US1224906A - Method or art of casting fluid metals. - Google Patents

Description

H. H. DOEHLER.- I METHOD 0R ART OF CASTING FLUID METALS APPLICATION FILED SEPT. I0, 19]!)- 1,224,906 Patented Ma s, 1917.

I .My" 'nvention HERMAN H. D'OEHLER, OF BROOKLYN, NEw"Yo3K,'- AssIeNoa T0 mama DIE casrme comranm; A- coaronar on ornnw YORK.

MnrHoD on lam-gramm :E'LUIn ME'rALs.

"To azzwaamama omm-1 "j 4 Be it known that I, HE MA HQDonHLER, I

a have invented, .certa'in new-,and useful Improvements in the.Method or Art'of Casting Fluid llletals, of which the following is a specification, reference being had therein to;

the accompanying'drawingswhich form part'thereofffl. i P

relates to the method or art I of casting lfiuid metals, and. more. particu- ,larly toaiiiethodor art. wherein the metal is fOrcedand compacted, within a mold by means of fluid :pressureJ In United States Letters- Patent No."

973,483 granted to me"underf-dat e of Oct. .25,f 1 910, I have ,described a; .meth od or art particularly adapted for use iii c'asting metaving ahighfusing point. The method t, 'andthe apparatus described in my resaid Letters Patent-,fhave been extenboth of high fusing, and; low fusing alloys. In making castings ofhigh fusing alloys, I have found it impiacticable to make a large number; of castings from a single metal mold,; or die, because ofthe 'diiiiculties of introducing the molten, metal to the apparatusin'. proper condition to" secure a -uni- 1 form ,of- 'commerciallyl perfect castings. When 'themetal is melted in a,furnaoe,i ndependent of the apparatus, and is delivered to the apparatus by means ofaladIe, thereis a tendency of themetal to lose sufficient heat through radiation to make it too sluggishto flow freely when entering the mold. To. avoid this condition, it was necessary to either,. maintain the mold at a sufficiently high temperature to compensate for the loss ofjheat by the molten metal; to raise the temperature of the molten metal above its fusing point a degree which would prevent the loss ofsullicient heat to interfere with-the flowofthe metal into all parts of the mold or die; or"to .u se -bo.th these expedientsf Inasmuch as' this :rnethod or art is used for; producinglcastings, having a finished surface, and aficurate as to dimenslons, 1t 13 notion yessential that the metal Shall flow used in making commercial castings V I notchill 'sorapi'dly when in the" mold' or'die, as to cause surface imperfections or concealed blow holes, but that it Patented Ma a, laid.

.hpplicatiohilledSeptember10,1915. Seria1:No.i49 ,8 7 4E v 1 shall, after entering the mold or die, remain in condition for-a sufiicient interval to enable it to be compacted or compressed by the air or other fluid pressure applied to it as it is flowing under grayity-into and after it has entered the mold or die.

When the temperature of the mold was raised-' as, above described, I found that I couldguse a high fusing alloy and produce commercially perfect-castings, but that the high temperature to which the mold or die was subjected not only had a tendency to rapidly warp the mold or die and prevent accuracyin-fthe dimensions ofthe castings subsequently made therein, but'to limit the number of castings which could be produced g The heating of themetal materially above its. fusing point, had the disadvantage that it was not only injurious to the metal, but

did not admit of uniformity in the product. Furthermore, when usingthe metal, at very high temperatures,- there was a tendencytoward the warpingof parts of small-dimensions within the mold/or die.

