US1573089A - Mold construction for centrifugal casting machines - Google Patents

Description

Feb. 1e 1926.`

^ J. RICE MOLD CONSTRUCTION FOR CENTRIFUGAL CASTING MACHINES Y Filedv Jan. l0, 1924 3 Sheets-Sheet 1 Feb. 16 1926.

J. RICE MOLD CONSTRUCTION FOR CENTRIFUGAL CASTING MACHINES Filed Jan. 1o, 1924 s 4sheets-Sweet 2 llmnnvlill lll, llrlx 314401114101, :fh-n. Rica Feb. 16 1926. 1,573,089

J. RICE MOLD GONSTRUCTION FOR CENTRIFUGAL CASTING MACHINES Filed Jan. 10, 1924 3 Sheets-Sheet 5 Patented Feb. 16, 1 9265.

uNiTED sTATEs JOHN RICE, OF BURLINGTON, NEW JERSEY.

HOLD CONSTRUCTION FOR CENTBIFUGAL'CASTING MACHINES.

Application tiled January 10, 1924. Serial'No. 685,443.

To all whom t may concern.'

Be it known that I, JoHN RICE, a citizen of the United States, residing at Burlington,

in the count of Burlingtonv and State of;

5 New Jersey, avefinvented certain new'and useful Im rovements in a' Mold Construction for entrifugal Casting Machines, of which the following is a specification.

This invention relates to' improvements in machines for centrifugally casting articles, such as pipes v The primary object of this invention is the provision cfa durable and practical type of mold which ma be economically prolt' duced, and which will permit of the casting vof relatively great numbers of pipes or other articles at low cost.

One piece molds of alloy steel forging are at present used in centrifugal casting machines, and these molds are utilized for casting of from one thousand to fourteen hundred pipes. These molds are made relatively thick in 4order to keep the .proper -ali nment thereof during rotation. These nio ds are rotatably supported at their ends only, because of certain practical disadvantages which prevent their support by rollers all along their lengths. For this reason the shell of the mold is of considerable thickness, so that it will not sag intermediate its ends and cast crooked pipes. `The outside of the mold is cooled, by a suitable cooling medium, while the inside of the mold is subjected to intense heat from the molten metal being cast therein, The heat, because of the thickness of the mold cannot be dis sipated through the thickness of the same, and consequentl the mold internally expands andbuck es. Whenthe hot pipe is 'pulled from' the mold the latter rapidly cools and contracts to its normal shape. This buckling and contracting of the interior of the mold in time produces numeroussmall cracks about the interior circumference of 4,5 the mold. When this takes place it is iinpossible to further cast pipe in the Amold without reboring the same. Of course, reboring the mold makes the internal diameter v greater, and there isa limit to the number of times the mold can be rebored. To offset the great expense necessary to cast pipes solely with the ordinary mold, it has been proposed to use a liner in the mold. The ineris ordinarily shrunk, screwed, or otherwise fixed in the mold, and it is well known Ito those skilled in the art to which this invention relates that such liners produce very unsatisfactory results. After casting from ten to thirty pi es in the lined molds it is impossible to wit draw the cast pipes. This is due to the fact that the practically imperceptible crack between the outside surface of the liner and the inside surface of the mold rovides an insulator which prevents dissipation of the heat throu h the liner, so that the liner is forced to uckle internally and contract about the part which itis supposed to cast. For this reason liners have not heretofore been generally used, and it is the ractice to use a homogeneous forged nio d. In myI present invention I use a'fliner'for molds which gives practical results, and which can be used lfor casting several times more pi es without the necessity of replacing the iner, than can be cast with present molds. I claim this result chiey because of novel means which I provide for expansibly supporting the liner relative to the mold, and providing cooling means between the liner and mold.

A. further object of this invention is the provision of centrifugal pipe casting apparatus which contemplates the provision of an easily replaced liner for molds.

A further object of this invention is the provision of centrifugal ipe casting apparatus which will materia ly lower the cost of casting pipes, and increase the outputof pipes to considerable extent over apparatusmnow' in use.

Other objects and advantages of this invention will be apparent during the course of the following detailed description.

In the accompanying drawings, forming a part of this specification, and'wherein similar reference characters designate corresponding parts throughout the several views,

Figure l is a longitudinal sectional view taken through the improved centrifugal pipe casting machine.

' Fig. 2 is a transverse cross sectional view taken through the machine illustrated in Figure 1. v

Fig. 3 is a fragmentary side elevation of a novel type of member used for yieldably supporting a liner within its mold.

