US 3136008 A
Description (OCR text may contain errors)
C. E. MAIER ETAL June 9. 1964 APPARATUS AND METHOD FOR CONTINUOUS CARTING OF INGOTS HAVING LONGITUDINAL. CHANNELS AND SPACER MEMBER THEREIN Filed June 20, 1960 5 Sheets-Sheet 1 a F W 2 E @E LJILA INVENTORS Cum-n s E..MA\EQ giflZoeEzr MBzmn BY 7mm, 9, 0%
ATTO IZN EY5 June 9, 1964 c MAIER ETAL 3,136,008
APPARATUS AND METHOD FOR CONTINUOUS CARTING OF INGOTS HAVING LONGITUDINAL CHANNELS AND SPACER MEMBER THEREIN Filed June 20, 1960 5 Sheets-Sheet 2 8 I 255i kzfiqo '30 $5 32 i w I i: a; a \g TIE-.5 s h ATTOQHEYS June '9. 1964 c. E. MAIER ETAL 3,135,003
APPARATUS AND METHOD FOR CONTINUOUS CARTING OF INGOTS HAVING LONGITUDINAL CHANNELS AND SPACER MEMBER THEREIN Filed June 20, 1960 5 Sheets-Sheet 3 4 TIE-.EA 744 34 aeoomae e INVENTORJ' Cum-us E. Mmazy 20522.1 MBmcvc AT TQQMEY$ June 9, 196 c. E. MAIER ETAL APPARATUS AND METHOD FOR CONTINUOUS CART'ING OF INGOTS HAVING LONGITUD-INAL CHANNELS AND SPACER MEMBER THEREIN Filed June 20, 1960 5 Sheets-Sheet 4 TIE--15 m 5 /J r 5 o O m q /q o 4 o s q 0 INVENTORS Cwzrn s EMMEZ EJ205221 VLBmcK QM M 5m,
ATToQUt-IYS June 9', 1964 c. E. MAIER ETAL 3,136,008 APPARATUS AND METHOD FOR CONTINUOUS CARTING 20F INGOTS HAVING LONGITUDINAL CHANNELS AND SPACER MEMBER THEREIN 5 Sheets-Sheet 5 Filed June 20, 1960 an. an: m: ma.
INVENTORJ C u 2115 E. Mmaz & Eosem' H. BraucK BY w, rva @AJA aw d ATTORNEYS United States Patent 3,136,008 APPARATUS AND METHOD FOR C(DNTINUOUS (IASTING 0F INGOTS HAVING LQNGITUDINAL CI IANNELS AND SPAQER MEMBER THEREEN Curtis E. Maier, Riverside, and Robert M. Brick, H1115- dale, 111., assignors to Continental Can Company, Inc., New York, N.Y., a corporation of New York Filed June 20, 1960, Ser. No. 37,267 8 Claims. (Cl. 22-572) This invention relates to the production of hollow bodies such as tubes by rolling an internally channelled billet into laminate strip, and then separating laminations of the strip to form the body.
An object of the invention is the production of an ingot having channels provided by cores fixed relative to the ingot mold, with the feeding of spacer pieces between the cores for bonding to the ingot metal.
Another object is the provision of apparatus for the production of ingots having internal channels separated from one another by metal spacers separately fed to the ingot mold.
A further object is the production of an ingot having multiple internal channels by employment of cooled cores fixed relative to the ingot mold, and having shapes for facilitating the movement of the cooling ingot metal relative to the cores.
A further object is the production of a billet with open internal channels and internal discontinuities between such channels which can be rolled into a multi-wide strip stock, for trimming and severance into single-wide strips by overstressing at the regions of the residues of the discontinuities between the internal channels.
