US3193890A - Apparatus for casting centrifugal type pumps - Google Patents

Description

y 1955 H. E. CLARY ETAL 3,193,890

APPARATUS FOR CASTING CENTRIFUGAL TYPE PUMPS Original Filed Nov. 17, 1959 3 Sheets-Sheet 1 19a ,3! Z 25 K4019 I N VEN TORS 507 1395. 61101:; (IQ-56102214. Oil/gg'l BY J c/ ATTORNEYS July 13, 1965 H. E. CLARY ETAL APPARATUS FOR CASTING CENTRIFUGAL TYPE PUMPS 3 Sheets-Sheet 2 Original Filed Nov. 17, 1959 111 INVENTORJ' fiazzz ylf Clary A. ONgg A T F OR IE YS Jas'e aiz y 3, 1965 H. E. CLARY ETAL 3,193,890

APPARATUS FOR CASTING CENTRIFUGAL TYPE PUMPS Original Filed Nov. 17, 1959 3 Sheets-Sheet 3 I N VEN TOR-5 fiarz yi. 6 7013;

' J 0124 OWggZZ BY ATTORNEYS United States Patent 3,193,890 APPARATUfi FUR (IASTNG CENTRIFUGAL TYPE PUMPS Harry E. Clary, Chcsterland, Ohio, and Joseph A. ONeiii, Quincy, IIL, assignors to Thompson Rama Wooldridge Inc., Cleveland, @hio, a cerporaticn of Ghio Griginal appiication Nov. 1'7, H59, Ser. No. 853,649, new Patent No. 3,162,136, dated Dec. 22, 1964. Divided and this application June 22, 1964, Ser. No. 377,031 6 Claims. ((Il. 22-63) This application is a division of our copending application Serial No. 853,649, filed November 17, 1959, entitled Centrifugal Type Pumps, now US. Patent No. 3,162,136, granted December 22, 1964.

This invention relates to apparatus for manufacturing centrifugal type pump bodies by die casting and more particularly relates to die casting apparatus for making the intake portion of the pump housing.

This invention will be described as embodied in the manufacture of a centrifugal pump useful for circulating the cooling water for internal combustion engines of the conventional automotive type. Such pumps are usually driven by a pulley on an externally projecting shaft which extends out through the outer or removable housing portion.

This housing portion is usually of conventional cast iron and encloses at least an end of the pump impeller and its supply or intake chamber (which is usually annular around the shaft) and also includes a transverse passageway extending radially into the chamber. This removable housing has generally been secured on a transaxia-l or transverse parting line to the engine block itself wherein a cavity forms the other or mating portion of the pump housing to enclose the discharge end of the impeller and to include the outlet passageways or volute.

Heretofore, such pumps of the above described conventional automobile types have had unduly high manufacturing costs and had a poor efficiency, particularly as to the flow conditions for the fluid or liquid entering the impeller. Such pump housing portions have usually been made of conventionally cast iron requiring substantial sub sequent finish machining of interior surfaces.

Before the present invention it has not been deemed feasible or economically practicable to manufacture such pumps and particularly their intake housing portions by die casting despite the known desirability and inherent savings of this process. This has been true primarily because of the reentrant surfaces (which have been believed by those skilled in this art to be essential) both in the cavity to receive the pump shaft and its impeller and also in the cavity or recess forming the transverse and intersecting intake passageway.

Previously the liquid entering the impeller has entered from an enlarged or reentrant and annular chamber portion extending all the way around the pump shaft to thus preclude withdrawal of a one-piece or rigid die pin means from either the intake passageway or from the shaft and impeller recess.

