US1776543A - Cooling system - Google Patents

Description

Sept- 23, 1930. F, G. CARRINGTON 1,776,543

COOLING SYSTEM Filed March 25. 1927 Snowdon f6'. CHRRINGTa/V ffl 4 Sheets-Sheet Sept. 23, 1930. Ff G. cARRlNGToN COOLING SYSTEM' Filed .March 25. 1927 4 Sheets-Sheet. 2

Sept. 23, 1930. F. G. cARRlNGToN COOLING SYSTEM Filed March 23.

).927 4 Skwets-Slwerl Syvum/Wo@ @H01 was,

Sept- 23, 1930. F. G. CARRINGTN 1,776,543

COOLING SYSTEM Filed March 23. .1.927 4 Sheets-Sheet.

. h V I 9 I 9 i Patented l Sept. 23, 1930 UNITED' STATES PATENT OFFICE FRANK G. CARRINGTON, OF ANNISTON, ALABAMA, ASSIGNOR TO FERRIC ENGINEER- I ING COMPANY, OF ANNISTON, ALABAMA, A CORPORATION OF DELAWARE COOLING SYSTEM I Application led March 23, 192'?.A Serial No. 177,652.

This invention relates to a cooling system, and more particularly to a cooling system in a centrifugal casting apparatus where it is desired to progressively cool themold.

While my invention may be employed in any of thevmethods -for casting by a centrifugal process, it is particularly adapted for use in the so-called endpouring trough process. In this process, metal is poured from the end of a trough. over which a rotating mold telescopes, whereby the molten metalis built up in spirally related columns on the interior of the mold.

Diiiiculty has been' experienced in effecting av proper cooling of the mold, and as a result the operative lives of the molds have been shortened, and there have been certain delehowever, the cooling has been commenced terious effects in the cast objects, principally brittleness, which has necessitated an annealing process for the casting. There have been various cooling systems devised to take care of this situation, most of which have consisted in surrounding the mold with a water jacket. Others' have provided pipes for sprinkling the mold with a cooling medium.

In all the systems heretofore employed,

along the length of the mold at the same moment. The metal, however, is poured from the end of a trough which moves axially with respect to the mold, so that there is an interval between the pouring at the two ends of the mold. Inasmuch as the cooling is commencedfat the same time, metal is poured on; successive portions .of the mold which have been cooled for different periods of time, and which portions therefore are of different temperatures. This means ,that

a casting is subjected to different cooling along its length, especially with reference to initial cooling upon coming into contact with the mold.

Inasmuch as the cooling eflect on the mold is transferred tothe poured metal,this variance in the cooling of the mold makes for a longitudinal differential in the cooling of the metalin other Words, the metal poured at the spigot end ofthe mold is cooled more `rapidly than at the bell end. As the texturel n etwa casting is a function of its cooling, 'the ployed have also necessitated a subsequent an-l nealing process. There have Vbeen nomeans adapted for a gradual coolirg of the mold,`

and necessarily of the molten metal, but, on the contrary, the cooling has been so sudden that the cast pipes have been case chilled. Annealing has been necessary to render such case chilled pipes usable.

The problem is, therefore, one of cooling lthe mold so that it is'capable of functioning over a series of castings, and at the same time preventing the too rapid cooling, and consequent case chilling, of the poured metal. To accomplish this is one .of the objects of this invention.

Another object of this invention is to devise a method of cooling a mold.

Still another object of thisl invention is to devise a method of progressively cooling a mold in a 4centrifugal casting apparatus.

Yet another object of this invention is to provide a cooling'system for a mold.

A further object of this invention is to provide a system-for cooling a rotary mold at a predetermined relationship to the deposition of molten metal within the mold.

A still further object is to provide a cooling system, whereby the mold in a centrifugal casting apparatus may be cooled progressively and at variant rates along its length.

Yet a further object of this invention is to provide a cooling system for a centrifugal casting mold whereby the mold is subjected to the cooling action only as metal is deposited therein. f N To accomplish the above, and other im- "i erating the individual cooling members so r that additional increments of the mold are Each group of pipes is independent of the eooled, or so that a section of the mold;` which progresses its length, is cooled.

To insure' a more accurate comprehension of my invention, but in no way limiting myself to the particularapparatus and details therein set forth, reference is made to the accompanying drawings, in` which similar numerals indicate corresponding parts.

