US2999281A - Apparatus for making castings - Google Patents

Description

Sept 12, 1961 J. R. DREVER ETAL 2,999,281

APPARATUS FOR MAKING CASTINGS Filed Aug. 14, 1958 5 Sheets-Sheet 1 INVENTORS H famedolu 2rvr 2 55', du/ard WaJ/anuye MM-5W v M71 addonf Sept. l2, 1961 J. R. DREVER ETAL 2,999,281

APPARATUS FOR MAKING CASTINGS Filed Aug. 14, 1958 3 Sheets-Sheet 2 Sept 12, 1961 J. R. DREVERv ErAL 2,999,281 APPARATUS FOR MAKING CASTINGS States APPARATUS FOR MAKING CASTINGS James Ross Drever, Geneva, and Edward C. Kavanaugh and John E. Bossong, 'Oak Park, Ill., assignors to GriflnlWheel Company, Chicago, Ill., a corporation of e aware Filed Aug. 14, 11958, Ser. No. 755,965 2 Claims. (Cl. 22-64) This invention relates to improvements in the art of metal founding and more particularly to a physical arrangement for, as Iwell as a method of operating, a foundry plant.

'Ihe invention comprehends a lay-out of foundry plant facilities and equipment lwherein all of the stations for accomplishing the necessary steps in the production of metal castings are disposed, relative to each other, and interconnected by automatic conveying means, in a manner calculated to alord their continuous operation under conditions of maximum efficiency.

yAlthough the basic concept of assembly line production per se is not new, even to the art of metal founding, yet, the general arrangement of this invention is unlike any arrangement known to exist in the eld of metal founding.

This invention is concerned with a foundry plant for producing metal castings, and particularly railway car wheels, lby a process of pressure pouring molten metal into permanent molds formed of graphite blocks. The invention resides in the arrangement or disposition of, and method for operating, the foundry plant facilities embodied in this invention.

The process of producing steel castings by pressure pouring molten steel into graphite molds entails many problems of production, some of which are common to other types of casting operations and some of which are not.

It is a primary purpose of this invention, therefore, to provide a manner of arranging and operating foundry plant facilities calculated to afford maximum efficiency in production, but utilizing a minimum of time, space, and operating personnel.

rIt is another object of the invention to provide a method ofutilizi'ng'foundry plant facilities requiring a minimum of distance between separate stations for successive casting or processing operations.

A further object of the invention is the provision of a-means for utilizing foundry plant facilities which requires a minimum of manual transporting or handling of equipment. f

A specific object of the invention is the provision of a means of arranging and `operating foundry plant facilities wherein the melting, molding, and cleaning rooms are in longitudinal alignment with each other, with the molding room in the center, and with the pouring station being disposed immediately inteijacent the pouring tube preheating furnaces and the metal melting furnaces.

A more specific object of the invention is the provision of means for arranging and operating foundry plant yfacilities wherein as the separate cope and drag sections of a mold are processed, they travel along enclosed rectilinear paths or routes, one of which is circumjacent the other.

These and other objects of the invention will be apparent from an examination of the following description and drawings, wherein:

FIGURE l is a diagrammatic plan View of a portion of a foundry plant embodying features of the invention, approximately one third of the plant being shown in this View, and

Ala and 1b are views Vsimilar to FIGURE 1, but show other portions of 'the'plant' not *showni'n beread as a single combined gure along the lines X-X and X-Y of the respective gures. Referring now to the drawings for a better understand-1.

ing of the invention, it will be seen that a foundry plant: l

embodying features ofthe invention comprises vthree contiguous sections or divisions: the cleaning room, themolding room, and the melting furnace room, which are illustrated in FIGURES 1, la, and lb respectively. 1;

Although the details of the pouring structure and molds are not shown, as they do not form a part of this in-,. vention, it should be understood that the foundry plant to which this invention pertains is one adapted for pressure casting operations of the type disclosed in copending application Serial No. 236,324, filed July 12, 1951,' now U.S. Patent No. 2,847,739, granted August 19, 1958,; in the name of Edmund Q. Sylvester. In this type of,

casting operation, molten steel is forced by the applig cation of iiuid pressure thereagainst from a ladle, disposed within a pressure tank or container, upwardly against the force of gravity through a ceramic pouring tube mounted within the cover of the container into a bottom ingate of a mold disposed above the container; and comprising cope and drag sections-preferably formed of graphite. The cope sec-tion is provided with separa-k ble 'baked riser liners and also with a stopper assem-; bly operable to close the ingate at the end of each pouring operation. Y