According to the teachings of this invention, the two main and intersecting cavities or recesses (and hence all of the cavities or recesses in such casing or housing portion) may be formed without any reentrant surfaces to impede the removal of one-piece or rigid die pins used in die casting. This removal of the die pins is, in one of the preferred embodiments, accomplished by the proper or sequential removal of the die pins for these two cavities. Since the inlet passageway is wrapped, or extends around behind, the cylindrical recess or its impeller entry portion, the die pin for the impeller and its shaft is removed first before the engaging or wrap-around die pin for the intake passageway is pulled out. Both of these main recesses or cavities have either uniform or progressively decreasing cross-sectional areas in the direction moving inwardly from their outer or insertion ends to further cooperate with the removal of the die pin used in die casting. It will be understood that instead of being of a wraparound type, the die pin for the inlet cavity can define about half of the inlet chamber and enter a corresponding slot cut into the axial die pin at this region. Further, as illustrated herein, various die casting methods or different total numbers of die pins may be used herein.

In addition to the advantages of die casting, the pump efliciency itself is increased, particularly in the bettering of the flow conditions of the liquid entering the impeller. These better intake conditions are due to the rotational energy gain in the liquid about to enter the impeller while it is in the impeller entry chamber, which in the preferred embodiment as illustrated herein, is of an annular form around the shaft which pre-rotates the fluid.

The partial wrapping of the tangential inlet passage around the entry chamber also pre-rotates the entering liquid, by the directional characteristics of this volute or scroll-like passageway which is of decreasing cross-sectional areas in its direction of flow to give a progressively increasing velocity and energy gain. This entry form also reduces cavitation and turbulence in the entering fluid or liquid.

An object of this invention therefore is to provide apparatus for die casting pumps of the general type whose inlet casing can be die cast especially from aluminum alloys or other like metals.

A further object of this invention is the provision of an apparatus for die casting pump bodies having a central bore and a generally tangential inlet cavity permitting the use of single one-piece and readily removable die pins in automatic die casting machinery.

A further object of this invention is to provide apparatus for die casting centrifugal pump bodies with the use of removable and reusable die inserts.

Another object of this invention is to provide apparatus for making die cast pump bodies of aluminum or other like metal having the strength of cast iron pump bodies.

Other features, advantages and additional objects of the present invention will be apparent to those skilled in the pump art particularly after consideration of the following detailed descriptions of the drawings in which:

FIGURE 1 is an elevational view of the outer end of a pump assembly constructed in accordance with the principles of the present invention with the drive shaft sectioned and with sections broken away and with certain portions dotted in to show the internal structure more clearly.

FIGURE 2 is an enlarged section taken on the lines 11-11 of FIG. 1 with liquidflow indicating arrows to illustrate the directions of impeller supply flow.

FIGURE 3 is a sectional view showing a somewhat simplified form of the same pump body illustrated in FIGS. 1 and 2 in which, however, the extra and smaller hot water heater water inlet passage is omitted, and in which the transversely extending die pin used in the casting thereof, is shown solid and as partly withdrawn from its operative position, and the axially extending die pin used in the die casting is shown in dotted lines.

FIGURE 4 is a sectional view taken on the line IV-IV of FIG. 3.

FIGURE 5 is a sectional view like FIG. 3 showing another arrangement of the die casting pins.

FIGURE 6 is a sectional view like FIG. 3 showing still another form and arrangement of the die casting pins.

FIGURE 7 is a sectional view taken on the line VII-VII of FIG. 6.

FIGURE 8 is a sectional view like FIG. 3 showing another arrangement of the die casting pins.

housing.

The reduced diameter portion 21 of the through a seal 36 including a cup me1nber'32 Withan engine water circulating pump in which the outer or intake portionfof the pump housing or casing is designated by f the reference numeral 1 in FIGS. 1 and 2. The casing is a one-piece metal casting shaped according to the teachings and advantages of the method of this invention and this'orsimilar housingsniay be made economically as one-piece die castings; preferably of aluminum alloy or other light metals by the method of this invention.

