US2298348A - Formation of metal shapes - Google Patents

Description

0f 13, 1942. c. D. coxe 2,298,348

' FORMATION oF METAL sHAPEs Filed Hay, 11, 1940 4 Sheets-Sheet 2 ('/I ries D.. Cax

ATTORNEYS 0ct. 13, 19425 g, D, cox;

FORMATION OF METAL SHAPES Filed May 11. 1940 I4 Sheets-Sheet 4 INVENTOR Patented of.13,1942

2,298,348 FORMATION F METAL sHArEs Charles D. Coxe, Bridgeport, Conn., assigner to Remington Arms Company, Inc., a corporation of Delaware Application May 11, 1940, Serial N0. 334,537

(Cl. ft2-57.2)

12 Claims.

The invention relates to a method and apparatus for the making of metallic shapes directly from a molten metal, and is particularly adapted for the production of such things as metallic sheets which are relatively thin, and for the production of spherical objectssuch as balls or shot. The making of sheets has been previously accomplished in various manners.

In the manufacture of a metallic sheet or strip, one method commonly used is that of casting the metal into a relatively thick ingot and then successively rolling the ingot to the desired thickness, this being doe in a plurality of rolling operations requiring heavy and large machinery.

vIt is also necessary to reheat during the reduction v process, and much labor is required to operate the equipment. In the rolling and forging operation vin the reduction of the ingot, there is considerable loss due to scaling and waste in the ingot itself.

Another method of 'producing strip metal or sheet is by the pouring of the molten metal directly between two rotating rolls, such as in Hazelett, No. 2,058,447, the rolls being cooled and rotated as the metal is poured therebetween, these rolls generally being horizontal. Another process shown in the patent to Coxe, No. 2,183,- 010, uses four adjacent vertical rolls. In both of these types of casting directly onto the rolls,

the surface metal is solidified as contact is made with the rolls. It is evident that in such a process, much difficulty will result from unevenness'in therolls, the tendency of the metal to cling to the roll surfaces, and rapid deterioration of the'rolls due to the hot metal impinging thereon. .'lefecti've 'sheets and require expensiveequipment Y 'I'hezrnaking'ot roundv or spherical objects also heretofore has required expensive machinery or the useV of high towers for the dropping of the metal vin its molten form, which will assume a spherical' form before it reaches the bottom of the tower, such as in the conventional shot tower.

In ythe invention disclosed herein, a molten metal bath is provided, having a lower melting point than the metal to be shaped and a boiling point which is higher than the freezing point of the metal to be shaped. The metal of the molten bath and the metal to be shaped must be immiscible, or substantially immiscible, both in the liquid and solid state, and vpreferably have a different specific gravity so that they may be All these matters tend to produce` properly s eparated from each other. By im-A miscible, it is not meant that the metals absolutely are not immiscible but that the immiscibility is such that they may be yreadily separated. '.I'he metal being shaped should-also have `suiic'ient hot tenacity to hold itself together as it is v`being withdrawn.

The other objects of the invention willf'app'ear from the detailed description and drawingvsfl'ollowing, which give several forms ofthe invention and are merely for the purpose of illustration.

In the drawings:

Fig. 1 is a diagrammatic side elevation of one type of apparatus, with a portion cut away,l that may be Aused to produce metal sheets.

Fig. 2 is a detailed side elevation, partially'in section, of an apparatus similar to that of Fig. 1, but not having the cleaning rolls. l

Fig. 3 is a plan view of Fig. 2.

Fig. 4 is a cross sectional view of Fig. 2 from the line 4--4 of Fig'. 2.

Fig. 5 is a fragmentary cross sectional eleva-l tion of a modification of the molten metal bed of the apparatus shown in Fig. 1.

Fig. 6 is a fragmentary elevation of a modified apparatus for forming sheets.

