US2251074A - Method of making heat exchanger fins - Google Patents

Description

July 29, 1941.

F. J.- SIBLEY METHOD oF MAKING HEAT EXCHAGER yFINS Filed Jan.. ,19.r l1939 2 Sheets-Sheet 1 1N VENTOR.

l l I B-Y 3: lll-LAM ATTORNEY.

July 29, 1941. F. J. slBLr-:Y

METHOD OF MAKING HEAT EXCHANGER FNS 2 sheets-sheet 2 Filed Jan. 19, 1939 INVENTQR FyoyoJf//ey.

BrDDALLv/v ATTORNEY Patented V.July 29, 1941Y ml'rnon or' Maxlvglmr lixcrlslrcilitltA Floyd J. Sibley, Detroit, Mich. j Application January 19, 1939, serialNo. 251,665

s claims. '(cl. ias-151.3)

My invention relates to an improved heat exchanger n and a methodv for making and for applying the same. My improved heat exchangernn is disclosed andv claimed in my divisional `patent application Serial No. 277,213 led June 3,

' It. is an object of my invention toprovidean improved heat exchanger' iin having superior thermal conductive characteristics and com-prisinga heat conductive metal vane, a heat conductivemetal base flange, andthe vane and the base flange being joined integrally through a junction which is thicker than either the base ange or the vane extending therefrom.

It is also an object of my invention to provide such a heat conductive iin in which the vane and Y the base flange of the n taper thinnerextending away from the thick junction in angular relation whereby the maximum amount of metal in a cross section of the iin is provided in the junction where. it is useful for improving both the meextending from the base is serrated to provide a plurality of vanes integra1`with the base flange and presenting an increasedalr contacting sur-l face -as the vanes are separated by applying the base ilange in close contacting engagement on a tube or other curved surface. V

Another object of my invention is to provide a method for making my improved heat exchanger iin from an elongated element or bar of suitably ductile metal which consists in simultaneously are to be made.

cutting and thrustingthe metal from one side ofthe element to form a raised flange on one face ment being cut or chiselled at regular intervalsv before the operation of shaving the n from the deformed face'of the element or bar. l

It is alsoan object of my invention to provide a method for simultaneously making a serrated heatexchanger un and a finned tube construction in" which the base ilange of the iin lis simultaneously wound tightly around a tube to be ilnned with suiilcient tension to secure it tightly on theA tube while aiding in the operation of drawing the shavedvnfrom'the bar. y

The invention itself, however, both as to the shape and construction of my heat exchanger filil and as to the method of making and applying' the iin, together with additional objects and advantages thereof, will best be understood from the following description when read in conjunction with the drawings, in which:

Fig. 1 is a plan view showing one form and arrangement of means suitable for making my heat exchanger fin from a bar of metal;

Figs. 2 and 3 .are side elevational and end elevational views thereof respectively;

Fig. 4 is a cross sectional view of a tube showing how the serrated n is applied thereon;

' Fig. 5 is a longitudinal sectional view of a nned tube showing the improved heat exchanger iin installed;

Fig. 6 is a cross sectional view of the heat exchanger n, per se, showing the improved conformation thereof:

Fig. 7 is a perspective view showing a portion of the elongated bar as it appears after it has been swaged to form the base flange rising from one side which has been chiselled or cut at regular intervals prior to the operation of shaving the iin from 'the bar, and

Fig. 8 is a plan view, 'partly diagrammatic showing how my apparatus may be disposed for continuously working a circular bar.

A Referring more particularly to Figs. 1, 2 and 3 Aof the drawings, suitable means for making my improved heat exchanger iin .comprises an element Yi of any suitable metal from which the ns For this purpose a metal is selected such as copper, or'aluminum or any other metal having `suitable characteristics of thermal conductivity, ductility, corrosion resistance and the like according to the use for'which the ilns are to be used, as will be readily underan elongated element perferably in the form of a bar f rectangular cross section, either straigh one face of the lbar by cutting and pushing-up the metal from one side. 'This may be 'accom-f pllshed by various tools sliding, or reciprocating as will be readily understood, but for this purpose I und it convenient to utilize a cylindrical thrust- A ing roller 3 having. a sharp square corner 5,

shown in Fig. 3, which acts as a cutting edge. The sharp corner t maybe other than a right angle if desired depending upon the angular relation desired between the angularly disposed portions of the heat exchanger iin.- A cylindrical guide roller 'I of smaller diameter extends down axially from the thrusting roller 3. and both are rotatably journalled on a shaft 9 supported vertically from the lower'end of a bracket Il, which may be a part of a rigid cast frame I3. 'I'he frame i3 also serves to provide a suitable guide face I5 for `one side of the metal bar I while the other side of the bar is `forced against the thrusting roller` 3. `The lower portion of the guide frame I3 is provided with a suitable channel I5 to receive a dovetail I'I projecting from an adjustable guide I9 which is moveably mounted for slidably supporting the bottom face of the bar I as itpasses the thrusting roller. A pair of adjusting shafts 2i are journalled at the lower ends in a pedestal ange 23 projecting from the bottom of the frame I3, and theupper ends of the shafts are threaded for adjustably entering threaded apertures 25 in the lower side of the movable guide i9. A hand wheel 21 is provided on each adjusting shaft for elevating the guide I9 as the upper face of the stock bar I is cut down.

