US1679860A - Mold for casting metals - Google Patents

Description

' I M. GUYOT MOLD F03 CASTING METALS Original Filed April 13, 1925 2 Sheets-Sheet. l

INVENTOR BY $4.1 4. Mm

Mb ATTORNEYS.

Aug. 7, 1928.

M. GUYOT MOLD FOR CASTING METALS 2 sheets sheet Original Filed April 15, 1925 M INVEIgOR W (0mi H 6 ATT RNEYS,

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retinal Au 7, 1928.

UNITED STATES MARIUS GUYOT, F CLEVELAND, OHIO,

ASSIGNOR TO ALUMINUM 'COMPANY 01! .MMERICA, 0F PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

Morin non cnsrrne nrnrats.

application filed April 13, 1925, Serial No. 22,590. Renewed February ea, 19%.

This invention relates to multipart permanent molds for casting metals having melting points as high as or higher than aluminum and its alloys.

llt also relates to a multiple part mold for casting metals which is provided-with means to maintain the original alignment of unequally heated, cavity forming, hinged mold parts under different conditions of temperature.

' lt also relates to a mold for making a plurality of metal castings which is provided with a plurality of removable core pins and means for reciprocating a plurality of said p lt further relates to a compound gate having a common inlet passage for a multi ple mold for casting high melting point metals having a. high crystallization shrinka e.

llt further relates to a new and improved mold base for a permanent mold having two mold halves and a plurality of casting cavities therebetween.

the drawings attached to and forming a part of this specification in which one form of apparatus embodying the present invention is shown- Figure 1 is a top plan View of a multiple piston mold.

Figure 2 is aside view partly in elevation and partly in section taken on line 2-2 of Fig. 1.

Figure 3 is a sectional view taken on line as of Fig. 1.

Figure 4 shows in detail the core pin actuating mechanism, and

Figures 5 and 6 are respectively longitudinal and transverse sectional views of a slightly modified mold base.

The mold herein illustrated consists of a mold base indicated as an entirety by the character 1, made up of a bottom member 2 and a top member 3. Although members 2 and 3 may be variously connected, even in some cases being integral, I prefer to form them separately, as shown in the drawings, and secure them together by securing means, such as cap screws 4:. As shown in Fig. 2, the base members 2 and 3 are spaced apart and the top member 3 is provided with two holes 5 through each of which projects a pilot 6' which is capable of limited movement therein. The lower end of the pilot 6 ,rests on the top surface of bottom member 2 and has an outstanding shoulder 6 or flange to prevent removal of the pilot from opening 5. llt will be observed that the openlng 5 is somewhat larger in diameter than the diameter of the part of the pilot which passes therethrough so that pilot 6 is free to move in the mold base 1 to a limited amount. The top surface of the pilot 6 is preferably larger than the casting cavity of which it forms one end wall. .Through the center of the pilot 6 a hole I is provided which, when fitted with a plug 8 having a serrated outer surface, is adapted to permit the escape of air from the bottom of the casting cavity as the molten metal enters. This opening 7 may alsdbe utilized to form a machining boss on the end of the casting.

Alt one end of the mold base 1 is provided an upstanding hinge pin 9 which is removably fixed to the mold base by a nut 10 V which clamps the mold base 1 between the shoulder 11 on the pin and the nut 10. Two cooperating mold halves 12 and 13, which are alike in substantially all particulars, are

hinged at one end to the pin 9 and rest on arm 16 secured thereto as byv a cap screw 17. j

The end surface 18 of the arm 16 is preferably a cam surface so that when it engages with the adjacent outer "surface of the mold half 12 or with a wear plate 19 secured to such surface, locking pressure may be exerted on the mold half-:12 to bring the two mold halves together. Arm 16 when released from looking engagement with mold half 12 may be lifted, carrying with it the locking bar 14, and then used to move the mold" half 13 away from the mold half 12. A handle 20 secured to mold half 13 may be i The lower surfaces of the mold halves are cut away as at 12 and 13 to receive the parts of pilots 6 which project above the-top The mold halves.

surface of member 3.

however, closely engage the pilots when i locked together and align the pilots with re- Spect to the other walls of the casting cavities at the various temperatures of the casting operations.

