US1420903A

US1420903A - Metal mold

Info

Publication number: US1420903A
Application number: US425788A
Authority: US
Inventors: Clair J Amick
Original assignee: ALUMINUM MANUFACTURES Inc
Current assignee: ALUMINUM MANUFACTURES Inc
Priority date: 1920-11-22
Filing date: 1920-11-22
Publication date: 1922-06-27
Anticipated expiration: 1939-06-27

Description

C. J. A`VHCK.

METAL MOLD.

APPLICATION FILED Nov. 22. 1920.

Patented J une 27, 11922.

2 SHEETS-SHEET' I.

fa 3j Patented .I une 27 2 SHEETS-SHEET 2.

C- I. AIVIICK.

METAL MOLD.

APPLICATION FILED NOV. 22, 1920.

III

II III II naar@ CLAIR J'. AMICK, 0F CLEVELAND, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS, T0

ALUMINUM MANUFACTURES, INCORPORATED, 0F CLEVELAND, OHIO, A. COR- PORATION 0F DELAWARE.

METAL MOLD.

needs.

Specication of Letters Patent. Patented June 2'?, 1922.

Application filed November 22, 1920. Serial No. 425,788.

T o all whom. t may Concern.'

Be it known that I, CLAIR J. AMICK, a citlzen of the United States, residin at Cleveland, in the county of Cuyahoga, tate of Chio, have invented certain new and. usevful Improvements in Metal Molds, of which extending projections, especially pistons for internal combustion engines. lt relates in particular to multiple part cores of the general type disclosed in the patent to F. A.

Parkhurst, No. 1,296,596.

One object of the invention is to provide a core for cast-ing internal combustion'en'- gine pistons havingl a relatively small clear-L ance between the inner ends of the wrist pin bosses.

` Another object is to provide a core for casting 'internal combustion engine pistons having relatively long wrist pin bosses. Another object is to provide a multiple part core, .the various parts of which have hcontacting faces so formed as to prevent movement of the assembled each other.

Another object is to provide a multiple part core for casting pistons for internal parts relative tol -combustion engines which will withstand ordinary usage and the action of high temperatures and which may be cheaply maintained in mechanically satisfactory condition.

Other objects will be pointed out in the appended specification.n

. In the accompanying drawings forming a part of this specification:

Figf 1 is a top plan view of a mold for making pistons, assembled with a core con-- structed in accordance with my invention.

Fig. 2 is an end elevation of the mold shown in Fig. 1.

Fig. 3 is a vertical section taken on line 3 3, Fig. -1 showing the core in section and the gate and mold cavities filled with metal.

Fig. 4C is a fragmentary cross section taken o on line 1 -4, Fig. 3. l

Fig. 5 is a plan view in section taken on line l5--5, Fig. 3, nearthe top of the core.

and from each other. tions of the mold body are preferably made Fig. 6 is asimilar view taken on line 6-6, Fig. 3, through the bosses of the casting.

Fig. 7 shows the order of removal of core parts from the casting, the center section having been removed and the two' side sections moved inward to clear the circumerentially inwardly lextending projection at the open end of the casting.

Fig. 8 is a similar view showing the manner of removing the quarter sections of the core from beneath the bosses of the casting. Fig. 9 is a view similar to Fig. 5 of a modified form of core.

In the interest of brevity and because my invention constitutes an improvement in permanent mold cores of the general classI disclosed in Patent No. 1,296,596 reference is made to that patent for a detailed descrip# tion of the yconstruction and operation of the mold, the pouring gate and the means of 'venting the mold. These parts will be described only in sufficient detail to make clear the operation and useof the core which is the subject of my invention. It will, however, be understood that while my improved form of core is capable of use with molds of the type disclosed in the above mentioned patent, it is not limited thereto since various other types of molds could be employed.

Referring to the construction shown in the drawings, the body of the mold is shown as comprising a base 1 and

complementary members

2 and 3 movable on the base toward These three main secof `cast iron.

