Induction heating apparatus for drink can

A drink can induction heating apparatus for induction-heating a drink can in a vending machine, said drink can having a bottomed tubular can body with a drinking liquid contained therein, said apparatus comprising:

• a plurality of ferrite cores each having a plurality of projected portions arranged along a longitudinal axis of the drink can and confronting a circumferential wall of the drink can at portions thereof other than at axial ends thereof, said plurality of ferrite cores arranged in a circumferential direction of the drink can so that each of said projected portions is oriented toward the longitudinal axis of the drink can in a non-contact manner when the drink can is temporally held at a given position in the vending machine, each of said ferrite cores further having one or more recesses formed between the projected portions;
• a saddle-shaped heating coil having a central open portion and received in the recesses of said ferrite cores with said central open portion receiving therethrough at least one of said projected portions of each of said ferrite cores, said heating coil having a coil surface which covers a portion of the circumferential wall of said drink can in a non-contact manner;
• and
• an inverter including a resonance circuit for producing AC power at a given frequency for feeding to said heating coil, said given frequency being no greater than a value where a current penetration depth becomes about five times a thickness of the circumferential wall of the drink can in case the drink can is formed of a non-magnetic material, said resonance circuit including a resonance capacitor having a given capacitance and said heating coil which are connected electrically in one of series and parallel,
• wherein, when the AC power is fed to said heating coil, one or more magnetic circuits are formed between said projected portions of each of said ferrite cores and the circumferential wall of the drink can confronting said projected portions.