US2722726A - Foundry apparatus - Google Patents

Description

Nov. 8, 1955 R. P. DAVIS FOUNDRY APPARATUS 6 Sheets-Sheet 1 Filed June 26 1951 INVENTOR. Ral h E Davis. BY MM HIS ATTORNEY Nov. 8, 1955 R. P. DAVIS FOUNDRY APPARATUS 6 Sheets-Sheet 2 Filed June 26. 1951 I INVENTOR. Raolz Rfiauz's.

BY 2 z Nov. 8, 1955 R. P. DAVIS 2,722,726

FOUNDRY APPARATUS Filed June 26, 1951 6 Sheets-Sheet 3 INVENTOR. Havlz I? Dal/e19.

HIS HTTOI-ZNE'Y Nov. 8, 1955 R. P. DAVIS FOUNDRY APPARATUS 6 Sheets-Sheet 4 Filed June 26, 1951 I N V EN TOR. Hugo/z 1? Davis. B Y

Nov. 8, 1955 R. P. DAVIS 2,722,726

FOUNDRY APPARATUS Filed June 26, 1951 6 Sheets-Sheet 5 IN V EN TOR.

HaQi/z I. Dave's. BY

HIS A'J'TORIVEY' Nov. 8, 1955 R. P. DAVIS FOUNDRY APPARATUS 6 Sheets-Sheet 6 Filed June 26 1951 52 2% w H m m w 2 i m w f v M w/ Z 6 6 M /E 1 m 2 2 8 0 2 m v/ IL w w m 7 E INVENTOR. Hal 112 PDavcls. BY

H125 ATTORNEY United States Patent O FOUNDRY APPARATUS Ralph P. Davis, Squantum, Mass., assignor, by mesne assignments, to Link-Belt Company, Chicago, 111., a corporation of Illinois Application June 26, 1951, Serial No. 233,640

13 Claims. (Cl. 2264) This invention relates to foundry apparatus and more particularly to metal casting machines for use with shelltype molds.

Molds of the thin walled shell-type are comprised of a major portion of an inorganic molding material such as sand and a minor portion of a component serving to bind the inorganic material. The completed molds are in two or more matching parts having the form of hard thin shells of substantial strength. The inner faces of the matching parts are smooth and finished whereas the outer surfaces are left in a rough and irregular condition. Consequently, during the casting operation using such molds the common weighing methods for ordinary sand molds cannot be used with any degree of success.

The casting machine of the present invention embodies a plurality of casting boxes each adapted to contain a complete mold or molds. As each box reaches a loading position it is filled around the molds with granular refractory material, such as steel shot. Fluid pressure is then applied to flexible liners in the boxes to hold the molds in suitable pouring position while compressing the mold halves together sufliciently to withstand the static pressure of the casting material. Thereafter, the boxes are moved by the machine to pouring position and then to an unloading station for removal of the refractory matcrial. Upon removal of the mold and casting from the casting box it is returned to the initial loading station for another cycle.

The component parts of the casting machine may be summarized as follows:

a. A pair of independently mounted carriers positioned horizontally side-by-side and each carrying a plurality of casting boxes arranged as the rim of a wheel for rotation about the mounting.

b. An overhead hopper mounted between the wheel rims and containing the refractory loading material.

c. A pair of telescopic feed nozzles operatively associated with the hopper for loading one casting box on each carrier simultaneously.

d. Mechanism for opening and closing the hopper outlet and operating the telescopic nozzles.

e. Means for compressing the mold halves together and holding the molds in pouring position.

f. Mechanism for indexing the carriers and casting boxes from the loading stations to the pouring stations to the unloading station.

g. Mechanism for unloading the casting boxes of refractory material and returning this material to the hopper by way of a dust separator and exhaust system.

h. Means for returning the carriers and empty casting boxes to the loading station.

The apparatus so summarized has for an object the expeditious production of all manner of castings from shelltype molds. One or two operators can keep the machine in constant production with a minimum of effort in placing the molds and removing the finished castings after pouring. Relatively unskilled labor may be employed in the production of good quality castings since the opera- 2,722,726 Patented Nov. 8, 1955 tions involved lend themselves readily to minimum skill. The machine itself is of relatively simple nature embodying uncomplicated parts which are durable and rugged as required in general foundry practice.

Other objects and advantages will become apparent from the following description taken in connection with" the accompanying drawings, wherein:

Fig. l is a front elevation partly in section of the casting machine,

Fig. 2 is a top plan view of the machine shown in Fig. 1,

Fig. 3 is a side elevation partly in section of the machine,

Fig. 4 is a front elevation on an enlarged scale of a part of the machine,

Fig. 5 is a section taken on the line V-V of Fig. 4,

Fig. 6 is a schematic view of the fluid mechanism, and

Fig. 7 is a detail view of the pressure chamber 144.

