US2049980A - Hot top - Google Patents

Description

Aug. 4, 1936. E. J. TURNER ET AL 2,049,98Q

HOT TOP Filed Feb. 6, 1934 alHo,

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" 6 swan/0mm Patented Aug. 4, 1936 UNITED STATES PATENT oFFicE HOT TOP Delaware Application February 6, 1934, Serial No. 709,956

1 Claim.

The present invention relates to an improve? ment in hot tops; and more'particularly to an improvement in the hot top shown in the Patent to Turner 1,593,518.

8 The hot top shown .therein has proved advantageous in operation in that the same functions more efliciently in affording a reservoir of-metal which flows into the body of the ingot during solidification of the mass of metal therein. The

10 portion of the metal confined within the hot top which is available to thus flow into the body of the solidifying ingot depends to a large extent upon the insulating properties of the hot top. The hot top disclosed in said patent operates so 15 efliciently to provide a reservoir of molten metal that the required volume within the hot top may be decreased an appreciable amount, thus reducing the amount of metal which must be discarded.

We propose to improve the insulating proper- 20 ties of the hot top by heating up the refractory material of which the hot top is formed before the ingot is completely poured. During the pour- I ing operation, molten metal enters the ingot mold at a temperature upwards of 2900. Of course,

5 the metal entering the mold displaces air which must flow upwardly out of the mold; and during its upward passage this air attains a high temperature. We propose to extend the openings in the side walls of the hot top so as to permit flow of hot 30 gases vertically through these side walls.. The thickness of refractory material surrounding these vertical passageways is small enough so that by the time the ingot is poured and the hot top is, filled with molten metal, the refractory mate- 35 rial has been preheated by the upwardly rising air to a high temperature. At this time the molten metal reaching the lower ends of the passageways freezes therein and seals the same so that the side walls which are now at a high temperature prevent the dissipation of theheat of the reservoir of molten metal within the hot top, the insulating efiect being aided by the air spaces formed in the side walls.

The conservation'of the heat in this molten metal in the hot top is aided by using a top wall or lid shading or sheltering the marginal portions of the top of the mass of metal confined within the hot top. The extent of such protection is obviously determined by the size ofpouring. opening which must be provided in the lid.

In the accompanying drawing which illustrates our invention,

Fig. 1 is a plan view of a hot top with lid, the side walls being formed with vertical passages therethrough;

Fig. 2 is a side view partially broken away on the line II--II of Fig. 1 of the hot top shown in that figure, the top of the ingot mold being shown in chain lines;

Fig. 3 is a view similar to Fig. 1 showing a hot 5 top without lid;

Fig. 4 is a view similar to Fig. 2 showing the form of hot top of Fig. 3 and partially broken away on the line IV-IV of Fig. 3.

The composition of material determined upon for use in manufacturing the hot top may be formed into suitable shape by molding, extrusion, or the like. The hot top is formed with side walls 6 having vertical passages therethrough. This is readily accomplished by providing compound walls comprising an inner shell 8 and an outer shell 9 connected by relatively narrow ribs or webs ill. The above mentioned vertical passages l2 extend through the side walls 6 from bottom to top, and are adapted to permit flow of hot gases upwardly through the walls of the hot top as the molten metal is poured into the ingot mold iii.

In the form of hot top shown in Figs. 1 and 2 a marginal top wall or lid i5 surmounts the side Walls 6, the lid l5 terminating short of the outer 5 shell 9 so as to afford free passage for gases rising through the passages l2. .In the embodiment shown in the drawing the borders of the lid are restricted so as not to overlie the passages I 2. The lid should be so arranged that its edge portions are in spaced relation to the outer side' wall or shell 9; and accordingly these edge portions of the lid should be upturned if they extend outwardly in an appreciable amount over the passages l2. The lid I5 is provided with a pouring opening l6 such as is required to admit the stream of molten metal. In the form of hot tops shown in Figs. 3 and 4, the lid 15 is omitted.

The hot top may be positioned in the desired relation to the top of the ingot in any suitable 40 fashion. In the form of vhot top shown in Fig. 2 we have provided the same with cut-outs l8; and the hot top is blocked up at the desired level by blocks i9 resting on the top of the ingot mold l3 and having their upper inner edges entered in the cut-outs I8. In the form of hot topshown in Figs. 3 and 4, ribs 20 integral with the sine wall of the hot top are formed in the course of manufacture of the hot top; and these ribsengage blocks 2i of suitable thickness which are supported by the top of the ingot mold l3. It will thus be understood that the means for supporting the hot top may comprise lugs, ribs, cut-outs or any other convenient type of support.

The advantages of the present invention arise 5 in part from the higher temperature at which it is possible to maintain the mass of metal in the hot top during the time that solidification is taking place within the ingot mold proper.

While we have illustrated and described certain preferred forms of our invention it will be understood that the contour, composition and other incidents to the formation of the hot top may be modified; and that accordingly the invention may' be otherwise embodied and practiced within the scope of the following claim.

We claim:

As an article of manufacture, an ingot mold hot top formed with compound side walls comprising inner and outer shells of refractory material connected by ribs or webs providing air spaces therebetween which spaces are open at both the top and the bottom, and a lid integral with the top of the inner shell, said lid having a central pouring opening and terminating in spaced relation to the outer shell to leave open the tops of said air spaces.

ERNEST! J. TURNER.

WILLIAMA'I'URNER.

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