Patent ID: 7337745

Claim:
An electrode comprising: a base metal formed of a cast metal; a heater embedded in the base metal and arranged on a plane; and a pair of core metal plates embedded in the base metal and arranged substantially parallel to the plane and adjacent to the heater, the core metal plates being arranged above and below the heater, respectively; wherein the heater and the core metal plates are cast in the base metal such that the core metal plates are entirely surrounded by the base metal and are entirely in metal-to-metal contact with the base metal; wherein a material forming the core metal plates has a rigidity higher than that of a material forming the base metal; and each of the core metal plates has a plurality of through holes, which are filled with the base metal so that the base metal above the respective core metal plates and the base metal below the respective core metal plates are bound together via the base metal filled in the through holes.