Fig. 4 is a longitudinal sectional view taken through centrifugal pipe casting ap aratus constructed after the principle of t is CTI Cil

invention, with certain minor alterations over the form illustrated in Figure 1.

Fig. 5 is a cross sectorial view taken substantially on the line 5-5 of Figure 4.

Fig. 6 is an end elevation of the centrifugal pipe casting machine illustrated in Figure 4, taken from the bell end thereof.`

Figs. 7,8 and 9 are views of a .novel type of yieldable member for supporting a liner or portion thereof within its mold.

Fig. 1() is-a. cross sectional view taken through a further type of yieldable member for supporting a liner in a mold.

Fig. 11 is. an end elevation of the improved pipe casting machine, taken from the spigot end thereof.

Fig. 12 is a fragmentary cross sectional View taken through the outlet end of the pipe casting machine, showing a modified and novel type of bell liner which may be used Within its mold.

In the d'rawngs, wherein for the purpose of illustration are shown preferred and modified forms of this invention, the letter A may generally designate the improved centrifugal pipe casting machne, which may include a preferred type of mold construction B consisting of the outer mold C; liner D for the mold C; vand means E for yieldably supporting the liner D in the mold C. The improved lmold construction B is rotatably mounted within the casing F.

Referring to the improved mold structure B, the outer mold C thereof is preferably a casting or a forging which does not necessarily have to be machined, as is the case with present used molds. This mold C includes the elongated cylindrical shaped body portion 15 having integrally connected therewith the bell end 16 upon which the attaching flange 17 is outwardly formed. At its spigot end the mold C has the attaching fiange 17a formed annularly thereabout at right angles to the axis of the mold, and provided with the annular supporting flange 18 concentrically formed eXteri-orly of the mold body 15. The liner D is a one piece construction, and is assembled in the bore of the mold C from the bell end thereof. This liner D is considerably less in thickness than the thickness of the mold C, and is only of such thickness that the pipe may be cast accurately therein, so that heat may be dis-v sipated rapidly therethrough to prevent internal buckling. The liner D is-thus different from the conventional mold. It includes the cylindrical shaped body portion, 25 which is interiorly machined to provide the bore 26 over which the molten metal flows during the centrifugal casting process. This liner D at its forward end has the bell head 27 cast integral with the body 25, and provide-s the outwardlyA extending annular atf taching fiange 28 adapted for abutment against the forward surface of the mold liange 17 for attachment thereto, as by bolts 30.

Referring to the means for assembling the liner D in expansible relation within its parallel disposed inner and spiral shaped e supporting flange 38; the flanges 37 and 38A being connected by a web 39 which is U or V-shaped in cross section and transversely provided with perforations 40.

The liner D is assembled within the mold C with the spiral shaped member 35 disposed intermediate the liner D and its mold C, to provide the space or compartment 42 annularly about the liner between the same and the mold C, and through which space a cooling medium flows, as will be subsequently mentioned. This member 35 yieldably supports the liner D within the mold C normally in a concentric relation with respect tothe mold C, so that because of heating vof the liner D incident to a pipe casting operation, the same may expand without the buckling and cracking which takes place with the ordinary mold.

The liner D at its rear end is provided with an annular attaching flange 45, which is adapted to' detachably support a ring shaped attaching member 46, as by being screw threaded thereon. The attaching ring 46 is to be connected A,exteriorly to the rear surface of the mold 15', as by screws 47.

At its forward end the liner and the mold of the construction B are assembled, as

above mentioned, by means of the bolts 30. These bolts 30 are assembled first through the flan e 17 of the mold C so that their screw treaded Shanks extend outwardly from the outside surface of the liner flange 28, to detachably receive nuts 48 thereon. Compression spring Washers 49 are dis osed intermediate the nuts 48 and the liner an'ge 28, so that the liner D is resiliently held longitudinally within the mold C, and may have a linear expansion, as can well be understood. The openings 50 which are pro- Yvided in the liner fiange 28 for receiving the bolts 30 are relativel of greater dimension than the shank o the bolt, so that the liner bell 27 may have a radial expansion.

At its ipe withdrawing end the liner D is resillently or yieldably supported in its mold C by means of a ring shaped member 52 which is disposed in the space betweenthe liner and its mold at the Juncture of the fianges 17 and 28, substantially as is illustrated in .Figure l of the drawings.

