US2233405A

US2233405A - Method of and apparatus for casting cylinder heads

Info

Publication number: US2233405A
Application number: US247872A
Authority: US
Inventors: Everett G Fahlman
Original assignee: Permold Co
Current assignee: Permold Co
Priority date: 1938-12-27
Filing date: 1938-12-27
Publication date: 1941-03-04
Anticipated expiration: 1958-03-04

Description

Mmh 4, 1941. E, G'. FAHMWMJ I2,233,405

METHOD OF AND APPARATUS FOR CASTING CYLINDER HEADS Filed Dec. 27, 1938 6 Sheets-Sheet 1 ATToRN BZW f5??? Mai'dl 4, 1941- E. G. FAHLM'AN 2,233,405

METHOD 0F AND `APPARATUS` FOR- CASTING CYLINDER HEADS Filed Dec. 27, lesa s sheefssheet 2 f INVENTOR EVERETT G. FAHLMAN ATTORNEYS March 4, 1941- E. G. FAHLMAN 2,233,405

A l METHOD of'Y AND APPARATUS FOR CASTING CYLINDER HEADS I Filled Dec. 2v, 1958 s sheets-sheet s Il, l Z4 X67 I /0 57 I .l I v 65 F gf 7 Z l INVENToR t ,4 EvERE'r'r G. FAHLMAM ATToRNgYs Ma-rch 4, 1941.

' METHOD or Arm APPARATUS Fon CASTING GYLINDER HEADS Filed-DBG. 27, 1958 -6 shams-Sheet 4 z5 5l y 22 '-10 84 7 Z0 E. G. FAHLMAN 2,233,405

EVERET'T G. FAHLMAN i March 4, 1941. I E, G, FAHLMAN 2,233,405

METHOD or :mn .APPARATUS FOR CASTING GYLINDER HEADS Filed uw. 27, 193e "s sheets-sheet s 12 Y I ATTORNEYS Mach 4 1941-'V y|-:. G. FAHLMAN A2,233,405

METHOD OP AND APPARATUSV FOR- CASTING CYLINDER HEADS.

Filed nec. 2v, 195e e sheets-sheets ,ATTORNEYS Patented Mar. 4, 1941 v 2,233,405 METHOD or AND APPARATUS Fon CASTING CYLINDER HEADS Everett G. Fahlman, Lakewood, Ohio, assignor to y, Cleveland, Ohio, a cor- The Permold Compan poration or Ohio Application December 27, 1938, Serial No. Y2i7,'87/?,

2c claims. (ci. zelsiii` This invention relates to permanent molds for casting aluminum alloys,-and a method of casting such alloys, and particularly to molds for and a method of casting aluminum he ternal combustion engines,

In the art of casting aluminum and its alloys it is an accepted fact that castings made in permanent molds are superior tothose made in sand. One of the advantages of permanent molds is that they allow closer tolerances inthe castings and increased strength is obtained becausel of the greater density produced by the chilling eiect of the metal of the permanent mold during the solldifying of the molten metal. f Aluminum and other light alloy cylinder` heads n have been used `on internal combustion engines for many years. i However, such cylinderheads have v'not met with complete commercialsuccess for various reasons such as their high cost. Such cylinder heads have been cast in permanent molds, but because ofy limitations in the permanent mold art inits present state of development, considerable scraploss usually resulted, giving rise to the 'relatively high jinanufacturingRoost'l mentioned.

ads for inby premature freezing of the casting metal. Castings of intricate design and'which have metal sections ofy different thickness tend to cause uneven heating of the various sections or parts of the mold, and this uneven heating of the mold sections aggravates the `rlimculty of properly introducing the metalinto the mold withoutmsruns and premature freezing. f Y

Another prolileizn`r to xbe `overcome `in the casting of intricate designs having portions of different thickness is the elimination of surfacefdepres- ,l sions and internal voids.l vThe high crystallization shrinkage of aluminumv and its. alloys results `in the drawing of molten metalby the relatively 7 thin, faster freezingy portions fffrom :heavier or l5 thicker sections of the casting; which;beeause of their higher heat content; freeze or'isolidify more slowly than` the thin sections.,y Accordingly, when the solidi'cation `of the thick or.. heavy section portions ofl the` casting takesplacepthereis in- 20 1, s uyflicient metal to completelydll i theI cavity and the deciencyfis made-up eitherhby surfacey depressions, `known :as sinksfsor internal voids. Where internal voids foccurrthe'fresulting casting Furthermore, n adapting conventional permanent moldingpracticeto the casting-of cylinderheads, the mold, designers have' resortedgtoinumerous ymo'diiications and alterations.- .f The ,castings pro- ,is unsound and of `decreasedstrength.y Further--` more, the. 'porosity of s the'casting lincreases/the possibility of y-uid leakage through the!r metal of 1 .the casting; a defect which :is quite. objectionable l duced have not exhibited the usual advantages of increased' strength; `smooth surface, and `freedom from porosity Icustomarilyfound in-permanent mold, castings as compared-with sand moldcast- One of ther prohlems intconnecti'on withrthe use1of permanent molds for aluminum alloy, castings of non-uniform cross +sectional-1orm or. of `imtricate design results Vfronfigtnlie `:tact that, due to the`rapidifreez1ng-, orlsolidiiication of` the;A molten metal inthemcle itis-aiment.. to, nowihemetsl intothemoldj cavityin such-manner that `defects in castings are notafrormd l'ffrea-scn of imperfect 111.11m cf the. moldfcnfacccuxitcf trapped-air or 'blocking of parts of; thel cavity ibygifreezlng metal. f 1 A. Primedimcultrfn ccnaecticnwith the use 0f "u permanent molds 4flo making ',aluininumgend Where heavy portions o1'` the' castings lare along ;l partingy lines of thei mol'df,A

1 the `casting cavity. f

in cylinderheads for internallcombustion engines.

x itfhas beenv common practice -i to `provide 1 riser f cavities 1 relatively f, large- -volume finf the', meeting -faces off athe mold sections adjacentthe heavy sectioned portions of c lsu-eh. risers 'are 'disposedA V35 that metal may be drawn into the casting- 'cavity ,f `from the :risers during vfreezing 'fof 'the met'al to v:Sl-ipplyfadjacentportions sof. thexcasting fwithv the 'gamount pf.: `metal Lbustion engines areaofquiteiintriciateand @requiredtftomairel up lfordzhe A o si Cylinder heads for liquid.- cooled 1 internal comf' numeroussubstantial1-variationsiin fthe crosssecfing ofthe-menen metalztharfthez'nw: mi

einem mmf-andthmughgthefmoid eavityfisotaiieniawfform andxevexfnature.itliat t'turf-in beamten:

eliminatedor pushed out-.ali d tu er.; oserei e the mold to the hotter portions of the mold andsubsequently to the external metal supplied for compensation of all the metal shrinkage that occurred in the casting.

A further object of the invention is to pro- -vlde a mold of the .character mentioned, which is vented to permit escape of gases arising from the sand core, so as to avoid blows which cause voids in the casting due to the trapping of suchl gases within the metal in the casting cavity.

