US2932070A - Mold for casting complex annular shapes - Google Patents

Description

April 12, 1960 s. w. JACKSON ET AL 2,932,070

MOLD FOR CASTING COMPLEX ANNULAR SHAPES Filed Feb. 25, 1957 5 Sheets-Sheet 1 INVENTORS Siduqy W Jackson,

, Everett G. Fahlman ATTORNEYS April 1 1960 5. W1 JAcKsoN ET AL 2,932,070

MOLD FOR CASTING COMPLEX ANNULAR SHAPES Filed Feb. 25, 1957 5 Sheets-Sheet 2 52 I Everett G-Fwhlman BY 6W y W ATTORNEYS April 12, 1960 s. w. JACKSON ET AL 2, 3

MOLD FOR CASTING COMPLEX ANNULAR SHAPES Filed Feb. 25. 1957 40 42 40 Fig. 5

INVENTORS Sidney Jackson 7' 7 Everett G- Fahlman BY 6mm P ATTORNEYS 5 Sheets-Sheet a April 12, 1960 s. w. JACKSON ET AL 2,

MOLD FOR CASTING COMPLEX ANNULAR SHAPES 5 Sheets-Sheet 4 Filed Feb. 25, 1957 INVENTORS W Jackson 6- Fahlman Sidney Eve ett BY 4 .4w M

ATTORNEYS April 1960 s. w. JACKSON ET AL 2,932,070

MOLD FOR CASTING COMPLEX ANNULAR SHAPES Filed Feb. 25, 1957 5 Sheets-Sheet 5 Mp W ATTORN EYS United States Patent 15 Claims. (Cl. 22-138) This invention relates to permanent mold means for casting light metals, such as aluminum alloys and the like, and particularly'to means for casting light metals in annular shapes, such as truck wheels and the like.

The obvious advantages of using permanent molds rather than sand molds or the like have led to attempts in the art to increase the variety of shapes which can be cast in permanent molds;

One of the problems in connection with the use of permanent molds for light metal, castings of complex form results from the fact that, due to the rapid freezing or solidification of the molten metal in the mold, it is difficult to flow the metal into the mold cavity in such a manner that defects in castings are not formed by reason of imperfect filling of the mold on account of blocking of parts of the cavity by freezing metal.

A prime diiliculty in connection with the use of perinanent molds for making light-metal castings of intricate design and non-uniform cross-sectional form is the chilling effect of themold sections on the. cast metal.

The relatively faster freezing or solidifying of the aluminum or like alloy in a metal or permanent mold makes it difficult to flow the metal into the mold in such a manner as to prevent voids or other types of misrun, by reason of the imperfect; filling of the mold on account oftrapped air or the blocking of parts of the mold cavity by premature freezing of the casting metal. Castings of intricate design which have metal sections of different thicknesses tend to cause uneven heating of the various sections or parts of the mold, and this uneven heating of the mold sections aggravates the diificulty of properly introducing the metal into the mold without inisruns and premature freezing.

Another problem to be overcome in the casting of intricate designs having portions of difierentthickness is the elimination of surface depressions andinternal voids. The high crystallization shrinkage of aluminum and its alloysresult s in the drawing of molten metal to the relatively. thin, faster-freezing portions from the heavier or thicker sections of the casting, which, because of their higher heat content, freeze or solidify more slowly than the thin sections. Accordingly, when the solidification of the thick or heavy portions of the casting takes place, there is insufiicient metal to completely fill the cavity and the deficiency is made up either by surface depressions or sinks or by internal voids. In either, case, the casting is unsound and of decreased strength.

A principal object of the 'presentinvention istomeet the above problems in the casting: oflightmetals into shapes which are axiallyvreeentrant, such ascertain annular shapes.

Another object J of ;the: vinventiorris; to; meet the above problems-in the permanent-mold; casting-:01? lighi metals intoshapes which are bothv axiallyand radially re. entrant.

Another object of I the], invention is; to .provide jmeans tormakeiannulartpermanentzmoldrcastingsrotlight metals,

Fr A

' 2 in such a way as to minimize the machining required to remove excess metal.

Another object of the invention is to provide means to make annular permanent-mold castings of light metals 7 which are of higher quality than those heretofore provided.