When both raising the moldor die to a high temperature, and raising the tempera ture of the metal well above its fusing point, I found both of the disadvantages above referred to were present. l

The conditionsabove referred 0 have not been present when practising the method or art, and using the apparatus of my aforesaid Letters Patent with whiteanetal alloys,

such having a lower fusing point than alloys rich in copper, or yellow alloys. 1

By means of the herein describedimprove 'ments in the method omart described in my aforesaid Letters Patent,,I am enabled to makecastingsof high fusing alloys particu larly those rich in copper, under conditions which avoidthe maintenance of an BXQQS:

.sivelyhigh temperature of the moldforf'die, 3

or the raising of the'ftemperature 'fofthe metal to be'castmateriallyfahove its fusing point, thus permitting prolonged use of the mold or die'and avoiding possible deterioration of the metal-: I have made castings by thisl method or art of a copper alloy-having va.z-fusing point of about two thousand degrees Fahrenheit with a mold or die used ordinarily for, and maintained under the same conditions og'dlnanly used in, castlng white metal alloys having a much lower fusing point; and these castings have been accurate as to measurements, have had "a smooth, flawless surface, and havebeen free from superficial or concealed blow holes.

In the invention herein described, the manner of charging the mold or die is sub stantially the same as described in my aforesaid Letters Patent, this invention relating more particularly to the specific manner of preparing each charge-of metal, and of delivering'it to the die or mold in such condition and in such volume as is necessary to produce oneormore castings of the desired bulk together with that excess necessary to form a sprue.

My present invention has all the advantages of my patented invention when \casting high fusing alloys with the additional advantages thatthe mold 'or die is not re- 'quired' to be maintained at a temperature sufiiciently high to warp the mold or die or make its handling in ejecting the casting slow; and that the alloy may be cast while at substantially itsfusing point.

The Invention consists primarily in a method or art of casting fluid, metals con- I slstmg of sub ecting a meltmg pot or am cible containing metal of substantially the bulk of the casting to be made to a temperature approximating that of the fusing point of the metal, pouring the molten metal in said melting pot or crucible from within an inclosed chamber into a metal mold, and thereafter forcing and compressing the metal by following it up with anelastic fluid under high pressure, and in such other novel steps and practice as are hereinafter set forth and described and more particularly pointed out pended.

Referring to the drawings: Figural is a vertical section through an apparatus in which my methodor art may be practised;

Fig. 2'is a section on the line 2-2 of Fig. l;

Fig. 3 is a perspective view of a convenin the claims hereto aptional casting to be made;

shown in Fig. 3,

Fig. 4 is a perspective view of an ingot. of substantially the bulk. of the casting and the sprue formed in making the casting, and

Fig. 5 is a vertical section of the melting pot to be used with the ingot'therein preparatory to its being'melted. r

Like letters refer to like parts throughout the several views.

In the practice of my improved method equilibrium while there is a barrier of molor art, a metal alloy having a high fusing point is brought to and maintained at the desired or necessary temperatnre in a melting pot a. The alloy is illustratedinfthe accompanying drawings as being lIIf ,l3l1G form of an ingot b when placed in the meltmold or die, with the ing pot, although it is apparent that this is not essentialto the invention. The quantity of metalconditioned in the pot a is of substantially the"same bulk as that of the casting 'orcastings to be'made therefrom,

and thesprue formed-in making the castmetal'and placed within an inclosed cham- --ber 0 from which itis poured into the mold.

or die d while stillata temperature of substantially that of the fusing point of the alloy. Leading from the chamber 0 to the mold d is an ingate opening e-which is constricted adjacent the mold-and extended adjacent the chamber 0 to form a sub-chamber 0 at the bottom thereof. tends substantially vertically so as to cause the molten metal to have a tendency to flow under gravity from the chamber 0 into the mold.

The chamber 0 isadapted to'be opened to permit the insertion of the melting pot a therein, 'and'the mold or die (1 is made in a plurality of parts to permit the drawing or ejection of the casting. The melting pot a is provided with a'suitable handle a by which it may be handled and operated.-

The chamber 0 having been closed after This ingate 6X- the mounting of the melting pot a therein,

the melting pot is overturned and the molten metalcontained therein is poured into the bottom of the chamber '0 and the sub-chamber-c from whence it will be in to how under gravity througlrthe ingate 6 into the mold. The constricted passage between the chamber 0 and the mold or die d formed by the said sub-chamber and the said ingate' will collect and concentrate the molten metal.

' librium of pressures in the chamber 0 and mold or die-a3 when pouring the metal from the melting pot a, and that the admission of fluid pressure to the chamber 0, destroys this ten metal. between said chamber and the preponderating pressurewithin the chamber 0.