The essential features of this invention reside primarily in the location and arrangement of the three sections or rooms of the foundry plant, relative to each other, and in the locations and arrangement of the processing stations for the separate mold sections andv for the molded castings, relative to each other.

inasmuch as the casting process lbegins with the melting of the scrap metal for the heat, the lay-out of the melting furnace section or room, as seen in FIGURE 1b, will be'lescribed first.

The primary consideration with the location of the melting room and its facilities is that the melting furnaces, preferably two, which are indicated at 10, andv the 'ladle pin 28 are located adjacent and in alignment, longitudinally of the plant, |with the area of pouring or casting, hereinafter referred to as the pouring station, indicated generally at y12. Furnaces V10 are preferably mounted on the ground floor of the foundry so that the furnace doors are accessible from a mezzanine 1\1 and so that the foundation of the furnaces are accessible from the licor 13 itself. A

Although the melting furnace section of the plant includes numerous subdivisions such as the mold repair shop, machine shop, laboratory, and other sub-sections (not shown on the drawings), the other important subsection shown on the drawings is the scrap bin area indicated generally at "1-4, which is disposed on the oppo-Y site side of the melting furnaces from the pouring station and in longitudinal alignment with both the melting furnaces and the pouring station so as to afford accessibility for a pair of traveling bridge cranes 16 and '17 on a common track 19 to all three stations or sub-sections 12, 28, and 14 'of the plant.

Now turning to FIGURE la of the drawing, it will be seen that there is locatedlimmediately adjacent and to the left of the pouring station a tube processing area A18, which includes a tube repairing larea 18a and a tube preheating area 18b. Area 1 8b contains a plurality of furnaces 20 which may be used in preheating the ceramic pouring tubes employed in the pouring operation. The location of the tube'processing area affords accessibility rforV a pair of smaller longitudinally traveling bridge cranes 2,999,281 y Y e as thel tube handling crane, and is used to transfer the pouring tubes from the tube processing and repair areav to and from furnaces Ztl. rvCrane 23, on the right, is known as the pouring crane and is used to transfer the pouring tubes to the --pouring tank i5 in the pouring station l2.. Crane 23 is also provided with a sub-crane or transversely traveling mechanismwhich is operable to transfer molds to and-from the pouring station from conveyors 24 andi26 in a manner hereinafter described.

Disposed adjacent opposite sides of pouring station l2 iarea..pair of aligned reciprocating pusher conveyors eX- tending transversely of the foundry plant. The reciproeating pushing conveyor 24 on the lower side of the drawing -is employed in the pre-pour operation, and the recipro eating pusher conveyor 26 on the upper side of the drawing is employed in the post-pouring operation.

Each reciprocating pushing conveyor (not shown in detail) is of the conventional type comprising a plurality of rollers for supporting the mold sections and a hydraulically actuated reciprocating beam disposed below the rollers and having a plurality of dogs for connection to the mold sections on the rollers. The beam is moved in one direction a predetermined distance, in the case of conveyors 24 and 26 the distance is five feet. 'In operation, this beam moves tive feet, thereby advancing each mold section to which it is connected a'distance of five feet or in other words advances each-mold section one station.

After moving forward ve feet, or one increment, the

position (g) of conveyor 24 or position (n) of conveyor 26, it passes through all of thel intermediate stations on the conveyor before leaving the conveyor unless it is lifted off of the conveyor before it reaches the last station on the conveyor.

ll'nasmuch as the disposition of the facilities and equipment of the molding and cleaning room sections of the foundry plant, like those of the melting room section, are interwoven with their operation, it is believed that the invention can best be described by explaining the various operations of a complete cycle Vin the casting process at the same time, in order to avoid unnecessary repetition.

To return first briefly to the operations of the melting room facilities, it will be understood that the charge is transported from the scrap storage bins 1-'4 to the melting furnaces lill by crane 16.