The adjacent faces of the mold halves 12 and 13 are suitably recessed to provide gate, riser and casting cavities therebetween, there being in the mold illustrated herein two casting cavities 22, each provided with a main riser cavity 23 and an auxiliary risercavity 24:. The auxiliary risers 24 are located between the respective casting cavities 22 and the adjacent ends of the mold halves while the main riser-cavities are positioned between the casting cavities 22. A compound gate serves to conduct molten metal simultaneously into the adjacent riser cavities 23 and casting cavities 22. Briefly it comprises a common inlet passage, a feeder closely adjacent to and 1n communication with each of the casting cavities through. ashort narrow passage and a smoothly curving con necting passage of decreasing cross sectional area extending from the inlet passage to each feeder, these connecting passages each being shaped to form a liquid se.l when molten metal is introduced into the inlet pas=age and to conduct molten metal into the feeder cavity smoothly, and at a. rate of speed such that the stream of metal is not broken or agitated suificiently to result in the formation of a porous casting. The gate as illustrated herein comprises an upright inlet 25 and two sinuous control passages 26 which lead from the bottom of the inlet passage 25 upwardly and outwardly away from each other, then curve and extend downwardly and toward each other, and finally curve downwardly and away from each other in a wide sweeping curve, spreading out into a vertically elongated narrow fan shaped passage 27 which communicates with the adjacent 'riser cavity 23 through a narrow opening. The walls of each passage 26 converge downwardly to the point where they spread out into the narrow fan shaped passage 27 and cooperate to retard the velocity of the molten metal therethrough so that the metal enters the feeder and casting cavities smoothly and at such avelocity that substantially all agitation or splashing of the molten metal is avoided. Passages 26 extend upwardly above the bottom of inlet 25 and form a liquid met-a1 seal which assists in excluding light impurities from entry into the casting cavity.

The riser cavities 23and 24: communicate with the casting cavities 22 through vertically elongated narrow openings 23 and 24: of the general size and proportions illustrated, disclosed and claimed in U. S. Letters Patent No. 1,296,594 issued March 4, 1919, to Allen B. Norton.

Main cores designated as ent-ireties by the characters 28 and each consisting of a plurality of parts, in this instance three parts, extend into the casting cavities 22 to form the inner walls of casting cavities for internal combustion engine pistons and are supported in position therein by engagement of outstanding flanges 29 on the outer 'ends of the cores with the top surface of the mold halves 12 and 13. These cores are positioned in the casting cavities by keys 29 on the mold halves which engage the key- Ways 29 in one of the core sections and the assembled cores are held assembled when the mold halves 12 and 13 are clamped together and about the cores.

Each casting cavity 22 is provided with two core pins 30 which project thereinto to provide cored-out wrist pin bosses on the piston casting. These core pins 30 areoppositely disposed and in substantial alignment with each other, and the pins 30 in each mold half may be reciprocated simultaneously by actuating means consisting of a shaft 31 having a lever secured to it midway between its ends, and provided with suitable bearings 33 which are fastened to the respective mold halves as by cap screws 34, and also provided at each end of the shaft 31 with pinion gears 35. The pinion gears 35 are adapted to engage with blocks 36 secured to each of the core pins 30 as by removable pins 37, the under surface of each block 36 being provided with a rack 36 corresponding to the pinion 35. When the arm 32 is moved toward or away from the mold halves it will cause the shaft 31 with the pinions 35 to rotate thereby reciprocating blocks 36 and pins 30. In the outer ends of blocks 36 are secured handles 38 for use in removal 01 the core pins from engagement with the mold halves, should this become desirable, as for example, to cool the core pins. Since the rack on the underside of blocks 36 extends across the entire lower surface thereof, it will be understood that the pins may be readily removed without disturbing any mold parts. Each lever 32, with it; shaft 31, is adapted to reciprocate the core pins 30 in one mold half for each of the casting cavities 22. It will be understood that in this manner one operator can withdraw or assemble the four core pins by a single sin'lultaneous move of his two hands.

Each mold half 12 and 13 is of approximately uniform thickness, between the casting cavities as well as at the points where the core pins 30 enter the latter. as will be noted by reference to Figs. 1 and 3. Means are provided in the mold halves however to support the core pins suitably comprising steel bushings 39 each of about the same length as the thickness ota mold half and an integral flange 40 to seat against the outside of the mold half and be secured thereto as by cap screws 4-1..

The mold halves 12 and 13 are of unique lln - No. 22,549, filed April 13, 1925, of Allen B.

