US2287524A - Molding apparatus - Google Patents

Description

June23, 1942Q S. W. JACKSON MOLDING APPARATUS Filed Feb. 26, 1941 3 ShLeS-Sheel l June 23, 1942. s. W.4 JACKSON MOLDING APPARATUS Filed Feb. 26, 1941 3 Sheets-Shaml 2 June 23, 1942. W JACKSQN MOLDING APPARATUS Filed Feb. 26, 1941 5 SheetsvSheet 5 9 OO 7 Z 8 4 6 4 5 oo 5 4 INVENTOR ,Sidney TV; Jackson BY wr/ 1 76 he ATTORNEYS Patented June 23, 1942 Y MOLDING APPARATUS Sidney W. Jackson', Parma, Ohio, asslgnor to The- Permold Company, Cleveland, Ollio, a corporation of Ohio Application February 26, 1941, Serial No. 380,695v

17 Claims.

This invention relates to molding apparatus, and more particularly to apparatus of this character for casting cup shaped articles such as pistons for internal combustion engines and the like.

Pistons are preferably made from light metals,

such as aluminum alloys, `and it is desirable for various reasons to cast the pistons in permanent molds. Such molds, when utilized for making a great number of pistons, are capable of `producing the pistons with great uniformity and at a low unit cost. Additionally, the physical properties ofv the pistons are improved so that the pistons are stronger and wear better than pistons made in sand molds.

'Ihe internal structure of aluminum alloy pistons and the like and pistons formed primarily of aluminum alloy with ferrous metal inserts therein, may have widely variant internal structures. Accordingly, the cores for casting such pistons may have numerous shapes or configurations. Most light metal or aluminum alloy pistons do have lateral extensions or boss'es on the inside of the skirt to receivethe connectingv rod pins. Frequently, the pistons have other lateral formations on the inside of the skirt, such as ribs and bosses, provided to strengthen or balance the structure. These lateral extensions interiorally of the piston, being formed by the core, require that the latter be contracted or collapsed and withdrawn in sections. Usually the composite or sectional core of a piston mold includes a central section and lateral or outer sections. 'Ifhe practice is to rst withdraw the central sections from a casting, after which the outer or lateral sections are moved serially or simultaneously into the space vacated by the central section so as to clear the projections on the inside of the piston skirt and are then withdrawn axially from the piston casting., This withdrawal of the several core .sections and Athe subsequent reassembling thereof to prepare the apparatus for the next casting operation requires considerable time and bination with a mechanism for automatically withdrawing the core sections rapidly from a piston casting and for rapidly reassembling the sections in readiness for a succeeding casting operation.

Another object is to provide a sectional core for a permanent mold and actuating mechanism therefor which withdraws the several sections of the core from a casting over predetermined paths so as to avoid engagement between the core sections and casting during the withdrawal of the core. f

Another object is to provide actuating mechanlsm for a multi-part core which is so interconnected that by the movement of a single powerdriven actuating meansall'or the core sections can be moved into and out of casting position. More specifically, the -invention aims to provide a sectional core for a piston mold in which a plurality of the core sections are mounted for tilting movement so as to clear the same from dexterity on the part of the operator if performed the lateral projections on the inside of the piston, and are -so interconnected by the operating mechanism for the core that they can be successively moved into the center of the piston by a single power means.

Numerous structural improvements are incorporated in the apparatus, including: means for pivctally mounting the outer sections of the core so that the core movementis guided by pivots and confined to predetermined paths; an arrangement of counterweights for balancing the core sections and for normally holding the core sections in assembled positions; the combination of pivotally mounted support members and a cam plate'for guiding the movement of one of the core sections; and a lost motion connection in-v Fig. 2 is an end elevational view, with parts re-` moved, of the apparatus shown in Fig. 1;

Fig. 3 is a sectional detail taken substantially on the line 3-3 of Fig. 1;

Fig. 4 is a fragmentary elevational view of the apparatus shown in Fig. 1 with the mold sections l! drawn apart to expose the casting;

Fig. 5 is a vertical sectional view on an enlarged scale through the center of the apparatus illustrated in the preceding gures and showing the central core section removed from the casting and one of the outer core sections tilted into the space previously occupied by the central section;

Fig. 6 is a sectional detail taken substantially on the line 6-6 of Fig. 4; .i

Fig. 7 is a vertical sectional view on an enlarged scale and similar to Fig. 5, illustrating a subsequent stage in the removal of the sectional core in which one of the outer` sections has been withdrawn from the casting and the other outer core section has been tilted into the space previously occupied by the central core section; and

Fig. 8 is a -sectional detail taken substantially on the line 8-8 of Fig, 7.