When casting a hollow object by means of a permanent mold a frangible sand core is employed to forrn the chamber orr cavity within the casting. 'I'he core is subsequently removed in the- `usual manner after the metal has solidified or frozen. The use of a baked sand core in combination with a permanent mold gives rise to the' generation of gas in the sand core. caused by thel heat of the molten metal around and in contact with the sand core. Some ofthe core gas may Vbe generated at the surface of the sand core and.

unless themold is properly designed, commingles f. with'the molten metal to an objectional degree as the latter iiows over. thetcore in nllingthe casting cavity. .After the sand core is surrounded by the hot molten metal and during the solidiilcation of the latter, gas is usually generated internally ofthe core and unles's released builds up a considerable pressure therein. p In some inorstances such pressure is sufficient to force the gas through the solidifying or'partly molten metal even to the extent of blowing metal out the sprues and risers of the mold. Where the gas forces its way out of the core into the solidifying metal itcauses what is known as a blow hole. The resulting casting is either useless as such or of such e defective character that the advantages lexpected from the use of a permanent mold are" lost and no material advantage-is obtained over sand castings. 'I'he present inventionv aims to provide a .method and apparatus for making castings of aluminum and its alloys of intricate design, such ascylinder-heads; wherein provision is made for' the escape of core gas during the lling of the mold and while the molten metal is freezing and solidifying.

'A further object ofthe invention is to provide a mold for cylinder heads or the like which re- -uuires in the casting operation an amount of metal only slightly in excess of that required tov .i111 the casting cavity. A further object is to provide a mold of simple design'made up of a minimum number of parts fromwhich castings can be quicklyzand, easily removed and which can be quickly assembled for the casting operation.

With the above and other objects in`view.- which will become apparent as the ,descriptionproceeds ,the invention may be said to comprise a moldisuchas illustrated in the accompanying 7u drawings. hereinafter described and particularly .set'forth in the appended claims, together with such variations andmodiflcations thereof as will -be .apparent to one skilled in the art to which theinvention apprtains.

- l Il .Reference should be had to the accompanyingdrawings forming a part of this specification. in which: 'Y

Figure l is a front elevation of a 4permanent mold embodying the invention;

Fig. 2 is a side elevation of the mold; 5

Fig. 3 is a detail view partly in section and with parts removed, showing the latch for holdlngthe mold in various positions of adjustment taken substantially on the line 3-3 of Fig. 2;

.Fig`. 4 is a fragmentary transverse sectionlo y through the casting' cavity and sand core;

Fig. 5 is a section with parts removed taken substantially onthe line indicated at 5 5 of Fig. l;

Fig. 6 is a fragmentary side elevation with parts 15 `removed showing the mold in pouring position;

Fig. '7 is a fragmentary side elevation with parts removed showing the mold in inverted freezing position;

Fig. a is a 'section taken substantially on the 20 line indicated at 8-8 in Fig. 6, looking toward the bottom section of the mold;l

Fig. 9 is a section taken substantially on the line indicated at 9--9 in Fig. '1, looking toward the top section of the mold; 25 Y Fig. 10 is a-fragmentary transverse section with parts removed through the mold in freezing position and'taken substantially on the linel ill-I0 of Fig. 9;

Fig.. 11 -is a fragmentary longitudinal section 30 .showing the gate from the feeding cavity into the casting cavity and'taken substantially on the' line II-Il of Fig. 10;

Fig. l2 is a view'partly in section and with parts broken away. showing a slightly modified 35 form of mold and corresponding to Fig. 9 of the first mold illustrated. In this view, which is taken substantially along the line I2-I2 of Fig. l5, a portion of the top mold section is broken awayvto show the casting and feeding cavities and the sprue or pouring passages; .40 v

Fig. 13 is 'a longitudinal section taken substantially on the line-indicated at I3-I3 in Fig .`,12;

Fig. 14 shows the mold of Figs. 12 and 13 in pouring position with parts broken away;'

Fig. 15 is a section with parts removed taken 45 substantially on the lineindicated at IB-'IS in Fig. 12 and enlarged with respect thereto, andV show-ing the mold in freezing position: v

- Fig. 16 is a diagrammatic illustration showing al modincauon of. the invention, in which the feed- 5 ing cavity is annular in extent and extends com pletely around lthe periphery of the casting cavity;

Fig. 17is a sectional view taken substantially on the line I'I--ll of'FlS. 16;- l

Fig. ,18 is a diagrammatic illustration of amodiilcation of the invention, in which the feeding cavity 'extends on three sides of the casting' Y cavity and receives molten metal from supplementary pouring passagesjor sprues; `50

' Fig'. 19 is a sectional view taken substantiallyy Fig. 20 is a diagrammatic'illustration of a modiflcationl of theinvention, in which an overflow on the line 2|-2I of Flg..20; and

Fig. 22 is a sectional view taken substantially 7 0 on thev line 22-12 of Fig. 2D. showingfa modified- -type of gate 'through which the molten :metallf y flows from'tlr'e pouring passage into the feeding cavity.

' A mold const ructevily inaccordance with there' present invention is mounted for pivotal or turning movement froml a pouring position to an inverted freezing position, applying the principle of the vinvention disclosed in my Patent No. 1,982,424 granted November 27, 1934 to molds for the casting of cylinder heads. for motor vehicle engines or other castings of similar form.

As shown in the accompanying drawings, in' which like parts throughout the 'several views are indicated by the same numerals of reference, the mold of the present linvention is rotatablysupported upon a pair of spaced upright standards I and 2 by means of

horizontal trunnions

3 and 4 journaled in the tops of the standards and extending from brackets 5 which are attached by means of bolts 6 to the opposite ends of bottom section 1 ofthe mold. l'I'he trunnion 4 extends beyond the journal in the standard 2 and is provided with angularly spaced radially extending

arms

8, 9, and iii, which are adapted to be successively engaged by a latch H carried by the adjacent standard 2 near the bottom thereof. The

arms

8, 9, and I may be used to rotate the mold and when successively engaged by the latch Il hold the mold in the three positions which it occupies during operation. The arm o when engaged by the latch il holds the mold in assem bling position, as shown in Figs. l and 2.. The arm 9 holds the mold in pouring position as shown in Fig. 6, and the arm I0 holds the mold in freezing position as shown in Fig. 7@ The -latch I I is a notched nar connected to the standard. 2 by a vertical pivotv I4 and is urged outward. ly toward engaging Position by a spring I5. The latch Il is 'connectedby links I6 and i1 and a bell crank lever i8 to a treadle i9 so that when the treadle isdepressed the latch Il vis drawn inwardly against the spring I to releasing posi- ;*tion and the mold can be turned from one position to another during operation.

.A top mold section 20 is connected along its rear edge to the r'ear edge of the bottom section 1 by hinge bar 2|. 'I'he mold is held in closed position by means of clamps 22 connected by pivots 23 to the lower sections 1. The clamps 22 are of U-shape pivotedat one end and carrying screws adapted to be screwed down upon lugsv 25 procting from the front edge of the upper section The confronting or meeting faces of the mold sections are formed to cooperatively define i n elongated casting cavity having its long axis su stantially parallel tothe rotational axis of the trunnions`3l and 4.v The face of the upper mold section 20 has a recessed surface portion 21 which conformsto the configuration of the outer surface of the outside -or exposed part of the cylinder yhead to be cast. Face portion 28 of the bottom mold section 1 conforms to the conguration of the outside wall ofthe cylinder head and may be provided with metallic'corepads or chills 23 to vform the combustion chamber recesses in' the cylinder head which overlie the'cylinder of the engine. As shown in Fig. 4,'the casting cavity dened by the surfaces 21 and 2l`- and the pads 28 is formed primarily in the upper mold section 2l.

