US2835943A

US2835943A - Ingot mold hot top

Info

Publication number: US2835943A
Application number: US596876A
Authority: US
Inventors: Robert E Daley
Original assignee: Individual
Current assignee: Individual
Priority date: 1956-07-10
Filing date: 1956-07-10
Publication date: 1958-05-27
Anticipated expiration: 1975-05-27

Description

y 27, 1953 R. E. DALEY 2,835,943

INGOT MOLD HOT TOP Filed July 10, 1956 I L Y /A/L- 1 20 26 /7 30 3/ /2 /2 4% 5 6 7 INVENTOR.

, fl/fs 1927-064 2;

rates This invention relates to hot tops for ingot molds, and more particularly to the bottom rings for hot tops and to the manner in which they are attached to the hot top casings.

Connected to the bottom of the usual hot top casing is a refractory ring that is inserted in the top of an ingot mold to protect the lower end of the casing from the molten metal and also to help retard cooling of the adjoining metal. This ring stays with the ingot when the hot top is removed. Because the inner diameters of ingot molds vary to some extent, the hot top bottom rings are made small enough to freely enter the smallest molds with which they are to be used, and then the space between the bottom ring and the surrounding wall of the mold as generally been restricted by a sheet metal ring carried by the bottom ring. When the mental being poured into a mold reaches this ring, pouring is discontinued until the metal is chilled enough to prevent it from rising up into the space between the hot top and the sur rounding mold. It requires a considerable amount of time to fasten the sheet metal ring to the hot top and, of course, the ring is just one more element that has to be provided and handled.

It is among the objects of this invention to provide a hot top which has a refractory bottom ring detachably connected to it in a simple manner. Other objects are to provide such a bottom ring which will snugly fit into molds diifering somewhat in size, which will help center the hot top in a mold, and which does not require a sheet metal ring to seal the space between the refractory ring and the mold.

In accordance with this invention, a bottom ring is detachably connected to the lower end of a metal casing of a hot top, preferably by engaging detents and spring clips. The ring is made principally of refractory material and projects laterally outward beyond the hot top casing. The laterally projecting portion of the ring has a downwardly and inwardly inclined surface that will engage the inner edge of the ingot mold when the ring is lowered into it. The outermost area of the ring beyond its line of engagement with the edge of the mold is displaceableby the mold to permit the ring to slide downward in engagement with the inside of the mold. This displacement may be produced by the breaking off of a peripheral portion of the ring, or by making the peripheral area of the ring from a compressible material. In either case, the ring will engage the inside of the mold and thus prevent molten metal from rising between the ring and the mold.

The preferred embodiment of the invention is illustrated in the accompanying drawings, in which Fig. 1 is a central vertical section through a hot top about to be lowered into an ingot mold;

Fig. 2 is a plan view of the bottom ring;

Fig. 3 is an enlarged fragmentary section showing the hot top inserted in the mold; and

Figs. 4, 5, 6 and 7 are fragmentary vertical sections through bottom rings illustrating four different modifica- 2,835,943 Patented May 27, 1958 tions of the invention, these rings also being provided with spring clips that are not shown.

Referring to the drawings, a hot top metal casing 1 has an inwardly projecting ledge 2 at its lower end which supports the usual refractory lining 3. Projecting up into this casing is the central upper part of a bottom ring 4 that also extends outward'beneath the metal casing. The ring fits against the bottom of the casing and the downwardly flaring surface of the ledge, and the adjoining upwardly extending surfaces of the ring and ledge are provided with means for detachably connecting the ring to the casing. Preferably, these include detents or bosses projecting from one of the members and spring clips carried by the other member for gripping the bosses. Most suitably, the bosses 6 are integral with the metal casing and project inward from it at a number of points around its circumference. The spring clips 7 are metal strips of spring metal, one end of each of which is embedded in the bottom ring. The exposed portion of the strip extends upward and is curved to hook over the adjoining boss. To permit the clip to bend away from the boss when the ring is attached to the casing or removed from it, a pocket 8 may be formed in the ring behind each clip. The clip can be stiffened by punching a tongue 9 out of it and bending the tongue back against the ring so that it will resist inward bending of the clip. It will be seen that it is a very simple matter to connect the ring to the hot top casing by merely pressing the two together so that the spring clips Will snap over the bosses. In some cases the bttom ring can be made in one piece. In others it will have to be made in segments as shown, and they can be connected together by dowels It at their ends.