With these and other objects in view, as will appear in the course of the following description and claims, illustrative embodiment of the invention is shown in the accompanying drawings, in which:
FIGURE 1 is an upright section through a conventionalized casting apparatus, with parts adapting it for the present invention;
FIGUREZ is a section substantially on line 2-2 of FIGURE 1, showing the path of spacer pieces and ingot;
FIGURE 3 is a horizontal section of the mold with spacers and fixed cores therein, substantially on line 33 of FIGURE 1;
FIGURE 3A is a section corresponding to FIGURE 3, and showing the incorporation of pro-formed edge pieces;
FIGURE 4 is a fragmentary horizontal section, sub-' stantially on line 44 of FIGURE 1, on an enlarged scale;
FIGURE 4A is a section corresponding to FIGURE 4, and showing the feeding of edge pieces as in FIG- URE 3A;
FIGURE 5 is an upright section substantially on line 55 of FIGURE 4;
FIGURE 6 is an enlarged view of a part of FIGURE 2, with parts broken away to show cooling passages in a fixed core;
FIGURE 6A is a view corresponding to FIGURE 2, with the ingot in elevation, and showing the use and bonding of edge pieces as in FIGURES 3A and 4A;
FIGURE 7 is a view corresponding to FIGURE 5, and showing a modified structure;
FIGURE 8 is a perspective view showing the employment of brakes for a pair of spacer guiding rollers;
FIGURE 9 is a perspective View of the lower end of a fixed core;
FIGURE 10 is a perspective view of one form of spacer piece;
FIGURES 10A, 10B and 10C show the engagement of core and spacer pieces during the preparation of ingots;
3,136,008 Patented June 9, 1964 FIGURE 11 is a perspective view of the upper end of an ingot prepared with spacer pieces as in FIG- URE 10;
FIGURE 12 is a perspective view of another form of spacer piece;
FIGURE 13 is a view corresponding to the upper part of FIGURE 2, showing an arrangement for feeding spacer pieces as in FIGURE 12;
FIGURE 14 is a perspective view of the upper end of an ingot prepared with spacer pieces as in FIGURE 12.
The invention has been illustrated by the preparation of ingots with four channels, for making a four=wide rolled laminate strip; but is employable for a desired even or odd number of such channels. Relative dimensions of width and thickness have been exaggerated for clearness.
In FIGURES 1 and 2 is conventionally shown a casting apparatus appropriate for the practice of this invention. A mold 20, open at top and bottom, has a cooling chamber 21 to which water can be delivered by aconduit 22 and removed by a conduit 23. At the beginning of a casting operation, the bottom of the mold 20 is closed by a platform 24 which can be raised to closing position by a hydraulic ram. This ram has a cylinder 25 and a piston 26: conduits from the upper and lower ends of the cylinder lead to a valve 27 which can be operated to pass fluid under pressure from a supply pipe 28 to the lower end of the cylinder for raising the platform, or to the upper end of the cylinder to permit or facilitate the downward movement, with respective discharge from the other cylinder end by pipe 29. I
Brackets 30 are connected with the mold 20 with inclusion of cushions 31 which permit limited relative movements. These brackets carry a core support 32 above the upper end of the mold: and frame pieces 33 which support guide rollers 34 for spacer inserts as set out hereinafter. A vibrator 35 is connected to the core support 32 to give the same limited vibrations horizontally in the greater or width direction of the ingot, of around 0.001 inch. Such vibration creates shear motions at the partly solidified interfaces of the wider parts of the cores and impingement at the spacer interfaces, to minimize sticking to the fixed cores and to assist in the metal bonding or welding of the molten metal to the spacer pieces.
The core support 32 and guide rollers 34 receive the spacer inserts 41, FIGURE 1, and assure regular positioning and downward movement thereof into and through the mold during a casting operation. A tundish 36 has bifurcated branches at the sides of the spacers and the cores 40 which are aligned with the spacers, and drop tubes by which the molten metal can flow regularly downward into the mold without splashing or the formation of air bubbles. Flames from burners 38, FIGURE 1, may be employed to raise the temperature of the inserted spacers 41 to assure the weld-bonding.
The apparatus permits the casting of ingots having a desired number of longitudinal channels therein, four being illustratively shown. In FIGURE 3, these channels are to be formed by the four fixed cores 40a, 40b, 40c, 40d. Between and at the ends of these cores are provided spacer insert pieces 41a, 41b, 41c, 41d, 412 which can have longitudinal grooves for receiving and being in guided relationship to the fixed cores. The spacer pieces 41a, etc., extend beyond the cores, and are shown as aligned with inwardly projecting ribs 42 on the mold walls.