Figure 1 is a top plan view of the complete invention;

' Fig. 2.is a side-elevational view of the apparatus with a portion of the mold cut away;

Fig. 3 is a cross sectional view yalong the line 3-3 of Fig. 1, looking in the direction of the arrows;

Fig. 4 is a cross sectional view of one of the sectional pipes along the line 4 4 of l Fig. 3, looking in the direction of the arrows;

Fig.` 5 is a detailed view of the truck arm shown in Figs. 1 and 2;

Fig. 6 is a top view of a ladle truck and valves by the operation of which a mold is cooled in a section which progresses longitudinally ofthe mold;

Fig. 7 isa detailed view of the valve partially in section, along the line 7-7 of Fig. 6;

Fig. 8 is a sectional view of the valve on the line 8-8 'of' Fig. 7; Y

Fig. 9 is a top elevational' view of a valve, being a modification of the valves shown in Fig. 6. wherebythecooling effected by a sec-'- tion is terminated by stages; I

Fig. 10 is an adaptation of the invention, in which molten metal is depositedbefore the cooling commences; Fig. 11 is another adaptationin which cooling of the mold precedes the deposition of metal.

Referring more particularly to Fig. 1, a casting mold l having a bell end 2' and a spigot end 3, is mounted upon trunnions 4 supported on roller boxes 5. The mold is rotated by mechanical means,not shown in the drawings,I the rotation generating the centrifugal force necessary to disperse the metal over theinterior surface of the mold.

lStandards are spaced along the length of the mold and mounted thereupon are blocks 7. Cooling sections comprising independent pipes'8 closed at'both ends, extend longitudi- -nally of the mold and are supported in thel blocks 7. These pipes have apertures to disperse acooling medium upon the mold.

groups in the other sections of the system, but the pipes of each group are connected to a supply pipe for that group by the feed pipes9. f

Valves 10 are mounted'inthe`system,'a`s indicated, to cutoH or regulate near the standards the supply of cooling medium into -any-desired sectio.' Adjustment of these valves enables a different cooling effect along the length of the pipe to he Lhtained. This v1s pf'co'isiderablevalue for tfis frequently lnecessary to increase the cooling ofl the bell end, because of the greater deposition of metal there, for instance. l

The medium isl conveyed to the dispersing pipes by the independent supply pipes 11 and 11 on which are mounted near their junction with a conduit 12 valves 13, 15, and 16.

These valves have levers 14 for opening or closing the passages. therefore may be operated and controlled by the valves 13. It will be observed that the valves are regularly spaced, except for the two first valves 15 and 16, which are in closer proximity, lthe reason therefor appearing hereinafter.

-An end pouring trough` 17, for conveying molten metal from a ladle 18 to that place in the mold where it is desired to deposit Any desired section the metal, is mounted on a truck 19, which linger rod that its end willhe capable oflcon= tact'with the levers 14 of the valves 13, 15

and 16, opening 'the valves when passing alon the track to the right. In order that this nger rod may be raised so that the truck may pass along the track 21 without coming finto contact with `the levers, a hinge 23 is provided so that the lower portion of the inl ger may belraised.

At the commencement of a pouring operation, the truck is placed at theend of the track adjacent the mold and during'the process is moved to the right by mechanical means, not

shown. During this passage the finger comes *I mto progressive contact with thelevers 14,

opening the valves and consequently bringing into playsuccessive sections of the cooling system. At the termination of the casting operation the entire series ofsections will be dispersing a cooling medium upon 'the Lexterioi` of the mold, and `when it is desired to remove the cast pipe thevalves 13, 15 and 16 may be closed manually, or bysuitable mechanical means.

In Fig. 2 there is a more detailed illustra-` the left until the spout or end 26 of the trough' is at approximately l27. The valve 15, admitting the fluid tothe leftmost section is opened l beforeor at the same time :the pouring is commenced. Inasmuch as a greater thickness is required at the bell end of the pipe than at the barrel of the pipe, the trough remains substantially stationary at 27 for a short time.-

When a sufiicientamount of metal has been deposited, the truck begins its movement to the' right, and in the process the finger rod opens the valve 16 when the spout of the l trough reaches 28. This causes the next sec- Fig. 2 also sets forth a base 29 on lwhich the mold an`d major portion of the cooling system is supported. It will be noted that the track 21 is on a somewhat lower plane,

although this is not necessary. The supply pipesI 11 and 11", conduit 12, and valves are below the track 21, which necessitates the angle formation of the finger rod 23.