I'he meeting faces of the

mold sections

1 and 20 are fiat around .the margin of ythe casting cavity,forming a parting lin ably lies in a substantially horizontal plane along -the side and rear edges of -themold when the mold is in assembling position Along the front edge of the mold the meeting 24 at theirl free ends which are surface. of the compression- 30 which prefer- Asecured to the head 6| and ions 63 o'n a shaft 84 havingv an actuating handleY (Figs. 1 and 2).`

r tially throughout its length to provide a chamber for circulation of cooling liquid or water and has bolt receiving apertures 33. 'I'he apertures 33 are formed in bosses 34 which are integral with outer wall 35 and compression wall 36 of the cylinder headand extend transversely through the cooling liquid chamber ofthe head.

The casting is also provided with apertures 38 in thebottom or compression wall 35 through which communication is established between the interior or cooling liquid chamber of the cylinder head and the water jacket or jackets oi' the engine. .A sand core 33 is disposed in the casting cavity between the

surfaces

21 and 28 of the mold sections iii` and 1 respectively, and is shaped to conform to the desired interior cavity or cooling liquid chamber of the casting. sand core has apertures therethrough of a diameter corre- Spending to the external. diameter of the bosses 34 which form the tubular walls of the bolt apertures 33 within the cooling chamberof the head. The side of the core 39 toward the mold section 1 is provided with a number of recesses 4i) adapted to receive positioning pins lli which have reduced diameter and portions frictionally retained in drilled holes 42 `formed inthe face 28 of the mold section 1.

The lower section 1 of the mold carries a series of slidably mounted core pins 44 which are adapted to vbe projected through 'holes in the cavity face 26 substantially entirely across the mold cavity, centrally ofthe openings in the sand core which delne the bosses 34, thus serving to form the apertures 33 through the head. Another series of core pins 45 slidably mounted in the lower section 1 are adapted to be projected through the face 28 of the mold section into the casting cavity a distance corresponding to the thickness `of the bottom or compression wall V36 of the casting and into abutting engagement with the sand core to serve as supports for the latterand to define the cooling liquid inlets 33. Suitable chaplets-46 may he provided and are received in spaced holes 41 inlthe face 21 of thev Beneath thebottom section 1 there are mount-l ed a first pair of

movable heads

48 and 49 disposed in end to end relation and each extending' yone-half the length of the casting cavity.: To

these headsare attached the core pins. Racks' 50 and 5|, attached to the bottoms of the heads 4'8 and- 49 land projecting at right angles thereto,

are'engaged by pinions 52 and.53, respectively, on

shafts

54 and 55 which are operated by' means of handles 56 and 51.

Surrounding the knockout pins or sleeves 60 which'are attached at their lower ends to a head 6l. Racks 62 are are engaged by `pin- AThe pin supporting heads and .their actuating racks are mounted in a housing i1 secured to the core pins 4 4 and slidable in l apertures 59 initialeA bottom section 1 are tubular Y under side of the mold section 1. The

heads

48, 49, and 6| are guided by the-rack bars in the housing 61 and are movable toward and away from the mold section 1 by means of the racks and pinions actuated by the

handles

56, 61, and 65, respectively. Stops 66 secured to the housing 61 engage the heads to limit the movement there- The heads 46 and V49 seat against tl'iev stops 68 when the core pins are fully projected into the casting cavity, substantially in the position shown in Fig. 4. 'I'he stops engage the head 6I when the ejector sleeves or hollow pins 60 are flush with the surface 26 of the casting cavity.

After each casting operation, the handles 66 and 51 may be actuated to withdraw the pins 44and then the handle 65 may be actuated to free the casting from the bottom mold section after the mold is opened.

Along the rear edge of the casting cavity the meeting faces of the mold sections are recessed to provide a feeder cavity 10 which preferably is connected throughout substantially its length with a relatively narrow ingate 1i, as shown in Fig. 1l, the cross-sectional area of the ingate being enlarged at intervals along the length thereof as shown at 12 to provide freery 'flow of metal into portions of the casting adjacent the bosses 34 which are located near vthe marginal edge of the casting. 'I'he increased flow of hot metal around the marginal core pins induced hy Athe enlarged gate portion retards the freezing oi the adjacent portions of the casting and pro- I. motes. a more uniform freezing o f lthe metal .across substantially the entire length of the castvfrom said feeding cavity freeze.

ing. It is important that the freezing of the 'molten metal initiates at the side of the casting remote from the feeding cavity 10 and progresses relatively uniformly across the width of the casting toward the feeding cavity. In this manner. as crystallization shrinkage occurs, molten metal is fed into the casting cavity through the ingate 1I from the vbody ofmolten metal in the feeding cavity 10. The provision of an increased flow of hot Ametal. by means of theincreased varea vingate portions 'I2 through those'portions of Ithe casting cavity wherein freezing normallyv starts and occurs at a relatively rapid rate, tendsto reduce such early freezing and delay the freezing of the metal along the edge of the casting cavity adjacent the feeding cavity 1l. until the portions of the metal in the casting cavity more remote Accordingly, entrapment of bodies or portions of vmolten metal inthe interior of the casting cavity,'by premature freezing of marginal .portions of the casting.

Recesses are formed inthe meeting'faces of the mold sections to definepouring passages or sprues 13 and. which extend from inlet openings 16 in the parting line 3| at the front edge of the mold along opposite ends of the casting cavity beyond the feeding cavity 16. Along the rear edge of the -mold the ends 16 vof the pouring sprues are joined by a connecting passage or ""sprue11 which substantially parallels the feeding cavity 16 on the opposite side thereof froml the casting cavity and is. formed by mating recesses in the meeting faces of the moldsectio'n. The

passage4 11. is connected to the feeding cavity 16 at intervalsby suitable end gate apertures 16 and central lgate apertures 16. 'As shown -in Fig. 9, the apertures or gates Il which provide'the inlets from the connecting sprue passage 11 to the feeding cavity 'Il adjacent the central portion of the e 11 are spaced closer together than the end gate'passage 16 to provide for ow into the through the ingate enlargements 'l2 which effects a somewhat lateral flow of the metal in the casting cavity above these points of ingress towards both ends of the cavity. 1

In operation the mold previously heated to the proper temperature and with the casting cavity. surfaces suitably treated with dope inthe usualmanner, is first placed in assembling or rst posi- '.tionwith the upper section raised as shown in dotted lines in Fig. 2. The handles 66 and 61 are operated to raise the heads 46 and 49 to their uppermost positions to project the core. pins through the buttom vsection 1. The. handle 66 is operated to retract the ejector sleeves 66 and the core positioning pins 4-I are set in the holes 42 in the bottom. mold section. The sand core 39 is then placed onthe section 1 upon the tops of the supporting core pins'146-with the positioning pins 4l projecting into the recesses 40 thereof sol and the core pins 44 projecting centrally through the apertures 43 of the sand core. The chaplets 46 are positionedv in the holes 41 of the top mold section 20 and the latter is then swung to closed position and locked by means of the clamping screwsj24.