The housingllhas a flat face 3 adapted tobe secured and sealed with a suitable gasket as by screws or studs through holes such as 5 in the bosses 6 which are threaded into sockets or holes in the engine block-itself which forms the other or remaining portion of the pump housing and includes the conventional outlet or discharge passages therefor, as will be well understood by those skilledin this art.

t .The pump ofiElGS fl and 2 has a plastic blade portion 9 for forcing fluid flow into a volute chamber or the like andrthen ce through one or more distribution passages to the severalregions to which the cooling water is'to be supplied. The plastic portion 9 has a central hub 16 memberSl is eliminated.

a passage52 extending therethroughinto the pump inlet cavity as is provided. 7 V

in FIGS. 3 and 4 the same reference characters used in describing FIGS. land 2have been repeated except that they have beeni'ne'reased by 400. In FIGS. 3 and 4. the structure is'intended to be identical with that described'in'FIGS. l and 2 exceptthat the pump nipple As shown in FIG. 3 the entire axial bore comprising the conicalfsurface 412 and the cylindrical surfaces 436, 43s and 425, which are of progressively decreasing diametergcan be readily formed by die casting since a one- .piece' steel die pin 481 can form all of these surfaces to e a high. degree of accuracy and can be readily withdrawn receiving the reduced diameter end 17 0f a metal. cylin- 1 drical hub 19 to form a combination plastic and metalimpeller and shaft unit designated as a whole by the reference numeral 10. Theblades of the plastic impeller portion 9 extend radially and discharge the liquid from their tips 15 after receiving the liquid at cutaway portions 14 which give a better liquid entry flow condition.

The blades have .frustoconical'end edges on their intake ends which are partlywrecessed into a cavity 12 of the The metal hub 19 is 21. of thepump shaft 22 which, as shown, has an annular' groove 23 therein, several successively larger diarn eter portions between the end 21 and an enlarged diameter bearing portion 24 secured in the bore 25 of the casing 1. The shaft projects at 26 from the bearingZd.

and may be secured to the fan of the automotive engine 7 and to a pulley for the usual belt drive. I

shaft extends outward extending lip33 and an annular recess opening 34 facing the hub 19. The lip member 33 is botaffixed on the; smaller diameter end I The ,seal ring 40 is confined in a" is resiliently held against the smooth flat and seal forming surface 19a'on the hub 19. The seal member can be composed of suitable material such as carbon, a ceramic, or a thermosetting plastic mixed with metal and graphite. V I

The casing has an enlarged flange portion 44 with the flat surface 33 on one face thereof. This portion 44 is connected by .a tapering outer portion 45 to a reduced 1 diameter portion 46 containing the bearing receiving bore 25. A'tubular intake passage 48 is formed and has at least in its inner end portion a progressively decreasing cross-sectional area diminishing in the direction of liquid flow and as indicated at'Sll and leading into the entry chamber 36. p e V The pump casing 1 may also include the conventional means for return of heater water into the pump intake and as shown a nipple of cylindrical extension 51 with the inlet cavity.

to the right as indicated in dotted lines. While only the die pin 43]. is shown itwill be appreciated that this type of an axial bore can readily be die cast in an automatic H die "casting machine.

As shown in FIG. 4- a die pin 482 extends through the nipple 443 and has a'hooked or curved portion 483 adapted to be positioned around the die pin 481. It will be understood that the die pin 481 must be removed to the dotted line position of FIG. 3 before the die pin 482 can be. removed. The hooked. or curved portion .433 of the'die pin 482 defines the outer surface for the impeller inlet cavity which is of progressively decreasing cross sectional area and wraps or extends around the shaft in the form of a partially shaft enclosing annular chamber to impart a whirl or rotation in one direction only to the entering water. As illustrated the portion 45% merges with this annular portion 454 as shown in FIG. 4. Passage 450 is preferably tangential to the pump inlet cavity 436. K p