The edges of the cores 49 are inter-fitted with the spacers; with the core edgeshaving convergent edges, e.g., of rounded form but preferably of a chisel-shape formed by convergent plane surfaces extending from'a radius of, say, & inch at the extreme edge and merging with the parallel major surfaces. The angle between the and molten ingot metals.
convergent plane surfaces can be between and 90 degrees: in practice, little difference has been observed the major wall surfaces 40s of the core extend from the surfaces 66s of the spacers. In FIGURE 10B, the edge angle of the cores 40 is about 30 degrees, the spacers 66 have a thickness of 0.125 inch with a groove angle of 30 degrees and depth of 0.062 inch: wherewith the parts interfit and interlock but the material of the spacer does not extend to the mergings of the convergent plane surfaces with the parallel wall surfaces 40s of the cores, and the ingot channels have forms as in FIGURE 14. Curved concave grooves in the spacers 66, and conforming convex edges on the cores 40 may be employed, as shown in FIGURE 10C. In each case, the cores leave a channel or discontinuity and the spacers and poured metal provide integrated metal in the ingot which connects the ingot structure at the edges of each channel and between the adjacent channels: and this integrated metal has such a section that during rolling there is not present a slender column of metal which may be distorted and bent laterally; with such shaped at the cores and corresponding shapes of the longitudinal grooves in the spacers, the metal intervening between adjacent channels is then at the center of spacers and presents broad bases at the upper and lower surfaces of the channels during rolling, and therewith the intercore metal can be kept thin so that little trimming is needed upon the fins of the expanded tube produced therefrom.
The dihedral angle between the surfaces at the edges of the cores 40 may be from 10 to 60 degrees, and may be as great as 90 degrees for some selections of spacer In practice with aluminum and aluminum alloys, angles of 14 and 28 degrees have been found satisfactory to prevent any orange peel effect being formed when a liquid anti-welding resist is present during the early or break-down stages of hotrolling, such as may occur when the core edges are at right angles to the wider surfaces; and have resulted in excellent control of the lamination widths.
One form of core support 32 is shown in FIGURES 4 and 5, where two blocks 44, 45 can be clamped together by bolts 46 with the upper ends of the cores 40a, 40b, 40c, 40d held therebetween. Each block has a water header 47 or 48, to which water is delivered by a flexible metal supply pipe 49 or removed by a flexible metal pipe 50. The cores 40a, 40b, 40c, 40d are made, FIGURES 3-5 and 9, with two longitudinal passages 51, 52 therein. At the upper ends of each core, FIGURES 4 and 5, there are branch passages which communicate respective ly with the headers 47, 48. Between the core positions, the blocks 44, 45 have cavities 53 for receiving and guiding the spacer pieces 41a, 41b, 41c, 41d, 412.
In the modified form of core support, FIGURE 7, the individual core 40a, for example, has the two longitudinal passages, but these communicate at the top for servicing with water by the inlet and outlet flexible metal pipes 49a, 50a which can be individually connected to water supply and discharge headers for the several cores.
The procedure is adaptable to the employment of ingot metal which is subject to edge-cracking during rolling. In such cases, it is preferrred to provide edges on the billet which are of more ductile metal. Thus, in FIG- URE 3A, the parts of the composite ingot which are to form the lateral edges during rolling are constituted by pre-forrned edge pieces 41x which may be of pure aluminum when the cast metal is of an aluminum alloy which is harder and less ductile during the rolling; or may be forged metal of the same analysis, e.g., forged 2024 alloy with the 2024 alloy being poured, noting that cracking at and from the edges largely develops during the initial working from the cast structure to the worked structure. Therewith the burners 38a, FIGURE 6A, may be employed to heat the edge pieces 41x to a temperature close to the melting point, to assure the weld-bonding upon contact by the molten metal; and therewith the edge pieces 41x have little resistance to bending so that they enter the mold and conform to the ingot metal being poured and solidifying. Also, rollers 34a may be employed to engage the ingot below the mold, and preserve integrity of the structure and prevent rupture of the weld bond during the solidification by the action of shrinkage forces and any resistance to bending of the edge pieces. During the casting, these edge pieces 41x as well as the spacers 41 become integrated into the ingot, by the bonding of the molten metal to the exposed surfaces of these parts: therewith, the material for the edge pieces is of metal which can intermix with the casting metal so that the bond extends over the entire interfaces, with preference for having the base metal of the edge pieces the same as the base for the cast metal, e.g., aluminum or a soft aluminum alloy when the cast metal is a hard aluminum alloy, copper when the cast metal is a tin or silicon bronze. Thus, the edge pieces 41x can be of the same analysis and prepared in the same way as the spacers 41 for a given cast metal. During the subsequent rolling, these edge pieces 41x are reduced with the cast structure, and therewith serve to maintain the cast metal under tri' axial compression during passage between the rolls, rather than uniaxial compression at the edges as occurs when the edges of the cast metal are exposed and free during rolling.