Fig. 8 is a wiring diagram of the electrical connections for the control mechanism.

The carriers Referring more particularly to the drawings, a pair of independently mounted carriers 10 are positioned horizontally side-by-side adjacent the floor line 12 of the foundry. Since each of the carriers is identical with the other, the description of one will suflice for both. Thus, a tubular support 14 extends upwardly above the floor line 12 from a suitable foundation 16 and carries a hollow hub member 18 rotatably mounted on suitable bearings 20. A plurality, in this instance seven, radial arms 22 are secured at their inner ends to the hub portion 18. Underlying the arms 22' and secured thereto by welding or the like is a substantially circular flange 24 carrying a plurality, in this instance seven, driving elements in the form of studs 26 which project toward the floor line 12 but terminate short thereof. The studs 26 are equally spaced around the flange 24 and are respectively positioned intermediate each pair of radial arms 22.

The driving elements formed by the studs 26 are adapted to be selectively engaged by driving means designated generally by the reference numeral 28 (Fig. 2) suitably mounted on a base plate 30 secured to the foundation 16 at the floor line 12. The driving means 28 is preferably power operated and serves to impart rotation to the carrier 10 as desired. To this end, a fluid motor '32 is mounted on a pivot 34 carried by the base plate 30. A reciprocable plunger 36 is operatively associated with the motor 32 for movement substantially perpendicular to the radial arms 22 and carries on its outer end a notched portion 38 suitably formed for operative engagement with an adjacent one of the studs 26. When so engaged, the reciprocable movement of the plunger 36 will serve to impart rotation to the carrier 10 as will be apparent. As viewed in Fig. 2, the right-hand carrier it rotates clockwise while the left-hand carrier 10 rotates counterclockwise. Biasing means in the form of a tension spring 40 is operative between the fluid motor 3.2 and the base plate 33 for maintaining the notched portion 38 in engagement with the adjacent stud 26.

When the reciproeable plunger 36 has completed approximately three-quarters of its travel, a cam 52 acts on a fluid control valve 48 to reduce fluid flow from the fluid motor 32 and thereby reduce the lineal speed of the plunger36 and the rotative speed of the carrier 10. The cam 52 may have a progressive action on the fiuid control valve 48 and thereby cause the rotative speed of the carrier 10 to progressively approach zero as the plunger 36 reaches the limit of its travel.

When the reciprocable plunger 36 has reached the limit of its travel for indexing the carrier 10 one position, it is necessary that it be released from driving engagement .;3 in order that it may return to its initial position while the carrier 10 remains stationary. To this end, a fluid motor 42 is mounted on the base plate 30 and has its reciprocable plunger 44roperable. on.the motor 32 in opposition to the bias of.the.spring 40. A-swivelconnection 46is provided for attaching theplunger 44.t themotor 32.

The fluid motor 42 .is rendered operative forovercomingthe bias-of .theispring 40.by fluid connections to be described hereinafter. The forwardemovement'of the plunger 36 is controlled-by tthefluid control valve 48 mounted 'on -a:bracket.50 carried by .theimotor 32. The fluid control valve 48' is normally biased open and ,is operable to. closed position byzthecam element 52 forming means responsive to movement of the motor plunger 36 to its 'extended position .forioperating thevalve device 48. The cam element'52 is mounted on a guide rod554 carried by. the notched member: 38 "substantially: parallel with the plunger 36. A slotted guide member56 carried by the motor 32 isradapted for :reception of the cam element 52 to -support.:the.-samein operative position relative to the valve device48.

Casting-boxes A plurality, in this instance seven, casting boxes 58 are mounted on each ofthe carriers for rotation therewith. As thecasting boxes 58are identical in construction, the description of one will suflice for all. Eachrbox 58 comprises a generally rectangular casing of cup-shaped form havinga pair of bottom walls 60,spaced one vfIOlTl the other throughout their length .to provide agenerally rectangular outlet. 61 opposite the open end of the box 58. A swivel plate 62 isimovable acrossthe outlet 61 between open and closed positions. A catch member 64 projects from the swivel plate-62 for operating this member between positions. A fluid motor 66 is mounted on the base plate 30 to engage and operate the catch plate 64 at an appropriate location, :such asthe unloading station of this machine. The fluid connections for the motor 66 will be described hereinafter.

