. 3,_v 194.6. 2,41 1,998' J. F. KELLY El'AL METHOD OF MAKING MOLDS Original lFiled Sept. 18, 1939 ma` w KV œ_, m _uw , O. f2 1\\ ä 4 // /A \\ _N /m nn. 2l NÚM ..w / _ ß .v.. ///„// YF_ ///// /W /. ,6v6. ,. . . . wN/n Wf/m Mx/rl. /.l J/lm o„„` Tl...9 N, 3 ß @m , ,J,_ 2,411,998 Patented Der; '3, '194e i UNiTE-D srA'rssi-rA'rßur oFFlc ' 'Y ` A " _ ¿411,998 `_ ¿ ' l' METHOD 0F ma' LIOLDSV John n.` 'Kelly and wlmm J. muy, mm, W. va., asslgnors to Kelly Foundry and Mag chine Gompanbßlkins, W. Va. Original application September 18. 1939, Serial No. 295,551, now Patent No. 2,326,730, ’dated _ » August 10, 1943. Divided and >this application Y June 12, 1943, Serial No. 490,580 ' _ x ._ . 1`Claim. ' (CL 76-107) , » , lI 2 . application Serial Number 295.551 flied Septem of making same.” The present application has to . that'the surface Y 'I'he prior art has r ’ both cast iron as well as pure nickel have been. proposed as materials for such molds.- With such . limitations as cost, a nickel glass mold cannot be > molds and to the method of making as well as made thick enough so that its outer surface has enough area to_ effectively- dissipate the heat. It - The primary object of this invention is to pro hasbeenproposedtocastaringofironaround A such a nickel insert. however, in absence of fusion between the cast iron and the nickel insert there one surface thereof suited for glass molding work and in which the two parts of the construction are so fused together as to enable eillcient transmis sion of heat away from` the cavity to the other ` . of a glass mold must be free from oxidation, and to the process of making such constructions. More specifically, the invention relates to glass Other objects of this invention' will appear as , other dimensions to be produced. f do with the process involved in said application. This invention relates to bi-metallic construc tions wherein two metals are united together and surfaces of the mold. ' certain dimensions that the mold may be ma chined vto a new shape' thus enabling articles of '730, dated August;` 10, 1943, for Mold andmethod duce a low cost bi-metallic construction having , As Yan example of this latter feature, we point out that afterl using the mold for producing articles of ber 18, 1939, which matured as Patent No. 2,326, the method of using suchmolds. - I for several different shapes of articles. This application is a division of our co-pendihg would be considerable resistance to heat iiow at the junction of the nickel and iron. l The present invention contemplates a glass mold in which the „innerstainlesspartisfusedtotheouterlayer of cast iron, which outer layer is made very thick this description proceeds. soitwillhavebothalargeexternalsurfacearea In carrying out the above object, we use an and a large heat dissipating area. Such a glass inner layer of a chilled, corrosion resistant cast mold characterizes the present invention, and we iron which deñnes the cavity of said mold. 'I'he material which we employ in the construction u have found it to be a very marked improvement ‘ over glass molds known to the prior art. of the glass forming implements hereof, which A proposal that has been made by inventors comprise a. glass" mold and a plunger,-is prefer of the prior art is to weld, by ordinary welding ably a nickel-iron alloy having a nickel content methods, a non-oxidizable lcoating upon an» well above 20% although this particular alloy is not essential and our invention may be carried 9o oxidizable metal but that proposal differs consid erably from our invention and it also has certain _ out with various heat resistant materials. Dur disadvantages which do not occur with our proc ing the manufacture of this mold, the nickel cast ess. Such prior art molds as we' just mentioned iron part is machined on its >outer surfaces Iso it are subject to the great disadvantage er being _ will be quite clean. It is essential to remove all foreign matter from this surface by a good clean __” inicompletelyV welded, the disadvantage of having _ air pocketsv at the joints,»and they can ordinarily ing process and we have found machining to be q‘uite satisfactory. This part is then heated to j > >be built only when simple :cavities are used. Ac 1600° F. in a non-oxidizing medium, transferred.- c_ol'i'llngly,> it is apparent that when the mold of our invention is compared with’molds of the prior to a foundry mold in such a manner .that its con' _ coated 4° Vart suchras the prior molds'recited above, it is _ tact with the air is very brief, and then ¿¿ with a very ¿thick layer of cast iron bythe step _ „seen thatweîhave made considerable improve»> ments nomine standpointsengneat conductivity, Y C v With of casting our `process, ordinarythe cast ordinary iron about castironïfuses theisame. cost, and _surface ch_arac‘tex'isti_cs.