In the description of the invention like parts have been indicated by the same reference numerals in the several ngures. The apparatus comprises a supporting structure including uprights I which may rest on a suitable foundation 2 and are preferably formed of iron or steel. A table or bed 3, which may be an iron or steel casting, is mounted in a generally horizontal position on the upper ends of the uprights I.

Slidably supported on ways 4 of the table or bed 3 are mold sections 5 and 6 which are movable toward and away from one another and have their meeting faces suitably formed or recessed as shown at I2 to define the exterior of the piston or other article to be cast, indicated at A, and also suitable passages for introducing molten metal into the casting cavity. For example, a centrally disposed vertical passage II may be provided which forms sprue 1 on the piston A when the molten metal freezes in the mold.

Levers 8 pivoted at 9 to the bed 3 are connected by adjustable linkages I8 to the mold sections 5 and 6 so that the latter can be moved toward and away from one another and positioned on the ways 4 in definite relation with respect to one another and the sectional core to be later described.

Core pins I5 are slidably mounted in the mold sections 5 and 6 and have tapered ends I6 which project into the casting cavity when the mold is assembled in pouring position to form aligned apertures I1 in the piston A. These passages are later machined to receive a connecting rod pin. The pins I5 have heads I8 which limit the movement of the pins into the casting cavity and each of the pins is formed with rack teeth I9 engaged by the toothed end of a vertically disposed rod 20 rotatably mounted in the corresponding mold section. Handles 2I secured on the upper-ends The central section 21 of the core is mounted on a support 32 secured on the upper end of an actuating or power driven rod 33. This rod has a piston 34 (Fig. 1) secured on its lower end and reciprocable in a cylinder 35 secured by an upper end member 36 in an opening 31 formed in a cross member 38 supported by the uprights I. The foundation 2 for the apparatus may be formed with a pit 39 to receive the lower end of the cylinder 35. The top end member 36 and a. bottom end member 40 on the cylinder 35 are connected by conduits 4I and 42, respectively, through control valves (not shown) to a suitable source of fluid or air under pressure. Thus, air or fluid under pressure can be introduced into the cylinder 35 either above or below the piston 34 to force the same up or down as desired to either raise or lower the rod 33 and the central core section 21.

Supported on the cross member 38 is a bracket which has a vertically disposed guide portion 46 engageable with one side of the support 32 which slides therealong. Preferably, a vertically extending key 41 is secured in the guide portion 46 along the face thereof and is slidingly received within a recess 48 in the support 32.

The mechanism for supporting and actuating the outer core sections 28 and 29 includes members 49 and 50 formed with T-slots 5I, into which correspondingly shaped portions 52 of the base of the core sections 28 and 29 are intertted. The lower ends of the core base portions 52 are received behind lips 53 of the supports 49 and 50 and bolts 54 which extend through the supports 49 and 50 are threaded into the bottoms of the core pieces to secure the latter in the T-slots 5I of the supports,

The support for the core section 29 is tiltably carried by a pivot pin 51 and is disposed between the ends of pivoted members or arms 58, which are also received on the pivot pin 51 to support the same. The arms 58 are plvotally supported on a pin 59 carried by a bracket 68 secured to the underside of the table or bed 3 at a point remote from the opening 26 in the mold base. Thus, the mold section 29 may be raised or lowered through the cylindrical opening 2 6, the arms 58 describing an arcuate path and the of the rods 20 enable the latter to be rotated for movement of the pins I5 into and out of the casting cavity.