A network or maze of interconnecting passages 60 are provided internally of the sand 'core I! and communicate with the atmosphere through ll 40.

passages 6i. and 62 formed in the supportingcore pins 45 and positioning pins 4I. In this manner,

core gas generated in the core 39 during the casting operation and while the aluminum metal is solidifying, is permitted to escape freely from within the core. passing to the atmosphere.,

through the passages 60 in the core land the passages 6| and 62 in the core SuPPOrting members. Thus is prevented the building up of a pressure of core gas within the core which-would otherwise be apt to force itself through the molten or vsolidifying metal 'andcause a misrun or other imperfect casting. The-latch Il is released and. I.

the closed mold is moved to seconder pouring position, shown in Fig. 6. In this position ofthe mold the pouring

passages

18 and 14 have their open or inlet ends 16 up, and the connecting passage 11 and feeding cavity 1 6 are wholly below thev casting cavity.

Twooperators, one at each end of the mold,

' pour metal from ladies into the inlets 16 of the sprue es Il and 14.

This pouring is continued until the lever q1 the molten metal rises to the top of thepouring'passages. The molten metalftlows down the passages 13 `and 14, into .the connecting sprue passage 11, through the openings 1I .and .18, upwardly into` the feeding cavity 16 and then upwardly through the gate 1l into the casting-cavity. The molten metal rises uniformly vin the'casting cavity through the passages around the core members until the casting cavity is filled completely. The reversal of direc-4 tion of flow priorfto entry into the feeding cavity 1l and the mold or casting cavity and therest-rictionof the inlet toward the ends ofthe feeding cavity insures the filling of the

passage

11 and 7| cavity l0 prior :to fcllllr` of metal into `the casting cavity of the moldso 'that turbulence is quieted prior to fiow into the mold `and ow into the mold "eavitv Vis governed solelyl by hydrostatic` 5 pressure,` the crosvs-seetional area of the passages being such that-the level 'or the molten metal in Vthepourlng passages'and "I4 rises' substantially mold' A cavity."

in @he on opposite sides of the same core at substantially l 'a uniform even rate so as to meet one another at substantially the parting line 3lv which is uppermost during the pouring operation. Thus is prevented the ow of` metal thrllughv thethick section portion of the ,'casting cavity atarfaster ,.7 ereofe lvopposiv I ratethanthrough the section portion so that the; lspilling of; metalk vover* the-upperm0SLedge vtlf the sl l4:1` core from one side thereof to the y,other isavoded. l v f f l f; "5 Aixvvzhich isrdisplaced by the inolning metal .fis fc'lrcedwcvlut.ofV the casting cavity*throughv4 a. mul.- r 'tiplicitykovf' ,relatively ine lvent `grooves formed e fue? 0I eneofthefmoldsections :allons-fthey e l' I.

' hefe'edingI cavity 11|lfand;

In Figures 12` to 14 the invention is shown applied to a mold for casting a cylinder head of the straight-eight type. In this adaptation of the invention bottom section 85 of the mold has a cavity denning surface' 81 which conforms to the top and side and end faces of the head. Face 88 of top section 88 is shapedI to conform to the base o'f the head. A sand core 98 is positioned within the mold cavity between .the

faces

81 and 88. The bottom section 85 carries retractable corepins 9| and ejector sleeves 89 which serve the same purpose and correspond to, the core pins and

ejector sleeves

44 and 68, respectively, in the mold nrst described. In thismodincation, however, the core pins are provided only for stud bosses 82 and l88 which are remote from feeding cavity 9 1 and stud bosses 94 adjacent the feeding cavity are without core pins. Members 85 on the bottom vmold section 85 form depressions in the top of the cylinder head casting for receiving the spark plugs of the engine. Retractable core pins 98 movable through' the mold portions 95 form the apertures in the castingl for the spark plugs.

The feeding cavity 81 extends the full length of thecasting cavity along one edge thereof and feeds through continuous ingate 88 upwardly into the casting cavity during pouring, with the mold intoja recess |8| in the sand core and the-sand core may be provided with passages |82 to con- 40 section 85.. The member |89 is arranged to form l 45 supported in the inclined pouring position shownv in- Fig. 14. The ingate 88 is widened at 89 opposite each of the thick sectioned portions 1 of the casting cavitywhich form the solid stud bosses 94. .The pouring passages and connecting passage are similar to those described in connection with Figs. 1 through 11.

- As shown in Fig. 15, one or more tubular core members |88 may be provided 4for venting the sand core 88. The core member |88 extends duct gases to the outlet provided by the tubular core member.v Preferably, one of the ltubular core venting members |88 extends through a' memberv |89 secured in an aperture of the mold water outlet passage ||8 of the cylinder head.

As shown in Fig. 14 and Fig. 15, the ingate 88 opens into the casting cavity at the side thereof whichforms the relativelythick base portion of the casting. The inclination of the mold in the 'pouring position, Fig. 14, is such as to favor flow through the thinner passages of the casting cav- 4- ity, and as shown 1n Fig., 15, the inclination 0f the mold in the freezing position is such as to favor'now to the thicker .portions oi' the casting.

illustrated `modifications of the invention. y In these ngures the modications havebeen shown as applied to l a-moldfor casting acylinder head- In Figs. 16 through 22 arediagrammatically of the character illustrated'in'Flgs. 1 through 11. It is to be understood, however, that these variations or modifications can be adaptedto'other cylinder heads such as the cylinder heads shown ln 12 through 15.

In rig. 15 me feeding cavity is shown as being of annular extent and is disposed around the perlpheal V'edges of the relativelyn'at casting f cavity. Inthe casting operation the molten metal is poured into the inlets 15 of the pouring

sprues

18 and 14, flowing downwardly therein-v between the meeting faces of the' mold and thence into the horizontally disposed connecting sprue or passage 11. The molten metal then rises or flows upwardly through the

gates

18 and 18 into receiving portion |88 of the lfeeding cavity, which extends substantially horizontallyll and is attains located between the-connecting passage '|1 and the casting cavity. While the mold is in pouring position the receiving portion |88 is the lowerfeeding `cavity, which extends along the side ofthe casting cavity opposite the receiving portion |83 and in parallel' relation therewith. As the molten metal rises in the casting cavity, the end portions |85 of the feeding cavity receive molten metal from the ends of the portion |88. Metal fromthe end portions |85 flows laterally into the casting cavity through substantially continuous gates |81 (Fig. 17). If desired, the gates |81 may be continuous with the gate |84 around the entire bottom and side edges'of the casting cavity to promote a more uniform iiow of metal into the lcavity during the' pouring operatiomi H owever, for practical purposes in connection with the machining and nishing of the casting, lit is preferable that the corners of the casting cavity `be blockedo as indicated at |88, so that at these pointsV thefeeding cavity does not communicate with the casting cavity.

