Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS3821980 A
Publication typeGrant
Publication dateJul 2, 1974
Filing dateJan 24, 1972
Priority dateJan 24, 1972
Also published asDE2302761A1, DE2302761B2, DE2302761C3
Publication numberUS 3821980 A, US 3821980A, US-A-3821980, US3821980 A, US3821980A
InventorsBahn W La, Nary R Mc, W Smith
Original AssigneeGen Electric
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Apparatus for automatically stripping a sectionalized mold from a cast
US 3821980 A
Images(11)
Previous page
Next page
Description  (OCR text may contain errors)

United States Patent 1191 LaBahn et al.

1 1 APPARATUS FOR AUTOMATICALLY STRIPPING A SECTIONALIZED MOLD FROM A CAST [75] Inventors: William C. LaBahn, Scotia; Robert G. MacNary, Elnora; William R. Smith, Ballston Lake, all of NY.

[73] Assignee: General Electric Company,

Schenectady, NY.

22 Filed: Jan. 24, 1972 21 Appl. No.: 220,280

[52 U.S.Cl. ..164/40l,l64/l3l 51 Int. Cl ..B22d29/06 5s FieldofSearch ..l64/13l,40l,403,404,

[56] References Cited UNITED STATES PATENTS 3,662,815 5/1972 Bouyt 164/404 X I 1,754,106 4/1930 Hurst 164/404 1,776,547 9/1930 carringtonu 164/404 1,992,241 2/1935 Sargent 164/295 2,085,726 7/1937 Campbell 164/288 X 2,754,558 7/1956 Glock 164/404 3,142,106 7/1964 Wise ..164/404 X 3,488,692 l/1970 Oda.., 164/404 UX 2,217,140 10/1940 Smith....; 249/161 X 3,635,613 1/1972 Marsh 425/62 Primary Examiner-J. Spencer Overholser Assistant Examiner-John S. Brown Attorney, Agent, or Firm-Vale P. Myles et a1.

[57] ABSTRACT A highly automated mold stripping machine is described wherein a single jaw sequentially strips mold sections from the cast and subsequently reassembles the stripped sections into a composite unit after removal of the cast from the interior of the stripped sections. A vertically extending, radially expandable arbor serves to retain the cast in position during stripping and dual pistons of diverse diameter drive the stripping jaw into engagement with the mold sections. As each self-supporting mold section is stripped from the cast, the, section is released adjacent the edge of the turntable supporting the cast whereafter the arbor is retracted from an engaged position with the cast interior and the mold and stripped cast section are rotated independently of the arbor to register the strip ping jaw with a succeeding mold section. After all mold sections-have been stripped from the cast, the cast is axially removed from the interior of the stripped sections and the jaws of the stripping machine are again actuated to automatically reassembly the mold for a subsequent cast.

6 Claims, 12 Drawing Figures PATENIEUJIJL 2 m4 sum mar 11 PATENTEDwLamn 382L980 sum 02 or 11 PATENTEUJUL 2 I974 41 f FIG. 4

sum our 11 PATENTEDJHL 21914 3.821.980 sum mar 11 @@@@@m j 7///&

D QQQQQQQ QE Z2 PAIENIEIJJUL 2 I974 SHEET 07M 11 T'IOLD DISASSEFIBLE ST EPPING RELAY CONTACTS X-' CLOSED MOLD DISASSEVIBLE TABLE ROTATION STEPPING RELAY FIG. 7

FUNCTION INITIATED PISTON 4-6 TO VIOLD PISTON 34- TO MOLD PINS DOWN EXPAND ARBOR I6 PISTON 34 FROM I"IOLD PISTON 46 FROM MOLD PINS UP PISTON 4 FROM MOLD CONTRACT ARBOR INITIATE TABLE. ROTATION CONTACTS FUNCTION INITIATED I X K SIDEIAT SAW 2 X x ROTATE. I80

3 x x SIDEZAT JAw 4 x x ROTATE 90 5 x x 5IDE3AT JAW e x x ROTATE I80 '7 x x SIDEIAT (MW 8 x STAND STILL mmnmm" 2 m FIGS PATENTEUJUL 2 I914 arm 09 or 11 FIG. ID

