US2260462A - Die for pressure casting - Google Patents

Description

Oct. 28, 1941. T. c. KoRsMo 2,260,462

DIEFORPRESSURE CASTING Filed April 9, 1941 4 Sheets-Sheet l 1 no w e n a n N 1 1 o m u. .wd Pb N;

' 'T l b Om M Tr mw u m attorneys 28, 19 1. T. c. KQRSMO 2,260,462

DIE FOR PRESSURE CASTING Filed April 9, 1941 4 Sheets-Sheet 2 ZSnventor C(ttomegs Oct. 28, 1941. 'r. c. KORSMO 2,260,462

DIE FOR PRESSURE'CASTING Filed AprilS, 1941 4 Sheets-Sheet 3 Snoentor 8 56 Umpmeamw attornegs Oct. 28, 194.1. 'r. 'c. KORSMO 2,260,462

- DIE FOR PRESSURE'CASIING Filed April 9, 1941 @Sheets-Sheet 4 6O. Zhwentor (Ittornegs cast under heavy pressure. rate positive positioning. of all die parts, par- Patented Oct. 28, 1941 UNITED STATES PATENT OFFICE 2,260,462 nm FOR PRESSURE oAs'rma Torbjorn C. Korsmo, Madison, Wis., assignor to Madison-Kipp Corporation, Madison,

Wis., a

corporation of Wisconsin Application April 9, 1941, Serial No. 387,722

18 Claims. (Cl. 22-151) This invention relates to dies for die casting machines and particularly to the form and mounting therein of a contractible core and themode of operating and' manipulating such core during and after opening of the die and during closing of the die. The invention, though not necessarily limited thereto, was developed for, and has demonstrated particular utility in connection with, the casting of aluminum alloy pistons.

Simply for convenience the invention will be described as so embodied. The invention is especially applicable wherever the internal form of a cylindrical or cup-shaped casting requires the use of a contractible core, and is particularly usefulwhen the length of the core is substantial, for example, nearly as long as the hollow casting.

To secure good grain, alloy pistons should be This requires accuble section comprise the complete main core or main core assembly.

As the die initially opens, the main core assem-' bly moves with the movable die half on which it is mounted; so that the casting is strippedfrom the fixed die half and from any core fixed thereto. During this phase a die component which defines the piston head is also retracted. In the next phase of opening movement the central section .of the main core, which is supported by a slidable carriage on the movable die half, is completely withdrawn from the casting, thereby stripping the other sections of the main core= from the casting because of the converging form of the core guideways, but leaving these core sections loose within the casting. In the final phase of opening movement any remaining small cores are withdrawn, after which the ejector mechanism ejects the casting and the contained core sections from the movable,die half.

When the die is fully 'open the central section of the main core, which is permanently mounted .for the purpose on a carrier pivotally supported to 'the o 1 drawings, in which:

Fig. 1 is a face view (elevation) of the movable outwardly away from the inner face of the movable die-half and preferably entirely from between the die halves. After this the other parts of the main core are retrieved from the ejected casting and reapplied to the guideways on the central core section while the latter core section is removed from between the die halves and is thus in a position in which it is fully accessible rator to replace the retrieved core sections the con without the die parts or machine parts interfering with this operation. The assembled main core is then manually swung back to position between the die halves, whereupon closure of the die will automatically return all die parts and cores to normal casting position.

A commercial embodiment of the invention, a die structure for casting trunk pistons for intemal combustion engines, will now be described in detail with reference to the accompanying die half and all parts carried thereby, the parts being in the positions they assume when the die is closed. The molten metal supply well is shown in section.

Fig. 2 is a section of the die in closed position, the plane of section beingindicated by the. line 2--2 in Fig. 1.

Fig. 3 is a plan view of the die carrying parts 'of a die casting 1 machine with the improved die mounted therein, the parts being shown in dieclosed position. The position of the die cavity and of the cores is indicated in-broken lnes.

Fig. 4 is a similar view but illustrating the completely open position of the die, the central main core section being shown swung from between the die halves for reassembly .of the other retrieved core parts therewith.

