US3825057A

US3825057A - Horizontal centrifugal casting machine

Info

Publication number: US3825057A
Application number: US00277920A
Authority: US
Inventors: F Baumann; B Kaczkowski; G Rosenberry; W Smith
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1972-08-04
Filing date: 1972-08-04
Publication date: 1974-07-23
Anticipated expiration: 1991-07-23
Also published as: JPS5216847B2; FR2194507A1; DE2320435C3; DE2320435B2; JPS4979924A; IT998294B; DE2320435A1; ES417564A1; SU539509A3; GB1437435A

Abstract

A horizontal centrifugal casting machine is described wherein a sectionalized mold for casting a cylindrical structure, e.g., a finned motor frame, is assembled, the structure cast and the mold sections stripped from the cast structure in an entirely automated process. The casting machine includes a plurality of arcuately shaped mold sections mounted upon jaws capable of being secured to pistons of pulling cylinders. With the pistons extended, the mold sections form a substantially cylindrical structure and dual annular rings having a tapered radially inner face are traversed axially along a tapered outer portion of the jaws to fixedly secure the mold sections in position. After disengagement of the pistons, the mold is rotated by a high speed drive motor whereafter a ladle containing molten metal is inserted axially within the mold and the ladle is tilted to pour the molten metal into the mold. The ladle then is withdrawn and a mandrel assembly supporting the ladle, an expandable arbor and a mold coating device is rotated to register the expandable arbor with the mold. The high speed drive motor then is de-energized and the mold stopped at a predetermined angular position using a low speed drive motor. After the expandable arbor is inserted axially within the mold and the arbor expanded to engage the interior of the cast cylindrical structure, the pistons of the pulling cylinders are driven radially inward to engage the outer surface of the jaws and the annular rings are released to permit the pistons to strip the mold from the cast structure. The cast then is removed from the interior of the stripped sections and the open jaws are coated with casting lubricant permitting the casting cycle to be repeated. To obtain optimum quality in casting finned aluminum motor frames, the rate of rotation of the ladle during the pour should vary to effect a more rapid rate of angular displacement at the initiation and termination of pouring metal from the ladle than at the middle of the pour to produce a constant flow of metal from the ladle.

Description

United States Patent [191 Baumann et al.

[ July 23, 1974 1 HORIZONTAL CENTRIFUGAL CASTING MACHINE [75] Inventors: Frederick William Baumann, Scotia',

Bernard Ceasar Kaczkowski, Schenectady; George Mowry Rosenberry, Jr., Elnora; William R. Smith, Ballston, all of NY.

[73] Assignee: General Electric Company,

Schenectady, NY.

[22] Filed: Aug. 4, 1972 [2]] Appl. No.: 277,920

FOREIGN PATENTS OR APPLICATIONS 488,074 12/1953 Italy 425/435 Primary Examiner-J. Spencer Overholser Assistant Examiner-John E. Roethel Attorney, Agent, or Firm-Vale P. Myles [57] ABSTRACT A horizontal centrifugal casting machine is described wherein a sectionalized mold for casting a cylindrical structure, e. g., a finned motor frame, is assembled, the

structure cast and the mold sections stripped from the cast structure in an entirely automated process. The casting machine includes a plurality of arcuately shaped mold sections mounted upon jaws capable of being secured to pistons of pulling cylinders. With the pistons extended, the mold sections form a substantially cylindrical structure and dual annular rings having a tapered radially inner face are traversed axially along a tapered outer portion of the jaws to fixedly secure the mold sections in position. After disengagement of the pistons, the mold is rotated by a high speed drive motor whereafter a ladle containing molten metal is inserted axially within the mold and the ladle is tilted to pour the molten metal into the mold. The ladle then is withdrawn and a mandrel assembly supporting the ladle, an expandable arbor and a mold coating device is rotated to register the expandable arbor with the mold. The high speed drive motor then is de-energized and the mold stopped at a predetermined angular position using a low speed drive motor. After the expandable arbor is inserted axially within the mold and the arbor expanded to engage the interior of the cast cylindrical structure, the pistons of the pulling cylinders are driven radially inward to engage the outer surface of the jaws and the annular rings are released to permit the pistons to strip the mold from the cast structure. The cast then is removed from the interior of the stripped sections and the open jaws are coated with casting lubricant permitting the casting cycle to be repeated. To obtain optimum quality in casting finned aluminum motor frames, the rate of rotation of the ladle during the pour should vary to effect a more rapid rate of angular displacement at the initiation and termination of pouring metal from the ladle than at the middle of the pour to produce a constant flow of metal from the ladle.

