US2285308A - Process for making wire or strips - Google Patents

Description

JpneZ, 1942. `YH,asnwcrfl` 2,285,308 l Y PRcEssFOR MAKING; WIRE on sTRls I l Filed July 51, 1940 `11m-E i f4 n a x S Y f5" c2157 PLATE mv/VEHLED Y AME/vLevcAsT PLATE PLH Ta foLLen ROL LED 11A-re f5* leo/ Lav mms mwwsnusp MNE/Lev ROL/.Ea Pumf PLATE cur SY CIRCULAR SHEAR /Nv-o JQUHRE. 0R

ATTORNEY Patented JuneZ,"

" l `tion ofMNewJersey' i w `Application July 31,

Thepresent` invention relates an improved isioifserial No. 348,513

processfor making wire or strips. and has `for an object `to"provide a processby ywhichwire or strips` may be produced rapidly` and economf ically, and which will beofuniform quality as `to the, surf ce fn and contracts more rapidly than the interior and therefore results'in a difference in structure and density between lthe sur- `face and the interior, as well as fractures and density, grain,` ftensile strengtin ductility,fani.` t u x y c centrifugally castplate impurities in the metal surface formation, and willbe free `from undesirable inclusions and voids. "A t It is particularly"proposedhaccording `to the 'process of theinventin to producewire or strips from` molten metal, suchfor example as copper,

aluminum,` soft steel, hardsteel, stainless steel, l

phosphor bronzegbrass,etc.,"by`nrst"forming the metal intoan annular cast discus `plate by centrifugal casting ina casting machineofthelver` tical type. `in which the-axis `of the centrifugal u from impure wastemetal.

fissures` in the surface, which subsequentlyappearinuand weaken `the finished wire. lIn the collect at the inner periphery, and the small ring of metal containingrtheseimpurities is later discameo-,lima method lof `centrifugal casting providing, a maximum of metal free from im-` puritie s,i` with a consequent reduction Ain" loss Thelnext step" in the process consistsin annealing the cast plateiftheparticular metal re- IquiresA it, and thereuponV rolling itf-either coldmoid is horizontnyarrangem `liccordim; to this method ofcasting themolten metalows to the bottomfoflthe rotating centrifugal iiioldin` ar downwardly jdirectedf' column, the volumel and rateof "flow of whiehfis" controlled in relation to the capacity and speed of rotation l lof the mold,

lowedtofescape *freely without interference or entrapment" by `the* entering 1 molten metal,` and `due to the continuous pickup of the metal at the 1: `bottom of thefmold,the` castmetal is of uniform rolled or `hot'rolled-into a circular plate of uniform thickness, the grain` differential between me` 'rianvely think limer part of iessdensity with the `resulttl'lat it ispickedup substantially j t andthe relatively thin outer part of greater density becoming equalized as the plateis rolledto uniform thickness.

The next stepconsistsin annealingy the rolled u plate, if the particular anetal requiresit,

thereupon cutting it in fa circular shear intoa a wire of squareV or' oblong cross-section;` this csheared `wlrefbeing thereupon annealed on not,

,structureannularlm and is `free from air pockets or `prematurely cooled `and hardened metal 1Vparl "ticles. Ingcentrifugally casting suchplates-there is a grain size andtexture differential between#- the` metal at the inner and outer peripheries', `the i ward the outer of the plate due `tothe `fact that it is subjected tothe centrifugal force of the ery,` andit is proposed according tothe invention cast mem being of greaterflldensityf radially u l depending on the requirementsofftheparticular metal, and finally formed-into or strip` stock by drawing or rolling.

vIn the shearing operation the resultant cross rsectional shape of theshearedwire is rectangu- :larfdue to the fact thatthe .shear cut is substanu l A tially perpendicular to the'upper and lowerl par-` allel surfaces of the plate, and thisrectangular cross-section maybe regulated byfspacing of the `shear cutfromthewilxed shoe which supports the edge of "the plateduring shearing, sthat the 4 shearedwire may be of' either-square or oblong by Athe particularmetaland the thickness and l Ndianieterldimensionsof theplatei lBy asubsequentrolhngpperation, which rollstheplate to l @ancheusfmmerenmwl af`uniform equalized,"