' Fig. 5 is a perspective view of the main'core.

carriage and the main core carrier which'is hinged thereto. Only the central withdrawable sectionof the main coreis shown. The parts are positioned as they are after the carrier is swung outward from between the die parts, as appears in Fig. 4.

. Fig. 6 is an elevation showing the rack face of the core carriage and the lugs thereof between which the carrier is pivoted.

Fig. '7 is a transverse section of the main core assembly indicating the form of the guides which interconnect thethreecomponents of the core.

I section showing the core carriage fully retracted.

by 'the movable die half. may be'manually swung Fig. 8 is a view partly in plan and partly in In this position the central main core section has been completely withdrawn from the die 'upright or hot plate cavity and the cavity-forming inserts and hence from the castingand the loose main core sections therein, following which the latter were ejected, and the carrier may now be swung out to the position of Figs. 4 and 5. The carrier is, however, shown swungvout. I

Fig. 9 is a vertical central section through the 'metal pressure chamber in the closed .die and the registering metal well, the section being taken at right angles'to Fig.1.

Referring first to Figs. ii -and 4, bed portion ID as it appears before being so of. the machine frame is provided with the rigid theflxed die half or die section, generally indi- Hot plate carries I The parts so far described are simply familiar components of known die casting machines, and

- no novelty is here claimed for any. of them.

'Moreover, various known equivalents may be substituted so far as the present invention is concerned. 1

Refer now to Figs. 1 and 2.

- The fixed die half or section l2 comprises a 'main body l2 and two fixed inserts, namely the cated at l'2,*and is connected by two guide rods tion on rods |3,,to open and close the die, is a carriage l5 which is actuated by a hydraulic ram I! carried by head H. The ends of carriage l5 are connected by two tie rods It to the remote end of :the ram (not shown). Threaded studs l1 and I8, carried by head l4, are adjustable stops which during opening of the die first arrest the movable core actuator plate I! by direct engagement therewith and thus shortly thereafter cause |,31-.,with the. uprlFht or head II which also is a axed part of the frame. Guided for reciprocaengagement of the movable ejector plate 2| with plate l9 so as to arrest plate 2| also. Thus these two plates, which are slidably carried by the movable die .half or section generally indicated at 22, are operated serially by stops II, It as the movable :die half moves in die-opening direction. As the opening'mo'vement is completed, movable die half 22 moves into contact with the arreste plates l9 and 2|, as appears in Fig. 4.

of the die (Fig. 4), and are ment fixed die half I2 to their original normal and thereby restore plates 2| and I!) to again closes.

Movable die half 22 is supported by two brackets 23 projecting to the'left (Figs. 3 and 4) from the ends of carriage |3. Movable die half 22- slidably supports ejector plate 2| by means of the ejector pins 24 and the return pin 2|' secured to'the plate, and the core actuator-plate It by i means of the toothed core-actuating-plunger' 25' andthe return pin l9 secured to plate l9 and extending through suitable 1 1 Figs. 1 and 2).

openings in plate 2| (see plates i9 and 2| (Fig. 3) are. spaced To efl'ect the serial operation 01' referred to above, these plates in normal die-closed position fromeach other and also from movable die half 22. Slidable return pins 2| and I9 for plates 2| and i9 extend through movable die half 22 to the parting line of the die when the die is closed (Figs. 2 and 3), are projected from the face of die half 22 actuated near the end of the opening movement returned by engagepositi fixed die half insert 3| which has a portion 3| gforming half of the die cavity 43 (Fig. 2), and the insert 29 which forms half of the pressure chamber in which the casting material (molten metal in the particular case described) is subjected to pressure to force it into the die cavity; Themov-- able die half or section22, similarly to the fixed die half, comprises a main body 22' and two inserts, namely, the movable die half insert 32 which has a portion 32' forming the complemental half of die cavity 40, and the insert 30' which forms the complemental half of the preswhen plates 2| and I9 are their original positions of Fig. 3 when the die 2n and 28, fixed on movable die half 22, have their shanks extending freely through suitable openings in plates l9 and'2l, respectively, so' that their heads accurately limit the return of these 'platesiand connected parts to normal position.

