US1581790A

US1581790A - Casting and method of producing the same

Info

Publication number: US1581790A
Application number: US600656A
Authority: US
Inventors: Davis James Carey
Original assignee: Individual
Current assignee: Individual
Priority date: 1922-11-13
Filing date: 1922-11-13
Publication date: 1926-04-20
Anticipated expiration: 1943-04-20

Description

A fil 20, 1926. 1,581,790

J. c. DAVIS CASTING AND METHOD OF PRODUCING THE SAME Filed Nov. 15, 1922 2' Sheets-Sheet 1 A ril 20 1926., 1,581,790

'J. C. DAVIS CASTING AND METHOD OF PRODUCING THE SAME Filed Nov. 15 .1922 2 Sheets-Sheet 2 36 l 35 .I "I .29

55 I2 34 I0 9 "IE.

.In III] lgn E] 25 F4 1;l= v w m 25/30 $31 [nae/12%;"

, I 26 fig?? Patented Apr. 20, 1926.

UNITED STATES PATENT OFFICE.

. JAMES CAREY DAVIS, OF HINSDALE, ILLINOIS.

CASTING AND METHOD OF PRODUCING THE SAME.

Application filed Noveinberlti, 1922. Serial No. 600,65G.

1 of casting metal, and to improve means and methods for producing castings which are not only smooth and clean in that they are free from pits or holes and from entrained dirt-such as sand, but are notably dense as well as solid.

Pits, holes, dirt, and the like involve roughness, flaking. shelllng, and a consequent cutting action, since they 'cannot readily be machined out, and other obvious imperfections with an incident intolerably "great manufacturing cost due to the high scrap loss of the castings necessarily discarded on account of inavailability for the purposes contemplated.

It will be appreciated that castings of high quality, the attainment of which is one of my present objectives, are useful for many purposes, but are not only of utility but practically essential for a number of uses, such for'example as car-wheels and other structures more. or less analogous in certain characteristics.

The case of car-wheels is an example for which the invention is peculiarly adaptable, inasmuch as where desirable, additionally a hardening or other modifying element may be so introduced at such a place and stage and so regulated and determined, and with such degree of nicety as may be desired,

that not only a solidity but of metal throughout the casting, or certain parts thereof, may be secured but also that the repeated production of a run of castings of like composition and density may be attained.

The castings produced by my present improvements may be of uniform composition throughout, or the introduction of a modifying clement referred to may be effected when, if and as desired, thus in the furnace or cupola, in the ladle, or between the ladle,

and the mold, whereby the casting may be of differing composition in differentparts.

For the purpose of illustration of the present invention in its various aspects, I have therefore found it convenient in the present also homogeneity specification and drawings to refer to it in' connection with its adaptability for carwheels and the like, which may be of uniform or variable composition, according to the service in View.

In the production of such castings by other means and methods known to me I have heretofore experienced great difficulty not only in accurately apportioning the modifying element when desired butin attaining the requisite-solidity and density in the castings and in insuring a constant runof castings which are both of the composition, solidity and density sought for,but at the same time free from insuperable peripheral imperfections such as foreign matter,

shelling, irregularities of contour, -etc.,-

which are intrinsic and more than merely superficial and so involve actual rejection ofthe product.

The principal objects of my present invention therefore involve the provision of. an improved casting apparatus adapted for the inclusion of means for the production of castingsof quite. perfect solidity and great density; the provision of such an apparatus characterized by the'inclusion of means whereby such density may be intensified at predetermined localities; the provision of such an apparatus adapted for. the production of castings of varylng density, or varying both in density and com position; the provision of a casting apparatus characterized by the employment of an auxiliary source of molten metal for imparting solidity and high density to the casting; the provision of a casting apparatus including arotating mold for such purpose; the provision of an improved mold having means for receiving an ancillary source of molten metal, one wherein such ancillary source may be drawn upon to compensate for shrinkage in the casting as it cools or entrained gases are expelled from the casting or from the mold, and one adapted to facilitate the escape of gas from the mold cavity; the production of a casting char? acterized by predetermined variation in its density; the provision of such a casting fur-' predetermined varia-' which differs in kind as Well as degree from 7 those hitherto known.