PATENTEDJUL 219 3.821.980

sum 11 or n TIOLD ASSEMBLE STEPPING RELAY CONTACTS FUNCTION )NITIA'TED pas I- 2 3 4- 5 X PISTON 46 To FIOLD 2 X PISTON 34 To MOLD 3 X PlsToN 34 FROM HOLD 4 X PISTON 46 FROM MOLD 5 X IN ITJATE TABLE ROTATDON X= CLOSED MOLD ASSEHBLE TABLE ROTATION STEPFING RELAY PIC-d2 APPARATUS FOR AUTOMATICALLY STRIPPING A SECTIONALIZED MOLD FROM A CAST This invention relates to a method and apparatus for disengaging a mold from a cast objectand, in particular, to a highly automated method and apparatus for stripping a dismemberable mold from a cast in a manner permitting ready reassembly of the mold by the stripping machine.

The physical shape of molds employed for casting shaped objects and the manner of disengaging a mold from a cast generally have varied dependent upon diverse factors such as the size of the cast to be made, the number of casts required from each mold, the economic cost of the mold, et cetera. For example, smooth surfaced bearings heretofore have been cast utilizing mold sections mechanicallyjoined by sealing blocks secured along the longitudinal edge of the mold sections with disassembly of the mold being accomplished by removing bolts securing the sealing blocks in position and pulling the mold sections from the cast structure. While such technique is suitable for small cast objects having a smooth outer surface, to minimize theadhesion between the cast and the mold sections, larger cast objects generally have used more sophisticated automated means for removing the cast from the mold. For example, it heretofore has been proposed that cores be removed from casts by spraying the core interior with a cooling fluid to contract the core from the uncooled cast with subsequent vibration of the core serving to disengage the two structures. Other techniques suggested for removing centrifugally cast cylindrical bodies from a mold include expandable tongs for engaging the interior of the cast to apply an axial force retracting the cast from the mold while dual section molds have utilized a sprocket drive meshed with the sprocketed exterior of the mold for cast removal purposes. Other casting devices employ mechanical bracing to retain brake drums in position for centrifugal casting with the mechanical bracing being removed subsequent to casting to disengage the lined drum from the casting machine. While the foregoing cast removal techniques have been suitable for casts wherein the adhesion of the cast to the mold is relatively small, the foregoing techniques generally are not suitable for large diameter, irregularly shaped objects having significant adhesion between the cast and the mold. Moreover, when the mold employed for casting is composed of sections having significant weight,e.g., in excess of 500 pounds, re-assembly of the mold is a formidable and time consuming task. i

lt is therefore an object of this invention to provide a highly automated mold stripping machine capable of reassembling the mold after removal of the cast.

it is also an object of this invention to provide a stripping machine having an arbor which can be disengaged from mold interior to permit rotation of the mold without mounting the arbor on bearings.

It is a further object of this invention to provide a mold stripping machine having an expandable arbor of superior design. i

It is a still further object of this invention to provide a method of disassembling a mold from a cast in a manner permitting ready reassembly of the mold upon removal of the cast from the interior of the stripped sections.

These and other objects of this invention generally are achieved utilizing a stripping machine having an arbor disposed at an attitude to axially accept a cylindrically shaped cast and mold section clamping means situated at a radially removed attitude from the arbor to fixedly grip at least one section of the mold when the clamping means are moved into engagement therewith. The clamping means then is radially removed from the arbor by suitable pulling means to apply force to the engaged section of the mold in a direction perpendicular to the axis of the arbor to strip the mold section from the cast and the stripped section is maintained at a radially displaced location relative to the cylindrically shaped cast in a plane substantially parallel to the plane of the section upon the cast. After each of the cast sections is sequentially stripped from the cast and the cast removed from the interior of the stripped sections, the clamping means are again actuated to drive individual sections of the mold towardthe arbor to reassemble the mold into a cylindrical structure.