For this, as shown in FIGURE 4A, the core support has the blocks 44, 45 shaped for the passage of the edge pieces as well as the spacers 40, and supports the cores 41 with delivery of cooling medium thereto and removal therefrom by conduits 49, 50.
The several cores 40, FIGURE 9, are tapered so that the outer surfaces converge downwardly in both the thickness and the width of the core. This tapering is shown as extending from the lower ends of the cores to points above the mold, to permit changes of molten liquid level during the pouring: and the angle of convergence is selected in accordance with the shrinkage of the ingot metal during cooling from molten to solid condition, and during its further contact with the core: for aluminum and aluminum alloys, the angle can be between 8 degrees and one degree dependent upon the ingot composition and its thermal contraction factor, the thermal contraction of the core material, and the distance of contact. These cores can be prepared for facile freeing from the ingot as the latter moves downward: and can be easily replaced or interchanged in the support 32. The passages 51, 52
can be formed by drilling, or by casting core body material upon pipes for providing the passages. The passages, FIGURES 6 and 9, are cross-connected near their lower ends so that water can flow downward in one passage and then upward in the other. In FIGURE 6, the lower ends of the passages and the cross-connection are illustratively shown as closed by a sealing plug 54.
When ingots of other than aluminum and aluminum alloys are to be made, the material for the cores is selected for its non-welding with the molten metal. With steel, the cores can have graphite surfaces, for example, by forming them as porous graphite bodies having a passage therein closed at the bottom, and with an oil under pressure being forced into the passages so that it oozes from the surface and provides a lubricant for the downward movement of the solidifying steel and also provides protection against oxidation of the cores. This employment of oil is also useful with aluminum and other metals: the mold wall can be coated with oily grease before the pouring is started, and the supply replenished from time to time by applying the grease to the parts of the mold wall above the liquid level; and acts to prevent sticking.
The cores 40 preferably not only taper in thickness and width; but also, FIGURE 6, they are convergent relative to one another. FIGURE 6 shows such angular relationship in exaggerated form, for clearness; and indicates the relationships at th top 55 of the liquid level in the mold, compared to the shrunken size of the ingot at the line 56 where it approaches a temperature of, say, 800 to 1,000 degrees F.; noting that, at completion of a casting operation, the ingot may still have a temperature above 400 degrees F. at its end in contact with the plat form 24. This tapering, and the effects of vibration when employed, permit the ingot to slide downward along the cores, without compression thereon which might cause the ingot to remain suspended thereon. The spacer pieces 41a, 41b, 41c, 41d, 41a are heated as they move downward toward the mold, and increase in size, with the distance between the cores selected to accommodate them: as the spacer pieces pass through the molten metal zone, they cool with the ingot and contract again, this also being provided for by having the shapes and positions of the cores to correspond. In practice, the molten metal chills and provides a solidified structure adjacent the cooled mold walls and the cooled fixed cores, while other parts of the metal solidify later during the downward movement, as shown by the curved dash lines 57 in FIGURE 1. With most molten metals, there is a sudden shrinkage during the change from liquid to solid state, followed by further shrinkage as the temperature of the solidified metal drops. This behavior is conventionalized in FIGURE 5, where the molten liquid level 55 is at an upper part of the mold, and the wall-solidification occurs down to the line 58 at which the solidifying of the bosom of the metal causes shrinkage to become significant, with the further contraction down to the line 56 representing the thermal shrinkage of the solidified metal, the amount of contractions being exaggerated for clearness.