` Thescentrifugally east'plate is `of relatively u cross-sectiong therefore cooland contact rapidlypwithollt Betllflidmel'ential c structure and densityfandf' such i 'as 'inl the casting of "relatively plator biilebwherei cross-section. This cross-sectionzis determined and regulatedaccording tothe particular char'- acteristics of the metal being lworked.' "In draw- 1mg` the rectangular cross-section wire through f dies of circular-or other shape to give the desired g` cross-,section to t the finished wire, the u longer sidesof` a wire of `greater dimension` in one di- ,rection than the other u tendto `bulge out to; fill `the space in thedie. while the shorter sides'are` umore forceably compressedintothedie, and con-r sequently these shorter 4sidesfare` subjected to an 'increased ironing; and smoothing y action. v

-f With",` certain types offimetal, dependinr upon anduotherchancteristicl, thesurfaces Afornace bythefmeuyeununato rbecome com,

tively smooth upper and lower surfaces of the plate, and in this case the wire is sheared so that the cross-section is of greater dimension transversely, that is, between the shear cuts. With.v

other types .of metal the shear will produce a smooth clean cut which may be smoother than the rolled upper and lower surfaces of the plate, and in this case the wire is cut so that the transverse dimension between the shear cuts is lessA than the vertical dimension. In the case of metal which has a shear cut surface of about equal smoothness with the rolled upper and lower surfaces of the plate the wire-isV cut to square cross-section.l Another factorl to be considered in determining the cross-sectional shape` is the fact that with certain metals the shear cut tends to produce a concave shear cut surface, while with other metals the shear cut'surface may be slightly convex. or straight, or angular. In the case of concave shear cut surfaces the transverse dimension Awill preferably be `the smaller dimension so that in drawing such concave surface will tend to bow outwardly. In the case of rolling into strip stock the concave surface will preferably be engaged'withthe rolls to Vbecome flattened.L In the case of a shear cut surface and its action in the drawingdies or strip forming rolls, is free vfrom cracks, creases, overlaps and such other defects.

With the above and other objects in view, ernbodiments of'rthe process according to the invention and apparatus for carrying it out are shown diagrammatically inthe accompanying drawing, and these embodiments will be hereinafter more fully described with reference thereto, and the invention will be finally pointed out in the claims.

In the drawingz'l Fig. 1 is av diagrammatic illustration of the various steps in the process, and showing the several elements of an apparatus for carrying it out arranged in theorderof the successive steps oi theprocess. r Fig. 2 is a diagrammatic view 'showing the wire or'strip forming material in `its -various stages, from the cast plate to the finished wire or' strip. y

Fig. 3 is a sectional view of the cast plate as it is formed in the centrifugal casting machine. Fig'. 4 is a sectional view of the rolled plate in its form preparatory to being cut into wire. Referring to, the drawing, the first step in thev process according to the invention consists in centrifugally casting from suitable metal an annular discus plate Il in a vertical type centrifugal casting machine, consisting in the illustrated example of such machine of a rotary backing plate Il carrying a two-part circular mold, consisting of an inner mold part I2 and v an outer mold part I3, thelatter being provided v^with a centrall opening into which the pouring spout il prolectathe molten metal being poured into this spout and dropping `downwardly in the form of acolumn to the'bottom of the centrifugal mold, the rate of flow and the size of the column being regulated according to the size of the mold and the rate of rotation of the centrifugal casting machine. By this method of casting the downwardly iiowing column entering the mold is picked up by the rotating mold at substantially the same speed as the rate of ow of the column, so that the metal is built up annularly or spirally in the mold without any chance of pocketing air,A or allowing the metal to spatter so that prematurely cooled and hardened drops of metal may enter tinto the mass of metal of 'different temperature and hardness, and such as is the case with other types of casting,`particularly in centrifugal machines of the horizontal type.