Between the uppermost edge ofthe castin cavity and the lportion |88 of the feeding cavity there is no ingate. The feeding cavity portion |89 carries heat to the portions of the mold remote fromthe receiving portion |88 of the feedingvcavity and in this manner tends to equalizel the temperature of the mold and to promote 'Ta more uniform and even freezing of the metal in vthe casting cavity when such is desired. The

portions |88', |85, andI |88 offthe feeding cavity shownv in Fig. 16'are of substantially uniform cross-sectional area around the entire periphery of the casting cavity. It is to be understood,-

however, that the' cross-sectional area may be suitably varied to produce the desired heating effect on the several portions ofthe mold.

Iig. 18v illustrates a modification-of the inven.

tion in` which the feeding cavityhas a substan tially horizontal receiving portion |I8 disposedthe casting cavity. End portions of the feeding cavity are continuous with the receiving porbetween the connecting passage or sprue11 and i I tion ||'8--and-extendacross-opposite ends'of the'v -1 casting cavity. A substantially continuous in' gate-| I2 corresponding to the ingates 1| and |84,

previously described, connects the receiving vportion ||8 of the feeding cavity with .the 'casting lcavity. Ingates I8 (Fig. 19) which correspond to ingates |81 shown in Figs. 16 and 1 7,.connect the opposite ends ofthe casting cavity. In this modincation the pouring

sprues

18 and 14 are cient distance to provideroom for sprues 4 which extend in substantially parallel relation to the pouring spruesbetween the latter and the end, portions of the i'eedingcavity'. One end of each of the sprues 4 communicates with the connecting passage or sprue 11 adjacent one oi' the ends 18 of the latter and the opposite end of each ofv the sprues V||4v is closed to prevent the discharge of metal ltherefrom upon inverting the the end portions In of the ,feeding cavitywitn' spaced from the endsoi the casting cavity asuiii- 2,233,405 mold tofreezing position. A pluralityv of Ashort l! and the fillingV of @the :casting cavity` is commence'zi,r molten metaljslfedinto'the end p0rtionsfi-H oftheicasting,cavitythrough the sprues M and l|'I 5 without-mst owing'through the receivingor ,horizontal portion Ilv ofthe feeding cavity. Thus-it, may be'saidsthat after-the filling of the castingtcavityffthrougnfthe bottom has commenced, v-metal fisffshortf-circliited into the. feeding vv,ca.vity.1and toasting-cavity through". ythe f i sprues, H4, andmlilvxand ;thefzendfxfeedingfcavity I I |,";a.l1'- of.fwhich:-.-areaformedi=in the-.me'eting faces i- `of the mold .-sections' .Excessiverheating of the portionsrofx theamoldaadjacentitherfreceiving por#y l rtion; M offthesfeedingfcavityis thus'favoided i that all portionsaofrthefimoldtarfmaintained'@at:

morefnearl uniformitempratures- Upon invertingmffthefsmoldifgatedias shown Fig:21:18frthe:.moltenametalrisritrappedwithin th' acastingfcavityianchzfeedinm avityrbysclosedffend .l1

| |stofJanneman-campane:- on

wun'rig 1a tiomwithaan: overowrchambe I opposite the receivingmortiont i (Fig. 0, he

gasifzort'zboth riedtupwr'di rby nefnowing mtaliintostne ver- 'Rurefrnetalu-free ifi-omocclutied xgases and 'anni` 2 may" l to be lunderstood that the invention is also apcavity: shownuiamg. .'20 communicategprwithg-.me

whichie'xtendsfi-.entirely portions t|l;andi:|-|trespectively; .the-f-feedi1"1g.'.l cavity-.5. feedingzcavityais intcontinuo'us i through which the metal is introduced into the. mold, while the gates more widely spaced are adjacent the pouring sprue. i flowof metal into the feeding cavity is regulated l so as to be substantially uniform throughout the A entire length of the feeding cavity. 'I'hus the flow vf thrash;

a creases. I t

cavity is regulated so as to at a substantially uniform rate throughout its entire length. The

relatively narrow end portions |28 of the slot |25 tend to retard the flow of metal from the ends of may be employed as an alternative to the gates 1-8 and 19 forproducing the desired uniform upward flow of molten metal into the feeding cavity and casting cavity.

It is to be noted that in Figs. 16 and 20 while the feeding cavity is shown as extending across the lower side and ends lof the casting cavity when the mold is in pouring position, all of the metal flowing into the casting cavity must enter through the receiving portion of theY feeding cavity which is disposed along the lowermost side of the .casting cavity, the metal thus dividing in The invention has been illustrated as applied to the casting of cylinder heads for automobile engines. It is .to be understood, however, that amount of metal to compensate for crystallization shrinkage. It should be noted that very little metal is required for the sprues, a portion of the excess metal being returned to the ladle upon inversion of the mold. The parting lines are along the side edges of the casting so 'that the l ksmooth surface provided by freezing against metal extends throughout the top and bottom of sand.ontheikezfromthe-core and-"als airo core-lf the casting.

While the invention has been illustrated and explained as exmpliiied in a 'mold into which metal is poured by two men who simultaneously feed the molten aluminum from the ladles into the pouring sprues or

passages

13 and 14, it is plicable to molds havingbut a single pouring sprue. For example, in the molds illustrated in the drawings, castings can be satisfactorily produced by the filling of themold from a single ladle,`the operator pouring the entire quantity' required for lling the mold through either the pouring spruev13 or the pouring sprue 14. It is desirable, however. in such cases to modify the gates -18 and. 'I9 so that the relatively closely spaced gates are remote from the pouring sprue In this manner the pour .a continuous gate, such as shown at |25 in Figs. 20 and 22, is employed, the narrow end of the gate will be disposed adjacent the single pouring sprue and the gate will widen progressively as the distance from the pouring sprue in- In all of the embodimentsof the invention the flow of the molten metal into the casting cavity is such that it rises therein at a uniform rate in all portions so that thel air and gases in the casting the feeding-cavity to iiow up the opposite end portions thereof.

the present inventionis applicable to the casting j of various articles -with or without sand cores in which non-uniform cross-section of the casting f along the length thereof requires a considerable bere'extendsiaiongsthesedgesfof the xaatsizixng-'Jcavity*v f 0 ofith lfeedin "'g rcavity anch communicates witlthe'ica'stiiig' cavitytirefienstnztlirqugn-f l cavity are forced out ahead of the metal. Thus if gas is liberated or released from the sand core upon initial contact of the molten metal therewith, s uch core gas mingles with the air in the mold cavity and rises upwardly and is forced out s of the mold by the incoming metal, there being a minimum opportunity for entrapment of the core gas by the casting metal.

Furthermore, it isto be understood that the particular forms of apparatus shown and described, and the particular procedures-set forth,

are presented-for purposes ofexpianation and illustration and that various modifications and substitutions are contemplated and can be mad without departing from my invention.

What I claimis:

l'. The method of castingelongated aluminum alloy cylinder. heads or the lille in a permanent mold which comprises positioning the mold with thel casting, cavity extending horizontally and v with the-side edgesof thev cavity at the top and bottom, fillingl the. cavity' by causing molten metal to .flow upwardly from' belowthe casting cavity into the' lower longitudinal edge of the cavity substantially throughout the length thereof, turning the mold to a freezing position in which the longitudinal yedge of the casting cavity through which the metal entered is uppermost, and compensating. for shinkage of the metal during freezing by.feeding metal downwardly from above thecavity through said longitudinal edge substantiallythroughout the length thereof.