Referring toFIG. 4, it will be noted that the passage 450 is shown as being at approximately to the pump shaft axis, but it should be understood that this direction may be changed without losing major benefits of therpresent invention. Thus the extension 448 may be inclined to the left as seen from FIG. 3 so that the angle between the driven end of the pump shaft and the axis of this passage is less than 90 thereby adding a higher axial component to the velocity of the liquid entering To enjoy all of thelbenefitsof the present pump construction and invention the entering liquid should be rotated or swirled in the direction of the pump rotation by two dilferentmeans. First, the entering liquid should be rotated by the tangential and the partially wrapping orpartially annular inlet passageway 450 and its inner inlet cavity and wrapping portion. Secondly, the entering liquid is 4 preferably rotatedby the rotary drag of the shaft itself.

' It will be seen from FIGS. 1 and 2 that the liquid in the inlet cavity 36 will be rotated or dragged around in the direction vof shaft rotation by the shaft or its hubportions and related structures. .This is in contrast to the loss of this frictional drag energy in a conventional form of pump-wherein only one-half of the annular recess can be in the direction of shaft rotation while the other half will have its flow direction opposed to 7 that of the shaft rotation.

The advantages of die casting for automotive parts or for any mass produced partsare well. known and even with the use of more expensive aluminum alloy instead of previously used cast iron the process of. this invention gives rise to substantial savings in the overall cost of I the finished parti It'has been reliablyestimated that a pump intake housing portion made according to the present invention for a competitively priced small American mass produced automobile results in a saving of from 30 to 35 cents apiece in this highly competitive andhighly developed art. a

As shown in FIG. 1 the blades of the blade unit 9 are tipped backward and the operating theory relating thereto indicates that'the'rnaximum theoretical pressure -means described above.

obtainable at the pump outlet is slightly reduced by the pre-rotation given to the entering liquid by the two This slight pressure loss or velocity gain can readily be compensated for by either increasing the outer diameter of the impeller or by running the pump faster. However, in lieu of these solutions it is usually preferred to increase the pumps inlet vane angle which is shown by the angle B in FIG. 1 and is the angle between the tangent to the root of the blade and the root section of the blade. Accordingly, in the case of the present invention this angle B will be preferably increased over the value for the similar angle which would be used in a pump of conventional design and form. An increase in the overall efficiency is gained by this increase in the engine vane angle.

It is also to be understood that the pump body structure or form may be formed in various other ways or by other die casting methods or arrangements of die pins in the die casting machine. For example, as shown in FIG. 5 v(in which the reference characters, except for the die pins, are the same as those used in the pump structure of FIGS. 3 and 4), the entire axial bore may be formed or defined by two pins instead of one. Here the central bore is formed by die pin 58111 which is preferably fixed in the more or less stationary or fixed cavity forming part of the die in the die casting machine. Pin 581b, defining the rest of the central bore, is preferably attached to the movable or sliding ram or cavity closing portion of the die casting machine. It may be desirable to have the fixed pin 581a shorter and rigid to end at the end of the seal cavity 438. It is to be noted that this pin arrangement permits the bearing bore 425a to be larger in diameter than the seal cavity 438 which may be desirable in some applications. It will be understood that in all of these cases the draft of the various cavities will be conformed to the direction to which the pin is to be pulled.

The inlet passage forming transverse die pin 582 is preferably actuated by an auxiliary moving ram (not shown) which, in this case the automatic die casting machine would be arranged to move the auxiliary ram and pull pin 582 only after pin 5811: had been removed. The interrelated method of die casting will be apparent from the foregoing and it may be noted that the form or shape of the inlet passage and extension 448 may virtually be of any shape as long as its pin can be withdrawn after the cast metal solidifies. Preferably the outer end will be circular for attachment to the usual hose.

In the embodiment of FIGS. 6 and 7, the reference characters, except on the die pins, are the same as those used in FIGS. 3 and 4, but in this arrangement the central or axial bore may be die cast by a method using two die pins 681a and 68112, as shown. These two pins meet at the junction of the seal cavity 438 and the bearing bore 425 which may thus be smaller in diameter than the seal cavity as is usually desired.