A ring-like base member 22 is formed with a circumferentially extending radial flange 23 which seats on a depressed shoulder 24 of the table 3. The base 22 extends downwardly through an opening 25 in the table and a cylindrical passage or opening 26 is formed in they base member to receive the multi-part core,

The core comprises a central section 21 and outer sections 28 and 29, the latter being disposed on opposite sides of the center section and having recesses 30 which form inwardly directed or laterally extending bosses 3I on the inside of the,

skirt of the piston A. These bosses have therein the openings I1 dened by the tapered ends I6 of the core pins I5.

core support 50 pivoting on the pin 51. Desirably, a separator 6I is recived on the pivot pin'59 between the arm members 58 and is secured to the latter by means of a bolt 62, so that the separator rotates with the arms. A counterweight 63 is mounted on the end of an arm 64 threaded into the separator 6I and balances the weight of the core section 29 and the mechanism for supporting the latter, so that the core is normally held thereby in its uppermost position and the raising and lowering of the core section is facilitated.

A depending extension 65 of the core support 50 has secured in its lower end or foot a transverse guide pin 66 which extends into a slot 61 formed in a cam member 68 secured to the crossl member 38. 'I'he foot of the extension'65 has a toe portion 69 which is directed toward the path of the support 32 for the central core section. The support 32 has a knob-like portion 1li-which bears against one side 1I of the extension 65 as the central core section 21 is lowered by the downward movement of the piston 34. As the central core section approaches its lower limit of Imovement, the knob 10 of the support 32 bears against the curved toe portion 69 of the extension 65 on the support 58 and forces the toe to path.

the right, as viewed in Fig. 5. movement y tilts the support I) and the mold section 29 in a counter-clockwise direction on the pivot 51, as shown in Fig. 5, thus freeing the core section 29 kfrom one of the wrist pin bosses 3| of the piston A, and moving the core section into the space vacated by the lowered 'central core section 21 The upper end of the cam slot 61 has a hori-l zontal portion 14 which receives the cam` pin 66 when the core sections are in assembled position (Fig. 1). Accordingly, while the central core section 21 is being withdrawn from a casting by ends of the pin 81 beyond the sides of the extension portion 85 of the core support are struts or arms'89 which extend upwardly in an oblique direction and across the path of the pivot pin 51 which carries the support for the core section 29. The upper ends of the strut arms 89 are formed with seats 90- engageable with the ends of the pivot pin 51 as the latter is lowered by the interconnection of the parts with the piston 34. Weights 9| mounted on the ends of levers 92 secured to the arms 89 adjacent the pivot 81 normally hold-L the arms 89 against pins 93 carried by the extension portion 85 of the support 49. By this arrangement the arms 89 are remechanism for` the core section 29 is tilted as shown in Fig. 5, the cam pin 66 is in line with the -downwardly extending portion of the cam groove 61 which controls the movement of the core section 29 cooperatively with the support members-or arms 58 and restricts the downward movement of the core section to a predetermined The extension 65 of the support 50 is centrally slotted or cut away, as indicated at 15, and re-l ceives a hook member or arm 16 which is mounted on a pivot pin 11 extending through the upper end of the cutaway portion of the extension and secured in the sides of the extension. The member 16 hangs downwardly in the slot or groove 15 and lower end or hook vportion'18 thereof is disposed slightly below the toe 69 and in the path of the knob-like portion 10 on th. support 32. A weight 19 mounted on the end of an arm 80 tained in correct position for engagement of the pivot pin 51 in the seats 90 upon lowering of the outer core section 29. After the pin 51 has engaged the arms 89, the latter are thereby forced downwardly and to the left, which causes a shifting of the pin 81 in the slot 88 from the right to the left, so that the support member 49 and the outer `core section 28 are tilted in a clockwise direction to substantially the position illustrated in Fig. '7. In this position the core piec'e 28 has been freed from the casting so that it clears the lateral or inwardly extending wrist pin boss 3| threaded into the upper portion of the member 16 holds the latteiI against the knob 10 on the support '32 during the lowering of the latter, so that when the support and outer core section 29 are tilted by the interengagement of the 'toe 69 and knob 18, the hook 18 is retained in the path of the knob to be engaged by the latter, as shown in Fig. 5. Since the hook 18 is below the end of the toe 69, the knob 1U does not engage the hook until after the guide pin 66 has been shifted into alignment with the downwardly extending portion of the cam slot 61. As` the central core support 32 is drawn downwardly from the position shown in Fig. 5, the tilted core section 29 is lowered simultaneously therewith by the interengagement of the hook 18 with the knob 10. During this .'movement the outer core section 29 is guided over apredeterminedv path by the cam slot 61 in cooperation with the pivoted arms 58. Thus, objectionable contact between the core section and the lateral or inwardly extending projections on the skirt of the fresh casting is avoided.