The casting boxes 58 are mountedin end-.to-end'relation on the arms 22 of the carrier; 10 .to form the rim of a Wheel. The boxes 58.may"be secured .together in such relation and totheiarms22 by welding-plate 68 interposed between these members. The 'box 58 is of suflicient widthand length to receive the two halves of. a complete mold which is inserted .freely in an edgewise direction through the open end of the box 58. It should be observedthat the width of the box=58 is suflicientto provide a space between .the side Walls thereof andthe mold which is inserted therein for a purpose apparent hereinafter. The mold is supported. on. a1plurality, in this instance four, support bars '70 which extend transversely across the casting box 58 adjacentrthe bottomrwalls 60.

The opposite side walls of the casting box -58.are provided with a pair of liners 72 respectively of generally rectangular form which are secured at their outer edges to the side walls in air tight engagement. The liners 172 are preferably made of flexible sheet material, such as rubber, although any other resilient-or elastic material may be employed. Means for admitting fluid under pressure between the side walls of the boxes 58 .and the liners 72 are provided and take the form of fluid connections 74 mounted on the side walls of theboxes 58 and communicating with the spaces as formed. These fluid connections 74 will be described in detail hereinafter.

In connection with the disclosure of the casting boxes 58 and connections 74, reference may be had to my copending application Serial No. 183,363, filed September 6, 1950, now Patent 2,660,770, issued December 1, 1953, whereinthese devices are fully disclosed and claimed.

"Hopper Positioned between the carriers 101s a pair of supports 76 each of which maybesecuredat one :endtirctherfoundation .16 and having .the. oppositeA-end .projectingtherefrom above the floor line 12. The supports 76 carry an overhead container or hopper 78 therebetween for granular refractory material, such as steel shot. The hopper 78 is generally cylindrical in form, but is provided at one end with oppositely disposed rectangular portions 80 which overlie an adjacent pair of the casting boxes 58 respectively on the carriers 10. Such overlying relationship is established .at anappropriate :location of the carriers 10 and may be termed the loading station of this machine.

Since the rectangular "portions- 80 of. ithe hopper 78 are identical in form description of one will su'ifice for both. .Referring morerparticularly..toJEigs.:41and 5, the rectangular portion 80 terminates in. discharge means for the refractory material whiclr-takes'the form of a W- shaped portion in cross-section. The adjacent lower apices of the W-shaped form are each suitably slotted to provide two pairs ofarectangularsdischalg :orifices .82 which are. spaced one from .the otherrin substantially -.the..sam horizontal plane. The spacing of the orifices 82 is such that material flowing-therefromwill enter thesingleicasting box 58 positionedtherebeneath and on either side of a mold therein oneachof the carriers 10.

A closure meansin the form ofa swinging-.gatermember 84 is provided'for each of the orifices 82 which are positioned in two pairs aszstated. Each gate member..84 is provided with apairofside plates 85=which are pivotedaon the projecting endsofi a rod 87 extending across the rectangular portion 80 and'are movablelin unison to open and close. the orifices- 82 at. appropriate ;times. Such operation of eachtgate member184'is effected by.a toggle bar 86 having itsiopposite ends pivotally mounted on .the side plates 85 atone end of the gatemembers 84.and operable by aplunger 88, of a fiuidwmotor 90. There are two such motors-90 and connectionsfor operating the two pairs-of gates 84 although only one .is shownin Fig. 4 for the purpose of clarity inillustration. Each motor-.90 is supportedyon a bracket 92-carriedby the rectangular portions 78 an-dihaving .suitableguidemeans 94 for.the plunger-.88. As shown inbroken lines on Fig. 4, .reciprocable movement of the plungenSS will serve to operate the toggle-86and move the gate;members 84 between open and closed: positions. The lfiuid connections .for operating-the fluid motors'90. will be described hereinafter.

Feeding means are employed for filling the: casting boxes 58 to a predetermined depthwwith refractory.materiaLfromthe-torifices 82. The feeding means take the form of apair of outlet.membersx96having.a funnelshaped end extending acrossthe orifices: 82v andterminating in relatively narrow nozzle portions-98 adaptednormally to;ov.erlie,a;single :casting:hoxj58 on. either side of the mold positioned. therein. .;A :pair .of. support .bars 100 are secured;to the outlet members 96 at either end of the rectangular; hopper portion 80 and.,are also .secured to the rectangular portionias by the bolts. 1D2rand spacing .collars 104. .:It,may be noted that the support bars 100 on theright-handrside. as viewed :in Fig. 5 are provided with extension: portions for .a purpose. apparent hereinafter.