Desirably, the stripping machine also is characterized by a fixedly positioned expandable arbor extending axially through a rotatable turntable. The mold and stripped sectionsthen are seated upon the turntable permitting rotation of the mold into registration with the stripping means and simultaneous removal of the stripped sections from interference with the stripping means. Because the stationary mounting of the arbor transmits the stripping force upon the mold sections directly to the base of the machine, "the size of the bearings required for rotation of the mold is-significantly reduced relative to stripping machines having a rotatable rotor.

Although this invention is described with particularity in the appended claims, a more complete understanding of the invention may be obtained from the following detailed description ofa specific embodiment of a casting machine built in accordance with this invention when taken in association with the appended drawings wherein:

FIG. 1 is a partially exposed elevation view of a stripping machine in accordance with this invention,

.FIG. 2 isan end view illustrating the carriage mounting for the pulling assembly of the stripping machine,

FIG. 3 is a top view taken along lines A-A of FIG. lportraying the seating of the pulling assembly about the stationary arbor of the stripping machine,

FIG. 4 is a elevation view of the pin drive assembly employed to secure the jaws of the stripping machine to each mold section,

FIG. 5 is a elevation view of the drive pin positioning assembly of this invention,

FIG. 6 is a diagram of the hydraulic control system of the stripping machine illustrating schematically the electrical controls for automatically stripping the mold from the cast,

FlG. 7 is achart illustrating the sequential operation of the stepping relays employed to control the pulling assembly and turntable of the stripping machine during stripping of the mold from the cast,

FIG. 8 is a plan view of the underside of the rotary FIG. is a top view taken along lines BB of FIG.

FIG. 11 is a schematic illustration of the hydraulic and electrical control systems for automatically reassembling the mold, and

FIG. 12 is a chart illustrating the sequential operation of the stepping relays employed to control the pulling assembly and turntable during reassembly of the mold.

A stripping machine 10 in accordance with this invention is illustrated in FIG. 1 and generally comprises a mold stand 11 for retaining sectionalized mold 12 in a vertical disposition during stripping and a pulling assembly 13 suited in a confronting attitude relative to the mold for stripping the individual mold sections from underlying cast 14. The entire machine is mounted on a single stationary base 15 which supports both the pulling assembly and the mold stand at a desired span relative to each other.

Mold stand 11 basically includes an arbor l6 fixedly secured to stationary base 15 and supported at its lower periphery by a gusseted collar 17 having a lower flange 18 bolted to the stripping machine base to absorb a portion of the forces transmitted through the stationary arbor to the base during stripping. Supports 19 for four caster wheels 20 also are bolted to base 15 to rotatably support a main turntable 21 circumferentially disposed about arbor 16 above gusseted collar 17. The main turntable, in conventional fachion, is spaced apart from the central arbor by a short distance, e.g., IO mils, to permit rotation of the turntable relative to the stationary arbor and a sprocket 22 is fixedly secured to ring 23 at the lower end of gussets 24 supporting the turntable to apply rotational torque to the turntable from drive motor 25 (illustrated in FIG. 2) when rotation of the mold is desired. An upper turntable 26, also circumferentially disposed about and radially spaced apart from arbor 16, serves as the actual support for the mold during stripping to insulate cam follower bearings 89 of the turntable from the heat of the mold. The upper turntable is secured to the top of the main turntable by bolts 27 extending through lower flange 28 to which the weight of the mold upon the upper turntable is transmitted by means of eight equally spaced gussets 29. A ring 30 also is situated atop the upper turntable adjacent central arbor 16 to shield the annular region between the turntable and the arbor from contamination by falling debris during operation operation of the stripping machine.

Coarse registration of the mold sections with pulling assembly 13 preferably is achieved utilizing a plurality of limit switches 31a-31e positioned atop the end of base 15 remote from the pulling assembly upon activation by earns 32 fixedly secured to the lower surface of the main turntable. Typically, earns 32 are disposed at each quadrant of the main turntable at a radial distance from central arbor 16 to de-energize drive motor 25 after a predetermined angular rotation of the turntable by activating selective ones of limit switches 31, (as will be discussed more fully heereinafter with reference to FIG. 6).