As the bar I is moved along, a cutting or chisel roll 2li forcefully engages the upper face of the bar for cutting the metal thereof to provide transversely disposed cuts 28 at equally spaced points between the ange 2 formed by the thrusting roller t and the other side of the bar. For this purpose the chiselling roller 21 is provided with a plurality of chisel edges 3l which extend across the face of the roller. As shown in Fig. 3, the face of the chiselling roller 27 is slightly tapered and the chiselling edges 3l thereon are so disposed that they out deeper into the face of the bar adjacent the flange 2 than at the opposite side. Also a tapered annular face surface 29 onV the side of the chisel roller 2l serves to shape the tapered side of the flange 2 pushed by the thrusting roll 3.

The chisel roll 2li is journalled on a horizontalV shaft-33 projecting from the rigid frame I3 and disposed transversely over the bar I. As shown,

the axes of rotation of the thrusting roller 3 and the chisel roll fil lie in a plane so that the forming of the ange 2 on the bar, and the chiselling of the surface at any particular point on the upper face is performed at the saine time. As will be understood, this precise arrangement is not necessary, and the chiselling roller 21 may be so disposed with reference to the thrusting roller 3 that any particular portion of the upper face of the bar is chiselled either before or after it has been swaged to form the flange 2 instead of simultaneously, and the question of the time sequence of the two operations does not arise because both operations are being performed continuously as the bar passes along. The chisellingl roller 21 may also be entirely omitted when itls desired to make heat exchanger fins having vanes which are solid or unserrated as in making straight fins for mounting on a at surface as for nning the side walls of tanks and the like.

'Ihe completed'heat exchanger fin 30 is shaved off from the upper face ofthe bar I after` this surface has been worked to form the raised flange 2. For this operation a sharp shaver 31, of suitable hardened tool steel, is secured by a bolt 39 on the upper face of the frame I3 where it is rigidly supported by suitable interlocking means, such as a pin l I, to prevent rotation. The

the approaching bar I in a position to have the cutting edge substantially on a level with the lower edges of the chisel points 3|, as shown in Figs. 2 and` 3 in order to shave a cut of 'a proper depth. As the bar I is moved toward the shaver 3l the flange 2 is shaved from the upper face of the bar and sufficient joined metal is shaved from the upper face of the bar with the flange to provide a vane, or a plurality of vanes 36, extending therefrom. The shaver 31 may be clamped on a wedge or shim 4I to facilitate adjusting its position correctly, and it is suitably positioned forv cutting through the ybar substantially along a position represented by the dotted line 43 shown in Fig. 7.

To apply the fin on a tube l5, the tube is rotatably mounted adjacent the side of the bar and slightly inclined from vertical, as shown in Fig. 2. For this purpose the lower end of the tube 45 fmay be firmly gripped in any suitable chuck 4l which is firmly secured on the upper end of a threaded `shaft 49. The threaded shaft 49 is supported through a threaded bracket 5I secured on the side of the frame I3 by bolts 53. The shaft 49 is rotated with suitable force to hold the iin taut and wind it firmlyV on the tube 45 as it is shaved from the bar I. The ends of the fin may be secured to the tube in any' suitable manner as by soldering or brazing. For rotating the shaft dt, a handle E5 may be pivotally journalled on the lower end of the shaft for driving the shaft through a pawl wheel 51 and ratchet 59, although any power driven means may be provided for this purpose as will be understood.

To force the stock bar I along, any suitable work feed means may be utilized such for example as feed rollers BI and 63 journalled be tween brackets $5, as shown in Fig. 2^. One of the rollers 6I is ,provided with a worm wheel G1 which is forcefully driven by a worm 69 rotated by a convenient hand wheel 'II on an extended shaft i3. The lower roller 63 is journalled in end bearing blocks 'I5 which slide in slots 'I'I in the end bracket 65, and a threaded shaft 'i9 extends ,down therefrom to a hand wheel I for adjusting the position of the lower roller as the bar is shaved thin. Turning the hand Wheel il in the proper direction, the stock bar I may be drawn past the thrusting roller 3, the chisel roll shaver is disposed with the sharp edge 4d vtoward 75 2l, and the shaver 31 to form and separate the iin therefrom.- Similarly work feeding means or rolls may be disposed at the rear for pushing the bar I, and if desired any suitable power means may be provided for moving the ba I and for rotating the shaft 49 to windV the fin on the tube, as will be readily understood.