Opening 26' in plate I! accommodates the head 1 of stud 26 during relative movements of' the plate and, the stud.

. As shown in Fig. 2, headed studs 6 A combination bar 21 extends between upright and I4 to which it is releasably. coni nected by socketbolts 28. The combination bar 1 is simply an interchangeable cam carrying mem-' ber. It carries cams used to 'operatedie components, In this case it carries a cam which actuates the main core. I

sure chamber.

Die half inserts 3|, 32' are complemental, except thatthe portion of the closed die which forms the head of the piston casting, comprises the axially retractable member 33 which is connected by neck 34 with the carrier 35. Carrier 35 I is mounted in movable die half 22 for reciprocation in the direction of the piston axis. For this purposecarriage 35'is slidably arranged in an open-ended channel 33 in die member 22' with which it has slidabie undercut tongue-and-groove connections at 35. An angle pin fixed in stationary die half I2 and extending obliquely through a slot 36' in carrier 35 serves to'withdrawv die member 33 as the die'opens. This motion commences almost immediately after opening motion starts.

Flxed-die-half insert 3| carries a fixed core 3'! which forms the wrist pin opening in the wrist pin boss on one side of the piston casting.

Aligned with .core 31 and axially'movable in a suitable passage in die-half insert 32 in movable die half 22 is a companion core 38 for the open ing in the wrist pin boss on the other side of the piston. Core 38 is connected to'andactuated by toothed slide 39 guided in movable die half 22.

A motion-transmitting pinion 4| joumaled in die half 22 engages the teeth on plunger 25. Thus, near the end of the movement of die half 22 in an opening direction, arrest of plate l9 by stops ber 22' andhas slidable undercut tongue-andgroove connections therewith-formed by tongues orflanges 50 on carriage 42 and coa'cting undercut grooves 50' in die member 22'. Carriage 42 is channel or U'-shaped in transverse section (see- Fig. 5) and the outer face of its base-43 is toothed a indicated at 43. These teeth mesh with elongated pinion 44 journaled in movable die part 22'. An arm 44' fast to pinion 44 carries a roller 45 confined in the Y-shaped cam slot 21' on the lower face of combination bar 21. The parts are so arranged that complete opening of the die will turn pinion 44 about.165, thereby sliding core carriage outward a'distance such that the central main core section is moved completely from a ed-102" between die half inserts II and 32 as indicated in F18. 8..

Base 43 of core carriage (Fig. 6) to provide perforated side wall extensions or lugs 48'. Between these lugs the outer end of the main core carrier 48 is located and secured by hinge pin 48', whereby carrier 48 is mounted for manual swinging movement on carriage v42.

Normally carrier 48 is located 'in channel shaped carriage 42 between walls 48 and against base 43 of the latter, with the inner ends of the carriage and the carrier flush with each other and abutting against side faces 8! and 82 of die inserts 3|, 32 (as shownin Fig. 2) to aid in accurately and firmly locating the main core in die cavity 48. A recess 48 in fixed die half part 12 receives a projecting portion 58 of core carrier 48 42, which latter has .upper and lower side walls 48. is notched at 41 i rier 48 and outside the die cavity proper, the base and provides an inclined shoulder 48' engaging a slmilarlyj inclined shoulder 88 on carrier portion 58. This arrangement also aids in accurately and firmly locating the main core in the die as its is closed and the abutting shoulders relieve pin 48' of outward stress of carrier 48 thereon during the casting operation.

