Method and apparatus for continuously casting hollow rounds

Claim 3

A method as defined in claim 1 in which said plugs are acted on magnetically to detect eccentricity of said inside skin.

Claim 4

A method as defined in claim 1 in which a tubular starter bar is inserted in said mold from beneath preliminary to commencing a casting operation, and is disconnected from the partially solidified hollow-round by rotating it through a small arc.

Claim 5

Apparatus for continuously casting a hollow-round comprising a tubular water-cooled mold, a water-cooled lance suspended within said mold leaving an annular cavity therebetween, means for pouring molten metal into said cavity, whereby a partially solidified hollow-round having solidified outside and inside skins and a liquid core emerges from the bottom of said mold, which hollow-round solidifies throughout at a lower level, an extension on said lance below said mold, at least one water-cooled plug of magnetic material on said extension between the bottom of said mold and the level at which the hollow-round solidifies throughout, said plug being of a shape to ride against said inside skin, and magnetic means outside the hollow-round for maintaining said plug and said inside skin in a concentric relation with said outside skin.

Claim 6

Apparatus for continuously casting a hollow-round comprising a tubular water-cooled mold, a water-cooled lance suspended within said mold leaving an annular cavity therebetween, means for pouring molten metal into said cavity, whereby a partially solidified hollow-round having solidified outside and inside skins and a liquid core emerges from the bottom of said mold, which hollow-round solidifies throughout at a lower level, an extension on said lance below said mold, at least one water-cooled plug of magnetic material on said extension between the bottom of said mold and the level at which the hollow-round solidifies throughout, said plug being of a shape to ride against said inside skin, and magnetic means outside the hollow-round for maintaining said plug and said inside skin in a concentric relation with said outside skin.

Claim 7

Apparatus as defined in claim 4 in which said magnetic means includes opposed pairs of detecting magnets and positioning magnets opposite said plug, said detecting magnets responding to any shift in the position of said plug to change the attractive force exerted by said positioning magnets to restore said plug to a position concentric with said outside skin.

Claim 8

Apparatus as defined in claim 4 in which said extension is formed in sections, and including ball joints connecting said extension with said lance and said sections end-to-end, there being at least one plug on each section and corresponding magnetic means opposite each plug.

Claim 9

Apparatus as defined in claim 6 in which sAid extensions are tubular for conducting cooling water to said plugs, and including nozzles carried by said extensions for applying cooling water to the inside of the hollow-round below the mold.

Claim 10

Apparatus as defined in claim 4 including a tubular starter bar, a stool carried by said bar, means for inserting said starter bar into the bottom of said cavity, and means for rotating said starter bar through a small arc to disconnect it from said stool.

Claim 11

Apparatus as defined in claim 8 in which said starter bar has a plurality of L-shaped slots in its upper edge and said stool has bolts received in said slots for connecting the stool and starter bar.