Furthermore the arrangement of the column of entering metal is such that the air displaced in the mold by the annular or spiral building up ofthe metal is allowed to escape freely without interference with or entrapment by the entering column of molten metal. The centrifugal action is such that the centrifugal force is greater at the .rim ofthe mold than at the center and consequently there is a gradual differential in texture and grain of the metal between the inner and outer peripheries. In order to compensate for this the mold is shaped so that the cast plate will be of increasing thickness between the outer and inner peripheries, this increase in thickness beingv directly related to and determined by the texture, grain and density differential of the plate depending upon the thickness and diameter and the particular metal being worked, this being for the purpose of allowing equalization of the differential through a subsequent rolling operation which rolls the plate into a larger diameter and a decreased uniform thickness.

The next step in the process consists in annealing the cast plate, if the particular metal being worked requires this annealing step prior to the rolling operation. Where such annealing is not required this step is eliminated. The cast plate annealing apparatus is indicated diagrammatically at I5.

'I'he next step consists in rolling the cast plate to a larger diameter and to a decreased thickness which is substantially uniform throughout the plate, this rolling process resulting in an equalization of the differential in density, grain and texture of the cast plate. I'his'operation may be carried out either as a hot-rolled or a coldrolled operation, depending. upon the particular metal ybeing worked. In Fig. 1 the plate rolls are indicated diagrammatically at I6 and The cast plate is subjected to at least two rolls, the iirst roll, as indicated at l0* in Fig. 2, imparting to the cast plate an oval form and the second roll, which is at right angles to the direction for the first roll, imparting to the oval plate a circular form, as indicated at l0. It will be understood that in certain cases the plate may be subjected to a greater. number oflrolls, and that with certain types of metal which may require it theplate may be subjected to annealing steps between the rolling operation.

The next step 'consists in annealing the rolled plate prior to shearing the plate into wire form,

indicated diagrammaticaily at I8.

a The next step consists in cutting the rolled plate by means of a circular shear into a coutinuous l length ofgwire of eithersquare or `oblong crossfsectionl" the shearing apparatus, 4indicated diagrammaticaily in Fig; 1, consistingn of a pair oftshearing dise cutters* wand zthaving their axes: disposed at 4substaiianni rightwaneies to each other" and their peripheral "cutting edges substantially meeting," there being a stop `plate 2| disposed beneath the `periphery or the `cutter disc Il A spaced relation tof the `periphery of the cutter-disc 2l, and whichfsupportsthe edge of the"rolledplate `during the shearing "operation,

the spacing permis stop plate from the `dise zo l determining the traiisverse` dimension fof the sheared wire. The dises arerotated and rotate the disc as it is cut, the peut beingusubstantially spiral. Thegcutwire is preferably reeledas `it is cuttfor convenience inannealingif such annealing `step is neeessarmfdllnding" upon the particular metalbeingworked." Where suchanneale ing stepis not Iiecessarythe cut wire may be fed directly "into` the apparatus `for working the `sheared wire into nished wlreor strip form,

as "will `presently more fully appear. e The spiral cuttingof the "plate into" wire form is continued untill `the`relatively small ring" oifegwasteV metal n me isreaehed,"`wiiereupon the end of` the wire is snippedf from "fthis remaining `ring which is `discarded,Iaridfvjzhich contains the impurities in the metal which e have"` been "concentrated therein by thecentrifugaleasting step. e y i s above pointed outthewshearedwireof rec-` tangular cross-section indicated"fat` ind is subject toan annealingfstepvifjsuch step is necessary, theosheared wire` annealing apparatus being indicateddiagrammatically at 22. i n

e The `shearedk wire` is `thereupon"subjected Ato either "a `drawingoperation by means of drawing tapparatus, indicateddiagrammatically at 23, toA n form thersamelinto finishedwire `which may be of circular or other desired cross-:sectional shape,