In the arrangement of FIGS. 6 and 7, there is still an embracing or surrounding relation between the pins for the inlet passage and the inlet chamber generally as in FIGS. 3 and 4, but here the pin 681b is notched or slotted as shown at #633 to embracingly fit or receive the curved end 685 of pin 682a which thus defines a half orsome otherfraction of the circumference of the inlet chamber. In this method therefore pin 682a will be withdrawn or pulled first by its auxiliary ram in the automatic die casting machine to thus permit the timed and subsequent withdrawal of pin 681!) preferably with or accompanying the opening of the movable part or closure of the die itself.

As illustrated in FIG. 8, which is otherwise like FIG. 6, the above described die casting method may be carried out by the use of only one die pin such as 781 which is 6 removed from the larger or open impeller end of the pump body like the pin 481 of FIG. 3.

It is to be particularly noted that the two passageways or main recesses opening into the pump housing 1 are communicating and generally transverse to each other. Both are die cast into this housing portion. In order to more readily define the non-reentrant or the non-internally enlarged nature of the internal surfaces of these two intersecting passageways or to thus define a die castable surface in which a single rigid die pin may be used, such passages or surfaces may herein be defined as permitting the withdrawal of a one-piece or integral die pin in the die casting machine or process. Thus this definition means that all such internal surfaces are free of any reentrant internal surfaces which would preclude such rigid pin die casting.

Attention is also directed to the fact that these two openings or recesses are each of either uniform or of progressively decreasing cross-sectional areas from their outer or die pin withdrawal ends and thus permit the ready withdrawal of a one-piece die pin. This type of internal surface according to the present invention is herein defined for the purposes of this application and its appended claims as one in which all internal or interior cross sectional areas and surfaces are at most equal to succeeding cross-sectional areas inward from the open or pin entry end of such recesses.

It will be understood that terms such as one piece or rigid as used herein are intended to embrace or include the optional casting into the pump casing member of suitable inserts or the like including a seal face insert of ferrous material to form one seal face against a seal cartridge assembled on, and rotating with, the impeller as is well known in this art. It is further to be understood that, while the one piece structure, as defined, is preferred yet this invention is not so limited and may be used to advantage in multi-piece assemblies.

Suitable apparatus for die casting the aluminum housing or casing of FIGURE 3 is illustrated in FIGURE 9. As therein shown, the housing 401 is formed in a die cavity C provided by a fixed die A and a movable die B. The die pin 481 is illustrated as fixedly mounted on the moving die and forms the conical surface 412 and cylindrical surfaces 436, 438 providing the liquid entry chamber and seal chamber of the casing. A cylindrical die pin 481a is slidably mounted through the fixed die and forms the bore 425 in the bearing extension 46 of the casing. A die pin 482 is also slidably mounted in the fixed die A and forms the passageway through the nipple 448 with its hooked or curved portion 483 fitting around the die pin 481 to coact therewith in forming the annular inlet portion 454. Metal is supplied to the apparatus through a suitable entry E and gate G by a plunger P. Each of the die pins is retractable from the cavity C in a straight line path with the pin 481 first being withdrawn so that the hooked end of the die pin 482 will be released.

It will be understood that the features and advantages of the present invention may be utilized only in part and that various changes or modifications as well as other applications hereof may become apparent to those skilled in this art and used within the scope of the contributions and the novel concepts of the present disclosure, which is to be limited only by the scope of the appended claims.