Fig. 7 is a sectional elevation taken taken at lline 1-*1 Fig. 9 is a. fragmentary side elevation of a modicationof the'apparatus shown in Fig. 6;

Fig. 10A is asectional side elevation of `'a modification of an apparatus for forming sheets.

Fig.l11 is a sectional plan view of the appara# tus shown, taken on line II-H of Fig. 10.

Fig. 12 is a diagramamtic view of a modication of an apparatus for making sheets, wherein the specific gravity of the metal being shaped is greater than that of the bath.

Fig. 13 is a cross sectional side elevation of an apparatus for making individual metal shapes, such as round balls or shot.

Fig. 14 is a sectional view taken at the line ld-llof Fig. 13. l Y

Fig. 15 is a diagrammatic sectional view oi' one form of nozzle and .closure therefor, shown" Q 1whichfollows.

and the .strip ,may fbe movedorer athe -surfaceot A the molten xinnlh. causing` ymore of the pmetal ,to heele thereto. Qend thus he :along ithe lace-ofthe fbathinndthenremoved lIroxruthe'halth l ,oontinuously,orinsthe'flenth desired. 'Itllsanlso evident that stheaneiul toebe mhepedimaybe :one l `iahetihssferneuter:speciilcxrnviisyfthunshe molten *beth| :in `Jvhifch cose the molten `will j'lie on top -of molten metal to be @shaped fand the I besorexulstedges to ailowthepmpershepl r-insfoilthezzlobules ssathey pas through thez'bath.

molten ybath lisfone g ,lower memntpoint (of the metal which -is 'to and :the yspe- -ciiic gravity o! "the molten :hath may be either greater :or less than the upecliic ,gravity of the motel ato -Ahe shaped. ldepending .upon the Vxnode in lwhich the invention iscsrried out, Jas' 'will become 'npporeut in ythe :ci the invention when the molten f'xnetal to be is `poured upon audace `oi' the rnolten ebeth, Vit is lessen, except iin a. v:such as `shown ,in

1 und?, strip o! the-metal-,similar to the molten metal to .be A.shaped :be :placed ,on :the :top

aluminum will l:travel throuzh .the zba'th, ,attaining e. :spherical ionn'zhy the `time the top10! the hath, it fbcing evident, `if course. that :the y.0f :the beth must 'be made such und the kept et xsuch n point that -the .balls will ,attain their spherical i'ormb! the 1time lthey Stoel .or a melting -oi 1535' C. msybe zused in place :o i.' aluminum. its

other ,silver-.marte the molten hath toi-the und :sil- 4ver having o lov/er melting point .thanfchromium fend .nickel and e fhiaher spociiic gravity.

' Bismuth or M the molten hath `iol' imitation tot nluminum im. v Y '-f '11. for exemple. nhlnlinum 'abe :maintained at 1' a ...of :about m0 6. and most of dem kept at s mpemmxe m lrmom. soo the 120- o! .bath lso ,fas :to-contact the :molten metal to be :es it 'is poured :onto the bath, 1 lstur'tfto treese te solidgpieoe, ,I

u 110W! Aluminum 'may 'be removed nontinend ythereby giorni n Icontinuous 1:or a.

will .take place -st the interface -oi the vtwo metals, which, fin case. .will be the upper ieee oi the metal strip.v Itis also vevident that many ,cases the Vexterior ot the ymetal strip i mm :rosen fmterior might sun be in fn. :molten vor plastic iorm,'os it isilrst formed, rimtwlllbecomecompletelysolidveryshortlylaiter ii'orxnlng .or :citer :its Lremoval from the .In the formation o! spherical objects, such as shot. femolten 'bath having Ee greater speciiic metal to be :mund maybethegmolten .to `be shaped rintrobottom ol' the hath. When this is 'iL-donors nonzlefmaybesomanged thntthemolten vAsnnexnniple of twofmetals thetmnvfbe used,

aluminum will ireese zat interiace foi .theftwo metals. vThe resultant flsyer fotaluminumcan be removed. makin: gat interface fior .an-

; niuniinuxn to freeze;

strip ofthelienxthdesired.