2. The method of casting a hollow elongated aluminum alloy head for a multiple cylinder en- 1` gine in a permanent mold having separable sections .with meeting faces. recessed to provide a cavity` conforming' to the exterior of said head, which comprises assembling the mold with a sand vcorev which conforms'to the interior of the head in said casting cavity, positioningthe mold with a longitudinal/edge of the casting cavity 1ower most andA substantially horizontal, -lling said,

cavity with the 'mold so positioned by causing molten metal' to' now upwardly into the casting,

cavity along said lowermost longitudinal edge. reversing the position of the mold with to a-horizontal axis and subsequently feeding metal downwardly into the uppermost edge portion of the 'casting cavity along substantially thev full length thereof during freeaing to compensate for.

shrinkage in' the casting.

3. 'Ihe methodl of casting 4a hollow elongated aluminum alloy head' for a multiple cylinder engine in a permanent mold having separable sections with meeting faces recessed to provide a cavityA conforming to the menor, of said head." which comprises'assembling the mold with a.

sand core which conforms tothe interior of the head in said .casting cavity, in apos'ition topto- -vide' the casting with a base wall thicker the side and top walls thereof, positioning the mold-with aV longitudinal corner at the juncture of the base-and sidewall forming-portions of the castingcavity rlowermoist and substantially horlzontal,.' and with thev base forming wall of the casting cavity inclined tol the vertical `and partially overlying the casting cavity, filling the casting vcavity by causing 'molten metal to now upwardly into the casting cavity along said longitudinal comer, shifting the mold angularlywith respect to a'horizontal yaxis to bring the base of the casting to a position inclined to the vertical .and partially underlying the casting cavity, and feeding metal downwardly into the base of the casting along substantially the full length thereof during freezing to compensate for shrinkage in the casting.

4. The method' of casting a hollow elongated -aluminum alloy head for a multiple cylinder enf ing molten metal upwardly intoth'e casting cavity substantially simuitaneously and Vuniformly along substantially. the entirelength -of said lowermost longitudinal edge andsubsequently feeding metal downwardly into the uppermost por' tion of the casting cavity along substantially the full length 0f said edge during freezing t0 60mpensate for shrinkage' in the casting.

5. The method of casting elongated aluminum valloy articles of non-uniform cross-sectionalform in the casting cavity of a'permanent mold which comprises, supporting the mold with 'a ldngltudinal edgeof the casting cavity lowermost, dllinto the cavity along substantially the full length ing the mold cavity by feeding metal upwardly Y of said lowermost edge, reversing the mold to',

' bring said edge throughwhich metal is fed to an uppermost position, supplying metal through'4 said edge in uppermost position tccompensate for shrinkage in the casting, and chillingl thick portionsoi the casting remote from said edgel through which metal is supplied to freeze the same before'the freezing-of portiom ofthe cast-l ingadlacentsaidedge'..

8; The method of casting an 'sides and ends thereof which integrally Join the meeting faces recessed. to provide a cavity conforming to the exterior of said head, which comprises assembling the mold with"v a sand core in the casting-cavity which has openings to'form the |integraljjoining portions of the casting, posi- ',tioning, .the moldl with il. longitudinal edge oi' the casting cavity lowermost and substantially horizontal, filling saidv cavity with the mold so positioned by causing molten metal4 to now upwardly into the cavity along said longitudinal edge, reversing the mold'to bring ald longitudl- .nal edge from lowermost to uppermostposition.

chilling the integral joining portions of the casting which are remote from the longitudinal edge into which the molten metalisfed more rapidlythanthe integral joining portions which are adjacent auch edge are chilledand supplying metal tothe cast- `ing cavity valong the upper edge thereof during aluminum alloy head for a multicylinder engine,- which is hollow` end of'elongated form having transversely and 40 longitudinally spaced portions intermediate the' base and top walls,- in a permanent mold having freezing to 'compensate for shrinkage in the casting.

'1. rhe method 'Messung an aluminum suoy head for a multlcylinder engine, which is hollow and of elongated form having a base'wall thicker than the side and top walls thereof and transversely and longitudinally spaced portions intermediate the sidesland ends thereof which in -v tegrall'y ioin the base .and top walls, in a permanent mold having meeting faces recessed to proa` a sand core in the casting cavity which is positionod in the casting cavity :provide a base wall vide a cavity conforming to the exterlorof said v head, which comprises assembling the mbld withthicker than the other walls of the casting and which has openings to form the integral joining -portions of the casting, positioning the mold with a longitudinal edge of the base forming wall of the casting cavity lowermost and substantially horlzonta1,\ lling said cavity with the mold so positioned by causing-molten metal to flow upwardly into the'cavityv along said longitudinal edge, reversing the mold to bring said longitudinal edge from lowermost to uppermost position, chilling the integral joining portions of the casting which lare remote from the longitudinal edge into which the molten metal is f ed more rapidly v than the integral joining portions which are adjacent such edge are ed,and supplying metal to the casting cavity along the upper edge thereof during freezing to compensate for shrinkage in the casting. i

8. A permanent mold for making aluminum alloy castings, comprising separable mold sections abutting face to face with continuous contact between marginal portions of abutting faces, said faces being recessed to provide a casting cavity, a feeding cavity and a pouring passage, said feeding cavity extending along one side of the casting cavity and communicating along its inner side with the casting cavity, said pouring passage .having a lportion which substantially' parallelsV the feeding cavity and communicates with longitudinally spaced portions of the feeding cavity only at the outer side thereof, said passage extending to the exterior of the mold in the direction of the openings ltherefrom to the feeding cavity, and means for supporting said mold to turn from a pouring position, in which said feeding cavity is lower than the casting cavity and the pouring passage feeds upwardly into the feeding cavity, to a reverse freezing position in which molten metal is trapped in said feeding cavity and can ow only into the casting cavity and molten metal in the pouring passage is discharged from the mold by gravity.

9. A permanent mold for making aluminum alloy castings, comprising separable mold sections abutting face to face with continuous con. tact between `marginal portions of abutting faces', said faces being recessed to provide a casting cavity, a feeding cavity and a pouring passage, said feeding cavity extending along one side of the casting cavity and communicating valong itsY inner side with the casting cavity, said pouring passage' having a portion which substantially -parallels the feeding cavity and communicates with longitudinally spaced portions of the feeding cavity only at the outer side thereof, said passage extending tothe exterior of the mold in the direction of the openings therefrom to the feeding cavity, means carried 'by the mold sections for supporting and positioning a sand core within said casting cavity, and means for supporting said mold to turn from a pouring position, in. which said feeding cavity is below the castingsaid feeding cavity extending along one side of the casting cavity and communicating along its inner side with the casting cavity, said pouring passagehaving a portion which substantially parallels the feeding cavity and mmunicates with longitudinally spaced portions of the feeding cavity only 'at the outer side thereof, said passage extending to the exterior of the vmold in the direction of the openings therefrom to the feeding cavity, means carried by the mold sections for supporting and positioning an apertured sand core 4within said casting cavity, a metal vcore carried by o-ne of said sections adapted to be positioned Within an aperture of the sand core, and means for supporting said mold to turn from a pouring position, in which said feeding cavity is below the casting cavity and thefpouring passage feeds upwardly into the feeding cavity, to a reverse freezing position in which-molten metal is trapped in said feeding cavityand can flow only into the casting cavity and molten-metal in the pouring passage is discharged from the mold by gravity.