The principal obj'ectsof my presentinvention furthercontempla-te the utilization of an improved method of making castings, which are of varying density in difi'erent portions, and, when if and as desired of difiering degrees of hardness in difi'erent portions, together with certain other objects which will be hereinafter disclosed.

In the attainment of the objects andadvantages above noted, in the avoidance of the objections and disadvantages mentioned, and in accomplishing certain ends and gaining certain benefits which will below be pointed out or clearly appear,'I have provided the constructions illustrated in the accompanying drawings which for purposes of convenience as before suggested are adapted for the production of a car-wheel such as one made of steel which is solid, dense, hard and resistant and consequently of excellent wearing qualities at the peripheral ortread portion, and may be relatively softer toward the center and thereforemore tough andless apt to fracture.

In these drawings, it will beobserved that m-- Figure 1 I have illustrated a mold provided with mean for rotating the same, and

a ladle for introducing molten metal into the mold, the mold being provided With ancillary means for supplying additional molten metal to the casting proper as it shrinks, the mold and casting being shownin central longitudinal section;

Figure 2 a plan view. of the mold of Figure 1;

Figure 3 a vi w of the casting therein produced;

Figure 4 an elevational view of a modified form of apparatus; and in .Figure 5 a paratus of Figure 4.

Referring first to the apparatus of Fig ures 1, 2 and 3, it will be noted that I may employ a mold, such as the car wheel mold '6, which is preferably mounted upon a support 7 which is rotatable by means of a suitable drivlng mechanism indicated gening 10 for directin into the mold molten metal from the lad e 11 or the like. 4 Interiorily the mold 6 is provided with an ancillary receptacle for molten metal,

the excess of which will not form part of the finished. casting. In the case of the production of such a casting as the car-wheel shown in Figure 3, I conveniently employ f two such receptacles which take the form of sinking

heads

12, 12 in the cope 1.3 of the mold 6. In the resultant castings such remainder of the redundant metal from the sinking heads 12, '12, indicated at 12, 12,

are of course duly removed, before they are put into use.

plan view of part of the ap Referring now to the apparatus of Figures 4 and 5, it-will be seenthat I here mount in a convenient place as in a it the desired number of molds 6, each of which is mounted on a rotatable table 7 driven by gearing 8.

For the purpose ofprovidin means whereby the molten metal from the ladle 11 may be maintained at a height substantially uniform and will thereby be caused to descend in a solid column of uniform which comprises a supporting bed 22 carried upon axles 24 the wheels of which 25 are revoluble thereupon and arranged to ride upon rails 26 the outer ends of which are mounted upon

trucks

27 and 28 which in turnride upon the rails 29 and 30' oppositely disposed about the molds 6.

In carrying out my improved process of making castings, the modifying element, such as manganese may be added in the fur-- nace or cupola, or in the ladle 11, or between the ladle 11 and the mold 6, but for the purpose of introducing and incorporating most perfectly and commingling and distributing most thoroughly the modifying-element into le moved from one flask.

the stream of flowing metal 31, which as will be seen on reference to Figure 4 preferably takes the form substantially of a column with parallel sides, I may make use of an apparatus which here comprises a vertical casing 32 for containing the modifying elements, such as manganese, a lateral extension thereof 33, a nozzle 34 the ejector of which, 35 is depressed somewhat fromthe horizontal, and a pipe 36 connected to a source of air or other fluid pressure supply, and inserted into the apparatus below the casing 32 to the end that the modifying element may be drawn therefrom by fluid pressure and forced into the flowing stream of metal; In practice, I have found that the best results are attained by the use of pressures between approximately 50 and 125 lbs. per'square inch which will cause the modifying element to penetrate the stream of molten metal, and that by flattening the ejector 35 so that the spray of modifying material may be spread out to approximately the diameter of the stream, and depressing the end of the ejector so thatthe modifying material will strike the flowing stream in the direc tion in which it flows, it will enter and be 'ously incorporated with the molten metal,

and will not have the tendency to become segregated in masses therein nor to be unevenly disposed therein, nor to remain on the surface of the stream and subject to the action of the air.

