초록 ▼

A heat retention device is disclosed in the form of a heating pad which includes an electrically resistive coil contained within a volume. The coil terminates at an electric coupler which is external of the volume. A heat retention mass is contained within the volume in thermal conductivity with the

A heat retention device is disclosed in the form of a heating pad which includes an electrically resistive coil contained within a volume. The coil terminates at an electric coupler which is external of the volume. A heat retention mass is contained within the volume in thermal conductivity with the resistive element.

대표청구항 ▼

[ What is claimed is:] [1.]1. A method for maintaining the warmth of food, said method comprising:(a) heating a warmer, the warmer comprising:(i) a plastic member defining an interior volume;(ii) a phase change material for storage of latent heat positioned within the interior volume of said plastic

[ What is claimed is:] [1.]1. A method for maintaining the warmth of food, said method comprising:(a) heating a warmer, the warmer comprising:(i) a plastic member defining an interior volume;(ii) a phase change material for storage of latent heat positioned within the interior volume of said plastic member;(iii) an electrically resistive heating element positioned in thermally conductive contact with said phase change material;(A) said heating element being controllable, upon direction of electric current therethrough, to heat said phase change material to a temperature sufficient for storage of latent heat therein;(B) said heating element being positioned within the interior volume of said plastic member;(iv) a thermal switch;(v) an electric power cord having a first end with a coupling, said first end and coupling being positioned exterior to the interior volume of said plastic member; said coupling is adapted to be coupled to at least one of a source of alternating current and a source of direct current; said electric power cord being in electrically conductive communication with said electrically resistive heating element, and(b) providing the warmer within an outer covering internal volume provided by an outer covering, said outer covering having at least one openable and closable end;(i) said outer covering is configured for storage of food, to be maintained warm, therein.