Each of the `

complementary members

2 and 3 comprises an inner side wall 4f, end' to the

end walls

5, 6. The outer side of each of the complementary members is formed together, as shown in Fig. 1. Each wall 4 is formed between its ends withl a semi cylindrical portion 4`a and the lower parts of these semi cylindrical walls 4a form the outer side wall of the mold cavity, the bottom of said cavity being formed by the upper face of the base 1. -The upper face of the base 1 is formed with a central depression 1b which provides for a work spot on the head of the piston casting.

At la the base 1 is provided with a circular shoulder and the

bottom walls

8, 8 of the

side members

2 and 3 are recessed at 8a to receive the shoulder 1a whereby ,the

mold members

2, 3 are properly alined relatively to each other and also centered on the base plate. Supplemental means for alining the side members of the mold may be employed if desired, such for example, as pins 13 which extend upward from the base 1 to be engaged by recesses 4'b formed in the walls 4 of the sideV members of the mold.

Above the mold cavity proper semi-circularwalls 4a are recessed to receive inserts 14, 14 -which are rigidly secured to the

mold members

2, 3 by screws 15 as indicated in Fig. 5. These inserts, which are provided with surface grooves 14a, 14h, 14c and 14d for the purpose of venting the mold cavity are preferably arranged to form the top wall of said cavity as indicated in Fig. 3.

At v16 are devices for locking the

mold members

2 and 3 together in operative position on the base.

The main core of the mold which is designated as an entirety by the numeral 17, is preferably made of steel and comprises in the preferred construction shown, three middle sections, 17a, 17h, and 17'e which are arranged in a row extending, in the upper part of the core, from one side to the other of the cylindrical space between the` upper parts of the walls 4, i. e. the parts occupied by the inserts 14, (Fig. 5). The spaces at the two sides of the

middle sections

17a, 17", 17c are occupied by two pairs of sections, 17d, 17d, which for convenience, 1 will call quarter sections.

'In present practice with the cores of this type as shown by the above mentioned patent, the interior section is substantially rectangular in horizontal cross section, having four plane faces. The interior section of my improved core which, in outline, has a substantially rectangular, horizontal cross section, is however provided with a longitudinal depression in each face. The faces of the opposite narrow sides or edges of the section 17b have substantially V shaped depressions formed therein. Each depression provides two laterally inclined inwardly eX- tending surfaces 18El and 18b uniting to form one wide Vshaped surface.. Two exterior sections each having their vinner surfaces 19 and 19b shaped to conform to these V shaped surfaces, closely engage with the interior section throughout the lengths of their adjacent faces.

The two remaining faces of the interior section namely the wide side faces also have depressions formed therein which provide` two outer surfaces 20, two laterally and inwardly inclined surfaces 20"J and an inner surface 20c, the surfaces 20h being interposed between and joining surfaces 20a and 20C. A pair of quarter sections 17dl are suitably formed and adapted to engage with each of the side faces of the interior section so that the sections will lie in close fitting engagement therewith when assembled. lBy reason of the V shaped contact between the two exterior sections and the interior section of the middle row of sections, lateral movement of these sections relative to one another is prevented when the core is assembled in themold. Movement of the interior section relative tothe pairs of quarter sections is similarly prevented by thel substantially beveled, surface contact between the sections. Any tendency of the middle row of sections to tilt from a vertical position in the mold due to a wearing away of the inserts is thus effectively resisted by the laterally inclined surfaces 20c which engage the quarter sections, even though the insert has worn considerably. By reason of the shape and arrangement of thecontacting surfaces betweenthe sections of the core, the sections are easily held in assembled relation and are preventedfrom movement relative to each other with the result that the core becomes practically a unitary structure.