A plurality,'in:this instance-two, pairs offeeding nozzles 106 of generally rectangular form areadapted for slidable movement relative to the nozzle portions-98 respectively tov form a telescopic .connection therewith. Each pair ofrfeed nozzles-106 is..connected at either end of the rectangulathopper portion 80.by cross-bars 108 which aremountedaonfour rack members 110 respectively and are each cooperable with a pinion 112 -for impartingmovementi thereto. Each pair of pinions112 is securedon the projecting ends of a-rod 114-.extending acrossthe rectangular portion; 80. Thesupport bars 100 alsoserve-to carry a'guideelement 116 for each rack '1'10- opposite the'pinion 112. Ana'dditionalp'air of guide elements; 118-are provided on the support bars 100-for the Iack'110 in suitably spaced relation.

The extension 105 of the support bars 100 carries a bracket 120 upon which is mounted a fluid motor 122 having suitable connection with one of the racks 110 for reciprocating the same and rotating the pinion 112. There are two motors 122 at. one end of the hopper portion 80 for operating the two racks 110 at that end and transmitting movement to the pinions 112 at the opposite end through the rods 114. Alternatively, the telescopic movement of the feed nozzles 106 can be imparted by manual means instead of by the motors 122. Thus, a handle (not shown) can be secured to the projecting end of the rod 114 for rotating the pinion 112 and thus moving the associated rack 110. It will be apparent that the movement of the feed nozzles 106 relative to the portions 98 can be adjusted to any desired amount and the purpose of such adjustment will be apparent hereinafter.

Receiving and pressure chambers Positioned beneath the carriers at the unloading stations on each carrier is a receiving chamber 140 having tapered sides to direct unloaded material to the center portion thereof. The reeciving chamber 140 may be made of sheet material and embedded in the foundation 16 with its upper edge level with the floor line 12. A portion of the foundation 16 both beneath and slightly ofi-set from the receiving chamber 140 may be recessed as at 142 for the reception of a pressure chamber device 144. A flanged head 146 on the pressure chamber device 144 is securely attached to the receiving chamber 140 at the central portion which is suitably apertured to admit unloaded refractory material to the pressure chamber 144.

The pressure chamber device 144 comprises a tubular body member 148 depending from the flanged head 146 and terminating in a conical outlet 150. A discharge pipe 152 is connected to the conical end 150 and extends through the recess 142 to emerge from the foundation 16 at a point remote from the carriers 10. The pipe 152 then extends upwardly from the floor line 12 and is reversely curved to connect with a centrifugal separator element 154 which may be mounted on the hopper 78 for returning the refractory material thereto. A suitable exhaust system 156 may be employed in conjunction with the separator 154 to remove any dust or foreign matter which may be included in the refractory material being returned through the pipe 152 to the hopper 78.

The pressure chamber 144 contains a check valve element 158 which is mounted for swinging movement to open and close the outlet 147 of the receiving chamber 140. Thus, a pivoted arm 160 is shown in Fig. 7 as mounted on a rod 162 supported in the wall of the flange 146 and having an operating lever 164 mounted thereon. The opposite end of the lever 164 is engaged by a plunger 166 of a pressure motor 168 which is mounted on the flange 146. Reciprocation of the plunger 166 by the -motor 168 will impart the desired swinging movement to the valve member 158 through the connections described. The pressure fluid connections for operating the motor 168 will be described hereinafter.

The pressure chamber 144 has a plurality of fluid connections two of which are indicated at 170 in Fig. 3. By application of pressure to the chamber 144 when the valve member 158 is in closed position the refractory material is transported through the pipe 152 and the separator 154 to the hopper 78 and to the point of delivery. The fluid connections for the pressure chamber 144 will be described in detail hereinafter.

During operation of the machine a suitable cover plate 172 is placed across the recess 142 to provide a firm surface for the operating personnel to stand upon.

Operation in the general operation of the machine, it may be assumed that all of the casting boxes 58 are empty and ready for thepositioning of'molds in opposite boxes58 of the two carriers 10. This operation is conducted in the boxes 58 which are positioned immediately in front of the refractory material, loading station. This is the unloading station for both the refractory material and the finished castings. In practice, the refractory material is dumped in a matter of seconds, the castings removed and new molds inserted while at the same time the preceding box 58 is being loaded with refractory material at the loading station. After the loading operation is completed, the carrier 10 is indexed and the dumping of the refractory material and castings and the insertion of new molds is repeated. After several boxes 58 have been loaded in this manner, the pouring operation is commenced with the loaded boxes beyond the hopper 78 which are in positions 1, 2 and 3, for example. By the time these poured molds reach the dumping station, the casting material will be sufiiciently cooled for the unloadin g operation. The cycle may continue indefinitely in accordance with foundry requirements.

With this brief description of the general operation presented, a detailed description of each operation will now be given' Since the operations are duplicated on each carrier the description of one will suffice for both.

