US1117181A - Ingot-mold and sink-head therefor. - Google Patents

Description

E. GATHMANN-A INGOT MOLD AND SINK HEAD THEREFOR.

APPLICATION FILED AUG. 11, 1914 Patented N0v."17, 1914.

nmrr. 'GATHMANN, or BALTIMORE, MARYLAND.

INGOT-MOLID AND SINK-HEAD THEREFOR.

Specification of Letters Patent.

Application filed August 11, 1914. Serial No. 856,243.

To all whom it may concern:

Be it known that I, EMIL GATHMANN, a citizen of the United States, residing in Baltimore city, State of Maryland, have invented certain new and useful Improvements in Ingot-Molds and' Sink-Heads Therefor, of which the following is a specification.

This invention relates particularly to moldsfor casting steel ingots and especially to the sink heads or feeders for such molds, but my improvements may be employed in connection with molds for other kinds of castings.

In several U.'S. Letters Patent heretofore granted to me I have shown molds for easting steel ingots in which provision is made for conserving the heat of the molten metal at its upper portion and for promoting the cooling of the lower portion of the ingot or casting. I have demonstrated that in this class of molds improved results can be obtained by the use of a feeder or sink head whereby the metal of the casting may be better maintained in a molten condition for a considerable period of time at its upper end and thus provide a sufficient supply of liquid metal for feeding the lower portion of the casting to fill the pipe therein until the casting is substantially solid.

In carrying out my invention I preferably form the main body ofthe mold with the walls of the lower portionconstructed or equipped to promote the cooling of the ingot or casting, and I also preferably make the walls of the upper portion of the mold somewhat thinner than the walls of the lower portion thereof, causing said mold Walls to progressively decrease in thickness from bottom to top. With a mold thus constructed I employ a sink head or feeder of the mold walls that the line of rapid cooling of the ingot extends upwardly to approximately 75% of the cavity content of the mold, or in other words, 75% of the vertical mass of the ingot when in a liquid or molten condition, while the upper or remaining part of the mold walls is constructed to conserve the heat of the ingot. when the'mold Walls are constructed in this way the casting of a sound ingot is promoted by placing in the upper end of the mold cavity a feeder or sink head of insulating material, such as fire clay, which not only acts as a feeder for the mold, but also assists in conserving the heat of the ingot at its upper end.

Any substantial variation from the measurements above specified do not give the best results and it is also desirable that the cool molds constructed in the manner described,

but also with molds of other construction. Sink heads are usually although not always made of fire clay cast in one piece, but experience has demonstrated that it is practically impossible, even with great care and large expense, to mold a sink head of fire clay or similar material which will make a close fit with the mold walls. Furthermore sink heads as heretofore constructed have been very short lived, lasting generally for only one heat or the casting of one ingot.

I have demonstrated that sink heads may be cheaply made in such manner as to make a tight fit -with the mold cavity by making them in sections which, when placed in the mold, are expanded and thus made to fit tightly the mold cavity. Wedges are pref-- erably used for this purpose and the spaces between the ends of the feeder sections are filled with suitable plastic material. I have found that the sink heads should be divided on neutral shrinkage lines passing through the longitudinal central axis of the mold as in this way the breaking of the feeder by interlocking finson the ingot during the shrinkage of the latteris prevented.

' In the accompanying drawings, shows a ertical central section through an ingot mold equipped with a feeder and constructed in accordance with my invention.