The cores 40a, 40b, 40c, 40d extend from the support 32 above the mold 20 down into the mold to a depth at which the solidified surface portions of the ingot are strong enough to be self-sustaining. As shown in FIGURES l and 6, the lower ends of the cores are preferably above the bottom of the mold; and further cooling of the ingot as it emerges from the mold may be accomplished by jets of cooling water from the nozzles 59.
In operation, the spacer pieces 41a, 41b, 41c, 41d, 41c are guided downward in alignment with the cores 40a, 40b, and preferably are connected to the platform 24. Thus the lower end of the spacer piece may be tapered to make a tight, liquid-sealing fit in a mating aperture in the platform, FIGURE 1, and secured as by a wedge 60.
The spacer pieces 41a, 41b, 41c, 41d, 41c are guided and controlled above the mold by the rollers 34. It is preferred to have the pieces under tension, whichis illustratively effected by the brakes 61, FIGURE 8, bearing upon the rollers 34 for the spacer 41a.
The spacer pieces 41a, 41b, 41c, 41d, 41e may be stiff bars 41, FIGURE 10, of metal which bonds to the molten ingot metal. Such strips, when solid as in FIGURE 10, may have a width of 2 inches for an ingot which is to be 8 inches thick and have channels inch or less thick; with a strip thickness of A inch, and longitudinal grooves of semicircular section inch deep and of width to receive the edges of the cores. The strips may be made by extrusion, forging or rolling, with a forged or rolled structure preferred. The strips are cut to length and straightened before use. With existing casting equipment for ingots about 14 feet long, the cut strips which are to be used as spacer pieces can be 15 feet long.
The spacer piece metal must be able to establish bonds with the molten metal brought into contact therewith. The metals may be of the same analysis, with low superheating of the molten metal above its melting point, and
'6 by the cooling effects of the adjacent'fixed cores: the product is a homogeneous metal in the rolled strip. The metals may be different: for example, an aluminum alloy of high hardenability may be used for the molten ingot metal, and the spacer pieces may be of commercially pure aluminum or of a softer aluminum alloy. When the spacer pieces are of softer material thanvthe cast metal for the laminations, these pieces permit theopening or expansion of the fixed strip and elimination of the reentraut angle to be accomplished, without cracking along the edges of the laminations. For example, when an aluminum alloy is being cast for the major part of the ingot, the spacer pieces 41 can be of pure aluminum rolled to the desired form. Therewith, the strip produced from the ingot will have the longitudinal portions which embrace the edges of the channel of metal which is more ductile than the portions which provide the laminations.
In the modified form of FIGURES 12 and 14, the spacer pieces 41 are composite. Two like strips 66, preferably of forged or rolled metal, and bondable to the molten ingot metal, each having a longitudinal groove 65 therein. Prior to employment, a weld-preventing resist is applied to one or both strips at the area where they are to be brought in contact: such resist coating being shown by stippling 67 in FIGURE 12. Such strips may be 0.125 inch thick, with grooves about 0.063 inch deep for receiving the edge of the respective contacting core. These may be formed into coils 70, FIGURE 13, and fed over turning rolls 71 into alignment with the guide roll pairs 34 and thus into the cavities 53 of the core support. The anti-weld material can be supplied by nozzles 72 which deliver a smoky acetylenetorch flame against the side of the strip which is to be prevented from welding: thereby a soot layer of 0.001 inch or less is deposited thereon.
It will be noted that the spacer piece which is employed for outer edges of the lateral channels need have a groove at only the face which contacts the respective core. Thus, in FIGURE 14, only a single strip 66 is employed at each side, with a weld-preventing coating at its outer, flat, surface 74, FIGURE 20. Correspondingly, in FIGURE 6, only the outer surfaces '74 of the spacer pieces 41a, 416 preferably have such resist material.
While the assembly of fixed cores and spacer pieces will operate with fiat faces on the spacers, it is preferred to form the spacer pieces with longitudinal grooves as shown, for preserving alignment of the parts, and to form the channels with rounded edges and with the interfaces of the spacers and molten metal spaced from the edges of the laminations provided in the rolled strip.
