US3554271A

US3554271A - Molding assembly method

Info

Publication number: US3554271A
Application number: US713895A
Authority: US
Inventors: Harold R Goss
Original assignee: Acme Cleveland Corp
Current assignee: ROBERTS Corp A MI CORP; Roberts Corp
Priority date: 1968-03-18
Filing date: 1968-03-18
Publication date: 1971-01-12
Anticipated expiration: 1988-01-12
Also published as: DE1913077A1; FR1601367A

Abstract

The disclosure relates to a method of making and the apparatus of a molding assembly for use in a casting process. The molding assembly may be used in casting molten metal in a mold of sand or other refractory material. A drag and a cope mold are each prepared in a similar manner with the drag mold being built up on an assembly plate from an assembly of building blocks each of which may be a mold/core block of sand held together with a binder and made in a core making machine. The building blocks nest together and form the internal core parts as well as the external mold parts of the molding assembly. These building blocks are backed by mechanical means or by a flask and rammed or slung sand. The cope assembly is made in a similar manner. Next the drag assembly is inverted and the assembly plate removed and then the cope assembly is placed on top. A pouring sprue opening and gating system is contained entirely within the building blocks of either the mold or the core portion of the assembly so that sand inclusions do not appear in the casting. Also no pattern is at any time drawn from the mold.

Description

United States Patent [72] lnventor Harold R. Goss Richmond Heights, Ohio [211 App]. No. 713,895 [22] Filed Mar. 18, 1968 [451 Patented Jan. 12,1971 [73] Assignee Acme-Cleveland Corporation a corporation of Ohio [54] MOLDING ASSEMBLY METHOD 18 Claims, 5 Drawing Figs.

52 Us. or; 164/137, 164/27, 164/30, 164/340, 164/365 511 1nt.CI B22d 33/04 [50] Field ofSearch 164/19, 20, 21, 22, 23, 27, 28, 29, 30, 31, 32,137, 228, 340, 370, 397, 339, 341, 234, 369, 364, 365, 366, 368; 264/219, 221

[56] References Cited UNITED STATES PATENTS 2,783,510 3/1957 Dolza et al... 164/137 3,010,166 11/1961 Skoning 164/29 3,220,071 1 1/ 1965 Dettore 164/28 Primary Examiner-J. Spencer Overholser Assistant ExaminerJohn E. Roethel Attorney-Woodling, Krost, Granger and Rust ABSTRACT: The disclosure relates to a method of making and the apparatus of a molding assembly for use in a casting process. The molding assembly may be used in casting molten metal in a mold of sand or other refractory material. A drag and a cope mold are each prepared in a similar manner with the drag mold being built up on an assembly plate from an assembly of building blocks each of which may be a mold/core block of sand held together with a binder and made in a core making machine. The building blocks nest together and form the internal core parts as well as the external mold parts of the molding assembly. These building blocks are backed by mechanical means or by a flask and rammed or slung sand.

' The cope assembly is made in a similar manner. Next the drag assembly is inverted and the assembly plate removed and then the cope assembly isplaced on top. A pouring sprue opening and gating system is contained entirely within the building blocks of either the mold or the core portion of the assembly so that sand inclusions do not appear in the casting. Also no pattern is at any time drawn from the mold.

BACKGROUND OF THE INVENTION In a typical mold-assembly for casting molten metal, a cope and a drag are provided of sand or other refractory material held together with some type of binder. The drag and cope are made separately in mold making machines, with patterns being placed in a flask and then the sand and binder slung or rammed inplace around the pattern. The patterns are drawn from the cope and drag flasks. The cope mold may be inverted on to the drag mold and the assembly is then ready for pouring the casting metal. If hollow parts are-to be cast, then cores must be set in place in the drag mold and usually held in place by close fitting print areas in the cope and drag molds. As more complicated shapes are attempted to be cast, additional cores must be set in place and often the operator must reach down inside the drag mold to carefully place the core into a print area of the drag mold. This is quite an old manner of making such cast articles with apertures therein, such as shown inthe Drake et. al. U.S. Pat. No. 524,543 of l 894.

