US2299016A - Mold and mold form - Google Patents

Description

Oct. v13, 194:2.'v H. F. HAGEMEYER 2,299,016

' MOLD AND MOLD FORM I Original Filed Juge 14, 1938 2 Sheets- Sheet i 3 'C122 E +13 :,21v I l 11kg@ 20 g D 13 z2 t 10 l l 1 W@ l Y//A/////// L E 1 710 '12 l v I Oct- 13,1942- i `l-l. F. HAGEMEYER 2,299,016'

. MLD AND MOLD FORM A Original 'Filed June 14. 19,38 2 Sheets-Sheet 2 Zyl/,2.

iQ-vga @ya W2-P v ndex/Z071 ffqgmgef Patented Oct. 13, 1942 MOLD AND MOLD FORM Henry F. Hagemeyer, Chicago, Castings Patent Corporation, corporation of Illinois IIL, assignor to Chicago, 111.', a

original' application June 14, 193s, serial No.

1940, Serial N0. 328,215

Claims (Ci. 2z-.113)

My invention pertains to molds for use in making metal castings. of my copending application Serial No. 213,595, filed Jue 14, 1938, and entitled Molds and mold forms.

In conventional casting practice, where a con- 'Ihis application is a division tinually charging variety of castings is made in small lots, the match plates used for only one job and then discarded are a source of considerable expense.A Such match plates are relatively costly because they must be machined accurately to provide a true parting surface on each mold section. Heretofore it has been customary to aiilx the individual patterns directly to the match plate, so that it can be used with no other pattern group and becomes obsolete when the run of its particular group of castings is completed, because of the holes drilled -therein to receive screws for securing the patterns to it. It is extremely infrequent'v that a repeat order'I will be received at the same time, for equal quantities of all castings corresponding to the patterns on a match plate. A choice must be made, therefore, between devoting a whole match plate to one type of pattern, which usually is not warranted by the quantity of units required, or by shifting patterns for castings a larger number of which is required to new match plates with a different pattern assembly, when the quantity of castings corresponding to some of the patterns on the match plate has been made. The old match plates are then discarded and the patterns whose jobs are finished are removed from such match plates andstored.

I have devised a match plate assembly which employs a plurality of individual pattern plates, each carrying a pattern, which may bev assembled in parquet fashion on a base plate. These unit pattern plates are all of the same size, or in size a simple multiple of the smallest pattern plate, so that a selected group of such plates can be assembled onto a base plate of standard size adapted to accommodate a predetermined-'number of unit pattern plates of the smallest size. Such assembly will, of course, exactly cover the entire pattern plate receivirg surface of the base plate,

A further diiliculty arises in conventional practice inthe assembly of the mold sections, Occa'' sionally there are parts of a mold section projecting beyond the general plane of the parting surface; f or example, there may be dowels of a dowel and socket registering arrangement. When the mold sections .are being placed together the parting surfaces are hidden from view,and it is diiiicult totell whether the corresponding parts of the sections are in exact registry as the sections Divided and this application April A6,

approach each other. Mold material, such as that of the gypsum base type, :for example, is quite fragile and if a projecting part of one mold section is not in precisealignment with its complemental recess in the other mold section, either the projection, or the surface of the other mold section accidentally struck by such projection, or both, may be damaged. Even an injury only to a dowel may be serious, for its purpose is to prevent misalignment of the adjoining mold sections so that an accurate casting, rather than a lopsided one, will be produced by the metal poured into the mold cavity.