In Fig. 3, a' cross sectional view of the mold and .cooling apparatus, the staggered alignment of the dispersing pipes 8 is'shown. This can be compensated-for, ho\vever,vby so arran in fthe a ertures in the pipethat thel g g P stream of the mediumis directed on themold at any desired place.v As -before stated, the ends of the pipes 8 are closed as-at 30. This figure also shows Vthe arcuate shape of the .'upply pipes 11, and the standards 6.

The apertures 31 in thepipes 8 are regularly spaced as shown in Fig. 4, although under certain conditions other arrangements may be made. The mounting of the pipes 8 in the blocks 7 is of such a nature as to preclude a loosening or slipping of the pipes `in respect to the mold, and the ends 30 of the pipes are set flush with the far side of the block 7.

The finger rod 22 is provided with a hinge 23, through which a bolt, or other suitable pivot "32, as shown in Fig. 5 ,`extends. This enables an operator to raise the lower portion 22 when returning the truck to the starting position. If the valve is incapable of movement counter-clockwise, and the hinge-is easily' operated, it4 is unnecessary to manually p raise the lower part of the rod 22', for upon coming into contact with the lever 14, the

lower part will swing upwardly The complete invention is designed to provide a method of progressively cooling a mold by extendingthe cooling area in stages as the metal is deposited therein, the progression being consistent with the deposition of the metal stream. While this is not a steady progression but one wherein increments are added, by shortening the sections the sectional effect will be so slight as to be negligible. But regardless of the length of the sections, all that portion of the mold is cooled which has upon its interior surface a hot mass of metal, and the cooling is not'eifected until practically the moment atwhich the metal is poured.

It will benoted that the commencement of the sprinkling Within an increment is simultancous throughout that increment, and in this respect the apparatus which is the subject of this invention, differs from the cooling system covered by my copending application Serial No. 172,355, filed March 3, 1927'. All the foregoing refers to a cooling system in which, at the moment pouring ceases, the

entire mold is being cooled. When the leftmost section is once put in operation it continues until the termination of the complete process, This means that the different sections are subjected to different periods of cooling, the bell end, for instance, being cooled for a longer period than the spigot, or plain, end. Usually this variation is imma- ,teriah for the cooling is of vital importance only when metal is within. the critical range of temperature. The resulting microstructure of the metal is dependent upon the speed at which the metal passes through this range.

Above and below the critical temperatures the metal .may be cooled rapidly or slowly without any appreciable eii'ect upon its structure.

The system heretofore described is designed to avoid asudden and rapid cooling of the metal within the critical range. As stated, however, there does remain a differential cooling between the spigot and bell ends of the`pipe.- 1t may therefore, under certain circumstances, be desirable to provide a cooling system, bythe operation of which each portion of the mold is subjected to the same7 amount of cooling as every other portion, articula rly with reference tothe length o time it is cooled. This is accomplished by providing a system in Which a sectional cooling is effected. The cooling section, of any desired length, progresses longitudinally of the mold. This means that, as the section progresses, any given point on the mold' is cooled for the same length of time as every other point, provided the number of cooling units in a progressive section remains constant, and that there is no acceleration in the speed at which the section travels.r

This progression, as in thc case of incre- .mental cooling heretofore described, accomplished by the apparatus shown 1n Figures 1 llt) neously throughout the length'v of each stage.

Il have shown in Figures 6 to11 inclusive an apparatus'for accomplishing this type of cooling. Certain modifications are embodied in the various types illustrated in the Iigures.

In Figure 6 there is shown the trough 17,

`the ladle 18, mounted on the truck 1 9, the

supply pipes 1l and 11 and the conduit 12, all as'shown in the precedingfig'ures.

The linger rod 22 is shown mounted on the truck, its exact position however being changed from that occupied 1n Figs. 1 and 2.

As will appear hereafter, the position of this arm is immaterial, provided it is in a proper spaced relationship to an arm which is shown in Figure (i. Both of these arms are provided with hinges 23 as heretofore described.