With increasing complexity of the article to "be cast it becomes increasingly more difficult "to place the required cores in the print areas without damaging either the cope or the drag. The previous practice in such cases was to make the cores as separate parts and then the cores were pasted together. This took considerable skill on the part of the operator to make sure that the cores fit tightly together and this was very important as any metal which penetrated between the cores had to be later cleaned from the casting thereby again increasing costs.

It has been known to provide a composite core made from a number of parts assembled and pasted together and then this composite core set in a greenjsand or oil sand drag mold, with the composite core temporarily retained. by a jig or core setting fixture to align the core in the drag mold. Later a green sand or oil sand cope mold is placed on the drag mold to provide a mold assembly for receiving the casting metal. However, in such case the gating system and-vent apertures are partially in the green sand or oil sand and there is still a pattern to be drawn from the cope and drag molds.

Accordingly it is the objectof the invention to provide a method of assembling a mold assembly of both mold and core building blocks which eliminate an operator having to reach down inside the drag mold to fit the cores in place.

Another object of the invention is to provide a mold as sembly constructed of refractory building blocks which may be assembled and accurately located on an assembly plate and then backed up toresist the casting pressure.

Another object of the invention is to provide a molding assembly and the method of making it wherein a pouring sprue opening and gating system is contained entirely within mold/core building blocks and not in any loose sand to thus prevent sand inclusions in the cast metal part produced in the molding assembly.

Another object of the invention is to provide a complex molding assembly wherein on no occasion" is a pattern drawn from the mold and hence inaccuracies which occur during the drawing of the pattern are therefore eliminated.

Another object of the invention is to provide a molding system with complete flexibility of the gating system, with 7 freedom to put the gating system down into either the external mold'or the internal core, laterally into the bottom of the cavity or into the midportion of the cavity, and with risers and vents anywhere desired.

Another object of the invention is toprovidea molding system which makes it possible tomake complicated castings on an efficient, production basis, which would have been prohibitively expensive.

Other objects and a fuller understanding of the invention may be had' by referring to the following description and claims, taken in conjunction with thejaccompanying drawing, in which:

FIG. .1 is an isometric view of a complex article to be cast by the present method and apparatus;

castings previously FIG. 2 is an enlarged vertical sectional view of a drag mold assembly;

FIG. 3 is an enlarged vertical sectional view of a cope mold assembly;

FIG. 4 is an enlarged vertical sectional view of the cope and drag assembly to produce the article of FIG. 1; and

FIG. 5 is an enlarged vertical sectional view of an alternative form of drag mold assembly.

SUMMARY The invention may be incorporated in the method of assembling a core and mold in a flask and using an assembly plate, comprising the steps of forming locator means on an assembly plate, forming a plurality of mold and core building blocks of refractory material of the desired shape with some having abutments therein for the locator means and some having sprue apertures, sequentially assembling selected ones of the building blocks on the assembly plate with the abutments engaging the locator means to make a building block assembly with the blocks interengaged, aligning the sprue apertures in a plurality of building blocks to form a pouring sprue opening entirely within said building blocks, and backing the blocks in the building block assembly to form a mold and core assembly to resist outward force of casting pressure.

DESCRIPTION OF THE PREFERRED EMBODIMENT The molding assembly of the invention in the preferred embodiment is that shown in FIG. 4. This molding assembly I l is only one of several embodiments which the apparatus and the method of assemblymay take and the invention is limited not by this preferred embodiment but only by the hereinafter appended claims. The molding assembly 11 of FIG. 4 is designed to make a cast article 12 as shown in FIG. I. This is one example of a fairly complicatedcasting which would require several cores in the conventional molding techniques. It is a part which has a lower flange 13, a tubular body 14, a double flange 15 near the middle and then a conically tapering body portion 16 near the top. There are also several apertures in the cast article 12 which require cores in the molding assembly 1 1.