Core carriage 42 has a partition 5| which is normally located in a slot 52 in core carrier 48. Partition 5| and slot 52 provide one pair of abutting shoulders '58, 58 and a second pair of abutting shoulders 1|, 12. The interengagement of shoulders 58 and 68 relieves pin 48 of stress has the die closes and carriage 42 moves the main core firmly into casting position in the die, and also aids in relieving pin 48 of stress during shooting of the casting. Engagement of shoulders 1| and 12 relieves pin 48' of stress when the die opens and carriage 42 moves outward to withdraw the central main core section. When the die is closed, vertically aligned notch 53 in core carrier 48 and notch 54 in core carriage 42 receive the lower end of the threaded core positioning and locking bolt or dowel pin (Fig. I) which is mounted in die member 22' and projects into channel 42' thereof. Thus, pin 55 normally locks core on pin 48' and the main core is rigidly held in place on movable die half 22, thereby assuring pulling of the casting from the fixed die half 12 and core 31 by the main core in the initial open? ing motion of the movable die half. When the die is wide open and hence outward sliding movement of carriage 42 and carrier-'48 has freed their notches 53 and 54 from locking pin 55, main core carrier 48 may be swung out by the operator from between die halves l2 and 2-2 and into'the position shown in Figs. 4 and 5 by means of handle 55. v

Core carrier 48 permanently supports on its end the central. section 51 of themain core. Core section 51 normally'removably supports thereon the complemental sections 58 and 61 of the main core by means of slidable dove-tail guideconnections between the core sections. The abuttin plane faces" and 14 of sections 51 and 58, respectively, and the abutting plane faces 15 and 15 of sections 51 and 51, respectively, are arranged at a slight angle lengthwise of the core (Figs. 2 and '7) so that central core section 51 is tapered toward its outer end. Faces 13 and 15 of section 51 have dove-tail guide grooves 11, and

face 14 of section 58 and face 15 of section Bl have dove-tail guides or tongues 18 which slidably interfit with grooves 11. The abutting surfaces, of these tongues and grooves, including the undercut side walls of grooves 11 and the undercarrier 48 against swinging indicated at 82. Adjacent carrier 48 this cone is completely surrounded and closely embraced by 'the semi-circular tapered portions 18 and 88 of die half inserts 3|, and 32. Thus, these complemental tapered portions form an annular tapered shoulder which engages tapered base 52 of the core to maintain removable core sections 58 and 81 in position with their inner ends incontact with-carrier 48 and to accurately and firmly hold the three-section core assembly in place in the die cavity. As the die closes, side faces'8l and 82 of die inserts 3| and 32 act as stops to limit inward movement of carriage 42 and carrier 48.- At the same time, tapered portion 88 of die insert 32 acts as a stop limiting the inward movement of core sections 51 and 58 by engaging their inclined base surfaces and thus accurately positioning these parts. Near the end of the inward movement of carriage 42 and carrier 48 notches 53' and 54 in these members engage dowel pin 55, thus further aiding in accurately locating the main core in the die and locking carrier 48 against swinging, as stated.

Die inserts 3| and 32 have an annular groove 58. and an annular rib 53 cooperating with tapered base 52 of the main core to form an annular gate or chamber'58" and an annular ingate 83' both of which surround base 62. Thus metal passing from gate 58' through ingate 63 a is fed to die cavity 48 arounda circle corresponding to what becomes the margin of the piston skirt. The sprue 64 connects gate 58 with open-bottom pressure chamber 85. When the die is closed,.the pressure chamber registers with metal-well 88 supported by machine bed l8 and containing a lowered forcing plunger 51 (Fig,s. 1 and 9), the illustrated machine being constructed according to Schultz' Patent No. 2,183,438, issued December28, 1937. A proper charge of metal having been placedin well '55 while the die is open and the die then closed, plunger 51 rises through well 55 and into pres-,

surechamber 85 to transfer the'metal from the well'into the pressure chamber and then force it under high pressure intoYannular-gate 58' and thence into die cavity 48. toform the piston casting. l

, Operation The general operationof the device has been explained in connection with the description of.

latter has some of the aspects of a core but is, not strictly a core. The effect is to withdraw. a

member 33 and to pull the casting out of the fixed die half 12 and off the fixed core 31. When the parts reach a position in which the casting in movable die half 22 is clear of core 31, cam 21 starts to rotate pinion 44 and move core carriage cut edges of tongues 18, converge in conformity 4 l2 outward. The effect ofthis is to withdraw main core part 51, thus contracting main core parts 59 and 6|, which are thus stripped from the casting by core part 51 but left in loose condition of the casting and the core parts 59 and 6| therein from movable die half 22. Core 38 is withdrawn next as the result of collision of plate It with stops l1 and I8. Finally, ejector pins 24 are actuated as the result of arrest of plate 2| by plate l9 so that the casting, with main core sections 59 and GI still in it, drops from movable die half 22. The timing of the movementsof the parts as just defined may be varied if found desirable, but withdrawal movement of main core part 51 should start before withdrawal of core 38 commences. I