This type of ring shaped Jmember 52 isrthe 'which may have perforations 55 therein through which the cooling medium may flow. In this form of resilient oryieldable member 52 the bight portion 54 may i be considered the' equivalent of the web 39 above mentioned for the spiral member 35.

The casing construction F of the centrifugal pipe casting machine A may be conventional 1n character, and is preferably cylindrical, providing the compartment therein with1n which the mold structureB is rotatably mounted upon rollers 61 which are carried by suitable radially .extending brackets 62, so that the mold C and its liner D are concentrically arranged within the casing compartment 60. At lits spigot end the supporting flange 18 of the mold C bears upon suitable annular supporting rings 65, which are located in thev spigot end of the machine, with packing material to prevent seepage of the cooling medium. The nozzle ring 68 is connected over the spigot end of the machine, `including a flange 69 which is screwed into the attaching flange 17 of the mold C, and which provides a tapered opening 70 converging toward the bore of the liner D.

At the bell end of the machine suitable bearing rings 71 are provided, mounted in the casing F, and supporting ythe mold construction in a water tight connection therewith. A pulley ring 72 is bolted, keyed, or otherwise fixedly secured about the bell end 16 of the mold C, adapted to receive a belt thereon or suitable driving element, by means of which the mold C and its liner D will be rotated in the casing F. A bronze ring 75 is preferably attached to the inner side of the mold flange 17, engaging the casing ring 71 to take up the end thrust of the mold. I

The cooling medium enters the compartment 60 of the casing F thru an inlet pipe 77, preferably adjacent the bell end ofthe mold, and outlets through a conduit 79 at the lower part and spigot end of themachine. The cooling lnedium is entirely disposed within the casing compartment 60 and aboutV the mold C. The mold C is sov constructed that this cooling medium will flow or be forced into the space 42'between the mold C and its liner D. To this end, tangential ducts 79 have been formed in the mold C, preferably having a slope slightly toward the bell end Of the mold, and catch cupsf) tiall `are disposed over the'- inlet ends-of the ducts 79 for the purpose of catching the cooling medium therein as the mold rotates for purpose'of directing the same into the tangendisposedducts 79. The positioning of t e ducts 79. so that they slope slightly toward the bell end of the machine impels the liquid longitudinall through the compartment 42 between the mold C and its liner D. Preferably at the bell endof the mold construction, outlet ducts are provided, as shown at 82 in Figure 1 of the drawings, and it can readily be understood that th cooling medium may flow long g'itudinallyl through the space 42, through the ducts 40 of the splral member 35, and through the ports 55 of the-ring shaped yieldable memer 52. As is illustrated in Figure2 of the drawings the casing' F may be movably support-ed upon tracks 85, in accordance with 4' conventional construction.

Referring to Figure 4, 5 and 6 vof the drawings, wherein is illustrated a modified form of the mold construction, the same includes a mold G with a novel type of sectional liner H. The mold G includes the relatively thick cylindrical body 90, which at the spigot endof the mold construction is provided with an annular attaching flange 91 having formed thereon the ring shaped bearing flange 92 concentrically arranged 'vwith the mold body 90. The bell portion 93 of the mold rGr is provided at the opposite end, which has an attaching flange 94 there on. The liner H is relatively thinvin coinparison to the mold G, for the reasons which have been above enumerated in connection with the preferred form of moldconstruction, the relation of the thickness of the mold G with respect to the liner H being even more accentuated than that illustrated in the drawings. The liner H includes the cylindrical shaped body portion 97, which at the spigot end of the mold construction is provided with the annular attaching flange 98. At its opposite end the body portion 95 providesa marginally reduced annular eX- tension 99 about which an annular extension 100 of the bell section 101 of the liner H is adapted to fit for purposes of centering the body portion 97 and bell section 101, substantially aslis illustrated in Figure 4 of the drawings. lThe bell section 101 at the pipe withdrawing end thereof is provided with the connecting lugs 102. In connection with the support of the body portion 97 inthe mold bore 105, the liner body portion 97 is inserted from the spigot end of the l mold G, and is concentrically supported in bore'lO `by means of ring shaped yieldable membersr 106. These members 106, which have been illustrated in cross section in concentric relation. The web 109. is substantially V-shaped in cross section, so that the bands 107 and 108 may moverelative to each other. The web 109 is provided with a plurality of minute perforations 110 to permit the passage of cooling medium along the space between the liner and interior surface of the mold G, as can readily be understood from the above description. The resilient members G are assembled about the liner body 97, and are attached thereto by screws 111 which are inserted thrqugh suitable apertures 112-provided in the inner band 107. The outer band 108 may be provided with suitable slots or enlarged openings 118 to permit the insertion of the screws 111 into the position illustrated in Figure 4 of the drawings. Of course it is understood that the inner band 107 is clamped against the outer surface of the liner body 97, while the outer band 108 snugly engages the inner circumference of the-mold G. A

