US2790217A

US2790217A - Casting machine

Info

Publication number: US2790217A
Application number: US291410A
Authority: US
Inventors: Squire D Tyler
Original assignee: Eaton Manufacturing Co
Current assignee: Eaton Corp
Priority date: 1952-06-03
Filing date: 1952-06-03
Publication date: 1957-04-30
Anticipated expiration: 1974-04-30

Description

April 30, 1957 s. D. TYLER CASTING MACHINE n 5 Sheets-Sheet l Filed June 3, 1952 o o o o NN MYN \\N\ NN m QW m um I. L Il l. n n mv@ um RQ M. \Q\ v o o WMA o .lo

April 30, 1957 s. D. TYLER 2,790,217

CASTING MACHINE Filed June 3. 1952 f 5 She'ets-Sheet 2 INVENTOR. Sauz're E 7;;/ez'

April 30, 1957 s. D. TYLER 2,790,217

CASTING MACHINE Filed June 3, 1952 5 Sheets-Sheet 3 Wg/@Mza April 30, 1957 s. D. TYLER CASTING MACHINE Filed June 3, 1952 5 Sheets-Sheet 4 April 30, 1957 s. D. TYLER CASTING MAcHxNE 5 Sheets-Sheet 5 Filed June 3, 1952 LEI.

United States Patent O CASTING MACHINE Squire D. Tyler, Vassar, Mich., assigner to Eaton Manugalturing Company, Cleveland, Ohio, a corporation of Application June 3, 1952, Serial No. 291,410

4 Claims. (Cl. 22-90) The present invention relates to a machine for the casting of molten metals and to suitable mold fixtures for use in connection therewith. More particularly this invention is concerned with the casting of molten metal in shell molds which are suitably supported by and positioned on multi-station rotatable turret type machines.

In the past, permanent mold casting machines embodying a plurality of cast iron molds carried by a rotatable turret-type frame structure have been used extensively in the casting of molten metals, particularly ferrous metals such as the casting of gray iron parts, etc. Cast iron permanent molds for such machines are customarily provided with the necessary cavities and projections to form the desired casting, and in use, the surface of the mold is first coated with a heat resistant adhesive of the general type disclosed in U. S. Patent 1,935,362, and second a parting layer such as graphite. After each casting is made in the mold, it is necessary to thoroughly clean the mold surface and to apply a new parting layer coating before again using 4the mold. One of the more important disadvantages of such permanent molds is that the castings which can be made therein are limited to relatively small sizes because of the problem of dissipating the heat from the molds. lt is economically impractical in the quantity production of castings with this type of molds to make castings larger than about fourteen pounds in weight. Even when the casting size is maintained below this weight limit, the life of the molds is comparatively short.

The term shell mold as used in this speccation and the appended claims is intended in its broad sense to include any relatively thin walled, self-supporting mold fabricated from conventional foundry sand and a resinous binder. It is commonly known that in order to cast molten metal in thin walled shell molds, that it is necessary to provide some type of exterior support for the molds. It has been suggested that loose shot or the like maybe used to support the rear surfaces of the cope and drag or inner and outer sections of the mold. Such procedures are expensive and do not adaptthemselves to quantity production'or to the production of castings of large size.

It is, therefore, the principal object of this invention to provide an improved casting apparatus having provision for supporting shell molds thereon whereby the disadvantages of using permanent molds may be overcome and the casting of metallic parts in shell molds rendered feasible in production quantities.

Other objects of the invention include the provision of a casting apparatus which is improved by having a shell Y mold holding fixture and associated structure which insures adequate support for the shell molds and enables the manufacture of a variety of shapes of castings without limitation of the size thereof; the provision of an iniproved casting apparatus having shell mold supporting fixtures providing full support for the entire rear surface area of shell molds supported therein; the provision of an improved casting mold apparatus providing for the ilow of'cooling air over the surfaces of shell mold sup- 2,790,217 Patented Apr. 30, 1957 porting fixtures heated during the casting operation; the provision of a casting apparatus improved by provisions for automatically ejecting the casting from the shell mold and associated supporting fixtures.

Additional objects of the invention includes the provision of means for supporting one part of a multi-part shell mold supporting assembly so as to enable it to be advanced toward, or retracted from a cooperating portion; the provision of power means for moving one portion of a shell mold supporting assembly into and out of cooperative vrelation with respect to another portion thereof for supporting a shell mold between; and the provision of a shell mold supporting assembly including a pair of separable supporting fixtures and a cooperating track, one of the fixtures being wholly supported on the track and being movable thereon into and out of cooperative relation with the other of said portions by power means.

