US2269839A - Method of forming metallic articles - Google Patents

Description

. I I Q 4 Jan. 13, 1942. L. A. YOUNG 2,269,839

v METHOD OF FORMING METAIJQIC ARTICLES I Filed 06;. 22, ,1938 s Sheets-Sheet 1 if i f 11v VENTOR leeward 17. 1 4 4 44 ATTO MEI s.

Jan. 13, 1942. YOUNG 2,269,839

METHOD OF FORMING METALLIC ARTICLES F-iled Oct. 22, 1958 3 SheetsSheet 2 a v v I INVENTOR ,3 1 60174114 fi. )any Jan. 13, 1942. L. A. YOUNG ,269 9 METHOD OF FORMING METALLIC ARTICLES Filed Oct. 22/1958 s sheets-sheet 3 I III/Ill E E INVENTOR 4 Patented Jan. 13, 1942 4 UNITED STATES PATENT. [OFFICE I marnon oncmzfifit e ae i I I w .LeonardA.Young, DetroiQMicb. Application October 22, 1938, No.:236,586 a 2 Claims. gel. 29-188) The present invention relates to a method of cost of the metals and at the same time impairs from the standpoint inriiproving the thermal conductivity of metallic the eiilciency of the metals a cles.-

An object of the present invention is to pro- I vide a method of increasing the thermal conductivity of metal objects in which a relatively low-cost metal having relatively poor thermal of their thermal conductivity.

stances where a metallic heat conducting sur- 1 face of relatively hig'h efliciency and at relatively In many in--' low cost is required, the cost of such metals as copper and aluminum and their alloys restricts conducting qualities is united with a relatively higher cast metal having relatively higher thermal conducting properties. 1

It is a further object of the invention to provide a'method of improving the thermal conductivity. of metal articles in which a' relatively J ductile metal is mechanically united with a relatively less ductile metal to form a laminated metal surface in which the said metals are (lisposed in adjacent and alternating strips or layers without changing the thermal conductivity chart 4 acteristics of either metal. y

Another object of the invention is to provide a method of improving the thermal conductivity of metal objects in which expansion and contrac-'- ject is required to have high efllciency of thertiont of the inetal surface due to its reaction to mal conductivity d in which high strength hea and co d is con rolled. characteristics are required. v A further object of theinvention is to pro- 25 In the preferred embodiment of the invention videa method of increasing the thermal conduchere disclosed by way of example but not of giviiaymgf metal articles in Ego: meghgnica'li limitatioriil,1 I shall gescrilze thte'aliliivengongsf apon o wo-or more me a eren lied to e forma on 0 me c o ec rom coefilcients of thermal conductivity is effected in a ferrous metal or alloy,- such for example as an economical manner to provide a single metal aosteei, cast iron, or the like, and which is united surface inwhich the thermal-conducting pr p: with a more thermally conducting metal such erties of the better heat conducting metal are for example as copper an u thereof, 11; is Prefierved and the thermal expansmn and to be understood, however, that the invention is traction thereof are controlled by the action of. not limited to such metals but applies generally the less emcient thermally conducting metalh 135, the use or m metals which possess the In the formation of many objects it is desirsued strength characteristics and which meet able to provide a metallic heat conducting surrequired mt standards g "face which has high tensile and compression u I Theterm metal asusedhereinisusedinits strengths. The use 01! ferrous metals in formbroad .sense to designate uncombined metals ing such objects provides such strength charac- 4o with t m rm an teristics. However, where such objects 'areto either with as be used in fields where efllcient thermal con- P memo! ductivity is required, objects formed from .such' other (Mats n "vintages 9 this invenum ferrous metals do not possess the efilciency of Wm 9"? in the m fi objects formed from less strong but moreefli- 4s m me e being had to the cient thermal conducting metals. The more P 811 8 di -Win8 1 11 8 a D 1 1 h $1 9 ductile metals, such for example as copper-and c l wherein like "l m characters aluminum or alloys thereof, possess excellent i ghrresggnding 11:3 m s wg w 1 ewings ere own ywayo I properties of thermal conductivity but do not v have the strength characteristics frequently miii) example but; not of limitation the application. 7 of the present invention to the formation of a L quired and underpresent conditions are'more I expensive materials than are-the ferrous metals. pressure plate which may be used in the forma- Y Thealloying of such metalshaving highcoefli tion of adisk brake, clutch, or the like. cientsot-thermal conductivity to increase their 7 Fig. 1' iso plan view of a metal blank formed tensile and compressive s rengths, increasesthe 55 in accordancewith -thepresent invention fro and frequently prohibits their use.