To insure accurate positioning of the mold sections during the assembling operation, I have devised registering elements for their edges which may be engaged by a suitable guiding device prior to contact of their parting surfaces; This mechanism will guide the movement of the mold s ections as they approach engagement and -preferably also will support at least 4one of such sections during such operation. The registering element may consist of ribs, one on each of two opposite edges of each mold section, lar to ,the parting surface and so disposed 'that the cope ribs will be aligned with the drag ribs when the mold sections are assembled. The cope ribs may be provided with shoulders intermediate ktheir-ends which may be employed in supporting the cope.

mold form tovform metal receiving mold cavities,

A further consideration in the design of my and mold is to provide means for eliminating the dns on the castings, and also on' the feeders for the molten metal, such as the runv xner and gates. For this purpose I provide a groove about each mold cavity pattern to producel -a sealing ridge along the margin of each moldcavity. By the term mold cavity pattern I refer to all patterns on the match plate which serve including the runner pattern strip. gate pattern strips, sprue pattern post, in addition to those patterns which form the cavities for production of the useful castings. 1

'I'he principal object of my invention, therefore, is to provide a match plate assembly having a plurality of interchangeable pattern plates all of'a uniform size, or thesize of each of which is'.

smallest pattern'plate.-

a simple multiple of the which may be assembled to. cover a base lparquet fashion.

yl'i further object is to provide such a match plateA assembly in which the runner and sprue Plate in v cavityforming portions of the pattern need not and preferably also the patterns for extending perpendicuand sections will remainxed when the pattern plates are interchanged.

Still another object is to provide -means for forming on the mold sections during the molding operation registering elements for use in guiding complemental mold sections while they are being assembled to form the complete mold.

A further object is to provide means for pre- I venting the formation of fins on the useful castings and also on the feeders, such as the runners and gates.

Additional objects, and especially those resulting from the particular construction of my flask and match plate assembly, will be understood from a study of the following detailed description in conjunction with the. accompanying drawings. I have illustrated a ask rim or ring and match plate assembly which I have found to be practical, but obviously many variations may be made in its structural details within the spirit of my invention as dened in the claims appended to this specification.

Fig. l is a plan view of the cope nasi: rim and match plate assembly showing a representative casting pattern mounted on a pattern plate.'

Fig. 2 is a'transverse section taken along line 2 2 ofvFig. 1.

Fig. 3 is a fragmentary longitudinal section taken along line 3 3 of Fig. l. y

Fig. 4 isl a fragmentary longitudinal section taken along line (fi-d of Fig. i.

Fig. 5 is a fragmentary transverse section taken along hne 5 5 of Fig. 1. i

Fig. 6 is a fragmentary longitudinal section corresponding to Fig. 6.-, but illustrating the drag ask rim and match plate assembly.

Fig. 7 is a fragmentary transverse section taken' along hne 'll- 1 of Fig. 6.

Fig. 8 is a fragmentary central longitudinal section through assembled cope and drag moid sections.

Fig. 9 is a fragmentary transverse section at the position of line Ill- I0 of Fig. 8, showing the mold sections just prior to their engagement.

Fig. 10 is a fragmentary' transverse section through assembled cope and drag mold sections taken along line AIIL-Ill of Fig. 8.

Fig. 11 is afragmentary perspective view 4oi. the drag mold section showing the projecting rib used to assist in guiding it during the. operation of assembling the cope and drag mold sections into the complete mold.

Fig. 12 is a plan view of a representative cast'- ing.

Fig. 13 is an elevation View of the casting of Fig. 12.

Fig. 14 is a. fragmentary plan view of one mold section employed in forming the casting of Fig. 12.

Fig. 15 is a transverse section taken on line4 I5--I5 of Fig. 14. Y

Fig. 16 is a fragmentary transverse section tak. en on line It-I6 of Fig. l, and showing the pa-ttern employed in forming the mold section of Fig. 14. l

Fig. 17 is an Venlarged fragmentary section through cope and drag mold sections showing complemental sealing ridges just prior to their `engagement during the operation of assembling the mold sections.

Fig. 18 is 'a fragmentary section through-cope' and drag mold sections showing they sealing ridgesof Fig. 17 after being pressed into engagement.

' forming dowels and dowel sockets for the mold Fig. 19 is a fragmentary section through conventional cope and drag mold sections in the region of a mold cavity edge just prior to engagement of their parting surfaces during the operation of assembling the mold sections.