The core surfaces which are located be low the inserts 14 and which form the inner side and 4bottom walls of the mold cavity proper are provided with various depressions to give the desired contour to the interior of the piston casting. As indicated in Figs. 6 and 7 the quarter sections of each pair are shaped with the recessmr, to form the wrist pin bosses of the piston casting, one-half of the recess being formed in each quarter section of the core. It will benoted that the boss recesses, a, in each pair of'sections eX- tend so deeply into the sections that the inner end walls, a', lie within the cross sectional outline of the interior section. That is, a plane joining the two surfaces 2()a on one side of the interior section would cut across recess, a, the end wall, (1.', falling within the interior sections as thus outlined. In other words the boss recesses, al, extend into the depressions in the interior section and the bosses formed in the recesses are thus relatively very long as compared with those formedV in recesses' which extend only to the surface of the interior section as has been the practice heretofore. Furthermore it will be noted that relavinsonne tively small space is providedibetween the inner end of the boss recesses due to the present formation of the core sections, as compared with present practice, the result being that pistons may be cast with a smaller clearance between the inner ends of the wrist pin bosses than at present. f

The construction of the sections 17d permits these sections to be moved laterally apart and disengaged from the :bosses of the casting. I y

In the construction shown the adjacent faces of the core sections 17d are recessed at b, c to form strengthening ribs between the pin bossesand the side walls of the piston, and at their lower-ends each pairof quarter sections is recessed at d and the interior middle section 17d is recessed at e, said recesses al, e providing for a strengthening and heat dissipating rib on the inner side ofthe piston head in a plane parallel to the axis of the pin bosses and in line with the ribs formed by the'recesses b, c.

At its lower ends the core is of reduced diameter at 17 to make the side wall of the piston casting adjacent the head of ample thickness to accommodate packing rings. And between the recesses, a, for the piston pin bosses and the`upper lend of theA mold cavity, the core is formed withl a circumferential depression, f, to provide an internal flange on the skirted piston near the open end thereof for the double purpose of strengthening and stifening the lower end of the piston and providing space for a wiping rlng.

It is exceedingly important that the core sections be rigidly and accurately supported in relation to each other and in relation to the body of the mold and I have made provision to this end. The dimensions of the cross sections are such that when assembled the core snugl lits the cylindrical wall formed by the inserts 14 of the mold body. In addition the

core sections

17a, 17 are formed with outwardly turned flanges 18 which rest upon the top walls 7 of the mold body to limit the downward movement of said core sections, and the sections 17d are To insure the accurate positioningof the` core circumferentially a key 22 is suitably secured as `by screws 23 to an insert 14 and located so that it will engage each of a pair of quarter sections, the meeting faces of the quarter sections being cut away to form a key way 22a for engagement with key (Figs. 3, 4 and 5). No additional posi` tioning means is necessary since,.due to the cross sectional configuration of the core sections the sections are held in close assembled relation in the mold as noted above. rlhe middle Acore sections 17, 17c are tapered on' two sides toward their lower ends, the section 17b is similarly tapered on all four sides and the respective'sections arenicely fitted in their faces to each other and on their outer curvilinear faces to the mold walls 4a so that when the 'core is assembled in the mold body it is both accurately poin each of the

mold sections

2 and 3 so as'` to project into the pin boss cavity. A steel f wearin sleeve 32 is preferably provided for eac of thevpins, the :pin and the bore of the sleeve being correspondingly tapered to insure a snug it and the length of the pin being such that its inner end engagesl the metal of the quarter core sections as indicated in Figs. 4, 6, and 7.

The body of the mold may be formed or provided with any suitable form of gate for the introduction ofthe molten metal into the mold cavity.,

To facilitate the escape of air and gases from the mold, special venting means may be and preferably are-provided. 1n the construction .shown the inserts 14 are formed.

with grooves 14a on their inner faces, with grooves 14b on their outer faces and with grooves 14, and 14d on their top and bottomv faces, respectively. These rooves insure the escape of. air or gases w ich find their4 way to the top of said mold cavity. Also the base 1 may be bored out central y to receive a plug 34 which is providedwith ats or grooves on its outer surfaces which constitute passages for the escape of air or gases downward through the base. v

I Ah ave also formed grooves 35, and 36 in one or both .of the adjacentjfaces of each pair of quarter sections, as shown in Fig. 4. Air or gases rising in the rib recesses, e, escape upward through the ooves 35 into the boss recesses-y a, and t ence through y grooves 36 into grooves 14?, 14b and 14".