The molding assembly 11 is started with the drag mold which is formed on a drag assembly plate 20, shown in FIG. 2. This plate 20 may have flask pins 21 for the later location of a flask. At first this flask is not in position on the plate 20. The plate 20 also has locator means such as locator pins or bosses 22. A plurality of building blocks 24 are provided on the assembly plate 20 and on the locator means 22. Each of these building blocks is made from a refractory material with any suitable type of binder. The building blocks 24 may be referred to as core blocks but actually form both the external mold and the internal core so they also may be termed mold/core blocks. Each building block may be made in acore making machine, for example, as a preferred method butsince many have a flat surface, they may also be made'in many types of mold making machines. They may be made of green sand or oil sand, but preferably are made from a sand with athermosetting binder such as that often used for shell molds and cores. The advantage of the thermosettingbinder isthat' it makes a hard, dense, smooth surface core block which will withstand more rough handling than baked oil sand orgreen 'sandcores. Also cold process settable binders may be used such as the carbon dioxide or other gas process'settabletbinders in the building blocks.

A first building block 26 is placed on the locator means 22 and is a mold forming building block. A second building block 27 may be set in place on the central locator pin 22 and this is a core forming cylindrically shaped block. It may be either a solid core or may be a shell core and the other building blocks may be a shell core where appropriate. A third building block 28 next set in place may be a hollow cylindrical core forming block surrounding the block 27 and supported on a print area aperture surrounding the block 28 having recessed locator abutments fitting on the locator pins 32 on the block 26 thus the blocks 30 and 26 interlock by being interengaged at these locator abutments and pins. The locator abutment conveniently may be a circular or annular shoulder of the recess engaging the circular or annular periphery of the locator pin or boss. Next a block 33 may surround the block 28 and rest on the block 30 and can be keyed therewith there at the locator abutments 34. A block 35 rests on the block 33 and is keyed thereto at the locator abutments 36. This block 35 has a print area 37 to receive and accurately locate the upper end of the core block 27. A block 38 may be placed on top of the entire group to complete a drag building block assembly 42.

Next this building block assembly 42 is backed with a backing means 39 to rigidly hold the entire assembly of building blocks together and to form a drag mold and core assembly. This backing means 39 in FIG. 2 takes the form of an open top and open bottom flask 40 which is received over the flask pins 21 and supported on the assembly plate. Next particulate backing material such as dry sand 41 is slung or rammed in place to fill the space between the flask 40 and the building block assembly, to form a drag mold and core assembly 44. This sand 41 may have a small amount of binder such as is customary in oil sand or green sand molds to aid the tight packing of this backing material around the building block assembly. Preferably the exterior portions of the building blocks have projections 43 which key with or interlock with the backing sand to prevent any shifting of any components of the building block assembly during later inversion and handling. One advantage ofa completely dry sand is that there is no binder to be burnt away and hence a minimum of gases will be created. Also the lack of binder will permit a maximum of permeability in this backing material so that gases released by the burning of the binder in the blocks 24 will be readily vented. On the other hand a small amount of binder in this sand 41 will aid the ramming up of the sand and aid the interlocking at the projections 43, yet will not materially decrease the permeability of this backing material 41.

The building blocks 24 in the drag building block assembly 42 are provided in many cases with a sprue aperture 45 which are aligned during the sequential assembly of these building blocks to form a part ofa pouring sprue opening, which will be later described in more detail. A support plate 47 preferably with small perforations 48 for venting may next be placed on the top of the flask 40. The entire drag mold and core assembly 44 may then be inverted and the assembly plate vertically removed, ready for the cope mold assembly.

FIG. 3 shows a second or cope assembly plate 50 having flask pins 51 for a cope flask which is not placed in position until later. This cope assembly plate has locator means 52 to accurately locate a second plurality of building blocks 54. The locator means 52 may be either raised bosses or depressions, and in order to be complementary to the locator means on the drag, these locator means 52 are shown as depressions to receive a corresponding boss on the associated ones of the building blocks 54. In a manner similar to that shown for FIG. 2 the building blocks 54 are sequentially assembled. As an alternative, the building blocks may be assembled directly on the inverted cope mold, rather than being assembled on the assembly plate 50. The building blocks 54 may be formed in a suitable core making machine or mold making machine to form either mold forming parts or core forming parts. First, second, and third building blocks 56, 57, and 58, respectively, may be assembled in that sequence on the assembly plate 50. The blocks 56 and 57 may have locator bosses fitting in the locator means 52 for accurately locating these blocks. The block 56 is a mold forming block whereas blocks 57 and 58 are core forming blocks. The block 56 has a print area 59 to receive the corresponding print area of block 58 to support and accurately locate this block 58.