Fig. 20 is a fragmentary section similar to Fig. 19 showing the parting surfaces pressed into engagement.

Fig. 21 is a fragmentary se'ction through cope and drag mold sections similar to Fig. i7, but showing a modified form of sealing ridge.

Fig'. 22 is a fragmentary section through that portion of a match plate-and pattern employed to forinon a mold section a sealing ridge like that shown in Fig. 2l.

Fig. 23 is a fragmentary section through that portion of a match plate and pattern for forming a still further shape of sealing ridge.

Fig. 24 isa fragmentary section through cope and drag mold sectionsl similar to Fig. 1'7, but showing the sealing ridge on only one mold section. V

In the match plate and flask assemblies shown in Figs. 1 to 7, inclusive, the .individual pattern some useful casting pattern P, are mounted in y parquet fashion on a base plate i, which extends preferably beyond all the elements assembled thereonl Thus the entire pattern plate receiving area of base plate I will be covered by edge-ad-r joining pattern plates. These pattern plates may all be uniform in size, or if larger plates are re- `quired to accommodate certain patterns, they may be made double the size of the smallest plate iii, as indicated by ID', or the size may be even three or four times the size of the minimum plate. Preferably the length of all the plates between the center plate I I anda marginal plate.I2 is the same, although the widths of different sized plates, parallel to thecenter plate II, may vary in simple multiples of the width of the narrowest plate. These pattern plates may, therefore, all be said tofbe in width a. simple multiple of the smallest plate size, the term simple multipie including unity, to embrace the situation where all the plates are of the same size.

On each pattern platev will be mounted permanently a useful casting pattern, and when the presently required number of molds have been 'stituting operation. ,The flask rim and match plate structure is such that evena complete interchange of the individual pattern plates may be made without disturbing any of the uniformly necessary elements such'as the flask rim, sprue post, and main runner pattern, which remain permanently secured to the base plate i.

Moreover all pattern platespf the same size are provided with uniform .meansfor securing them to the base plate I, which may consist of dowels I3 carried by two diagonally opposite corners of the pattern plate and engageable in holes formed in the base plate I. Into the other diagonally opposite corners may be screwed bolts I4 extending through the base plate I which is recessed to receive the bolt heads. A further simillax; holding bolt may be provided at'the center of each pattern plate. The disposition of the dowand both ends of which els and bolt receiving apertures will. of course, correspond on each of the pattern plates no matter what the plate width may be. In each of the various pattern plate positions of the base plate I the screw and dowel holes will be arranged in the same relative positions.

The center plate II and the marginal plates, I2 may be permanently secured to the base plate I in any suitable manner. A ilask rim or ring 2 may also vbe secured in permanent relationship to the match plate, preferably resting on the marginal plates I2. n the center plate II a runner pattern strip I5, shorter-than the center plate, is mounted, which'may be the same shape and size for both the cope and drag match plates, stop short of the rim 2. I prefer, however, that the runner pattern'in the cope match plate be higher than that in the drag match plate, to allow any dross which may flow into the runner cavity to accumulate in the upper portion thereof above branch gatesl provided in the cope mold section. In the cope match plate a sprue pattern post I5 is also provided, preferably located at one end of the runner pattern I5. The runner pattern of the drag also has a sprue pattern projection I1 which produces a sprue 'sump '1n the drag section of the mold immediately belowv the sprueaperture in the cope section of the mold.