For certain purposes it is highly desirable to attain an accurate and uniform proportioning of the quantities of the modifying element and molten metal as they enter the mold. In order to do this, obviously it is not only desirable to have the modifying element delivered in uniform and unvarying quantity, but it is also desirable to have the molten metal delivered in uniform and -unvarying quantity. If the metal be taken .directly from a pouring ladle of the ordinary type its velocity will vary as the height of the metal in the ladle varies. From this it follows that if the rate. of flow of the modifying element be uniform, the proportion of the modifying element and metal delivered to the mold will vary, because the rate of flow of the metal is not uniform. In overcoming'this I have provided a choke device whereby I a m enabled to maintain the height of the metal in that device substantially uniform. As a result, the discharge of metal into the mold is uniform. Furthermore, as thehead of metal in the choke device is relatively small, the issuing stream is in the form of a substantially solid column. Furthermore, by emplo ing the injecting device referred to, the mo ifying element is immediately embedded in and firmly held by the flowing metal, and is therefore uniformly carried into the mold.

In the production of a wheel of uniform composition I preferably employ molten steel having a specification of 0.25 to 0.50% carbon and-1.25 to 2.0% manganese, which may be introduced in the furnace, though it Will be understood my present improvements are available for'the production of wheels having a yarying composition by graduating the addltion of the modifying material as canbe accomplished readily by introducing it between the ladle and the mold for example.

The molten metal is then poured into the.

mold 6 and as such mold fills the ancillar mold cavities are filled and the sinking

headz

12, 12 are formed.

The pouring'being finished, rotation of the mold is efiected until the casting is solidified, whenitis removed from the mold and the excrescenc-es 12312 are removed and the customary finishing operations are performed. i

From experience I have ascertained that if the mold 6 remains stationary I cannot infallibly attain the degree of solidity and density in the castings, desired by me, but that utilizing a rotating mold at say 25 to 100 R. P. M. centrifugal motion is imparted to the molten metal to such an extent that the metal filling the sinking heads 12.

,12 servesto completely fill the outermost parts of the 'mold 6 in such a manner that I am not only enabled to prevent the formation of holes and secure a solid and clean casting, but am enabled to attain in addition to highly complete solidity a marked degree of density.

Inasmuch as I preferably make use of" centrifugal force the extent to which the benefit thereof is attained obviously depends in part upon the'rate of revolution imparted to the mold 6 and in part. the time interval through which such movement is con tinued.

, It is believed that the operation of my present invention and various applications of its use will be understood by those skilled in the art without further detailed description.

For certain purposes and in certain of its phases it may be employed in connection v ing to the prospective uses of the castings produced. v y

In the claims Where I use the terms to preferentially densify, to preferentially compensate, to preferentially solidify, or to preferentially condense, I mean to include such property as would be obtained in rotary casting wherein an ancillary supply of molten metal is included as would favor the'addition of molten metal from the ancillary supply to the periphery of the casting rather than to the body of the casting.

Having thus described my invention and illustrated its use What I claim as new and desireto secure by Letters Patent is:

1. The method of casting car wheels which includes introducing molten metal into a mold and then rotating the mold after pouring so as to impart. centrifugal motion to the molten metalto force it outwardly to the confines of the mold to an extent sufficient to densify the metal of the periphery of the casting.

2. The method of making car wheel castings which includes pouring molten metal into a mold including an ancillary chamber closed to the atmosphere and introducing metal in said chamber to provide an ancillary supply of molten metal to preferentially compensate for rim shrinkage of the first mentioned metal as it cools.