Block 60 may next be placed on the block 56 and be accurately located thereon by the locator abutments 62. Block 63 may next be placed on the block 60 and accurately located thereon by the print area 64. Block 65 may next be placed on the block 60 and accurately located by the locator abutments 66. The block 65 may also have a print area 67 to help support and accurately locate the block 63. Next blocks 68, 69, and 70 may be sequentially assembled each with locator abutments coacting with the next adjacent block for accurately locating these blocks. The block 69 has a print area 71 to aid in supporting and accurately locating the core block 63. When the last building block 70 has been sequentially assembled, this forms a cope building block assembly 72.

Each of the

blocks

56, 60, 65, 68, 69, and 70 has a sprue aperture 75 which are aligned during assembly to form a pouring sprue opening 76 with a basin 77. This is a part of the gating system for the cavity between the mold and core building blocks. Backing means 79 is provided for this assembly of building blocks and includes an open top and open bottom cope flask 80 resting on the cope assembly plate 50 and located by the flask pins 51. A particulate backing material 81 such as loose sand is slung or rammed in place to fill the space between the flask 80 and the building block assembly 72 and this then forms a cope mold and core assembly 84. The exterior surfaces of the building blocks 54 have projections 83 to interlock with the backing material 81 to help in positively holding together the building block assembly 72 and preventing shifting thereof during handling. Again this backing material 81 may be dry sand for maximum permeability or may have a small amount of binder to aid in the positive locking and support of the building blocks in the assembly 72. The building blocks 69 and 70 have small vent openings or risers 87 which are aligned in the assembly 72. These vent openings lead to the casting cavity inthe mold and core assembly 84 to aid in venting any gases released during the casting process for which the molding assembly is designed.

With the drag mold assembly 44 inverted, as shown in the lower portion of FIG. 4, the cope mold and core assembly 84 may be vertically separated from the cope assembly plate 50 and then transferred onto the drag assembly 44. This will create a complete molding assembly 90'as shown in FIG. 4 ready for the casting operation. In the placing of the cope assembly 84 on the drag assembly 44, the locator means 22 may be designed to be complementary to the locator means 52 so that the cope and drag assemblies 84 and 44 will interlock. Alternatively the cope and drag

flasks

80 and 40 may designed to be complementarily engageable, as by alignment pins 85, to align these two assemblies 84 and 44. Another alternative is to use locking pins 91 in complementary apertures in the building blocks left by the withdrawal of the locator pins. In the complete molding assembly 90 of FIG. 4, it will be noted that the sprue apertures 45 in the drag assembly 44 are aligned with the sprue apertures 75 in the cope assembly 84 in order to form the complete pouring sprue opening 76. In this manner the casting metal is received via the gating system into the casting cavity at the bottom and then rises to fill this casting cavity according to the best casting techniques.

FIG. 5 illustrates a modification of the invention in that a modified form of drag mold and core assembly 95 is achieved. In this FIG. 5 a modified drag assembly plate 96 is used which is not a flat planar plate, instead it has locator recesses 97 and locator abutments 98 to help in accurately locating the plurality of building blocks 99 in the building block assembly 100. In this drag assembly 95 the backing means 101 is not sand plus a flask, instead it is a mechanical backing means which includes a generally boxed shaped frame 102 and holding fingers 103. The holding fingers 103 engage the projections 43 on the exterior surface of the building blocks 99. This backing means 101 has the advantage of providing a maximum permeability of the backing means and still interlocking and with to firmly hold the building block assembly 100. Also in a high volume foundry such as is used in automotive parts foundries, tons of sand are shifted every day and this backing means 101 has the advantage of eliminating the need for the backing sand which otherwise would have to be transported, rammed, shaken out, sifted, rebaked and conveyed for reuse. Still further the small contact areas of the holding fingers 103 establish a minimum chilling of the casting withinthe cavity and thus produce high quality castings.

The FIG. 5 shows only the drag mold but it will be readily understood that the cope mold assembly may be made in the same manner.