-T he furnaces 10, preferably two in number, are each preferably of fourteen ton capacity and will supply a heat suticient to pour a minimum of castings of at least 750 pounds each. In this example, the castings to be poured are railway car wheels and the plant is designed to produce a maximum of approximately 240 Wheels per eighthour shift, or in other words, 720 castings per twenty-four hour working day. As the melting time of each furnace is approximately 2 hours and the cycle of operation of the mold processing operation, hereinafter described in detail, is approximately 30 complete molds per hour, by altermating the heats from the two furnaces, it will be seen that each hour one or the other of the furnaces will produce a heat sufficient to form 30 castings or one complete cycle with respect to the processing of complete molds.

To begin the casting oper-ation, a heat is tapped from one of the furnaces to a ladle (not shown) located in pit 28, which is just slightly below ground floor level, and the ladle is transported by crane 17. and lowered into a belowy iloor level pit or pressure 4tank 1S at pouring station 12.

A pouring tube and tank cover assembly (not shown) but disclosed in said Icopending application are then transported by crane 23 to pouring station 12 where the tube and ,cover assembly are lowered onto the tank with the tube disposed to extend down into the lled ladle and with the cover closing the top of the tank around the tube.

'A drag assembly comprising a moid drag section and 16; retainer (not shown, but hereinafter referred to as drag) is transported by conveyor 24 from position (g) thereon to close down position (d) or.(f) thereon, whereat either one of a pair of longitudinally traveling mold closedown cranes pick up a cope assembly comprising a mold cope section and retainer (not shown, but hereinafter referred to as a cope) from position 32 of cope conveyor 34 or position 36 of` cope conveyor '3S and places it on the adjacent drag to close down the mold. The assembled mold is then transported by conveyor 24 to position (a) thereon where it is picked up by crane 23 and placed in position over the pouring tank. After themold is checked and miscellaneous steps, not essential parts of this invention, are completed, the mold is filled and is then transported by pouring crane 23 to position (a) of conveyor 26 as a new mold is placed over pit l5. During pouring of successive molds, the crane 23 remains over the pit 12 with the mold sections being carried by mechanism 25 of crane The complete mold containing the casting (not shown) is then moved by conveyor 26 from position (a) to position (f) thereon. At position (f) the cope is picked up by a longitudinally traveling cope splitting crane 40 and transported to the adjacent end of a. roller flight chain type cope conveyor i2 which moves the cope along to the automatic feed control device or stop 44. Conveyor d2, like the other roller flight chain type conveyors here inafter referred to, is la continuously moving endless power driven chain type conveyor. Stop 44, like the other stops or feed control devices hereinafter referred to, merely comprises a mechanism including arms movable into a position to engage and block further movement of an article traveling along the conveyor, while the conveyor itself continues to move. The stops can be released automatically or manually, as necessary, so as to release one article at a time.

After the cope has been removed and placed on cope conveyor 42,l the drag containing the casting is moved by conveyor 2n to position (g') thereon at which point the casting is picked up from the drag by a transversely traveling hot wheel transfer crane 46 and placed on the end of either one of a pair of chain driven wheel kiln slat type conveyors 48 and 50. Y

After the wheel has been removed, the drag is moved from conveyor 26 by the powered rollers S2, at the end of the conveyor, which rollers 52 move the drag to the powered roller turntable 54 which in turn rotates 90 in a clockwise direction and deposits the drag on the vend of power driven roller chain type conveyor 58.

Turntable 54 (not shown in detail) like all of the other turntables hereinafter described except turntable 235, comprises a base and table rotatable thereon provided with powered rollers which receive an article to be moved, stop moving while the table rotates, and then move the article oil the table to another set of powered rollers which move the article on to the next conveyor. The turntables can be set to operate automatically or by push button so as to move only one article at a time as it is released by a feed control device. ln all cases, feed control devices are located in front of the turntables except in the case of turntable 52 where one is not needed because of the nature of the movement of reciprocating pusher conveyor 26.

In order to describe the remainder of the plant facilities and their operations, the processing routes of the drags, copes, and the castings, respectively, will be discussed in that order.

