparatus, replacing the rollers replacing the dies 42 and combs 44 and 46 and the collars 41. The ribbon stock 106 is fed from such first stand between the plates 56, 56a and into the second stand. The principle of operation of the modified apparatus is essentially the same as has been described with reference to FIGS. 1-7 of the accompanying drawings.

Directing attention now to the method of the present invention, a thin ribbon 106 is provided, the width of the ribbon and its thickness depending upon the specifications of the radiator to be formed. A preferred material of construction of ribbon 106 is copper, since it is heat conductive and easily worked and also has an affinity for solder. The ribbon 106 is fed from top to bottom as viewed in FIGS. 1 and 2, and the speed is controlled by the speed of rotation of shafts 27, 28. As the ribbon 106 is fed through the first stand, two operations are performed thereon. Louvers 107 are cut and outwardly bent by the louver dies 42 which are formed on the periphery of the diecollars 41. The die collars 42 are formed with gaps there-between, and in the center of each gap are combs 44, 46 which cooperate to form in the ribbon 106 holes 108 which are rectangular, having their longer dimension in the direction of feed of the ribbon 106. The cutting of the holes 108, as best shown in FIGS. 3, 5 and 6, forms cusps 109 which rigidify the material around the holes 108, thereby providing resistance to bending. As the ribbon approaches the second stand, because the second stand has a lower peripheral speed than the first stand, incipient folds 111 of less than 90 are formed in the ribbon. After passing through the second stand, the ribbon is further retarded by the third stand and this causes the ribbon to assume a shape, as best shown in FIG. 11, wherein the area between the louvers 107 is formed with right angle folds 112 and flats 113 between the right angle folds which are at right angles to the portion of the ribbon carrying the louvers 107. An important difference between the ribbon of the present invention and that of the prior US. Pat. No. 3,693,710 is that instead of being rounded, the areas 113 between the louvered portions are flat and at right angles.

A conventional radiator core is shown in FIG. 8 having pluralities of tubes 116 preferably of oblong shape with rounded corners between which the fins are interposed. Directing attention again to FIG. 11, the flat portion 113 is flat against the side of tube 116 so that heat transferance is at a maximum. Ordinarily, the tubes 116 are coated with solder and after the fins are in place against the tubes 116, the assembly is heated in a furnace so that the solder melts. The cusps 109 surrounding the holes 118 assist the capillary action, drawing a portion of the solder 117 from the side of the tube 116 through the hole 108 and beyond. When the assembly is cooled by removal from the furnace, heads 118 of solder formaround the cusps 109 and securely lock the fins relative to the tubes 116. Severe heat and pressure conditions exist in modern radiators and the formation of the heads 118 resist breakage which might otherwise occur under the stress conditions.

What is claimed is:

1. Apparatus for forming radiator fin stock from a thin ribbon of sheet metal comprising a frame, a first stand having an upper rotary member and a lower rotary member rotatably mounted in said frame in vertical alignment, means for rotating said rotary members together, said rotary members having mating louver forming dies and transverse mating combs, alternate combs formed with pluralities of male and female teeth, said teeth shaped to form rectangular holes in said ribbon as it is advanced by said rotary members said dies and combs positioned in said rotary members to form on said ribbon longitudinally elongated louvers separated by short gaps and rectangular holes in said gaps, there being narrow areas at said gaps between said holes and said louvers, a second stand comprising at least one star-shaped roll rotating synchronously with said rotary members and hold down plates between said stands, one said plate terminating spaced from said second stand, said star-shaped roll positioned to be engaged by said ribbon and having a peripheral speed less than that of said rotary members to reduce the linear speed of said ribbon and cause the ribbon to form incipient folds at said narrow areas as said ribbon travels from said rotary members to said star-shaped roll; and a third stand having means to form said ribbon into a shape with parallel first panels each formed with louvers and flat short second panels containing said holes, said flat panels perpendicular to said first panels.

2. Apparatus according to claim 1 in which each said rotary member is a roller, said dies formed on said rol ler and said dies separated by peripheral transverse arcuate spaces between adjacent dies, said combs recessed into said spaces and occupying most of said spaces with narrow areas to either side of said combs where said ribbon is formed imperforate.

3. Apparatus according to claim 2 in which each said roller comprises a shaft, a plurality of die collars on said shaft, a pair of end collars on said shaft on the outsides of said die collars, means to cause all of said collars to rotate with said shaft, said die collars formed with aligned radial slots to receive said combs, said die collars formed with alternating male: and female louver dies.

4. Apparatus according to claim 3 in which one of said collars is formed with tapped holes to receive set screws bearing against said combs to lock said combs in place in said rollers.

5. Apparatus according to claim 3 in which said frame is formed with a vertical slot and which further comprises a bushing around each said shaft, 21 bushing holder receiving each said bushing, cooperating means on each said holder and the margin of said frame on either side of said slot guiding said rotary member for movement toward and away from the opposite rotary member, and adjustable means for applying pressure to move the axes of rotation of said rotary members toward and away from each other.

6. Apparatus according to claim 5 which further comprises replaceable spacers interposed between bushing holders to limit the minimum distance between said rotary members, said spacers being of different thicknesses.

Patent Citations
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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4280352 *Aug 9, 1979Jul 28, 1981Covrad LimitedApparatus for forming corrugated sheet material
US4523500 *Apr 14, 1983Jun 18, 1985Nippondenso Co., Ltd.Method and apparatus for cutting continuous corrugated member
US5176020 *Nov 1, 1991Jan 5, 1993Nippondenso Co., Ltd.Method for manufacturing a corrugated fin and a shaping roll apparatus therefor
US5509288 *Sep 8, 1994Apr 23, 1996Nippondenso Co., Ltd.Forming roller for corrugated fin
US5819575 *Mar 31, 1997Oct 13, 1998Denso CorporationManufacturing apparatus of a corrugated fin and method of manufacturing the same
US5937519 *Mar 31, 1998Aug 17, 1999Zero CorporationMethod and assembly for manufacturing a convoluted heat exchanger core
US6354368 *Nov 13, 1998Mar 12, 2002Zexel CorporationFin for a one-piece heat exchanger and method of manufacturing the fin
US7272968 *May 1, 2006Sep 25, 2007Denso CorporationDevice for shaping corrugated fin
US8661670 *Nov 4, 2009Mar 4, 2014Emitec Gesellschaft Fuer Emissionstechnologie MbhApparatus for producing a structured metal sheet for exhaust gas treatment devices
US20060254334 *May 1, 2006Nov 16, 2006Denso CorporationDevice for shaping corrugated fin
US20080295556 *Nov 13, 2007Dec 4, 2008Emitec Gesellschaft Fur Emissionstechnologie MbhControlled Metal Foil Production Process, Apparatus for Performing the Production Process, and Metal Foil
US20100043516 *Feb 25, 2010Emitec Gesellschaft Fur Emissionstechnologie MbhApparatus for producing a structured metal sheet for exhaust gas treatment devices
WO2000063631A2 *Apr 18, 2000Oct 26, 2000Peerless Of AmericaCorrugated fin and method of making
Classifications
U.S. Classification72/186, 72/187
International ClassificationB21D13/04, B21D53/08
Cooperative ClassificationB21D13/04, B21D53/025, B21D53/08
European ClassificationB21D53/02A2, B21D13/04, B21D53/08