US1760039A - Method of forming finned tube into shapes - Google Patents

Description

May 27, 1930. H. w. BUNDY 1,760,039

METHOD OF FORMING FINNED TUBES INTO SHAPES Filed Feb. 6, 1928 INVENToR.- r/y//L/ Haj/ F1' ff J BY f/wm y A A ToR EYS.

Patented May 27, 1 930 UNI-TED STATES PATENT' or-rflcr.

-HBBY W. BUNDY, Ol' DETROIT, IIICHIGAN, ASSIGNOR, BY MEBNE ABSIGNmTB, TO BUNDY TUBING conm, OI DETROIT, MICHIGAN, A CORPORATION OI' RICHTIG-LII' METHOD Ol' I'OBKING FINNED TUBE INTO SHAPRS Application led Iebruary 6, 1928. Serial No.l 252,222.

This invention relates to a method of forming finned tube into shapes.-

Finned tubing is advantageous for the purpose of heat exchange. Such tube can be used in heating radiators, radiators for the cooling system for internal combustion engines, and one of the later uses for such tube is for condensing units for mechanical refrigerators.

A iinned tube, however, and especially a finned tube where a helical finis sealed to the tube, or adjacent convolutions thereof sealed together, as by means of ealing metal such as so der, does not possess good bending uahties, but offers material resistance to eing bent or :formed into suitable shapes for the purpose of being used in heat exchanging units.

Accordingly, the present invention contemplates a method by means of which finned tubing can bev easily and nicely formed into any desired shape and then set in this shape. The invention contemplates the making up of a finned tube b leaving the parts thereon unscaled or not ound to ether, and while in this condition the .tube 1s shaped as desired and then the parts are sealed. By sealing the -tube at this time the tube per se 1s completed and also it is set into the shape into which it was previously formed.

lu the accompanying drawings: Y

Fig. 1 is a side elevation of a coiled finned tube showing one shape in which the finned tube may be formed .for use in a condenser unit for a mechanical refrigerator.

Fig. 2 is a view partly in side elevation and partly in section showin one form of iinned tube which can be treate in accordance with this invention.

Fig. 3 is a diagrammatical view illustrating one manner in which previously shaped tube can be subjected to a bath of sealing metal.

Fig. 4 is a view illustrating another shape into which the tube may be bent.

Fig. 5 is a view partly in side elevation and partly in section illustrating another kind of tube which can be used in following the method.

One form of finned tube which may be sirable shape to fit the needs to which it is to be put. It may be shaped into the form of a spiral coil, as shown inv Fig. 1; itmay have a circular shape, as indicated in Fig. 3;

vor it may have a U-shape as illustrated in Fig. 4. Any one of a multiplicity of shapes caii be used. The tube is quite easily shaped duc to the fact that the adjacent convolutionsV are not sealed together. After the length of finned tube is shaped as desired, it is then subjected to a bath of sealing metal such as solder. This may be accomplished by dipping the tube into molten metal 4 contained in a tank 5. When the tube is bent into relatively simple shapes, as illustrated in Figs. 3 and 4, it can be held by hand during the dlpping. Where, however, more complicated shapes are desired, which may involve relatively sharp curves, suitable guide devices or braces of any desirable character can be used. i

'When the shaped tube is thus subjected to the bath of sealing metal, it will be noted that two things are accomplished. One is the completion ofthe tube per se; in orderY to make a tube constructed as shown in Fig. 2 fluid' tight, the overlapping convolutions must needs be sealed together. It is well understood by those versed in the art that molten sealing metal finds its way in between the overlapping parts. The other thing accomplished is, the shaped tube is given a set. In other words, after the tube has been subjected toits bath of sealing metal and then removed, the finned tube retains its shape upon the cooling of the sealing metal.

Preferably, when the length of shaped tube is thus dipped, the tube is somewhat longer than necessary so as to provide portions which extend out from the bath by means of which the shaped tube can be handled. These ortions can be cut of and' then part of the he ical fin removed adjacentl the end to permit of attaching of suitable fixtures thereto.

Another kind of tube which can be shaped in accordance with this invention, is shown in Fig. 5 wherein a preformed tubular body 6 is used and upon which is wound linl stock an gular in section, one leg of the angle forming a helical fin 7 and the other forming a helical band 8 lying directly on the preformed tube..