Another object of the invention is to provide mold means to make annular castings of light metals, all of the major components of which mold means are permanent, including cores and the like.

Another object of the invention is to provide s'prues or pouring passage's'and a feeding cavity which may be structurally temporarily disassociated from each other after pouring of the metal and before removal of the formed casting from the apparatus.

Another object of the invention is to provide apparatus for casting annular shapes of light metal such as truck wheels and the like at a lower unit cost than has here'- tofore, been possible. 7

Another object of the invention is to provide mold apparatus having cap and core sections which are axially removable relative to each other and having side sections which remove outwardly laterally (i.e., radially with respect to the annular shape or the like which is to be cast).

Another object of the invention is to provide mold apparatus having cap and core sections which are axially removable relative to each other, the core section including subsections which remove inwardly laterally (i.e., radially) and the apparatus also having side sections which remove outwardly laterally (i.e., radially).

These and other objects and advantages of the irrvention will become more fully apparent from the fol" lowing description of one example of means embodyin'g the invention. In the accompanying drawings:

Figure l is an elevation of apparatus embodying the A invention, the apparatus being shown in freezing position with solid lines.

Figure 2 is a plan view of the'apparatus shown in Figure .1, with the overhead frame of Figure 1 omitted for greater clarity.

Figure 3 is an elevational view of sprue-definingimeans associated with the apparatus.

Figure 4 is a section on an enlarged scale' taken on line 4-4 in Figure 3.

Figure 5 is a section, partly broken away, taken on line 5-5 in Figure 2.

. Figure 6' is a' plan view of Figure 3 and further illusitrating the sprue-defining means which is the subject'of Figure 3 in association with the cap section of the illus} trated apparatus.

Figure 7 is an end view on an enlargedscale of'th'e sprue-defining means.

Figure 8 is a' view similar to the, central portionsof the plan view shown in Figure 2 with the sprue-definin'g' means cap section and side sections'removed.

Figure 9 is a section taken on line 99 in Figure 8, elements in addition to those elements shown in Figure 8 being shown in Figure 9.

Figure 10 is a sectional view" similar to Figure 9bu't showing the core in withdrawn or retracted position;

Figure '11 isa sectional 'view similar toFigure 10 but being taken ona plane normal to the plane o f'Figure lof Figure 11 also shows the core in withdrawn or retracted position;

Figure 12 is an elevation of apparatus embodying the invention, the apparatus being shown in pouring position and the view being taken from a direction normal totlie direction from which the view of Figure lis taken.

. Figures .13. and. 14. areenlarged detail views takenztnt-v lines,13-.--13 and 1 4-.1.4,' ,respectively,.in Figure.-12.-

Figure 15 is a partially diagrammatic view of an article cast in the illustrated apparatus.

In order to facilitate and condense description of the invention, the following references to the drawings will utilize reference numerals for the various parts and in parentheses will specify the number of the figure or figures of the drawings in which such reference numerals may be found. For example, cam skirt 41(9-12) signifies that the particular part referred to is given in the reference numeral 41 and is to be conveniently found in Figures 9 through 12, inclusive.

An article which may be formed according to the presentinvention is an annular wheel casting generally indicated at 80(15). It will be seen that this casting includes an axially re-entrant (i.e. doubling back on the structure :as a whole along an axial direction) flange encompassing alone A from which mold structure cannot be laterally withdrawn. The casing 80 also involves a laterally re-entrant (i.e. doubling back on the structure as a whole along a lateral or radial direction) boss which overhangs or undercuts a small zone B from which mold structure cannot be withdrawn axially.

Molds having collapsing permanent cores have heretofore been provided, but it will be appreciated by those familiar with the art of permanent mold casting that it has never heretofore been possible to cast annular shapes and the like which are both axially and radially re-entrant in the sense of the above description. I

Apparatus contemplated by the present invention and illustrated in the drawings includes a mold generally indicated at 10(1, 2, 12). The mold 10 is made up of a plurality of mold sections including a cap section 11(1, 2, 9, 12) and side sections 12(1, 2), 13(1, 2, 12), 14(2, 12) and 15(2). The -mold 10 also includes a core section generally indicated at 16(1, 9-12). Releasably associated with the cap section 11 in a manner to ,be described below is a sprue-defining means generally ,indicatedat 17(1-4, 6, 7. 12).