Further objects and advantageous features of the invention will be hereinafter specifically pointed out or will become apparent upon considering the present disclosure in its entirety.

Casting machines of the present invention comprise a relatively large generally circular supporting frame structure or turret and suitable means for rotating the same about its vertically disposed axis. A plurality of uniformly spaced shell mold supporting assemblies are provided adjacent the periphery and rotate with the turret. Each shell mold supporting assembly comprises a pair of supporting fixtures which cooperate with each other to support a shell mold therebetween. The shell mold supporting fixtures vary with the required amount of support of the shell mold as will hereinafter be more fully brought out. In a casting operation, the shell mold maintained between the supporting fixture halves substantially loses its identity as a unit due to the charring or conversion of the binder of the shell mold to a weak, crumbly state from the heat of the cast metal, and the mold may be easily separated from the resultant casting by simply shaking or jarring the casting. Each casting requires a new shell mold, the shell molds being fabricated separately and inexpensively. .Inasmuch as the molten metal contacts only the shell mold, the shell mold supporting assemblies have an extremely long life.

Each shell mold supporting Yassembly comprises a relatively stationary fixture with respect to the rotatable turret of an automatic casting machine of the type herein described, Vand a cooperating fixture movable with respect thereto, the two fixtures cooperating with one another to support a shell mold therebetween and to retain the same vduring a casting operation withoutV crushing it. When such supporting assemblies are employed in conjunction with a casting machine of the type herein described, means are provided for maintaining the two fixtures in cooperating contacting relationship during a portion of each rotation of the turret. Means are additionally provided to separate the supporting fixtures during another portionof each complete rotation of the turret. Molten metal is poured into the shell mold maintained between the cooperating supporting fixtures during the portion of the rotation of the turret when the xtures are maintained'in contact with each other. The fixtures are separated from each other after the metal poured has solidied sufficiently to enable the ejection of the cast article, and the fixtures are maintained in separated relation un- 'ice til a point in the rotation of the turret immediately precedi Y ly spoked frame structure.

3. large castings, these modifications providing intermediate proportions of shell moldisupp'ortor cmplete'suppor't of the rear surfaces of the shellmolds. As the proportion of the rear surface of the shellmold whichis supported by actual contact with metallic portions of the supporting fixtures is increasedpthe heat transmitted through the mold to the fixtures likewise increases. While the quantity of heat transmitted through the shell mold'wall to the fixture is in all cases much less than is absorbed Aby permanent molds, for extremely large castings it is preferred and means have been provided for cooling the shell supporting fixtures. The supporting fixtures are each so constructed that air may be caused to continually flowV over the rear faces of the supporting fixtures and cooperating means is provided to maintain aow of air thereacross.

In the drawings:

Figure l is afragmentary top plan view ofa casting machine embodying the present invention;

Figure 2 is a fragmentary vertical sectional View taken axially through the castingmachine illustrated in Fig'. l;

Fig. 3 is an enlarged horizontal View through one of the shell mold supportingv assemblies taken along the line 3 3 of Fig. 2;

Fig. 4 is a vertical sectional view illustrating the disposition of shell mold supporting and retaining means taken along the line 4 4 of Fig. 2;

Fig. 5 is a vertical sectional view taken on the line 5 5 of Fig. 2 showing the disposition of supporting and yieldableretaining means;

Fig. 6 is a vertical sectional view taken along the line 6 6 of Fig. 3 and looking in the direction of the arrows;

Fig. 7 is a vertical sectional view taken along the line 7 7 of Fig. 3 and looking in the direction of the arrows;

Fig. 8 is an enlarged, horizontal sectional view of a shell mold supporting assembly of the type illustrated in Fig. 3 and showing a modification thereof;

Fig. 9 is an enlarged, horizontal sectional view of a shell mold supporting assemblyof the type illustrated in Fig. 3 and showing an additional modification thereof;

Fig. l0 is an enlarged horizontal sectional view of a shell mold supporting assembly of the type illustrated inFig. 8 and showing a modification thereof; andf Fig. 1l is a vertical sectional view taken along the line 11 11`of Fig; l0.

Referringto the drawings in greater detail, it may be seen in Figures 1 and 2 that there-is provided a casting machine which includes a suitably fixed supporting base orv structure indicated generally at 15 which base is provided with a fixed vertically extending. cylindrical post 1'7. Rotatably'mounted upon the post 17 is a drum-like member 19 which forms the central member ofthe rotatable turret. Member 19 is provided with a suitably hushed central hub 21V which rotatably receives the post 17 for guiding the drum member 19 in its rotating movement. The thrust of the turret is absorbed by suitable thrust bearing elements 23 disposed between the drum member 19 and the supportingV base 15.