- Examples of fields in which the present inven-; tion may be used are the'formationpi frictional I Q engaging surfaces, such for example as friction "brake and clutch constructions in which high strength characteristics are required while at the same time the metals should have a high rate of thermal conductivity; cooking and heating utensils; heat exchangerspheat transfer and radiating surfaces, such for example as furnace radiators, heating units and the like or similar devices.

20' Ingeneralwthe invention is applicable .to any fields inwhich a relativ ly low-cost metallic obblank of Fig. 1.

Fig. 3 is a diagrammatic sectional view showing being practiced or carried out in various ways.

a step in the processing of the blank shown in Fig. 1.

Fig. 4 is a cross section showing the blank of Fig. 1 after the processing operations are completed.

Fig. 5 is a plan view of a metal blank formed in accordance with a .modification of the invention shown in Figs. 1 to 4 inclusive. 1

Fig. 6 is a diagrammatic sectional view showing a step in the processing of the blank shown in Fig. 5.

Fig. 7 is a cross-sectional view showing the completed article formed from the blank shown in Fig. 5. x I

Fig. 8 is a plan view with parts broken away of a modified construction showing a blank formed of a plurality of separate segments.

Fig. 9 is a diagrammatic sectional view showing a step in the processing of the blank shown in Fig. 8.

. Fig. 10 is a plan view with parts broken away of a modified construction showing a blank formed of a plurality of separate segments. I

Fig. 11 is a diagrammatic sectional view showing a step in the processing of the blank shown in Fig. 10.

Fig. 12 is a plan view of a modified construction showing a blank formed of a plurality of separate segments.

Fig. 13 is a completed plate embodying the present inventionwhich may be formed from the blanks shown in Figs. 8, 10 and 12 respectively.

Fig. 14 is a'plan view of another modification embodying the present invention.

Fig. 15 is a cross section taken substantially on the line I 5-i5 of Fig. 14 in the direction of the arrows.

Figs. 16 and '17 arecross sections showing respectively a step in the processing of the blank shown in Figs. 14 and 15 and the completed blank at the conclusion of the processing.

Fig. 18 is a plan view showing a modified form of plate embodying the present invention.

Fig. 19 is a sectional viewtaken substantially on the line Isl-leer Fig. 1a.

Fig. 20 is a plan view of the completed plate formed from the blank shown in Figs. 18 and 19.

Fig. 21 is a sectional view taken substantially on the line 2l- -2| of Fig.20.

Fig. 22 is a plan view of a metal blank adapted to form a metal object constituting .another embodiment of the present invention.

Fig. 23 is a cross section taken substantially on the line 23-23 of Fig. 22.

Fig. 24 is a cross section corresponding to Fig. 23 but showing a further step in the manufacture of the completed plate.

Fig. 25 is a cross section taken substantially on the line 25-25 of Fig. 22.

Fig. 26 is a diagrammatic cross section illustrating the completion of a'step in the manufacture of the plate from the blankshown, in Fig. 22.

Before explaining in detail the present invention it is to be understood that the invention is not limited in its application to thedetails of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and; of

Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and-not of limitation, and it is not intended to-limit the invention claimed herein beyond the requirements of the prior art.

. Referring to the drawings, it will be seen that the present invention may be employed in a plurality of mechanical embodiments, in all of which 86 shown diagrammatically in Fig. 3.

dit

metals having different coefiicients of thermal conductivity are mechanically united in such a manner as to preserve unimpaired the conductivity of the metal having the better properties of thermal conductivity, while reinforcing and strengthening such metal by a metal having improved strength characteristics but which is a less eflicient metal from the standpoint of thermal conductivity.

In the embodiment of the invention shown in Figs. 1 to 4 inclusive, the object, such for example as a pressure plate having an annulus in the center thereof, may be formed from a blank 30 which as shown in Fig. 1 may be formed as a spirally wound piece of wire in which the separate sections are spaced as at 31 to provide an opening between the successive spirally wound layers. The wire as shown .in Fig. 2 comprises a central core 32 preferably of a ferrous metal or alloy, such for example assteel. which is covered with an outer covering 33 of a less strong but more efiicient thermally conductive material such for example as copper.

The next step in the formation of the completed article from the blank shown in Fig. 1 is There the blank 30 is placed in a female die 34 and a mating pressure exerting member 35 is placed in the die and pressures are exerted on the blank 30 to such an extent as to cause a cold iiow of the metal to form the completed article, a cross section of which is shown in Fig. 4. As there shown, the ferrous cores 32 have become rectangular in cross section and the metal 33 has formed a uniform center outward toward the edge of the plate.

Thus heat is conducted readily through the body of the piate as well as from the surface thereof. In addition, all parts coming in contact with the surfaces of the completed plate as shown in Fig. 4, will be brought in contact withthe relatively ductilecopper so that the applicationof pressures thereon to effect a frictional engagement with the surfaces of the plate is accomplished with the creation of relatively less heat of friction than where the contact is effected directly with a ferrous metal surface.