The several mold sections define a casting cavity 20(12) and a feeding cavity 21(12). The sprue-defining means 17 includes a sprue passage 22(3, 4, 12, 13) including a neck or sprue gate 23 (4, 12).

The mold structure is supported in general on a hollow frame assembly generally indicated at 25(1, 5, 9, 12) in a manner to be described below. The hollow frame assembly may include an outer frame 26( 1, 5, 9, 12)

and a frame ring 27(1, 5, 9-12). The hollow frame assembly is supported for movement between pouring and freezing positions by trunnion uprights 36(1, 12) having bearings which receive trunnion pins 31, which in turn are received in sleeves extending from the outer frame 26. A-sprocket 32 is fixed to one of such sleeves extending from the outer frame 26. Through a chain and sprocket linkage, the sprocket 32 is driven by a suitably actuated control shaft 33(1). p The core section 16 of the mold 10 comprises a plurality of core subsections, including a central core subsection 35 and additional core subsections 3639(8, 12). Each of the core subsections 3639 is provided with a camming tail or extension 40( 1, 9-12). The central core subsection 35 is provided with a cam skirt 41(912) and is associated with a retracting rod 42( 1, 9-12) extending from an hydraulic actuating cylinder 43(1, 12) which is supported on the frame 26. A pit or slot 44 is provided in the deck or foundation on which the apparatus is located. 7

The sprue-defining means 17 is divided into two halves 50and 51(4, 7) which are held together by releasable latches 52(1, 3, 6, 7, 12, 13). The latches are provided with handles, as shown. Formed on the sprue-defining means is female bayonet-fastening structure 53(1, 3, 4, 6, 7, 12) which is divided along the same central plane which divides the halves 50 and 51. The female bayonetfastening structure 53 is adapted to engage with corresponding male bayonet-fastening structure formed on .the hinges by the hinge arms 61(1, 2, 5).

the outside of the mold cap section 11. The sprue gate 23 passes through the center of this bayonet-fastening structure. The two halves 50 and 51 of the sprue-defining means 17 are connected for hinging movement with respect to each other by hinges 56(2-4, 6, 7, 12). A nipple 57(4, 12) is formed at the center of the female bayonet-fastening structure 53 and is adapted to seat in a socket plug 58 which is formed at the center of the corresponding male bayonet-fastening structure on the mold cap section 11. The socket plug may be threadedly received in the cap section 11, as shown, so that it may be removed from the cap section and replaced when it becomes worn. The connection through the nipple and socket plug is designed to be twisted and released, the frozen metal within the sprue gate 23 being sheared in the process of twisting the nipple with respect to the socket plug.

The side mold sections 12--15 swing outwardly on hinges 69(1, 5) which hinges are mounted on the outer frame 26. The side sectionslZ-IS are supported on Outward movement of the side sections may be limited by the stops 65(1, 5) formed on certainof the hinge arms 61. The adjoining edges of the mold side sections 13 and 14 and also the adjoining edges of the mold side sections 12 and 15 are provided with adjacent ribs 62(1, 12, 14). The mold side sections 12-15 are held in closed position by clamps 63(1, 12, 14) which'grip the rim of the mold cap section 11 and which are provided with fingers 64(12, 14) which grip a pair of side sections 13 and 14 on either side of the ribs 62. i The core subsections 36-39 swing inwardly on hinges 66(9-12). These hinges extend from the frame rim 27 on arms 68.

A female bayonet-fastening structure 70(1) may be supported over the mold 10 by a suitable overhead frame v71. The female bayQnet fastening structure 70 can be raised and lowered by an hydraulic cylinder 72, which actuates the shaft 73 from which the structure 70 is supported. The structure 70 is adapted to cooperate with the male bayonet-fastening structure on the mold cap section 11 for the purpose of lifting this cap section off when opening the mold. It will also be understood that the additional members which must be released to open the mold may be manipulated by appropriate manually held tools or by other means. Thus, for example, the clamps 63 may be loosened from the hot mold structure after a casting has been made by any appropriate tool which can grip the heads or handles of the bolts associated with the clamps 63 and back them 011. Thespruedefining means 17 can be twisted to release or engage the bayonet structure 53 by lateral pressure on the'ou'ter ends thereof when the apparatus is in the position shown in Figure 1. The shaft 73 can be twisted with a suitable wrench when the bayonet structure 70 is in lowered position in order to release or engage it with the mold cap section 11. The sprue-defining means can be hoisted into and out of position by a suitable crane-supported tong means or hook means (not shown).