Conveyor 5S transports the drags along to stop 60, behind which drags on conveyor 58 can accumulate to be released one at a time automatically by feed control device or stop 60 to drag cleaning station 64 where the drag is automatically tipped up at an angle to permit the removal of any foreign material from the upwardly facing drag cavity and to permit cleaning of the drag cavity surface and general inspection of the drag. The

drag is then returned to horizontalV position with the mold cavity facing upwardly;

After the cleaning operation, the drags are moved by roller chain-conveyor 68 to stop 70 where drags can accumulate to be released one at a time. Roller chain conveyor 68 moves each drag to drag spraying station 78 whereat the drag cavity surface is sprayed with a moldpwarsh or coating. g Y g Although the details are not shown, it will be understood that the drag spraying station or booth (as well as at the hereinafter described cope spraying station) may be equipped with automatic means to lift and rotate the drag as the mold Wash is being sprayed on.

After the drag spraying operation is completed, roller chain conveyor 74 moves the drags to stop 80 thereon. As each drag is released by stop 80, it is transported by conveyor 74 to power roller turntable 84 where it is moved onto roller chain conveyor 88 and transported thereby through stop 90 and turntable 94 to roller chain conveyor 98 which moves the drags to stop 100. At this point, one drag at a time can be released and moved onto turntable 104 and from there to position (g) of conveyor 24 and then by conveyor 24 to position (f) thereon, thus ending the cycle of processing for the drag.

After the copes have been picked up by crane 40 from station (f) of conveyor 26 and moved to roller chain conveyor 42, they are moved to stop 44 at which point they can be released one at a time. As each cope is released, it is moved by power roller conveyor 108 to station 110 Where it is tipped up at an angle and the used core and riser liners are removed. The cope is then returned to horizontal position and moved to station 112 where it is again tipped up at an angle and turned to permit cleaning from the other side. After the cleaning operation, each cope is returned to horizontal position and movedout of station 1'12 by conveyor 108 to roller chain conveyor 116 with the mold cavity facing downward. The copes move along conveyor 116 until they encounter stop 118 where they are accumulated and released one at a time for movement onto power turntable 122 where each cope is rotated 90 in a clockwise direction and moved onto power roller conveyor 124. Conveyor 124 moves each cope onto a rotating multiposition core baking table 125 located adjacent the riser liner station 126. Sand may be supplied to the station by an overhead conveyor 128 from sand bins or silos 130 located nearby.

After the sand is put in the riser liners in the copes, the cores or liners are baked as baking table 125 rotates in a counter-clockwise direction. As the table is indexed, one completed cope at a time is ejected from the table and picked up by power roller conveyor 132 and moved to roll over station 134 where the cope is rotated 180 and positioned with mold cavity surface facing upwardly on roller chain conveyor 136. The copes are then moved by the conveyor to stop 138 where one cope at a time is released and moved to turntable 140. At this point, if a cope has cooled to a temperature low enough to permit application of a mold wash, turntable 140 is rotated 90 in a counter-clockwise direction and moves the cope onto conveyor 142 which in turn moves the cope to turntable 146 where the cope is again rotated 90 in a counter-clockwise direction and moved by roller chain conveyor 148 to spray booth or spraying station 150.

If, when the copes reach turntable 140, they are too hot for proper spraying of the mold wash, turntable 140 is not rotated and the copes are moved along a bypass or cooling circuit by power chain conveyor 154 to stop 156 where they are released one at a time and moved to turntable 160, rotated 90 in a counter-clockwise direction, and then moved by power rollers 162 to turntable 164 where they are again rotated 90 in a counterclockwise direction and moved to roller chain conveyor 168. 'Ihe copes can accumulate on conveyor 168 in back of stop 169 and can remain inthe bypass circuit until cool enough to spray, at which time, theycan be" released one at a time and moved to turntable 146, from Where they are moved by conveyor 148 to 'spray booth 150.

At spray booth or station 150, the cope can be lifted androtated while'being sprayed With-'a mold wash solu'- tion'jand then canbe moved to turntable 176 where'it is rotated in a clockwise direction and moved by power rollers .178 to turntable and again rotated 90 in a clockwise direction and moved by conveyor' 182 to a roll-over device 184 where the cope is rotated 90 where the stopper is set. The mold is then rotated 180 where the hair pin hook, which fastens the stopper in position, is attached. Then the mold is rotated 90 to place the mold cavity downwardly again.