The machinen'ow stops with the die in the full-open position of Fig. 4, whereupon carrier 48 with its permanent core part 51 is swung outward by the operator to the position shown in 1 ,Fig. 4 by means ofhandle 58. Main core parts 59 and 6| are now recovered from-the interior of l the casting by the operator and slidably reassem- 1 bled intheir normal positions on central core part 51 as shown in'Fig. 2. Since this reassembly takes place with core part 51 in the position of 1 Fig. 4 where it isfuliy accessible to the operator 5 obviously, this is an important aid in reassembling the. core parts properly and with facility. Following this operation, the operator actuates handle 56 to swing carrier 48 with its reassembled main core back between die sectiom l2 and 22 and into the position of the parts shown in Fig. 8-.

After another metal charge is placed in well 86,

44 by cam 21' slides carriage l2, carrier 48 and the assembled main core inwardly from the position of Fig. 8 and into normal casting position relatively to movable die half 22 (see Fig. 2) before the die completely closes, so as to prevent interference by fixed core with the re-positioning of the main ,core. Member 33 is restored to casting position by pin 36. Near the end of the closing movement of die half 22, but subsequent- It will be understood that the invention can be than the particular one briefly described herein.

; It is also obvious that minor modifications in the arrangement of the main core can be made within the scope of the inventionfand of course'the form 1 of this core and of the die h'alve's is a function of 1 the casting to be produced. The idea of feeding i the die cavity from an annular gate surroundingthe base of the main core-where the core-is of sectional construction and is'centered and con- Iiined by the die halves, is believed to be an important factor in the attainment of sound castings.

'What is claimed is: multi-section sep- -1. The combination in a arable casting die of a pair of die sections adapted for relative movement in a definite path to Openand close the die, the opposed faces of said die sections having portions coacting to form a casting cavity when the die is closed; and a core assembly. comprising a permanent core member and at least one removable core member slidably mounted on said permanent member, carried by one of said die sections and located in casting po- 1 ram I5 is "operated to close the die. Such clo- 1 sure automatically returns all die parts and cores 1 to the normal casting position of Figs. 2 and 3 a by the means already described, in readiness to shoot the next casting. During the closing move-' ment of die half 22, reverse operation of pinion sition in the die cavity when the die is closed. the permanent core member being pivotally mounted on said,die section and also mounted thereon for sliding movement, during opening of the die, sufficient at least to completely withdraw the permanent core member from a casting formed in the die and to separate the permanent core member from the removable core member which is retained in the casting, said permanent core member being swingable away from its supporting die section following said withdrawal to render it fully accessible to an operator for slidably mounting at least one removable core member thereon-to-form a core-assembly, said assembly being swingable towards said diesection while the'die is open and then slidabie thereon to position the assembly in the die cavity as the die is closed, the permanent core memberbeing adapted for automatic actuation during opening and closing of the die to effect said sliding. movements thereof.

'2. The combination in a muiti-section sep-' arable casting die as claimed in claim 1 wherein the permanent core member is pivotally mounted on a core carriage carried by the core supporting die section and having sliding interlocked connection therewith for sliding movement on said die section during opening andclosing of the die to permit said sliding movements of the permanent core member.

3. The combination'in a multi-section separable casting die as claimed in claim 1, wherein the permanent core member is rigidly supported on a core carrier whichfis pivotally mounted on a core carriage carried by the core supporting die section and having sliding interlocking connection therewith for sliding movement on said die section during opening and vclosing of the die to permit .said sliding and swinging movements of the permanent core member.

4. The combination in a multi-section separable casting die as claimed in claim 1 wherein ing the first part ofthe'opening movement of the die. said withdrawing movement ofthe permanent core member serving automatically to .release the lockingme'ansas opening movement of the die continues.