The mold is suitably vented, as by providing vent grooves (not shown) in the mating cylindrical faces between vthe frame ring 27 and the core subsections 37-39. Other vents may be provided. Shown in the drawings is a vent ring 75(12) which may be grooved or which may loosely fit in the slot in which it is received, such slot being in turn vented to atmosphere by means of grooves or drilled vent passages (not shown).

In operation, the apparatus, which has been, as desired, heated and primed according to procedures familiar to the art, is positioned as shown in Figure 12. The sprue-defining means 17 have been attached by the bayonet-fastening structure to the cap mold section, and the latches 52 have been closed. The shaft 42 has been fully extended. The mold side sections have been positioned spasms inwardly in closed position 'andelamped there by the tightened clamps 63. I t Qpera'tors pour. metal from ladles into the outer ends of the sprue passage 22. The pouring is preferably continued until the level of 'themolteu metal rises to the top of the pouring passages. The molten metal flows downwardly and then upwardly through the gate or neck passage 23 into the relatively gross feeding cavity 21 and then upwardly into the casting .cavity 20. ,Air which is displacedby the incoming metal is forced out of the casting cavity through the venting grooves and passages.

When suflicient metal has been poured into the mold,

the shaft 33 is actuated to invert the apparatus from the position shown in Figure 12 to the posit-ion shownin Figure 1. In this latter position the outer end of the sprite passage 22 face downwardly. As the. mold apparatus swings over, the operators may swing their ladies to a position to catch the molten metal which flows by gravity out of the ends of the sprue passage, 22. The molten metal in the feeding cavityz l is trapped, however, and as the casting freezes, metal from this relatively gross cavity continues to How downwardly to the casting cavity to compensate for freezing shrinkage.

After a sufiicient time has been allowed for freezing of the casting, the outer endsof the sprue-defining means 17 are pushed laterally to twist off the bayonet connec tion between the sprue-defining means and the cap mold section and to shear such metal as may remain in the sprue neck or gate 23.. The sprite-defining means is then lifted away by a suitable hook or by tongs. The latches 52 may then be released'and the entire sprue= defining means may be opened and thoroughly cleaned to remove all flash and the like. The sprue-defining means is then re-closed and is ready to be, lifted into position on the molding apparatus for use in a succeeding casting operation.

Meanwhile, the bayonet structure, 70 is lowered and twisted by a wrench or the like to effect an engagement with the cap section 11. The clamps 63 are released and the cap section is raised by the hydraulic cylinder 72. 'Iheside sections 12--15 are allowed to swing outwardly to the limiting positions defined by the stops 65. The core section is retracted, the central core subsection 35 being retracted by the hydraulic cylinder 43 and the camming skirt 41 coacting with the cam tails .40 to first cause the subsections 37 and 39 to swing inwardly and then cause the subsections 36 and 38 to swing inwardly, re-

in annular shapes, such as wheel castings and the like, comprising separable mold sections which are recessed to leasing the interior of the casting and clearing the boss 7 84, as indicated in Figure 10.

The cast article is removed from the mold and the excess metal which has frozen in the feeding cavity 21 and which may contain extensive sinks and voids is machined oif in a simple turning operation.-

The various mold sections and subsections and all venting grooves and passages and the like maybe thoroughly cleaned and primed prior to reclosing the mold and preheating and returning the assembled apparatus to the position shown in Figure 12 preparatory to the succeeding pouring operation. 7