The support 49 for the outer core section 28 is pivotally mounted on a pin 83 carried by a bracket 84 secured to the under side of the table or bed 3 adjacent the cylindrical opening 26 in and is positioned in the space previously vacated by the central core section 21 and the other outer core section 29. The seats `9|) on the upper ends of the arms 89 are so formed as to provide intertting engagement between the parts, which prevents endwise movement of the arms 89 relative to the pins.

' In operating a mold of the character described,

the molten metal is poured into the casting cavity of the assembled mold shown in Fig. 1, the cavity being formed above the base 22 by the mold sections 5 and 6 around the core sections 21, 28, and 29. After solidic'ation of the metal the pins l5 are retracted by rotating the handles 2|, and the mold sections 5 and 6 are removed from the casting in `the usual manner to the position shown in Fig. 4. The operator then introduces fluid orfair under pressure into the upper end of the cylinder 35 to force the piston 34 downwardly. In this manner the support 32 carrying the central' core section 21 yis lowered. After the central core section has been withdrawn from 'the casting, the pressure. of the knob 10 against ing central core section. The connection between the supports for the central and outer mold sections thus includes a lost motion arrangement which' permits the center core section to be withdrawn from the casting before any movement 'of the outer core'section occurs. As lateral pressure is exerted against the extension 65 of the outer core support by the knob 10, the support 32 bears laterally against the guide portion 4S of the bracket 45, thus preventing lateral displacement of the central core or the actuating rod 33 therefor,A and holding the central core section 21 to a straight line movement. After the initial lost motion travel of the support 32 and the tilting of the core section 29 to the position illustrated in Fig. 5, the hook 18 engages the knob 10 so as to be drawn downwardly by the continued movement of the support 32. In this manner the core section 29 is withdrawn from the casting A through the space previously occupied by the 4central core section 21, the pin 66 being guided in the cam slot 61 to hold the core section 29 and the support 50 therefor to a predetermined path of movement. After a second period of lost motion during which the outer core section 29 is withdrawn from the casting and the central core section 21 is further withdrawn, the pin 51 is engaged in the seats 90 of the arms 89, as indicated by the broken lines of Fig. 7, forcing the latter to the left to the position shown by the full lines of Fig. '1. In this manner the outer core section 28 is tilted to the position illustrated in Fig. '7, so that it clears the lateral extensions on the inside of the casting, permitting the latter to be removed by the operator.

To reassemble the core for the next casting operation the operator introduces air or uid under pressure into the lower end of the cylinder 35, thereby forcing the piston and rod 33 upwardly. The knob or hook engaging member 10, moving upwardly, permits the support 50 to be raised by the weight 63 to elevate the outer core section 29 to its correct position with respect to the mold base 22. As the arms 89 are released by the pin 51, the weights 9| tilt or return the arms against the pin's 93 and also tilt the support 49 on the pivot pin 83 so as to move the outer core section 29 substantially to its correct position with respect to the mold base 22. The upward movement of the core section 29 is guided by the movable or pivoted members 58 and the pin 56 in the cam slot 61. A shoulder 94 on the outer core section 29 engages the bottom of the mold base 22 to position the same and to limit the upward movement of the core section. Preferably, the central core section 21 is of tapered form so that it bears progressively against the sides of the outer core sections 28 and 29 to support the latter in correct relationwith respect`to one another,

i and to move the same to their correct positions with respect to the mold base. As shown in Eig. 3, sides 95 of the central core section 21 maybe `dished or hollowed so that each of the outer core sections may have interfitting relation with the central core section, thereby maintaining Ya proper relation .of the parts when the mold core is assembled. At the upper limit of movement -of the central core section 21, the top of the support 32 engages the bottoms of the outer core sections 28 and 29.