11. A permanent mold comprising separable mold sections and having an elongated casting cavity, a feeding cavity extending substantially the full length of said casting cavity, a gate extending substantially the full length of the feeding cavity between the inner side thereof and the casting cavity, a pouring passage extending from the exterior of the mold laterally of the feeding cavity on the same side thereof as the casting cavity, said passage having a portion which extends in the same direction as the'feeding'cavity and communicates with longitudinally spaced portions of the feeding cavity, and means for supporting said mold to turn from a pouring position, in which the feeding cavity is below the casting cavity, to a position in which the feeding cavity'is above the casting cavity. l

12. A permanent mold comprising separable mold sections and having an elongated casting cavity of irregular contour with parts of thick section and part-s of thinv section, a feeding cavity extending substantially the full length ofv said casting cavity, a gate extending substantiallythe Athereof as the casting `cavity and communicating with the feeding cavity only at the outer side of the feeding cavity, and means for supporting said mold to turn from a pouring position inl which the feeding cavity is below the casting cavity to a position in which the feeding cavity is above the casting cavity.

13. A permanent mold for making aluminum alloy castings, comprising a pair of mold sections which have inner faces with marginal portions iormed for continuous contact and with recesses which provide a casting cavity, a feeding cavity and a pouring passage, said casting cavity being of elongatedform, said feeding cavity being alongside the casting cavity, extending substantially the full length of the casting cavity and communicating along its inner side with the casting cavity, said pouring passage having a portion which extends in the same direction as the feeding cavity and communicates with longitudinally spaced portions of the feeding cavity at the outer side thereof only, said passage extending to the exterior of the mold in the direction of the openings therefrom to the feeding cavity, and means for supporting said mold to turn from a pouring position in which molten metal ilows downwardly through the pouring passage upwardly into the feeding cavity and upwardly from the feeding cavity into the casting cavity to a reverse freezing position in which the feeding cavity feeds downwardly into the castin cavity. f

14. A permanent mold for making aluminum alloy castings, comprising a pair of mold sections which have inner faces with marginal portions formed for continuous Lcontact and with recesses which provide a castingcavity, a feeding cavity and a pouring passage, said casting cavity being of elongated form, said feeding cavity being alongside the casting cavity, extending substantially the full length of-the casting cavity and communicating along its inner side with the casting cavity, said pouring passage having a portion which extends in the same direction as the feeding cavity and communicates with longitudinally spaced portions of the feeding cavity at the outer side thereof only, said passage extending to the exterior of the mold in the direction of the openings therefrom to the feeding cavity, means cai'- ried by the mold for supporting and positioning an apertured sand core within said casting cavity, a metal core carried Iby one of vsaid sections adapted to be positioned within an aperture of the sand core, and means for supporting 'said mold to turn from a pouring position in 'which molten metal flows downwardly through the pouring passage, upwardlytinto the feeding cavity and upwardly from the feeding cavity into the casting cavity toa reverse freezing -position in which the feeding cavity feeds downwardly into.

the casting cavity.

l5. A permanent mold for casting hollow'cylinlder heads and the like of aluminum alloys and the like which comprises in combination metal m'old sections recessed to provide an elongated casting cavity, a frangible sand core shaped to conform to the desired interior water chamber of the head to be cast, said core4 having apertures extending therethrough 'and pin receiving re cesses, means for supporting and positioning the core in the cavity comprising positioning pins mounted in one of the mold sections and engaged inthe core recesses and supporting pins mounted inone of the mold sections and engaged with -the surface of the core, retractable core pins'- smaller than the'core apertures and arranged to extend across the casting cavity through said apertures, a feeding cavity along one edge of the casting cavity and substantially co-extensive in length therewith, a gate between the inner side of the feeding cavity and the casting cavity extending substantially throughout the length of one of the cavities, a pouring passage extending from lthe exterior of the mold vadjacent the side of the casting cavity opposite the feeding cavity, said passage havinga portion which communicates with the feeding cavity-along vthe length of the latter whereby metal flowing into the -feeding cavity from the pouring passage fills the feeding cavity substantially without longitudinal owof metal in the feeding cavity, and means for supporting the mold to turn from a pouring position in which the feeding cavity is belowthe casting cavity to a freezing position in which the feeding cavity is. above the casting cavity.

16. A permanent mold for casting aluminum alloy cylinder heads and the like comprising separa-ble mold sections having confronting faces recessed to provide an elongated casting cavity, a feeding cavity extending along one edge of the casting cavity substantially the full length thereof, and a pouring passage along the outer side of the feeding cavity substantially the full length thereof, gates through which said feeding cavity .communicates along its length v.with the casting cavity and' with the pouring passage, the crossv sectional area per'unit of length of the gate from the pouring passage to the feeding cavity progressively increasing in the direction of normal flow of metal in the pouring passage during lling of the casting cavity to provide substantially uniform ilow of metal into the feeding cavity along the length thereof.

17. Apparatus for making thin sectioned aluminum alloy castings and thev like having relatively large surface areas, comprising a supporting frame, metal mold sections mounted on the frame for pivotal movement about a substantially horizontal axis and formed to cooperatively providel an elongated relatively thin sectioned casting cavity, a pouring passage in the mold sections having an opening above the level of the cavity and through which molten metal may be introduced into .the mold, said passage extending downwardly from said opening to a region below land between the feeding chamber and the casting.

cavity whereby molten metal 'introduced into the moldv through said opening flows downwardly through the pouring passage, thence' upwardly into the said chamber substantially uniformly along the length thereof and through the feeding chamber and into-the casting cavity, and means for moving the mold sections about said axis to a position in which the feeding chamber is above the level of the cavity and the gate passage from the pouring passage is above the level of the.

feeding'chamber whereby metal introduced into the mold during the latter part of the pouring operation is trapped in the feeding chamber and iiofws downwardly by gravity into the casting cavity during freezing of the metal inthe mold to compensate for shrinkage of metal in the cavity.

18. A permanent mold for casting aluminum alloys and the like about a frangible core of sand or the like to lproduce hollow thin walled cast.

separable ings.. comprising, in combination,

metal mold sections mounted for rotation about a substantially horizontal axis and formed to cooperatively provide an. elongated. casting cavity' having metal walls, a frangible core supported in the cavity and spaced from the walls thereof lto deiine the shape of the article to be cast, means for holding the mold in` a pouring position in which one edge of the cavity is lowermost, a pouring passage in the mold having an opening above the cavitythrough which metal may be introduced into the mold, said passage extending downwardly from the opening to a region below said lowermostjedge and having a portion which extends under the casting cavity for the major parrot' the length of the latter, a. feeding cham-y ber in the mold in said region and between the casting cavity'and the lower portion-of the paslo! metal in the pool diminishes the turbulence sage, said chamber having a length several times its width and being approximately co-extensive inlength with the bottom edge 'of the cavity, gate passages between said portion of the pouring passage and the feeding chamber along the length of the latter and between the feeding chamber and the cavity, whereby molten metal introduced into the mold through said opening flows downwardly through the pouring passage, thence upwardly into the chamber along the length thereof and through the chamber and upwardly into the casting cavity, the metal entering the casting cavity dividing adjacent the lowermost edge to ow upwardly onopposite sides of the core, and means for moving the mold sections to a position in which the feeding chamber is above the cavity and metal from the feeding chamber flows by .gravityinto Ithe casting cavity to compensate for shrinkage therein during freezing.