It will be seen that one feature of the invention is the provision of a ring or frame (elements 26, 27) from which one annularly extending array of mold sections swing laterally or radially outwardly (elements 1215) and another annularly extending array swings laterally or radially inwardly (elements 36-39); It is to be understood, however, that in certain broader aspects the invention is not necessarily embodied in mold apparatus having a collapsing core. For example, if it were desired to form a, wheel having no boss corresponding to the boss 84 and having an inner annular face which flared outwardly along its axial extent to a sufficient degree to allow ready mold release without collapse of the core, then a solid core could be employed which might be similar to the core shown in the drawing with the subsections 35-39 all formed. as an integral s core which would be 'shiftable.:axially out of and sea; into mating, sliding engagement within the ring '27; In such a structure, the hinges 66 would, of course, be eliminated. p

In still broader aspects of the invention, it should be understood that the invention is not necessarily embodied in molding apparatus in which both the cap and core sections include elements which shift axially with respect to the frame. For example, the core may be fixed to the frame, only the cap section being axially shiftable, or the cap may be fixed, only the co're'section being axially shiftable. The recitation in the claims that cap and core sections are axially removable relatively away from each other is not to be taken to exclude any, of the arrangements described above since relative axial removal may occur, within the meaning of this quoted language, whether-(1 neither or (2) either of the sections in question is affixed to the mold frame, so long as at least one may be shifted axially away from the other.

In general, itis to be understood that the particular apparatus and procedures described are presented for pufposes of illustration and explanation and that modifications and substitutions are contemplated and may be made without departing from the invention.

What is claimed is:

l. A permanent mold for making light-metal castings in annular shapes, such as wheel castings and the like, comprising separable mold sections which are recessed to provide an annular casting cavity and a feeding cavity, said feeding cavity being in the form of a relatively gross void in direct communication with said casting cavity, said mold sect-ions comprising a plurality of side sections, a cap section and a core section, said feeding cavity being within said cap section, said cap section having sprue-defining means associated therewith and extending therefrom, means for supporting said mold'to turn from a pouring position in which the feeding cavity is lower than the casting cavity to a reverse freezing position in which molten metal in said feeding cavity continues to feed into the casting cavity prior to completion of freezing, said cap and core sections being axially removable relatively away from each other, said side sections being laterally removable from closed positions and from both, said cap and core sections.

2. Apermanent mold for making light-metal castings provide an annular casting cavity and a feeding cavity, said feeding cavity being in the form of a relatively gross void in direct communication with said casting cavity, said mold sections comprising a plurality of side sections, a cap section and a core section, said feeding cavity being within said cap section, said cap section having spruedefining means associated therewith and extending therefrom, means for supporting said mold to ,turn from a pouring position in which the feeding cavity is lower than the casting cavity and said sprue-defi'ni'ng means extends downwardly from above said casting cavity and feeds upwardly into the feeding cavit'y tov a reverse freezing position in which molten metal in said feeding cavity continues to feed into the casting cavit'y prior to completion of freezing, said cap and core sections being axially removable relatively away from each other, said side sections being laterally removable from closed positions and from both said cap and core sections.

3. A permanent mold for making light-metal castings in annular shapes having axially and laterally re-e'ntr'ant portions, such as wheel castings and the like, comprising separable mold sections which are recessed to provide an annular casting cavity and a feeding cavity, said feeding cavity being in the form of a relatively gross void in direct communication with said casting cavity, said mold sectons comprising a pluralityof side sections; acap section and a c'o're Section, said feeding cavity being. within said cap section, said cap section having sprites "defining means associated therewith and extending therefromfmeans for supporting said mold to turn from'a pouring position 'in which the feeding cavity is lower than the casting cavity and said sprue-defining means extends downwardly from above said casting cavity and feeds upwardly into the feeding cavity to a reverse freezing position in which molten metal in said feeding cavity continues to feed into the casting cavity prior to completion of freezing, said cap and core sections being axially removable relatively away from each other, said side sections being laterally removable from closed positions and from both said cap and core sections, said core section comprising inwardly collapsible means for clearing laterally re-entrant inward radial projections on castings formed in the mold; I

4. A permanent mold for making light-metal castings in axially re-entrant annular shapes, such as wheel castings and the like, comprising' separable mold sections which are recessed 'to provide an axially re-entrant annular casting cavity and a feeding cavity, said feeding cavity being in the form of a relatively gross void in direct communication with said casting cavity, said mold sections comprising a plurality of side sections, acap section and a core section, said feeding cavity being within said cap section, said cap section having sprue-defining means associated therewith and extending therefrom, means for supporting said mold to turn from a pouring position in which the feeding cavity is lower thanthe casting cavity and said spruedefining means extends downwardly from above said casting cavity and feeds upwardly into the feeding cavity to a reverse freezing position in which molten metal in said feeding cavity continuous to feed into the casting cavity prior to completion of freezing, said cap and core sections being axially removablerelatively away from each other, said side sections being laterally removable from closed positions and from both said cap and core sections, said sprue-defining means being removable from said cap section prior to opening of said mold.