5. The combination in a multi-section separable casting die as claimed in claim 1 wherein 4 releasable and restorable locking means are provided to prevent said swingingmovement of the permanent core member away'from its supporting die section during the first part of the opening movement of the die, said withdrawing move ment of the permanent core member' serving automatically to release the locking means as opening movement of the die continues. and said sliding movementto position the core assembly in the die cavity, as the die is closed. serving auto,- matically to restore the locking means. '6. The combination in a multi-section se'pa rable casting die as claimed in claim 1 wherein means are provided for relieving stress on said rable casting die as claimed in claim 1. wherein the permanent core member is rigidly supported on a core carrier which is pivotally mounted on a core carriage carried by the core supporting die section and having sliding interlocked con-. i

nection therewith for sliding movement on said die section during opening and closing of the die to permit said sliding and swinging movements or the permanent core member; and wherein re-- leasable and restorable locking means are provided to prevent saidswinging movement of the core carrier during the first part of the die open-v ing movement and during the later part of the die closing movement, said retracting movement section and having sliding interlocked connection therewith for sliding movement on said"die-sec-- .tion during opening and closing of the die to permit said sliding and swinging'movements of" the permanent core member; and wherein abutting surfaces are provided on the core carrierand the core carriage for relieving stress on said pivotal connection between the core carrier and the core carriage.

12. The combination in a multi-section separable casting die as claimed in claim 1 wherein the of the permanent core member serving to release the locking means and the return of the permanent core member into casting position in the die serving to restore the locking means.

8. The combination in a multi-section separable casting die as claimed in claim 1 wherein the permanent core member is rigidly supported on a core carrier which is pivotally mounted on a core carriage carried by the core supporting die section and having s'liding interlocked connection there with for sliding movement on said die section during opening and closing of the die to permit said sliding and swinging movements of the permanent core member; and wherein releasable and restorable locking means are provided to prevent said swinging movement of the core carrier during the first part of the die opening movement and during the later part of theidle closing movement, said retracting movement or the permanent core member serving to release the locking means and the return of the permanent core memberinto casting position in the die serving to restore the locking means,' said locking means comprising a separable,pin-and-slot connection between the more carrier and the core carrying die se'ctionj e 9. The combination in a multi-section separable casting die as claimed in claim 1 wherein the permanent core member is rigidly supported on a core carrier which is pivotally mounted on a core carriage carried by the core supporting die section and having "sliding interlocked connec-. tion therewith for sliding movement on said die section during opening and closing of the die to permit said sliding and swinging movements of the permanent core member; and wherein guide means are provided on the core supporting die section for coaction with said core carrier to guide the core assembly and accurately position it in the die cavity during inward sliding movement of the core assembly, the core carrier and the core carriage as the die closes.

10. The combination in a multi-section separa-.

ble casting die asiclaimed in claim 1 wherein means are provided for withdrawing the permanent core member as the die is opened, said means forming a slidable part of said core supporting die section on which the permanent core member is pivotally mounted; and wherein means are provided to relieve stress on said pivotal connection during said withdrawal movement of the permanent core member.

11. The combination in a multi-section separable casting die as claimed in claim 1 wherein the permanent core member is rigidly supported on a core carrier which is pivotally mounted on a core carriage carried bythe coresupporting die permanent core member is rigidly supported on o a core carrier which is pivotally mounted on a core carriage carried by the core supporting diev section and having sliding interlocked connection therewith for sliding movement on said die section during opening and closing or the die to permit said slidingand swinging movements of the permanent core member; and wherein said core carrier is formed with a recess and the core carriage has a lug adapted to be snugly located in said recess for relieving stress on said pivotal connection between the core carrier and the core carriage.