The bottom ring is made principally, if not entirely, of suitable non-metallic refractory material for well-known reasons. In most, if not all, cases the refractory material will include a sand base. A satisfactory ring has been formed from a mixture of sand, a small amount of clay, and a binder such as sodium silicate. An extender, such as pitch or a resin, may also be used. To reduce the weight of the ring, a light weight filler may be included in the mixture. The ring is molded and then fired without fusing the sand. However, contrary to the practice heretofore, the refractory ring projects laterally beyond the outside of the metal casing 1 far enough to overlap the top of the ingot mold 12, with which the hot top is to be used. In other words, the ring originally is too large to be inserted in the mold. Insertion is accomplished, nevertheless, by pressing the ring down against the surrounding inner edge of the mold in order to displace the overlapping area of the ring and allow the ring to slide down into the mold in engagement with its inner surface. With the ring shown in Figs. 1, 2 and 3, this displacement is caused by the breaking or shearing off of the excess material in the outermost area of the ring, as indicated in Fig. 3. To restrict such breaking to the peripheral area, the area of the ring beyond its line of engagement with the mold edge should have less thickness than the rest of the ring so that it will be weaker. This can be accomplished by providing the portion of the ring that projects beyond the hot top casing with a downwardly and inwardly inclined surface 13. Preferably, the projecting portion of the ring is tapered radially outward so that its upper surface also is inclined. Consequently, when the ring is pressed down into the mold by the receipt of the hot top, the portion that is broken off will be triangular in cross section and much thinner vertically than the remaining portion of the ring. The rest of the ring will slide down into the mold in fairly snug engagement with the inner surface of the mold, so metal will not be able to rise up between the ring and the mold. After the metal has solidified, the hot top casing can be raised, but the ring will remain attached to the ingot. pull away from spring clips 7.

Another advantage of inclined surface 13 is that it is a great help in guiding the hot top into the ingotmold and centering it therein, especially since the ring islarger than the opening in the mold. By having the inclined surface, which means that the lower part of the ring is tapered downward, the lower end of the ring can be made smaller than the mold opening to facilitate its insertion in the mold. Once the ring starts into the mold, the ring taper will center the ring.

In the modification shown in Fig. 4, the projecting portion of the bottom ring 15 is formed of a digerent material 16 than the body of the ring. The peripheral material 16 is compressible, so the outside of the ring is not broken off when the hot top is lowered, but is merely compressed enough to permit the ring to slide down into the mold 12. A number of materials can be used for this purpose, such as glass wool, hemp, various other fibrous materials, asbestos or steel wool. he compressible material is molded into the ring when the ring is formed. Although the compressible material may be burned away by the molten metal in theingot mold, that will not happen before the molten metal at the outer edge of the ring has solidified enough to prevent it from escaping from the mold around the ring. In some cases the peripheral material may be a combination of compressible material and one that will chalk away as the ring is lowered into the mold, or it may be a chalking material only, such as plaster of Paris containing suitable fibres for strength.

The bottom ring 20 shown in Fig. 5 has a lower portion defined by a vertical surface that is spaced from the wall of mold 12. Above this lower portion the ring projects out beyond casing 1 to overlap the top of the mold. The thin projecting portion has an inclined surface 21 engaging the edge of the mold. The triangular section of the ring above the top of the mold will break off when the hot top is lowered, and the ring will slide down into the mold.

In Fig. 6 the full thickness of the bottom ring 25 beyond the hot top casing is tapered downward. The ring; can be inserted farther into the mold, than the one shown in Fig. 1, before the inclined surface 26 will engage the edge of the mold.

