US 4,063,068 AGranted

Food heating and cooking receptacle

AssigneeMinnesota Mining and Manufacturing Company

InventorsDavid G. Johnson, Robert D. Thorson

Life of this patent

Estimating the term…

Loading patent…

Abstract

A portable food serving receptacle capable of heating chilled or frozen food to cooking or serving temperatures and automatically maintaining food at serving temperature. The receptacle consists of thin metallic walls and utilizes a flexible heating element of electrical and thermal insulating material. The heating element is adhered to the metallic walls of an inner dish of the receptacle. The insulating material of the heating element forms a laminated structure in which the electrical resistor is embedded. The walls of the receptacle have a substantially higher thermal conductivity than the laminate. The rate of heat flow from the heating element to the interface of the food and metallic walls of the receptacle is controlled by the thermal insulating characteristics of the laminate so that gradients of heat entering any given point of the food are substantially equal and are maintained at temperature levels below the scorching temperature of the food.

Claims1

Dependent claims

A food heating receptacle for heating food comprising:

a. a base member;
b. a metallic dish having a thickness of about 0.09 cm suspended in said base member and sealed at its outer edges with said base member, the bottom edge of the dish being in spaced relation to the bottom of said base member;
c. a heating element secured to the bottom of said dish, the element consisting of a laminate of polymeric material and first and second electrical conductors interwoven in said laminate to form electrical conductors spaced from each other within said laminate to provide electrical insulation, the laminate forming thermal insulation means to control the rate of heat flow generated by said conductors through said laminate and dish to the interface of the dish and food so that the amount of heat transferred to the food at any point along the interface of the food and dish maintain said food in the range of 91.1.degree. C and 106.6.degree. C;
d. a first thermostat connected to said first conductor and disposed on said dish to energize and de-energize said first conductor within predetermined temperature levels for heating and cooking food;
e. a second thermostat connected to a second conductor and disposed on said dish to energize and de-energize said second conductor within predetermined temperature levels for maintaining the food at serving temperatures and for de-energizing said conductors in event said temperature levels exceed predetermined temperature levels for the operation of said receptacle;
and
f. a thermal cover disposed over said dish and base member.

4 more elements

Dependencies are inferred from the claim text.