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am 0? ar 15 RHYDRAULIC so u RCE iIZQ POUR CYCLE Pmzmmmzawu 3.825.057

SHEET 11 N 15 PATENTEDJIIL23|974 3.825.057

saw 12 or 15 FILL LADLE WITH REQUIRED QUANTITY OF MOLTEN METAL DRIVE MOLD SECTIONS INTO CYLINDRICAL CONFIGURATION DRAW LOCK RINGS AXIALLY INWARD TO LOCK SECTIONS IN POSITION DISENGAGE AND WITHDRAW PULLING PISTONS FROM MOLD SECTIONS ROTATE MOLD AND CIRCULATE COOLANT INTO MOLD INSERT LADLE INTO MOLD AND POUR STOP MAIN MOLD DRIVE AND INDEX MOLD WITH PULLING PISTONS WITHDRAW LADLE AND ROTATE MANDREL ASSEMBLY TO INDEX THE ARBOR WITH MOLD INSERT ARBOR WITHIN MOLD AND EXPAND ENGAGE PULLING PISTONS WITH MOLD SECTIONS AND STRIP FROM CAST REMOVE CAST FROM INTERIOR OF MOLD SECTIONS AND INDEX SPRAY HEAD WITH SECTIONS SPRAY STRIPPED MOLD SECTIONS WHILE DRIVING SPRAY HEAD THEREIN RETRACT SPRAY HEAD AND INDEX LADLE WITH MOLD I withdraw the cast pipe from the mold.

HORIZONTAL CENTRIFUGAL cssnnc MACHINE This invention relates toa horizontal centrifugal casting-machine for casting finned cylindrical structures and inparticular, to a casting machine wherein a sectionalized mold is assembled into a cylindrical configuration; the structure is centrifugally, cast within the mold and the mold stripped from the structure in a sub stantially automated process.

In the manufacture of dynamoelectric machines, "a number of diverse techniques heretofore have been proposed and/or utilized to fabricate machine frames dependent upon such diverse factors asthe size and number of frames to be cast. For example, high pressured die casting techniques have been employed to produce cylindrical frames below approximately inches indiameter on a high volume basis while machine frames above lO inches in diameter generally have been formedcommercially by sand casting or extrusion techniques.

While centrifugal casting has been known for many years, centrifugalcasting machines primarily have been limited to casting structures having a'smooth outer surface, such as metal pipes, or for applying interior linings to preformed objects, e.g., casting brake linings along the interior of brake drums. Foreitample, a centrifugal casting machine is described'in U.S. Pat. No.

1,917,872 for casting brake drum linings'by inserting a ladleinto a metal drum retained in position within a plurality of arcuately shaped segments and gradually tilting the ladle topour metal at'a uniform rate into the drum. Because the mold is separate from the centrifugal casting machine and forms a part of the finished product, there is no need to strip the mold from the centrifugally cast metal. A highly automated centrifugal casting machine for producing. smooth surfaced pipes also is shown-in U.S. Pat. No. 3,457,986 wherein a plurality of molds are mounted along the periphery of a rotatable turret and the turret is revolved to register the individual moldswith circularly disposed stations, i.e., a centrifugal casting station, a spray cooling stahowever, is Ispecifically designed for smooth surfaced objects and would not be suitable for casting finned structures because of theuse of expandable tongs to It also has been proposed (i.e., in Baumann et al U.S. Pat. applications, Ser. No. 220,285 entitled Horizontal Centrifugal Casting Machine" and Ser. No. 220,286 entitled "A Dismemberable Mold For Centrifugally Casting Pinned-Structures," both filed Jan. 24, 1972, now U.S. Pat. No. 3,744,707, and both having the same assignee as this application), that a sectionalized mold be seated upon horizontal rollers of a centrifugal casting machine to permit substantially automated casting of finned cylindrical structures. Because the mold is not fixedly secured to the casting machine, the mold can be lifted from the rollers by a crane and transported to a stripping machine (such as is described in LaBahn et al U.S. Patent application, Ser. No. 220,280, entitled Method and Apparatus For Automatically Stripping A Sectionalized Mold From A Cast" and Baumann et al U.S. Patent application, Ser. No. 220,279 entitled "Automated Method Of Manufacturing Finned Machine Frames," now U.S. Pat. No. 3,741,278, both filed tion, apipe'withdtawal station, etc., to effect the se quential steps. of the casting process. Such machine,

Jan. 24, 1972 and having the same assignee as this application) to strip the sectionalized mold from the underlying centrifugally cast structure. While the centrifugal casting equipment and casting methods disclosed in the foregoing applications are highly'suitable for casting large diameter finned cylindrical structures, the production rate is somewhat limited by the necessity for transferring the mold from the casting machine to the stripping machine. Moreover, because the crane required to transfer the mold from the casting machine to the stripping machine normally is under the control of an operator and because the heat of the mold makes manual assistance in the transfer difficult, substantial labor is required to complete the process notwithstanding the automated nature of each individual machine utilized for casting.

It is therefore an object of this invention to provide a highly automated centrifugal casting machine wherein the mold is assembled, the structure cast and the mold stripped from the cast in a single machine.

It is also an object of this invention to provide a centrifugal casting machine capable of producing a. large quantity of cast finned structures on a substantially automated basis. i It is a further object of this invention to provide a centrifugal casting machine having a mold locking assembly capable of securely fastening the individual mold sections into a composite unit for casting while permitting ready disengagement from the mold for stripping the mold sections from the cast structure.

It is a further object of this invention to provide an automated method-of casting finned cylindrical structures and stripping'the mold :from the cast structures.

