US1329295A - Rotary casting - Google Patents

Description

D. s. DE LAVAUD. ROTARY CASTING. AFPUCATION FILED, MAR. 3|19|9. 1,329,295. Patented Jan. 27, 1920.

VQ Q` N\ 0N NN AJT lill? 4 NN 0N \N om ATTORNEYy i To all whom t may concern.'

' of metal DMITRI SENSAUD DE LAVAUD, OF NEW YORK, N. Y.

ROTARY CASTING.

Specification of Letters Patent.

Patented Jan. 27, 1920.

4'Application led March 3, 1919. Serial No. 280,452.

Be it known that I, DIMITRI SENSAD DE LAVAUD, a citizen ofthe United States of Brazil, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Rotary Casting, of which the' following is a specification.

This invention relates to the art of utiliz-l ing a rotary mold for the casting of hollow metallic articles, preferably partly centrifugally; the invention being particularly applicable t'o the casting of annular articles of -considerable length as compared with their diameter.

As it well known, rotary casting machines as heretofore constructed' have comprised broadly a rotary mold and a trough, spout,

runner or gate for feeding the molten metal into the interior ofthe rotating mold. In some cases, as is desirable for casting elongated annular articles, the mold and trough or spout have been relatively movable axially of the mold; but in all such cases, as far as I am aware, when the feeding means-was a trough, the relative movement between mold and trough has been primarily forl completely overlapping the trough by the mold before spilling the metal from the trough into the mold and where the feeding means has been a spout, the spout has been so designed at its continuously. open dischar end that the metal has either been discharged into the mold in spirally laid subdivisions in a curve of flow reaching the mold at a slight' angle in the vertical plane containin the axis ofthe mold, or the iow shaped like the fraction of an annulus so that the metal reaches the mold at a very slight angle to the axis of the mold and on both sides of the axis ofthe mold. By the statement that the iow of. metal contacts the mold is ofcourse meant that the flow of metal directly contacts the mold, as at the beginning of thel laying in the mold of the irallyl related subdivisions of metal, or

s that the iow of metal practically reaches .the mold on merging wlthithe previously laid spiral subdivisions of the molten metal. Neither of these previous systems is practical for the making of commercial articles,

say pipe, because neither case satisfies a discovery which I have made as to the ideal conditions under which the molten metal should be laid in the mold, which is to say as been substantially annular or that the molten metal should be delivered downwardly and at one side lonly of the .of thel inside of the mold; preferably, the metal being delivered at such speed and at such inclination lof stream-flow relative to the inner periphery of the mold and its di rection of rotation, 4that the force- .of the streamas it impinges a inst the mold is great enough to insure t at practically all the metal at any instant being delivered to the mold is flung against the mold and travels under its ow-n momentum with the molds inner periphery at least until the combined effect of centrifugal force and intermolecular friction within said metal functions to maintain said metal `fixed relative to previously deposited metal. The explanation of this is, I now believe, that 4if the molten metal is not delivered in this manner a churning or concrete-mixer effect is set up, and, moreover, globules of molten metal. .are thrown out `and up in the mold and partially congeal while in the air and so result in a multiplicityv of more or less uni-` fact that friction between the molecules of the molten iron delivered and between the y iron and the inside of the mold isa factor in at least cooperating with centrifugali the mold. Consequently, wherever it -is stated inthe appended claims that the metal 1s dlscharged at substantially the velocity force to spread the metal uniformly around of the mold, the meaning is that the metalj is delivered as above described.

It will be seen from what follows that the present invention, While it .may be advantageously used for the 'casting of an annular article of any outside diameter as compared withits wall thickness, and an annular article of any metal, as cast iron, is

particularly valuable for the casting of annular articles of comparatively small outslde diameter and yetof considerable wall thickness, since it is obvious that the use of a l the casting,

trough, which type of feeding means gives so much better results in a moldV on a horizontal or substantiall A horizontal axis that the old s out type of eeding means has been practica ly abandoned, may not be used -at all if it is of sullciently small outside diameter to clear the predetermined bore of the annular' article-and at the same time of suflicient capacity to deliver Without appreciable pause the amount of molten metal required to provide the large Wall thickness.

The present invention involves a new process and a novel apparatus which may advantageously be used in carrying out such process, whereby the above discoveries ma be taken advantage of and the herein ind1- `cated advantages be realized.