A plurality of radially extending equally angularly shaped supporting arms 25 are'rigidly secured tothe peripheral surface of the drum 19 and project radially outwardly therefrom; the outer ends of the arms 25 are connected by cord members 27 andthe cord members 27 together with the arms 2.5 form a generally'circular radial- The armsZS are hollow and the hollow interiors are in open communication with the interior of the drum member19. The upper end of the drum member 19 has suitably secured to its upper edge anannular plate-like member 29'which extendsv radially inwardly from the outer edge thereof. Plate member 29 has secured thereto adjacent its inner edge, anV upwardly extending circular housing 31 and forms the sole support therefor. Circularhousing-Sl'isprovided with an annular cored passage 33 therein Which'- serves'as al distributing duct for compressed air which is used to actuate the movable porfion'of the shell`supportiiigassenibly` The upper end of the hub 21 of the drum-like member 19 is closed by a cap member 3S, the interior of which is divided into completely separated upper and lower chambers by means of a crosswall 37. The interior of the duct 33 in the member 31 is connected by means of a pipe 42 with the interior of the upper chamber in the cap 35. The interior of cap 35 additionally communicates with a suitable source of commpressed air unsuitable motive fluid by means of a tube43, elbow 4S and upwardly extending pipe 47.

Spider 49 is suitably rotatably'fsupported upon the upper end of the cap 35 and terminates at its periphery in a ring 51, the lower edge' ofy which is so constructed and arranged as to cooperate with the upper edge of the housing member 31 so as to minimize the leakage of air therebetween. A stack or flue 53 is attached to the upper-edge of thering 51 and serves as the flue through which-'air employed in the cooling of the mold'is withdrawn. vertically disposed stack 53, spider 49' and ring 51 remain stationary during the rotation of the turret.

In order to secure the rotation of the turret, the lower face of ydrum member 19 has an internal gear 55 concentrically secured thereto. A transmission mechanism including a casing 57 rigidly fixed with respect to the base 1S and a spur gear 59 lying in mesh with thegear 55 is employed for rotating the turret. The gear 59 is fixed upon a vertical shaft 61 rotatably mounted in the casing`57 and within' which has fixed thereto a ring gear 63. r[boring gear 63 meshes with a pinion 65 fixed upon the rigidly extending-shaft 67 which is rotatably mounted within the casing 57 Yand one end of which projects therefrom and receives thereon a coupling member 69. The coupling member @is employed for connecting the shaft 67 to one element of a' variable speed device of known construction including elements 71 and 72, which are connected together and adapted to be driven by the electrical motor 75 of the synchronous or constant speed type. The motor 75 and speed reducing units 71, 72 are fixed insuitable aligned relation upon a common base 77. It'will be appreciated that the speed of rotation of the turret'rnay be controlled as desired by conventional adjusting meanscp'rovided inconnection with the speed reducing4 units 71, 724 and that the turret is preferablyV rotated" at a speed as fast as will produce the desired quality Yof cast'article. Y Y

Theftu'rret is-provided with a plurality of identical shell mold supporting assemblies, eachv assembly being supported`between thel outer ends of each adjacent pair of arms 2'5. Each shell mold supporting assembly includes a fixture stationary with respect to the turrets and `an opposedmxture movable relative to the turrets. Each fixture includes an inner plate-like member and a support. As shown in Fig. 2, inner plate-lilre member 79 is secured by means of ybiolfsi'lk to a vertically extending support 85and together" constitute theV stationary fixture generally designated`i9'0`. Similarly,v inner plate-like member 81 is seeuredby means of boltsV 83 to vertically extending support'89'and together constitute the movable fixture generally designated 92.

The suppor't8'9 'is'fixedas by bolts-91to the upwardly extending flange 93 o'fa carriage including a pair of spaced parallel arms 95 `arranged-in generally radial relation with'resp'eettdtheaxisV of rotation of theturret and theoute'riandinner ends of which each rotatably support a grooved roller 97. The groove rollers 97 ateachv side of the`ca'rriage95Y` are received upon corresponding rails 99. The rails" 99 are' supportedfrom the arms 2S by Ameans of a plurality of .cross-bars 101 extends between andfixed to the lower facesof the cooperating pairV of armsZS.'