Between each end of the center plate II and the adjacent end of the runner pattern I5, I provide means constituting arpattern for either the dowel or the socket of a dowel and socket mold section registering device. Preferably in the cope match platea boss I8 is provided to serve as a pattern for forming a dowel socket in the cope mold section. In the drag match plate assembly, on the other hand, will be provided a cup I9, of slightly less depth'than the height of boss IB, serving as a pattern for a dowel complemental to the dowel socket formed in the cope mold section. It will, therefore, be seen that the patterns for forming the dowel registering mechanism, the runner cavity, the sprue aperture, and the sprue sump are all permanently secured lto the base plate I, and are entirely separate from and mounted independently ofthe interchangeable pattern plates I0 and I0. n

The manner in which the cope and drag mold sections iit together is illustrated in Fig. 8, in which the cope section C is provided with thev sprue aperture I6' and a portion of the runner cavity I5', whereas .the dragsection D has the sprue sump I1', located immediately below the sprue aperture I6', and the remainder of the runner cavity I5', The sprue aperture and sumpI as well as the portions of the runner cavity and complemental mold cavities formed in other portions of the cope and drag, are held in registry by the dowels Il' of the drag seated in the dowel sockets I8' provided 1n the cope. The purpose of the sprue sump l1 is to prevent the molten metal from rushing violently and in a pulsating fashion into land throughthe runner cavity Il', and from there into the useful casting forming portions of the mold cavity. As the metal ows through the aperture I8 into the sprue sump I'I'I its inrushing force is somewhat absorbed by the impact and turbulence therein, and its flow becomes consolidated and smooth as it enters thel runner cavity.

After each mold cavity corresponding to a useful casting has been filled with molten metal it' is desirable to provide -a reservoir of metal from which the metal of the casting may draw as it' shrinks during the process of solidication and cooling, and which reservoir willremain liquid ,until such action is substantially complete. If no source of molten metal is provided, from which the deciency caused by such shrinkage may be made up, excessive strains will be set up in the final casting, and a strong, solid casting may not result. For convenience the reservoir of molten metal should be the feeders, namely, the gates, the runner, and the sprue, all of which should be of suilicient size and of proper shape to remain liquid and to supply metal to rell all the casting mold cavities as the metal therein progressively 'shrinks in solidifying and cooling. In order to maintain all these feeders in a liquid condition, theoretically their surfaces, which radiate heat, should be kept to a minimum. Their cross sections should, therefore, be circular, but since it is inconvenient to make these feeders precisely cylindrical while making them large enough, at least their corners should be rounded as indicated in the runnerv cavity I5' of Fig. 8.

The heat radiation of anyl such feeder will be greatly increased, which will correspondingly in- -crease its' cooling rate andhasten solidification, by the formation thereon of a fine between the parting surfaces of adjoining mold sections.

Such fins frequently occur on the runner and gates which are almost invariably located at the parting surfaces. The crevice in the seam formed by the junction of the parting surfaces along these feeders, as shown in Fig. 20, I have found can be sealed by the provision of a sealing ridge 3 as shown in Fig. 9. Such ridge is produced by forming a groove 3' along the sides of the patterns forthe feeders, such as the gate pattern strip G and the runner pattern strip I5.

In the preferred construction, the groove 3' for the gate pattern strip G is formed directly in the pattern plate I0, on which such strip is mounted, depressed below the surface of such pattern plate. A marginal groove 3 may be formed along the runner pattern strip I5 between each side thereof and the adjacent edgeof a pattern plate merely by making the-longitudinal edges of center plate II of a thickness slightly less than the thickness-of the abutting pattern -plate I0 or I0'. The action of the sealing ridges 3 is illustrated in Figs. 9 and l0, the former figure showing the cope and drag mold sections C and D, respectively, just prior to engagement of their parting surfaces,.while Fig. l0 shows the saine portions of the cope and drag sections after their panting surfaces have been pressedv into engagement. Eac'hg'roove 3 may 4advantageously be approximately one-sixteenth of an inch in width and three-thousandths of an in-ch in depth, so that. the sealing ridges 3 will .be approximately one-sixteenth of an inchv in width and threethousandths of an inch in height. The mold material is preferably of a crushable nature such, for example, as of gypsum base, so that when theparting surfaces are pressed together, the

sealing ridges will be engaged before the remainder of the parting surface comes into contact, and their crests will be forced inward and y deformed until theylie substantially in the-.plane -of the parting surfaces. This operation will prostill another shape.