5. A permanent mold for making light-metal castings in annular shapes having axially and laterally re-entrant portions, such as wheel castings and the like, comprising separable mold sections which are recessed to provide an annular casting cavity and a feeding cavity, said feeding cavity being in the form of a relatively gross void in direct communication with said casting cavity, said mold sectons comprising a plurality of side sections, a cap section and a core section, said feeding cavity being within said cap section, said cap section having spruedefining means associated therewith and extending there from, means'for supporting said mold to turn from a pouring position in which the feeding cavity is lower than the casting cavity and said sprue-defining means extends downwardly from above said casting cavity and feeds upwardly into the feeding cavity to a reverse freezing position in which molten metal in said feeding cavity continues to feed into the casting cavity prior to completion of freezing, said cap and core sections being axially removable relatively away from each other, said side sections being laterally removable from closed positions, said core section comprising inwardly collapsible means for clearing laterally re-entrant inward radial projections on castings formed in the mold, said sprue-defining means being joined to said cap section by a bayonet connection and communicating therewith through a neck at the center of said bayonet connection whereby when said bayonet connection is twisted for release, frozen metal within said neck is subjected to high shearing moments and is parted.

6. A permanent mold for making light-metal castings in annular shapes having axially and laterally re-entrant portions, such as wheel castings and the like, comprising separable mold Sections which are recessed to provide an annular casting cavity and a feeding cavity, said feeding cavity being inthe forn rof a relatively gross void in direct communication with said casting cavity, said mold sections comprising a plurality of'side sections, a capsection and a core section, said feeding cavity being within said cap section, said cap section having spruedefining means associated therewith and extending therefrom, means for supporting said mold to turn from a pouring position in which the feeding cavity is lower than the casting cavity and said sprue-defining means extends downwardly from above said casting cavity and feeds upwardly into the feeding cavity to a reverse freezing position in which molten metal in said feeding cavity continues to feed into the casting cavity'prior to completion of freezing, said cap and core sections being axially removable relatively away from each other, said side Sections being laterally removable from closed positions, said core section comprising inwardly collapsible means for clearing laterally re-entrant inward radial pro jections on castings formed in the mold, said sprue-defining means being joined to said cap section by a bayonet connection and communicating therewith through a neck at the center of said bayonet connection whereby when said bayonet connection is twisted for release, frozen metal within said neck is subjected to high shearing moments and is parted, said sprue-defining means being divided into a plurality of parts along a plane extending through the sprue ways defined by said means, and means to releasably hold said parts in closed position.

7. A permanent mold for making light-metal castings in annular shapes having axially and laterally re-entrant portions, such as wheel castings and the like, com prising separable mold sections which are recessed to provide an annular casting cavity and a feeding cavity, said feeding cavity being in the form of a relatively gross void in direct communication with said casting cavity, said mold sections comprising a plurality of side sections, a cap section and a core section, said feeding cavity being within said cap section, said cap section having sprue-defining means associated therewith and extending therefrom, means for supporting said mold to turn from a pouring position in which the feeding cavity is lower than the casting cavity and said sprue-defining means extends downwardly from above said casting cavity and feeds upwardly into the feeding cavity to a reverse freezing position in which molten metal in said feeding cavity continues to feed into the casting cavity prior to completion of freezing, said cap and core sections being axially removable relatively away from each other, said side sections being laterally removable from closed positions, said core section comprising inwardly collapsible means for clearing laterally re-entrant inward radial projections on castings formed in the mold, said sprue-defining means being joined to said cap section by a bayonet connection and communicating therewith through a neck at the center of said bayonet connection whereby when said bayonet connection is twisted for release, frozen metal within said neck is subjected to high shearing moments and is parted, said sprue-defining means being divided into a plurality of parts along a plane extending through the sprue ways defined by said means, and means to releasably hold said parts in closed position, the sprue ways defined by said sprue-defining means comprising two sprue ways which, in pouring position, extend downwardly from above opposite sides of said casting cavity and then join into a common sprue way extending up through said neck to said feeding cavity. V V