As may best' be seen inFigs. 4' and 5, inner plate-like members79g 81 are provided with'a-plurality ofinwardly 'projecting pins; thefunction'of which is to support and :Lg-"vessie maintain a shell mold generallydesignated184 between'tle fixtures 90 and'92. As shown, shell mo1d8`4`is'com-'- prised of cope and drag or outer and inner sections' 86; 88, the inner surfaces thereof dening a mold cavity 82. Member 81 which moves toward and away frommember` 79 is provided with a plurality of dowel pins 103 iixed cylindrical pins 106, the at surfaces of which conform toV theoutline of a shell-mold 84 supported thereon.v Pins 106 enable the rapid and accurate positioning of shell' mold 84 on the stationary plate-like member 79 by the operator duringthat portion of the rotation cycle of the turret when the fixtures are separated. As will be noted, the remaining pins in stationary and

movable members

79, 81 are positioned in corresponding locations and occur in opposed pairs, the pins in stationary plate 79 bearing correspondingly primed numbers to designate thecorrespondence. Pins 108, 110, 112,114, 116, 118, 120, 122 and the opposed primed numbered pins on plate 79 are yieldably supported and are slidably received-'by corresponding apertures in the

plates

81 and 79 respectively. As best seen in Fig. 6, the yieldable loading ofthe pins is accomplished by providing the outer' ends! of pins 122, 122with enlarged diameter shoulder' portions 122:1 and 122a' and outwardly projecting stub sections `122b1 and 122b adapted to accommodate.springst124, 124 which are positioned therearound. The outer-ends of. springs 124,- 124 encircle andare supported by inwardly extending

stubs

125, 125 portions 123, 123'. The outer ends ofstuds 125, .125 are anchored in corresponding apertures in'vertically disposedvplates 126 and 126 respectively. Itv will beiapparent

thatpins

122, 122 may move through

innerplatelike members

81 and 79 against the tensions of springs 124 and 124', and will be maintained by

springs

124, 124"V in atrest positions wherein

shoulders

122a and 122a are positioned in

blind recesses

121 and 121 in members 81fand 791respectively. Plates 126, 126' are clamped between the at face of each support 85 or 89 and the cooperatingiinner plates `79 or 81 -by bolts 83. The inner ends of

pins

108, 110, 112, 114, 116, 118, 120, 122-are in direct abutment with the rear surfaces of the .cope and drag sections- 86, 88 of the shell mold 84 and yieldably maintain the same in position without crushing or otherwise rnarrinu or deflecting the inner surfaces thereof. It is to be understood that the number of yieldable pins and their location may vary with'the location of the recessesV and projections in the shell mold surfacesA as well asthe-relative size of the object to be cast. In general, thev number of pins is preferablyv increased with increasing size of the casting and the location ofthev pins- 1s preferably at points which are remote from .therecesses or projections on the surface of the shell mold wh1ch 1s to be contacted by the pin ends. The positioning of pins at points immediately adjacent to points of change of contour of the shell moldtends to accelerate mold breakdown where the pin .ends do not conform to the mold contours and should be avoided.

For the casting of somewhatlarger objects of intermediate size such as objects weighing about fifteen to twentyfive:y pounds, it is usually desirable to provide reinforce- -rnentfor a greater proportion lof the area of the shellmold than is provided by :the spaced cylindrical pins as described above. Fig. 9 illustrates a modified embodiment suitable for the acomplishment of this objective.- As there showma single cavity mold 140 having a relatively large cavity 142and thin shell inner and outer sections 141,` 143 which are positioned in abutment with semicylindricalpins1144,145 carriedby and rigidly secured to stationary inner plate-like member 146: Shell mold 140 is partially retained in position by opposed pairs of and rest against studcollarf.

6 s Y i spring 'loaded'pins 148ii 148 andv 150,l 150'` positioned adjacent'theside extrernitiesv 'of the mold. The central portion of mold'v surrounding cavity 142 is reinforced by two sets ofpin'memb'ens 152, 152 and 154, 154. The inner ends -of pinsi152, 152" and 154, 154 are provided

ywith extensions

153, 153' and 155, 155 respectively, which areshaped or contoured to conform to a portion of the shape-of the projections on the rear surfaces of the mold 140.v As explained above in connection with .the spring loaded-pinsvof Fig. 6, the

pins

148, 150, 152, 154 andthe opposing prime numbered pins likewise act against `the ten-sion of suitable springs positioned on their outer extremities andxabutting against

rigid plates

156, 158.

In-the casting-of vextremely large-objects or of objects having localized* weight concentration so that adequate support may not be accomplished conveniently by either of the foregoing described supporting assemblies, the assembly illustrated in Fig. 8 may be advantageously used; As Athere illu.strat'ed,`the shell mold supporting .assembly comprises a pair of fixtures generally designated 210 and 212.