Loading operation With the two halves of the mold positioned centrally in a casting box 58 positioned at the refractory material loading station, the nozzle portions 98 of the outlet members 96 will be positioned on either side of the mold and immediately over the casting box 58. The feed nozzles 106 may then be lowered a predetermined amount into the casting box 58 by manual operation of the pinion 112 and rack 110 or by power operation of the motor 122 through manipulation of a multiway valve 174. This adjustment is determined by the operator according to the height of the molds in the casting box, it being apparent that the refractory material should not cover the pouring basins provided in the molds for the casting material. The motor 122 receives pressure fluid from a main line 176, shown in Fig. 6, and having a water separator 178 and filter 180 incorporated therein.

The gates 84 are now moved to the open position by operation of the toggle mechanism 86 by the plunger 88 of the motor 90. The connections for this purpose are shown in Fig. 6 as comprising a multiway valve 184 which can be manipulated to control flow of pressure fluid from the fluid pressure line 176 to the motor 00. As will be observed, two such motors and connections are shown in Fig. 6 for operating the gates 84.

With the gates 84 in open position, refractory material will flow from the hopper 78 through the nozzle portions 98 and the lowered feeding nozzles 106 into the casting boxes 58. Such flow automatically ceases when the loaded material is approximately level with the outlet ends of the feeding nozzles 106 within the casting boxes 58. The multiway valve 184 is then manually operated to reverse the stroke of the plunger 88 of the fluid motor 90 and close the gates 84 controlled thereby.

An important feature of this invention now comes into operation. It will be apparent that while the flow of material from the hopper 78 is cut-off by operation of the gates 84, that both the feed nozzles 106 and the discharge ends 98 of the adapters 96 are at such times filled with refractory material. The feed nozzles 106 are now retracted either manually by operation of the pinion 112 and rack or by the motor 122 due to operation of the multiway valve 174. The nozzles 106 will thus assume their initial positions relative to the discharge ends 98. During this retracting operation, the refractory material which Was contained in these members will flow therefrom into the casting boxes 58 bringing the material to the desired level which has been predetermined by the depth to which the feeding nozzle 106 were lowered into the casting boxes 58. i

After the casting boxes 58 have been filled in this +7 mannergfiuid pressure is-admitted through the connections 74 to the-space between the-liners 72 and the wall of the casting boxes 58. Suchfl uid'pressure is admitted on-ea'ch sideof the mold within the casting box78' and thereby*compresses such-mold sufliciently to Withstand the static'pressure of the casting metal. As shown in Fig. 6,-a-separate conduit 224 is provided for supplying each of the connections 74 and the conduits 224'may be controlled individuallyby shut-off valves 226. The conduits 224'extend from the-casting boxes to a rotatable pressure joint 228 which'surmounts the hub member 18#and-is'provided with a supply conduit'229 extending through the supportf14'having a reducing valve 230 and indicator 232 interposed therein. HBy operation of the reducing valve 230; the fluid pressure in the casting boxes 58 :may :be:set .to approximate orexceed the static pressureof the casting material in the mold as "Will be understood.

Pouring operation 'The.casting boxes 58 which have now been loaded may be indexed through the unloading station to one of the pouringpositions .as previously described.

Thus, by manipulation of a multiway valve233, fluid pressure is admitted toathezrnotor 42 so that the plunger 44 operates the-swivelconection 46 to rotate the fluid motor 32about its pivot 34 against the bias of the spring 40. ",Hence, the notched portion 38 is moved out of operativeengagement with the related stud 26. It should be-observed that the fluidpressure from multiway valve 233- does not act on fluid motor 32 until such pressure has. become sufficiently high to overcome a suitable sequence valve 235. The valve 235 is provided for .the purpose of permitting motor 42 to act before pressure-is admitted tothe fluid motor 32 for freeing the notched portion 38 'from the stud 26 as described.

The multiway valve .233 is preferably of the neutral position type so that all its portsare open. Thus, when the neutral position is reached, the fluid pressure in motor 42-drops to zero and; plunger 44 is returned to its initial or starting position under the bias of the spring 40. Since'the 'fluid motor 32 is also under the bias of the spring 40, a swinging motion in reverse occurs about its pivot 34 causing the notched portion 38 to engage the next stud 26 in line. Now, by manually reversing the multiwayvalve. (233,Ifluid pressure isnadmitted to the motor'32 fonadvancing the plunger 36 .and notched portion '38 thereby indexing the carrier as soon as the engagement occurs betweenthe stud 26 and notched.portion 38.

A suitable conveyor (not shown) may be employed for handling the casting material from the point of .melting to the pouring position. After the pouring operation, the carriers'10 are indexed to the unloading station as previously describedwhich is immediatelyinfront of the loading-station. Prior 'to unloading, the fluid pressure within the casting boxes .is exhausted by operation ofthe shut-off valve .226 tofree the refractory material for, the unloading operation.