The invention be first :described in lcon' Junction 4with `its gepplication to the manufacture ci auchv things Las Jmetal and particularly to continuous production or :metal sheets vwhiclrmo comparatively relative to ,their Referringparticulsrly .:to iris; 1. 'molten metal Atolie Qshaped is poured 3into the 2l havinrasspoutforsoutiet'21.. Aimolten metal vbeth 22 is held in ,the-,container 18. txnodiv-iicationshown infini, the'mcltenmetslgbathls n metal that `has a higher yspecific frmvitythsn the metal being `shaped and 1 flower ameltinl point. The molten lboth as previously ,described f must also have a higher boiling point athen .the melting pointoithefmeteitolbeshaped. Assn example of the means v'that :misht .he employed 4to withdrew the metal ses it lis formed over .the top of the molten hath, fthe Ytwo endless chains or engaging means 2l may be 'suitably driven 'through gears 2l Vand sha-it Il fromrsome sultebie source ,of power, the chains being Advanced in the direction'fshown Athe yarrows-in As the strip of metal reaches -theendot :theconl tainer 2-3 (Fic. (2) it `muy peas lthrough n vslot 17| und be zppedbythe roilersnndcarrled toits pointer storsseeor where itis'tobexurther `oper-- ieted upon. `Therolisll mayralsorbe soldesigned' 'ss to :ceusew'` shapingfaction pto be exerted .upon

' the sheet at this point.

As the :molten metnl flowing from the container!! .comes into fcontect `with the surface vof molten bath il, freezing ywill occur at the interface oi :the metals. tin

M portion away from ythe :interfacestlll iremainins szliquid, depending upon `the relative -diilerenoe fot temperatures between the -imths limi thicknel of the sheet to' be formed sndother factors. The

sheet .2l passes into engagement with the endless ychains 14 end hss-its `width limited thereby. land as it continues. in .its `passage :throuzh comme: it-wlumuammummlytmmhthe :withdrawn thereirom lin :the manner about :to

Iialuminumfshotor s'phericalob- -to be lthe metelmay be introduced at ithe :ci the molten leadzbath. `and the fout-its thickness. As wiilbe lexplninedlster, the rate of solidincation eii'ecis the Mtime Jof surface imposed over thesheet ,and bath by menus o! .the cover-'3l inany ofthe oonventionnlnnd'usual 7s manners: for ,example-tho inert niuuosphere muy 'be supplied through the pipo al (Fig. n and Vtop surface is the last to freeze.

vface which may then cool uniformly to present a the exit slit, such as at 32 or 21 (Fig. 2), may be made to retain the inert atmosphere within the container 30. Because the sheet being formed is oi necessity at a higher temperature than the bath, it is evident that the molten bath will ab sorb heat from' the metal being shaped, and therefore the bath must be cooled or sodesigned.. that the proper temperature differential will be maintained. This may be done in many ways, as an example thereof, the molten bath material may be drawn into the pipe 33 (Fig. 1) and passed through a suitable cooler 3l. A pump 35 may be employed to returnthe molten bath material to Athe container 23 at a temperature such that the metal sheet will properly form on the metal bath at its point of impingement therewith. Cleaning wheels, such as shown diagrammatically at 36 (Fig. 1), may be employed upon either side of the strip to clean the molten lead therefrom and any scale that may have formed before it passes between the pinch rolls 31 to the point of storage. If desired, an air blast (not shown) may be directed against the bottom of the sheet before it leaves 30 so as to remove the molten bath metal that might be clinging thereto. It is to be noted that Fig. 1 differs from Fig. 2 in that Fig. 1 has the cleaning rolls 36.