Fixtures

210 and 212 .are provided with inner platelike members 211- and 213 which :are detachably secured to stationary support 214 and movable support 215, respectively. Inner plate-like members 211 Aand 213 .are contoured on'their inner faces to correspond tio and to cooperatively nestle against and to lie in full labutment with the entire rear surface of the shell mold halves 217, 219deining-oavity 282.` For the purposeof supporting the shell mold and attaching the same to :the stationary inner plate-like member 211 when movable inner platelike "member is separated therefrom, there Iis provided on the'l outer lor rear surface of shell mold half 217, a pair of outwardly projecting

bosses

221, 223 which ane received by corresponding apertures in the front face of inner plate-like member 211. Mold half 219 is suitably grooved :to mate with mold half 217 `so that they from a unitary mold when assembled and positioned in contact with-the' inner face of the 'member 211. Becauseof the direct contact between the rear surfaces of the mold halves 217, 219 and the :abutting inner plate-like members 211, 213, respectively, a greater proportion of heat from the molten metal being'cast in the shell mold is transmitted tto the members 211, 213 than in the above described pin types ofsupporting'assemblies. In 'order to enable the continuous quantity production of large objects and to concurrently maintain a high quality in the cast article,`

it is desinable to provide supplementary means for cool-vl hollow'ch'amber 225 formed along each side thereof which` chambers are connected at their lower ends by a lllollow cross-chamber 227. Each side chamber 225 is providedwith a vertically elongated opening 229 eX- tending through the lat face thereof. A metallic plate 231 is iuterlitted betweenthe fiat face lof each

support

214, 215 and the` cooperating inner plate-like members 211,v 213, respectively. Plates 231 are provided with a pair lof vertically elongated openings 233`therein, corresponding and registering-with each of the corresponding openings 229, and each plate 231 is provided with a vertically elongated central opening 235 which as illustrated in Fig. 7 is generally triangular inshape.

The back of inner plate-like members 211, 213 is hollow and'except at the marginal edges is spaced from its co'operating plate 231' so `as to form a passageway 237 between each-opening235and the side openings 233 in each plate 231'. From the construction as |above described, itwill be' apparent that 'there is continuous path of communicar7 tion through the openings 235 in the piates 231, passage- Way 237, side apertures 233 in plates 231, cooperating openings-229 in supports 211, 213 and the cross passages 227 in each

fixture

210, 212. Air or other cooling medium may be forced under pressure through cross passage 227 and out of central opening 235 'or may be drawn in 4the opposite direction through the supports an'd inner plates by subatmospheric pressure. For the purpose of this invention, it is preferred that the air for cooling the inner plate-like members 211, 213 be drawn through the various passages therefor by suction. When suction is employed,

` the suction may be transmitted from each cross passage 227 to its cooperating side chambers 225 Ithrough the eooperating lopenings 229 in each of the supports and the cooperating openings 233 in the corresponding plates 231 to the space 237 between the corresponding plate-like members 211 or 213 and its

support

214 or 215 respectively. The suction thus created within these spaces will cause lair to be drawn through the central aperture 235 in each of the plates 231, through the various passages described `and into the cross passages 227 from which it will be discharged. The air thus flowing through the centual passages 235 in the plates 231 will extract heat from the -members 211, 213 by flowing over the rear faces thereof. The rate of heat extracted from the members 211, 213 is preferably accelerated by providing =a multitude of pins or vertically disposed fins 239 'on the rear faces of the members 211, 213 and projecting into the path of flow of air :over these rear faces.

The air drawn through the assembly shown in Fig. 8

' is vented through the flue or stack 53 and the interconnecting channels between the assembly land the stack will now be described. in the stationary portion 210 of the assembly, the support 214 is provided with a passageway 241 as shown in Fig. 1 which is formed integrally with the cord 27 in communication with the cross passage 227 and extends through and opens the joint 243 between it and the adjacent cord 27. Joint 243 is constructed to receive hollow arm 25 'and is internally provided with a communicating passage between the passageway 241 and the interior of arm 25. As mentioned hereinabove, the interior of arm 25 is in open communication with the interior 'of the central drum member 19 of 'the turret which in turn communicates with the upstanding flue 53.