It is also desirable in many instances to provide a similar sealing ridge about part or all of the cavity in which the nished casting is to be formed. The sealing action of the ridges is the same here as when provided along the feeder cavities, but, the considerations making elimination of the iin desirable are different. Unflnned feeders, as has been pointed out, have less radiation surface and hence are less susceptible to chilling and rapid solidiiication, so that they will remain liquid until the metal forming the iinished castings has solidified and cooled. Fins on usable castings, however, are undesirable because eXtra grinding or machining of such castings is required to remove them during the finishing operation. A representative sample of an unfinned casting is shown in Figs. 12 and 13, and one section of the mold used in the casting operation therefor is illustrated in Figs. 14 and 15. Figs. 1 and 16 show the pattern P by which the moldfsection of Figs. 14 and 15 is formed. In the pattern plate iii, encircling the pattern F, or in the inserted pattern block, as shown in `Fig. 16, is

` provided a marginal sealing ridge pattern in the form of a groove 3 by which the sealing ridge t for the castingcavity is formed on the mold. In

Fig. 14 are also shown the ridges 2 along the sides of the gate cavity G.

A comparison of the engagement of the sealing ridges and the engagement of conventional parting surfaces adjacent to a mold cavity is illustrated in the contrast of Figs. 17 and i8 with Figs. 19 and 20, these figures being much enlarged. A conventional pattern mounted in a match plate ordinarily has a slight fillet about its base, so that the parting surface of a mold section meets the adjacent side of a mold cavity in a slight arc. As a result, when the mold sections of Fig. 19 have their parting .surfaces broughtinto engagement, as shown in Fig. v20, a slight recess or crevice is formed into which the metal flows as it lls the mold cavity. The wedging action ofthe molten metal entering this crevice tends to force the mold sections apart, allowing a sheet of metal to flow between the parting surfaces, and thereby producing a fin. On the other hand, even though the parting surfaces of sealing ridges 3 of Fig. 17 may form an arcuate junction with the adjacent sides of the mold cavity, when these ridges are pressed together, as shown in Fig. 18, the crushable material will be deformed and forced laterally to fill up any crevice at the junction between the parting surfaces. Hence the `metal flowing into the cavity has no matrix for the formation of an entering wedge between the contacting parting surfaces of the mold sections.

It is not necessary that the sealing ridge have a flat crest such as shown in Fig. 17. An alternative form is illustrated in Fig. 21 having the crest of the ridge substantially in prolongation of the wall of the mold cavity. 'I'he ridge then slopes from this crest away from the mold cavity to merge with the main parting surface. Fig. 22

c illustrates a portion-of a mold cavity pattern having a marginal pattern provided with a groove of a shape to form the sealing ridge of Fig. 21. Fig. 23 shows a pattern for forming a sealing ridge of In both of these latter shapes the compression of the mold material will be greatest at the side of the ridge adjacent to the mold cavity, as the mold sections are pressed together.' It is not even always necessary that the sealing ridge be formed on the parting surfaces of both the cope and the drag, for a ridge on one parting surface only, as shown in Fig. 24,

may be sumcient. Especially if the cavity for a casting is formed entirely in one mold section, the other section having an unbroken parting surface extending on both sides of the sealing ridge, as indicated by the broken line showing of Fig. 24, a single ridge is sufficient. It is merely necessary that the material of the sealing ridge or ridges, when crushed, fill any crevice between the parting surfaces of the mold sections and pack suiiiciently tightly-at their junction to prevent any metal owing from a mold cavity outward between them.

