Patent ID: 7525073

Claim:
An inductor for electric induction heating of an electrically conductive workpiece, the inductor comprising: at least one pair of opposing coils formed from a first and second coil, the electrically conductive workpiece placed between the pair of coils, the pair of coils oriented across the cross section of the workpiece, each of the first and second coils comprising a plurality of coil sections traversing an opposing surface of the workpiece, the plurality of coil sections comprising at least two central sections traversing the workpiece, each of the at least two central sections joined together at adjacent ends by an edge section, the opposing plurality of coil sections of the first and second coils equidistant from each other; at least one flux concentrator at least partially surrounding at least one of the coil sections, the at least one flux concentrator comprising a “U” shaped concentrator located around at least one of the edge sections; an operator for moving the at least one flux concentrator in a direction perpendicular to the surface of the workpiece; and at least one ac power supply suitably connected to the first and second coils of the inductor to supply ac power to the inductor to inductively heat the workpiece to a cross sectional temperature profile.