General Electric Company

Royce W Hunt

Raymond L Dills

Louis H Fitzmayer

John C Reiche

W S Ng

A solid disk surface unit mounted in a glass or ceramic support surface, comprising a plate member of cast material with one or more resistive heating elements mounted to the underside thereof and a thermally conductive cover member enclosing the underside of the plate member with its peripheral edge in close thermal contact with the plate member near its periphery, is provided with a thermally responsive switching device thermally coupled to the cover member and adapted to respond to the surface temperature of the cover member at a point relatively remote from its peripheral edge. The switching device is operative to remove power from the resistive heating elements of the surface unit when the sensed cover member temperature exceeds a predetermined threshold temperature, thereby protecting the glass support surface from damage due to thermal stresses resulting from hot spots occurring near the periphery of the surface of the plate member.

Thermal protection arrangement for solid disk glass cooktop

A microwave oven with a dual feed excitation system comprising in one form of the invention a rotating antenna supported from the top cavity wall and a slotted radiating chamber supported from the bottom cavity wall. The antenna and radiating chamber are coupled to the magnetron output probe by a waveguide having a central section for receiving energy from the magnetron probe; a first section for coupling energy from the central section to the antenna and a second section for coupling energy from the central section to the radiating chamber. The fractional apportionment of the total energy from the magnetron between antenna and radiating chamber is a function of the impedance presented by each. The impedance of the antenna varies as the antenna rotates. The impedance of the chamber is particularly sensitive to food load parameters such as dielectric constant, which changes as the food cooks. Thus, the fractional distribution of energy between antenna and chamber varies during the cooking process, resulting in improved cooking performance.

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Jeffersonville, IN, United States of America

Royce W Hunt