Heater compartment for lunch box

Claim 1

A SELF-CONTAINED FOOD HEATING DEVICE COMPRISING A RECTANGULAR HOUSING OF A SIZE SO AS TO BE SNUGLY RECEIVED WITHIN A PORTION OF THE RECTANGULAR FOOD STORING COMPARTMENT OF A CONVENTIONAL LUNCH BOX, ELECTRIC HEATING ELEMENTS SECURED TO INNER SURFACES OF THE HOUSING, A HOLLOW OPEN-ENDED CYLINDRICAL HEAT CONDUCTING MEMBER WITHIN THE HOUSING, MEANS CENTRALLY LOCATING SAID CYLINDRICAL MEMBER BETWEEN THE HEATING ELEMENTS, A FOOD CONTAINER REMOVABLY RECEIVED SNUGLY WITHIN SAID CYLINDRICAL MEMBER, A TOP ON SAID HOUSING, SAID TOP INCLUDING A CENTRALLY LOCATED APERTURE THERETHROUGH, SAID APERTURE HAVING A DIAMETER SUBSTANTIALLY EQUAL TO THE DIAMETER OF SAID CYLINDRICAL MEMBER, SAID MEANS FOR CENTRALLY LOCATING SAID CYLINDRICAL MEMBER CONSISTING OF A DEPENDING PERIPHERAL FLANGE ABOUT SAID APERTURE, SAID DEPENDING FLANGE BEING SNUGLY RECEIVED WITHIN THE UPPER END OF SAID CYLINDRICAL MEMBER, ONE WALL OF SAID RECTANGULAR HOUSING BEING OFFSET INWARDLY FROM THE EDGES OF THE TWO ADJACENT WALLS SO AS TO FORM A CHAMBER EXTERIOR OF SAID HOUSING, AND AN ADJUSTABLE THERMOSTAT CONNECTED IN SERIES WITH SAID HEATING ELEMENTS, SAID THERMOSTAT BEING LOCATED WITHIN SAID CHAMBER, AND MEANS CONTACTING SAID CYLINDRICAL MEMBER FOR TRANSFERRING HEAT THEREFROM TO SAID THERMOSTAT.