US2368719A - Temperature control mold - Google Patents

Description

3 Sheets-Sheet l INVENTOR. farMaA/o J M4452 Feb. 6, 1945. R'. .1. MILLER TEMPERATURE CONTROL MOLD Filed Dec. 17, 1942 Feb. 6, 1945. R. J. MILLER TEMPERATURE CONTROL MOLD 3 Sheets-Sheet 2 Filed Dec. 17, 1942 IN V EN TOR. .64 ova/v.0 J/V/u. :2

Feb. 6, 1945. R MILLER 2,368,719

TEMPERATURE CONTROL MOLD Filed Dec. 17, 1942 5 Sheets-Sheet I5 2 0 490 202 ;s\\\\\ y x\ 1 By M Patented Feb. 6, 1945 UNITED STATES PATENT OFFICE TEMPERATURE CON TBOL MOLD Raymond J. Miller, Detroit, Mich., assignor to Miller Engineering Corporation, Detroit, Micln,

, a corporation of Michigan Application December 17, 1942, Serial No. 469,301

11 Claims.

- This invention relates to the art of casting, and more particularly to the formation of improved molds to control the dissipation'of heat from molten alloy or metal to provide castings of uniform high quality free from shrinkage straim. j

' Molten alloy or metal is introduced into a mold, and when it solidifies a casting is produced conforming to the shape of the mold cavity. solidification of molten alloy or metal is accompanied by shrinkage or a reduction in volume due to a contraction of the space between the molecules of the molten substance upon passing from the liquid to the solid state.

The period of time required for molten alloy or metal to solidify depends upon the rate of heat transfer, and the rate of heat transfer is dependent on the ratio of the area of the cooling surface of the mold and thevolume of the casting. In the formation of castings having sections of varying contour, the light or thin sections have a greater ratio of surface area to volume in contact with the mold cavity than do heavier or thicker sections. Other factors being equal the light or thin sections cool more rapidly than do heavier or thicker sections, and the light sections will solidify while the heavier sections are still molten.

tained in the molten state until the casting has 7 solidified.

In the formation of castings a shrinkage com- To accomplish this desirable method of controlling the coolingof it is necessary that the rate of heat dissipation be accelerated from the heavier or thicker sections of the cast-.

ing, and that the rate of heat transfer from the feeder and the light or thin sections lying be tween the feeder and heavier sections of the casting be retarded to maintain these light sections and the feeding in the molten state until the-heavier sections have solidified.

The mold may be formed of many different types of materials, since all that is necessary is that the mold-forming substance be capable of conforming to and maintaining the shape of a pattern of the article to be formed to provide the mold cavity. Where the mold-forming substance is homogeneous throughout, the rate of heat dissipation by radiation from a mold varies almost in direct proportion to the external surface area of the mold to the unit volume of the casting to be formed, and the cooling effect of the mass of the mold by conduction is substantially in inverse proportion to the volume of the mold cavity at any point.

No readily usable means has heretofore been available to vary the rate of heat transfer from various portions of a. castingto provide substan- Shrinkage strains of considerable magnitude are thereupon introduced in the casting because of the isolation of the heavier or thicker sections from the shrinkage compensating supply of molten alloy or metal at the feeder to maintain the tially uniform or progressive cooling of a casting. Difficulties have therefore been experienced in the casting of articles having sections of widely varying contour, since shrinkage stresses of considerable magnitude are developed and inferior castings result.

In the Capaco process of molding as disclosed in Patent No. 2,201,037, issued May 14,1940, plaster is used as the mold-forming substance. The plaster is subjected to a drying operation whereby virtually all the moisture is dispelled. The resulting mold has a very smooth glass-like internal surface, and fine-grained homogeneous castings having smooth external surfaces are formed. These castings may generally be used without any machining work, since it is possible to hold them to very close tolerances Until now it has been impossible to use this method of molding anything except relatively small articles where shrinkage strains caused by wide variation in sections would not be objectionable.

My copending applications, Serial No. 455,862,

filed August 24, 1942, and Serial No. 458,265, filed September 14, 1942, disclose methods of forming temperature control molds to provide progressive .or substantially uniform cooling of castings having sections of varying contour. The flasks employed in the formation of the temperature control molds disclosed in said applications are more or less specialized in that a flask is selected'to conform generally with the shape and contour of each article to be formed, and the temperature control mold is formed between a pattern of the article and a mold former associated with the flask.