In the interest of clearance the size of. i

the venting grooves or passages is exaggerated as shown in the drawings, as will read-V ily be understood by those skilled in the ,permanent mold art.' ,e

In. assemblingv thecore and m'old herein described the

side members

2 and 3 are moved together into operative position on the base -1. Next the quarter sections 17d are lowered into approximately the'positions they should occupy, the pair of sections having key way 22a engaging with key 22; then sections 17 a and 17c are insertedbetween j the 'pairs of quarter sections and finally -rately position all of the sections.

interior section 17 b is inserted so as to accu- When the

side members

2 and 3 are clamped together by locking means 16, the core sections are held in close contact with one another and constitute practically a rigid unitary structure. @The core pins are next inserted and the molten metal poured into the mold' cavity. After the casting has solidified sufficiently the core pins are first removed7 then theinterior section 17b of thev main core is removed by withdrawing it axially or longitudinally upward. Then the inside metal core sections 17a and 17e are moved laterally inward, fthe necessary clearance .being afforded by the upward movement,

and' preferably entire removal of the section l17", and when they have cleared-the internal flange D of the casting, as shown in Fig. 7; they are drawn lon itudinally upward and out of the mold. ext, by grasping the handles of one pair of the quarter sec- 47 are also provided with substantially convex surfaces 5l for engagement with surtions, said sections are swung laterally into the positiony indicated for one of said sections in.v Fig. 8. In this view the quarter section is clear ofl the pin boss but not of 'circumferential flange D of the casting, However, by tipping the upper end of the Vsection radially inward it is made to clear the fiange D, whereupon it "can be withdrawn longitudinally from the mold. The

first pair of quarter sections are thus with'- l drawn simultaneously, or nearly so, and

thereupon the secondjpair can be freely swung laterally clear of the adjacent boss A of the casting and then withdrawn longitudinallyfrom the mold.

After theY removal of the core 17 the mold members 2and 3 are unlocked and drawn apart far'enough to permit the casting to be Withdrawn, whereupon they are again moved into engagement with each other, locked and the operation repeated.

In Fig. 9, a modified form of core is shown. It resembles the preferred 'formof core in all respects except in the configuration of the` contacting surfaces, lof the interior and exterior sections. and 49 of the interior section 47h are substantially concave. The 4pairs lof `quarter sections-.47d are shaped with i substantially 'convex surfaces' 50 for engagement with the corresponding surfaces 48 of' the interior section 47". The exterior sectionsf(a and faces 49 of the interior section. Due to .the

- nature and shape of the contacting surfaces The surfaces 48- of the vcore sections, the assembled core parts may be easily held in assembled relation in the mold and `movement relative to one another prevented as described above in conf` nection with the preferred form of construction.

The assembled core is positioned in the mold by a key 53 secured to the adjacent insert and a keyway 53a formed in the meeting faces of a pair of quarter sections 47d in a manner similar to that described which have interlocking engagement withA the mold body act to position the assembled core accurately in the mold. The several parts of the middle row of sections are prevented from lateral movement relative to each other by the nature of the contacting faces while the middle rowy of sections is prevented fromlateral movement relative' to the pairs of quarter sections by reason of the shape of the contacting faces. The various sections, therefore, comprise a structure which is capable of being easily held in assembled relation as a practically unitary structure.

Furthermore, by reason of the relatively thin interior sectlon, correspondingly deep boss recesses in the quarter sections make possible inwardly extending projections on the castings which are longer in relation to the diameter of the casting than have been made heretofore in permanent molds and which also have a smaller clearance between the -innel ends thereof than heretofore.