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Norton and Marius Guyot, and Serial No. 22,766, filed April 13, 1925, of Marius Guyot and Allen 18. Norton. 'lhese present mold halves are fixed to the mold base at one end and hence tend to expand in a longitudinal direction during the casting operation which expansion can take place only from the pin 9 toward the opposite end of the mold,

halves. It will beobserv-ed that this expansion although perhaps amounting to only a few thousandths of an inch, would be sutficient to create a misalignment of the mold parts with respect to the mold base, unless the mold base can be made to expand at substantially the same rate and to substantially the same amount as the mold halves or unless other means are provided for maintaining the original alignment of the walls forming the casting cavities. The means herein disclosed for maintaining the original alignment of such mold parts includes the movable pilots 6. Aszthe mold halves 12 and 13 tend to expand lengthwise, the pilots 6 are moved in the mold base 1 by recesses 12 and 13 in the mold halves which cooperate with the pilots to position them properly with respect to the casting cavity, thereby maintaining the original alignment of pilots and mold halves under all operating temperatures and conditions of the molds.

ln lBigs. and 6 is illustrated a modified form of mold base, didering slightly from the base shown in Figs. 1, 2 and 3. This modified base consists of a bottom member t5 similar to member 2 and two top members 46 similar to top member 3 is split lengthwise, each secured to the bottom member to as by cap screws (not shown). Pilots lSot any desired size or shape maybe retaiped between the members and 46 for limited movement to correspond with longi: tudinal expansion of the mold halves.

Having thus described my invention, what 1 desire to secure by Letters Patent is defined in what is claimed, it being understood that various'changes in the apparatus above described, not amounting to invention are considered as falling within the scope of this invention as defined by what is claimed.

What is claimed is: v

1. mold having a plurality. of casting cavities comprising a mold base, two hinged mold halves fixed at one end thereof and adapted to be moved on the mold base, and pilots movable in and extending above the top oi the mold base, the top surface of each of the said pilots cooperating with ad jacent surfaces of the said mold halves, to term a casting cavity.

2. In a mold having a plurality of casting cavities the combination of a mold base, hinged mold halves fixed'on the base and pilots movably carried by the base and co operating with the mold halves to form the casting cavities.

- 3. A permanent mold comprising a mold base, two hinged mold halves movably mounted on the mold base and having their meeting faces recessed to provide the side walls of a plurality of casting cavities, and a plurality of pilots in the mold base each forming the bottom wall of a casting cavity and each being adapted to maintain its original alignment with the mold halves regardless of the dilferences in temperature in the mold halves and base.

' l. A mold for making a plurality of cast ings simultaneously which comprises a mold base, mold members on the base and expansible lengthwise thereof, the meeting tacos of the mold members being recessed to form the side walls of a plurality 01E casting cavities, and pilots forming the bottom walls of the casting cavities and movable in the base by the said mold members as the latter expand lengthwise.

5. A permanent mold for simultaneously making a plurality of castings comprising a multipart mold base consisting of members spaced apart vertically and pilots movably retained between the said members, mold halves hingedly fixed to the mold base, and cooperating with the pilots and each other to form a plurality of casting cavities, the pilots being movable by the mold halves as the latter expand and contract under varyllli lltltl ing temperatures thereby maintaining the casting cavity walls in substantial alignment during the'casting operation.

6. A multipart permanent mold for simultaneously making a plurality of castings composed of a high melting point metal which comprises a mold base disposed out of direct contact with the molten metal, mold.

halves contacting directly with the molten metal and fixedat one end to the base and pilots in the mold base contacting directly with the molten metal and movable in the base by the mold halves and coincident with longitudinal expansion of the mold halves.

7 A permanent mold comprising a mold base consisting of members spaced vertically and a pilot movably retained between the members and projecting through and above one of the members, a hinge pin extending above the base at one end thereof, mold halves rotatably secured to the hinge pin to swing on the mold base, the mold halves being cut away to engage the sides of the pilot which project above the base and recessed thereabove to form the sidewalls of a casting cavity, the bottom walls of the cavity being formed by the said pilot.

8. A mold having a plurality of casting cavities comprising a mold base, two substantially non-warping hinged mold halves v fixed at one end thereof and adapted to be moved on the mold base, and pilots movable in and extending above the top of the mold 6, base, the top surface of each of the said pilots cooperating with adjacent surfaces of the said mold halves to form a casting cavity.

. 9. A multipart permanent mold for simultaneously making a plurality of castings 10 composed of a high melting point metal which comprises a mold base disposed out of

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