19. A permanent mold for casting aluminum alloys and the like about a frangible core of sand or the like to produce hollow thin walled castings, comprising, in combination, separable metal mold sections formed to cooperatively provide a casting cavity having metal walls, a frangible core supported in the cavity and spaced from the walls thereof, said cavity being disposed so that a narrow edge thereof is lowermost and substantially horizontal, a pouring passage in the mold having an openingfwabove the cavity through which metal may be introduced into the mold, said passage extending l downwardly from the opening to'a region below said lowermost edge and having a horizontal portion under the casting cavity, a feeding chamber in the mold between the cavity and the horizontal passage portion, said chamber being subnstantially horizontal and approximately co-ex- -tensive in length with said lowermost edge of the cavity, and means connecting the chamber with the passage and cavity so that molten metal poured into the passage openingy ilows downwardly -below the cavity and chamber, then horizontally' and upwardly into the chamber'and from the chamber upwardly in a substantially vertical direction into`the casting cavity where the metal divides to ilow simultaneously up both sides vof the core while maintaining a substantially uniform level of the metal in the cavity from end to end thereof during the casting operation, substantially without horizontal flow of, metal in the casting cavity.

20. In the method of casting an elongated hollow lcylinder head, or the like, of a metal such as -an aluminum alloy by the use of a frangible rcoreI of sand or the-like in apermanent mold having a casting cavity with metal walls, the improvement which comprises, in combination, supporting the core in the cavity in generally spaced relation to the Walls thereof, positioning the mold so, that the longitudinal edges ofthe cavity are substantially horizontal and one edge is above the other, continuously conducting molten metal from above the cavity to a region below the cavity, accumulating a relatively large quantity of the conducted metal in a feeding pool of l iiow quieting volume below and approximately parallel to the lowermost edge of the cavity, and continuously introducing molten metal from said poolinto the cavity alongsaidlowermost edge of the latter at substantially the same rate as molof the conducted metal and the metal introduced into the cavity flows quietly in a generally ascending direction over opposite sides of the core while the rising surface of the metal in the cavity is maintained substantially level from end to end of the cavity.

2`1. In the method of casting an elongated hollow cylinder head, or the like, of a metal such as an aluminum alloy by the use of a frangible core of sand or the like in a permanent mold having a casting cavity with metal walls, the irnprovement which comprises, in combination, supporting the core in the cavity in generally spaced relation to the walls thereof, positioning the mold so that the longitudinal edges of the cavity are substantially horizontal and one edge is above the other, continuously conducting molten metal from above the cavity to a region below the cavity, accumulating a relatively large quantity of the conducted metal in a feeding pool of iiow quieting volume below and approximately parallel to the lowermost edge of the cavity, continuously introducing molten metal from said pool into the cavity along said lowermost edge of the latter at substantially the same rate as molten metal is conducted into the pool and substantially without longitudinal flow of the metal in the cavity, whereby the relatively large mass of metal in the pool diminishes the turbulence of the conducted metal and the metal introduced into the cavity flows quietly in a generally ascending direction over opposite sides of the core while the rising surface of the metal in the cavity is maintained substantially level from end to end of the cavity, and feeding molten metal from said pool into the cavity during freezing of the introduced metal to compensate for shrinkage.

. 22. The method of casting a hollow cylinder head, or the like, of a metal such as aluminum alloy, in a permanent mold having a casting cavity with metal walls, which comprises positioning a frangible core of sand or the like in the mold cavity in generally spaced relation to said walls, introducing molten metal substantially vertically into the cavity along one edge thereof and at such rates along the edge that the metalows evenly up both sides of the core substantially without-horizontal flow in the cavity in the direction of the length of said edge, whereby air in the vcavity and gas liberated from the surface of the core upon initial contact with the hot metal is forced upwardly and out the top of the mold by incoming metal, inverting the mold to position said edge uppermost, feeding additionalI metal is freezing to permit the escape of gas gen` erated within the core by the heat of the metal and thereby prevent liberation of the gas into the' freezing metal in the cavity.

' 23. A permanent mold lfor casting elongated objects of aluminum alloys comprising separable mold sections formed to provide an elongated casting cavity, a feeding cavity of relatively. large cross sectional area extending along one edge'cf the casting cavity, a pouring passage 'along' the sideY of the feeding cavity opposite the casting cavity, and gate means through which the feeding cavity communicates along its length with both the castingy cavity and the pouring passage, the gate,

means between the pouring passage' and the feeding cavity having an increasing effective cross sectional area from one end of the feeding cavity toward the center thereof to provide greater frictionalv resistance to the flow of metal into the feeding cavity at said end than at the central part thereof whereby moltenT metal entering the pouring passage adjacent said end tends to flow through the gate means in substantially equal quantities along the length of the feeding cavity. 24. A permanent mold for casting elongated objects of aluminum alloys'comprising separable vmold sections formed to provide an elongated casting cavity, a feeding cavity of relatively large cross sectional area extending along-one edge of the casting cavity, a pouring passage along the side of the feeding cavity opposite the casting cavity, gate means througlf which the feeding cavity communicates along itslength with both the casting cavity and the pouring passage,'the

effective cross sectional yarea per unit,.of length of the gate from the pouring passage to the feeding cavity progressively increasing in the direction of normal flow of metal in the pouring passage during lling of the casting cavity to provide substantially uniform flow of metal into the feeding cavity along the length thereof, and means mounting. the mold sections for facile shifting movement from a pouring position in which the feeding cavity is below the casting cavity to a freezing position in which the feeding cavity is above the casting cavity. n

25. A permanent mold for-castingelongated objects of aluminum alloys comprising separable 1 mold sections formed to provide an elongated casting cavity, a feeding cavity of relatively large cross sectional area extending along one edge of the casting cavity and along at least one end thereof, a pouring passage having a' portion which substantially parallels the part of the feeding cavitydisposedalong' the Aedge of the casting cavity, gate means connecting one side of the feeding cavity with longitudinally spaced portions of the casting cavity and another 'side ofthe feeding cavity with longitudinally spaced portions ofv the pouring passage, said passage extending in the direction of the gate means past the feedingcavity' and the casting cavity'to the exterior of the mold, and means forv supporting the mold sections for facile shifting movement from a pouring position in which the casting cavity isgenerally above the feeding cavity to a freezing position in which the casting cavity is generallybelow the feeding cavity.

f 26. 'A permanent mold for casting elongated objects of aluminum alloys. comprising separable mold sections formed to -provide a horizontally elongated casting cavity, a feeding cavity of relay vtively large cross sectional area extending along the bottom edge of the casting cavity, a pouring passage extending from the exterior of the mold above the casting cavity to below the feeding cavity, gate means connecting the feeding cavity with the 'casting cavity above along its length 4 and with the pouring passagebelow, and. means supportingthe mold sections for facile shifting shrinkage loss in the'metal casting.

EVERE'I'r carAHLMAN.'l