' ring shaped member 52, which is of the design above described Ais preferably provided for supporting the spigot end of the liner body 97 adjacent the rear end of the mold G, substantially as is illustrated in Figure' 4 of the drawings, and suitable screws 114 connect the attaching tiange 98 to the mold G. The liner bell 101 is yieldably supported in position by means of the yieldable member 52 at its forward and rear ends within the mold G. Suitable bolts or like securing elements 116 are provided for connecting the flange 94 and lugs 102 of the mold and liner respectively, an'd to permit linear expansion of the liner resilient spiral spring washers 117 are clamped on each bolt between its -nut 118 and the outer surface of the liner lug 102. It is also preferred that the slots or openings 119 in the liner lugs 102, thru which the bolts 116 extend be of sufiicient dimension to permit the radial expansion of the liner section 101. Suitable tangential ducts 120 are formed in the mold G, referably sloping toward the bell endo the mold construction, and having cups 121 cooperating thereover for the purpose of directing the cooling medium into the space between the mold and liner, substantially in accordance with this feature above described for the preferred form of mold construction. The cooling medium exits from the space between the mold and liner at the bell end of the mold wherein suitable ports 125 are provided for such purpose. This mold construction is also provided with a spigot attaching member 127, and the, mold is ro-v tatably supported in any approved manner within the centrifugal casting machine casing. It is of course understood that the liner bell section 101 is inserted from the pipe withdrawing end of the apparatus, and this bell section of the liner may be used for su porting suitable indicia to be cast-n t e pipe, substantially after the manner set forth in my co-pendingapplication Serial Number 070,331, filed October 23, 1923.

Referring to the mold construction which is illustrated in Figure 12 of the drawings, the same merely shows a novel construction for expansibly supporting the bell section 130 of a liner within a suitable mold K. The mold K, of course, includes a body portion 135 of .cylindrical formation, which may or may not support therein a body liner as illustrated for the above described forms of invention. The mold K also provides a bell end 1,36 which is provided with. the interior screw threads 137 tapered with a diminishing diameter from the open end of the bell; the bell 136 also providing an attaching fiange 139. The bell shaped section 130 of the liner is provided with external screw threads 140 by means of which the liner may be threaded into the socket provided by the bell portion 136 of the mold. The mold at the bottom of the socket provided for the liner section 130 is provided with a reduced annular fiange 141 about which the shallow annular flange 142 at the forward end of the liner 130 fits to properly center the liner 130. At the bottom of the socket provided for the liner one of the yieldable members 52 is placed, so that it will permit relative expansion of the liner section 130 and mold. The liner section 130 is also provided with an outerconnecting flange 145 which .overlies the outer surface of the mold flange 139 and is provided with an annular extension 146 which fits within a suitable annular groove 147 provided inwardly of the forward face of the mold K. This groove 147 is greater in dimension than the thickness of the annular projection 146, so that radial expansion of the liner 130 is permitted. The screw threads of the liner section 130 engage in the screw threads of the bell end of the mold in a novel relation, providing spaces 150 at the tops and bottoms of the threads of the liner and mold, which are in communication with each other by means of suitable ducts 152 provided in the threads 137 of the mold at one side of the threads of the liner 130, and spaces 154 provided between the threads of the liner and mold at the opposite side of the liner threads, substantially as is illustrated in Figure 12. 'lhis permits the cooling medium to flow readily about the liner from onor end of the liner to the other for purpose of dissipating the heat incident to a casting operation. One of the yieldablc members 52 is clamped between the mold and liner at the outer end of the liner, adjacent the medium outlet ports 155. It is preferred that tangential ports 157 be provided in the mold K, communicating with the space between the liner and the mold adjacent the inner end of the liner section 130; Suitable 65, elongated one-piece liner having a relatively rapidly dissipated.

' the buckling and contracting incidentto the ordinary mold, primarily because of the fact that the heat from the molten metal is :Various changes 1n the, shape, size, and

arrangement of parts may be made' to thel forms of the invention herein shown and described, without departing from the spirit of the invention or the scope of the claims.'