We claim as our invention:

1. Apparatus for casting a centrifugal impeller pump housing having a generally annular main body portion with a fiat peripheral flange at one end, a tubular exten sion at the opposite end and a laterally projecting nipple intermediate the ends which comprises: a die having a cavity for externally shaping said housing, a first die pin extending into said die cavity from the flange-forming end thereof having a tapered face for forming a frusto-conical recess in the flange, a cylindrical portion for forming a cylindrical chamber in the main body extending from the bottom of the frusto-conical recess and a fiat shoulder v for forming'an end wall for said chamber, a second'die pin projecting into the die; cavity from the nipple forming portion thereof having a ,main body for forming theinterior of thenipple and a curved leading end projecting into'thec avity around the cylindrical portion of the first pin tov coact with the first pin in forming a tangential recess'fo'r directing liquid from the nipple into the chamher with a whirling action, and a third pin, aligned'with the first pin and projecting'from the opposite'end of the die cavity to coact with the first pin for defining a reduced diameter passageway communicating with the chamber in axial alignment therewith.

2; Apparatus for die casting a pump body or the like with a pumping chamber having a side inlet merging into the pumping chamber through a curved recess and a seal chamber inwardl'y'from the pumping chamber which comprises: "a mold having acavity shaped to .definethe exterior of the body, a firstdie pin projecting into the cavity of said mold having a first cylindrical portion to form the pumping chamber in the body and asec'ond and reduced cylindrical portion to form the seal chamber, in

the body, saidfirst die pin having a recess in the endface thereof, a second die pin projecting into the cavity at an angle to the first die pin to form the side inlet to the body, said second die pin having a leading'end seating in the recess of the first die pin, said loading end of the second die pin having a curved exterior surface converging into registration with theexterior. surface of said first die pin to form the curved'recess in the body joiningthe side inlet with the body, and means for removing said die pins from'the cavity, said means, including a-straight line re moval path for at'least said second die' pin.

3. Apparatus for casting a one-piece cylindrical type liquid pump entry housing having arecessfor the inlet and shaft end of a centrifugal pump impeller, an inner- 5." Apparatus for manufacturing one-piece entry housings for engine coolant centrifugal pumps which housings have'end flanges for attachment to the engine, :body portions extending from the end flanges, lateral nipples on the bodyportio'ns and bearing support portions projecting from the body portionsflwhich comprises: 'a die casting mold with a cavity shaped toform said flanges, body portions,'nipples and bearing support portions, first die pin means projecting into said cavity shaped to :form in the housing an opening through the end flange, 'an entry chamber in the body aligned with said opening, a bore through the bearing support portion and a seal recess between the entry chamber and bore, second die pin means projecting intosaid cavity shaped to form a passage through the nipple, said firstzandsecond die' pin means having matedtogether faces blocking otf flow of casting material between the pin means and providing an opening joining the nipple passage with aside of the entry chamber,

- and straight line guide means for, retracting said die pin means along substantially straight line paths from the casting formed in the'cavity and'from the cavity to permit removal of the casting from the mold.

6. Apparatus for die casting'metal entry housings for engine coolant pumps which housings have aflat end flange for bolting onto an engine block, a body extending axially from the flange, a bearing support portion extending axially from the body, a laterally extending nipple, ribs radiating from the body to the-flange, a central opening through the flange, a generally cylindrical entry chamber coaxial reduced diameter generally cylindrical liquid; 1 entry chamber extending into said recess, a shaft receiving bore extending through 'the housing portion and a liquid intake passage extending tangentiallyinto and embracing one side of the entry chamber which comprises a die mold having a cavity shaped for defining the exterior of said housing, first die pin means projecting into said cavity and defining all of said bore, and recess, s'econddie pin means extending into said cavity defining said pas sage, said'first andsecond die pin means having mating portions preventing metal flow therebetween and when mated, together providing surfaces which form the entry chamber and a merging passagewaybetween said passage and the entry chamber, and saiddie pin means being removable in a straight line path from said cavity'to accommodate removal of the casting housing from the mold. 4. Apparatus for forming one-piece aluminum entry housings for engine coolant centrifugal pumps which housings have end flanges for attachment to the engine,

body portions extending from the end, flanges, lateral nipples on the body portions and bearing support portions projecting from the, body portions which comprises: a