The molding assembly 90 has the advantage of using core blocks which are both mold and core blocks which may be sequentially assembled without the

flasks

40 and 80 in place. Thus the assembler has full view of the entire assembly process for quick and accurate assembling of these building blocks. The locator means 22, 32, 34, 36, 52, 62, 66, 97, and 98 permit the rapid and accurate locating of all these building blocks in the assembly. Accordingly complex molds and cores may be rapidly assembled. Because each of the building blocks may be made with a thermosetting or cold setting binders, for example, the cores are accurate and have a minimum of shrinkage and warpage. This means that the blocks will interlock and interflt so that a minimum of metal fins will be produced on the cast metal article 12. This eliminates the time and expense of cleaning the finished casting. Also it will be noted that the pouring sprue opening 76 and entire gating system is contained'withinthe building blocks 24 and 54 and accordingly no part of this gating system is in contact with nor defined by the sand backing '4] or 81. In conventional molding processes part of the pouring sprue opening or gating system is usually contained within the green sand or oil sand portion of the cope or drag mold. By the present invention with the entire gating system withinthe core blocks, the hot metal comes into contact with only the solid coreblockarea, so that the risk of sand inclusions in the casting is reduced to a minimum building blocks 24 and 54 assembled one on top of the other and this is really anexterior placement of these building blocks because the

flasks

40 and 80 are not present during this assembly. This sequential "assembly of the building blocks from the outside or exterior as opposed to reaching down inside of the mold, establishes the casting cavity as formed by both exterior and'internal shapes. Accordingly, creating this molding assembly is extremely rapid compared to the prior art methods of setting core blocks down inside a complicated shape of a drag mold, for example, as shown in U.S. Pat. No. 524,543. In such patent only an extremely simple shape was shown yet this illustrates the difficulty of accurately placing the print area of a core into the drag mold with accuracy and without breaking parts off either the core or the mold. If a chunk of sand is broken off the core or mold, it then falls into the cavity and thus a defective casting will be produced.

The, assembly on the

plates

20 and 50 also permits automation of extremely complex castings such as automotive cylinder blocks, heads etc., while utilizing a minimum of skilled labor. The core blocks could even be numbered so that unskilled laborers could assemble the blocks in sequence. Also the blocks may be mechanically set in place by machincry to completely automate the building of the complete mold and core assembly'44and 84.

The simplicity and accuracy of setting the building blocks permits the

assembly plates

20 and 50 to be passed along a conveyor belt, with operators on one or both sides of the conveyor belt placing the cores in sequence as the assembly passes along the conveyor. This would permit rapid assembly with a minimum of chance for error in the assembly and utilizing unskilled labor.

The FIGS. 2, 3, 4, and 5 show sections through the building blocks 24 and 54 and indicate that these blocks are solid. The section lines may also be taken through a rib with the building blocks being of egg-crate design for lightness and a minimum of sand together with the requisite strength to resist the casting pressure.

Another advantage of the present invention is the ability to eliminate the problem of contamination of the sand by using different binders in the molding sand-for the drag and cope mold, and in the cores. In conventional methods the cores may be built up and pasted together for a complicated castingand the cores may be used with thermosetting binders, for example. However, the drag and cope molds are typically green sand or oil sand which has a different binder. After the metal has been poured for the casting and cooled, the flasks are passed to a shake-out device to break up and shake out the sand of the cores from the interior of the casting. Accordingly all of this sand, both that which was formerly used in the cores and that which was formerly used in the molds are mixed together. Typical foundry practice is to not use this sand again for cores, but to reuse it for the molding sand. This means that the binder used in the cores must be compatible with the binder used in the molding sand; otherwise, gradually the percentage of the core binder increases in the molding sand to the point where it interferes with the proper operation and functioning of the molding sand. With cold-setting or gas setting binders, recently coming into favor, the problem is even worse because the cold-setting binders are less compatible with the molding sand binders than were the thermosetting binders.

The present invention eliminates this problem because the same binder may be used, if any is used at all, in the

backup sand

41 and 81 as is used in the building blocks 24 and 54. This will eliminate the problem of contamination of this backup sand.

Still another advantage of the present system is that the cast metal does not come in contact with any of the backup sand at anytime. It will be noted that the entire gating system is within the building blocks and this'has the advantage that it is not necessary toprocess the backing sand as thoroughly as it is-in conventional molding techniques becausethe danger of contamination of the hot metal from something in the molding sand is eliminated.