8. A permanent mold for making light-metal castings in annular shapes having axially and laterally re-entrant portions such as wheel castings and the like, comprising separable mold sections which are recessed to provide an annular casting cavity and a feeding cavity, said feeding cavity being in the form of a relatively gross void in direct communication with said casting cavity, said mold sections comprising a plurality of side sections, a cap section and a core section, "said feeding cavity being within said cap section, saidcap section having sprue-defining means associated therewith and extend.- ing therefrom, means for supporting said mold to turn from a pouring position in which the feeding cavity is lower than the casting cavity and said sprue-defining means extends downwardly from above said casting cavity and feeds upwardly into the feeding cavity to a reverse freezing position in which molten metal in said feeding cavity continues to feed into the casting cavity prior tocompletion of freezing, said cap and core sections being axially removable relatively away from each other, said side sections being laterally removable from closed positions and from both said cap and core sections, said core section comprising inwardly collapsible means for clearing laterally re-entrant inward radial projections on castings formed in the mold.

9. A permanent mold for making light-metal castings in annular shapes having axially and laterally re-entrant portions, such as wheel castings and the like, comprising separable mold sections which are recessed to provide an annular casting cavity and a feeding cavity, said feeding cavity being in the form of a relatively gross void in direct communication with said casting cavity, said mold sections comprising a plurality of side sections, a cap section and a core section, said feeding cavity being within said cap section, said cap section having spruedefining means associated therewith and extending therefrom, means for supporting said mold to turn from a pouring position in which the feeding cavity is lower than the casting cavity and said sprue-defining means extends downwardly from above said casting cavity and feeds upwardly into the feeding cavity to a reverse freezing position in which molten metal in said feeding cavity continues to feed into the casting cavity prior to completion of freezing, said cap and core sections being axially removable relatively away from each other, said side sections being laterally removable from closed positions, said core section comprising inwardly collapsible means for clearing laterally re-entrant inward radial projections on castings formed in the mold, said sprue-defining means being joined to said cap section by a bayonet connection and communicating therewith through a neck at the center of said bayonet connection whereby when said bayonet connection is twisted for release, frozen metal within said neck is subjected to high shearing moments and is parted.

10. A permanent mold for making light-metal castings in annular shapes having axially and laterally re-entrant portions, such as wheel castings and the like, comprising separable mold sections which are recessed to provide an annular casting cavity and a feeding cavity, said feeding cavity being in the form of a relatively gross void in direct communication with said casting cavity, said mold sections comprising a plurality of side sections, a cap section and a core section, said feeding cavity being within said cap section, said cap section having spruedefining means associated therewith and extending therefrom, means for supporting said mold to turn from a pouring position in which the feeding cavity, is lower than the casting cavity and said sprue-defining means extends downwardly from above said casting cavity and feeds upwardly into the feeding cavity to a reverse freezing position in which molten metal in said feeding cavity continues to feed into the casting cavity prior to completion of freezing, said cap and core sections being axially removable relatively away from each other, said side sections being laterally removable from closed positions, said core section comprising inwardly collapsible means for clearing laterally re-entrant inward radial projections on castings formed in the mold, said spruedefining means being joined to said cap section by a bayonet connection and communicating therewith through a neck at the center of said bayonet connection whereby when said bayonet connection is twisted for release,

frozen metal within said neck is subjected-to high shear: ing moments'and is parted, said sprue-defining means being divided into a plurality of parts along a plane extending through the sprue ways defined by said means, and means to releasably hold said parts in closed position. i