3. The method of making car-wheel castings which includes incorporating through a main pouring gate molten metal into a mold also including an ancillary metal re- 1,

in said, means to. furnish an ancillary sup ply of metal and rotatingthe mold to'impart centrifugal motion .of the first mentioned molten metal and'thereby draw into the -mold a supply of the last mentioned cry of the casting.

ings which includes incorporating molten metal into a mold including an ancillar metal retaining means and introducing mo ten-"metal in said means to furnishan ancillary supply of metal and rotating the mold as to impart centrifugal motion to the first mentioned molten metal,- "and'thereby draw into the mold a supply of the lastmentioned m'oltenmetal to an extent sufficient to preferentially solidify *the metal of the periphery'ofthe casting; V 1

. 5. .The method of making castings which includes incorporating molten metal, into a mold including anancillary metal retaining means and introducing molten metal'in said means to furnish an. ancillary supply of metal and rotating'the mold to impart centrifugal motion-to the first mentionedmolten metal and thereby draw into the mold a supply of'the last mentioned molten metal to an extent sutli'cient to preferentially solidify the metal of the castin-gwith a, force characteristic of the centrifugal force of substantially rimvelocity.

6. The method-of making castings which includes incorporating molten metal into a mold including an anclllary metal. retame ling means and introducing molten metal in said means to furnish ancillary supply of metal and rotating the mold as toimpart centrifugal motion to the first mentioned molten .metal, and thereby draw into the mold a supply of the last mentioned molten metalto an extent-suflicient to preferentially condense and solidify the metal of the casting withfa force characteristic of the cen-;

trifugal force of substantiallyrim velocity. 7. The methodof making car-wheel castingswhich includes introducing molten metal into a mold and an ancillary metal retaining means 'to-provide Jan ancillary supply of molten metal,- and rotating the mold after it"is poured so as to impart'c'entrifugal 'motionto the first mentioned -molten'me'tal,

and thereby draw into the mold a supply of the last-mentioned molten metaL;

8.- The method of making castings which includes'pouring into a mold a mixture of fluid metal and amodifying element and r0 the mold after it is poured.

Wtatin .v

- 9.- The method of making car-wheel castings' which includes pouring'into a mold a mixture of fluid metal and a modifying ele- .ment and rotating the mold after it is poureda-ta .rate of speed sufficient to condensethe outer portions of the metal.

' 4:. The method of making carwheel cast ti i tvedr. I

10. The method'of maliing car-wheel castpouring into a mold a a eletially. the same direction asthe flow thereof 7 between the'ladle and the mold, and rotating the mold after it is oured.

ingsof varying composition and density which includes introducing into-a mold a stream of metal in the form of substantially.

11-. The method of ma ing car-wheel castsupply of metal, and-rotating the mold after the casting is poured to force metal into the mold from the ancillary supply.

12. In a. casting apparatus, in combination with a source of molten metal,a nd a mol d, and means for rotating the same, a .limited ancillary source of molten metal for preferentially compensating for shrinkage in the casting after the pour from said first mentioned source is completed and as the mold is rotated. 13. In a rotary casting apparatus, provided with a pouring gate, and ancillary means closed to atmosphere for receiving a mold molten metal, from the main body of metal for the formation of a casting} therein.

provided with a pouring gate, and an ancillary sinkinghead closed to atmosphere for receiving molten metal for the formation of a casting the-rein.

15. In a rotary casting apparatus, a car wheel mold provided with a pouring gate,

and internal ancillary means for receivingmolten metal for the formation of a cast- "ing therein disposed near the periphery ofg the wheel.

16. In arotary casting apparatus, a car wheel mold provided with a pouring ate,

and an interiorly disposed ancillary sin ing head closedto atmosphere for receiving molten, metal for the formation of a casting. therein disposed near the periphery of POlIltS as produced by substantially com 14, In a rotary casting apparatus, a mold letely pouring in a mold and then rotating' the same.

18. "As a new car wheel-casting of predetermined uniform progressive variation in density at difierent "points decreasing from the periphery. in-,

, wardly as produced by substantially comarticle of manufacture, a

pletely pouring in a mold and then rotating the same. 19. As a 'new article of manufacture, a

facture when the metal is fluid and the cast- 1 ing has been poured as produced in a rotary mold including an internal ancillary supply 1 of molten metal intermediate the axis and the periphery of the casting.