. The present invention provides a generally improved multi-part core for casting cup shaped articles such as pistons and the like in permanent molds. The apparatus includes novel mechanism for automatically tilting several core sections in succession into the central region of the cast tended period' of trainingor instruction. Furthermore, the apparatus can be quickly and economically operated,` thereby lowering the cost of production of the articles being cast, whileincreasing the number of articles that can be made in a given period of time. y

The principles of the present invention may be utilized in various ways, numerous modifications and alterations being contemplated,y substitution of parts and changes in. construction being resorted to as desired, it being understood that the embodiment shown in the drawings and described above is given merely for purposes of explanation and illustration without intending to limit the scope ofthe claims to the specific details disclosed.

What I claim is:

1. A piston mold comprising a supporting structure, mold sections recessed to denne a casting cavity, a core having central and outer sections, means having connection with the central section and operative to withdraw the same from a casting, a member mounted on the structure and guided thereby for movement over a predetermined path, said member having pivotal connection with-the outer sections, and mechanism secured to the outer section and adapted to Amake connection with said means during the withdrawal of the central section to be shifted by the operation of the withdrawing means to tilt the outer section on the pivot and then withdraw the outer section while the latter is guided by said member.

2. A piston mold comprising a supporting structure, a core having sections one of which is shaped to form a lateral extension inside a piston, means pivotally mounting said shaped section on the structure, mechanism for supporting another section and guiding the same as it is withdrawn from a casting, and a member pivoted on the mounting means and engageable with the supporting means to be actuated by the latter to rotate the shaped section on the pivot of the mounting and free said shaped section from the lateral extension. l

3. A piston mold permanent core comprising a pair of outer sections each formed to-shapea lateral projection on the inside of a casting, a central section and means actuable to withdraw the same from the linterior of a casting, first mechanism making connection with said means after withdrawal of the vcentral section,-to be actuated thereby and having connection with one of the outer sections to shift the same to clear the lateral projection formed thereby and to then withdraw such section through the space cleared by the withdrawal of the central section, and second mechanism actuated by said means after said shift to move therother outer section into said space. L

4. A mold comprising a supporting structure, mold sections mounted on the structure and formed to provide a casting cavity, a pair of spaced core sections disposed in the cavity and mounted on separated pivots carried by the structure, one of the pivots being movable and the other being iixed, a central core section disposed between the spaced core sections, means movable for withdrawing the central 'core section, and means disposed in the path of said withdrawing means to be actuated by the movement thereof, said last named means having connection with the movable pivot to shift the latter and thereby withdraw one of the first mentioned core sections from the cavity.

5. A piston mold core comprising a central section, a pair of outer sections,` means supporting the central section and actuable to withdraw the same from a piston casting, and mechanism having connection with the supporting means and actuable thereby to tilt one of the outer sections into the space formerly occupied by the central section and withdraw the same from the casting and to then tilt the other outer section into said space.

6. A piston mold comprising a core having an outer section formed to shape a lateral extension inside the piston, a section adjoining the outer section, mechanism connected to the adjoining section to withdraw the same from a piston casting. and co-acting members linterconnecting the sections and operative to shift the outer section into the space previously occupied by the adjoining section by the movement of the adjoining section.