in the body extending axially from said opening, a bore through the'bearing support porti0n, a seal recess between the entry chamber and bore, and a passageway through the nipple opening into the entry chamber which comprises a mold havinga cavity shaped to define. the flange,

body, bearing support 'portion,nipple, and ribs, a first die pin extending axially into said cavity from the flange forming end thereof shaped to form the opening through the flange, the entry chamber and seal recess, a second die pin extendingaxially into said cavity from the-bearing mold having a cavity shaped to form said flanges, bodyportions, nipples and bearing support portions, first die,

pin means projecting through the cavity to define an opening through the flange, an entry chamber in the body and a bore through, the bearing, support, second die pins means projecting into the cavity to define a passage through the nipple, said first-and second die p'in means having interfitting portions inthe body'forming portion of the cavity-enacting to define a tangential inlet recess extending from the nipple passage around-one side of the entry chamber, and said die pin means being retract? able along straight line paths from the casting formed in 'the cavity and from the cavity to permit removal of the casting from the mold.'

Q MARCUS U. LYONS, Examiner.

support portion forming end thereof and aligned axially with the first die pin, a third die pin extending laterally into the cavity from the nipple forming side thereof, said first, second and third die pins-havingmating end portions to' prevent metal flow therebetween and when mated together providing surfaces which form the opening, the

entry chamber, the bore, the seal recess, the nipple passage, and a merging passageway between the nipple pas sage and entry chamber, and straightline guide means for retracting said first, second and third die pins along straight line paths from the casting formed in the. cavity and from the cavity to permit removal of the casting from the mold.

References (Iited by the Examiner pages 66-71, 103-105, 129, 130. a I H Die Casting by Herb, FirstEdition published 1956, pages 76-78.

J. sPENcER OVERHOLSER, Primary Examiner.

Claims (1)

1. APPARATUS FOR CASTING A CENTRIFUGAL IMPELLER PUMP HOUSING HAVING A GENERALLY ANNULAR MAIN BODY PORTION WITH A FLAT PERIPHERAL FLANGE AT ONE END, A TUBULAR EXTENSION AT THE OPPOSITE END AND A LATERALLY PROJECTING NIPPLE INTERMEDIATE THE ENDS WHICH COMPRISES: A DIE HAVING A CAVITY FOR EXTERNALLY SHAPING SAID HOUSING, A FIRST DIE PIN EXTENDING INTO SAID DIE CAVITY FROM THE FLANGE-FORMING END THEREOF HAVING A TAPERED FACE FOR FORMING A FRUSTO-CONICAL RECESS IN THE FLANGE, A CYLINDRICAL PORTION FOR FORMING A CYLINDRICAL CHAMBER IN THE MAIN BODY EXTENDING FROM THE BOTTOM OF THE FRUSTO-CONICAL RECESS AND A FLAT SHOULDER FOR FORMING AN END WALL FOR SAID CHAMBER, A SECOND DIE PIN PROJECTING INTO THE DIE CAVITY FROM THE NIPPLE FORMING PORTION THEREOF HAVING A MAIN BODY FOR FORMING THE INTERIOR OF THE NIPPLE AND A CURVED LEADING END PROJECTING INTO THE CAVITY AROUND THE CYLINDRICAL PORTION OF THE FIRST PIN TO COACT WITH THE FIRST PIN IN FORMING A TANGENTIAL RECESS FOR DIRECTING LIQUID FROM THE NIPPLE INTO THE CHAMBER WITH A WHIRLING ACTION, AND A THIRD PIN ALIGNED WITH THE FIRST PIN AND PROJECTING FROM THE OPPOSITE END OF THE DIE CAVITY TO COACT WITH THE FIRST PIN FOR DEFINING A REDUCED DIAMETER PASSAGEWAY COMMUNICATING WITH THE CHAMBER IN AXIAL ALIGNMENT THEREWITH.

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