In the formation of the sheet, several means may be employed to obtain a top surface which will be either absolutely smooth or maybe easily rolled to a smooth surface. If the rate of cooling of the strip is rapid, but not quite rapid enough.

pits will be formed in the sheet similar to the sink holes in ingots; A dendritic-like structure may also form on the surface. when complete cooling takes place on the bottom, so that the One means of avoiding this is to provide a cooled roller, such as shown diagrammatically in Fig. 16 at 38, touchf ing the top surface of the metalsheet being formed. which will cause the uppersurface to freeze smoothly. the lower surface only having been frozen at the interface of the two metals.

' n there is any momen metal sun left, it win be at the interior of the sheet, and no pits will be `formed in the surface of the sheet. It is also -possible to similarly cool the upper surface of the metal by passing the inert atmosphere through a cooler and directing it over the surface ofthe metal or by other similar means. A smooth surface may also be obtained by providing a heater, such as gas flames or an electric induction heater, over the metal strip after it has been formed,- so as to liquify a layer on the upper sur smooth surface. l

In Fig. 5 vis shown' an alternative form of molten bath and cooling means therefor. which may be used instead of that shown in Figs. 1 to 4. The metal sheet 39 is supported by the relatively thin molten bath 40, which in tum is supported upon a bed 4i having cooling holes I2 running therethrough. A suitable means may be usedto force a cooling medium through holes 42.

The metal sheet may also be formed, particu- Qjlarly when it is thin, by means of the'apparatus shown in Figs. 6 to 8. In this form, the recepj :tacle for the molten metal to be shaped is at 42 and it has an opening 43, allowing the molten metal to flow out upon the surface of the molten bath. This molten bath mayV take the form shown in Fig. 1 or Fig. 5. Metal is poured into the receptacle and allowed to ilow'onto the molten bath, and drawn along the bath by any suitable the rst layer that has already been formed. It

edges 0f the Strip t0 be 0f 'rho thickness of the 'sheet oon he regulated by the feeding slot and bythe rate at which the provide a second container, such as shown at 45 of Fig. 9, and thereby form a second layer upon is evident thata different metal may be used for this purpose or the same metal. Such a method might have application in the formation of bimetallic strips for use in thermostatic devices.

Figs. 10 and 11 show still another modification of the apparatus just described which can be -used for making a metal sheet directly from the molten metal wherein the sheet being formed has a higher melting point and a lower specific gravity than ,the molten bath. A burner 46 may be employed to heat a combustion chamber 41 under the container 43, which will serve to keep the-molten bath, such as lead in 49, at the proper temperature. The metal to be formed-is introduced in the molten form through the opening 50 and will collect in the top of the chamber 5l l as at 52. In order to insure that this remains in a molten state, a fuel and air supply may be prothe junction'of the molten bath 49 and the metal it through pipe 56 to the nozzle 51.

vided at 53 to heat the metal 52. A vcirculating and cooling means for the lead is provided, having an intake 54' withdrawing the lead and'passing it through a coolerI from pipe 55 and returning Nozzle 51 is so arranged as to direct the cooled lead against the surface of the metal sheet being formed at to be shaped 52. f It is necessary in starting the o operation to introduce a small piece of the sheet already formed, to which the molten metal will cling and which can be withdrawn through the opening 58, between the rolls 59, and out ofthe bath through opening and between the rolls il. An inert atmosphere may be introduced into the container AG2 through pipe 63./ Suitable means may be employed to cool the portion of n the bath'near the sheet being moved theress into the portion e1 'uo through bythe pipe 64, withdrawing the molten metal -and passing it through a suitable cooling means. and returning the molten metal to this portion of the bath by the pipe which 4is directly over'the roll 89, serving to cool 'the-roll and to further cool the metal 'l strip, In the event that the metal to be shaped has higher specific gravity than that of the molten bath, the apparatus diagrammatically shown in y.

Fig. 12 may be'employed. In this case the molten El. The molten metal similar to that just described.

'-By the invention described herein, metal Louh-fz` iects may also be formed, such as spherical or similar objects. by the apparatus shown in Figs..