Secured to the pipes 11 and 34, which latter pipe is joined to the conduit 12, is a valve'. v

Referring to Figs. 7 and 8,*this valve comprises a casing which is Screw-threaded to the pipes 11 and 34, as at 36. Threaded upon this casing is a cap 37 having a-central aperture therein. A valve stem 38 passes through this aperture and is secured to the valve 39, shown in this drawing as of' the mushroom type. The valve rests within the valve seat 4l, and is held in fluid-tight contact therewith by means of' a helical spring 42, the upper portion of which presses against the cap 37. The valve is provided with a channel 43, of' the same size and shape as the channels 44 of the valve seat and 45 of the casing.

When in alignment with the two last mentioned channels the valve channel permits the passage .of Water from the pipe 34 to the lpipe 11. This valve may be rotated within the seat and its channel turned `as indicated by the dotted lines 46 in Fig. 8. When in this last position the valve aHords a waterf tight obstruction in the"` path of th channels 44 and 45 of the valve seatand casing. It will be observed that to insure this obstruction to the flow of water, it is necessary to rotate the valve 90.

Upon the upper portion of the valve stem 38' there is aiiixed Va spindle 47 secured to the stem by meansof a bolt 48, or other suitable yfasteningmeans, in order to prevent rotation of the spindle with respect to the stem. The

'spindle supports four lever arms 49, at right angles to each other. l

The finger vrods 22 and 33 in passing `the valves, turn the valve levers through an arc of 90. This in turn effects a rotation of the valve 39, and closes the flow of waterjf the valve is open. If, on the other hand, the valve is closed, the finger rod 22 opens the valve.

As the truck moves from left to right, and

'and 33,- and the speed at which the truck moves, determine the length of time any given cooling section is'in operation. Variations, therefore, in the distance of the two fingers may be made in or-der toaccomplish any desired result for a particular casting operation.

It will be noted that the Valves are closed rapidly and the cooling by any section terminated abruptly. It is sometimes desirable to stop the cooling gradually, and to accom-v plish this I have shown in Figure 9 a modification of the valve employed.

The valve casing, seat, and valve stem may be of same type as that shown in Figures 7 and 8. Instead of having only four levers, however, there are providedtwelve levers or spokes 5l, mounted upon the spindle 47.

The arm 22 is providedforl opening the valves, but there are three arms 52, instead of only one, for closing the valves. The arm 22 is of a length to contact with the spokes at a point on their radii, where a rotation of 90 may be effected. As above pointed out,-

this is a suflicient movement of rotation to cooling. The farther apart the arms 52 are spaced, the more gradual will be the termination of the cooling. It may be desirable under certain circumstances to employ only one arm 52, reducing the coolingeiect one third at some determined time and then allowing the cooling to continue thus diminished. For instance, after the temperature of the casting has dropped below/ the critical ranges, it may be desirable to decrease, yet

' not terminate altogether, the cooling of the mold. lAnother modification may embrace an apparatus in which the positions of the arms 22. and 52are transposed, so that the cooling is gradually commenced but suddenly terminated. Or again, a plurality of arms 52 may be employed to both gradually commence and graduallyterminate the cooling.

In Figure-2 there shown a synchronizalll) tion of the cooling and pouring in which the two operations are practically concomitant. This is usually the preferred method, but unf.,

mi. der certain circumstances it may be. desirable f to have the cooling precede, or, under other circumstances, to follow the pouring. While the cooling in Figure 2 isA incremental, it can readily be seen how this concomitant cooling might easily be effected in the case of a cooling by a progressive section. In Figure 10 I Vhave shown a portion of'a mold and cooling apparatus in-whic'h a rogressive section fol.- lows the pouring onf-.t e metal. In this'par'- ticular ure the cooling succeeds the pourstance of approximately one cool-' ing unit. This distance may be varied, either ing at a Y' increasing or diminishing the distance, and consequently the time, between the pouring and cooling. Under such an arrangement, the metal is poredin a mold of substantially atmospheric temperature, and after the metal is cooled for a certain period, independent of artificial cooling, the apparatus increases the rapidity ofthe cooling. This might be especially desirable-for instance,

-whee a metal is poured at aj temperature within,\'or just above, its critical range. In

this Way itwould pass through the range at ,a slowrate, and then the artificial cooling would cxpediteits reduction to a temperature at which'it might be removed from the mold.