I claim:

' 1. An apparatus for centrifugally casting pipes comprising a mold, a liner, and means for assembling the liner rwithin the mold to permit of uniform diametrical and linea/ expansion of the same throughout its length with respect to the mold.

2. Apparatus. for centrifugally casting pipes comprising a mold, a` liner for the mold, and yieldable means supporting the liner throughout its lengt-h in the mold in diametrical expansible relation therewith.

3. Apparatus for centrifu ally casting pipes comprising a mold, a iner for the mold, and means resiliently supporting the liner throughout its length within the mold in diametrical expansible relation therein.

4. Apparatus for centrifugally casting articles comprising a'mold, a circumferentially integral liner, and means yieldably supporting the liner throughout its length and intermediate its ends in spaced relation within the mold. x

5. Apparatus for centrifugally casting articles comprising va mold, a circumferentially integral liner, and a yieldable supporting member' between the inner wall of' the mold and the liner supporting the liner in expansible relation in the mold.

6. Apparatus for centrifugally casting articles comprising a mold, a liner, and a spiral shaped member yieldably supporting the liner within the mold. y

7 Apparatus for centrifugally casting articles comprising a mold, a liner. a substantially spiral shaped member yieldably supporting the liner in spaced relation within the mold, and means to permit the flow of a cooling medium between the mold and its liner.

8. Apparatus for centrifugally casting articles comprising an elongated mold, an

proper are much less expensive,4

thin wall in lcomparison'to the mold to permit of the diametrical expansion of the liner incident to temperature variations, and means yieldably su portin thevliner lon tudinally within t e molt? in spaced re ation therewith;

'aiv

i9. As an article of manufacture a sub I s'tantiall annular shaped transversely yieldble mol liner supporting member having transverse' perforations therein.

10.` As an article of manufacture a mold liner supporting member comprising innerand outer supporting portions connected byA a yieldable perforate web.

11. As an article ofmanufacture a spiral shaped mold liner supporting member comprising inner and outer band portions connected by a yieldable perforate web.

12. As an article of manufacture a mold i liner supporting member consisting of inner and outer supporting bands connected by a substantially U-shaped supporting webhaving perforations therein.y

13. A centrifugalY casting machine comi prising a stationary casing, a mold rotatably supported Within the stationary casing, means for directing a cooling medium against the outer surfacel of the mold within the casing, a liner, means expansibly supporting the liner within the mold, and means fixed' on the liner for ldirecting the cooling medium from the casting to the interlor of the mold between the mold and the liner for purposes 4o cooling the liner 14. Centrifugal vcasting apparatus comprising la stationary casing, a mold rotatably supported within the casing, a liner, means connecting the liner within the mold for rotation therewith and in expansible relation therewith, and means for directing cooling medium into the casing about .the mold and from the casing Ainto the mold about the liner.

15. A centrifugal casting machine comprising a mold,'a liner, means supporting the liner in spaced relation inthe mold., said mold having transverse ducts therein for conveying a cooling medium from without the mold into the space between the mold and liner, and cups fixedly carried by the mold over the inlet end of said ducts for directing cooling medium through the ducts upon rotation of the mold.

16. Centrifugal casting apparatus comprising a mold having tangentially disposed ducts therein, cups ixedly carried exteriorly by said mold for scooping of a cooling medium as the mold rotates so that said cooling medium will tangentially iow through said ducts of the mold into the interior of the mold, a liner, and means sup porting the liner in the mold to permit flfo'w of cooling medium about the liner within the mold.

17. In a centrifugal casting machine the combination of a mold roviding an internally screw threaded soclet, and a liner having exterior screw threads thereon for engagements with the screw threads `of the mold socket so that the liner may be carrier in an ex ansible relation within the mold socket, t e threads of said mold and its liner being so formed as to provide communicating spaces between the mold and liner from one end of the liner to the other.

18. A certrifugal casting machine mold construction comprising a mold having an internally screw threaded socket therein, an externally screw threaded liner for adjustment within the socket of said mold, the` screw threads of said socket and liner being so formed that the `liner may ex and within the mold socket, means yiel ably sup orting the liner in a spaced relation wit in the mold socket, and means for directing a cooling medium through the mold between the same and the liner.

19. In an ap aratus of the class described, an outer cylin rical shell ada ted to be rotatably mounted in a water jac et of a rotary castmg machine, and a cylindrical mold liner secured within said outer shell in spaced relation to the inner surface thereof, comprising an elongated cylindrical shaped body portion and a detachable substantially bell-shaped end portion.

r JOHN RICE.

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