The FIG. '5 shows that the building block assembly '42 or 72 may be provided with a mechanical backup rather than the sand and flask backup. Whereas the sand backup is of importance in the jobbing or short run type of foundry, high production foundries such as the automotive foundries will find great advantage in the mechanical backup method of FIG. 5. This mechanical backup greatly reduces the ratio of sand used to metal cast. Whereas today with conventional methods this sand to metal poured ratio could be as high as 30:] of sand to metal, with the present invention this ratio is vastly reduced. The amount of reduction depends entirely upon the type of casting to be produced, however; it can be reduced to 5:1 or even 3.1. This will reduce by many tons the vast amount of sand which is used and continuously reprocessed in a high production foundry.

It will be recognized that literally incalculable different forms of cast articles 12 may be produced so that the preseiit disclosure of a preferred embodiment is only illustrative and is not to be taken as a limitation. The preferred embodiment however does illustrate a generally complex cast-article-which requires several cores, as distinguished from the mold portion, and illustrates how even more complex articles may be cast by the use of the present assembly method and molding apparatus.

The present disclosure includes that contained in the-appended claims, as well as that of the forgoing description. Although this invention has been described in itspreferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangemerit of parts and steps may be resorted to without departing from the spirit and the scope of the inventionas hereinafter claimed.

I claim:

1. The method of assembling a core and mold in a flask and using an assembly plate:

comprising the steps of;

forming locator means on an assembly plate;

forming a plurality of mold and core building blocks of refractory material of the desired shape with some having abutments therein for the locator means and some having sprue apertures;

sequentially assembling selected ones of the building blocks on the assembly plate with the abutments engaging the locator means to make etc., building block assembly with the blocks interengaged;

aligning the sprue apertures in a plurality of building blocks to form a pouring sprue opening entirely within said building blocks; and

backing the blocks in the building block assembly to form a mold and core assembly to resist outward force of casting pressure.

2. The method as set forth in claim 1 wherein the assembly plate is a drag assembly plate and including the steps of inverting the mold and core assembly and removing the drag assembly plate to reveal a drag building block assembly.

3. The method as set forth in claim I wherein said refractory material is adhered together with a binder, and the individual building blocks have complementary shapes to permit interlocking of adjacent building blocks to aid in the sequential assembling of the blocks.

4. The method as set forth in claim! including backing the blocks in the building block assembly and leaving a sprue opening on the top of the assembly to form a cope mold and core assembly accessible from the top for pouring a casting material in the sprue opening.

5. The method as set forth in claim 1 including sequentially assembling selected ones of the building blocks to form a cope building block assembly on the drag building block assembly.

6. The method as set forth in claim 5 wherein said pouring sprue opening is at least partially within the mold building blocks of the cope mold and core assembly.

7. The method as set forth in claim 1 wherein the backing of the blocks includes an open top and open bottom flask and including the steps of placing the open top and open bottom flask on the assembly plate and surrounding the building block assembly, and filling the space between the building block assembly and the flask with a particulate backing material to form a complete mold and core assembly.

8. The method as set forth in claim 7 including placing a perforated support plate on said mold and core assembly, inverting the mold and core assembly, and removing the assembly plate to reveal a drag mold and core assembly.

9. The method as set forth in claim 8 including sequentially assembling selected ones of the building blocks to form a cope building block assembly on the drag mold and core assembly.

10. The method as set forth in claim 9 including aligning the sprue apertures in a plurality of building blocks in the cope assembly with the sprue apertures in the drag assembly to form a pouring sprue opening completely within the mold building blocks of the cope and drag assemblies.

11. The method as set forth in claim 9 including backing the blocks in the cope building block assembly to resist outward force of casting pressure.

12. The method as set forth in claim 9 wherein at least one of the building blocks in the cope assembly has a vent aperture to vent gases released during the casting process.

13. The method as set forth in claim 9 including inserting locking pins in the apertures left by the withdrawal of the locator means.

14. The method as set forth in claim 11 including placing an open top and open bottom flask surrounding said cope building block assembly, and filling the space between the cope building block assembly and the cope flask with a particulate backing material to form a cope mold and core assembly.