13 and 14.' The metal to be shaped may be poured into the tower 'H through a spout 72. The molten Y bath to be usedv in the forming of the objects is located at 13, wherein there is a metal having a higher specific gravity and lower melting pointthan the metal to be shaped. A nozzle may be this and to cause the uniform width.

provided at 1I through which the metal passing down the tower 1| vthrough passages 15 and 16 may be introduced at the bottom of the molten bath 11. It is to be understood that there may be more than one nozzle and that the nozzle may take various forms, sizes and shapes, in dependence upon the object that is to be produced. In the specific form shown, there is a graphite plate 18, which may be heated by suitable elecmetal; and means for effecting controlled delivery of the metal to be shaped directly to a surface of the metal of said bath.

3. In an apparatus for shaping metallic ob- -tion comprising meansv to supply the molten metal to be shaped; a substantially stationary molten metal bath container to form a planar surface molten metal bath; a molten metal bath in said container, said second molten metal being substantially immiscible with and having a jects directly from molten metal, the combina- 7c lower melting point and a higher specific gravity than the first mentioned metal; and means for effecting controlled delivery of the metal to be tricfmeans which will keep the nozzle clear and 10 shaped directly to a surface of the metal of said prevent the freezing of metal at this point. To bath. start the device, a rivet 19 or similar article may 4. In an` apparatus' for shaping composite be placed within the hole, and when a sufiicient metallic sheets directly from molten metal, the headof metal has been placed in the'tower 1l, combination comprising a container for a subthe1 rivet 19 will be forced from the hole and 1;, stantially planar surface molten metal bath; a will .allow the passage of the metal upwardly molten metal'bath in said container, said molten through themolten bath 11. It is evident that metal of the bath being substantially immiscible ',mny other means may be employed to control with and having a lo'wer melting point than the j '.thislopeningjand that this is merely an example metal of the sheet to be formed directly thereon; .ff 'a'means that might be employed. The metal 20 means for effecting controlled delivery of a Iobjlectsfwill cool at thetop of the -bath 11, such molten metal directly to a surface of the metal 'Cas ,at 80', and may be removed through the openof the bath so that freezing will occur at the "ing 8l in any suitable manner. interface of the metals; and means for effect- The metal objects thus formed ,will be spheriing a' controlled delivery of a second stream of cally shaped, and such things as metal shot may molten metalonto the at least partially frozen be so` rnade. first molten metal. `It vis also evident that the specific gravites of 5. In an apparatus for shaping metallic obthe metal to be shaped and the molten bath jects directly from molten metal, the combina- ,may be reversed and the shot dropped through tion comprising means to supply the molten the bath. Suitable apparatus for carrying out 30,1netal to be shaped; a substantially stationary this idea is shown in Fig. 17. i molten met-al bath container, a molten metal -The molten bath 11 may have suitable insulating in said container, said last mentioned molten means such as at 82 to keep the bath at a suitable metal being substantially immiscible with and temperature to allow the desired spherical shape having a lower melting point than the first mento be attained. tionedA metal; means for effecting controlled de- By the invention disclosed herein, a molten livery of the metal to be shaped directly to a r.bath having a melting point lower than that of surface of the metal of said bath; and means the metaltobe shaped and immiscible therewith for controlling the temperature of the portion may be employed in the shaping'of metal objects of the second molten metal adjacent the metal 'directly from molten metal, thus eliminating 40 to be shaped.