Pulling assembly 13 employed to strip the mold sections from the cast is characterized by a jaw 33 threadedly engaged to the forward end of hydraulic piston 34 and supported at opposite ends within pulling assembly housing 35 by guide rods 36 extending through aligned sleeved apertures within support plates 37 of the pulling assembly housing. The face of the pulling jaw proximate mold 12 is provided with slots 38 to receive brackets 39 located along the outer periphery of the mold sections while vertically extending apertures 40 are provided through the jaw face proximate the mold for the passage of high carbon steel lock pins 41 employed to interlock the mold sections and the jaw when the lock pins are driven downwardly subsequent to insertion of the mold brackets into the slots of jaw 33. Piston 34 primarily serves to transmit a high pulling force to the jaws for stripping the brackets from the cast and typically is characterized by a large diameter piston cylinder 42, e.g., a 12 inch piston cylinder, to apply a force of approximately I00 tons to the mold section being stripped.

Because of the large diameter necessarily employed for piston cylinder 42 to attain the force levels required to strip the mold sections from the cast, piston 34 necessarily moves at a slow speed for a given hydraulic pressure and fluid orifice to the cylinder. To achieve more rapid movement of jaw 33 without loss of stripping power, piston cylinder 42 is mounted within a car riage 43 supported by roundway bearings 44 (illustrated more clearly in FIG. 2) upon rails 45 to permit reciprocal motion of the carriage along the rails. The drive power for the carriage is supplied by a small diameter piston 46 having a forward end fixedly secured to the underside of the carriage by a cylinder rod mounting block 47. The piston itself is axially received, in conventional fashion, within piston cylinder 48 fixedly secured to base 15 of the stripping machine by riser block 49 and supports 82. Because of the small diameter of piston cylinder 48, carriage 43 carrying pulling assembly housing 35 and jaw 33 can be traversed rapidly toward mold 12 with the large diameter of piston cylinder 42 secured to the pulling jaw 33 permitting application of the required pulling force to the mold sections for stripping the sections from the cast. In general, a diameter ratio of at least 2:1 is desirable for pis ton cylinders 42 and 48 with piston cylinder 42 typically having a 12 inch diameter as opposed to a 4 inch diameter for piston cylinder 48 to obtain an approximately l:l5 speed ratio between the driven pistons. A plurality of limit switches 50 also are disposed along the length of the carriage traversal to be engaged by vanes 51 for controlling the admission of hydraulic fluid to piston cylinders 42 and 48 to regulate travel of the carriage in a manner to be more fully explained hereinafter.

A support 52 is fixedly secured atop support plates 37 of carriage 43 to bear against central arbor 16 when the carriage is driven by piston 46 to a position proximate the mold to terminate travel of the carriage. As can be seen more clearly in FIG. 3, the forward end 53 of support 52 is arcuately curved to receive the upper portion of cylindrical arbor 16 thereby inhibiting bending of the arbor in cantilever fashion upon the application of pulling force to the mold sections. Because arbor 16 is fixedly secured to base 15, the force applied to the mold section during stripping is transmitted directly to the base significantly reducing the size of the bearings required for rotation of the mold relative to a machine having a rotary arbor.

The end ofjaw 33 remote from the mold is fixedly secured to the lower end of lock pin support 55 to continuously maintain lock pins 41 in an aligned vertical disposition relative to apertures 40 extending through the jaw. As can be seen from FIG. 4, the upper ends of verfrom the piston cylinder with the end of the drive piston remote from cylinder 58 being threadedly engaged within a bracket assembly 60 to which lock pins 41 are fixedly attached by means of nuts 61. A pair of guide pin assemblies 62 also are mounted in a vertical disposition atop bracing 57 and serve to direct the lock pins through apertures 40 as the pins are reciprocally driven by the hydraulic piston.