This invention is directed to an improved method of forming temperature control molds from standard pattern and flask equipment. Where the article to be formed is of such size that more than a single pattern may be positioned in a standard flask, a plurality of casting cavities surrounded by suitable temperature control mold members may be formed in a single flask.

In the Capaco process of molding, a plurality of different patterns of varying size may be formed on a plurality of blocks of graduated sizes'posltioned in a single flask to form a die pattern. Molds having a plurality of casting cavities are formed from the die pattern by applying a gypsum compound to the die pattern, No provision has heretofore been made for controlling the. rate of heat dissipation from molds formed from die patterns. This invention includes the formation of temperature control molds formed from die patterns to insure progressive solidification of each of a plurality of separate castings in molds formed from die patterns.

1 An object of thisinvention resides in the formation of temperature control molds in standard flasks to insure progressive solidification of castings formed in such molds.

. Another object is to provide a temperature control mold having a plurality of casting caviies formed between pattern and mold contouriorming members associated with a flask of standard 'size.

A further object resides in the formation of temperature control molds formed from standand die patterns to provide progressive cooling toward the point of feed of each of a plurality of castings in die pattern-formed molds.

Yet another object of this invention is to provide an improved method of forming, in standard flasks, temperature-control molds having one or more mold cavities wherein the external surface area of the mold-forming substance is substantially proportionate to the volume of mold cavities throughout.

Another object resides in the development of a simplified method of forming temperature control molds in standard flasks whereby the heat transfer from one or more castings formed in the'mold may be controlled to provide substantially progressive cooling towards the point of feed over the entire area of one or more castings being formed.

Still a further object of this invention is to provide a simplified method of controlling the rate of heat transfer from castings in mold cavities formed in standard flasks by contouring the body of the mold-forming substance to accelerate the rate of heat transfer from heavy or thick sections and to retard the transfer of heat from lighter or thinner sections of the castings to provide substantially uniform or Progressive solidification of one or more castings formed in a single mold.

Another object is to provide plaster temperature control molds in standard flasks and having one or more similar or dissimilar mold cavities wherein the mold-forming substance has substantially constant volume throughout to permit moisture to escape uniformly over the entire mold surface to insure substantially uniform drying of the mold.

Yet a further object of this invention resides in the formation of plaster temperature control molds between standard die patterns and a mold contourformer superimposed on the die pattern to provide a temperature control mold having a progressively decreasing ratio of external surface area to volume of mold cavity toward the point of feed of each casting cavity to form castings of uniform homogeneous structure free from shrinkage strains.

Still another object is to provide a simplified method of using standard pattern and flask equipment in conjunction with cooperating moldforming members to provide temperature control molds having one or more casting cavities surrounded by mold-forming substance adapted to provide progressive cooling of the casting toward the point of feed either by radiation or conduction or the combination of radiation and conduction-to provide castings having sections of varying cross-sectional area free from shrinkage strains.

Otherobjects and advantages of this invention will be apparent from the following detailed description'considered in'connection with the accompanying drawings, submitted for purposes of illustration only, and not intended to define the scope of the invention, reference being had for that purpose to the subioined claims.

in the drawings wherein similar reference characters refer to similar parts throughout the several views:

Fig. i is a plan view of a unitary pattern of any article having sections of varying cross-sectional area to be formed by a casting operation.

Fig. 215 a longitudinal sectional view taken 1 substantially on the line 2-2 of Fig. 1 looking in the direction of the arrows.

Fig. 3 is a sectional view taken substantially on the line 33 of Fig. 1 looking in the direction of the arrows.

Fig. 4 is a longitudinal sectional view of a matched plate pattern formed from the pattern illustrated in Figs. 1 to 3 and having a frame shaped to fit a, standard flask.

Fig. 5 is an exploded view of the matched plate pattern and the cope and drag temperature control molds formed in standard flasks between opposite sides of the pattern and the upper and lower temperature control mold-forming mem- Fig. 9 is a plan view of a unitary pattern of a. gear segment of such size that a mold having a plurality of casting cavities of the gear segment may be formed in a standard flask.

Fig. is a sectional view taken substantially on the line lllll of Pig. 9 looking in the direction of the arrows.

Fig. 11 is a sectional view taken substantially on the line il-ll of Fig. 12 looking in the direction of the arrows and showing the formation of a temperature control mold in a standard flask between a plurality of production pattern segments formed from the unitary pattern illustrated in Figs. 9 and 10, and a contour former to provide the mold with external surface area proportionate to the area of the mold cavities throughout.