This'condition accelerates the rate of flow ofthe molten-metal, "converting the entire 7 metal to an extent to prevent the desiredcharge into a metallic ram as itenters the mold and forcing it into all parts thereof, filling all cavities and interstices instantaneously. Incidentally, as the metal enters the mold or die, it is compressed or compacted 1n a manner to avoid any concealed blow holes,'the fluid under pressure bemgexcludcd from the mold or die by the metal passing through the ingate. v

The metal sets or solidifies substantially simultaneously with itscontact 'with the walls of the mold, retaining sufficient fluidity, however, toward the center and top of the casting to admit of the compressionor compaction above referred to.

While there is a tendency of the metal to chill and adhere to the wall of the ingate c, this does not interfere with the flow of the rapid charging of the metal into the mold or die. It does, however, form .a substantial sprue, and must be taken into account in determining the bulk 'of metal to be conditioned in the melting pot a.

The chamber a is vented before the mold or die is opened to permit the drawing of the casting.

When,referring to the f conditioning of the metal, herein, I have reference merely to'the bringing of-the metal to, or its maintenance at, av temperature of, or slightly aboveathe fusing point thereof whilein the melting pot fromwhich it ispoured.

While-I-havejmade satisfactory castingsin -an ordinary steel die, such as is used for making castings of lower fusing alloys than those to. be cast by the method or art herein described, it is apparent thatt'his invention is'entire'ly independent of the material or construction of the die and the particular pparatus by means of which it is'p'rac tis'ed.v Theessential and dominating characteristics of the invention herein described, as compared with my aforesaid patented method or art, are that a charge approxi-j, mating in bulk, the mass of metal required for asingle casting, is 'brou ht to the desired: ileina melting or necessary temperature vv pot, and that the chargeis poured directly from said meltingpot, as a ladle, into the mold or die under the conditions herein specified. These characteristics, I have found,

prevent a loss of suflici'ent heat to "prevent the metal flowing freely from the pressure chamber into-the mold; and perm t the casting of a metal having a high fusing point,

while at a temperature substantially that of the said fusing point and without'raising the is placed in the melting pot is immaterial so long as the bulkof such metal is sufficient only for a single casting operation, and so long as the melting pot and the metal therein are subjected to a temperature of substantially the fusing point of the alloy used just prior to such casting operation.

While I have referred to an alloy having a fusing point of about two thousand-degrees Fahrenheit, my method or art may be practised in making castings of an alloy the fusing point of which may be above or below this temperature.

Having described the invention, What I claim as new and desireito have Letters Patent, is

1. The herein described method or art of casting fluid metal, consisting'of subjecting a melting pot or crucible containing metal of substantially the bulk of the casting to be practised by made to a temperature approximating that of the fusing point of the metal until the metal is reduced to a molten condition,

I pouring the molten metal in said melting pot vor crucible from within an inclosed chamber into a metal mold, and thereafter forcing and compressing the. metal by fol lowing it up with an elastic flujd under high pressure.

2. The herein described method or art of casting fluid metal, consisting of subjecting a melting pot or crucible containing metal of substantially the bulk of the casting to be made to a temperature approximating that of the fusing point of the metal until the metal is reduced-to 'a molten condition, pouring the molten metal in said melting pot or crucible from within an inclosei chamber into a metal mold, and subjecting it while it is flowingfrom said chamber -to the mold.

to an elastic fluid under high pressure.

3. The herein described method or art of casting fluid metal, consisting of subjecting a melting pot or cruicible containing metal of substantially the bulk of the casting to be made to a temperature approximating that of thefusing point of the metal until the metal is reduced to a molten condition, pouring the molten metal in said melting pot or crucible from within an inclosed chamberlinto a constricted passageway lead ing to a metal mold, and forcing and compressing the metal by subjecting it while it is flowing through said passage way to an elastic fluid under high pressure.

a 4. The herein described 'fmethod or artof casting fluid metal, consisting of subjecting a melting pot or crucible containing metal of substantially'fthe bulk of the casting to be made to a temperature approximating thatof the fusing point of the metal until the metal is reduced to a molten condition, .pourmg themolten metal in said meltlng pot or crucible from withln an inclosed chamber into a metal mold, mamtaining an i equilibrium of pressures within said chamher and said-mold while pouring, and destroying the equilibrium of pressures with a predominating pressure within said inclosed chamber whereby while the metal is flowing to'the mold by gravity its movement is ac- 'celerated 'and it is forced into and compressed in the mold imder heavy pressure.