To make heat exchanger fins in -accordance with my method, an upstanding flange 2 is formed or raised on the upper face of an elongated bar I of suitable metal. As previously explained,`this may be accomplished by passing the bar I firmly against the sharp edge 5 of a thrusting roller 3 which cuts and thrusts the metal up from one side of the bar in an operation sometimes referred to as swaging. This may be accomplished Ain a series of steps if desired. Also either simultaneously, or before, or after forming the upstanding flange 2, the upper face of the bar is provided with cuts 28 extending transversely from the position of flange 2 to the other side of the bar at regular intervals. The bar then ap- ,pears as shown in Fig. 7. The flanged face of lswirling of the air therebetween retards the circulation of the air4 and stirs or'scrubs the air of heat exchanger varis integral with the ange and extending angularly therefrom. The end of Y the serrated iin is attached to a tube t be nned,

in any suitable manner as by soldering or brazing, Y

and the tube is rotated with suillcient force to draw the iin taut to aid in separating it` from the' bar and to ilx the fin firmly in helical relation on the tube, as shown in Figs.l 4 and 5.

When a straight bar I'is used, the bar is" preferably reversed end-for-end each time'it isY passed through the rollers in order to work the upper face of the bar down equally from both sides, because the operation tends to remove more metal from one side. My method of making iin into more intimate contact withv the metallic surfaces.

It is not .my intention to'iiniit my invention to the precise steps.. herein described nor to the particular meansl vor the specific-materials referred to, since these are referred to merely as the preferred arrangement in my heat exchanger iin and the method 'for making it. It will be understood that the present disclosure is illustrative merely, the invention comprehending all variations thereof.

I claim:

1. The method of making a flanged heat exchanger nn from a bar of ductile metal which consists in, setting a sharp' edged tool slightly below and slanting into apart of the face of length. vWhen the stock -bar is Worked con-- tinuously, two machines are preferably provided for working the bar in series relation and keeping the upper surfacev level by pushing vup the flanges from opposite sides of the bar, as shown. Either straight or serrated heat exchanger fln may be made by omitting or performing the stepof chiselling or cutting the surface ofthe bar at regular intervals as described. My improved heat exchanger iin 30 comprising the base or mounting flange 2 and the heat absorbing or emitting vane or vanes 36, formed as previously described, has improved Vheat conducting properties and operates very eiciently to transmit heat between the base ange and the vane. As shown in Fig. 6, the shape of the iin the bar and progressively cutting and-thrusting to upset some metal to form a projection thereon, and shaving oil the projection with sufcient 'metal from thesurface to form a ilanged 1in having an integral junction thicker than either changer n from a vbar of ductile metal which -l consists in, setting the sharp edge of a tool slightly belowand moving it intoa face of the bar projection withsuilicient metal off of the face in cross section is such that the heat emitting vane extends angularly from one edge 'of the base flange joining integrally therewith through' a junction which is substantially thicker than a rounded inner corner.

of the-bar from the projection toward the other side of the bar to form a -ilanged iin having an integral junction thicker' than either the flange or the n and having a sharp outer corner and 3. The method of making a heat exchanger n from an elongated bar of ductile metal which either the base flange or the vane. By angularly is meantl any angle to distinguish from parallel. i As Vvirili be seen, the vane and the base flange taper thinner toward the outer edgesto save metal where it is not useful. Also the shape of the fin so formed is such that the outer corner 83 of the junction is a sharp edge or corner and the inner corner is a curve 85 providing extra and rigid mechanical support. VThe sharpv outer consists in, cuttingand thrusting the metal from one side of the bar to form-a raisedflange on t regninr intervals from the aange position to the other side of the bar, and shaving the ilanged face off ofthe bar in such a manner as to recorner 83 also makes the lower surface of the base ange 2 completely contact the surface to be finnedl with a close flrmly abutting engagement providing a large contact area, and also bringing the heat conductive vane close to the surface which -is to be ilnned for rigid support and eicient thermal contact on the nned surface. Furthermore, a heat exchanger fin made in accordance with my method has good solid metal which is free from checks in the junction between the base flange and the vaneand this provides superior thermal conductive properties.

movev the flange with suflicient metal from the bar to form a plurality of vanes extending integrally therefrom.

4. The method of making a heat exchangeriln from an elongated bar of ductile metal which consists in, cutting and thrusting the metal from thereof, cutting said faceof the bar transversely coupling with the air, or' other gas or vapor, bey cause a greater contacting area is provided in the crevices between the vanes, and-the eddying or one side of the bar to form -a raised flange onl one face of the liar, cutting the face of the bar' at regular intervals from the ilange position to the other side of the bar, shaving the-flanged face on of the bar in sucha manner as to remove the flange with sulcient metal from the bar to form a plurality of vanes extending integrally therefrom, winding the separated end of the ange upon a tube to be ilnned, and rotating the tube with sumcient force to hold `the separated iin taut and apply the iin firmly upon the tube.

5. The method of making a heat exchanger iin from an elongated bar of ductile metal in the form of a circle or cylinder forcontinuous operation which consists in, forming an upstanding flange on onefa-ce of the bar by swaging or cutting and pushing the metal up from one side at substantiallyregular intervals from the position of said flange to the other side ofthe bar, shaving the ilanged face of! ot the bar in such a manner as to Aremove the flange therefrom with sufficient metal to forn a vane extending lntegrally from one edge of the ange, and perv.forming said flange forming, chlselling and shaving operations continuously around the cylindrical bar.

6. The method of making heat exchanger fin as set forth in claim 5, except that said operations are performed continuously at two differ- FLOYD J. SIBLEY.

Images