A horizontal centrifugal casting machine for casting cylindrical structures in accordance with this invention generally includes a plurality of arcuate mold sections having interlocking edges and means connected to'the mold sections for moving the sections into juxtaposition to form a cylindrical mold capable of confining the liquid material to be cast. Means also are provided for connecting a rotary driveto the cylindrical mold for rosections from the cast and to prevent fracturing of the cast structure during stripping, the casting machine preferably also includes means for inserting an arbor within the cast cylindrical structure and means for expanding at least a portion of the arbor in a radial direction to contact the interior of the cast structure prior to stripping the mold sections from the cast. When the molten-material is poured into the rotating mold from a ladle, suitable means desirably are included within the machine to tilt the ladle at a variable rate during the pour, Le, a more rapid angular displacement of the ladle is desirable at the beginning and end of the pour than at the middle of the pour, in order to produce constant flow of metal from the ladle and high quality in the finished cast product.

Although this invention is described particularity in the appended claims, a more complete understanding FIG. 3 is a view of the apertur'ed plate utilized in the speed sensing and mold positioning assembly,

FIG. 4 is an enlarged sectional ,view of the speed sensing and mold positioning assembly,

FIG. 5 is a sectional view taken along lines 55 of FIG. 1 to illustrate the 'I -s'haped groove wherein the gripping jaws slide,

FIG. 6 is an enlarged view of the lock rings utilized to secure the mold in position for casting,

FIG. 7 is an isometric view of the mold in a machine mounted assembly,

FIG. 8 is a view depicting the serial connection of the coolant hoses to the mold sections,

FIG. 9 is a sectional view of'themold pulling assembly,

FIG; 10 is a sectional view of the ladle: rotation mechanism,

FIG. 11 is a view of the variable the ladle rotation mechanism.

FIG. 12 is a graph illustrating the variation of rate of angular displacement of the ladle with the quantity of aluminum poured from the ladle, V g

FIG. 13 is a sectional view of the expandable arbor,

FIG. 14 is a view of the I4-14 of FIG. 13,

FIG. 15 is a sectional view of the lubricantspray mechanism of the casting machine, a

FIG. l6is an' elevation view of the main turntable,

FIG. 17 is aplanview of the main turntable to illustrate the speed control and positioning mechanism of the turntable FIG. 18 is a view of the'main turntable rotary drive,

FIG. 19 is a sectional view of the mechanical registration piston of the main turntable,

FIG. 20 is a sectional view taken along lines 20-20 of FIG. 17 toillustrate the limit switches controlling table rotation,

FIG, 21 is aflow chart showing the sequential operation of the casting-machine, and

FIG. 22 (a-c) is an electrical diagram of a circuit suitable for controlling the operation of the machine.

A horizontal centrifugal casting machine 10 in accordance with this invention is shown in FIG. 1 and generally comprises a drive and transmission unit 11, a mold assembly and stripping unit 12 and a mandrel assembly 13. The mandrel assembly (illustrated also in FIG. 2) is rotatable to axially register ladle 14, expandable arbor 15 or lubricant spray head 16 with the mold and the entire mandrel assembly is mounted upon a carriage l7axially traversable along rails 18 to permit in scrtion of the registered mandrel component axially into the mold.

DRIVE AND TRANSMISSION UNIT The main drive for horizontal centrifugal casting machine 10 is provided by drive motor 19, e.g., a solid obtained from the following.

pour rate'control oi arbor taken along lines 35 motor is operated at a rotary speed of approximately 900 rpm to produce a speed of approximately 500 rpm in rotary face plate 20 to which the arcuate sections of centrifugal mold 2! are secured. Because the drive and transmission unit are subject to multiple starting and stopping during operation, motor I9 desirably is cooled by a blower unit 23 which includes fan 24 driven by motor 25 and suitable ducting 26 communicating the drive motor interior with the external environment.

The drive end 27 of main drive motor 19 rotates a pulley 28 driving flexible belts 29 to 'apply torque to a larger diameter pulley 30 to obtain the desired reduction in speed between the drive motor and centrifugal mold 21. Because the belt load is too great for direct application to main shaft '31 of the drive and transmission unit,torque transmitted through belt 29 is transferred to the main shaft through a conventional bearing block assembly 32'and standard coupling unit 33. As is shown in FIG. I, the outer housing 34 of bearing block assembly 32 is fixedly secured to base 35 of the casting machine to support the belt load while a pair of bearings 36 permit rotation of shaft 37 within the bearing block assembly to transmit rotary force through coupling unit 33 to main shaft 31. The torque applied to main shaft 31 through coupling unit 33 then is transmitted to rotary face plate 20 secured to the hollow main shaft by bolts 38 to permit rotation of centrifugal mold 21 mounted to'the face plate (as will be more fully ex plained hereinafter).