The process, brieiy, may be described as the casting o f an annular metallic article in a rotary mold on a substantially horizontal axis, which consists .in laying the metal in the mold in successively deposited spirally related subdivisions while guidin the flow of the metal adjacent to the mold to cause the. metal to flow in a limited sheet to one sidev of the mold axis. By the term substantially horizontal axis is meant also an axis which is inclined suitably from the horizontal but never'beingnearer the vertical than the horizontal, whereby if desired another feature of the invention may be taken advantage of, which is the ossibility of tilting the mold axis from the liorizontal before casting to affect the velocity of the flow of metal 1n the limited sheet mentioned. Preferably the sheet is so vguided as to approach the mold in a path nearer a plane perpendicular to the axis'of the mold than a vertical `plane containing such axis. Preferably, also2 the metal flowing from the feeding means into the mold ,is so guided that the metal flows into the mold only at one side thereof. Preferably, further, the metal before thus approaching the mold, is guided over a distance substantially axially of the mold, by which is meant that it is ided lengthwise of the mold whereby the eeding means( may be conveniently ar- 50 ranged, in an apparatus wherein the mold and trough are relatively movable during to facilitate forming the annular article by progressively laid spirally related subdivisions of the molten metal. Preferably, also, the metal delivered to the mold hasthe same velocity, orv else as'near the same veloclty asl practical conditions will admit, as the peripheral velocity of the inside of the mold, by which is meant the average perlpheral velocity ofthe inside of the mold where themold is rovided with depressions and elevations to orm an annular article having an exterior conformation speclally shaped; but in any case best results are obtained when the metal is de .the mold and the livered to the mold. pursuant to thev principles of velocity and direction of stream-How hereinbefore disclosed. In other words, broadly the referred process involves directing the s eet of metal to continuously approach the mold at one side ofthe mold axis only, at a certain minimum speed and at a special inclination.

The preferred apparatus by which thls process may advantageously be carried out mvolves broadly the combmation of arotary mold, a metal distributer of the spout type adapted to project inside the mold and constructed and arranged vfor continuous] discharging molten metal inside the mol operatin means for moving the distributer and mol relatively lengthwise of the mold, movable feeding means, as a tilting reservoir for deliverlng molten metal to the distributer adapted to be moved or tilted to vary the rate of delivery of molten metal to the distributer, and means controlled b the relative movement of either the distri uter distributer angularly bent `to one side only' of the mold and terminating in an o nspout mouth adapted to direct the mo ten metal discharged `from the distributer in a.

stream substantially tangentially striking the mold. Preferably the feeding means is a pivotally mounted tiltable molten metal reservoir provided with a pouring edge coincident with such pivotal axis and having a calculated interior confirmation so related tothe location of the pouring edge that in moving the reservoir angularly about its tilt-pivot from one position to another molten metal is delivered to the distributer in fixed relation to the rate of discharge of molten metal from the distributer to the mold. The apparatus also preferably'includes means for angularly tllting the distributer slightly from the horizontal to increase or decrease the velocity of thedischarge of moltenmetal from the discharge end of the distributer, to correct as 'much as possible any difference between .the velocity at lwhich the molten metal reaches ripheral/velocity of the inside of the m d. Preferably also the operative connection between the mold and the reservoir for controlling the feeding of metal 'from'the reservoir to the distributer menced between the mold and'distributer.

Preferably the ap aratus also includes a plate or the like, 'rectly vconnected to the operating meansV for synchronizin -relative movement between mold and distri uter and tilting movement of the reservoir and directly pivoted on said pivot axis and in turn having the reservoir pivotallymounted thereon, whereby tilting of thel plate tilts the reservoir, and also includes a part on the plate and a co-actin part on the reservoir for acting as an in ex to signal when the` reservoir is filled with molten metal to the predetermined maximum, irrespective of the presence of previously 'congealed molten metal in the reservoir.

The inventionwill be more clearly understood from the following description, when taken in connection with the accompanying drawing, showing the preferred apparatus,

which may be used to facilitate carrying out the process of the present invention.

In this drawing, Figure 1 is a vertical axial sectional view of the entire apparatus, partially in section;

Fig. 2 is an enlarged detail view showing in vside elevation and on enlarged scale the parts at the right hand end of Fig. 1, including the right hand end of the distributer, parts of the means which operative?7 kconnect tilt plate and reservoir to the sli ing mold, such tilt plate and reservoir and the index; l

Fig. 3 is a transverse vertical section taken on line 3 3 of Fig. 2;

Fig. 4 is a' fragmentary view, being a transverse vertical section taken on line 4'-4 of Fig. 2;

Fig. 5 is an end elevation of the distributer at its spout end, the, arrow indicating `the direction of rotation of the mold;

Fi 6 is a top plan View at the end of the distributer shown in Fig. 5;

Fig. 7 is a side elevation of such end of the distributer, viewed as said end is viewed in- Fig. 1; and

v Fig. 8 is an enlarged detail view showing the part of the operative connection between the reservoir and the sliding mold for aii'ord` ing the initial lost motion described.

