US2071906A - Ingot mold - Google Patents

Description

Fei-23, 1937. f R H STEVENS 2,071,906

INGOT MOLD Filed Feb. 7, 1935 2 sheets-sheet 1 31a/vento@ 251K. fava/z5'.

wwf-@6% Feb. 22'.,` 1937'.

R. H. STEVENS INGOT MOLD Filed Feb. 7. 1955 2 Sheets-Sheet 2 l grs/mantels v C., u

Patented Feb. 23, 1937 y INGOT MOLD Richard H. Stevens, Baltimore. Md., assignor to Bethlehem Steel Company, a corporation of Pennsylvania Application February '1, 1935, serial No. 5,348

4 claims. (o1. arf-139) This invention relates toimprovements in ingot molds and ingots and particularly toimprovements in the contour of the horizontal cross section of the vertically extended mold chamber and of the ingot formed therein. The improved contour of the chamber of my ingot mold is obtained through the use of a new type oi' corrugation therein.

Corrugated chamber walls in ingot molds arerv old, having been employed in casting for many years. of corrugations in the mold chamber is to increase the perimeter of the ingot cast therein, as the rate of cooling and solidification is to a great extent proportional to the surface area as' compared to the cross-sectional area ofthe ingot. Heretofore, however, in casting ingots of the slab type in molds having corrugations of uniform size and pitch, great diculty yhas been experienced, due to the ingot, during shrinkage, becoming caught at the corrugations. which caused a tendency on the part of the ingot to pull `on the flat side of the mold and causedthe mold to try to bulge. This produced a strain on the mold and invariably, after a number of castings, resulted in the cracking of the mold. The pulling also produced 4a strain on the' ingot, causing it also to crack.

It is the object of my present invention to pro- 430 vide an ingot mold with corrugated chamber walls which embody all the well known advantages thereof and at the same time permit freer lshrinkage of the ingot by allowing it to slide freely along the chamber walls without sticking or catching at the corrugations.

To accomplish this purpose I'provide the side walls of the ingot-forming chamber with a plurality of corrugations of varying pitch which decrease successively in pitch from the end portions of the side walls toward the center` thereof. These corrugations comprise an arcuate portion and a straight portion. Itvis through varying the length of the straight portions thatv the variance in the pitch of the corrugations is obtained, as the radii of the arcuate portions are uniform. I preferably provide the end walls of the chamber with corrugations which are of a uniform pitch. The general contour of the whole chamber is so designed as to produce an ingot having walls which are of a generally convex horizontal contour. In addition to the advantage before mentioned, an ingot cast in this mold, due to the convexity of its walls, rolls more quickly and with little or no ilshtailing.

The novel features of my invention will be As is well known in the art, the object' more fully understood from the following description and claims taken with the drawings, in which- Fig. 1 is a top plan view of an ingot mold constructed in accordance with my invention. 5 Fig. 2 is a side elevation of the ingot mold shown in Fig. 1.

Fig'. 3 is a bottom plan Vview of the ingot mold shown in Fig. 2.

Fig. 4 is a diagrammatic View of one quarter of 10 the top and bottom contours of the mold chamber, and of the contour of an ingot after cooling therein, the latter being indicated by the broken f line.

Figs. 1, 2 and 3 illustrate an ingot mold I 6 of 15 the big-end-down type and of a substantially rectangular or slab type contour. The molding or ingot forming chamber I1, as shown, is slightly concave on all four sides. The side walls I8 of the chamber II have corrugations I9, 2|), 2l, 20 22, 23, 2l, which vary in size and pitch from the end portions of the side walls I8 toward the center thereof, and the end walls 25 have corrugations 26, 21, 29, 29, all of which .will be more clearly observed by reference to Fig. 4. A11 25 of the corrugations of the side walls and end walls are connected by` outwardly arched portions 30. The end walls 25 are connected to the side walls I8 by outwardly arched corner salients 3|. l

The three center corrugations 20, I9 and 20 of the side walls are shown as being-of a regular arcuate contour, while all the remaining side wall corrugations comprisearcuate portions 32 and straight portions 33 (Fig. 4). The radii of 35 the arcuate portions 32 are of uniform length, while the straight portions 33 become successive- 1y smaller from the ends of the side walls I8 toward the center thereof. By thus varying the length of the straight portions 33 which thereby 40 varies the pitch of the individual corrugations I` obtain a mold which permits the cooling ingot to shrink freely and to contract horizontally in the direction oi' its major cross-section without sticking or catching at the corrugations as illustrated 45 in Fig. 4.

For purposes of illustration I shall now give the details of the various parts embodied in an ingot moldV of the big-end-down type having a mold chamber with a bottom dimension of 5()v 32 x 50 inches, a top dimension of 301/2 `x 481/2 inches, and a length of 84 inches. The thickness of the mold walls is substantially the same at any point in a common horizontal plane, the walls increasing uniformly in thickness from 55 the upper to the lower end of the mold. In a mold of the size illustrated the thickness of the walls at their thickest point is:

Side walls, 4 inches at top, 8 inches at bottom.

End walls. 3% inches at top, 'W2 inches at.

bottom.

The measurements of the corrugations, taken between the apexes of the outwardly-arched connecting portions 30. are as follows:

The center corrugation I9 is 31/2 inches long, and its arcuate portion is described by a radius of 2% inches.

The corrugations 2li are 3% inches long, and

their arcuate portions are described by radii of ci 6 inches.`

Ihe outwardly arched connecting portions 30 are all described by uniform radii of inch.

The outwardly arched corner portions 3i are described by radii of 1 inch.

