US2718041A - Frangible expendable mold and pouring opening protective device - Google Patents

Description

P 0, 1955 w. L. GEORGEN FRANGIBLE EXPENDABLE MOLD. AND POURING OPENING PROTECTIVE DEVICE Filed March 4 1954 INVENTOR WEND'ELL L. GEORGEN @H Q 0 ATTORNEY Unite States Patent FRANGIBLE EXPEND'ABLE MOLD POURING OPENING PROTECTIVE DEVICE Wendell L. Georgen, Chicago, Ill, assignor to International Harvester Company, a corporation of New Jersey Application March 4, 1954, SerialNo. 414,195

4 Claims. (Cl. 22-90) This invention relates to expendable molds and particularly to a type of mold generally known in the foundry art as shell molding. More particularly this invention relates to a shell mold having a protective device designed to protect the frangible mold.

In the art known as shell molding the mold cope and drag members are made-of a relatively thin frangible shell. The cope and drag are generally suitably connected together, contiguous adjacent surfaces of the cope and drag member forming a cavity into which the cast metal is introduced to make the desired part. In the casting operation the cope and drag parts of the shell mold which are connected together are positioned in upright relation with respect to a mold box or container. Prior to the casting or pouring operation the container is filled with minute shot pellets or other finely divided high density material which serves to support the outer sides of the cope and drag members during the casting operation. The shot that may be utilized can be of a similar type that may be used in a shotpeening or blasting operation. The shot is of course relatively dense and adequately supports the outer surfaces of the relatively thin frangible mold during the casting operation. The use of shot is also desirable since it is well equipped to permit the escape of gases which result as the cast metal is introduced into the mold. After the casting operation has been completed the cope and dragparts, being of a frangible material and expendable, are merely broken oif from the cast part.

The cope and drag members generally also include an elongated passage which is in communication with the interior cavity. This passage is provided with anopening which is positioned along. the upper edges or marginal portions of the cope and drag. It is into this pouring opening that the molten metal flows during the casting operation. Generallyafter the molds have been placed in the upright position within the container, the shot is introduced or poured into the container for supporting the molds. Since? the molds are of a very frangible nature it has generally been found that the pouring edges, that is the edges surrounding the pouring opening, would become considerably damaged and would soon break away thus impairing the metal pouring operation. Furthermore, particles of shot material might be directed into the pouring opening thus producing undesirable results during the pouring of metal. It is a primary object of this invention therefore, to provide an improved shell mold having provisions for protecting the opening and adjacent edges of the mold during the entrance of shot into the mold box.

Still another object is to provide an improved combination of a shell mold and a protective stopper which may be placed over the pouring opening of the shell mold during the entrance of shot into the mold box, prior to a casting operation.

These and further objects will become more readily apparent from the reading of this specification when ice 2. examined in connection with the accompanying sheetof drawing.

In the drawing:

Figure 1 is a perspective view of a mold box having a pair of shell molds disposed therein just prior to ametal pouring or casting operation;

Figure 2 is a cross-sectional view of a portion of a mold and-protective device therefore taken substantially along the line 22 of Figure 1;

Figure 3 is a cross-sectional view through a portion of a mold and protective device taken along the line 3-3 of Figure 2;

Figure 4 is an elevational view of a cope and drag of a shellmold.

Referring now particularly to Figure 1 a mold box is generally designated by the reference character 10. The mold box 16- consists of upright members 11 suitably connected together to form a container or box assembly. All details of the box 10 have not been shown since devices of this type are common in the art. The mold box 10 has disposed therein two molds generally designated by the reference character 12. The molds 12 are of the type which are generally known in the art as shellmolds. Shell molds generally consist of a cope 13' and drag1'4, these members consist-ing of a baked resinous or frangible material. As shown in Figure 4, the cope 13 comprises an inner surface 15 having a cavity 16 formed by a complementary surface of the drag 14. The cavity 16 is of course the chamber which receives the molten or cast metal and which has the desired configuration to produce the cast part desired. The cavity 16 is in communication with a'recessedpassage 17 formed in the cope 13' and drag 14. The passage 17 is provided at one end with a pouring. cup 18 opening outwardly by means of an opening 19. The opening 19 is positioned along upper marginal portions or upper ends of the cope 13 and drag 14. The cope and drag may be suitably connected together by means of staples 20 as indicated in Figure 1.

'As" mentioned above, the opening 19 is positioned along the upper marginal edges of the mold 12. Cutouts or indentations 2'1 and 22 are provided in the upper edges of the cope and drag members on opposite sides ofthe opening 19.

A pouring cup protective device or stopper is generally indicated by the reference character 25. The stopper 25 comprises abody 26 which is generally tapered to fit the funnel-shaped pouring cup 18 of the passage 17'. The protective device 25may be made of a resilient material such as sponge rubber so that the body 26 may be resiliently positioned within the pouring cup 18. The stopper 25 includes an annular flange 27 which extends outwardly from the body '26 and overhangs portions of the frangible mold 12; The flange 27 also includes an annular downwardly turned lip 28 which engages the indentations 21 and 22' in nesting or mating relation. The lip 28' is laterally spaced from the body 26 so as to overhang portions of the cope and drag 13 and 14 positioned adjacent the opening 19.