A rotary mold 9 is suitably mounted for as rapid rotation asdesired, on ball bearin or the like (not shown) properly supporte the mold being sleeved by a jacket construction 10 and carrying beyond such jacket construction a gear 11 or the like by which the moldmay be power driven. The jacket ma serve for water-cooling the mold from en to end. At its left end the mold has inserted therein an annulus 12, which may act, if used, as a carrier for an annular shelf for preventing the loss of molten metal bee yond the ends of the mold, for holding in placca core for forming a bell end on the article cast, for forming a convenient extractionmeans forthe article after being castor for any other purpose well known in the art. The'ja'cket construction 10, in which the `mold is suitably mounted to restrain the latter against relative movement lengthwise of the jacket construction, is in any familiar way supported on a base member 13 to permit sliding -the mold lengthwise on the base member.

A distributer 14 is provided, this disltribut'er constituting an open-topped gutter 85 carrying a canal 15 running lengthwise of the distr'buter, and of the mold, which latter is arrangedcoaxial with, or on an axis parallel to, the axis of the distributer. Near its right hand end the distributer is secured in a supporting standard 16 mounted on base member 13 and open at its top, as indicated .most clearly in Fig. 3, over the part of the canal passing through the support.

The left hand end of the distributer is' 95 formed as a separate piece 17, which may advantageously be made of hard molded carbon. Thisl piece 17 has a canal therein,

constituting the discharge spout of the dis- "tributer, shaped as shown in Figs. 5, 6 and 100 7, and which may be most briefly described as lying substantially coincident with approximately a. one-quarter turn of a' helixl of considerable pitch. It will be understood that when molten metal is delivered 105 through the canal `15 of the. distributer 14 to the spout of the piece 17, the metal will be discharged from the spout into the rotating m'old 9 at one side only of the axis of the mold and so as to approach the inside of 11o the mold substantially tangentially.

A means for feeding metal continuously to the end of the distributer partially surrounded by the standard 16, to cause a continuous outflow of such .metal from the 115 -spout into the mold, includes a tilt plate 18 pivotally mounted above the distributer transversely of the apparatus as indicated at 19 on a cross web 20 offset from one-end of the standard-16; a reservoir 21having l120 substantially the form of a 90 segment of a cylinder, and pivot-ally mounted on the tilt plate 18 by means of a gudgeon arrangement indicated at 22 in Flgs. 2 and 4, and

having a central limited pouring channel and edge 23 below the top of the tilt plate 18, the tilt plate being cut away at 24 in registry with such pouring edge; and a worm gear 25 keyed on the pivot shaft to the tilt plate and a worm 26 fixed on a 130 -and consequently the reservoir, (the latter moving toward the dot-and-'dash line position shown at 21 in Fig. 2, on rotation of the shaft 27,) will always and from beginning to end of each casting operation exactly compensate for the amount of metal at that instant being discharged from the spout of the distributer, the pouring edge 23 of the reservoir is so calculated and located, thereservoir is of such cross section in all planes including the axis of tilt, and the speed of sliding of the mold is so related to these factors as to attain the desired predetermination. In the first place, the end walls of the reservoir are parallel and perpendicular to the axis f tilt, the side wall of the reservoir below such axisis plane and the onl other wall of the reservoir is curved accor ing to a true circle on a radius terminating at the axis of tilt and as long as said plane wall. As a result, in'any degree of tilt of the reservoir 21 during movement from the position shown to that indicated at 21 in' Fig. 2, the liquid'level of the molten metal in the reservoirisof a constant' area. In

the second place, the rate of continuous operative connectionsinclude, in addition to the worm gear 25, the Worm 26 an'd the vertical shaft 27, a bevel gear 28 fast on the lower end of shaft 27, a bevel gear'29 meshing with the bevel gear 28 and fast on a horizontal shaft 30, a bevel gear 31 fast onl the other end of shaft-30, a bevel gear 32 meshing with the bevel gear 31 .and adapted to be rotated witha transverse shaft 33, and

a ,spur gear (notshown) fast on the shaft 33 and .meshingwith a rack 34 fast 'on the underside 'of the jacket construction 10 which carries mold 9. -A