a 11. A permanent mold for making light-metal castings in annular shapes having axially and laterally re-entrant portions, such as wheel castings and the like, comprising separable mold sections which are recessed to provide. an annular casting cavity and a feeding cavity, said feeding cavity being in the 'form of a relatively gross void in direct communication with said casting cavity, said mold sections comprising a plurality of side sections, a cap section and a core section, said feeding cavity being with in said cap section, said'cap section having a sprue.- defining means associated therewith and extending therefrom, means for supporting said mold to turn from a pouring position in'which the feeding cavity is lower than th sa t ns it a d ru efinin me ns extends downwardly from above said casting cavity and feeds upwardly into the feeding cavity to a reverse freezing position in which molten metal in said feeding cavity continues to feed into the casting cavity prior to completion of freezing, said cap and core sections being axially removable relatively away from each other, said side sections being laterally removable from closed positions, said core section comprising inwardly collapsible means for clearing laterally re-entrant inward radial projections on castings formed in the mold, said sprue-defining means being joined to said cap section by a bayonet connection and communicating therewith through a neck at the center of said bayonet connection whereby when said bayonet connection is twisted for release, frozen metal within said neck is subjected to high shearing moments and is parted, said sprue-defining means being dividedinto a plurality of parts along a plane extending through the sprue ways defined by said means, and means to releasably hold said parts in closed position, the sprue ways defined by said sprue-defining means comprising two sprue ways which, in pouring position, extend downwardly from above opposite sides of said casting cavity and then join into a common sprue way extending up through said neck to said feeding cavity.

12. A permanent mold for making light-metal castings in axially re-entrant annular shapes, such as wheel castings and the like, comprising frame means supported for movement between inverted pouring position and upright freezing position, mold sections in supported association with said frame means and closable with each other for defining in closed position an axially re-entrant annular casting cavity and a feeding cavity in the form of a relatively gross void in direct communication with said casting cavity, said mold sections comprising a plurality of side sections, a cap section and a core section, said cap section being the lowermost section when the structure is in inverted position, said feeding cavity being within said cap section, sprue-defining means associated with said cap section and extending therefrom to' above said casting and feeding cavities when the structure is in inverted position, said cap and core sections being axially removable relatively away from each other, said side sections being laterally removable from closed position and from both said cap and core section.

13. A permanent mold for making light-metal castings comprising hollow frame means supported for movement between inverted pouring position and upright freezing position, mold sections in supported association with said frame means and closable with each other for defining in closed position a casting cavity, said mold-sections comprising a plurality of side sections, a cap section extending into one end of said side sections in closed position and a core section, said side sections being mounted for swinging independently of said cap and core sections laterally outwardly from said frame means and from closed position, said core section comprising collapsing subsections mounted for swinging laterally inwardly from said frame means and from closed position.

14. A permanent mold for making light-metal castings comprising frame means supported for movement between inverted and upright positions, mold sections in supported association with said frame means and closable with each other for defining in closed position an annular casting cavity, said mold sections comprising a plurality of side sections each mounted for swinging independently of the other mold sections laterally outwardly from said frame means and from closed position, a cap section extending into one end of said side sections in closed position and a core section extending into the opposite end of said side sections when in closed position, said cap and core sections being axially removable relatively away from each other.

15. A permanent mold for making light-metal castings comprising frame means supported for movement between inverted and upright positions, mold sections in supported association with said frame means and closable with each other for defining in closed position an annular casting cavity, said mold sections comprising a plurality of side sections each mounted for swinging independently of the other mold sections laterally outwardly from said frame means and from closed position, a cap section fitting within one end of said side sections in closed position and removable therefrom in an axial direction, and a core section extending into the opposite end of said side sections.

References Cited in the file of this patent UNITED STATES PATENTS 1,030,198 McKee et al June 18, 1912 1,719,795 Bacon July 2, 1929 1,770,368 Fahlman July 8, 1930 2,029,499 Norton et al Feb. 4, 1936 2,061,765 Guyot Nov. 24, 1936 2,266,723 Fahlman Dec. 16, 1941 2,553,744 Brammer May 22, 1951 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent Noe 2.932 070 April 12 1960 Sidney Wo Jackson et a1.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should readas corrected below.

Column 1O line l6 after "having" strike out "a"; line 64 for "section" read sections Signed and sealed this 27th day of September 1969.,

(SEAL) Attest:

KARL Ho AXLINE ROBERT C. WATSON Attesting Officer Commissioner of Patents

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