Fig. 12 is a fragmentary plan view of the temperature control mold illustrated in Fig. 11.

Fig. 13 is a longitudinal sectional view of a temperature control mold former for a die pattern assembly.

Fig. 14 is a longitudinal sectional view of a die pattern.

Fig. 15 is a longitudinal sectional view of a mold formed from the temperature control former of Fig. 13 and the die pattern of Fig. 14.

Fig. 16 is a sectional view of assembled cope and drag temperature control molds assembled preparatory to forming castings.

Before explaining in detail the present invention it is to he understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also it is to be understood that the phraseology orterminology employed herein is for the purpose of description and not of limitation.

Figs. 1 to 3 illustrate a unitary master pattern ll of an elongated article having a thin, contoured, generally rectangular, flat plate I 2 provided with an elongated aperture M. The periphery of the plate 12 is provided with upwardlyand downwardly-extended flanges l8, and the corners of the article ll are angularly disposed and provided with widened flanges It. A pair of rigidifying flanges 20 extend across the flat plate 12 on opposite sides of theaperture l4 as illustrated. A downwardly-directed boss 22 projects from the lower surface of the plate l2 between the aperture I4 and one of the end flanges 16.-

Production pattern equipment may be formed from the pattern It as disclosed in my previously issued'Patent No. 2,348,086, issued May 2, 1944. The pattern It may be embedded in any suitable parting material such as molding clay, plaster, etc., up to its median plane. A female impression of the exposed portions of the pattern and the parting material may be formed in any suitable moldable substance such as alloys of the tinbismuth-antimony base, such for example as an alloy consisting of 42% tin and 58% bismuth, possessing the characteristic of flowing and solidifying with negligible change of volume, or plaster. The assembly may then be inverted, the parting material removed, and a female impression formed of the portion of the pattern initially covered by the parting material, and the exposed surface of the first female impression.

These complementary female impressions may be separated, the pattern removed, and the impressions used in the formation of production patterns. The patterns formed from the female impressions may be either of the plate tyne wherein separated complementary pattern segments are carried by separate plates, or of the matched plate type wherein the complementary pattern segments are disposed on opposite sides of a single plate.

Where matched plate patterns are to be formed, the female impressions may be mounted on-opposite sides of a pattern frame 24 illustrated in Fig. 4 and a pattern plate 28 having the complementary cope and drag pattern segments 28 and II respectively on opposite sides of the plate and suitable feeder, gate and riser chamber-forming members ll, 36, and SI respectively, formed by a casting operation as more clearly illustrated in my copending application Serial No. 465,234, flied November 11, 1942,.

The production pattern may be formed of any suitable moldable substance, such for example as white metal, an alloy of aluminum, the cerro a1- loys such as cerrobase, etc. If the substance of which the pattern is formed does not p the characteristic of substantially constant volume.

molds 52 and SI respectively formed between the cope and drag pattern members 28 and 30 and the cope and drag mold-forming members 48 and 50.

molds .52 and S4 with a progressively decreasing ratio of external surface area to the volume of the mold cavity toward the point of feed.

The temperature control molds 52 and 54 have fins 56 positioned adjacent and extending around the heavier or thicker sections such as the flanges l6, l8, and 20 to increase the external surface area of the mold adjacent these portions of the mold cavity to increase the heat-radiating capacity and accelerate the solidification of heavy or thick sections of the casting.

The molds 52 and 54 have thickened sections 58 adjacent light or thin sections of th mold cavity, such for example as adjacent the flat plate l2 of the pattern II to reduce the ratio of the external surface area to the volume of the mold cavity and retard the dissipation of heat by radiation. The increased mass of the mold-forming substance also retards the dissipation of heat because the cooling eifect of the mass of the mold by conduction is substantially in inverse proportion to the volume of the mold cavity.

The temperature control molds 52 and 54 are so shaped that the cooling eifect caused by radiation and conduction produces progressive solidification of the casting towards the feeder ill. controlled gate 62, and riser chamber 64 formed in the cope temperature control mold 52 by the feeder and riser-forming members 34 and 38 respectively of the pattern 26.