or to a rollingfoperation 1by` means ofl rolling "apparatus,` ir'idicated`h`diagrarnrnatieally:` at 21, to rollithe shearedwire into atstrip forrn.` The l iinished drawn"wire isfindicate tjlll", andthe and the rolling apparatus in the case; of rolling `strip stock.A With certain types of metal, particularlythose ofsofttempen'as lead Ifor example, there isla tendency forthe circular shear to tearand throw up burrsuponthe sheared surface, and in certain "cases aportionof the shear cut may be smooth whilelother portions `may be crumbly, torn or burred.` Also with certainmetal the shear cut may produce a concave sheared surface while with others fthe cut surface will be convex or angular. With other types oi metal,

as stainless steelfor examplathe shear out may `be relatively smooth, `andi in some `cases may be `smoother than the rolled upper and lower parallel surfaces ofthe plate. It has been found in `carrying out my process that in the drawing operation the `action of the drawing dies upon a `square cross-sectionis substantially equal upon all sides, whereas in `the case of an oblong crosssection the longer dimensioned sides tend to bulge out to ll the side spacesjin thee drawing 'jected to an increased `compressing and smoothingironing` action. Consequently,lwhen the particular metal being worked `or sheared," "an "analysis is made of the shearedlmaterial towdetermine whetherthe long "dimension of the `sheared material shall be betweenthewshear 4 cuts `or `between the `uppe`r""`and ilower [or rolled surfaces of the material. Where `the 'sheared surfacetends to be concave,` `therehort"`dimension is preferably between the sheared sides, while in the case of a convex or angular shearcutfthe sides. i l t i w l e It zwill be seen from the `abovethat the wire or strip stock producedaccordingto thelprocess of n the invention is of uniform quality as toldensity,

grain, duetility and tensile strength,` andisfree frcm` such imperfections as cracks, creasesfovert lapsand the" like,` which have been present in wiresandstrip stock produced? accordingto previously known processes.` The process permitsof rapid land economical production of wirejand e strip stock with a minimum of loss duetoiwaste t metal"` containing impurities. "The process 'fur- Mthermore lends" itself to "working "Withyarous c metals of widely diilerent charaeteristics-"` 'I have illustrated and described preferred "and satisfactory embodiments of the invention,` f but it will` be understoodthat changes may be made jth'erein, within the spiritand *scope thereof; as

definedfinlthe appended claims. *n

Having thus `described myinvention, `what `I claim and desire to secure byLetters vPatentis:

`l.` The process for making Wire"orstrijgimstock1 which `comprises centrifugally e `desting molten metal into an annular centrallyf apertureddiscus plate in "a "vertical type centrifugallcasting machine in which the revolving mold is rotated around a horizontalaxis at aspeed controlled in substantially synchronous relation"` to the type, `volume;` and speedofflow of molten metal poured into the mold in a downwardly directed `column from acentral entering hole in the mld,*"the plate being cast of `gradually increasing"`thick ness from theoutert the inner periplieries and such thickness being `in `substantial proportion to the grain size andl texture diiferential between the "inner and outer peripheries` resulting from e vertical n centrifugal "casting, rolling 1 the cast plate to a larger diameter `andanapproximate uniform e thickness throughout to'prodoe g tf sided centrally aperturedcircular rolled "plate,

cutting the rolled piste into a continuous` length n of wire of substantiallyrectangular `cross-section by a spiral cut extending inwardly from the outer die, while the shorter dimensioned sides are subi `periphery between the fiat sides of said plate,

and subjecting the cut wire to a iinishing opera-` tion to produce finished `wire or strip stock.