In order to afford a slight lost motion at the commencement of a casting o eration, to allow the distributor preliminarl y to act to permit the metal thereby delivered to the distributer to commence discharging into the mold at the instant of commencement of sliding movement of the mold, means are provided for alfordingjthis lost motion in such way that the reserviik21 1s slightly tilted to fill the canal 15 in the distributor from end to end and to cause an overflow into the spout at the instant when the mold commences to slide to the left of Fig. 1. This means is provided by keymg, as shown -to the predetermined maximum, means are most clearly in Fig. 8, the bevel gear 32 to the `transverse shaft 33 in such a way thatv a key 35 on shaft 33 `has a lcertain amount of playin a circular recess 36 cut in the hub of gear 32. As a result, on starting to drive the operating means at the commencement of a casting operation, the shaft 30l and consequently the plvot axis 19 will performa slight rotation before shaftv 33 commences torotate; shaft 33 thereafter, however,ro'

' tating continuously with shaft 30.

In order to provide a means for predetermining precisely, just beforena casting operation, the instant When reservoir 21 is filled provided, in coaction withthe mounting of the reservoir on tilt plate 18 by means of the gudgeon 22, including a part 37 fixed on the vtilt plate and a co-acting part 38 ixed on the reservoir and forming the scale or 35 plunger arm of a spring scale 39 carrying a fixed suitably calibrated dial'40 over which an index 41 is movedI by the plunger 38 to indicate theweight of metal at any instant in the reservoir. By this means it is a simple matter to predeterminethe exact contents of the reservoir ,by Weight; and even W'here the refractory lining of the reservoir has adhering thereto particles or masses of prematurely congealed metal, as may be the Acase after several casting operations, the

Weight'of such adhering metal may be allowed for by using the springscale mechanism according to the well known principles of calculating tares.

In order to affect therate of flow of metal from the spout of the distributer, as an .auxiliary tosuch rate as affected solely by the speed of tilt and dimensions of the reservoir 21, means are provided for inclining the entire apparatus relative to thev horizontal and to maintain the .apparatus in such inclination duringa castlng operation. Such means includes a'center 'pivotal support 42 and end jacks 43 asshown in Fig. 1.

, I claim:

-1. The process of casting an annular metallic' article in a rotary mold on a substantially horizontal axis which consists in .laying themetal 4in the -mold in successively ,115

- deposited spirally related subdivisions while guiding the How of the metal adjacent to the mold to cause the metal to llow in a limited sheet sidewisely of the mold axis.

2. The process of casting an annular metal'lic article in a rotary mold on a substantially horizontal axis which consistsin laying the metal in the mold insuccessively deposited spirally related subdivisions while guiding' the llowof the metal adjacent to the 125 mold to cause the metal .to flow into the mold only at one side thereof at an angle to-the mold axis with such angle in a plane substantially transverse to the mold axis.

3. The process of casting an annular metallic article' in a rotary mold on a substantially horizontal axis which consists in laying the metal in the mold in successivelydeposited spirallyV related subdivisions while guiding the flow. of the metal adjacent to the mold to 'cause the metal to flow to approach the mold substantially tangentially at one side of the mold axis only.

4. The process defined in claim 1, wherein also the `How of metal is subjected to pressure sufficient to cause the limited sheet to reach the mold at substantially the same velocity as the peripheral velocity oi'l the inside of the mold.

5. The process of casting an annular metallic article in a rotary mold on a substantially horizontal axis which consists in laying the .metal in the mold .inA successively fdeposited spirally related subdivisions whilel '-:guidingthe iiow of the metal first substan- -ft-ially axially of the mold and then angu- '--.-.l'arly diverting the flow of the metal to disi.. harge the same as a substantially "solid lf'stream to one side of the mold.

2.5. 6. The process of casting an annular metallic article in a rotary mold on a substantially horizontal axis which consists in laying themetal in the mold in successively deposited Aspi-rally -related subdivisions while guiding the flow of the metal adjacent to' the moldtd-cause the metal to fiov'v against the mold at substantially the same velocity as tlle peripheral velocity of the inside of the mo discharging molten metal inside the mold,

operating means for moving the distributer and mold. relatively lengthwise to the mold, movable feeding means for delivering molten Ametal to the distributor adapted to be moved to control the rate-of delivery of molten metal to the distributer,\ and Ameans controlled by the relative movement of either distributer or mold and operatively connected to the feeding means for moving the latter constantly to supply moltenmetal vfrom the feeding means to the distributer in definite relation to the rate of discharge of molten metal bythe distributer into the mold.

9. The casting machine defined in claim 8., wherein the last mentioned`means-incl11des a driving element and a complementary driven element arranged to permit initial lost motion between said elements to defer relative movement between the mold and distributer for a predetermined interval of time to permit metal to be delivered from 7 The processdefined in claim 5, whereinl the feeding means to the distributer and to be discharged from the distributer' into the mold approximately at the instant when said relative movement commences.