> with the nickel-'iron 'alloypart and thereby creates “_moldthan atovery'emcient the _outer surfaces heat'ilowofpath the from the `Thep'resent invention-~v _satisfies require which‘was 'cast in a'sand _ mold.. v_When 'irmfis castfagainsta chill,_the offthe `chill mold conducts heat @am °f I . i v' _ ¿chilled cast iron__ makes'a muchbetter __ _ _ _ _ glass -` Y Y»away-"frolnfv the hot _iron causing' the latter to ments'o'f aïfgoodglass mold in lthat it providesa-Í , -cool’rapldm the resultant casting v efficient. louniformanddense.- Howevergincaßtináaglass " - Y._ „ non-oxidizable-molding surface as _well as> ' heat dissipation from the molding cavity to outer ' surfaces ,of thev mold. - Moreover,_f themew mold is'inexpensive‘to manufacture, can b_e maná; ' - . ufactured withoutïappreciable'probabilityof uri--ï _ reliable operation, _and may be mold siichïasinventors of :the prior art.' 1t'is_„1m_.with usual casting methods to. set vthe center working section ‘of> tbecasting '.asdmseasdesired. ` " » - ' 2,411,998 4 . a chill and since this insert is relatively thin it _ becomes very dense throughout. With our proc the process. Instead of coating the part II with lampblack, it may be coated with copper by elec ess, ‘an outer layer may be cast onto as well as troplating. The insert I l is then placed in cham fused to this insert without destroying the nigh ` ber 22 which chamber is only slightly larger than degree of density _of the insert. Hence, we can the insert II. This chamber 'may have a char produce a glass mold which is very dense in its coal lining but this is not necessary. A removable ` central working section. To avoid cracking the cement lid 23 is placed on-chamber 22. 'I'he thin inner part or insert, it is desirable to use .chamber 22 is then placed in a gas furnace 34 metals for both'the inner and outer layers which of any suitable type but preferably a furnace in have similar coemcients of thermal expansion as l0 which a large number of jets 2| emerge tangen well as similar melting points. tially from the inner surface of the furnace 34. Inthe drawing: ' The Jets 2| are so arranged that a smooth band , Figure 1 illustrates a machine for manufactur ing glass articles and includes a'glass producing ' machine, a glass mold. a plunger, and a valve. ' - Figure il- is a top view of the mold of Figure 1 without the plunger, valve, or glass producing machine being shown. - ' ‘ of flames exist, for-a distance of about three inches from the inner wall of furnace 34. 'I‘he overall diameter of the furnace is lthree to ñve feet. 'I'he Jets all face in the same angular di rection and propel the flames around the inner wall of the furnace. The hot gases pass out the Figure 3 illustrates apparatus that may be em- ' openings‘ua respectively located at the top and ployed in carrying out the process which is 20 bottom of the furnace 3l. As a result, the llames claimed to be our invention. and hot gases act on al1 sides of chamber 22 _ Figure 4 is a sectional view of a chill mold that 4 may be used for casting nickel-iron -alloy inserts. V In Figure 1, an outer grey or white cast iron sleeve I0 surrounds- and is fused to the inner forcing heat4 evenly into this small chamber to such an extent that insert II is evenly heated to 'a temperature well above red heat and preferably to a temperature above 1600’ F. ._ nickel-iron alloy part II. While this specifica tion specifies that cast iron is used for layer III, When suillcientv time has elapsed for heat to fully penetrate the insert II to raise the same to we recognize that any good heat conductor-such say 1600“ F. yor~ slightly hotter, the entire as copper or aluminum may be used in forming small chamber_22 is removed to position 22a . layer III without departing from the very broad 30 where it ls adjacent the foundry mold 35. If est aspects of our invention. The insert or in the insert II were transferred to position IIa ner part II defines a cavity Isa 'of a shape, for without using the chamber 22, the insert would example, conforming to the outer surface of an oxidize slightly and impair the resultant glass - ordinary drinking glass. The surface I3 of insert mold. When at position 22a, the lid 23 is re ‘ I I is machined to such a shape. 35 moved and the insert IIa removed and quickly A plunger is often used in glass manufacturing brushed so as to remove the carbon which was de machinery and a suitable plunger is shown in Fig posited or smoked on the insert previously. In ure 1 directly above the mold cavity Isa. This event the modified process is used wherein the plunger has a cast iron 'section I4 with an outer insert is coated with copper it is not necessary to layer I5 -of nickel-iron alloy cast iron fused 40 remove the coating. After being brushed, the thereto. 