Limit switches 63 controlling the upward and downward traverse of the lock pins (by controlling electromagnetic valves regulating the admission and exhaust of hydraulic fluid to piston cylinder 58) are supported upon bracket 64 mounted to lock pin bracing 57. As is illustrated in FIGS. 1 and 5, the limit switches themselves are actuated by a pair of vanes 65 mounted on rods 66 extending vertically through apertures in bracket assembly 60 and the upper and lower ledges of bracket 64. Springs 67 serve to bias rods 66 toward a position juxtaposing the vanes with their associated limit switches while a pair of bushings 68 are mounted at spaced apart axial locations along each rod to limit the traverse of the vanes relative to the limit switches. Thus, when lock pins 41 are actuated to descend from the upward position illustrated in FIGS. 1 and 4, rods 66 do not descend until bracket assembly 60 engages lower bushings 68a disposed proximate bracket 64 whereafter rods 66 are driven by bracket assembly 60 to move one of vanes 65 into proximity with its associated limit switch 63 to disengage the valve supplying hydraulic fluid to the piston cylinder and initiate a subsequent step of the stripping operation (as will be more fully explained hereinafter).

Stripping of the mold from the cast is substantially completely automatic (as illustrated in FIGS. 6 and 7) and is controlled by a commercially available ten posi tion mold disassembly stepping relay (MDSR) for gencrating triggering signals on selected terminals of the stepping relay to initiate the sequential functions illustrated in FIG. 7a while rotation of main turntable 21 is controlled by an eight position stepping relay TRSR for sequentially triggering the table rotation functions illustrated in the chart of FIG. 7b. Typically, the stepping relays generate output signals on successive output terminals upon application of a triggering input signal, e.g.. from a limit switch, to the relay although other variations of sequential switching (such as is illustrated in FIG. 7b for TRSR) can be utilized ifdesiredQBecause all the jaw drives of the stripping machine are hydraulically operated, energization ofa selected contact is employed to initiate operation of selective electromagnetic valves controlling the admission of hydraulic fluid to the piston cylinders in conventional fashion. Stepping relays capable of functioning in the sequence disclosed in FIG. 7 can be obtained commercially from Struthers Dunn, lnc.. Putnam, N. J. while solenoid pilot operated hydraulic control valves for regulating admission of hydraulic fluid to the cylinders are commercially available from Logansport Machine. Inc. Logansport, Ind.

Initially, the mold to be disassembled is lowered axially upon central arbor 16 with pins 69 extending axially from the end of the mold being inserted into radially extending slots 70 disposed at each quadrant of upper turntable 26 to produce an initial coarse registration of the mold with stripping jaw 33. The sectionalized mold to be disassembled preferably is divided into four cylindrical arcuate sections 12a having quadrants of wheels 12b fixedly attached at opposite ends thereof (as is more fully explained in col-pending application Ser. No. 220,286 filed concurrently herewith in the name of F.W. Baumann et al. and assigned to the as signee of the present invention). After the bolts customarily utilized to mechanically secure the mold sections together have been removed manually, an automatic mold disassembly pushbutton 96 is depressed by the operator to place both mold disassembly stripping relay MDSR and mold disassembly table rotation stepping relay TRSR in a first position initiating automatic stripping of the mold sections from the cast. As can be seen from FIG. 6, the mold disassembly stepping relay initially opens valve 71 controlling the flow of hydraulic fluid to small diameter piston cylinder 48 to traverse carriage 43 to a position seating the arcuately shaped forward end 53 of support 52 against arbor 16. At the end of the forward traversal of the carriage, as observed by limit switch 50a (illustrated in FIG. 1), mold disassembly stepping relay is triggered to a second position to energize contact (2) and open valve 72 admit ting hydraulic fluid to piston cylinder 42 driving jaw 33 against the outer surface of mold l2 whereupon the mold disassembly stepping relay is moved to its third position (by a vane actuated switch 84 illustrated in FIG. I monitoring the traversal of jaw 33 relative to carraige 43) to energize contact (3) and open valve 73 admitting hydraulic fluid to piston cylinder 58 driving lock pins 41 through the aligned vertically extending apertures in the jaw and mold brackets to lock the jaw to the brackets. Desirably, the lower ends of lock pins 41 are tapered, as illustrated at 74, to force a vertical alignment between the vertically extending apertures in the jaw and mold brackets as the pins are driven therethrough by piston 59. When lock pins 4] reach the lower limit of the pin traversal, as observed by one of two limit switches 63 on bracket 64, the mold disassembly stepping relay is advanced to its fourth position to open valve 91 and expand plates 75 radially outward from arbor 16 to engage the inner periphery of cast 14. Upon engagement of the mold interior by plates 75 (as determined by pressure switch 92 in the hydraulic line of cylinder 88), the mold disassembly stepping relay is moved to its fifth position to energize contact (5) OF MDSR admitting hydraulic fluid to large diameter piston cylinder 42 in a direction retracting the large diameter piston from the mandrel to strip the engaged mold section of the cast. When the large diameter piston has reached the end of its desired traversal, as measured by limit switch 76, the stepping relay is moved to a sixth position activating small diameter piston 46 to withdraw carriage 43 and the disengaged mold section radially from mandrel 16 by an amount sufficient to retain the disengaged mold section upon upper turntable 26, Le, with pins 69 within slot 70 of the turntable. Upon a sensing of the desired carriage withdraw] by limit switch 50h (illustrated in FIG. 2), lock pins 41 are driven upward to disengage the jaw from the mold sec tion and the mold section is selt supporting on wheel quadrant 12b in a plane substantially parallel to the plane of he mold section upon the cast. Because the stripped mold section is released atop turntable 26,

