Patent ID: 7110430

Claim:
An induction furnace for melting material, the furnace comprising: an electrically non-conductive crucible defining a melting cavity; an electrically conductive member disposed adjacent the crucible in a fixed relation with respect to the crucible; an induction member for creating an electromagnetic field to inductively heat material within the melting cavity and to inductively heat the conductive member; each of the conductive member and the material within the melting cavity absorbing energy from the electromagnetic field transferred by direct inductive coupling with the induction member whereby the conductive member and material together absorb a combined energy from the electromagnetic field transferred by said direct inductive coupling; the crucible, conductive member and induction member being positioned with respect to each other so that inductive heating via the induction member occurs initially within the conductive member and occurs in the material within the melting cavity when the conductive member has transferred sufficient heat to the material to make the material susceptible to inductive heating so that at a certain time during inductive heating the conductive member absorbs no more than thirty percent of the combined energy absorbed by the conductive member and material transferred by said direct inductive coupling.