I 2. The process for making wire or strip stock,

which comprises centrifugally casting` molten metal into an annular centrally apertured `discus `plate` in a vertical type centrifugalcasting machine in which the revolving mold is rotated around a horizontal axis at agspeed controlled in substantially synchronous relation to the type, e

e volume, and speedof ilow of molten metal poured into the mold in a downwardly directed column from a central entering hole in the mold, the

plate being cast of gradually increasing thickness from the outer to the inner peripheries and such thickness being in substantial proportion `to the grain size and texture differential t between the inner andouter peripheries resulting fromvertical centrifugal casting, rollingthe cast `plate to a larger diameter and an approximate uniform thickness throughout to `produce a fiatsided centrally apertured circular rolled plate,

long dimension is preferably betwee the sheai'ed Vwhich comprises centrifugally casting molten metal into an annular centrally apertured discus plate in a vertical type centrifugal casting machine in which the revolving mold is rotated around a horizontal axis at a speed controlled in substantially synchronous relation to the type, volume, and speed of now of molten metal poured into the mold in a downwardly directedrcolumn from a central entering hole in the mold, the plate being cast ofgradually increasing thicknes from the outer to the inner peripheriesA and such thickness being in substantial proportion to the grain size and texture diilerential between the innery and outer peripheries resulting from vertical centrifugal casting, annealing the cast plate, rolling the cast plate to a Alarger diameter and an approximate uniform thickness throughout to produce a atsided centrally apertured circular rolled plate, cutting the rolled plate into a continuous length of wire yof substantially rectangular cross-section by a spiral cut extending inwardly from the' outer periphery between the fiat sides of said plate, and subjecting the cut wire toa finishing V operation to produce finished wire or strip stock.

v4. 'The process for making wire or strip stock, which comprises centrifugally casting molten metal into an annular centrally apertured discus plate Ain a vertical type centrifugal casting machine in which the revolving mold is rotated around a horizontal axis at a speed controlled in substantially synchronous relation to the type,

volume, and speed of flow of molten metal poured into the mold in a downwardly directed column from a central entering hole in the mold, the plate being cast of gradually increasing thickness from the outer to the inner peripheries and such thickness being in substantial proportion to the ygrain size and texture differential between the inner and outer peripheries resulting from vertical centrifugal casting, annealing the cast plate, rolling the cast plate to a larger diameter andan approximate uniform thickness throughout to produce ay flat-sided centrally apertured circular rolled plate, annealing the rolled plate, cutting the rolled'plate into a continuous length of wire of substantially rectangular cross-section by a spiral cut extending inwardly from the outer periphery between the flat sides of said plate, terminating the spiral cut short of the inner periphery whereby a ring of metal at the inner periphery containing impurities remains, annealing the cut wire, and subjecting the cut wire to a finishing .operation to produce finished wire or strip stock.

5. The process for making wire or strip stock which comprises centrifugally casting molten metal into an annular centrally apertured discus plate in a vertical type centrifugal casting machine in which vthe revolving mold is rotated Varound a horizontal axis at a speed controlled in substantially synchronous relation to thel type, volume, and speed of flow of molten metal poured into the mold in a downwardly directed column from a central entering hole in the mold, the plate being cast of gradually increasing thickness between the outer to the inner peripheries and such thickness being in substantially proportion to the grain size and texture differential from the inner and outer peripheries resulting from vertical centrifugal casting, rolling the cast plate to a larger diameter and an approximate uniform thickness throughout to produce a fiatsided centrally apertured circular rolled plate, cutting the rolled plate into a continuous length of wire of 'substantially rectangular cross-section by a spiral cut extending inwardly from the outer periphery between the fiat sides of said plate, whereby a length of wire of rectangular cross-section is produced having substantially parallel upper and lower rolled surfaces, and controlling theY distance between the shear cuts depending upon the comparative differences in the surfaces of l' the shear cuts and the rolled surfaces, whereby the rectangular cross-section is either oblong with the greater dimension either between the shear cuts or between the rolled surfaces, and subjecting the length of wire to a finishing operation which has a differential finishing action with respect to the longer and shorter sides of the cut wire. Y

v HARRY G. SPECHT.

Images