subsequent rotations of the mold also rotate the stripped sections by the same amount to maintain a constant angular disposition between the cast and all mold sections.

After release of the mold section from jaw 33, the mold disassembly stepping relay is advanced by the second of limit switches 63 triggered by vanes 65 to an eighth position (i.e., energizing contact (8) of MDSR) admitting additional hydraulic fluid to small diameter piston cylinder 48 to drive carriage 43 to a restracted position (as illustrated in FIG. 1) to inhibit interference between the jaw and the stripped mold section during subsequent rotation of turntable 26. Plates 75 on mandrel 16 next are retracted by the mold disassembly stepping relay (now switched to a ninth position by limit switch 50c) to disengage the cast section from the stationary mandrel whereafter the mold disassembly stepping relay is advanced to its tenth position (by pressure switch 94 in the hydraulic line of arbor-expansion cylinder 88) requesting rotation of the turntable. The output signal on terminal of the mold disassembly is fed to the mold disassembly table rotation stepping relay TRSR to advance the table rotation stepping relay to its second position energizing contact (5) to rotate the cast and stripped mold section 180 thereby positioning a second section of the four sectioned mold adjacent stripping jaw 33.

Rotation of turntable 26 is effected by energization of drive motor 25 by the mold disassembly table rotation stepping relay and torque from the drive motor is transmitted to the turntable through clutch 77 by way of chain 78 linking the drive motor with sprocket 22 secured to the base of the main turntable. Energization of the motor is continued until upper turntable 26 is rotated approximately 180 whereupon cams 32a at the lower surface of the turntable engage limit switches 31b and 310 mounted on base 16 to advance table rotation stepping relay TRSR to a third position de-energizing drive motor 25 and disengaging clutch 77.

Although the cams underlying turntable 21 also engage selected limit switches after a 90 rotation of the turntable, such engagement does not terminate table rotation because table rotation stepping relay TRSR is programmed to accept stepping pulses only in a predetermined sequence. It should be realized, however, that successive 90 rotations of the turntable could be utilized to position the mood sections for stripping when the edges of adjacent mold sections are not interlocked in a manner requiring initial stripping of diametrically opposite mold sections.

Precise registration of the turntable with jaw 33 is achieved by hydraulically advancing wedge 80 into engagement with a V-notched plate 81 bolted to the underside of the main turntable (as illustrated in FIG. 8). Preferably, cylinder 95 driving wedge 80 is connected in parallel with relatively slow moaving piston cylinder 42 driving jaw 33 to register turntable 26 prior to each advancement of the stripping jaw. Thus, the relatively coarse registration produced electrically by controlling the energization of drive motor 25 is enhanced by the mechanical registration of the wedge and V-shaped plate subsequent to disengagement of the clutch driving the turntable.