At this point, ythe copes are moved by conveyor 186 to turntable 188 where theyrcan be either moved to roller chain conveyor 38 or else can be moved by power rollers 192 vto turntable 194 and then, after being rotated 90 in a counter-clockwise direction, be moved to roller chain conveyor 34. Conveyors 34 and 38 each hold approximately 32 copes, and normally one conveyor is lled before the other. In the case of wheel castings of different weights, one conveyor can be used for one type andthe other conveyor for the other type. Thus, the cope processing cycle is completed and the copes are accumulated on conveyors 34 and 38 in front of stops 198 andV 200, respectively, in position to be released for the beginning of the next cycle.

Thus, it will be seen that there are provided generally parallel cope and drag processing assembly line type routes compactly and eiiciently arranged and disposed in two generally rectilinear closed circuits with the drag circuit being circurnjacent the cope circuit and both paralleling for the most part the adjacent wheelprocessing circuit.

The purpose of enclosure 208 is to preheat new molds. Conveyors 202 and 204 are to convey new and remachined molds through the preheat furnace. Monorail 206 is the means whereby moldsare placed in and removed frorn the process cycle. Y n

FIGURES 1 and la show the processing of the casting, which in this example is Ya steel railway car wheel, after it leaves the pouring station. The wheels are poured at approximately 2,9070" F. and, although they cool to some extent while on conveyor 26, they are still at temperatures of approximately l,500 F. when they are placed on power slat type conveyors 48 or 50 of the wheel kiln 210 by crane 46. Y

The wheel kiln 210, although enclosed to retain some heat therein, is no-t provided with any heating means and its sole purpose is to permit the still hot wheels placed therein to cool gradually from an initial temperature of approximately 1,500 F. down to approximately 900 F. to 1,000 F. As the wheels leave the wheel kiln on either power slat type conveyor 48 or 50 they pass through an intermediate alligator switch 212, the position of which may be altered to receive wheels from either conveyor 48 or conveyor 50, d own to another wheel process line gravity conveyor 214 where they pass through several stations and are subjected to various finishing processes.

The first station each wheel enters as it passes down conveyor Y214 is the s prue removal station 216,where the sprues `are removed from each wheel. Next, each wheel passes through Ia roll-over device 218, after which the residual ceramic stopper is chipped olf at station 220. The wheel progresses to stamping press 222 where it is hot stamped with the necessary markings. Next, the wheel passes to station 224 where one or more hub Vcutting devices are provided to torch cut a bore through the center of the hub. From there, the wheel continues down gravity conveyor 214 to station 226 where the wheel is rolled over so that it is now back in its original position with the lflange down. The wheel then passes raise the wheel to proper elevation to set it into the annealing furnace. The wheels are moved by gravity conveyor 230 to stop 232, as they are released from the stop `232, one at a time, they are -automatically picked up -by a manipulator, indicated generally at 234, and transported to a rotating heat treatment furnace 238. The furnace is provided with a plurality of indexed stops so that each time one wheel is rotated from one position to the next, another 'Wheel is automatically added by the manipulator 234 and another wheel is automatically removed from the furnace vby a second manipulator 236 and placed on gravity conveyor 240.

`The'castings remain in the rotating furnace 238Y for a heat treatment ythat lasts approximately 11/2 hours, which represents the time it takes for one complete revolution of the furnace. The castings enter the furnace at a temperature of approximately 600 F. and leave the furnace at a temperature of approximately 1,600 F.

The wheel is moved by conveyor 240 to a conventional lowerator device 242, the function of 4which is to lower the Wheel from conveyor 240 onto an endless conveyor 244.

As the wheels are moved along conveyor 244, they pass through hub cooling stations 246 and 248 Where the heavier sections or hubs of the wheels are cooled by the application of compressed air thereagainst for a short period and then by the yapplication of a tine spray of water thereagainst for a short period of time. All the time that the wheels are on conveyor 244, the entire surface of each Wheel is, of course, air cooled by the atmosphere surrounding the conveyor which is at room temperature.