The light or thin sections of the casting and the supply of shrinkage compensating alloy or metal are thus maintained open until the heavier sections solidify, and progressive or substantially uniform solidification toward the point of feed occurs. The isolation of sections of molten alloy or metal from the feeder by solidified sections is thus avoided, and the introduction of shrinkage strains in the casting is prevented.

' The temperature-control mold-forming'members 48. and 58 have female impressions conforming with the desired external contour of the temperature control molds 52 and 54. These mold contour-forming members 48 and 58 may be made by a reproductive method from a master male model having the desired external contour of the temperature control mold in the manner set forth in my copending application Serial No. 455,862, filed August 24, 1942, and Serial No. 421,115, filed December 1, 1941. I

Where the contour-forming members 48 or 58 have a plurality of symmetrical or identical sections or segments, a male pattern of only one of these alike segments or sections need be made. A female impression of this male pattern segment may be formed by a reproductive method in suitable material, such for example as one of the cerro alloys possessing the characteristic of accurately conforming to the contour of the pattern and solidifying with negligible change of volume, or plaster.

The necessary number of male impressions required to form a complete male pattern for the mold contour-forming members 48 or 58 may then be formed by a reproductive method from the single female impression. These male segments may be assembled and used in the formation of any desired number of temperature control-forming members 48 and 58 having female impressions of the desired external contour of the tempera ture control molds 52 and 54. 1 The temperature control mold-forming members 48 and 58 may be formed in any suitable moldable substance, preferably possessing the characteristic of solidifying with negligible varia-' tion in volume, such for example as the cerro alloys. Compensation may bemade for change of volume in the event that the substance of which the mold-forming members 48 and 58 do not possess the characteristic of substantially constant volume upon change'from liquid to the solid state. The temperature control mold-forming members 48 and 58 may vary in shape and configuration through very wide limits. All that is necessary is that they meet with the pattern plate 26 with a suflicient degree of accuracy to confine the temperature control mold-forming substance to form the desired configuration. The outer contour of the temperature control mold serves no purpose other than to control the dissipation of heat and therefore need not be accurately formed. .After the pattern and temperature control mold-forming members have been formed they may be assembled with the flasks 48 and 42 in the relation illustrated in Fig. 5. Any suitable moldforming substance 88, such for example as gypsum, may be introduced through an opening 68 in the cope mold-forming member 48 to fill the space between the female impression of the temperature control mold-forming member 48 and thesurface of the pattern plate 26 and cope pattern members 28 to form the cope temperature control mold 52. p

A drag mold-feeding member I8 associated with the pattern plate 26 and interposed between the cope and drag flasks 48 and 42 permits the moldforming substance 56 to flow into the space between the drag mold-forming member 58 and the lower surface of the pattern plate 28 and the drag pattern 38 to form the drag temperature-control mold 54. v

The feeding member I8 comprises a pair of flat means members I8 positioned at spaced intervals may be employed. The sheets have apertures I4 adapted to align with an aperture I6 through the plate 28. After the mold-forming substance 55 has been introduced to form the cope and drag moldforming members 52 and 54, and has attained a predetermined set such that the molds may be separated from the pattern and former members, a handle I8 is actuated to move the sheets I2 across the aperture It in the pattern plate 25 to cut the mold-forming substance 86 between the cope and drag molds 52 and 54.

Where plaster or gypsum or other low heat conducting material is used as the mold-forming substance 85, suitable strengthening and rigiditying ingredients such for example as asbestos fiber may he added to provide desirable physical properties. The substance 58 is preferably applied in a semiliquid or plastic state, and if desired may have somewhat of an excess of moisture. When the temperature control molds 52 and 54 have attained a predetermined set they may be separated from the pattern and cope and drag mold-forming members and subjected to a drying or curing operation to dispel moisture therefrom.

If desired the temperature- control molds 52 and 54 may be removed from the flakes 48 and 42 either before, during, or after being subjected to the drying or curing operation. The treated molds 52 and 54 may be positioned in cope and drag clamping flasks 88 and 82 assembled in the .manner illustrated in Fig. 7 and used in the formation of castings.

It will be noted that the flasks 88 and 82 do not meet at the parting line between the cope and drag molds 52 and 54, but rather engage the tapered edges of the molds at points spaced from the median plane of the molds. Clamping pressure may therefore be exerted through clamping bolts 84 engaging brackets 85 and 88 of the cope and drag flasks 88 and 82 to hold the molds together during the pouring of the molten alloy or metal into the molds to form a casting. Guide pins 98 carried by the cope flask 88 may be provided to engage apertures 92 associated with the drag flask 82 to maintain alignment.