Patented Nov. 17, 1914. I

I have found that sorbing portion a of the mold preferably extends from the bottom thereof to the bottom of the neck portion of the mold as indicated by the dotted line a9w. The walls a of the neck are made considerably thinner and thus less heat absorptive so that the heat of the ingot within the neck is conserved, while the heat of the ingot below the neck is rapidly absorbed. The relative proportion of the thick and thin walls are such that the line of rapid cooling of the ingot extends to approximately 7 5% of the cavity content of the mold, or, in other words, 75% of the vertical mass of the ingot when in a molten or liquid state. These dimensions are of importance when a feeder or sink head is used as T have practically demonstrated; any material departure from them will not produce the best results as the cooling of the ingot from top to bottom must be progressive and the conservation of the heat musthave such relation to the cooling of the ingot as to cause the pipe to be filled progressively at the proper rate. The mold is provided with devices a a of well known construction for engaging the stripping or lifting mechanism of any well known kind. The mold thus constructed is especially adapted for use in connection with a sink head or feeder of insulating material, such as fire clay, which not only serves to feed the molten metal, but also to provide a lining of insulating material in the neck of the mold for the purposes above explained. It is quite necessary that when the feeder is placed within the mold and secured thereto it should make a tight fit with the walls of the mold cavity. If it is loose in the mold, the molten metal as it rises will lift the feeder and will also find its way between the periphery of the feeder and the walls of the mold. I have found it very difficult and practically impossible to make the feeder in one piece and secure a tight fit, because, when the fire clay is cast to give the desired form to the feeder it shrinks in an irregular way, is apt to break and can only be fitted to the mold at large expense. 1 have obviated these dificulties by casting the feeder in sections and providing devices which shall spread them in the mold and effect a tight connection therewith. T have also found that it is not desirable to divide the feeder at the corners, because, inasmuch as the ingot when cooling shrinks in opposite ,directions from its sides away from the mold walls toward the vertical central axis of the mold, a strain is put on the feeder by the fins formed in the joints at the corners between the sections. Instead of dividing the feeder at the corners l divide it on the neutral lines of shrinkage between the corners. Preferably the sink head is divided into four parts as shown in the drawings, each part b, b b 71 being molded separately. The feeder as a whole has a flange 6 adapted to rest on the top of the mold as shown. 75 The walls of the mold cavity at its upper end are preferably made smooth and straight to receive the feeder and insure a tight fit. The feeder sections are placed in position in the mold cavity and secured inplace by 8t suitable devices, preferably by wedges D which operate to spread the sections, hold them securely in place and make a tight fit with the mold wall. After this the cracks at the junctions of the sections are filled with plastic material 6, such as fire clay or other suitable material, and a wash 6' of fire clay and graphite may be applied to the inner walls of the feeder, as indicated in Figs. 3 and 4:. When the feeder is thus applied it remains as a permanent part of the mold and can be used-as long as the mold lasts, the cracks being from time to time filled and a new wash of clay and graphite applied when required.

The mold may be either top or bottom cast, 2'. 6., the molten metal may be poured either at the top or at the bottom by well known methods. The cavity of the mold shown is wider at bottom than at top, but let my improvements may be embodied in molds of other kinds.

I claim as my invention:

1. The combination with an ingot mold having its lower part for approximately 75% of the cavity content of the mold made thick and highly absorptive and its upper portion or neck relatively thin and adapted to conserve the heat of the upper portion of theingot, and a sink head oflll) insulating material fitted in the neck of the mold and serving to increase the heat conserving properties of the neck thereof.

2. A sink head or feeder for metallic molds adapted to fit the cavity of the mold Ht neck made of refractory material and divided into four sections on neutral lines of ingot shrinkage between the corners, sub stantially as described.

8. The combination with a mold, of a sink headmade in sections and means for y forcing the sections sidewise into contact with the walls of the mold cavity.

'4. The combination with a mold, of a sink head divided on neutral lines between its corners into sections, and means for forcing the sections sidewise into contact with l the walls of the mold cavity.

5. The combination with amold, of a sink head divided on neutral lines between its corners and wedges interposed between the sections for spreading them and holding them in close contact with the mold walls.

6. The combination with a mold, of a sink head divided on neutral lines between its corners, means for forcin the sections into contact with the, walls 0 the mold cavity,

and means for filling the cracks or openings 10 EMIL GATHMANN Witnesses MAMIE MEWSHAW, CHARLES F. EARLY.

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