The embodiment of the invention shown in Fig. 7 is similar to Fig. 1, but the radially tapered projecting portion 30 of the bottom ring 31 is spaced from both the top and bottom of the ring by. substantially vertical surfaces.

It will be observed that with none of my bottom rings is it necessary to use sheet metal chilling rings, because my refractory rings themselves engage the surrounding wall of the mold.

According to the provisions of the patent statutes, I have explained the principle of my invention and have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

1. A hot top for partialinsertion in the top of an ingot mold, comprising a metal casing, a refractory lining therefor, and a molded non-metallic bottom ring detachably connected to the lower end of the casing, said ring being made principally of refractory material and projecting laterally outward beyond the casing, the laterally projccting portion of the ring having a downwardly and inwardly inclined Surface adapted to engage the inner edge of the mold when the ring is lowered into it, the outermost area of the ring being made of compressible material displaceable by the mold to permit the ring to slide downward in engagement with the inside of the mold.

2. A hot top for partial insertion in the top of an ingot mold, comprising a metal casing, a refractory lining there- Bosses 6 will for, and a molded non-metallic bottom ring detachably connected to the lower end of the casing, said ring being made principally of refractory material and projecting laterally outward beyond the casing, the periphery of the ring being tapered radially and adapted to engage the inner edge of the mold when the ring it lowered into it, the portion of the ring outside of its line of contact with the mold being displaceable by the mold to permit the ring to slide downward in engagement with the inside of the mold.

3. A hot top for partial insertion in the top of an ingot mold, comprising a metal casing having an inwardly projecting ledge at its lower end, a refractory lining supported by the ledge, a plurality of integral projections around the inside of said ledge, a molded nonmetallic bottom ring beneath the casing and extending up into said ledge, and spring clips mounted in the ring and engaging said projections to suspend the ring from the casing, the ring being made principally of refractory material and projecting laterally outward beyond the casing, the periphery of the ring being tapered radially and adapted to engage the inner edge of the mold when the ring is lowered into it, the outermost area of the ring being made of compressible material to permit the ring to slide down into the mold.

4. A bottom ring for a hot top, said ring being formed principally of moldable non-metallic refractory material and having its periphery provided with a downwardly and inwardly inclined surface, the portion of the ring that includes said surface being formed at least in part of compressible material.

5. A bottom ring for a hot top, said ring being formed principally of moldable non-metallic refractory material and having its periphery provided with a downwardly and inwardly inclined surface, the portion of the ring that includes said surface being formed at least in part of compressible material, the central portion of the ring extending upward, and spring clips mounted in the outer surface of said upwardly extending portion for detachably connecting the ring to a hot top casing.

6. A hot top bottom ring adapted to be inserted in an ingot mold of predetermined size, the ring being formed principally of moldable non-metallic refractory material and having a large enough diameter to overlap the top of the mold before insertion therein, the overlapping portion of the ring being formed principally of a compressible material to permit the ring to be pushed down into the mold.

7. A hot top bottom ring adapted to be inserted in an ingot mold of predetermined size, the ring being formed principally of moldable non-metallic refractory material and having a large enough diameter to overlap the top of the mold before insertion therein, the periphery of the ring being provided with a downwardly and inwardly inclined surface adapted to engage the inner edge of the mold when the ring is lowered into it, the mold-overlapping portion of the ring being displaceable by the mold to permit the ring to slide downward in engagement with the inside of the mold.

References Cited in the file of this patent UNITED STATES PATENTS 1,454,742 Howard et al. May 8, 1923 1,500,744 Howard et al July 8, 1924 1,738,209 Rowe Dec. 3, 1929 1,804,204 Charman May 5, 1931 1,804,206 Charman et al. May 5, 1931 2,261,289 Rowe Nov. 4, 1941 2,287,772 Anthony June 30, 1942 2,433,803 Woodworth Dec. 30, 1947 2,465,977 Marburg Mar. 29, 1949