The speed of main shaft 31 is monitored by a speed sensing and mold positioning assembly 39 (illustrated in FIGS. 3 and 4) which includes a selectively apertured wheel 40 mountedupon the shaft to pass between three proximity switches 41-43 secured to supports 44 mounted to block 45 on base 35. Uppermost proximity switch 41 is radially registered with six 'arcuately spaced apertures 46 inwheel 40to measure the rotary speed of shaft 31- by counting the number of actuations of. proximity switch 41 within'a-t'ixed period of time while lower proximity switch 42 registered with radially outer semicircular lip 47 of wheel 40 is employed to determine whether shaft 31 is rotating by sensing continued actuations of the proximity switch. The third proximity switch 43 serves to position rotary face plate 20 (and mold 21 mounted thereon) at a particular angular orientation with pulling assembly 48 (illustrated in FIG. 1) of the casting machine by aligning the proximity switch with protrusion 49 extending axially outward from wheel 40. Proximity switches, to achieve the foregoing results, are well known in the art and can be obtained commercially from the General Purpose Control Department of the General Electric Company.

To obtain the desired registration between protrusion 49 and proximity switch 43 (and the resultant registration between centrifugal mold 21 and pulling assembly 48), a small drive motor 50 (illustrated in FIG. I) is connected to the opposite drive end of the shaft of main drive motor 19 through a gear reducer 51 and an electric clutch 52 topennit slow rotation of main shaft 31 after termination of mold rotation at the end of a cast. as observed by proximity switch 42. Thus, with drive motor 19 stationary after the completion of a centrifugal cast, electrical clutch-52 is engaged and small drive motor 50 is energized 'to slowly rotate shaft3l through main drive motor 19 until protrusion 49 is registered with proximity switch 43 at which time energization of the small drive motor is terminated and the motor electric brake is'engaged to stop rotation of the mold. Clutch 52 then is disengaged, and the tapered piston of hydraulic cylinder 22 is inserted into a slot in rotary face plate .to' lock the plate in position.

Main shaft 31 is utilized not only to transmit torque to rotary faceplate 20 but also as a conduit to transmit fluid coolant to mold 21 mounted upon the face plate. The fluid coolant, typically water, enters axially outer annular chamber 53 through aperture 54 in water jacket 55 surrounding the end of shaft 31 remote from the mold and the coolant flows through bore 56 in the shaft to a central pipe 57 for axial transmission along the shaft. The fluid coolant then advances into annular chamber 58 formed between partition 59 and plug 60 whereafter the coolant flo'ws radially outward through aperture 61 in the shaft and flexible hoses 62 to pass serially through the-four'individual sections forming mold 21 (as will be more fully explained hereinafter with reference to FIG. 8). The coolant then returns through aperture 63 to axial flow channel 64 between shaft 31 and pipe 57 to return to annular chamber 65 by way of radial bore 66 in shaft 31. From annular chamber 65, the

plate 20 thereby locking-the four mold sections secured to the respective onesof orthogonally disposed jaws 86 into a composite cylindrical unit. Limit switchesBS are mounted upon the exterior of housing assembly 72 to measurethe outward extent of pistons 78, i.e., by actuation of the limit switches by vanes 89 carried upon rod 90 mounted on plate 79.

Because the axially outer and inner lock rings, identified by

reference numerals

84a and 84b, respectively,

of the mold locking unit may not contact tapered'faces 85a and 85b of mold gripping jaws 86 with equal force due to unequal thermal expansion of the jaws during casting, axially outer lock ring 840 is driven by an individual spring biasing means, such as theBellville washers 92, shown in FIG. 6, to compensate for the effects of thermal expansion. Thus, although rods 82 produce an equal axial advancement of tapered lock rings 84a and 84!: upon actuation of hydraulic cylinder 75, thermal expansion of gripping jaw'86 may produce a higher clamping force between one ring, i.e., inner ring 84b, and tapered face 85b of the gripping jaw then occurs between outer ring 840 and the gripping jaw. By dimensioning the inner radius of ring 84;: to engage the grippingjaw' before ring 84b, Bellville washer 92 situated adjacent ring Mo on rod 82 can absorb the axial load as axially inner ring 84 b is driven into firm contact with the associated tapered face on gripping jaw 86 to equalcoolant flows through aperture 67 within water jacket 55 to return to a heat exchange and pumping unit (not shown) for recirculation through the mold. A partition 68 serves to separate the streams of circulating coolant in the adjacent annular chambers at the endof shaft 31 while conventional face seals 69 inhibit leakage of coolant adjacent the shaft. v

Main shaft 31 is supported at the driven end .of the shaft by a spherical bearing 70 while a tapered roller bearing 71 is situated at the drive end of the shah to absorb both radially and axially directed shaft loads. In conventional fashion, tapered roller-bearing 71 is positioned between shaft 31 and housing assembly 72 at a fixed axial location while spherical bearing 70 is axially slidable between the shaft and housing assembly to inhibit axialloading of the bearing. Both bearings are lubricated by oil circulating between the rotating shaft and the stationary housing assembly by way of oil intake and

exhaust orifices

73 and 74, respectively,

within the housing assembly.