13. The combination in a multi-section separable casting die of a fixed die section; a die section adapted for movement towards and from the fixed die section to close and open the die, the

manent core member and at least a pair of opposed removable core members slidably mounted on said permanent member, carried by said mov.-

able die section'and located in casting position in the die cavity when the die is closed, the permanent core member being pivotally mounted on the movable die section and also mounted thereon for sliding. movement, during opening or the die, suflicient at least to withdraw the permanent core member completely from a casting formed in the die and completely from between said removable core members to separate the permanent core member from the removable core members which are retained in the casting, said permanent core member being manually swing-,

able away from the movable die section following said withdrawal to render it fully accessible to an operator for slidably mounting at least a pair of removable core members thereon to form t a core assembly, said assembly being manually swingable towards said movable die section while the die is open and slidable thereon to position the assembly in the die cavity as the die is closed, the permanent core member being adaptedfor automatic actuation during opening and closing of the die to effect said sliding movements thereof.

14.- The combination as claimed in claim 13 wherein operating means are carried by the movable die section for imparting said sliding movements to the permanent core. member during opening and closing movements of the die, said operating means being adapted for automatic actuation during said movements of the die by means on a casting machine in which the die 7 may be mounted.

15. The combination as claimed in claim 13 wherein'the permanent core member is arranged to swing in a substantially horizontal direction i118 die of a flxed die section; a die section adapted for movement towards and from said fixed die section to close and open the die, the

opposed faces oi. said -die sections having por- 'manently mounted on the core carrier anda pair of opposed removable core members slidably mounted on said permanent-core member, located in casting position in the'die cavity'when the die 'is closed, the carriage together with the core carrier and the permanent core member being slidable as a unit on the fixed die halt,

during opening of the die,v suflicient'at least to withdraw the permanent core member completely from a casting formed in the die and comthe core carrier which latter is arrangedjor swinging movement completely from between the open die sections; and the permanent core pletely from between saidren ovable core mem 'bers' toseparate the-permanent core member from the removable core members which latter are retained in thecasting, said core carrier and the permanent core member being manually swingable away from the movable die section following said withdrawal to render the permanent core member and its carrier fully accessible to an operator for slidably mounting a" pair of.

removable core members on the permanent core, member to form a core assembly. said assembly and the core carrier being manually swingable towards the movable die section while the die is open and then s'lidable as a unit-with the core carriage on said-die half to accuratelyand se curely position the core assembly in the die cavity as the die-is closed, the core carriage being adapted for automatic actuation during opening and closing of the die to effect said sliding move ments thereoi.

17. The combination in a'multi-section sepamember and the removable core members are provided with slidable interlocking tongue-and groove connections with each other and said connections converge-towards the outer end of the permanent core member, so that withdrawal of the latter core member contracts the other core members to loosen them from the casting.

18. I'he combination in a multi-section separable casting die of a plurality of die sections adapted for relative movement to open and close the die; the opposed-faces of said die'sectio'ns having portions coacting to form a casting cavity, other portions coacting to form an annular groove and still other portions coacting to form an annulartapered shoulder, when the die is closed; and a core assembly'having a tapered base portion and comprising a permanent central core member andaa pair of opposed removable core members mounted on said permanent '"core member by means of slidable interlocking tongue-and-grooveconnections, said core as sembly being slidably carried by one of said die sections for movement into casting position in the die .cavity as the die isclos'ed and'in which position'sa id core assembly cooperates with said cavity-forming portions of the die sections to rable casting die as claimed in claim 16 wherein the permanent core member during opening and closing movements 01' the die, said operating means beingradapted -for automatic actuation during said movements of the die by means 'on a casting machine in which the die may be mount- 1 ed; wherein a handle is provided-tor swinging rack-and-pinion means are provided on the V movable die half for imparting said sliding move: ments to the core carriage, the core carrier and provide an. annular casting cavity space, said tapered base portion of the core assembly coacts with said annular grooveto form an annular gate and an annular ingate connecting said gate and said annular casting cavity space, and said tapered base portion of the core assembly engages said annular tapered shoulder to accurately, locate theassembly in the die cavity and prevent movement of the'movable core members on the permanent co'remember, the permanent .core member being slidable on itssupporting die section, during opening of the die, suflie cient' at least to withdraw the permanent core member completely from a casting formed in the die and completely from between said removable core members to separate the permanent core member from the removable core members which are retained in the casting, said permanent core member being adapted for automatic actuation during opening'and closing of the die to efl'ect said sliding movements thereof,

TORBJORN c. KORSMO.

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