US2272708A - Flask wall - Google Patents

Description

8 R 0 O s m E 2 7 v w H... NWWQMMWOWMOWQMW M. 00 o wvw A QOQ J v t J. F. HINES FLASK WALL Filed July 20, 1940 Feb. 10, 1942.

ATTORNEY.

Patented Feb. 10, 1942 earn GFICE FLASK WALL Application July 20, 1940, Serial No. 346,627

1 Claim.

This invention relates to foundry flasks of the removable or snap variety, and particularly aims to provide such a flask which can be used without a sand strip, the formation of the inner walls of the flask serving to hold the sand in place. The present application is a continuation in part of my co-pending application Serial No. 307,993, filed December 7, 1939 (now Patent No. 2,224,961, issued December 1'7, 1940), but also embodies certain specific improvements thereon, particularly in the shape of the ribs and indentations of the inner face of the flask wall.

Among the aims of the invention are so forming the ribs and. the indentations therebetween that when the mold is jolted and rammed the sand will readily conform itself thereto and be held thereby against downward movement, thus resisting the tendency to fall out of the flask, and in this way accomplishing by a multitude of shallow holds all over the sides of the molds the same purpose that has previously been accomplished by sand strips.

Further the invention aims to make the ribs of such specific form that although the sand will readily pack tightly against the ribs and into the indentations, nevertheless when th flask is opened the sand will not stick to the ribs or in the indentations, but the flask wall will come away clean and free, leaving a smooth imprint in the mold sides. At the same time the channels left in the mold sides by the ribs provide channels for escape of gas when the mold. is closely jacketed. Also, the protuberances or bosses formed on the mold sides are of a shape not readily broken when the mold is jacketed, because free from sharp edges and sharp corners. An earlier form of this invention for elimmating sand strips is illustrated and described in my co-pending application No. 307,993, but the present rib is an improvement on the one there illustrated.

The accompanying drawing and following description disclose a preferred embodiment of the principles of my invention, thereby illustrating it, but without limiting it to such disclosure.

In the accompanying drawing:

Fig. 1 is a perspective showing cope and drag of a flask of my improved construction, assembled and closed, but empty;

Fig. 2 is a perspective showing the same as Fig. 1, but open;

Figs. 3 and 4 are enlarged vertical transverse sections on the plane 6-6 of Fig. 5, showing respectively the fit of the flask wall against the mold and th flask wall separated from the mold for removal;

Fig. 5 is an enlarged fragmentary inner face view of a flask wall, the drawing being actual size;

Fig. 6 is a vertical section on plane 66 of Fig. 5;

Fig. 7 is a horizontal section on plane 1-4 of Fig. 5;'

Fig. 8 is a horizontal section on plane 88 of Fig. 5;

Fig. 9 is a cross-section through one rib on plane 9-9 of Fig. 5; and

Fig. 10 is a perspective showing a mold made in a flask similar to that of Figs. 1 and 2, although of different proportions and taper, this figure being somewhat diagrammatic in style.

In the description and claim, for uniformity of expression, wall is used to mean either a side or an end of either a cope or a drag, flask section means two walls connected by an immovable corner, flask half means either an entire cope or an entire drag. In the claim flask means either a whole flask or a flask half. My present invention, like that illustrated in my co-pending application Serial No. 307,993, provides a flask which has a lateral opening arrangement whereby a corner can be unlocked and the flask sections thus separated horizontally a short distance, thereby moving the walls slightly away from the mold sides to break the adhesion, the extent of removal being suflicient so that the ribs on the walls will clear the bosses in the sand, all as will readily be seen by comparison of Figs. 3 and 4. The opening and closing mechanism and the means for aligning the flask sections are not illustrated in detail here, but may be of any suitable form, for example as illustrated either in my co-pending application Serial No. 307,993, or in my co-pending application Serial No. 248,668, or otherwise, as here shown.

My invention is illustrated in Figs. 1 and 2 as applied to two flask halves, of which a cope I is assembled on top of a drag 2 by the usual means, here shown as pins 5. Cops and drag are each separable. horizontally into two sections, IA and IB in the cope, 2A and 2B in the drag, at diagonally opposed corners l and 8 for the cope, 9 and ill for the drag. The other pair of corners of each element are permanently immovable, preferably assembled as shown by my Patent No. 2,006,240.

In the present invention, no sand strips are used. The mold is held by a series of shallow ribs I2 in a diagonal criss-cross arrangement, thus forming hollows I4 between the ribs. Each rib has its upper edge I5 directed inward much sharper than its lower edge I6, as shown in a rectangular cross-section of Fig. 9, and as shown in angular sections in Figs. 6, 7, and 8. All the rib edges, and the junctions of the ribs with the bottom of the hollows I4 are slightly rounded to avoid sharp edges to break the sand of the mold. By this formation of the ribs, each of the hollows I4 has a bottom shelf formed by two intersecting flattened edges I5, while at the top the ribs slope very gradually into the wall surface by the wide easy shoulders I6. The foregoing description pertains particularly to the cope, since the flat shoulders I5 must be at the bottom when the cope mold is formed in order to hold the sand. In the drag the relationship is reversed, inasmuch as the drag mold is formed with the drag flask inverted from assembled position. Thus Figs. 5 and 6 are representations from either the cope or the drag as the case may be, but taken in the mold making position. In the drag 2 of Figs. 1 and 2 the shoulders I5 are up.

A mold M formed in my present improved flask, when assembled has the general appearance of Fig. 10, although this figure is in diagrammatic style, and does not attempt to show the actual contour of the bosses I8 in the sand which are the counterparts of the hollows I4. The counterparts of the ribs I2 are the grooves I9 in the mold which among other functions permit escape of gas behind a jacket wall as diagrammatically shown in Fig. 5 of S. N. 307,993.

A further advantage from forming a mold with a large number of bosses and relatively large grooves therebetween on the wall faces is that if there are any bosses I8 higher than the general level, they will be shaved down by the jacket. The grooves afford space for sand so shaved off to lodge, instead of accumulating between the jacket and the mold and tending to crush the mold cavity inward.

Although pressures within the mold when pouring may be heavy, the bosses I8 afford numerous points of support evenly distributed, while the bridging effect of the wet sand carries the pressure across the grooves I9.

From the foregoing it will be seen that I have invented a wall structure or configuration for snap flasks whereby no sand strip is necessary, and whereby a distinct supporting effect is provided at very frequent intervals in the flask against the gravitational tendency of the sand in the mold. At the same time arrangements are made whereby the flask may easily and readily be freed from the mold for removal therefrom. The mold formed in such flask also has specific advantages of its own, as set out above.

The foregoing description is of a preferred embodiment of my invention, and is illustrative rather than limiting. The scope of the invention is to be determined by the following claim.

I claim:

A flask rib having a horizontal directional component, said rib being imposed upon the inner face of a flask wall and having its upper edge junction with the wall substantially flatter than the lower edge junction.

JAMES F. HINES.

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