much of the waste'and heavy machinery used 6. In any apparatus for producing metal `vin previous methods. As this is the first time shapes directly from a molten metal, thecomthat a satisfactory method and apparatus have bination comprising a container for the metal to been developed for such a purpose, the invention be shaped; la stationary container; a molten isnot limited to the details disclosed herein, but metal bath in said stationary container, the is to be construed as broadly covering all equivametal of said bath being substantially immislent devices and processes falling within the scope cible with and having a lower melting point of the appended elaimsl 1 than the metal to be shaped; means for effectv What is claimed is: ing controlled delivery of the metal to be shaped 1. In the continuous manufacture of metal 5o directly to a surface of" the metal of said bath sheets directly from. molten metal, the process so that freezing will occur at the interface; comprising the steps of providing a bath of a supporting body associated with said bath molten metal substantially immiscible with and metal container having temperature controlling having a lower melting point and diierent passages therethrough; and means to remove specific gravity than the metal to be formed the formed metal shapes from the surface of into sheets; spreading a sheet of the molten said bath. metal into contact with the molten bath where- 7. In an apparatus for forming metalv sheets by a sheet of the molten metal to be shaped directly from molten metal, the combination will freeze at the interface of the metals; and comprising: a molten metal bath container, a then, continuously removing the frozen metal A molten metal in said container, said last mensheet from the bath. tioned molten metal being substantially immis- `2. In an apparatus for shaping metallic obcible with and having a lowerv melting point jects directly from molten metal, the combinathan the first mentioned metal; means to feed sion comprising means to supply the molten asheet of the molten metal to be shaped into metal to be shaped; a substantially stationary contact with the' molten metal bath so that molten metal bath container to form a planar freezing will occur at the interface of the two surface molten metal bath; a molten metal in metals; means to move the at least partially said container, seid second molten metal being frozen sheet along the surface of the molten substantially immiscible with and having a met-al bath;.' and means to remove the at least lower melting point than the rst mentioned 70 partially frozen sheet from the molten metal bath.

8. In an apparatus for forming metal sheets directly from molten metal, the combination comprisingr' a molten metal bath container, a molten metal in said container. said last mento be shaped onto the surface of the molten metal bath so that freezing' will occur at the interface of the two metals; means to engageY the edges of the sheet being formed to move the sheet along the surface of the molten metal bath; and means to remove the at least perf tially frozen sheet from the molten metal bath.

9. In an apparatus for forming metal sheets directly from molten metal, the combination comprising: a, molten metal bath container, a

molten metal in said container, said last mentioned molten metal being substantially immiscible with and having a lower` melting point and higher specic gravity than the rst mentioned metal; means to feed the molten metal to be shaped onto the surface of the molten metal bath so that freezing will occur at the interface of the two metals; means including two endless engaging means for engagingthe opposite edges of the sheet being formed so as to move the sheet along the surface of the molten metal bath; and means to remove the at least partially frozen sheet from the molten metal bath.

10. In an apparatus for shaping metal sheets directly from a molten metal, the combination comprising: a molten metal bath container, a molten metal bath being substantially immiscible with and having a lower melting point than the first mentioned metal; means to feed the molten metal to Ibe shaped into contact with the molten metal bath so that freezing will occur at the interface of the two metals; means to provide an inert atmosphere in contact with the' metal bath and sheet being formed; and meansV to remove the at least partially frozen sheet from the molten metal bath.

11 In an apparatus for shaping metal ,sheets directly from molten metal, the combination comprising: a molten metal bath container, a molten metal in said container, said last mentioned molten metal being substantially immiscible. with and having a lower melting point than the first mentioned metal; means to feed a sheet of the metal to be 'shaped into contact with the molten metal bath so that freezing will occur at the interface of the two metals; means to cool the face of the sheet opposite to .that firsty frozen; and means to remove the at least partially frozen sheet from the molten metal bath.

12. In an apparatus for shaping metal sheets directly from molten metal, the combination comprising: a molten metal bath container, a molten metal in said container, said last mentioned molten metal being substantially immiscible with andv having a lower melting point than the first mentioned metal; means 'to feed the metal to be shaped into contact with the molten metal bath so that freezing will occur at the interface of the two metals; means to cool the face opposite to that first frozen comprising a cooled roller to contact the face of the sheet opposite to that in contact with the molten metal bath; and means to remove' the at least partially frozen sheet from the molten metal bath.

CHARLES D. COXE,

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