With the turntable rotated 180 relative to the initial stripping position, mold disassembly stepping relay MDSR is again advanced to its first position by a reset signal from contact (6) of table rotation stepping relay TRSR to initiate stripping of the second mold section from the cast in the manner heretofore disclosed. As can be seen from FIG. 7b, after stripping of the second mold section from the cast, turntable 26 is rotated 90 for stripping a third mold section from the cast whereupon a turntable rotation of 180 is assomplished to permit the fourth and final section of the mold to be stripped from the cast under the control of the mold disassembly stepping relay. After stripping of all the mold sections from the cast, the mold sections are disposed within a substantially concentric plane relative to the cast and the cast is removed by lifting the cast vertically from the arbor.

Expansion of mandrel plates against the interior of the cast 14 preferably is accomplished utilizing the double tapered drive system illustrated in FIG. 9 and 10. Plates 75 have a curvature compatible with the internal diameter of the cast and are secured to orthogonally dispose jaw expanders 82 situated within slots 83 in central arbor 16. The radially inner edges of the jaw expanders are provided with a pair of lips 84 which are seated within slots 85 in cruciform centerpost 86. As can be seen in FIG. 9, slots 85 taper radially inward of the arbor with vertical span from turntable 26 to drive the jaw expanders in a radial direction as axially extending centerpost 86 is reciprocally driven by piston 87 secured thereto. Thus, upon admission of hydraulic fluid to piston cylinder 88, centerpost 86 is driven to the expanded jaw position illustrated in FIG. 9 while retraction of piston 87 into piston cylinder 88 causes the centerpost to be drawn vertically downward to retract the jaw expanders radially inward within slots 83. Because both the upper and the lower ends of the jaw expanders are secured within slots 85, any tendency for plates 75 to wobble is inhibited. Moreover, the double taper of centerpost 86 permits a more rapid radial expansion of the arbor plates than generally would otherwise be achievable utilizing a single tapered slot to control radial movement of the jaw expanders.

An important feature of the stripping machine of this invention is the ability of the machine to reassemble the mold sections subsequent to stripping of the sections from the cast. This is particularly important for large diameter casts, e.g., 440 motor frames, where the individual mold sections may weigh as much as 800 pounds. Reassembly of the mold also is performed substantially automatically utilizing a five position mold assembly stepping relay MASR to regulate the operation of the pistons controlling the radial position of the stripping jaw relative to arbor l6 and an eight position mold assembly table rotation stepping relay MATR to control the operation of turntable drive motor 25 (as is illustrated in FIGS. 11 and 12). To initiate mold reassembly, the operator triggers mold assembly stepping relay to a first position to drive small diameter piston 46 in a direction moving carriage 43 towrd the stripped mold sections to seat forward end 53 of the carriage in contact with arbor 16. The mold assembly stepping relay then is moved to a second position by limit switch 50a monitoring the position of the carriage whereupon hydraulic fluid is admitted to large diameter piston cylinder 42 to drive jaw 33 toward arbor 16 thereby pushing the mold section to approximately the original position of the section upon the cast. At the end of the traversa] for the jaw, the mold assembly stepping relay is actuated by-limit switch 84 to a third position to retract the jaw from the mold section whereupon the mold assembly stepping relay is moved to a fourth position (by limit switch 76) retracting small diameter piston 46 into piston cylinder 48 to move carriage 43 from arbor 16 by a predetermined distance controlled by limit switch 50b (illustrated in FIG. 2). The mold assembly stepping relay then is advanced by limit switch 50b to a fifth hposition triggering mold assembly table rotation stepping relay MATR to a second position and rotating turntable 26 by 180 thereby positioning a second stripped mold section adjacent jaw 33. The sequential operation of the mold assembly stepping relay then is again initiated by a stepping pulse from limit switches 31 energizing terminal 6 of table rotation stepping relay MATR to drive the mold section toward the arbor in a manner heretofore described whereupon the table is rotated 270 to position a third mold section confronting jaw 33 for subsequent pushing to the original mold position upon the cast. After all the mold sections have been pushed to their original positions, bolts (not shown) are manually inserted through aligned apertures at the mold section edges to reassemble the mold permitting the mold to be removed from the mandrel for casting of a subsequent motor frame.