When the temperature-control molds have been formed and assembled in the manner illustrated in Fig. 7, molten alloy or metal may be introduced through the feeder 68 to fill the casting cavity. The temperature control molds dissipate heat at varying rates of rapidity from sections of varying contour of the casting to induce progressive solidification of the molten alloy or metal toward the feeder 68 to form a homogeneous casting free from shrinkage strains.

The embodiment of the invention illustrated in Figs. 9- to '12 is an adaptation of the invention to the formation of a plurality of castings in a single standard flask. This embodiment of th invention is illustrated as applied to the formation of temperature-control molds for. forming a seemental gear l88 having a hub I82 connected to a gear segment I 84 by a web I85. The web I86 is of considerably less cross-sectional area than the hub I82 and the geared segment I84 and is provided with a plurality of apertures I88 and a boss I I8 of thickened cross section.

Production pattern equipment of the so-called plate type may be formed from the unitary master pattern in the manner disclosed above and in my copending application Serial No. 421,115, filed December 1, 1941.

sheets I2 positioned to lie on opposite sides of the pattern plate 26. If desired, a plurality of feeder rality of pattern plates I I4 may be positioned in a standard plate flask H8 and attached thereto by means of screws H8. The flask II8 preferably has a removable baseplate I20 adapted to be aligned with the flask II5 by means of suitable dowel locators I22.

A temperature-control mold-forming member is shaped to lit the standard flask H6 and is provided for each of the cope and drag pattern and flask membersto provide a cope and drag temperature-control mold I24 having heat-radiating flns I26 positioned to overlie the heavier or thicker sections of the mold cavity to accelerate the dissipation of heat from these sections. The

mold-forming member has female surfaces shaped to cooperate with th pattern segments II 2 to provide thickened mold sections I28 adjacent sec-.

tions of light or thin section to retard the dissipation of heat from these sections of the casting as discussed above.

After the pattern and mold-forming members have been formed, they may be assembled, and the moldable substance introduced into the space between the former and pattern to provide the temperature control molds. Suitable looator means may be provided to align the cope and drag molds relative to each other preparatory to introducing the molten alloy or metal to form the casting. I

It will be apparent that dissimilar pattern members carried by the pattern plates II4 of standard size may be provided in the flask II6 of standard size. A plurality of castings of such. a size that a plurality of them may be formed in a single flask may thus be formed in temperaturecontrol molds formed in a single standard size flask to provide homogeneous castings free from shrinkage strains.

Figs. 13 to 16 show the adaptation of this invention as applied to the formation of temperature-control molds. from die patterns for use in the Capaco process of plaster molding.

Fig. 14 illustrates a diepattem formed of a standard flask I 50 having a plurality of pattemcarrying blocks I52, I54, and I56 carried by frames I53, I 55, and I51 respectively of accurate external dimensions secured to the base I58 by suitable screws I58. The space within the flask I50 may be filled with a plurality of patterncarrying blocks of the same or different size. The size of'the blocks may be graduated in multiples of a standard dimension so that the space within the flask I50 can be used to the greatest advantage.

The pattern-carrying blocks are formed to accurate external dimensions in three planes to insure proper alignment of the casting cavities formed in the cope and drag molds by the cope and drag pattern members. A pattem-carrying block may thus be selected to accommodate any size pattern member. The patterns I80, I62, and,

I64 may, for example, be carried by the'blocks I52, I54, and I56 respectively. The pattern and pattem-carrying blocks of accurate externaldimensions in three dimensions may be readily formed in the manner set forth in my copending application Serial No. 454,831, filed August 14, 1942.

A temperature-control mold-forming member I10 of the same external dimensions as the standard flask I 50 may be superimposed on the flask I50 and accurately aligned therewith by suitable locator means I12 and I14 carried by the moldiorming member I10 and flask I50 respectively.

The space within -the confines of the moldimpressions I88 to cooperate with the exposed surfaces of the patterns I60, I62, and I84 respectively, to provide therebetween a temperature control mold-forming cavity having external surface area and mass proportioned with reference to the casting cavity to provide substantially progressive cooling toward the point of feed of the molten alloy or metal introduced into the casting cavity formed by the pattern impressions I68, I82, and I64.

