US1863574A - Support for hot tops - Google Patents

Description

June 21, 1932. E MESSLER 1,863,574

SUPPORT FOR HOT TOPS Filed July 31, 1931 INVENTOR 511W!) 7%Wivr Patented June 21, 1932 EUGENE L. MESSLER, OF PITTSBURGH, PENNSYLVANIA surronr FOR nor 'rors Application filed July 31,

My invention relates to the mounting and use of hot tops on ingot molds during the teeming and solidification of ingots.

In order to obtain to the'fullest extent the heat-conserving advantages of a hot top, and to avoid possibility of causing a hanging ingot, it is desirable that a hot top,-which 1 has been initially supported on the upper edge of an ingot mold, be permitted to sink into the mold cavity during solidification and contraction of the ingot.

My invention provides for the mounting and accurate positioning of the hot top during teeming; and for the spontaneous release of the hot top during solidification of the ingot metal, so that it floats upon, and sinks with the contraction of, the ingot metal in the mold cavity. r

My invention further permits the use of hot tops of such simple contour, and such positioning with respect to theingot mold and its cavity, that in the majority of instances the hot top is not gripped and cracked by the contracting ingot metal.

In the accompanying drawing Figure I is a plan view showing a form ofhot-top supporting structure for effecting my object; Figure II is a side elevation of the same, indicating the positioning of a hot vertical sectional view mold and through a hot on in accordance with ing the position of the hot top immediately after teeming; Figure IVis a similar view showing'the position of the hot top in the ingot mold cavity after the hot top supporting means have disintegrated under the temperatures existent during and immediately through an ingot top mounted theremy 1i1vent1on,showview of a slightly modified form of hot top supporting structure; Figure VI is a side elevation of the same; Figure VII is a fragmentary sectional viewon an enlarged scale, showing the details of the supporting structure, and illustrating the manner in which a hot top is supported thereon; and Figure VIII is a similar view illustrating a disintegration of the structure suflicient to release top with respectthereto; Figure III is a after teeming; Figure V is a bottom plan 1931. Serial No. 554,219.

the hot top to sink with the ingot metal in the mold cavity. r

Where occurring throughout the figures of the drawing, reference numeral 1 represents an'ingot mold, and reference numeral 2 a hot top therefor.

According to my invention, I mount on support the hot top on the ingot'mold by means which disintegrate spontaneously unm der temperatures existing during and im- "3 mediately after teeming. It may not be said that this disintegration is slow at such temperatures. The supporting structure is, however, of such nature thatthe' disintegra- V tion is retarded. The supporting structure thus serves to. support the hot top in its mounted position for at least such time. as is required to fully teem the ingot. Shortly after teeming it spontaneously disintegrates I, to'release the hot top. '70

- As illustrated, the hot top supporting structure, designated generally by reference numeral 3, comprises primarily a torus or flat ring l; This fiat ring lis so proportioned ,4 for the size of ingot mold with which itjis" used, that the outer portion of its width 4a lies upon the upper edge, of theingot mold, and theinner portion 46 of its width extends horizontally inward of the mold cavity.

This flat ring 4 is'of a material which go burns or otherwise disintegrates under the temperatures encountered. If it is of light gauge steel, the disintegration is by fusion. If, as preferred, it is of fibre board, partial: lypreproofed by compression, orby the in-szs clusion of asbestos or other non-combustible material, the disintegration is by combus-. tion. In either instancethe disintegration is retarded in that it does not occur instantly uponsubjection of the ring 4 to molten metaleo at its teeming temperature.

In assembly, the ring 4 is placed upon the upper edge of the ingot mold 1, and a hot top 2 is placed upon the annular region 46 which extends mold cavity. Desirably, weight is brought to bear upon the ring portion 4a which lies upon the ingot mold, by placing suitable material, such as a ring of metal, on' this portion of the ring. I 1

horizontally inward of theta.