Unloading operation The unloading operationis conducted by opening the bottom wall 62 of 'the' casting'boxes and permitting the refractory material to drop by gravity into the receiving chamber.140. Thus, in theunloading position the catch 64.for operatingthe bottom walls 62 is in position to be engaged by the pressure motor 66 which is under the controlof ,a :multiway valve. 234 connected in the pressure system of :the line 176. Suitable manual manipulation of ithe .valve3234-will .thusnoperate the ibottom'wall 62 to empty the' casting box 58.at.the.unloading'station.

,Lhe refractoryrmaterial :drops into .the. receiving. chamber. 140..and thecheck valve 158 is operated .toradmitt this material .to .the- PICSSHICTChHmbCI" 144. Such .operation need only bezconductedavhen-zthe .receivingmhamber 140 is;suificiently filled with: refractory material. .Theffluid motor l68 controlling the' check valve 158 F isconnected, as shownsin Fig. 6; to the fluidmressure line 176-through amultiwaytsolenoid' operatedvalve 185. The connections to opposite endsofithe' 'fluid m'otor' l68' from thevalve' 185 embodyasuitable'type of sequence valve 218 in'the connection for opening the =check-valve" 158 "anda reverse action pressure switch 222 in*the connection for closing the valve 158. The: pressure switch 222is adapted toclose abapproximately p. s. i.'-fluid pressure and to open-at approximately 40p. 5. i. fluid pressure.

As previously "stated, the fluid: connections for-the'pressure chamber l44iin'clude:eonnections170'leading to the chamber 144. These connections aresupplied jointly from the conduit 1229 by an auxiliary conduit 231 which includes: a solenoid: operatedshut-off valve-252 controlling the" flow :of r pressure fluidrtherethrough. i The pressure chamber also has a suitable pressure switch 190 connected thereto and adapted to close ahapproximately 20 p. s. i. fluid pressure and open-at.approximatelyv40ipws. i..fluid pressure. This switch.190. is hence .of .the. regular'action type. as .distinguished from the reverseractionwof the switch 222.

Referring to the'wiringdiagramFig-8, the.circuit.for the solenoid valve may betraced. fromline-wireLl, wires =186,.188,.pressure. switch 190, .wire 192; signallamp 194, .wire .196,primary.of...transformer 198,: and wire .200 td-line wire.L2. Thesecondary of the transformer 198, now energized, has, oneJterminal connected by-wire 202 to groundand the opposite terminal thereof connected by wire 204 toone terminal of =a.|micro.-switch 206. The switch 206 is of the double-throw type having an-opposite terminal connected by wire 208 to one terminal of the solenoid valve 185, .the opposite terminal of whichis connected by wire' 210, to another terminal of the switch 206. The solenoid'valve'185 hasa- pair ofcoils 212 and 214 for advance .and. retract operations respectively and .is provided-witha. center..tap-216 to. ground.

Since thezswitchris deerned .to be closed and the micro-switchi206ais in-position for...closing.the circuit to the advance solenoid 212,.thenfluid pressureis admitted to the end of the pressure motor. 168 .controlledby the sequence. valve218.fOrDpeningthecheck valve 158 controlling the'.flow of refractory .material to the chamber 144. When the pressure chamber. 144 is filled with refractory materialthe. check valve. 1-58is operated to closed position.by.manual.operation of-a pushzbutton 220 operably associated with the micro-switch 206. Such op eration serves to operate the micro-switch 206 to open the circuit of the advance solenoid coil 2'12 previously traced and to close. a circuit for the retract solenoid coil 214 by'way of wire1210. "Pressurelfluid is now. admitted by operation of the solenoid valve.185 to.the opposite end of theifluid motor 168"for. closing .the check valve 158. The pressure "chamber' l44 is now'filled with refractory material and is pressuretight.

'The chamber 144' is emptied by admitting fluid under pressurethrough the connections'170 as described. It is apparent that as 'the'fluid pressure to 'the motor 168 for closing 'thefcheck valve.I58 reaches 75 p. s. i., oras the systempressure in supplyline' 176 may be 75 p. s. i. or more,lthen. pressure switch222 becomes closed due to its reverse actionand establishes a circuit for the solenoid valve 252 as follows: 'Line wire. L1, wire 186, pressure switch 222, wire22'50, coil 251 of solenoid valve.252, wire 254..a.nd. wire' 200 .to'line wireLZ. The opening of .the solenoid valvef2'52 admits'fluid underpressurefromthe conduit 229 to the pressure chamber 144 and the refractory material is .transportedback to the hopper '78 as described. The pressure in the 'chamber144 reaches that for which "the pressure switch 190 .is. set (40 p...s. .i.)..in a matter-of second arid this switch 190 will consequently be moved to operr'position. Such operation will open the .circuit of the primaryef. transformer 198-:and deenergize .thenretract: solenoidrcoiL214z while extinguishing thersignalljght .194. The;operator:1nay;now:releue 9 the push button 220 and cause the switch 206 to reestablish the secondary circuit through coil 212 of the solenoid valve 185.