As the wheels reach the end of the conveyor, they are moved into a stacking device 250, which automatically stacks the Wheels in piles three high and places them on rollerchain conveyor 252, which trans-ports them to any one of a plurality (preferably 8) of normally disposed chain conveyors 254. The stacks of Wheels are successively positioned on the respective conveyors 254 by a plurality of horizontal pusher mechanisms `256 (only one of which is shown). Each conveyor 254 is adapted to hold stacks of 3 Wheels each or, in other words 60 Wheels. Thus, it Will be seen that ywith 8 conveyors holding 60 wheels each, the wheel storage area, indicated generally at S is capable of holding 480l Wheels or, in other words al1 the wheels cast in two 8 hour shifts. Thus, lby the time the wheels are taken out of the wheel storage they have cooled at least 16 hours and are now cool enough for the iinal processing. After the wheels are moved by conveyors 254 to the conveyor 260, they are moved to a rie-stacker 262 which separates the Wheels from their stacks and passes them into an upender 264 where each wheel is moved to a vertical position and placed onto a downwardly sloping rail 266. lIt rolls down rail 266 to station 268 where it passes through a flange grinding process. The wheels then move along rail 266 to a Wheelabrator 269 Where they are subjected to shot blasting to clean the surfaces of the wheels. From there they move on rail 266 by force of gravity to stations 2'70 and y272 where they are inspected by a magnaglo process and by visual examination. They then continue on rail 266 to a downender at station 274 Where they are returned to a horizontal position again. Any wheels which are found to be defective at this time are removed from the line and taken back to the scrap bins. If the wheels merely need a slight additional grinding, they pass through roller conveyors 278, through turntable 28) to conveyor 282 where they are submitted to further grinding operations and, then pass to turntable 284, where they are upended and placed on a sloping rail 267 and pass to turntable where they are moved while in a vertical position onto rail 266 again and return through the previously described circuit. If the wheels are in proper condition, after reaching turntable 280,

8 they are moved by conveyor 286 to turntable 2883and thence by conveyor 290 to the upender 29.2 which places them in vertical position in order`that they may be introduced to the hub boring machine, indicated generally at 296. At this station, the hubs are bored and the wheels arethen' submitted to a final inspection at station 298 and weighed at sta-tion 3th). The wheels are then ready for transmission to the loading platform 302, preparatory for loading on railway cars (not shown) or track 304.

We claim:

l. 1n an arrangement for continuously producing metal castings by forcing molten metal into permanent molds each comprising cope and drag mold sections and a pouring tube through which the metal is forced under pressure vinto the mold, the combination of: a pouring station for producing the castings; an open conveyor circuit for transporting castings from the pouring station through a plurality of casting processing stations; a closed conveyor circuit for transporting the drag sections from the pouring station through a plurality of drag processing stations and back to the `pouring station; another closed conveyor `circuit: for transporting the cope sections from the pouring station through a plurality of cope processing stations and back to the pouring station; said pouring station being disposed in a `generally straight conveyor line which forms a common part of all three previously 4mentioned circuits; a pouring tube preheat station ad- .jacent the conveyor line and in close proximity to the pouring station; a moldassembly station in said straight conveyor line immediately preceding lthe pouring station; means for transferring preheated tubes to said pouring station; and a mold disassembly station in said straight conveyor line following said pouring station.

2. In an arrangement for continuously producing metal castings by forcing molten metal into permanent molds each comprising cope and drag mold sections and a refractory pouring tube through which the metal is forced under pressure into the mold, the combination of: a pour ing station for producing the castings; an open conveyor circuit for transporting castings from the pouring station through a plurality of casting processing stations, a portionY of said circuit lying in a straight line path; a closed conveyor circuit for transporting the drag sections from the pouring station through a plurality of drag processing stations andv back to the pouring station; another closed conveyor circuit Ifor transporting the cope sections from the pouring station through a plurality of cope processing stations and back to the pouring station; said straight line path forming a common part of all three previously mentioned circuits; a tube preheat station adjacent the straight line path and in close proximity to the pouring station; a mold assembly station in said straight line path immediately preceding the pouring station; means for transferring preheated pouring tubes to said pouring station; and a mold disassembly station in said straight line path following said pouringv station.

References Cited in the tile of this patent UNITED STATES PATENTS j vOTHER REFERENCES Foundry Trade Journal, publication Mar. 16, 1950, vol. 88, page 290 relied on.

Iron Age, publication Apr. 22, 19418, pages 84-'89 relied on.

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