In the embodiment of the invention shown in Figs. 5. 6 and .7, I may provide a blank which is in the form of a circular ring. The ring is preferably formed from a wire such as that shown in Fig. 2, having the core 32 (Fig. 6) formed of ferrous metal such as steel, and a covering 3 of copper thereon. 1

Any suitable means may be employed for unit ing the ends of the wire, such for example. as the dovetail Joint 4| shown in Fig.5. The blank 48 is placed in a female die 42 and a mating pressure blank shown in Fig. 10, or the blank 51 shown in Fig. 12 is employed, the plate ultimately prorous core 32- has become generally rectangular I 'in cross section and is covered completely with,

the layer 33 of copper. If the ends of the wire which mate to form the joint ll are copper plated prior to the operation shown in Fig. 6, a strip of copper will appear through the body of the arduced is shown in Fig. 13and consists of a core 60 of ferrous metal and a covering 6| of copper. In addition, there are a plurality of strips 62 which extend through the metal at the points of union between the separate'segments of the met-' al used in forming the blank. Such a plate is strong enough, due to the reinforcing core 60 of ticle as s own I howeve he ends the ferrous metal, to withstand relatively high are not copper plated prior to the operation n shown in Fig. 6, the metal will-cold flow and form a mechanical union through the distortion of the sired to provide a soft relatively better thermal conducting surface at the points of frictional engagement.

If desired, a device of the present invention may be formedfrom the blank shown in Fig.

8, wherein a plurality of radial segments 48, preferably formed of round wire stock consisting of a core portion 41 formed of a ferrous metal or alloy, such for example as steel, is covered with a layer 48 of a more efficient thermal conducting metal, such for example as copper. As 'will be seen,- the formation of the blank in this manner provides a plurality of the radial segments 45 which are united along abuttin edges as for example by welding. The composite blank 45 is then processed as shown diagrammatically in Fig. 9 by being placed in a female die 49 with which a mating pressure exerting member 50 is vemployed. The member 50 is brought in contact with the blank 45 and forces the blank to take the position of the cavity in the female die. The completed article formed from such a blank is shown in Fig. 13.

In Fig. 10 is shown a further modification as to the method of forming the initial blank. Here the blank 5| is formed of a plurality of curved wirestock having an inner .core 52 formed of a.

ferrous metal or alloy such for. example as steel, and having a coating 53 of copper or similar thermally conductive metal secured thereto. Dovetail joints 54 are provided between the respective segments of the blank. As shown in Fig. 10, it is preferred that each segment of the blank be separately copperplated so that there are adjacent copper surfaces which are main- V tained in intimate contact with each other. As shown in Fig. 11, the blank 5| is placed in an opening in a female die member 55 and a mating pressure exerting member 56 is brought in contact therewith and pressures are exerted thereon which cause the metal to flow into the general shape shown in Fig. 13. Referring to Fig. 12, a blank 51 may be provided from a plurality of circumferential segments of fiat stock which has been copper plated and which are united by a plurality of dovetail joints 58. The blank 51 is similar in all respects to the blank 5| except that it is fiat in cross sec- "tion instead of circular in cross section as is the blank 5!. The blank 51 shown in Fig. 12 is .formed of a greater thickness than the thickness Whether the blank 45 shown in Fig. 8, or the compression loads. At the same time it is an efilcient'heat' conductor as thestrips of copper 52 extending through the body of the plate will carry heat through the plate and the covering 6| will carry the heat off the surface of the plate.

In the modifications of the invention shown in Figs. 14 to 25 inclusive, the stronger but less,

thermally conductive metal is utilized in the form of a single plate. and the less strong but more thermally eflicient metal is mechanically afiixed thereto.

In the embodiment of the invention shown in .Figs. 14 to 17 inclusive, the plate 10 is formed of a single piece of the stronger but less thermally efllcient metal, such for example as a ferrous metal or alloy. One surface of the plate is machined or cast to provide an outer rim'll and placed in the opening in a female die 15 and a mating pressure exerting member 16 is placed in contact therewith and pressures are exerted thereon causing the metal. blank to flow and occupy the space in the opening in the female die member 15. This will provide a completed plate as shown in cross section in Fig. 17, which is such for example as brake or clutch plates and wherein but one side of the member is brought in contact with the heat producing friction engaging element. When used in this connection, it will be found that such a plate possesses improved properties of frictional engagement and at the same time permits a rapid carrying away of the heat generated.