20. As a new article of manufacture, a car wheel casting containing 0.25 to 0.50% carbon and condensed during the course of manufacture when the metal is fluid and the casting has been poured as produced in a rotary mold including an internal ancillary supply of molten metal intermediate the axis and the peripheryof the casting.

21. As a new article of manufacture, a car wheel casting containing 1.25 to 2.0% manganese and condensed during the course of manufacture whenthe metal is fluid and the casting has been poured as rotary mold including an internal ancillary supply of molten metal intermediate the axis and the periphery of the casting.

22. As a new article of manufacture, a car wheel casting containing 0.25 to 0.50% carbon, and 1.25 to 2.0% manganese and peripherally condensed during the course of manufacture when the metal is fluid and the casting has been poured. as produced in a rotary mold including an internal ancillary supply of molten metal intermediate the axis and the periphery of the casting.

23. A new article of manufacture, a car wheel castingcontaining 0.25 to 0.50% carbon, and 1.25 to 2.0% manganese and condensed during the course of manufacture by rotation of the mold when the metal is fluid and the casting has been poured'as produced in a rotary mold including an internal ancillary suppy of molten metal intermediate the axis and the periphery of the'casting.

24. The method of making car wl1eelcastings which includes pouring into a'mold amixture of fluid metal and a modifying .ele-

ment, the modifying element being introduced between the ladle and the mold, in substantially the direction of the flow of the stream of molten metal, and rotating the mold after it is poured.

25. The method of making car wheel castings which includes pouring into a'mold a mixture of'fluid metal and a modifying ele-- ment, the modifying element being forced into the stream of -molten metal in substantially the same direction as the flow thereof:

between the ladle and the mold, and rotating the mold after it is poured.

26. The method of manufacturing a car wheel casting, which comprises introducing molten metal into a mold; including an internal ancillary means ofretaining the molten metal located near the periphery of. the casting and then rotating the mold for conproduced in a densing the molten metal at the outer portion of the casting.

ing, which comprises introducing molten metal together with a modifying substance into .a mold including an internal ancillary means for retaining molten metal located 27. The method of manufacturing a castnear the periphery of the casting and then rotating the mold for condensingthe moltenmetal at the outer portion of the castin 28. In a device of the character described, in combinatioma'source of molten metal, a mold and means for rotating same,-and an ancillary limited source-of molten metal located between the axis and the periphery of the casting intermediate the confines thereof.

29. In a casting apparatus, in combination with a source of molten metal, and'a moldand means for rotating the same,'a nd ancillary limited source of molten metal located between the axis and periphery of the casting intermediate the confines thereof for compensatingior shrinkage in the casting after the pour from said first mentioned source is completed.

30. The method of making castings which includes introducingmolten metal into a mold including an ancillary metal retaining means, rotating the casting to impart centrifugal force against the periphery of the casting and augmenting the supply of'meta'l in direction of the centrifugal motion with a force characteristic of the centrifugal force at points within the limits of the body of the rotating casting. c

31. The method of making car wheel castings which includes introducingmolten metal in a mold including an ancillary metalretainmg means, rotating the casting to impart centrifugal force against the periphery of" the casting and augmenting the supply of metal from the said ancillary means, intermediate the axis and periphery of the casting at substantially the tread momentum.

'32.- In the process of molding castings in a rotating mold, the step which includes introducing an. ancillary supply of molten metal near the (peripheral portion intermediate the axis an the body of the casting.

33. In the process of molding castings in 1 a rota-ting mold, the steps which comprise introdh'cing metal into the mold and forcing in an ancillary supply of metal under pressure at points intermediate the axis and the periphery of the body of the casting.

34. In the a rotating mold,'the steps which comprise process-ofmolding castings in introducing metal-into the mold and forcing in an'ancillary supply of metal under pressure substantially equal to that" induced by the peripheral casting.

' JAMES CAREY DAVIS.

momentum off-the rotating