5. The herein described method or art of, casting fluid metal conslstlng of sub ecting a melting pot or crucible containing metal of substantially the bulk of the casting to be made to a temperature approximating that of the fusing point of the metal until the metal is reduced to a molten condition, pouring'the molten metal in said melting pot or crucible from within an inclosed chamber into a constricted passage way leading to a metal mold, maintainingan equilibrium of pressures within said chamber and said mold while pouring, and destroyingthe,equilibrium of pressures with a preponderating pressure within said inclosed chamber, whereby while the metal is flowing to the mold by gravity its movement is accelerated and it is forced into and compressed in the mold under heavy pressure.

6. The herein described method or art of casting fluid metal consisting of subjecting a melting pot or crucible containing metal of substantially the bulk of the casting to" be made to a temperature approximating that of the fusing point of the metal until the metal is reduced to a molten condition, pouring the molten metal in said melting .pot or crucible from within an inclosed the metal is reduced to a molten condition,

pouring the molten metal in said melting pot or crucible from Within an inclosed chamber into a constricted passage Way leading to a metal mold, and forcing and compressing the metal by subj eating it while it is flowing through said constricted pas- I sage way to the expansion of an elastic fluid under high pressure.

8. The herein described method or art of casting fluid metal. consisting of subjecting a melting pot or crucible containing metal of substantially the bulk of the casting to be made to a temperature approximating that of the fusing point of the metal until !the metal is reduced to a molten condition,

pouring the molten metal in said melting pot or crucible from within an inclosed chamber into a metal mold. maintaining an equilibrium of pressures within said chamber and said mold while pouring, and destroying the equ1l1br1umof pressures with a preponderating pressure within sa1d 1nis accelerated and it is forced into and compressed in the mold under heavy pressure by the expansion of an elastic fluid under high pressure. I i

9. The herein described method or art of casting fluid metal consisting of subjecting a melting pot or crucible containing metal of substantially the bulk of the casting to be made to a temperature approximating that of the fusing point of" the metal until the metal is reduced to. a molten condition pouring the molten metal insaid melting pot or crucible from w1thm an inclosed chamber into a constricted passage way leading to a metal mold, maintaining an equilibrium of pressures Within saidchamber sa1d JH-SSEIO'G wa' and-sa1d mold while l b n o r I pouring, and destroying theequlhbrium of pressures with a preponderating pressure within said inclosed chamber by'the expansion of an elastic fluid under high pressure, whereby while the metal is flowing by gravity its movement is accelerated and it is forced into and compressed in the mold under heavy pressure. 10. The herein described method or art of the bulk of the casting to that of the fusing point of the metal until the metal is reduced to a molten condition, pouring the molten metal .in-said melting pot, or crucible from within an inclosed chamber into a 'mold maintained at a temperature below the fusing point of said metal, through a constricted passage way, having an enlarged portion at said chamber,

and delivering a'fluid under'high pressure to said inclosed chamber immediately after pouring said metalfrom said melting pot or crucible whereby while the metal is flowing by gravity, its movement is accelerated and it. is forced into and compressed in the mold under heavy pressure. r

In witness whereof I. havehereunto af fixed'my signature in the presence of two subscribing Witnesses, this 1st day of September, 1915. p

HERMAN H. DOEHLER.

Witnesses:

, F. T. WnNTwoR'rir, A. S. HUNKELE.

7() closed chamber, whereby while the metal is flowing to the mold by gravity its movement casting fluid metal consisting of subjecting, a melting pot-or crucible containing metal .of substantiall 'be made to at temperature approximating

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