The air drawn through the movable fixture 212 and over the rear surfaces of inner plate-like member 213 is conducted to the interior of central drum member 19 by means of a tube 247 which extends radially inwardly from the cross passage 227 with which it is in open communication. The inner end of tube 247 projects relatively loosely through an yopening 249 provided therefor at the inner end of'the cooperating arm 25 and in the periphery of the drum member 19, thereby connecting at :all times the cross passage 227 of each movable fixture with the hollow interior of the drum 19. A suitable source of suction may be provided in connection with flue 53 and the suction device may be operated constantly or intermittently during the operation of the turret as desired. As will be noted in connection with Fig. 3, inner plate-

like members

79, 81 are similarly provided with corresponding interconnecting air passages and suction, may be employed, if desired, with any of the shell mold supporting `assemblies of this invention by the use of the means illustrated or `other suitable means which will be apparent to those skilled in the art. Cooling of the inner plate-like members is not necessary for continuous production however, especially where the shell mold is supported and maintained by pins such as in Fig. 9, wherein inner

platelike members

146 and 147 and cooperating

plates

156, 158 are illustrated without communicating air passages.

In conventional permanent mold casting, the cast article sometimes tenaciously adheres to the surface of the permanent mold, `and its removal from the mold face requires the application of considerable force which is customarily applied by hammering or the like. As previously suggested with'the-use of shell molds, sticking of the cast article to the shell mold or to the shell mold supporting fixtures is substantially eliminated and the dislodgement of the cast article from the shell mold supporting fixture is relatively easy. The substantial lack ofsticking is due primarily to the shell mold layer which is interposed between and separates the casting and the supporting fixtures.

One illustrative means suitable for dislodging castings from the shell mold supporting fixtures is shown in Figures l0 and 1l. The shell mold supporting assembly there shown is of the same general type shown in Fig. 8 `and previously described in connection with the molding of heavy articles, and is comprised of a stationary fixture 251 and a movable fixture 253. Each fixture is provided with an inner supporting member 255 which is separated from the inner smooth abutting face of supports 257 by -a centrally apertured plate 259. The rear surfaces of inner members 25S are recessed at 261 and provided with 'a plurality of cooling fins 263 and pins 264. Each fixture is provided with an air cylinder 262 of conventional design having an inwardly projecting piston rod 265 extending through the central apertures 267 of plates 259. Rigidly attached to the inner end of piston rod 265 is a rigidly disposed rod or plate member 269 having a pair ofinwardly projecting knockout pins 271 rigidly secured to its end extremities as by welding or the like. The inner ends 273 of knockout pins 271 are enlarged to present a greater surface area in abutment with the rear surface of each shell mold half 275. Means such as springs 281 for returning knockout pins 271 to their at rest position, as shown in Fig. l0 when piston rod 265 is in its retracted position are interposed between the rear surface 277 of inner plate members 255 and the forward surface 279 of horizontally disposed rod 269. It will be appreciated by those skilled in the art that the number and location of knockout pins 271 will necessarily vary with the shape and size of the article being cast. Air cylinders 263 are supported by suitable bracket members (not shown) positioned beneath the air cylinders and extending upwardly from cords 27 in the case of the stationary fixture 251 and from supporting bracket 140 in the case of movable fixture 253. The method of operation of air cyiinders 263 and the automatic control thereof will be described hereinafter.

As previously mentioned the movable fixture 92 (Fig. 3) is maintained in cooperating relationship with respect to the stationary fixture during that phase of rotation of the turret during which the molten metal is cast into the mold cavity 82, and until a sufcient time has elapsed to insure the molten metal having solidified to such an extent as to make it feasible to open the mold and discharge the part thus cast from between them. The means for effecting this movement is best seen in Figs. 1 and 2. As there shown, a bracket member 310 extends between and is supported on the upper surfaces of each adjacent pair of arms 25 adjacent the central drum 19 and each bracket 310 is provided with an upstanding flange 312 to the rear face of which the forward end of an air cylinder 314 is rigidly secured. The air cylinders 314 are of a conventional type including a piston rod 316 which projects outwardly therefrom through the outer end of the cylinder 314 and flange 312. The cylinders 314 are arranged so that the axis of each piston rod 316 extends centrally with respect to the radial center line of its corresponding assembly. t

The movable fixture 92 of each shell mold supportin assembly has fixed to its inward face as by means of screws 318, a yoke 320 which is provided with a central bore 322 arranged radially with respect to the axis of the rotation of the turrets and in axially aligned relation with respect to the corresponding piston rod 316. The outer end of each piston rod 316 is provided with a peripheral flange 324 adapted to abut against the rear face of the corresponding yoke 320, and a project'mg end portion 326 which projects through the corresponding bore 322 in loosely received relation. `The outerendfportinfdf `the end- 326V is secured in'place by 'means "ofa'xut "32S tire weight of the movable fixture92'is carried ontlie rails 99 without binding of the piston rod `316 `in its cylinder.