MOLD ASSEMBLY AND STRIPPING UNlT A pair of hydraulic cylinders 75 mounted on plate 76 fixedly secured to base 35 serve to reciprocally drive mold locking unit 77 in an axial direction thereby securing mold 21 in position for casting. To effect locking of the mold, pistons 78 within cylinders 75 reciprocally drive annular plate 79 and the reciprocal motion of the plate is transmitted through the radially outer raceway of tapered roller bearing 80m axially traverse the rotary bearing members and the inner raceway of the bearing along shaft 31. Because the inner raceway of bearing 80 also forms an integral part of back plate 81, the back plate and rods 82 fixedly secured along the periphery of the back plate also are uaversed in an axial direction by actuation of pistons 78. Axial movement of rods 82 draws the tapered annular face 83 of lock rings 84 against the tapered radially outer faces 85 of mold gripping jaw 86 to radially slide the jaws within a T-shaped aperture 87 (shown in FIG. 5) of rotary face ize the force distribution at axially opposite ends of the assembled mold.

A sectionalized centrifugal mold 21 preferred for utilization in this invention is depicted in H6. 7-in' a machine mounted configuration, i.e., with associated gripping jaws 86 of the casting machineflhe mold preferably is formed of four arcuate sections 2lq-2ld having interlocking axial edges 93 to mate upon juxtaposition of the sections thereby forming a composite mold capable of retaining molten metal therein. The interlocking edges 93 of mold 21 are similar to the edge configuration of the mold disclosed inBaumarm et al U.S.' Patent Application, Ser. No. 220,286 (the disclosure'of which is incorporated herein by reference). The edges of mold 21, however, are designed-to be disengaged or engaged upon simultaneously moving all four sections along perpendicularly oriented axes. To obtain the ready dismemberment of the mold while} inhibiting leakage of molten metal from the mold, two diametrically opposite mold sections, i.e., sections 210 and 21c, are provided with longitudinal edges having an angular, preferably orthogonal, step 93a which functions as a seat for the longitudinal edges 93!: of the adjacent mold sections. The radially inward extending lips 94 at the axial ends adjacent mold sections also have edges 940 with a complimentary angular taper, preferably radial. to snugly mate upon juxtaposition of the mold sections.

electric machines, the interior of each mold section preferably is notched, in conventional fashion, to form a plurality of triangular grooves 91 extending in a substantially parallel direction into each mold section to produce the cooling fins desirable for the cast frame without substantially inhibiting stripping of the mold sections from the frame. To effect such result, the width of the grooves should taper at a suitable angle, e.g., .030/in. n 230, with penetration into the sidewall of the mold.

Each mold section is individually secured to a mold gripping jaw of the casting machine by bolts 95 and a v7 1 suitable fluid connector, preferably a commercially available quick disconnect connector 96 and an elbow 97 (shown in FIG. 8) admits fluid coolant from flexible hoses 62 to the region between the mold section and the jaw fixedly secured thereto. Preferably, the coolant is circulated in dual streams serially through the composite mold jaw units (as shown in FIG. 8) before returning to'flow chamber 64 in shaft 31 for return to the heat exchange and coolant pumping unit associated with the machine.

Because lock rings 84 clamp the mold sections into a composite unit, no provision (other than tapered face 85 on the mold gripping jaws) is required along the outer periphery of the mold sections to secure one mold section to the other.'Four cars 99, however, (shown in FIG. 7) are provided on each mold section to maintain the sections in juxtaposition in order to facilitate changing molds within the casting machine.

Thus, the change the moldfor a new frame size, pins 98 can be inserted through the ears of the mold sec.- tions to maintain the sections in juxtaposition whet-eatter the composite unit may be supported upon arbor of mandrel assembly 13. Mandrel assembly carriage 17 then is moved axially into the machine permitting the mold sections to be'bolted to gripping jaws 86-of the machine. The pins retaining the mold sections in juxtaposition then can be manually removed and the arbor withdrawn axially from the mold to permit the initiation of casting. As was stated earlier, each gripping jaw 86 to which the individual mold sections are secured has a tapered radially outer face 85 at axiallybppositeends 'ofthe mold to permit the application of a radially inward force to the mold sections upon the axial traversal-of lock rings 84 across the faces. One edge of the jaw, the axially inner edge, has a T-shaped protrusion 100 to be slidably-received within T-shaped aperture 87 of rotary face plate to permit the jaw to slide in a radial direction. The radially outer face of each jaw also has apulling bracket 101 for engagement with .-pistons 102 (shown in FIG. 1) of hydraulic pulling assemblies 48 fixedly secured to the stationary main back plate. 104 of the centrifugal casting machine;