The assembled temperature control moldforming member I10 is superimposed on the.

standard sized flask I50 of the die pattern assembly and is aligned therewith by means of the locator members I12 and I14. Any suitable moldforming substance preferably of the low heat conducting type such for example as plaster is introduced into the flask I50 to flll the space between the blocks I16, I18, and I of the former I10 and the pattern impressions carried by the pattern blocks I52, I54, and I56 to form the temperature control mold I88.

It will be noted that the impressions no car-- ried by the mold former I10 are shaped with reference to the pattern impressions to provide flns I on the temperaturecontrol mold I 88 to accelerate the dissipation of heat from heavy sections of the casting cavities formed in the mold I88 by the pattern impressions I60, I62, and I64. The impressions I86 of the mold former I18 are also spaced with reference to the pattern impressions to provide mold-thickened sections I82 positioned to overlie lighter or thinner sections of the casting cavities to retard the-dissipation of heat by radiation from light sections of the casting to be formed, and to reduce the cooling effect caused by conduction by proportionately increasing the mass of the mold-forming sub-v stance.

The impressions I86 of the mold-forming blocks I18, I18, and I80 are preferably shaped with reference to the pattern impressions I88, I62, and I64 that upstanding walls I84 are formed along the marginal edges of the pattern blocks I52, I54, and I56. The upstanding walls I84 may be engaged to hold cope and drag temperature control molds together at the time molten alloy or metal is introduced into the casting cavities to form castings.

It will be understood that suitable feeder passageways extend along the die pattern to connect with each mold cavity to permit the introduction of molten alloy or metal into the casting cavities. These feeder passageways may be formed inthe mold by suitable feeder runners positioned on the die pattern at the time the mold-forming substance is introduced to form the mold,

The temperature control mold-forming members carried by the blocks I16, I18. and I88 may beformed by a reproductive method of any suit able'material, such for example as the cerro alloys, on frames of accurate external dimensions as set out in my copending application Serial No. 454,831, flled August 14, 1942.

When it is desired to change .a pattern to form castings conforming to a different pattern, all that isnecessary is to remove the pattern from the die pattern and the mold-forming member,

- After the formation of cope and drag tem ture control molds I88 and I98 respectively, they may be assembled as illustrated in Fig. 16 to provide casting cavities I98.

The drag mold I96 may be positioned on a plate 200, and a plate 202 may be positioned on the cope mold I88. Suitable locator means may be employed to accurately locate the cope and drag molds I88 and I 06 respectively to prevent misalignment of the casting cavities I88. Clamps may be provided to engage the plates 200 and 202 or a weight or other suitable pressure-applying means may be employed to prevent separation of the cope and drag molds when molten a1- loy or metal is introduced into the casting cavities to form castings.

If desired, directed air currents may be employed to facilitate cooling of all the temperature control molds disclosed herein to accelerate solidification of the molten alloy or metal. The temperature of the air may be controlled, and it may be directed over a portion only of a mold if desired to provide the progressive solidification of the castings. It will be apparent that the heatdissipating characteristics of the entire temperature control mold may be substantially uniform throughout and that currents of air or other cooling fluid preferably controlled as to temperature may be directed over the mold towards the point of feed and the shrinkage compensating supply of molten alloy or metal to provide the desired progressive solidification of the castings. Air or other fluid may be introduced into the space between the temperature control molds, and the plates 200 and 202 through suitable air inlet conduits 204 and 208 projecting through the plates 200 and 202 respectively. The inner surfaces of the plates 200 and 202 may be corrugated as illustrated at 208 and 2I0 respectively to permit the cooling medium to flow over the upstanding walls I94 to carry heat away from the temperature control mold associated with each casting cavity. The cooling fluid may be dispelled through outlets 2I2 and 2H extending through the plates 200 and 202 respectively preferably positioned at the opposite end of the molds, but illustrated as at the end of the third mold cavity. I claim: i 1. 'The method of forming cope and drag temperature control molds from a matched plate pattern and mold-forming members comprising interposing standard flasks between the matched plate pattern and mold-forming members, the mold-forming members being shaped with refa,sos,71o

e'rence to pattern impressions carried by the matched plate pattern to provide a temperature control mold having progressively decreasing heat dissipating characteristics toward a feeder, introducing a mold-formingsubstance into the space between the'cope mold-forming member and the cope pattern, the matched plate pattern having a controlled aperture to permit the mold- -Iorming' substance to be introduced into the space between the drag mold former and the drag pattern, severing the mold-forming substance at the controlled aperture in the matched plate pattern to separate the cope and drag temperature control molds, and separating the tempera- 3. A matched plate pattern having cope anddrag pattern impressions, and a controlled aperture extending through the pattern plate outside of the pattern impressions comprising cutting means adjacent the aperture and aligned with the cope and drag surfaces of the pattern plate.