'I'he surf-ace of layer I5 conforms to the insert I I is placed in the foundry mold 35 at posi shape of the inner side of the glass articles to > tion IIb. The foundry mold' 35 is then quickly be produced, for example, it may conform to .the assembled and ordinary grey cast iron poured into inner surface of said drinking glass. >In addition the cavities 30a of this foundry mold. A ladle 3I Ito the .mold and plunger, most glass manufac is used to supply the grey cast iron into the sand .turing equipment of the type being considered em top 3U which defines the gate 30a. A vent 33 of ploys a valve which in Figure 1 is shown directly , dry sand core material is used to remove the hot below the mold cavity Isa. This valve has a gases from the molding chamber within 35. It white or grey cast iron base I2 with a nickel-iron is understood that the insert I I is substantially at alloy coating I3 fused thereto. 50 1600° F. at the time the outer layer I0 is cast The method of manufacturing glass molds such thereon by the process Just outlined. asvthose shown in Figure 1 will now lbe described, Since the nickel-iron alloy part II is the only ' _reference being made particularly to-Figure :iL although like parts von all figures are represented by like numbers. i» ' - o , An alloy insert I-I, of suitable stainless metal partof our mold that comes into contact with the hot glass, it is not absolutelyessential that » foundry mold 35 have chill walls although it is desirable that it does. Ordinary sand walls will such as the alloys described elsewhere in this dis A be satisfactory. The nickel-alloy part II has ex closure, is ilrst cast in` a cylindrical chill `mold cellent heat and corrosion resistance yet a _melt having thick chill walls. The cavity I3a may be ing mint» approximately the same as ordinary , cast into the insert originally or it may be ma 60 cast iron.v All of the iron alloy compositions de chined into the insert immediately after the cast scribed indetail in this disclosure have melting ing step is completed. Preferably, however, the points between 1990° F. and 2280° F. and Vwhen cavity Isa is machined into the mold asthe last such alloys are used in making insert I I, it `is step in the production of the mold. necessary to'heat the <insert to only about 1600° After being cast, the outer :surfacexwall Aof 'in-. F. in furnace 34. The insert II is further heated _sert II is thoroughly cleaned, preferably by ma on its outer surface by the hot cast iron coming chining the outer parts of this insert. Anyn'clean ing method that thoroughly cleans the out`er sur' face of part II will be within the teachings of into the foundry mold 35 and the' temperature of the insert is thereby raised to the fusion point. Hence, the cast iron from ladle‘ 3| thoroughly this disclosure, however. After being cleaned, .the 70 fuses with insert II and a wide band of alloy be insert is then covered -with a coating of lamp black, or it may be- smoked by the smoke from an acetylene torch. This coating is placed on the outer surface of the part II to prevent the part from being oxidized by subsequent steps of tween the two is formed in the mold. This wide band is illustrated in Figure 1 and specifically designated by reference number 36. With ordi nary welding methods alloying between the parts of the resistant mold would be restricted to a very narrow band and asa result‘the iunction would be quite inferior to the junction of our invention Preferred Minimum, Maximum, Element percentage per cent per cant wherein very intimate association of the parts I0 and I I is eiîected. If an insert I I is used which has a melting point higher than 2280° F., it is desirable to heat the insert II to a temperature well above 1600“ F. before pouring iron from ladle 3|. On the other hand, if an insert II should be used that has a very low melting point, perhaps little or no preliminary heating of it would be necessary. l ` Carbon ..................... -_ Chromium. 20.00 2. 50 l. 50 Silicon ____ _- l. 25 1.00 3 00 Manganese Copper....- l0. 00 0. 50 0.00 12. Il) 3.00 0.00 0. 00 1.00 1.00 Tungsten ...... -_ ‘ v Molybdenum ____________ ._ 6.00 4.00 35.00 Balance is iron with usual impurities. Another type of iron which may be used for either the insert II or the plunger surface I5 is: ’ We also recognize that the glass mold of Fig ure 1 can be manufactured by a modified process now to be described. The outer part I0 is first Preferred Minimum, Maximum, Element cast in the foundry mold 35 with, a dry sand core at IIb instead of the nickel-iron alloy insert. The outer part I0 is then removed from the mol-d and the cavity which was produced by the'core IIb percentage Total carbon _______________ _- 3 70 Silicon---" of. The outer part I0 is then placed-in the fur 20 nace 34 and heated almost to its fusion temper 3.00 per cent 4.00 2. 