Electromagnetic induction heating apparatus including a magnetic flux diverting assembly

Claim 1

An electromagnetic induction heating apparatus for heating a strip which has a predetermined width, as measured between opposed strip edges, and which is moved at a predetermined speed in a predetermined direction, said apparatus comprising: (a) a pair of electromagnetic assemblies positioned in spaced relationship from each other so to define a passageway along which said strip is adapted to be moved in said predetermined direction, said electromagnetic assemblies forming an alternating magnetic field, each of said assemblies comprising a plurality of electromagnets, each of said electromagents having a width in a direction transverse to said predetermined direction which is less than the width of said strip; (b) means for adjusting magnetic flux generated by said electromagnetic assemblies, said adjusting means comprising a plurality of flux modifiers, each of said electromagnets having opposed ends between which said electromagnet width is defined, said flux modifiers being slidably positioned on opposite ends of said electromagnets, said flux modifiers being mounted adjustably with respect to the width of said strip, said flux modifiers thereby comprising means for moving a portion of the magnetic flux generated by said electromagnetic assemblies towards said opposed edges of said strip; and (c) means for diverting said magnetic flux which traverses an area adjacent to said strip edges, said diverting means comprising a laminated ferromagnetic sheet which is positioned adjacent said opposed strip edges, said magnetic flux diverting means comprising a plurality of magnetic flux diverting members which are independent from said electromagnetic assemblies and said magnetic flux adjusting means, each of said magnetic flux diverting members having one surface which faces a top surface of said strip and one surface facing a bottom surface of said strip, said magnetic flux diverting members extending in a direction which intersect said predetermined direction along which said strip is adapted to be moved, said magnetic flux diverting members thereby comprising means for diverting a portion of said magnetic flux in order to uniformly heat said strip across the width of said strip.