In castinghigh melting point metals, such as aluminum alloys, edges and corners of core sections when exposed to the action of the molten metal have a tendency to wear away quickly. My improved form of core eliminates much of the trouble arising from this cause. In multiple part cores of this general type in which any section or sections for instance the middle rowof sections, may move or tilt relativel to the remaining sections, corners and 'edges at the end of the sections will'be directly exposed to contact with the molten metal. Such contact results in a short life of the. core and in necessarily high maintenance costs. Y

In my core, however, no movement of the various parts is possible and it therefore is ynbt subject to such excessive wear and the high maintenance costs incident thereto.

It is to be understood that the construction of my improved core-can be varied widely without departing from my invention, and that the yspecific form of construction dis'- closed has been shown simply for` the pur- .i

Laaoeoe pose of explanation and illustration, the scope` of the invention being defined by what is claimed.

IWhat is claimed:

.1. In a permanent mold for casting pistons the combination with a permanent mold body having a cavity open at one end and adapted to form the outer head and side walls of a piston casting and having a gate through which molten metal can be introduced into the cavity, of a permanent core supported on the mold body within a surrounding wall thereof and extending `into the cavity of tle mold to form the inner head and side walls of the piston casting, said core comprising an interior section having wide edge portions and a relatively thin central portion formed by longitudinal-ly extending depressions in opposite sides of the said section, and a plurality of exterior sections surrounding Athe said interior section, pairs of the exterior sections having longitudinally extending enlarged portions adapted to seat in the said depressions in the interior sections, each pair of exterior sections having a wrist pin boss recess extending inwardly into said enlarged portions thereof whereby a piston having relatively small clearance between the inner ends of the wrist pin bosses may be cast, another pair of the said exterior sections disposed at the end sides ofthe said interior-section being inwardly shiftable upon removal of the said interior section.

2. In a permanent mold for casting pistons the combination with a permanent mold body having a cavity open at one end and adapted to form the outer headand side walls, of a piston casting and having a gate through which molten metal can be introduced into the cavityfof a permanent core supported on the mold body within a surrounding wall thereof and extending into the cavity of the mold to form the inner head and 1side walls ofpthe piston casting, said core comprising an interior section having a plurality of side surfaces each formed with a longitudinally extending depression, and a plurality of exterior sections surrounding the interior section, each exterior section having a surface conformable to and adapted to engage with an adjacent surface of the said interior section whereby the said s'ections are prevented' from movement relative to each other when in assembled position.

3. In a permanent mold for'casting pistons the combination with a permanent mold body having. a cavity open at'one end and adapted to form the outer head and side walls of a piston-casting andhaving a gate through which molten metal can .be 4introduced into the cavity, of a permanent core supported on the mold body within a surrounding wall thereof and extending into the wcavity of the mold to form theinner head and tons the combination with a permanent mold l body having a cavity open at one end and adapted to form the outer head and side Walls of a piston casting and having a gate through which moltenl metal can be introduced into the cavity, of a permanent core supported on the mold Ebody `within a surrounding wall thereof and extending into the cavity of the mold to form the inner head and side walls of the piston casting, said core comprising an interior section .having edge surfaces and side surfaces, the said side surfaces consisting of a plurality of laterally inclined surfaces formed by longitudinally extending depressions section, each exterior section having laterally inclined surfaces conformable to and adapted to engage with the surfaces of the interior4 section whereby movement of the sections and a plurality of exterior sections surrounding the interior Y relative to each other is prevented when the Y sections are in assembled position.

5. In a permanent mold for'casting pistons the combination with a permanent mold body having a cavity open at one end and adapted to form the kouter head and' side walls, of a piston casting and having a gate through which molten metal can'be introduced into the cavity, of a permanent core supported on the mold body within a surroundin wall thereof and extending into the cavity of the mold to form the inner head and side walls of the piston casting, said core comprising an interior section having edge surfaces and side surfaces, each surface consisting of a plurality of laterally inclined surfaces formed b a longitudinally extending depression, an a plurality of exterior sections surrounding the interior section, each exterior section having laterally inclined surfaces conformable to and adapted to engage with the surfaces of the interior section whereby movement of the sections relative -to each other is prevented when the sections are in assembled position.V

