Inductive heated bake oven

Abstract

Abstract An inductively heated bake oven for heating and warming cookware disposed in the oven comprising an outer housing fabricated from a magnetically non-permeable material and having a plurality of different sides joined together to form an enclosed space with one of th sides forming a door to provide access to the enclosed space. An inner housing is supported within the outer housing and may be fabricated from magnetically susceptible metal material or insulating material and have a plurality of different sides joined together to form an enclosed oven space. The inner housing is spaced from and supported within the sides of the outer housing with the side of the inner housing facing the door of the outer housing being open or accessible to provide access to the interior of the inner housing. A plurality of inductive heating coils preferably of planar, helically wound, pancake-shaped heating coil design are supported within the space intermediate the respective confronting sides of the inner and outer housings and arranged to maximize the inductive coupling to magnetically susceptible metal material either comprising the inner housing or supported within the inner housing if it is of insulating material. Electric circuit means is provided for electrically exciting the inductive heating coils at relatively high frequency of the order of 20 kilohertz to thereby magnetically induce the generation of heat in the inner housing or a metal based cookware disposed within the inner housing if it is of insulating nature. The outer housing may be formed of aluminum, copper or other highly conductive metal material which serves as an effective magnetic shield to confine the magnetic induction field to the space within the outer housing, and the inner housing may be formed of iron, stainless steel, titanium or the like or of an insulating material. If the inner housing is formed of a magnetic susceptible metal material, such as iron, stainless steel, insulation is placed in the space between the induction heating coil and the inner housing and the interior of the inner housing may be porcelainized or otherwise provided with an attractive, easy to clean interior surface similar to known oven interiors. If the inner housing is fabricated from insulating material, a pyroceramic insulating material, high temperature glass, etc. may be used. Preferably, individual excitation circuits are provided for each induction heating coil and the individual excitation circuits can be individually controlled to excite any desired number of coils. Preferably, a plurality of coils are provided one on each of five different sides of the oven so as to assure uniform and even heating of the interior of the oven. Temperature sensor units may be employed for sensing the actual temperature of the inner housing, or a metal base cookware disposed in the inner housing space. Cooling vents may be formed in either the inner or the outer housing or both to provide for removal of moisture in the oven space as well as to provide a flow of cooling air across the induction heating coils thereby maintaining their resistance at a low value and improving the overall efficiency of operation of the bake oven. If desired, self-cleaning of the oven can be provided for the inner housing member, if formed of a magnetically susceptible metal material, by Raising its temperature to sufficiently high value to achieve self-cleaning action. The inductive heating coils may be a helix wound from electrically insulated Litz wire or the like, or may be fabricated from a helix cut out of sheet metal.

Inventors

• 👤 P Peters

Bibliographic Details