What we claim as new and desire to secure by Letters Patent of the United States of America:

1. A machine for stripping a sectionalized mold from a cylindrically shaped cast, said machine comprising:

a. an arbor fixedly secured to a stationary base at an attitude to extend axially into a cylindrically shaped cast,

b. at least one mold section clamping means disposed at a radially removed attitude relative to said arbor,

c. means for advancing said clamping means toward said arbor, said clamping means being operable to fixedly engage at least one section of said mold disposed about said arbor,

d. means for retracting said clamping means radially from said arbor to apply a force to the section of said mold fixedly engaged therewith in a direction perpendicular to the axis of said cylindrical cast to strip said engaged mold section from said cast,

e. means for maintaining said stripped mold sections at a radially outward location relative to said cylindrically shaped cast in a plane substantially parallel to the plane of said section upon said cast until all said mold sections have been stripped from said cast, and

f. means for radially moving said clamping means toward said arbor subsequent to removal of said cast from the interior of said stripped mold sections to apply force to individual sections of said mold in a direction opposite said stripping force to was semble said mold sections into a cylindrical structure.

2. A machine for stripping a sectionalized mold from a cylindrically shaped cast according to claim 1 further including means for rotating said stripped mold section and said mold and attached sections relative to said clamping means for sequentially registering subsequent mold sections with said clamping means, said rotating means maintaining a constant angular disposition be tween said stripped mold sections and said cast.

3. A machine for stripping a sectionalized mold from a cylindrically shaped cast section, said machine comprising:

a. a vertically extending arbor,

b. a turntable disposed axially about the lower periphery of said arbor and rotatable relative to said arbor,

0. means for rotating said turntable about said arbor in predetermined angular segments,

d. means for contracting said arbor prior to rotation of said turntable to disengage the inner sidewall of a cast axially mounted thereon from said arbor to permit rotation of said cast upon said turntable independently of said arbor,

e. clamping means disposed adjacent said arbor for fixedly engaging individual sections of said mold upon advancement of said clamping means into contact with said sectionalized mold,

f. means for expanding said arbor to engage the inner periphery of said cast, and

g. means for moving said clamping means in a direction perpendicular to the axis of said arbor to strip said mold section from said cast.

4. A machine for stripping a sectionalized mold from a cylindrically shaped cast section according to claim 3 whereinsaid means for expanding and contracting said arbor include:

a. a first member having slots therein tapering in a radial direction,

b. a second member having lips engaged in said slots at a plurality of axially displaced locations, and

c. means for moving said first member relative to said second member to produce radial expansion of said arbor.

5. A machine for stripping a sectionalized mold from a cylindrically shaped cast section according to claim 3 further including means for disengaging said rotating means from said turntable upon rotation of said turntable a predetermined angular span and registration means disposed upon said turntable for mechanically positioning said turntable relative to said stripping means.

6. A machine for stripping a sectionalized mold from a cylindrically shaped cast section according to claim 5 wherein said means for moving said clamping means toward said arbor include at leasttwo hydraulically driven pistons having diverse diameters, said small diameter piston driving a carriage bearing said large diameter piston to a predetermined distance from said mold section to be stripped and means for advancing said large diameter piston from said carriage for engagement of said clamping means with said mold section.

* I l lj

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3866661 *Feb 26, 1974Feb 18, 1975Gen ElectricHorizontal centrifugal casting method
US4185681 *Jun 22, 1978Jan 29, 1980Conveyersmith, Inc.Ceramic knock-off apparatus for removing ceramic from investment casting molds
US4203483 *Jan 10, 1979May 20, 1980General Electric CompanyMethod of positioning components of a centrifugal casting machine for a mold stripping operation
Classifications
U.S. Classification164/401, 164/131
International ClassificationB22C25/00, B22D29/04, B22D13/10
Cooperative ClassificationB22D13/10, B22D29/04
European ClassificationB22D13/10, B22D29/04