6. In a permanent mold for skirted piston Y castings, theJ combination with a permanent mold body having a cavity open at one end and adapted to form the outer head and side walls of the piston casting and having a gate through which molten metal can be introduced into the cavity, of a permanent, sectional core supported on the mold body within a surrounding wall thereof and extending into the cavity of the mold to form the inner head and side walls of the piston casting, said core havin its outer surface formed with cavities to forma pair of pin bosses on the inner side walls of the piston casting and with a circumferential depression arranged to form an inwardly extending circumferential flange on theinner side walls of the piston casting, the said core also having a series of more than two sections arranged in a row across the mold cavity with two of them engaging the inner side wall of the casting and the said core supporting wall of the mold body at opposite points, and the'core having also sections arranged on opposite sides of said row of sections to engage the inner side wall ofthe casting, the sections at one side of thejsaid row of sectionshavin interlocking engagement with the mold ody, the several sections being formed and arranged so that the said interior section when moved endwise affords clearance to permit the outer sections of the core to be successively moved laterally out of engagement withthe pin bosses and the inwardly extending flange of the piston casting and then endwise out of the said casting.

In a permanent mold for casting pistons the combination with a permanent mold body having a cavity open at one end and adapted to form the outer heady and side walls of the piston casting and having a gate through which molten `metal can be introduced into the cavity, of a permanent core supported on the mold body within a surrounding wallthereof and extending into the cavity of the mold to form the inner head and side walls of the piston casting, said core comprising an interior section having wide edge portions and a relatively thin central portlon formed by longitudinally ex- .bosses may be cast. v

8. A collapsible core for a cup-shaped ar tending depressions in the opposite sides of the said section, and a plurality of exterior sections surrounding the said interior section, the sections on one side of the said lin-` teriorv section having interlocking engagement with the moldbody, and pairs of the exterior sections having longitudinally kextending enlarged portions adapted to seat in the said depressions in the interior section, each pair of exterior sections having wrist in boss recesses extending inwardl into t e said' enlarged portions thereo whereby a piston having an inwardly extending annular projection adjacent its open end and having a relatively small clearance between the inner `ends of the wrist pin ticle having inwardly extending projections -the inner ends of which are separatedby a relatively small space and also having an annular inwardly extending projection, comprisin an interior section substantially rectangu ar in cross section and provided with a longitudinally extending depression in each side face thereof, and a plurality of exterior sections surrounding the interior section each exterior section having longitudinally extending raised portions conformable to and adapted to seat in the said depreswardly extending projection between the said bosses and the open end of the said piston, said core comprising an interior section having four vertical side facestan opposite pair of said faces, adjacent the bosses,

being provided with a longitudinally extending depression, and a plurality of exterior sections surrounding the interior section, the exterior sections adjacent the bosses having longitudinally extending projections con-I formable to and adapted to seat in the said depressions of the interior section when the core sections are in assembled position, a pair of other exterior sections being positioned in contact with lthe other pair of interior corevertical faces, said last named pair of exterior sections being inwardly shiftable when said interior section is removed, to permit the sequential removal of said last named and the said irst named pair of exterior sections.

l0. A collapsiblejcore for an internal'coml bustion enginepiston having inwardly exilv tending wrist pin bosses, the inner ends'of which are separated by a relatively small space, and also having an'annular inwardly extending projection between the said bosses and the open end of the said article, coInprising an interior section substantially rectangular in cross section and provided with a longitudinally extending depression in the opposite side faces thereof adjacent the said bosses, and a plurality'of exterior sections 1 i 115 surrounding the interior section, the exterior sections adjacent the bosses having longi-y tudinally extending Iraised portions conformable to and adapted to seat in the said depressions of the interior section when the core sections are in assembled'position, an-

other pair of exterior sections adjacent the other side faces of the said interior section, being inwardly shlftablel upon removal of the said interiorsection.A

In testimony whereof, I hereunto aix myl signature.

i' CLAIR plJ. AMIGK.