Upon the chamber 144 becoming emptied of refractory material, the fluid pressure therein is substantially instantly reduced to zero and the pressure switch 190 thereby closes. The circuit through the primary of transformer 198 is reestablished and since the secondary circuit was previously closed the coil 212 becomes energized. The position of the solenoid valve 185 is thus reversed. However, the fluid pressure afifecting the pressure switch 222 soon drops to zero as this pressure overrides the sequence valve 218 and acts to reverse the fluid motor 168. It should be observed that the sequence valve 218 serves to delay opening of the check valve 158 to permit the pressure switch 222 to shut off fluid pressure to the pressure chamber 144. The check valve 158 then opens, the signal lamp is illuminated, and the system is in condition for another cycle.

It will be apparent that many changes may be made in details of construction and arrangement of parts and that certain phases of the cycle may be rearranged or omitted without departure from the scope of the invention as defined in the appended claims.

I claim:

'1. In a casting machine, the combination of a carrier having support means movable through a predetermined path, separate loading and unloading stations adjacent said carrier, a plurality of casting boxes, means for mounting said boxes on said support means for movement there with along said path and through said stations, means in each of said boxes for supporting a completed mold therein and positioning the same to define a space between the mold and at least one side of said box, a container for granular refractory material having discharge means at said loading station for loading said material into said space to support the completed mold, and means operable at said unloading station for emptying said boxes of said material.

2. In a casting machine as claimed claim 1 the combination of means operable for returning said material to said container.

3. In a casting machine, the combination of a carrier, a loading station adjacent said carrier, a plurality of casting boxes mounted on said carrier for movement in sequence through said station, means in each of said boxes for supporting a completed mold therein and positioning the same to define a space between the mold and at least one side of said box, a container for flowable granular refractory material having a discharge outlet at said loading station, feeding means communicating with said outlet and being movable into said boxes to a predetermined depth adjacent the molds supported therein, means for controlling passage of said material from said outlet into said space for loading therein an amount set by said feeding means, and means for withdrawing said feeding means upon completion of said loading operation.

4. In a casting machine as claimed in claim 3 the combination of a separate unloading station adjacent said carrier, means operable at said unloading station for emptying said boxes of said material, and means operable for returning said material to said container.

5. In a casting machine, the combination of a rotary carrier having radial arms thereon, separate loading and unloading stations adjacent said carrier, a plurality of casting boxes mounted on said arms in end-to-end relation forming a fixed rim portion of a wheel, said boxes being adapted to be retained on said carrier for movement in sequence through said stations, means in each of said boxes for supporting a completed mold therein and positioning the same to define a space between the mold and at least one side of said box, a container for granular refractory material having discharge means registering with said boxes at said loading station for loading said material into said spaces to support the completed molds,

10 means for controlling passage of said material from said container to said space, and means operable at said unloading station for emptying said boxes of said material. 6. In a casting machine, the combination of a rotary carrier having radial arms thereon, separate loading and unloading stations adjacent said carrier, a plurality of casting boxes mounted on said arms in end-to-end relation forming a fixed rim portion of a wheel, said boxes being adapted to be retained on said carrier for movement in sequence through said stations, means in each of said boxes for supporting a completed mold therein and positioning the same to define a space between the mold and at least one side of said box, a container for granular refractory material having discharge means movable relatively to said boxes at said loading station for loading said material into said spaces to support the completed molds, closure means movable between open and closed positions for controlling passage of said material from said 'discharge means to said spaces, means carried by said container for moving said closure means between said positions, means for compressing said material in said boxes around the molds, and means operable at said unloading station for emptying said boxes of said material.

7. In a casting machine, the combination of a rotary carrier having radial arms thereon, separate loading and unloading stations adjacent said carrier, a plurality of casting boxes mounted on said arms in end-to-end relation forming the rim portion of a wheel, said boxes being adapted to be retained on said carrier for movement in sequence throughsaid stations, means in each of said boxes for supporting a completed mold therein and positioning the same to define a space between the mold and at least one side of said box, a container for granular refractory material having a discharge outlet at said loading sta-' tion, feeding means communicating with said outlet and being movable into said spaces respectively to a predetermined depth, closure means movable between open and closed positions for controlling passage of said material from said discharge outlet to said spaces for loading therein an amount set by said feeding means, means carried by said container for moving said closure means between said positions, means for withdrawing said feeding means upon completion of said loading operation, means for compressing said material in said'boxes around molds sup- I ported therein, and means operable at said unloading station for emptying said boxes of said material.