As indicated in Figures 2 and 3, after the molds 12 have been placed in the upright position within the box 10 it is then necessary to add the shot material which will support the molds 12 and which will permit the venting of gases from the molds during the casting operation. Prior to the pouring of the shot into the box 10, the stopper 25 is suitably wedged into each pouring opening 18 with care being taken that the lip portions 28 nestle within the indentations 21 and 22 as indicated. The shot may now be poured into the mold box 10 and the frangible portions adjacent the pouring cup 18 are suitably protected from the entrance of the shot. Thus after the shot has been placed in the box, the protective member 25 can be removed and an uninjured and undamaged pouring opening is provided for the entrance of molten metal into the frangible mold.

Thus it can be seen that an improved shell mold and protective device therefore has been disclosed. The objects of the invention are thus fully achieved and it must be understood that changes and modifications may be made without departing from the spirit of the invention as disclosed or the scope thereof as defined in the appended claims.

What is claimed is:

1. In combination, a mold box, an expendable mold positioned in said box, said mold comprising a pair of upright frangible members having surfaces positioned in contiguous relation, means for securing said frangible members together, recessed portions in said surfaces positioned in complementary relation to provide a cavity for receiving molten casting material, a pouring passage in said frangible members in communication at one end with the cavity, said passage having an opening at its other end disposed adjacent the upper edges of said frangible members, first and second indentations in the upper edges of each of said frangible members, said first and second indentations being disposed on opposite sides of said opening, a stopper over said opening, said stopper including a body portion conforming in general to a portion of the pouring passage and being supported therein, a flange on said body, and an annular lip on said flange, said lip being laterally spaced with respect to said body and being nested in the indentation of said frangible members whereby said opening and passage are protected from fragments of material which may be poured into said box for supporting portions of the mold during a casting operation.

2. In combination, a mold box, an expendable mold positioned in said box, said mold comprising a pair of upright frangible members having surfaces positioned in contiguous relation, means for securing said frangible members together, recessed portions in said surfaces positioned in complementary relation to provide a cavity for receiving molten casting material, a pouring passage in communication at one end with the cavity, said passage having an opening at its other end disposed adjacent the upper edges of said frangible members, first adjacent and second adjacent indentations in the upper edges of each of said frangible members, adjacent indentations of each member being in lateral alignment, said first and second indentations being disposed on opposite sides of and adjacent to said opening, a stopper of resilient material over said opening, said stopper including a body portion conforming in general to a portion of the pouring passage and being telescopingly supported therein, a flange on said body, and an annular lip on said flange, said lip being laterally spaced with respect to said body and being nested in the indentations of said frangible members whereby said pouring passage is protected from fragments of material which may be poured into said box for supporting the mold during a casting operation.

3. In combination, a mold box, an expendable mold positioned in said box, said mold comprising a pair of upright frangible members having surfaces positioned in contiguous relation, means for securing said frangible members together, first recessed portions in said surfaces positioned in complementary relation to provide a cavity for receiving molten casting material second recessed portions in said surfaces positioned in complementary relation to provide a pouring passage in communication at one end with the cavity, said passage having an opening at its other end disposed adjacent the upper edges of said fragible members, first and second indentations in the upper edges of each of said frangible members, said first and second indentations being disposed on opposite sides of and adjacent to said opening, a stopper of resilient material over said opening, said stopper including a body portion conforming in general to a portion of the pouring passage and being supported therein, an overhanging flange on said body, and an annular lip on said flange, said lip being laterally spaced with respect to said body and being nested in the indentations of said frangible members whereby said opening and passage are protected from fragments of material which may be poured into said box for supporting portions of the mold during a casting operation.

4. In combination, a mold box, an expendable mold positioned in said box, said mold comprising a pair of upright frangible members having surfaces positioned in contiguous relation, means for securing said frangible members together, first recessed portions in said surfaces positioned in complementary relation to provide a cavity for receiving molten casting material, second recessed portions in said surfaces positioned in complementary ielation to provide a pouring passage in communication at one end with the cavity, said passage having an opening at its other end disposed adjacent the upper edges of said frangible members, first adjacent and second adjacent indentations in the upper edges of each of said frangible members, adjacent indentations of each member being in lateral alignment, said first and second indentations being disposed on opposite sides of and adjacent to said opening, a stopper of resilient material over said opening, said stopper including a body portion conforming in general to a portion of the pouring passage and being supported therein, an overhanging flange on said body, and an annular lip on said flange, said lip being laterally spaced with respect to said body and being nested in the indentations of said frangible members whereby said opening and passage are protected from fragments of material which may be poured into said box for supporting portions of the mold during a casting operation.

References Cited in the file of this patent UNITED STATES PATENTS 1,939,479 Williams Dec. 12, 1933 FOREIGN PATENTS 668,821 Great Britain Mar. 26, 1952 OTHER REFERENCES Page 115, The Iron Age, November 15, 1951.

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