US1620011A - Method of making ingot molds - Google Patents

Description

192 March 8 7 G. A. DoRNlN METHOD 0F MAKING INGOT HOLDS original Fild April 1e, 1925 2 Sheets-Sheet l Barnim 1,620,0114 G. A. DORNIN METHOD oF MAKING INGOT uoLDs March 8 1927.

original Filed April 16. 1925 2 Sheng-sneek 2 @www Patented Mar. 8,. 1927.

UNITED STATES PATENT oFFlcE.

GEoEGE A. noENIN, or BALTIMORE, IIAE'TEANII''Assrefafon ro THE GA'rn'MANN' o ENGINEERING COMPANY, or BALTIMORE, MARYLAND.

METHOD F MAKING INGOT HOLDS.

Original application illed April 16, 1925, Serial No. 23,586. Divided and this application tiled Septemb 4, 1925. Serial No. 54,519. i

'This invention relates to metal molds of a kind commonly used for casting steel ingots and particularly to molds of this class in which the lowerV part of the mold Walls are made thicker than the uppenpart thereof and in which the mold cavity is made ofv larger diameter at the top of the mold than at the bottom thereof. This is a characteristic of the Gathmann molds now in general use.

In the casting of metal mblds of the kind just referred to. it has been found that better results are obtained when the sand molds in which the metal molds are cast, are bottom poured, withoutv a cope or cover, the

molten metal being caused to rise in the sand mold until the desired size-and shape is 0btained. This method of casting ingot molds is so greatly superior to other methods that it has been generally adopted. It has, however, one defect. The upper surface of the casting when formed is quite rough and uneven and in such condition the mold is not suitable for use inasmuch as the top surface of the casting which constitutes the bottom of the ingot mold when in use will not rest properly on a stool or support. Therefore the common practice heretofore has been to remove this rough surface by suitable tools or machine driven implements. This operation however, adds considerably to the cost of the mold and such cost naturally goes into the cost of the ingot and consequently into the cost of the steel. f I have found a most simple. cheap and efficient way of removingr these objections and I do this during the process of casting the mold so that the subsequent operation of machining the mold bottom is rendered unnecessary.

The preferred wayof lcarrying out my invention is illustrated in the accompanying drawings in which- Figure 1 is a view partly in ,side elevation and partly in vertical section of an ingot mold made by my improvements and showing how it is supported. Figure 2 is atop plan -view thereof.

Figure-,3 shows a vertical section of the lower part of the mold showing how it enters thestool or support. the section being taken on the line B--B of Figure 2.

Figure 4 shows a vertical sectiony of the lower portion of the mold and the stool.

Figure 5 shows a vertical section of a sand mold with my improvements applied and shows how the metal molds cast therein.

Figune 6 is a top plan view of a sand mold.

In Figure 1 a mold of the Gathmann type is indicated at A. B indicates a stool and C a truck on which the 'stool is supported.

In eneral the mold A is of usual construction but it differs from oth-ers in the formation of its bottom wall.

It will be observed that the central part a of the bottom extendsbelowl the` marginal portions b thereof-and that while the under side ofthe central portion is rough and uneven, the marginal portions are smooth and even so that the mold is held in a truly vertical position when placed on its stool. These smooth marginal portions are preferably formed on two sides only of the mold, but they may extend continuously or at intervals entirely around the mold. These smooth marginal portions are produced during the process of casting.

Figures 5 and 6 illustrate how the smooth and even marginal portions are formed in' the mold during the casting operation.

A sandl mold of well known construction is illustrated, at D,- the sand parts being shown at d and the flask or frame parts being shown at d. The ingot mold cast in the mold is shown at A. The mold is bottom poured being supplied with molten metal by a feeding device E of well known construction. spects to those .heretofore used but I provide means at the top of the sand moldfor producing the smooth and even"marginal por tions of the ingot mold before referred to. The simplest and best way now known to me for performing this function is to support on the top of the sand mold two heavy metal The sand mold is similar in all rebars F having smooth under sides. As the molten met-al rises in the san'd mold, it comes in contact with these bars and is chilled thereby. After the metal reaches the level of the chill bars. it continues to rise between these bars until it rises a suiiicient distance above their bottom, or high enough to slightly overow the sand mold. at which time the kish or impurities which accumulate in the metal during pouring can be scraped or raked oi sidewise between the chill bars. This operation of raking off kish is a necessary part of forming ingot molds in open top sand molds when said ngot molds are poured from direct metal. In this way smooth, even marginal parts are formed on opposite sides of the middle portion of the bottomof the mold which extends between the bars as indicated in Figure 5. When the metal mold is completed, the sand mold is withdrawn and in use the metal mold is reversed and supported in the manner indicated in Figure 1. v

It will be observed that the sand mold is so constructed and its core is so formed that a metal ingot mold of the big-end-up type is produced with an opening 1n its bottom to receive a plug P which is generally emloyed in this class of molds to close the ottom of the mold and to provide a strip-E ping devioe. i

This application is a division of my application for Patent, Serial No. 23,586, filed Apr. 16, 1925, in which claims are made to the novel features of the mold herein shown and described.

I claim as my invention:

The method hereinbefore described of casting an ing'ot mold, which Consists in bottom pouring a sand mold to cast the ingot mold bottom-side up, forming smooth, hard ledges on the top of the casting when the molten metal has risen to the upper portion of the sand mold and allowing a middle or central portion of the molten metal to rise above said smooth ledges to thus separate impurities from that part of the casting where then ledges are formed.

In testimony whereof, I have hereunto subscribed my name.`

' GEORGE A. DORNIN.

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