It is preferable to employ an agent for promoting the bonding of the liquid ingot metal to the spacer pieces. Thus, a mixture of halide salts can be employed having a melting point below that of the ingot metal, and as an eutectic mixture of chlorides having a melting point around 900 to 1,000 degrees F. With aluminum and aluminum alloys. It is feasible to employ the bonding promoter'as fine particles in a volatile vehicle, and to apply the same to the spacer pieces before these enter the mold, as by use of the rollers 34 for the purpose of delivering thin coatings to the transverse surfaces which are to be bonded.
For casting the ingot, the platform 24 is'raised by the ram 25, 26 to position for sealing the bottom of the mold 20 and engaging the fixed cores. The spacer pieces 41 are introduced between and at the ends of the cores and are secured and sealed to the platform. Molten metal is then admitted, until it forms a liquidlevel in the mold. A desirable temperature of the molten metal is about 20 to 50 degrees F. above the liquidus or melting point for aluminum and its alloys. This initial metal is permitted to cool and solidify, so that further molten metal is contained. The ram is operated so that the ingot end moves downward: and the rate of its movement and the pouring of metal by the tundish 36 is coordinated so that the liquid level remains substantially constant in the mold. As the ingot B moves downward, it leaves the fixed cores and has channels as provided by these cores. The spacer pieces 41 become embedded in the initially cooled metal, and move downward through the molten metal, becoming bonded therewith so that they are integrated parts of the ingot: being guided by the cavities 53 in the core support 32 and by the rollers 34 which are lightly braked to maintain a mild tension on the spacer pieces and hence hold them in position. The spacer pieces assure the presence of sound metal between the cores, and thus between the channels formed thereby: noting that the spacing between the cores may be 4; inch or less, so that the molten metal will not flow into such crevices and fill the same adjacent the cold cores.
When the ram and platform approach their limit of travel, the pouring of metal is slowed and stopped. The ingots B produced are shown in FIGURES 11 and 14. In FIGURE 11, solid spacer pieces, as in FIGURE 10, have been used, with parts 80 thereof projecting at the upper end of the ingot, with channels 81 therebetween of a shape and size determined by the fixed cores. When the ribs 42 are employed on the mold walls, the ingot has correspondingly-shaped longitudinal grooves 82 on its surfaces. In FIGURE 14, the projecting ends 80 of the spacers show that the form of FIGURE 12 has been employed.
The ingots can then be scalped and the internal channels provided with anti-welding material. They can then be hot and cold rolled to provide strips having internal discontinuities as residues of the channels formed by the cores, between surface laminations of metal which are integrally connected at the edges of such discontinuities; and with further internal discontinuities between the channel residues, which permit accurate severance of the strips along lines which are parallel to the edges of the channel residues and without intrusion into such channel residues.
The chisel-shape of the channels or discontinuities, as shown by the cores 40 in FIGURES A and 10B, is advantageous with resists which are in liquid form during the early or break-down passes of hot-rolling: therewith the liquid resist provides a coating for the internal surfaces and these surfaces approach one another without distortions such as crinkling being present on the channel surfaces. With the curved edges of FIGURE 10C, a solid resist can be introduced, preferably with vibration of the ingot to attain a uniform density of resist.
The illustrative practices shown are not restrictive; and the invention may be practiced in many ways within the scope of the appended claims.
What is claimed is:
1. The method of making an ingot having an internal longitudinal channel which comprises fixedly supporting a channel forming permanent core above a casting mold having a mold space with the upper and lower ends open and with the lower ends of the core located in the mold space, holding spacer members in upright position and in abutment against the edges of the core so that the spacer members and core are located essentially in a first plane extending between end surfaces of the casting mold, and with upper parts of the spacer members projecting upward out of the mold space, said spacer members being of metal capable of bonding with the molten ingot metal to form an integrated ingot and having longitudinal grooves at the surfaces for abutment with the core edges which in cross-section mate the cross-section of the core edges so the spacer members are engaged and guided by said core edges, said spacer members each having an antiwelding film on the surface thereof opposite the coreengaging surface, initially closing the bottom end of the mold, pouring ingot metal into the mold space whereby it bonds to the spacer members and solidifies within the mold and around the core, effecting downward movement of the solidified metal with the integrated spacer members concurrently with the continued pouring of liquid ingot metal, exerting a retarding effort upon the spacer members as they pass downward into the mold so that the downward movement of the solidified metal exerts a tension effect along the parts of the spacer members within the liquid metal while maintaining the surfaces of the spacer grooves and the core edges in abutment for thereby guiding the spacer members in their downward movement, and withdrawing solidified ingot metal and the integrated spacer members from the cores and thereby providing an empty channel within the ingot of a size and shape determined by the solidification of the metal adjacent the core and whereby the ingot has internal longitudinal discontinuities formed by the said antiwelding films in planes substantially at right angles to the said first plane and each at a distance from the adjacent part of the channel determined by the distance from the bottom of the respective spacer groove to said film on the respective spacer.