'1. A core for a permanent piston mold comprising a number of sections including an outer section formed to shape a lateral extension inside the piston and a central section disposed to normally support the outer section, means for supporting the central section and operative to withdraw the same from a piston casting, mechanism including a pivot for supporting the outer section and having connection with the support means to first tilt the outer section on said pivot into the space formerly occupiedby the central section and, upon continued withdrawal move-` ment of the central section, to then withdraw the outer section synchronously with said withdrawal movement of the central section. 8.'A core for a permanent piston mold comprising a pair oi outer sections formed to shape lateral extensions on the inside ofthe piston casting, a central section normally disposed between-the outer sections, means for supporting the central section and for withdrawing the same from between the outer sections, and mechanism for supporting the outer sections and including pivots, said `mechanism being adapted to make connection with the support means after predetermined withdrawal movement of the central section to be actuated thereby to tilt one of the outer sections into the space formerly occupied V and having 'pivotal connection therewith, .a

pivotable member' for supporting the other outer section, means connecting the movable member with the supporting means to be moved assign-1.

. 12.- A piston mold core comprising withdrawlable sections. means for supporting and actuating one of the sections to withdraw the same from a casting, means pivotally mounting another of the sections, and said supporting and mounting means having co-acting elements which bear against one another and progressively tilt said other section on the pivot mounting during withdrawal of saidv one section, /nd a hook disposed to connect said sections after a predetermined withdrawal movement of said one section for withdrawal thereby of saidv other section.

13. A piston mold core comprising separable sections each having means for supporting the same and for withdrawing the supported section from a casting, one support including a pivot,

- and said pivot support and another section supby the central section and withdraw such outer thereby Eafter a predetermined withdrawal of the central member, and means connecting the pivotable member with the supportingmeans to be pivoted thereby after a predetermined withdrawal of the central member.

10. A piston mold core comprising withdrawable sections, means for supporting and actuating one of the 'sections to withdraw thesame from a casting, a hook carried by another of the sections, and means urging the hook against said actuating means to engage the same for withdrawal of vsaid other section by the movement of the actuating means. v

11. Alpiston mold core comprising withdrawable sections, means'for supporting and actuating one ofthe sections to withdraw thesame vfrom a casting, means pivotally mounting another of the sections', and said supporting and mounting means having co-acting elements which bear against one another and'progressively tilt said other section on the pivot mounting during withdrawal of said one section.

port having co-acting members including a cam for progressively tilting said pivot support means duriing the withdrawal of said other section suppor 14. A mold for making cup shaped articles comprising a supporting structure, a core having sections one of which is shaped toA form lateral extensions inside the articles, means mounting the shaped' section for pivotal movement on the structure, mechanism for supportingv another section and guiding the same as it is withdrawn from an article, and means on the mounting means and having connection with the supporting mechanism to be actuated by the latter during withdrawal of said other .section to rotate the shaped section on the. pivotal mounting and thereby free the shaped section from the lateral projections.

15. A mold for making cup shaped articles comprising a supporting structure, a core 'having sections shaped to form lateral extensions inside4 the articles, means mounting one of the sections for pivotal movement on the structure, mechanism for pivotally supporting another section and guiding the same as it is withdrawn from an article, means for actuating thelmechanism to rst rotate said other section to free the same from one of the lateral extensions and to then withdraw the same while guided by the mechanism, and means on the mounting means and having connection with thesupporting mechanism to be actuated by the latter during withdrawal of said other section to rotate said one section on the pivotal mounting and thereby free said one section from one of the lateral projections.

16. A mold for making cup `shaped articles comprising a supporting structure, a core having a pair of outer sections and a central section therebetween, means for supporting the central section and actuable to withdraw the same from between the outer sections, means mounting one of the outer sections for pivotal movement on the structure and adapted to guide such section as it is withdrawn from an article, and means connecting the mounting means to the supporting means for actuation thereby during withd rawal of lthe'central section to rotate said one 'sectioni into the space `provided by the withdrawaly of the central section and then withdraw said one section through such space.

17. A mold for makingl cup shaped articles comprising a supporting structure, a core having a pair of outer sections and la central sectiontherebetween, means for supporting the central section and actuable to withdraw the same from between the outer sections, means mounting one of the outer sections for pivotal movement on the structure and adapted to guide such section as it is withdrawn from an article, means connecting the mounting means to the supporting means for actuation thereby during withdrawal of the central section to rotate said one section into the space vprovided by the withdrawal of the central section and then withdraw said one section through such space, and a tiltable mem-

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