The pulling assembly utilized to position the mold I sectionsfor engagement by lock rings 84and for stripping the mold sections from the cast is illustrated more clearly in FIG. 9 and generally comprises a large hydraulic pulling cylinder 105, inder, fixedly secured to back plate 104 by brackets 106 and angles 106a. Piston 102 of the pulling cylinder has a tapered bifurcated member 107 threadedly engaged at the forward end of the piston to engage pulling brackets 10! along the radially outer face of gripping jaws 86 while an elongated bracket assembly 108 extends outwardly from bifurcated member 107 to support small diameter piston cylinder 109 which drives dual lockpins 110 through aligned apertures 111 in the bifurcated member and the pulling brackets of the jaws upon admission of hydraulic fluid to the small diameter cylinder. Dual limit switches switches ll2'and1l3 also are mounted along the outer housing of small diameter cylinder 109 to be engaged by lockpins 110 to indicate the position of the lockpins relative to bifurcated member 107. Similarly, piston 102 of the large pulling cylinder also carries a lower platform 114 having dual guide rods llS mounted thereon to actuate

limit switches

116 and 117 by vanes 118 mounted on the guide rods toindicatc the extent of piston 102 toward the mold. in order to permit both the positioning of the four arcuate sections of mold 21 into a cylindrical structure prior to casting, and the stripping of the mold sections simultaneously from the cast, four pulling cylinders 105 are mounted at 90 intervals about main back plate 104 to radially align bifurcated members 107 with pulling brackets 101 of gripping jaws 86.

' To assure that the fourpulling pistons operate simultaneously during stripping of the mold from the cast, the four pulling cylinders are fed hydraulic fluid through commercially available flow dividers (not shown) to synchronize thepulling of the mold sections from the cast notwithstanding differing adhesive forces between the cast and the separate mold sections. Flow dividers to achieve this result typically include four hydraulic pumps having a single interconnected shaft to assure the. pumping of equal quantities of hydraulic fluid to each of pulling cylinders ,105. Thus, all the pulling pistons are withdrawn into their respective cylin- V ders at a uniform rate and there is substantially no withdrawal until all mold sections are broken loose from the a can be connected in series in cast. a Y

Should 'theslip. rate of the pumps forming the hydraulic fluid flow divider'become excessive, two flow diviers the hydraulic lines, e .g.,

a flow divider capable of pumping seven gallons'per e.g., a 6 inch diameter cylminute per cylinder could be serially connected with a flow divider capable of pumping 35 gallons per minute per cylinder. The lower volume flow divider-then functions to reduce the slip between pulling pistons until the mold sections are disengaged from the cast whereafter alsuitable valve by-passing the lower volume flow divider oould be actuated to permit a more rapid synchronized withdrawal of the pulling pistons into their respective cylinders'under the control of the higher vol ume flow divider.

MANDREL ASSEMBLY truding outwardly frorn'an upwardly extending centerpost 120 at angularlydisplaced locations, shown at 90 intervals, to permit axial registration of each of the outwardly extending components with the assembled mold upon rotation of the centerpost. Ladle l4 issubstantially identical to the ladle described in heretofore cited Baumann et al U.S. Patent Application Ser. No. 220,285 (the disclosure of which is incorporated herein) and generally includes a cylindrical vessel 121 having a ceramic lining 122 and a metallic outer sheathing 123. In conventional fashion, a rectangular 'opening 124 is provided along the top of the ladle to admit and remove molten metal from the ladle and the ladle is secured to a rotatable shaft 125 to permit tilting of the ladle when discharge of molten metal from the ladle is desired. A back plate 126 also is mounted be tween the ladle and rotatable shaft 125 to mate with opening 127 in hood assembly 128 to entirely enclose the rotating mold during the pouring of molten metal into the mold. V

Tilting of the ladle to pour molten metal therefrom is accomplished utilizing ladle rotating mechanism 129 (illustrated in FIG. 10 and lllwhich mechanism gen erally includs a hydraulic cylinder 130 fixedly secured within the mandrel assembly for driving rack 131

Claims

1. A horizontal centrifugal casting machine permitting the sequential casting of a plurality of finned cylindrical structures, said machine comprising a rotary drive including a rotary face plate, a plurality of separable mold sections having interlocking longitudinal edges, each of said sections being movably secured to said face plate, means connected to each of said mold sections for moving said sections radially relative to said face plate to arrange the sections in juxtaposition to form a cylindrical mold capable of confining liquid material to be cast therein and for moving said sections apart to free material cast in the mold, said means for moving said sections being connected to each of said mold sections and being operable to move said sections to form said mold, means connecting said rotary drive to said cylindrical mold to permit rotation of said mold, means for pouring molten material into said mold during rotation of said mold to cast said cylindrical structure and means for stripping said mold sections from said cast to produce a finned cylindrical structure independent of the mold into which said molten material was poured.

2. A horizontal centrifugal casting machine according to claim 1 further including means for inserting an arbor within said mold while it is secured to the face plate subsequent to casting said cylindrical structure and means for expanding at least a portion of said arbor radially outward to contact the interior of said cast structure prior to stripping of said mold sections from said cast structure.

3. A horizontal centrifugal casting machine permitting the sequential casting of a plurality of finned cylindrical structures, said machine comprising a rotary drive, a plurality of mold sections having interlocking longitudinal edges, means connected to each of said mold sections for moving said sections into juxtaposition to form a cylindrical mold capable of confining liquid material to be cast, means connecting said rotary drive to said cylindrical mold to permit rotation of said mold, means for pouring molten material into said mold during rotation of said mold to cast said cylindrical structure and means for stripping said mold sections from said cast to produce a finned cylindrical structure independent of the mold into which said molten material was poured, including means for inserting an arbor within said mold subsequent to casting said cylindrical structure and means for expanding at least a portion of said arbor radially outward to contact the interior of said cast structure prior to stripping of said mold sections from said cast structure, wherein said means for pouring molten material into said cylindrical mold includes ladle means having an opening therein and means for tilting said ladle to pour molten material from said opening, said ladle means and said arbor extending outwardly from a common rotatable mandrel.