VFor the purpose of actuating air cylinders l314,as lwell as lair cylinders '-263 (Fig. 10),"-aconventional valve structure is provided for each cylinder 314 arid when present, the associated cylinders 263. :The control valve structure indicated generally .at 330'is`mo`untedjin adjacent'rrelationshipto the corresponding cylinder 314upon` the'exterior surface of the central'housing member 31. Each valve structure V330 is connected 'bymean's of a pipeline 332 with theforward `end of the'corresponding cylinder 314 and connected vby a'pipeline :336with^ the rear end of its corresponding cylinder 314. Pipeline332 is provided with a T 334 whichisv adapted 'to connect to each of pipelines 33S :and 339 carried by the inward end of air cylinder 263 attached to the movable .fixture i253 and the forward end of air cylinder 263 carried by stationary -fixture 251, respectively. Pipeline 336'is provided with `chargeseintothe interior of the drum 19. The'valves 330 are interiorly in communication with the annular duct'33 in the member 31 so as to receive a'supply of compressed air therefrom. Each valve 33t)` i'sprovided with-'an operating arm 348, the outer end `of which supports `a roller 359 `as best shown in Fig. 2. `It willbe' understood-'that when the arm 348 is at one limit of` its movable'position, compressed air from the duct 33 will be admitted to one end of cylin-ders 314 while air will be permitted to escape from the opposite end thereof through the pipe 346 and when the arm 348 is Iat the opposite limit of its movable position, the reverse of these conditions will prevail. It will be understood that when Iair is :admitted to one end of cylinder 314, that air is concurrently admitted to one end of each of the air cylinders 263 and when the arm 348 is at the opposite limit of its movable position, air will be admitted to the other end of each of the cylinders 263. It will be noted that when Iair is admitted through pipelines 336 to the inward end of cylinders 314 and piston rod 316 is extended radially outwardly closing

fixtures

90 and 92, that -air will be admitted to the ends of air cylinders 263 ladjacent the shell molds so that piston rods I265 will be in .their fully retracted position 4and ejector pins 271 will not extend beyond the inner surface 287 of the inner plate-like members 255. Similarly, it will be noted that when oompressed air from the duct 33 is admitted to the forward end of air cylinder 314 and the movable fixture 92 is separated from stationary fixture 90, that Aair is concurrently admitted into the rearward ends of the air cylinders 263 so that piston rods 265 are simultaneously advanced inwardly relative to the shell mold and the ejector pins 271 are moved through each of the inner plate-like members 255 to thereby eject shell mold halves 275 and/or the solidified casting therefrom.

ln order to effect yan automatic actuation of the movable shell mold supporting fixtures in properly timed relation to the rotatable position of the turret, the following illustrative mechanism is provided. The stationary ring 51 which supports the stack 53 at the center of the turret is provided in its exterior surface with an annular T-slot 347 therein. Secured to the outer face of the ring 51 by means of Vbolts 349, the heads of which are received with the T-slots 347, -is Ia pair of brackets 351 projecting radially outwardly from the ring 51. Each of the brackets 351 has secured to its lower face -a cam ifo bracket F351. The cam members 353 Ias best shown verges in a radially outwardly direction so that upon en- -gagenient with` the4 roller 350 'of4 anyV valve arm 348,the 'valve `arm `will "bef-causedto'nioveto'theoutcr klimit -of` its movable position, andthe jother ca-m' member v353 is arranged with;litsrvsurfaces 359 converging in ian inwardly 'c lirectionso that whenit engages-the rollers `350 ofthe -valve arms *343,"thesearms /willvbe caused lto move-to Athe Ainwardliniit of"theirrrnovable position. By

this meansy as the turret-revolves l'aridfthe-various rollers '35W-successively *f engage firstA oneiof "the Acam members 5353 and lthen'ithe= otherecaim 3531 the "valves willV be oper- *atedfirst "to reffect aclosing vofthe shell mold, supporting 'fixtures aridto'retract piston rods 265, landth'en will be Hoperatedto A'se'paratethe' shell-'mold supporting `fixtures 'and tosimultaneously.advance "pistoni rods 265 to automatically'eje'ct 'the' vsolidified casting and shell mold. The particularpoint atwhich-` "ther'shellf mold supporting fix- -`tures -a1`e )pe'ned4 or closed-maybe readily varied by 30 "simplyshifting the `'brackets 351 'circumferentially' over n'the' particularvalve "structure andcontrol means 'for' actuating the motion of` pistonrods'f3'16'and 265-is illustrative only 'and may Abe varied 5by thoseV skilled in thel artV withoutdepartingfrom the spirit ofthe invention.