As pointed `out hereinbefore, it lis of primeA importance that a metal pass through its critical range Aof temperature at a controlled speed, for the I cooling within that ran e de# termines certain properties-kof the finished casting simultaneously wit deposition of metal inthe mold.

o In Figure 11 the cooling precedes the deposition of metal.l Here again the precedence `isby one coolin unit, which as above stated,

may be vari with -diierent operations. When the cooling precedes the deposition of metal the mold. is considerably reduced in temperature by the time metal is poured in it. Under some 'circumstances this may be found desirable. It may be that wh'ere a metal is poured at a considerably higher temv perature than its critical range, this method would expedite the drop in temperature of the metal to the critical range, and. from th'ence onwardtthe metal cools unaided by arti cial means. y Y

the.- foregoing I` have shown certain modifications of 4my invention. -It Ais to be understood that the same general principles underlie all applications of my invention. .Tbhe relationsh1 of thecooling and the pouring applies wit equal force, whether it be. an incremental cooling or a cooling ina progressive section. Under certain conditions' of operation it may be extremely desirable to insure that when metal is poured that orti'on ofthe mold receiving the metal is 0 the same temperature a every other portion of the mold at the moment metal is poured, and

especiallythat every'particle of metal passes jthroughits critipal ran eat a` uniform speed,

regar less o f the positlon in the mold I:that

such'a particle is deposited. My apparatuses and processescan be so operatedl as to ac-- f complish-this andotherldesirable results.

M invention insures a slwerand more gradiial cooling than` is thecase with the .coo g systems heretofore em loyed.1 The cooliiig effect of the latter has been so acute l and rapid as to cause a case chillin of the cast pipe,1andinlorder to render suc a pipe usable, it is necessaryto subject it to an annealing process whereby the outer surface is lsoftened to an extent where it 'is 'possible to employ it in ordinary operations. The obviatIon of such a costly and time consmin step as 'annealin by this invention will facilitate the rapi and-more effective casting of metal pi e.

Where I ave used theiterm pipe in the specification and claims," it is to be understood as covering a casting of any descrip- .tion produced by the centrifu al process.

is also to be understood that t e wordfiron isnot to limit the use ofmy invention to the production of` ferrouscastings. M invengio tion may 'be employed to cast'artic es comf posed o any material.

While I have shown and described the preferred embodiment of my invention, I Wish it tobe understood that I do vnot confine myself tothe precise details of construction herein setv forth, by way of illustration, as it is apparent that many changes and variations may e made therein, by those skilled in the art, withoutY departing from the spirit of the invention, or exceeding the scope` of the appen ed claims.

I claim: l

1. A 'system for cooling-a mold in a cenltrifugal casting'prgcess comprising a series and means to successively operate the valves.

- 3.. A rotary casting'apparatus comprising a 'revolvable mold, supported longitudinally thereabove independent sections of a cooling system,- feed lines for -the sections having .valves therein, a pouring trough capable of longitudinal movement with respect to the mo1d,and means associated with the` oui-ing trough for'opening in succession .t e said valves. v r

- 4. A'frotary casting apparatus comprisin a rotatab mold, supported thereabove an extendin mold aV series of independent sections of paired pipes for discharging acooling fluid upon theexterior of the mold, an independent feed' linepwith valve niounted thereon, for each section, a trough extendin within the moldAY and adapted to be with rawn while molten netal is poured therefrom, a ladling device attached to the trough and capable of movement as the trough is withdrawn from the mold, and means on the ladling device for lopening theabove 'mentioned valves.' v

substantially the length lof the 5. A rotary mold Cooling system comprising. individual cooling sections, means for commencing and terminating the operation of the individual sections and other Ameans -synchronized with the deposition of metal in the mold for actuating the {irst mentioned means. y

6. A centrifugal casting apparatus comprising a rotatable mold*` a trough adapted to move-axially with respect to the mold, a sectional cooling system, individual valves for admitting a -eooling medium to the sections,

and means coacting with the trough for openinfr and closing the valves. Y

A, centrifugal casting -apparatus comprising a mold mounted for rotation, a ladling device, the mold and ladling device relatively movable with respect to each other, a plurality of independent pipes mounted adjacent lthe mold and adapted to disperse a cooling iuid thereon, means for regulating the admissionof a cooling fluid to the several pipes, and means'carried by the ladle for actua-ting the last mentioned means ina definite relationv to the deposition of metalwithin the mold.

In testimony whereof I alix my signature.

FRANK G. CARRINGTON.

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