4. A horizontal centrifugal casting machine according to claim 1 further including tapered rings for clamping each of said mold sections into a cylindrical mold, said rings being axially movable relative to said cylindrical mold to apply radial force to said mold sections by wedging said tapered rings respectively against tapered portion of the outer periphery of the mold sections at axially inner and outer locations thereon, and biasing means driving at least one of said tapered rings against the tapered portions of the mold sections to equalize the radial pressure produced by the individual rings at said inner and outer locations.

5. A Horizontal centrifugal casting machine for casting finned cylindrical structures comprising a rotary drive, a plurality of arcuately displaced mold sections, means for moving said mold sections into juxtaposition to form a closed cylindrical mold, means connecting said rotary drive to said cylindrical mold to permit rotation of said mold, means for pouring molten material within said mold during rotation to centrifugally cast the finned cylindrical structure therein, means for registering said cast with an expandable arbor, means for inserting said arbor within said cylindrical mold, means for expanding at least a portion of said arbor radially outward to contact the interior of said cast structure and means for stripping said mold sections from said cast structure with said arbor in said cast structure, said means for stripping comprising a plurality of pulling assemblies (48) mounted at spaced intervals on the casting machine around the periphery of said mold, each of said pulling assemblies having a piston (102) that is reciprocally operable to engage pulling brackets (101) mounted on the respective mold sections, and a mold positioning assembly (39) that is operable to position each of said pulling assembly pistons in alignment, respectively, with one of the mold pulling brackets after material has been cast in the mold.

6. A horizontal centrifugal casting machine according to claim 5 further including means for circulating a liquid coolant in thermal contact with said mold sections to remove heat therefrom during casting.

7. A horizontal centrifugal casting machine according to claim 5 further including means for registering said stripped mold sections with a lubricant spray head, means for traversing said spray head axially within said sections, and means for spraying lubricant along the interior of said mold sections during said traversal prior to moving said sections into juxtaposition for a subsequent cast.

8. An invention as defined in claim 5 including an auxiliary motor (50) mounted on said casting machine and coupled to selectively rotate said rotary drive responsive to signals generated by said mold positioning assembly (39) thereby to move the pulling assembly pistons into alignment with the mold pulling brackets.

9. A horizontal centrifugal casting machine according to claim 5 wherein said cylindrical mold is formed of four arcuate sections having a plurality of axially extending grooves notched therein in a substantially parallel direction, and said means for stripping said mold sections from said cast include gripping means for fixedly engaging the radially outer surface of each of said four arcuate sections and means for simultaneously actuating said gripping means to strip said sections from said cast structure by applying a force to each said section in a direction perpendicular to the axis of the cylindrical mold.

10. An invention as defined in claim 9 wherein said means for simultaneously actuating the gripping means comprises means of synchronizing the pulling forces applied to each of the mold sections by said piston thereby to withdraw all of the pulling pistons away from the axis of rotation of said mold at a uniform rate.

11. An invention as defined in claim 10 wherein each of said pistons is mounted respectively in a hydraulic cylinder, and wherein said means for synchronizing the pulling forces comprises a flow divider operably connected to the hydraulic supply lines mounted on said machine to supply actuating fluid to each of said cylinders.

12. A horizontal centrifugal casting machine for casting finned cylindrical structures comprising a rotary drive, a plurality of arcuately displaced mold sections, means for moving said mold sections into juxtaposition to form a closed cylindrical mold, means connecting said rotary drive to said cylindrical mold to prevent relative movement therebetween and to permit rotation of said mold, means for pouring molten material within said mold during rotation to centrifugally cast the finned cylinDrical structure therein, means for registering said cast with an expandable arbor, means for inserting said arbor within said cylindrical mold, means for expanding at least a portion of said arbor radially outward to contact the interior of said cast structure and means for stripping said mold sections from said cast structure with said arbor in said cast structure wherein said means for pouring molten material into said closed cylindrical mold includes a ladle and means for tilting said ladle to pour molten material from said ladle into said mold, said ladle and said expandable arbor being mounted upon a common vertically disposed mandrel, and said means for registering said cast structure with said expandable arbor includes means for rotating said mandrel to axially align said expandable arbor with said cast structure and means for producing axial motion between aaid mandrel and said cast structure to insert said expandable arbor within said cast structure.

13. A horizontal centrifugal casting machine according to claim 12 wherein said expandable arbor includes a plurality of arcuately shaped plates, each of said plates being individually driven into contact with the interior of said cast structure upon expansion of said arbor.

