Ferrite heating apparatus

• US 4,362,917 A
• Filed: 12/29/1980
• Issued: 12/07/1982
• Est. Priority Date: 12/29/1980
• Status: Expired due to Term

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Freedman, George, Bowen, Robert F.
• Primary Examiner(s): Envall, Jr., Roy N.
• Assistant Examiner(s): Leung, Philip H.
• Application Number:
  US06/220,531
• Time in Patent Office: 708 Days
• Field of Search: 219/10.55 E, 219/10.55 M, 219/10.55 F, 219/10.55 R, 436/241, 436/243, 436/107, 99/451, 99/DIG. 14
• US Class Current: 219/730
• CPC Class Codes: H05B 6/6494 for cooking

Abstract

A microwave heating appliance having a metallic member supporting a body comprising ferrite bonded to an outer surface of the metallic member with a grooved inner surface of the metallic member contacting a food body to be heated by thermal energy generated from microwave energy absorbed by the ferrite body and transferred through the metallic member to the food body. An additional metallic member forms a container for the food body, and adjacent peripheral areas of the two metallic members provide substantial microwave sealing between the two metallic members thereby substantially shielding the food body from the microwave energy when the appliance is placed in a microwave oven. Upper and lower surfaces of the interior of the appliance contain grooves to form corrugated surfaces which contact the food body and which permit juices produced by heating the food body to flow away from regions of contact between the corrugated surfaces and the food body.

Claims

1. A microwave heating appliance comprising:

a metallic container for holding a food body, said container having a substantially vertical lip, said container reflecting microwave energy incident from underneath;

a microwave transparent base for supporting said container;

a corrugated metallic cover pivotally movable with respect to said base, said cover being supported by said food body, said cover further having substantially vertical sides spaced from and substantially parallel to said lip of said container for forming a microwave choke to shield the interior of said container from microwave energy; and

a microwave energy absorber comprising ferrite material bonded to the upper surface of said cover for absorbing microwave energy at a substantial rate at temperatures below the Curie point region of said ferrite material while absorbing microwave energy at a substantially lower rate at temperatures above said Curie point region.

2. The microwave heating appliance of claim 1 wherein said Curie point region is above 500°

F.

3. The microwave heating appliance in accordance with claim 1 wherein said base has a plastic handle molded integrally therewith.

4. The method of heating a food body using microwave energy, comprising the steps of:

shielding said food body in an interior region defined by first and second corrugated pan-shaped metallic members having peripheral portions that are substantially parallel to each other, said first member being positioned above said second member, said second member being supported by a microwave transparent base, said first member being pivotally movable with respect to said base;

exposing a ferrite microwave energy absorber adhered to the upper surface of said first member to microwave energy to generate heat therein; and

conducting said heat through said first member to heat said food body positioned in said region.

5. A utensil for heating food in a microwave oven, comprising:

a metal container having substantially vertical sides;

a metal cover having a corrugated top;

said cover further having substantially vertical sides spaced from and substantially parallel to said sides of said container for forming a microwave choke to shield the interior of said container from microwave energy;

a microwave absorbing layer comprising ferrite bonded to the upper surface of said top;

a microwave transparent base supporting said container in an elevated position, said base having legs to allow air to flow underneath said container, said base having two grooved vertical columns; and

said cover having two microwave transparent posts extending horizontally from opposite sides therefrom, said posts respectively engaging said grooves for providing horizontal alignment between said container and said cover.