In the embodiment of the invention shown in Figs. 18 to 21 inclusive, I mayprovide a plate 80 which is preferably formed of a. ferrous metal or alloy such for example as stee1,'and which is provided with a spiral groove or cut 8i. As shown in Fig. 20, .the spiral groove or cut 8| is filled with a metal such for example as copper, havinga greater efficiency as a thermal conductor than the ferrous metal used in the formation of the body of the plate 80. If desired, the

, plate 80 may be formed of a greater thickness than is desired in the completed plate, in which event the plate is formed to the desired thickness under pressures as described in connection with .the foregoing embodiments of the invention.

However, in many instances such a treatment is not necessary. If desired, the completed plate may be provided with a copper plating either when in the condition of the blank shown in Fig. 18, or at the time when the copper is added thereto as shown in Fig. 20. i

The completed plate as shown in cross sectio in Fig. 21 may comprise the body portion ll formed of the ferrous metal or alloy, the covering 83 of copper, and a spiral stream 82 also of copper. It will be seen that such a plate possesses the strength characteristics of the ferrous metal or alloy used in forming the body ll, and at the same time has improved properties of thermal conductivity because of the mechanical uniting of the more thermally eificient metal therewith.

In the embodiment of the invention shown in Figs. 22 to 26 inclusive, I may provide a blank 90, preferably formed with'a series of radially extending projections 9| formed thereon. The blank 50 and the radial projections 8! are preferablyformed of a ferrous alloy such for example as steel. n the surfaces of the member 90 and in the space defined by the radial s'ectors 9|, I provide a layer 92 of copper or similar metal having a relatively high efficiency of thermal conductivity. The radially extending projections are preferably undercut in such a manner as to provide a plurality of dove-tail surfaces engaging with corresponding surfaces of the copper 92. The blank thus formed is placed in theopening in a female die member 93 and a mating pressure exerting member 94 is forced into the said opening and pressures are applied to the plate 90, causing the. plate to flow and occupy the position as shown in Fig. 26. This compressing of the plate causes a mechanical uniting of the metal 92 with the ferrous metal 9! forming the body of the plate.

In the foregoing examples shown in Figs. 14-

to 26 inclusive, I have specified the use of steel as the ferrous metal. It is to be understood that cast iron, such for example as conventional gray iron castings, may be used in place of the steel and may be subjected to the pressuresin metal surface in which the desirable physical characteristics of each of the metals are preserved.

In'the embodiments here shown the invention is applied to the formation of a disk having an annular opening therein such as may be used in fabricated metal of the present invention.

the forming die, provided, hqwever. that in such instance the metal is given a preliminary heat treatment prior to the application of pressures to effect the forming operation in the die. This heating operation can be dispensed within the instances where steel is used instead of cast iron, as steel possesses the desired properties of cold flowing which are essential to the successful formation of the plate by the methods herein disclosed.

In the foregoing embodiments of the invention several forms thereof have been shown and described, from which it will be observed that the essential characteristics of the present invention consist in the provision of a metallic heat conducting surface in which two metals having different coemcients of thermal conductivity are mechanically united to provide a composite It is to be understood that the speed with which the object will conduct heat or cold will be'determined by the relative amounts of the twometals so that if it is desirable to carry off the'thermal unitsmorerapidly, a greater amount of the more efficient heat conducting metal ,should be used than in the case where it is desired tocarry off the heat units less rapidly.

The metals arenot welded in the conventional sense but are mechanically united in such a manner that there is a surface engagement between the copperl and the ferrous metal. The two metals can be separated by the application of proper force and it will be found that the copper and the ferrous metal have been substantially unchanged as metals but have merely been deformed by the manufacturing operation.

I claim:

1. The method of producing a metallic article from a blank having relatively high strength and high thermally conductive properties, which comprises the steps of fabricating the blank from spaced sections of a ferrous metal and interposed sections of a non-ferrous, more ductile and more thermally efficient metal, and thereafter uniting said ferrous and non-ferrous metal sections of said blank by subjecting them to pressures at which the ferrous metal will cold flow whereby the said ferrous metal and said nonferrous and more ductile metal are mechanically united to form a substantially enveloping nonferrous metal urface in which veins of said nonferrous metal are interspersed through thebody of the said ferrous metal.

2. The method of producing a metallic friction disk having relatively high strength characteristics and a relatively high efliciency of thermal conductivity, which comprises the steps of cutting a ferrous metal disk-like blank to form an annular channel therein, filling said channel with copper, and thereafter simultaneously subjecting said ferrous metal blank and said copper filling to mechanical pressures sufficient to cause the ferrous metal of the blank to'coid flow and thereby to also cause the ferrous metal and copper filling to become intimately united as a unit to mechanically lock the filling in the annular channel.

LEONARDA. YOUNG.

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