2. The method as in claim 1, in which the cores have edges formed by convergent surfaces, and the grooves in the spacer members are of corresponding cross-section for guidedly engaging the said convergent surfaces at the core edges.
3. The method as in claim 1, in which the cores have edges of rounded cross-section, and the grooves are of corresponding rounded cross-section for guidedly engaging the said rounded core edges.
4. The method as in claim 1, in which a plurality of spaced permanent cores are employed, and spacer members of the bond-integrating metal are placed between each two adjacent cores, the spacer members having grooves in their faces for guidedly receiving the edges of the said adjacent cores and being held in abutment with the cores.
5. The method as in claim 4, in which a spacer member present between and in abutment with two adjacent cores is formed in two parts in abutment with an antiwelding film therebetween and each having a groove for receiving the edge of the respective core, whereby the formed ingot has a said internal discontinuity provided therein between said channels and with said discontinuity spaced at distances from the adjacent channels formed by the said adjacent cores predetermined by the distances from the respective groove surface to the said film.
6. The method as in claim 5, in which edge pieces are provided, and including the employment of end spacer members between the free edges of the lateralmost cores and the respective end pieces, with the end pieces presented in abutment with the end spacer members and are integrated by bonding with the solidifying ingot metal, and are lowered concurrently during the downward movement of the solidified part of the ingot, and in which anti-welding material is present at the abutting surfaces of the end spacers and end pieces.
7. An apparatus for making an ingot having an inter nal longitudinal channel, comprising a casting mold open at top and bottom, a platform for initially closing the lower end of the mold and means for controlling the downward movement thereof with the solidified parts of an ingot supported thereon, means on the platform for engaging and locating the lower ends of spaced preformed metal pieces to be integrated into the ingot, a support above the upper end of the mold, a fixed core mounted on the support and extending downward into the mold for contact by molten ingot metal therein, said core being tapered convergently downward at an angle coordinated to the shrinkage of the ingot metal in solidifying and moving downward along the core, the core support having openings through which the preformed metal pieces can move and thence along the fixed core during the descent of the platform, guide means for the said pieces and mounted above the support and including rollers engaged with the pieces for urging them into contact with the edges of the fixed core, and means for pouring ingot metal into the mold and around the core and metal pieces.
8. An apparatus for making an ingot having a plurality of internal longitudinal channels, comprising a casting mold open at top and bottom, a platform for initially closing the lower end of the mold and means for controlling the downward movement thereof with the solidified parts of an ingot supported thereon, means on the platform for engaging and locating the lower ends of spaced pre-formed metal pieces to be integrated into the ingot, a support above the upper end of the mold, a plurality of fixed cores mounted in a row on the support and extending downward into the mold for contact by molten ingot metal therein, each said core being tapered convergently downward at an angle coordinated to the shrinkage of the ingot metal in solidifying and moving downward along the core, the cores being at intervals and spaced apart in the row by the corresponding dimension of the metal pieces and having their horizontal crosssections reduced at lateral edges for engagement with conformed surfaces of the pre-formed metal pieces, the core support having openings respectively aligned with the intervals between adjacent fixed cores and through which the pre-formed metal pieces can move and thence 10 move along the fixed cores during the descent of the platform, guide means for the said pieces and mounted above the support and including rollers engaged with the pieces for urging them into contact with the edges of the fixed cores, and means for pouring ingot metal into the mold and around the cores.
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