10 1. 00 3. Il) " _ l. 00 0. 00 2.00 Chromium.._ Molybdenum .............. _- 0. l0 0. 90 0. 00 0. 00 LII) 1. 00 .Nickel ..... __ machined so as to clean the innersurface there per œnt Balance iron with usual impurities. ature at which time it is used as a mold and the nickel-alloy inner part I I poured directly into the cavity of the part I0. This may be done while Thev above types of alloys as well as the ones listed below are all melted in a cupola according part I0 is still in the furnace 22 or it may be done 25 to standard foundry practice for these general after the part I0 is removed from furnace 22, but in any event it must be done while outerk part III is hot. The cavity I9 is then machined into the inner part II. As shown'in Figure 1, both the plunger and the 30 types of irons and poured into permanent molds having thick metal chill walls. The cast `iron that is poured into the gating 30a of Figure 3, to form the outer layer III of Fie valve may be of bimetallic construction. Either may be produced by the processes recited above. For example, the nickel-iron alloy piece I5 may be illustrated also in Figure 1, has a preferred com- ' ure 1, and the iron used in making the section I4 position of total carbon 3.5%; and/silicon 2.20%. The carbon content Works well between the lim its of 3.00 to 4.00% and the silicon may vary 1600° F., transferred to a mold in a suitable small 35 within the limits of 1.50% and 2.75%. The bal-ance isiron with usual impurities. This latter chamber similar to chamber 22, and cast iron I4 iron may be used for the insert Il and surface I5 poured thereinto. It is also apparent that part but it is not as good/as the other alloys for that Il may be cast first and partl I5 later. use. It is quite satisfactory for the insert Il and While the nickel-iron alloys contemplated by this invention are relatively stainless it has been 40 in fact a mold constructed according to our proc ess, even with this type of iron for the insert, is _ found that after atime, in fact a rather long time as compared to ordinary glass molds, their sur superior to prior art molds inasmuch as our proc- . ess enables fus to thoroughly chill such a cast iron faces become less efficient than the surfaces of and thereby greatly improve its qualities above new molds. When this occurs, the mold surface may-be machined to new dimensions I1, and the 45 the qualities that would be obtained if such ordi nary cast iron were used in any ordinary glass plunger I5 may be machined to new dimensions I8. Further pouring of glass from 'I5 will pro _ mold vof the prior art. Those skilled in the art understand that any duce glasses having a thick wall instead of a thin of the cast irons disclosed above, as poured from wall as originally. ‘ machined to shape from the cast state, heated to As heretofore stated, the broadest' aspects of 50 the cupola, have large quantities of combined carbon but upon striking the chill mold precipi-V tate most of this combined carbon into graphite. The graphite makes the iron uniform and dense. It is apparent that with our mold, _the combined ferred composition for the insert Il is: 55 `carbon is very eillciently changed to graphite ‘ad ljacent our molding surface I9. this invention are not limited to any particular material for either the insert' I I or the outer partA III. Suitable materials are listed below. The pre Element Preferred Minimum, Maximum, percentage per cent .per een Carbon ..................... ._ 3. 00 2. 25 3. Silicon ____ _. 2.00 1. 00 3. Mangan Chromium 0. 70l 3. 50 0. 50 0. 00 l. '6. 29.00 20. 00 50. 1. 00 0. 00 2. Nickel. . _. Molybdenum .............. _- We claim: ' 'I'he method of making a steel liner'in a glass ‘ . mold which consists in the steps of casting a liner 60 of heat-resistant noncorrosive ferrous alloy 'with thick chill wall to pro duce a liner the outer wall layer of which is ` its outer‘surface against a chilled, cleaning the perimetral surface >of the liner, heating the liner, casting' a mass of cast Usual impurities, balance iron. 65 iron around the perimetral surface of the heated . liner to fuse the chilled portion of the liner and The above alloy is suitable for use on vthe sur face of the plunger as'well as for use in insert II. the exterior mass, and machining out the inte- ~ ç rior ofthe liner to provide a thin glass forming ` m`old surface in the outer portion of ~the chilled Another alloy suitable for either the insert II 70 Iwall layer of the liner. or the plunger surface I5 is: JOHN F. KELLY. A WILLIAM J. KELLY.