The side walls I8 taper inwardly l inch from the center to the outer end thereof. y

The corrugations I9, 20, 2l, 22 and 23 of the side walls and corrugations 26, 21 and 2B of the end walls are all parallel from the upper to the lower end ofthe mold, while the corrugations 24 of the side wall and 29 of the end wall increase in size toward the lower end of the mold to compensate for and take up the increase in size of the chamber at the lower end. A

Molds constructed in accordance with my invention have proved most successful, having substantially if not entirely eliminated most of the defects occurring in molds of the slab type heretofore employed. In actual use they have produced a better ingot with fewer surface defects,

and the molds themselves have been found to last many times longer than those heretofore used. due to the elimination of strain on the walls thereof heretofore occurring-during the cooling of the ingot on account of the ingot catching or sticking at the corrugations.

Although I have4 described and illustrated my invention in considerable detail. I do not wish to be limited to the exact and specific details thereof, as shown and described, as it will be obvious that numerous variations thereof might be constructed without departing from the scope and spirit of my invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A metallic ingot mold with a chamber therein having side walls and end walls, said side walls comprising a plurality of corrugations which decrease successively in pitch from the ends of said side walls towards the center thereof, said corrugations comprising straight portions and arcuate portions.

2. A metallic ingot mold with a chamber therein having side walls and end walls, said side walls comprising a plurality of corrugations, certain of said corrugations comprising straight portions and arcuate portions, said straight portions decreasing in length from the end portions of said said walls towards the center thereof.

3. A metallic ingot mold with a chamber therein having side walls and end walls, said side walls comprising a plurality of corrugations. certain of said corrugations comprising straight portions and arcuate portions, said straight portions decreasing in length from the -end portions of said side walls towards the center thereof, all of said arcuate portions being described by equal radii.

4. An ingot mold having a chamber formed by side and end walls increasing in thickness from top to bottom, the inside faces of said side walls comprising a plurality of unequally spaced corrugations, certain of said corrugations being of arcuate formation and others of said corrugations being formed of arcuate and straight portions, all of said corrugations decreasing successively in pitch from the end portions of said walls towards the center thereof.

RICHARD STEVENS.

CERTIFICATE 0F CORRECTION.

Patent No. 2,071,906.

Februar-y 23, 193?.

RICHARD H. STEVENS.

It ie hereby certified that error appears in the printed specification of the abovefnumbered patent requiring correction as follows: Page 2, second column, line 2 8, claim 2, for the wo/rd "said" read side; and that the said Letters 'Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 6th day of April, li.v D. 1937.

ilSeal) Henry Van Arsciale y Acting Commissioner of Patents.

the upper to the lower end of the mold. In a mold of the size illustrated the thickness of the walls at their thickest point is:

Side walls, 4 inches at top, 8 inches at bottom.

End walls. 3% inches at top, 'W2 inches at.

bottom.

The measurements of the corrugations, taken between the apexes of the outwardly-arched connecting portions 30. are as follows:

The center corrugation I9 is 31/2 inches long, and its arcuate portion is described by a radius of 2% inches.

The corrugations 2li are 3% inches long, and

their arcuate portions are described by radii of ci 6 inches.`

Ihe outwardly arched connecting portions 30 are all described by uniform radii of inch.

The outwardly arched corner portions 3i are described by radii of 1 inch.

The side walls I8 taper inwardly l inch from the center to the outer end thereof. y

The corrugations I9, 20, 2l, 22 and 23 of the side walls and corrugations 26, 21 and 2B of the end walls are all parallel from the upper to the lower end ofthe mold, while the corrugations 24 of the side wall and 29 of the end wall increase in size toward the lower end of the mold to compensate for and take up the increase in size of the chamber at the lower end. A

Molds constructed in accordance with my invention have proved most successful, having substantially if not entirely eliminated most of the defects occurring in molds of the slab type heretofore employed. In actual use they have produced a better ingot with fewer surface defects,

and the molds themselves have been found to last many times longer than those heretofore used. due to the elimination of strain on the walls thereof heretofore occurring-during the cooling of the ingot on account of the ingot catching or sticking at the corrugations.

Although I have4 described and illustrated my invention in considerable detail. I do not wish to be limited to the exact and specific details thereof, as shown and described, as it will be obvious that numerous variations thereof might be constructed without departing from the scope and spirit of my invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A metallic ingot mold with a chamber therein having side walls and end walls, said side walls comprising a plurality of corrugations which decrease successively in pitch from the ends of said side walls towards the center thereof, said corrugations comprising straight portions and arcuate portions.

2. A metallic ingot mold with a chamber therein having side walls and end walls, said side walls comprising a plurality of corrugations, certain of said corrugations comprising straight portions and arcuate portions, said straight portions decreasing in length from the end portions of said said walls towards the center thereof.

3. A metallic ingot mold with a chamber therein having side walls and end walls, said side walls comprising a plurality of corrugations. certain of said corrugations comprising straight portions and arcuate portions, said straight portions decreasing in length from the -end portions of said side walls towards the center thereof, all of said arcuate portions being described by equal radii.

4. An ingot mold having a chamber formed by side and end walls increasing in thickness from top to bottom, the inside faces of said side walls comprising a plurality of unequally spaced corrugations, certain of said corrugations being of arcuate formation and others of said corrugations being formed of arcuate and straight portions, all of said corrugations decreasing successively in pitch from the end portions of said walls towards the center thereof.

RICHARD STEVENS.

CERTIFICATE 0F CORRECTION.

Patent No. 2,071,906.

Februar-y 23, 193?.

RICHARD H. STEVENS.

It ie hereby certified that error appears in the printed specification of the abovefnumbered patent requiring correction as follows: Page 2, second column, line 2 8, claim 2, for the wo/rd "said" read side; and that the said Letters 'Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 6th day of April, li.v D. 1937.

ilSeal) Henry Van Arsciale y Acting Commissioner of Patents.

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