15. The method as set forth in claim 14 wherein said locator means are locator pins on the assembly plate: 4

said abutments on the building b ocks are locating apertures;

said building blocks having projections on the rear faces thereof to key into the particulate backing material to prevent shifting of any of the building blocks in the complete mold and core assembly of both the cope and drag assembly;

inserting locking pins in the apertures left by the withdrawal of the locator pins;

forming vent apertures in selected ones of the building blocks; and

aligning the vent apertures in the building blocks to form a vent opening to vent gases released during the casting process. 16. The method as set forth in claim 8 including sequentially assembling selected ones of the building blocks on a second assembly plate to form a cope building block assembly:

backing the blocks in the cope assembly with a particulate backing material containing a binder to form a cope mold and core assembly; and

vertically separating the cope mold and core assembly relative to the second assembly plate and placing the cope mold and core assembly on the drag mold and core assembly with the binder in the particulate backing material retaining the cope mold and core assembly as a unitary structure during such transfer.

17. The method as set forth in claim 1 including sequentially assembling selected ones of the building blocks to form a cope building block assembly;

inverting the said mold and core assembly to form a drag mold and core assembly;

assembling the cope building block assembly on the drag mold and core assembly;

placing flask means around the cope and drag assemblies;

and

filling the space between the cope and drag assemblies and said flask means with a particulate backing material as a part of the backing of the blocks to form a complete cope and drag mold and core assembly.

18. The method as set forth in claim 1, wherein the backing ofthe blocks includes a flask and including the steps of placing the flask surrounding the building block assembly, and filling the space between the building block assembly and the flask with a particulate backing material to form a complete mold and core assembly.

Claims

1. The method of assembling a core and mold in a flask and using an assembly plate: comprising the steps of; forming locator means on an assembly plate; forming a plurality of mold and core building blocks of refractory material of the desired shape with some having abutments therein for the locator means and some having sprue apertures; sequentially assembling selected ones of the building blocks on the assembly plate with the abutments engaging the locator means to make etc., building block assembly with the blocks interengaged; aligning the sprue apertures in a plurality of building blocks to form a pouring sprue opening entirely within said building blocks; and backing the blocks in the building block assembly to form a mold and core assembly to resist outward force of casting pressure.

3. The method as set forth in claim 1 wherein said refractory material is adhered together with a binder, and the individual building blocks have complementary shapes to permit interlocking of adjacent building blocks to aid in the sequential assembling of the blocks.

4. The method as set forth in claim 1 including backing the blocks in the building block assembly and leaving a sprue opening on the top of the assembly to form a cope mold and core assembly accessible from the top for pouring a casting material in the sprue opening.

15. The method as set forth in claim 14 wherein said locator means are locator pins on the assembly plate: said abutments on the building blocks are locating apertures; said building blocks having projections on the rear faces thereof to key into the particulate backing material to prevent shifting of any of the building blocks in the complete mold and core assembly of both the cope and drag assembly; inserting locking pins in the apertures left by the withdrawal of the locator pins; forming vent apertures in selected ones of the building blocks; and aligning the vent apertures in the building blocks to form a vent opening to vent gases released during the casting process.

16. The method as set forth in claim 8 including sequentially assembling selected ones of the building blocks on a second assembly plate to form a cope building block assembly: backing the blocks in the cope assembly with a particulate backing material containing a binder to form a cope mold and core assembly; and vertically separating the cope mold and core assembly relative to the second assembly plate and placing the cope mold and core assembly on the drag mold and core assembly with the binder in the particUlate backing material retaining the cope mold and core assembly as a unitary structure during such transfer.

17. The method as set forth in claim 1 including sequentially assembling selected ones of the building blocks to form a cope building block assembly; inverting the said mold and core assembly to form a drag mold and core assembly; assembling the cope building block assembly on the drag mold and core assembly; placing flask means around the cope and drag assemblies; and filling the space between the cope and drag assemblies and said flask means with a particulate backing material as a part of the backing of the blocks to form a complete cope and drag mold and core assembly.

18. The method as set forth in claim 1, wherein the backing of the blocks includes a flask and including the steps of placing the flask surrounding the building block assembly, and filling the space between the building block assembly and the flask with a particulate backing material to form a complete mold and core assembly.