14. A horizontal centrifugal casting machine for casting finned cylindrical structures comprising a rotary drive, a plurality of radially movable arcuate sections, said sections being capable of forming a cylindrical mold upon a radial traversal of said sections to a juxtaposed position, drive means secured to the outer periphery of said sections for radially traversing said sections into a substantially closed cylindrical disposition tapered lock ring means situated adjacent the outer periphery of said mold sections, means for producing axial movement between said tapered lock ring means and a radially tapered surface on the outer periphery of said mold sections to apply a radial inward force upon each of said mold sections to lock said sections into a closed cylindrical mold capable of retaining molten material therein, means for applying said rotary drive to said locked sections to rotate said mold about the mold axis, said rotary drive including a rotatable face plate having a plurality of radially extending channel-like apertures (87) that are each operable to secure one of said mold sections in juxtaposition to said face plate thereby to prevent axial movement of said mold sections while permitting radial movement of the mold sections, means for pouring molten material into said rotating mold to cast a finned cylindrical structure therein, means for producing axial movement between said tapered lock ring means and said mold sections to release the radially inward force on said sections, and means for actuating said drive means to apply a radial force to said mold sections to strip said sections from said cast structure.

15. A horizontal centrifugal casting machine according to claim 14 wherein said lock ring means include two axially displaced rings each having a tapered radially inner face, means for traversing both said rings simultanneously toward engagement with said mold sections to apply a predetermined radial force to said sections from at least one said ring and resilient biasing means situated between at least one of said rings and said traversing means to apply an axial force to the associated ring tending to lock said ring against the tapered face of the mold section and balance the force applied by both rings.

16. A horizontal centrifugal casting machine according to claim 15 further including means for circulating a fluid coolant in thermal contact with the interior of said mold sections during casting of said cylindrical structure.

17. A horizontal centrifugal casting machine for casting cylindrical structures comprising rotary drive means, a plurality of pulling means disposed at arcuately displaced locations about a central rotary axis, said pulling means having an extendable member securable to an arcuate section of a cylindRical mold, means for extending the members of said pulling means to juxtapose said mold segments thereby forming a cylindrical mold, means for transmitting torque from said rotary drive to said cylindrical mold, means for pouring molten material into said rotating cylindrical mold to centrifugally cast a cylindrical structure, means for inserting an arbor axially within said cylindrical structure, means for expanding said arbor to contact the inner surface of said cast structure, means for actuating said pulling means to strip said arcuate sections from said cast structure to isolate a finned cylindrical structure formed entirely of solidified material, said stripping means radially displacing said mold sections relative to said cast to dispose said stripped sections parallel to the disposition of said sections in the juxtaposed mold, means for axially moving the arbor and removing said cast cylindrical structure from the interior of said mold sections, and means for actuating said pulling means to reassemble said mold sections into a cylindrical mold.

18. A horizontal centrifugal casting machine according to claim 17 wherein said pulling means are fixedly secured to a non-rotatable surface upon said casting machine, and further including means for disengaging said pulling means from said mold sections prior to casting said cylindrical structure and axially traversable retaining ring means movably mounted on said machine for maintaining said mold sections in juxtaposition upon disengagement of said pulling means therefrom.

19. A horizontal centrifugal casting machine for casting finned cylindrical structures comprising a first rotary drive, a plurality of radially movable arcuate sections, said sections being capable of forming a cylindrical mold upon a radially inward traversal of said sections to a juxtaposed position, reciprocal drive means secured to the outer periphery of said sections to position said sections in a substantially cylindrical disposition, means for locking said sections into a closed cylindrical mold, means for disengaging said reciprocal drive means from said sections, means for applying said rotary drive to said cylindrical mold, means for pouring molten material into said cylindrical mold during rotation of said mold, means for disengaging said first rotary drive from said cylindrical mold, means for engaging a second rotary drive to said mold to rotate said mold at a reduced speed relative to said first rotary drive, means for terminating rotation of said mold at a predetermined angular position, means for engaging said reciprocal drive means with said mold sections and means for actuating said reciprocal drive means to apply a force perpendicular to the axis of said cylindrical mold to said sections to strip said mold sections from the structure cast within the mold.

20. A horizontal centrifugal casting machine comprising a plurality of arcuately shaped mold sections having longitudinally extending edges of complimentary configuration to seat the edge of one mold section within the edge of an adjacent section upon juxtaposition of said sections into a cylindrical mold, means within said mold sections to secure said sections to radially movable jaws within the centrifugal casting machine, said jaws being adapted to receive molds of diverse diameter and having a tapered surface along at least a portion of the outer periphery of the jaws, means for securing said jaws to pulling means mounted on the casting machine, retaining ring means slidably mounted along the tapered surface of said jaws to apply radial force to said mold sections subsequent to the juxtaposition of said sections, clamping means along the radially exterior face of said jaws to permit engagement of said jaws by pulling means, means for engaging and disengaging said pulling means from said jaws, means for rotating said cylindrical mold, means for pouring molten material into the interior of said mold to cast a cylindrical structure therein, means for terminating rotation of sAid mold at a predetermined angular position to register said clamping means with said pulling means, means for advancing said pulling means into engagement with said clamping means, means for releasing said retaining ring from said jaws and means for actuating said pulling means to radially strip said mold sections from said cast structure.