8. In a casting machine as claimed in claim 7 the combination of means operable for returning said material to said container.

9. In a casting machine, the combination of a carrier, a loading station adjacent said carrier, a plurality of casting boxes mounted on said carrier for movement in sequence through said station, means in each of said boxes for supporting a completed mold therein and positioning the same to define a space between the mold and at least one side of said box, power means movable into operative engagement with said carrier for indexing said boxes through said loading station, a container for flowable granular refractory material having a discharge outlet at said loading station, feeding means communicating with said outlet and being movable into said spaces in said boxes adjacent the molds supported therein, manually operable means for adjusting said feeding means to a predetermined depth in said boxes, closure means movable between open and closed positions for controlling passage of said material from said outlet into said spaces for loading therein an amount set by said feeding means, said manually operable means being operable for with drawing said feeding means upon completion of said loading operation.

10. In a casting machine, the combination of a conveyer having support means movable through a predetermined path, separate loading and unloading stations adjacent said conveyer, a plurality of casting boxes, means awaaprae in each of sa'id boxes --for supporting a completed mold therein 'and positioningthe same -to"define a space'between the' mold and at l'east one side:of said box, means for mounting \saidboxes on said support means =for movementrtherewith along said path and :through said stations, a container fon'granular refractory' material having discharge means-at said loading stationfor loading said matenialintousaid' spaces to support "the completedmolds in said" boxes, means responsivevto the level of said rnaterial in said boxes for terminating flow 'of said material through said dischargemeansnwhen-said.material in said boxes reachesnapredetermined :level landnmeans operable at said unloading station for ernptying saicl boxes of said material.

'1 l 1. In-a: casting machine, the combination ofta casting box,lmeansvin :said box .for :supportinga completedrmold thereinmandtpositioning:the same'itoidefine a space hetween the;rnolduandnatleastone side of saidlbox, a container: for z'flowablegranularrefractory material, means including. a hollow: element: defining a passage communicating -with said spacei'and the interior of said :container, said element'beingzmovable into saidi space to a predetermined depth adjacentsa.mold supportdfin :said box, and gate means for controlling the flow of said material in said :passage.

12. In a casting machinegtthe combination of :an open ended casting box,means 'inwsaidbox "for supporting a completedmold .along a2central verticaliplane thereof and spaced from .the" sides 'thereoflua .container for flowablehgranular refractoryimaterial, meansiincluding a pair of spaced hollowielements defininga pairof passages communicating with the interiorsof said TbOX and said container, said elements being movable 'into said box to a pretermined depth and adapted to straddle a-mold'supported therein, 'and'gate means for vcontrolling the flow of said materialrin said :passages.

13 ln fouiicling sapparatus: for casting; the combination ofi axoonveyenmovable through: a predetermined pathpseparate loading and unloading stations, a plurality of openended :oontainers 'on said :conveyer and :arranged itot be movedzstherebyrialong rs'aid apathi and. through said stations, gate means: operableiforclosing the bottom ends of said containersgvmeans associatedtwitheacnof said containers fonsupp'orting axcompletely formed moldtherein and positioningrthel'sameito defineza space-between the 'rnold and atirl'east one: sidexof said'acontainer, meanssat said loading station 'ifor zloaIding=igranular lrefractory material sinto said spacei'in eachtof:saidrcontainersIto support 'the' 'mold disposed therein, andmeansifor operating said :gate1means tonopenxthetbottom ends 'ofzsaidlcontainersiat said.unloading: station rand crlischarge' said' 'maten'al therefrom.

R'eferen'ces' Cited in the file 'of'this'patent UNITED STATEQFATENTS 329,814 Carr Nov. 3,1885 382,217 (Davies May l, 1888 53 5415 Walstrom :Feb. 19, 1895 572,278 Ryan Dec. 1, 1896 776,696 Sherman Dec. 6,n'-l904 8 19 ,883 Hewlett et.al. May 8, 1906 1,011,735 Brown Dec. 12, 19.11 1,015,374 Yeager Jan. 23, 19.12 1,556,980 V-iaI Oct. 13, 1925 2,049,967 sLuton Aug.'4, 1936 2,549,790 :Finkeldey etal. 'Apr. 24, 1951 2,660,770 --Davis Dec. 1, 1953 FOREIGN PATENTS 488,283 iGer-many Aug. 7, 1907

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