1From Atheforegoing,litwill';beapparent that rthere is Lintox/fide'.dian improved "casting machine which `is provided "wit-hilmeansffor supportingarid-maintaining in` position "during-casting expen'dble -shelliniolds' as well' as means for automatically ejecting solidified castings from the shell mold supporting fixtures. It will furthermore be appreciated by those s'killed in the art that there is provided a quantity production machine capable of producing castings which are characterized by the substantial absence of surface roughness and scale, and which require no annealing prior to working of the casting because the shell mold eliminates the contact between the molten metal and a chilled metal surface.

Various modifications and formal changes may be made in the specific embodiments of the invention herein described without departing from the substance of the broad invention.

What is claimed is:

1. A casting machine having a shell mold supporting assembly including in combination a pair of opposed fixtures, one of said pair of fixtures being stationary and the other of said pair cooperating with and movable toward and from the said stationary fixture, each said fixture comprising an outer support and an inner platelike member detachably secured thereto, the front faces of said inner plate-like members being contoured to conform tothe rear surface configuration of a shell mold, and the front face of the inner plate-like member attached to said stationary fixture having apertures therein which serve to support a shell mold positioned between said inner plate-like members, and a shell mold positioned between said inner plate-like members.

2. A casting machine having a shell mold supporting assembly including in combination a pair of opposed fixtures, one of said pair being stationary and the other of said pair cooperating with and movable toward and from said stationary fixture, means for automatically advancing and retracting the movable fixture tov ward and from its cooperating xture, each said fixture comprising an outer support and an inner plate-like member detachably secured thereto,means carried by said inner plate-like member of said stationary iixture for supporting a shell mold, vthe front faces of ksaid inner plate-like members being contoured'fto conform to "the rear surface configuration of a shell mold, and the front face of the inner plate-like memberattached to said stationary fixture having apertures therein which serve to support a shell mold positioned between said inner plate-like members, a shell mold'positioned between said inner plate-like members, and means for cooling said inner plate-like members.

3. A casting machine for casting molten metal having a circular supporting turret, means for rotating the same, a plurality of uniformly spaced shell mold'supporting assemblies adjacent the periphery of the turret and rotatable therewith, each assembly including in combination a pair of shell mold supporting fixtures, one fixture of each pair being stationary and the other fixture being movable toward and from its cooperating stationary iixture, means for automatically advancing and retracting each movable-xture toward and from its cooperating fixture, each said iixture comprising an outer support and an inner plate-like member detachably secured thereto, means carried by the innertplate-like member of each stationary fixture for supporting a shell mold, the front faces of said inner plate-like members being contoured to conform to the rear surface configuration of a shell mold, and the front face of the inner plate-like member attached to each stationary fixture having apertures therein which serve to support a` shell mold positioned between saidv inner plate-like members, a shell mold positioned between said inner plate-like members, and means for cooling said inner plate-like members.

4. A casting machine having a shell mold supporting assembly including in combination a pair of opposed xtures, one of said pair of iixtures being stationary and the other of said pair cooperating with and movabletoward and from said stationary fixture, means for automatically advancing and retracting the movable fixture toward and from its cooperating iixture, each said fixture comprising an outer support and an inner plate-like member detachably secured thereto, means carried by said inner plate-like'member of said stationary iixture for supporting 'a shell mold, the front faces of said inner plate-like members being contoured to conform to the rear surface configuration of a shell mold, and the front Vface of the inner plate-1ike member attached to said sisting of' yieldable pin means mounted on the opposing faces of said stationaryand movable fixtures.

References Cited in the file of this patent UNITED STATES PATENTS 633,872 Mackin Sept. 26, 1899 800,753 Mistelski Oct, 3, 1905 1,453,176 Perrine Apr. 24, 1923 1,499,989 Lehmann July 1, 1924 1,542,643 Pettis June 16, 1925 1,925,497 Shippy Sept. 5, 1933 2,040,165 Baldwin May 12, 1936 2,088,123 Toman July 27, 1937 2,186,019 Hagemeyer Jan. 9, 1940 2,198,497 Hagemeyer Apr. 23, 1940 2,219,864 Dostal Oct. 29, 1940 2,399,824 Pressman May 7, 1946 2,465,019 Johnson Mar. 22, 1949 2,476,374 Hodes et al. July 19, 1949 2,651,822 Davis Sept. 15, 1953 2,660,770 Davis Dec. 1, 1953