4. The method of forming non-permanent temperature control molds comprising superimposing a mold former on a die pattern including a flask having aplurality of removable patter-ncarrying blocks of graduated sizes the mold former comprising a plate having a plurality of removable mold-forming members each shaped with reference to the pattern impression carried by its associated pattern carrying block'to provide a mold having heat dissipating characteristics substantially roportionate to the. volume or the pattern impression throughout, and intro ducing a mold-forming substance of low heat conducting characteristics into the space between the pattern-carrying blocks and the mold-forming members.

5. A temperature control mold former comprising a die pattern including a flask having a plurality of removable pattern-carrying blocks, and a closure for theflask having a plurality of removable mold-forming members each shaped with reference to the pattern impression carried by its associated pattern block to provide a nonpermanent mold formed of low heat conducting material having heat-dissipating characteristics substantially proportionate to the volume of the pattern impression throughout.

'6. The method of forming non-permanent temperature control molds of low heat conductin material in standard flasks between pattern and mold-forming members to provide cope and drag molds having bevelled side walls and heat dissipating characteristics substantially proportionate to the mold cavity throughout, separating molds from the pattern and mold forming members,

drying the molds, clamping cope and drag dried molds in casting flasks having guiding means and reversely bevelled side walls to engage the bevelled side walls of the molds to hold the molds in assembled relation, and introducing molten alloy or metal into mold cavities to form substantially homogeneous castings.

7. A non-permanent temperature control mold formed of low heat conducting material comprising cope and drag sections formed in die patterns having a flask and a plurality of replaceable pattern carrying blocks of predetermined graduated sizes to provide a mold having a plurality of casting cavities each having sections of varying crosssectional area and a single feeder for the introduction of molten alloy or metal into the casting cavities, the mold having progressively decreasing heat dissipating characteristics toward the feeder to insure progressive solidification of molten alloy or metal in each casting cavity toward the feeder to provide substantially homogeneous castings.

8. The method of casting comprising forming non-permanent cope and drag temperature control molds of low heat conducting material in die patterns including a flask and a plurality of replaceable pattern carrying blocks of predetermined graduated sizes and having a feeder and a plurality of casting cavities of varying crosssectional area, the mold being of substantially uniform thickness between casting cavities and contoured adjacent casting cavities to provide heat dissipating characteristics substantially proportionate to the casting cavities throughout, assembling cope and drag temperature control molds between corrugated plates, introducing molten alloy or metal into the casting cavities, and directing cooling fluid through the corrugations of the plate towards the feeder to progressively cool the molds towards the feeder to provide substantially homogeneous castings,

9. The method of forming cope and drag molds from a matched plate pattern having cope and drag pattern impressions and a controlled aperture extending through the pattern plate outside of the pattern impressions, assembling the matched plate pattern with cope and drag flasks, introducing mold-forming substance into one of saidflasks to fill the cope and drag flask, and separating the cope and drag molds from the pattern.

10. A temperature control mold former for a die pattern including a flask having a plurality of removable pattern carrying blocks of graduated sizes comprising a closure for the flask having a plurality of removable mold contouring members of similar graduated sizes, each of the mold contouring members being proportioned with respect to the patternimpression carried by its associated pattern carrying block to provide a non-permanent mold formed of low heat conducting material wherein the mass of the mold forming substance varies substantially in inverse proportion to the cross-sectional area of the pattern impression throughout.

'11. A temperature control mold former for a die pattern including a flask having a plurality of removable pattern carrying blocks of graduated sizes comprising a closure for the flask having a plurality of removable mold contouring members of similar graduated sizes, each of the mold contouring members being proportioned with respect to the pattern impression carried by its associated pattern carrying block to provide a non-permanent mold formed of low heat conducting material wherein the cooling efiect of the mass of the mold and its external surface area are proportioned throughout with respect to the crosssectional area of the pattern impression to permit rapid dissipation of heat from heavy sections of the casting to be formed and to retard the dissipation of heat from light sections of the casting.

RAYMOND J. MILLER.

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