Especially whenl the parting surfaces of both the cope and drag mold sections are provided withmutually engageable sealing ridges, it is extremely desirable that the mold sections be so disposed in registry prior to their assembly'that there will be no lateral movement of the parting surfaces and ridges at the time of their contact, causing rubbing which would tend to fracture and perhaps shear off into the mold cavity a portion of the ridge material, which would contaminate the metal poured into the mold cavity. Some provision should, therefore, be made to confine the mold sections to strictly linear movement as their parting surfaces approach each other during the assembling operation. For this purpose I provide mold section registering elements on each mold section, such, for example, as the ribs 4 formed on each end of each mold section generally perpendicular to their respective parting surfaces, as shown in Figs. 8 and 11. Preferably each rib, immediately adjacent to the parting surface of the mold, has a portion 40, provided with side and end faces in planes precisely normal to the parting surface, the two side faces, moreover, being parallel. The ribs are complementally located and aligned so that the side' and end surfaces of the portions 40 on the respective ends of the cope and drag mold sections are in coplanar relationship. Between the portion 40 'of each rib 4 and the flared portion 4| thereof, a shoulder 42, projecting beyond both the sides and end of the portion 40, is provided, which should be of suflicient Width to enable the mold section to be supported by a device only in engagement with such shoulder. As the mold sections approach each other, therefore, suitable means should be provided to maintain the sides of the portions 40 on the corresponding cope and drag ribs 4 in coplanar relationship as 'the parting surfaces are brought into engagement.

A convenient method of forming the ribs 4 is to provide pattern recesses 20 in the wall of the flask ring or rim 2. To increase the accuracy of the registering operation, the sides of the portion 40 of each rib 4 should be formed to precise dimensions and shape. These factors may be more easily controlled if the recess in the flask yis provided with a separate pattern block 2| accurately iiask rim 2 is provided with a notch in its lower edge of proper width and depth to fit snugly over the pattern block 2 I. For forming the portion 4| yof each rib 4 of a size to leave the intermediate shoulder 42 between the ends of the rib, the portion of groove or recess 20 in the flask rim proper remote from the base plate should be wider and deeper than the groove 22 in the block 2l, but should be in alignment with such groove. When located in proper lateral relationship by the blocks 2l tted within its grooves the flask rim 2 may be secured permanently to the base plate I by any suitable means. As is evident from Fig. l, I

the pattern plates I0 or l0 may be removed from .t or inserted into the match plate assembly Without removing the iiask ring ordisturbing the location of the blocks 2| which are secured to the marginal plates i2.

Having described the preferred embodiment of my invention, what I claim as new and useful and desire to protect by United States Letters Patent,

1. A mold section having a metal receiving cavity below the generally plane parting surface thereof, and -a slight crushable ridge upstanding above the lparting surface and extending along the peripheral edge of such cavity, said ridge adapted to be crushed when the mold is assembled to form a portion of mold material of greater density.

2. A` mold section having a metal receiving.

cavity below the generally plane parting surface thereof, and a slight crushable ridge having a flat crest substantially parallel to such parting surface and of much greater width than height upstanding above the parting surface and extending along the edge immediately adjacent such cavity, said ridge adapted to be crushed when the mold .is assembled to form a portion of mold material of greater density.

tending along the peripheral edge of such cavity,

and said ribs being adapted mutually to crush v each other toform a section of mold material of f greater density when said mold is assembled.

4. A mold comprising a pair of cooperating mold sectionswhich when placed face to face enclose a mold cavity, and means to prevent the formation of a iin at the parting line between said sections, comprising a ridge formed as a portion of at least one of said sections and extending beyond the parting surface thereof, said ridge out'- lining said cavity,' said'ridge being adapted to be crushedvhen the parting surfaces of said sections arev brought together, and said crushed ridge vforming a. portion of.l mold material -of greater density than adjacent mold material,

5. The method of preventing the formation of a n at the parting line of a casting which comprises forming a mold having a casting impression therein, forming a ridge on said mold outlining said casting impression, and crushing said ridge while assembling said mold to provide a mold portion of greater density at the mold parting line.

-HENRY F. HAGEi/mirm

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