Method of manufacturing composite metallic rolls

Claim 1

IN A METHOD OF MANUFACTURING COMPOSITE METALLIC ROLLS HAVING WEAR-RESISTANT EXTERNAL SURFACES, INVOLVING (A) MOUNTING AN APERTURED METALLIC CORE ROLL WITHIN A METALLIC FORMING TUBE HAVING A DIAMETER GREATER THAN THAT OF SAID ROLL AND DEFINING AN ANNULAR REGION THEREBETWEEN; (B) INSERTING A METALLIC COMPOSITION, MELTING AT A TEMPERATURE OF EXCESS OF 1000*F. AND LESS THAN THE MELTING POINTS OF SAID ROLL AND SAID TUBE, WITHIN THE SAID ROLL; (C) SEALING THE ENDS OF SAID ROLL AND OF SAID ANNULAR REGION; (D) HEATING THE RESULTING COMPOSITE ASSEMBLY AT TEMPERATURES SUFFICIENT TO MELT SAID METALLIC COMPOSITION; (E) ROTATING THE COMPOSITE ASSEMBLY TO CENTRIFUGALLY DISTRIBUTE THE MOLTEN COMPOSITION THROUGHOUT SAID ANNULAR REGION; AND (F) COOLING THE COMPOSITE ASSEMBLY DURING ROTATION THEREOF TO THEREBY SOLIDIFY THE MOLTEN METAL AND FORM A WEAR-RESISTANT METALLIC COATING ON SAID ROLL; THE IMPROVEMENT COMPRISING (A) MOUNTING THE APERTURED CORE ROLL WITHIN THE FORMING TUBE WITH A FIRST END OF THE ROLL IN SUBSTANTIALLY CO-PLANAR ABUTTING RELATION WITH A FIRST END OF THE TUBE, AND THE OPPOSITE END OF THE ROLL DISPLACED INWARDLY OF THE OPPOSITE END OF THE TUBE BY A DISTANCE AT LEAST EQUAL TO THE DEGREE OF THERMAL EXPANSION OF SAID ROLL DURING SAID HEATING STEP; (B) MOUNTING END PLATES AT THE OPPOSITE ENDS OF THE COMPOSITE ASSEMBLY, THE FIRST END PLATE BEING MOUNTED IN ABUTTING RELATION WITH SAID FIRST END OF THE ROLL, AND THE SECOND END PLATE BEING MOUNTED IN ABUTTING RELATION WITH SAID OPPOSITE END OF THE TUBE; (C) WELDING SAID FIRST END OF SAID ROLL TO THE ABUTTING FIRST END WALLS OF SAID TUBE AND TO THE ABUTTING WALLS OF SAID FIRST END PLATE TO SEAL THE FIRST END OF THE COMPOSITE ASSEMBLY; AND (D) WELDING SAID SECOND END PLATE TO THE ABUTTING FIRST END WALLS OF SAID TUBE AND TO THE ABUTTING WALLS OF SAID FIRST END PLATE TO SEAL THE FIRST END OF THE COMPOSITE ASSEMBLY; AND (D) WELDING SAID SECOND END PLATE TO THE ABUTTING OPPOSITE END WALLS OF SAID TUBE TO SEAL THE OPPOSITE END OF THE COMPOSITE ASSEMBLY AND THEREBY PROVIDE AN EXPANSION JOINT PERMITTING THERMAL EXPANSION OF SAID ROL WITHIN SAID TUBE DURING SAID HEATING STEP.