' The hot top 2 is drical contour, and has throughout its height an overall diameter slightly less than the diameter of the upper region in the mold cavity. When the ingot metal is teemed through the hot top and the ingot mold cavity is filled with the metal, the temperature to which the ring is subjected causes its disintegration within a relatively brief period of time. As the inner portionlb of the horizontal ring 4 disintegrates under the teeming temperature, assisted by the weight of the hot top 2, the hot top is released. Because of the further fact that its diameter is slightly less than the diameter of the ingot mold bore in its upper region, the hot top is thus free to float upon the metal in the mold cavity and to sink in the mold cavity with the metal as-it contracts.

As the freedom of thehot top to sink, when released by disintegration of ring portion 4?), is limited only by the contraction of the metal, and the contour of the mold cavity, there is little clamping action of the metal on the hot top. In-a relatively great percentage of teemings it is, therefore, possible to remove the hot top from the solidified ingot in condition for subsequent reuse. This is more particularly the case when multiple-piece hot tops are used.

It is highly desirable to attach to flat ring 4 two annuli, each of which performs a twofold function, and which together define the division between outer ring portion 4a and inner ring portion 4?). Of' the two annuli, annulus 5 is in position perpendicular to the under face of ring 4:. It is shown as attached to ring 4 by means of foot 511 onthe annulus and engaging the inner portion 4?) of the ring. 7

The annulus 5 serves to position the ring with respect to the ingot mold cavity, and also serves to prevent leakage ofmetal between the ring l and the upper edge of the ingot mold during and immediately after teeming. 1

Annulus 7 is attached to extend perpendicularly upward from ring 4 by means of an outwardly directed foot 7 a engaging the outer ring portion 4a. Annulus 7 serves to position the hot top properly with respect to the ingot mold cavity, and also prevents leakage of metal between the lower edge of hot top 2 and the upper face of flat ring 4. If multiple piece hot tops are used, the an nulus 7 avoids the necessity of tightly wiring the pieces together. v

The modified supporting structure of Figures V and VI is designated generally by reference numeral 8. The modification illustrated in these figures of the drawing resides only in the special contouring of the depending annulus 8a to fit the special contour of the mold cavity. The upwardly extending exteriorly of simple, cylinannulus 81) may be of simple contour to receive an annulus of similar contour.

It should be understood that the annuli of the supporting structure may, like the flat ring, be made either of slowly combustible material, as for example a partially fireproofedfibre board, or may be made of a material which will otherwise disintegrate under the temperature conditions, as for example thin gauge steel.

My manner of'supporting the hot top on the ingot mold is far more satisfactory than the expedient of suspending hot tops, to be released after the ingot metal has been teemed; or the expedient of inserting wedges or blocks beneath a ledge on the hot top, and removing the blocks orwedges to permit'the hot top to'sink after teeming.

According to-my invention, the sinking of the hot top after teeming is spontaneously effected during the propertime period after teeming; possibility of ingot metal leakage is eliminated; and further the hot top itself is not clamped bvthe metal as it solidifies so that in many instances the hot top remainsin condition suitable for subsequent reuse.

- It should be understood that throughout the specification and p by the terms ring and annulus tolimit these structural elements to a circularcontour. In accordance with the contour of the ingot mold and hot top they may be approximately rectangular, or of any other contour conforming to that of the ingot mold and hot top.

I claim as my invention: '1. Means for supporting a hot top on an ingot mold comprising a flat ring retardedly disintegratable at the temperatures existing during the teeming and solidification of an ingot,an annulus attached to the lower face of the ring intermediate its widthto extend downwardly in a generally perpendicular direction therefrom, said annulus being flexible to conform closely to the bore wall of an ingot mold cavity to form with the flat ring a seal therein, and an annulus extending upwardly from the oppositeface of the ring intermediate its width and constituting a positioning element surrounding the hot top and in co-operation with the fiat ring forming a seal at the lower edge of the hot top.

2. Means for supporting a hot top on an ingot mold comprising a flat ring retardedly disintegratable at the temperatures existing during the teeming and solidification of'an ingot, an annulus attached tothe lower face of the ring intermediate its width to extend downwardly in a generally perpendicular direction therefrom, said annulus being flexibleto conform closely to the bore wall of an lngot mold cavity to form with the fiat ring a seal therein, and an annulus extending upwardly from the opposite face of the ring constituting a positioning element disposed claims I do notintend to hand.

y EUGENE L. MESSLER.

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