US1148801A - Apparatus for multiple-layer steel-casting. - Google Patents

Description

, A. ROJEKOFF.

' APPARATUS FOR MULTIPLE LAYER STEEL CASTING.

APPLICATION FILED SEPT-18,1912.

1,148,801 Patented Aug. 3, 1915.

- NTOR MM 0f/%- ATTORNEY PM CCL, WASHINGTDN D C ALEXANDER 'ROJEKOFF, or ZBIEJI'IZA, RUSSIA.

APPARATUS FOR MULTIPLE-LAYER STEEL CA-STIN'G.

Application filed. September 18, 1912.

To all whom it may concern Be it known that I, ALEXANDER RoJEKoFr, a subject of the Emperor of Russia, and a resident of Biejitza, Russia, (my post-office address being Briansky Works, Biejitza,) have invented certain new and useful Im provements in Apparatus for- Multiple- Layer Steel-Casting, of which the following is a specification. I

My invention relates to steel castings which are composed of a plurality of different layers of steel, 7;. 6., steel of various chemical composition.

The object of my invention is to provide means for producing perfect castings of this kind, to wit, castings which are free of blow holes, cracks, or other defects. For making castings of this kind, molds are used, which are divided by partitions into two or more compartments. In order to make such castings successfully the fact is to be taken into consideration that fluid steel, when it has been poured into the mold contracts upon cooling, while the partitions, as they come in contact with the hot molten mass, expand. Consequently, if the dimensions of the partitions exactly correspond to the proportions of the mold, a rupture of the mold must necessarily occur at the place where the partitions come in contact with the inner walls of the mold. As a result thereof, the partitions, which form a part of the casting will, owing to their expansion, project beyond the contour of the casting, whereby the latter, of course, is spoiled.

In the accompanying drawing, illustrating my new invention, Figure 1 is a plan view of one form of mold with a partition placed therein according to my invention. Fig. 2 is a similar view of another form of a mold, and Fig. 3 shows a further modification.

As shown in Fig. 1, the partition N is less in width than the distance between two of the inner walls of the mold, between which walls the partition is placed. Not only must the partition not come in contact with the inner walls of the mold when placed therein, but on no condition must the partition enter any recesses in said inner walls to be held therein. Furthermore, the partition N must have a certain thickness, which should be determined by the temperature of the molten steel, which is poured into the mold and also by the cross section of the Specification of Letters Patent.

clearly shown in the drawing.

Patented Aug. 3, 1915.

Serial No. 720,953.

casting to be produced, for, unless the partition is not of the proper thickness, the fluid steel contained in one compartment of the mold will either melt the partition and mingle with the molten mass contained in the adjacent compartment, or, if the thickness of the partition be too great, the partition will not, as it should, properly combine with the molten steel, in which case, of course, the casting will not form a uniformly fused mass. In order to obtain a perfect casting, the thicknessvof the partition should be no less than 1% and no more than 3.8% of the cross-section of the entire casting.

That the partition completely combine with the molten steel in both compartments, but not come in contact with the inner walls of the mold when it is placed therein is a matter of great importance in the production of such castings, which are composed of Various layers of steel having different compositions, for if the partition is fitted exactly to the proportions of the mold, it will, on becoming heated by the molten mass of steel, expand and project on both sides of the finished casting. Moreover, it is a fact that the molten mass cools faster on the outside than on the inside, and by the projecting edges of the partition, further heat would be consumed and an imperfect casting would be obtained. With my object in view to obtaining perfect castings, I therefore consider it necessary not only to arrange the partition as shown in Fig. 1, leaving a space between its edges and the inner wall of the mold, but even to reduce the thickness of the partition along said edges as With the partition thus arranged and shaped it can freely expand without any danger of projecting beyond the contour of the finished casting and owing to the reduced thickness along said edges, the partition will uniformly combine with the molten mass in both compartments, notwithstanding the fact that the walls of the mold have a great cooling effect on the hot molt-en mass. The molten steel for one of the compartments of the mold is poured in at S and enters the mold from the bottom. The molten steel for the other compartment of the mold shown in Fig. 1 is poured in at S.

In Fig. 2 a mold is shown which is used for producing a casting composed of concentric layers. In a mold of this kind the no partitions N and N must not form anunbroken body, but the inner edges must, as shown in said figure, overlap each other, leaving a space between them, so that the partitions on coming in contact with the hot fluid metal can expand, otherwise cracks Would occur in the casting, making the same defective.

As shown in Fig. 3,,the partition is provided with a plurality of iron or steel pins, or hooks, 70, which pass through the partition. Such a partition is used in the production of castings which shall not be subjected to further treatment, such as hammer ing, rolling, &c., and, therefore, are made more solid. Theluse of such pins or hooks, therefore, is considered especially advantageous inthe production of castings having a special shape, :such, for instance, as shown in said Fig. 3.

The partitions to be held in place in the molds may be suspended from rods placed on the molds, or they may be supported by any other suitable overhead device, such as Copies of this patent-may be obtained for will readily suggest itself to one skilled in the art. i

I claim as my invention:

1. In combination with a mold for producing metal castings, comprising layers of various composition of metal, any number of metal partitions dividing the mold into compartments, said partitions having a thickness of no more than 3.8% and no less than 1% of the diameter of the entire casting. T

2. In combination with a mold for producing metal castings, comprising layers of various composition, a metal partition of less Width than the distance between the two opposed walls of the mold and provided with'reduced edges. In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses. i ALEXANDER ROJEKOFF. Witnesses SYLVIA TATLIN, ALEXA DER TSCHEXALOFF.

five cents each, by addressing the Commissioner of Patents,

Washington, D. G.

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