This tube can be nlcel bent and shaped before the helical fin stoc is sealed `to the tubular body, and it ,has been found that such a tube can be bent into a curve sharper than can the tube 6 without the helical 1in, because the helical iin stock reinforces the tube and prevents the same from collapsing or buckling in a sharp angle where the curve is effected. Moreover, as set forth in my copending application Serial No. 205,593, filed July 14, 1927, .the inner tube 6 can be made of relativel light stock inasmuch as the iin stock afordys a material reinforcement therefor. Such a tube is capable of being shaped as desired and then subjected to a bath of sealing metal in a manner as above described.

By way of example, two forms of finned tube construction have been shown, but it is within the invention to utilize finned tube differently constructed; thus, the overlapped or helical windings of Fig. 2 need not be sufficient to rovide a double wall such as shown, but may just suflicient to provide overlapping surfaces for securing purposes. Moreover, the helical stock on the tube shown in Fig. 5 need not be wound so close together, but the several convolutions thereof may be spaced apart.

Claims:

1. The method of forming finned tube into.

shapes and inishin the tube which comprises, forming the ned tube and leaving the parts unsealed, forming the tube substantially into the desired shape and then subjecting the same to a bath of sealing metal to finish the tube by sealn the parts together and to set the tube into t e shape in which it was formed.

2. The method of forming finned tube into shapes, which comprises making a tube hav ing a fin composed of helically wound stock, shaping the tube into the desired shape before the hehcal windings of the fin are sealed to the tube, and then settinthe tube and sealn the fin winding by su jecting the shape tube to a bath of sealing metal.

3. The method of forming finned tube into shapes, which comprises'making a tube having a iin composed of helically wound stock, shaping the tube into the desired shape before the helical windings of the lin are sealed to the tube and while the tube can be easily thus shaped, and then dipping the shaped tube into a bath of molten sealn metal to set it into said shape and seal win ings to the tube.

4. The method of forming finned tube into shapes which comprises making a tube having a iin composed of helically wound stock, sha ing the tube into the desired shape before the ehcal windings of the iin are sealed to the tube and while the tube can be easily thus shaped, dipping the shaped tube into a bath of molten sealing metal and then allowing the sealn metal to harden toset the tube into the said shape and finish the tube by sealing adjacent parts together. v

5. The method of formin finned tube into shapes, which comprises ma 'ng a finned tube which includes a tubular bod fin thereon at least one o f w ich is'formed by helically wound strip stock, leaving parts of the finned tube unconnected, shaping a length of this finned tube into the desired shape, and then subjecting the same while in such shape to a bath of molten sealn metal to seal the' fin to the tubular bod an to set the length of inned tube into t e shape in which it was formed.

6. In the art of forming heat exchange devices or the like out of finned tubin the method comprising the taking of a tu ular body with a helica fin thereonand bending the same substantiall to the shape of the device to be formed be ore the fin is ixedly secured to the tubular body, whereby relative sliding movement between the tubular body and the helical fin may take place so that the finned tubular body vmay be readily formed into curves or the like without rupture, and then after the device has been thus formed, fixedly securin the helical fin and the tubular body together y molten sealing metal.

7. In the art of formingv heat exchange devices or the like out of finned tubin the method comprisin the taking of a tu ular body with a helica fin thereon and bendingA the same substantially to the shape of the device to be formed before the iin is lixedly secured to the tubular bod whereby relative movement between the tu ular body and the helical lin may take place so that the finned tubular body may be readily formed into curves or the like without rupture, and then after the device has thus been formed, tixedly securing the helical fin and the tubular body together by dipping the formed device while it is retained in its form, in a bath of molten sealing metal.

8. In the art of forming heat exchange devices on the like out of finned tubin wherein the tubing consists of a tubular bo y and the fin is footed'so that the foot portion lies next adjacent a tubular body and coo erates to form a strengthened tubular wall, t e method comprising the taking of this finned tube and bending it substantially into the shape of the device to be formed before the tubular and a 'helical' body and the iin are fixedly secured together, whereby relative movement may take place so that the finned tubular construction may be readily formed in curves or the like witl1- out rupture and then after the tubular construction has been thus formed, fixing the fin and tubular body portion together and setting the tubular construction into the shape in which it has been formed by molten sealing metal.

9. In the art of forming heat exchange devices or the like out of finned tubing wherein a tube is utilized having wound around its exterior surface fin stock L-shaped in cross section with one leg of the L abutting against the tube, the method comprising the taking of this finned tube construction and bending the same substantially into the shape of the device to be formed before the tube body and iin are Iixedly secured together, whereby relative sliding movement between the tube body and iin may take place so that the finned tube may be readily formed into curves or the like, without rupture, and then securing the tube and fin together and settin the same into its formed shape by the application thereto of a molten sealing metal.

In testimony whereof I aiiix my signature.

HARRY W. BUNDY.

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