10.. The casting machine defined in claim 8, wherein the distributer is an elongated member provided with a 'lengthwise canal, wherein the feeding means is arranged to deliver molten metal to the canal adjacent to .one end of the. latter, 'and wherein the '75 canal at the opposite end of the distributer is angularly bent to one side only of vthe axis of the mold and terminates in an open spout ada ted to direct the molten metal discharge from the distributer in .a stream so substantially tangentially striking the mold.

11.- The casting machine defined in claim 10, wherein the bent part of the canal is substantially -shaped transversely ofthe mold axis'. y 85 12. The casting machine defined in claim 11, wherein the bent part of the canalis -shaped in top plan.

13. The casting machine defi-nedA in claim' substantially coincident with approximately a one-quarter turn of a helix.

14. The casting machine defined in claim 8, whereinthe feeding means has a pivotally mounted -tiltable molten metal reservoir provided with a'pourin edge andhaving a calculated interior conl ormation so related that in moving the reservoir angularly about its tilt pivot from one position to an. other molten metal is delivered to the distributer in fixed relation to the rate of discharge of molten metal from the distributer by wa of the spout. l

15. 'he casting machine defined in claim i' 14,wherein the pouring ed e ofthe reservoir in each tilted position tereof is coincident with 'the ivot axis of the reservoir.

16. The casting machine defined in claim 15, wherein the reservoir when filled to a predetermined maximum holds itscontained molten metal below said edge and the interior of the reservoir is so shaped that in all tilted positions of the reservoir the molten metal level at any instant opposite the pouring edge is ofthe same-area as the level `thereof at any other instant irrespective of the de ee of tilt of the reservoir. 17. he casting machine defined in claim 16, wherein the reservoir is provided, as its total com lement of metal-holding walls, with a su stantiallv plane side wall below the pourin edge when the reservoir is filled to the pre etermined maximum. with a .circularly curved side wall, the radius of which terminates at all times at a center coincident 125 with the pivotal axis of the reservoir, and

with opposite end walls.

18. The casting machine. defined in claim 17, wherein a lift late is provided andl directly pivoted on t e tilt axis of the reser- 13o voir and directly actuated by said means controlled by said relative movement between mold and distributer, and wherein the reservoir is attached to the lift plate. v

19. The casting machine defined in claim 18, wherein in certain of its parts said lift plate is prolonged be ond the pouring edgeof the reservolr an beyond said pivotal axis to' limit' the upiow of molten metal from the reservoirandthe outflow thereof over said edge.l

20. The lcasting machine defined in claim 14,' wherein means are provided including a pivotal mounting between the reservoir and llift plate and a part on 'the plate and a coacting part on the reservoir, for acting as an index to signal when the reservolr is filled with molten metal to a redetermined maximuml irrespective of t e presence of previously congealed molten metal in the reservoir.

21. The casting machine defined in claim 19,wherein,one of the parts of the last mentioned means includes a 'spring-held scalemember, a calibrated scale, and an index moving member.

22. The casting machine defined in claim over the scale controlled by said 1', wherein means are provided for angularly tilting the mold and distribtuer slightly 4from the horizontal to increase or decrease the velocity of discharge of the 4 molten metal from the spout end of the distributer.

l 23. The casting machine defined in claim 8, wherein the operating means between the movable one of the mold and distri-buter and the feeding means includes a means for alording a lost' motion at the 4commencement of a castin operation, to allow the feeding means re iminarily to act to permit the metal there y delivered to the distributer to commence discharging into the mold at the instant of commencement of relative movement between mold and distributor.

24. In a rotary casting machine, the combination of a rotary mold, a metal distributer adapted to project inside the mold and constructed and arranged for continuously discharging molten metal inside the mold, op' erating means for moving the distribu-ter' and mold relatively lengthwise of the mold, movablefeeding means for 'delivering mo1-. ten metal to the distributer adapted to be moved to control the rateof delivery of molten metal to the distributer, and operat-l 26. The casting machine defined in claim l 24, wherein thel feeding means includes a tiltable lmolten metal reservoir provided with a pouring edge and having a calculated `interior conformation so designed that in tilting the reservoir from one position to another molten metal is delivered to the d1stributer in fixed relation tothe rate of discharge of ter. q

27. The casting machine defined in claim molten metal from the distribu- 26, wherein the interior of the reservoir is So shaped that'in all the various tilted .positions,v thereof the molten metal level is of the same area. l y

In testimony whereof I aiiix my signature.

DIHITRI SENSAUD DE LAVAUD.

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