Abstract: Method and apparatus for testing microwave oven cavities during the oven fabrication process after the cavity forming operation is complete. The cavity to be tested is positioned front frame resting on a test plate containing a non-protruding microwave power source and choke/ferrite attenuators. The power source radiates into the interior of the cavity and microwave leakage is measured at the cavity exterior.

Abstract: A microwave oven browning system incorporating a combination microwave and hot air convection oven. The microwave cooking is carried out by use of a magnetron feeding a waveguide having a top branch on the top wall of the oven, a side branch on the side wall of the oven, and a bottom branch on the bottom wall of the oven. The convection cooking is carried out by directing heated air through a plurality of inlet openings in the top wall of the oven which are dimensioned to progressively increase in size in a downstream direction to ensure even distribution of heated air to the oven and a return air opening in the lower portion of the oven which ensures that air will flow over the top and bottom of food being cooked in the oven.

Abstract: A unitary air conditioner unit adapted to be mounted through a wall opening of an enclosure to be conditioned including an air sensing system operative for generating a signal dependent on the level of gases in the enclosure air. The control is operable for adding outside air to the circulating enclosure air or for exhausting enclosure air when a first level of gases sensed and for causing an alarm to sound when the level of gases is above a predetermined value.

Abstract: 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.

Abstract: A rack for use in a microwave oven cavity wherein the microwave energy enters the top of the cavity and the cavity has a rectangular shaped bottom shelf and sidewalls. The rack includes a metal rectangular framework of parallel bars and the framework is spaced inwardly of all sides of the cavity. The rack has legs depending from the corners of the framework and extending downwardly and diverging outwardly from the framework. Each of the legs has low loss dielectric insulating material on the terminal end thereof and the legs cooperate with the oven cavity bottom shelf and sidewalls such that the framework of the rack is centered relative to the cavity sidewalls and electrically insulated therefrom. With this rack two levels of food may be cooked simultaneously in the microwave oven.

Abstract: A self-storing meal rack for a microwave oven having an indexing mechanism for holding the rack in a lower or cooking or an upper storage position. The rack is rotated about a pivot between the cooking and storage position. Clearance is provided in the upper storage position so that the rack does not interfere with the polarization of excitation of the oven even though it is stored adjacent the upper wall of the oven cavity. In the lower or cooking position, the rack is spaced from the lower wall of the oven cavity a distance sufficient to permit food to be placed on the bottom wall of the oven cavity.

Abstract: A microwave oven having an upper waveguide and a bottom waveguide is provided with an adjustable microwave energy deflector. The deflector is adjustable for varying the microwave energy selectively in any power ratio between the upper and lower waveguides so as to obtain a uniform distribution of energy through food masses of different sizes or temperature characteristics.

Abstract: A power disconnect assembly for a plug-in electric heating element adapted to support and heat a cooking vessel and its contents. The assembly includes a terminal block with terminals for receiving the plug-in heating element and supplying electrical power thereto. A double pole switch with contacts connected to line voltage and to the terminal block is provided and a solenoid is utilized to open and close the double pole switch. Means are provided to detect the presence and absence of a cooking vessel on the heating element and means cooperating with the cooking vessel detection means to deenergize the solenoid in the event of cooking vessel absence and open the double pole switch thus terminating electrical power to the terminal block.

Abstract: A control system for a top plate surface heating unit having a softening temperature. The control system incorporates a temperature setting means for determining the operating temperature of the surface heating unit and means for automatically limiting the temperature of the surface heating unit to a temperature below the softening temperature of the top plate.

Abstract: An induction heating apparatus having a cooktop including a plurality of induction surface heating units. The cooktop comprises a horizontally disposed planar metal support surface having a plurality of openings therein. A ceramic smooth-top plate is supported in each of the openings and adapted to support a cooking utensil thereon. An induction heating coil is supported subjacent the ceramic plate in a position to generate a magnetic field which passes through the plate to link the cooking utensil. Each plate is supported by a metallic trim frame, which abuts a conductive layer on the plate, the frame and layer combining to provide a low reluctance flux path, the low reluctance path operating to reduce the magnetic flux leaked into the space surrounding the heating apparatus during operation thereof.

Abstract: A method for making a combination heater and temperature sensor comprising the steps of forming a heater element pattern in a thin sheet of resistive material and concurrently forming a temperature sensor in a non-interfering portion of the same sheet of resistive material, the forming of the heater and sensor element patterns being carried out by a photoetching process.

Abstract: A cooking oven having both microwave and electrical resistance heating means and which fully utilize the capabilities of a limited-capability power source to achieve the shortest possible cooking time. The oven has a microwave energy generating system which requires less than all of the available current when operated at its full rated power level, and an electrical resistance heating element which requires substantially all of the available current when operated at its full rated power level. The oven also has a means for at least successively energizing the microwave energy generating system and the electrical resistance heating element at their respective full rated power levels. Additionally, there is a means for energizing the electrical resistance heating element from the power source at a reduced power level when the microwave energy generating system is energized at its full rated power level.

Abstract: In a cooking oven supplied from a power source of limited capability, a time ratio control system alternately energizes a microwave energy generating system and an electrical resistance heating element a plurality of times during each cooking operation to, in effect, time share the available power. The resultant concurrent microwave and electrical resistance provides improved cooking results when the power source capability is limited.

Abstract: A microwave oven for cooking food with microwave energy on a slow simmer cycle. The oven includes a closed vessel in which food is to be cooked slowly for many hours at a simmer temperature. A control apparatus is furnished for monitoring the temperature of the food in the vessel, and it has a temperature-sensing probe adjacent the bottom wall of the vessel. The probe is connected in circuitry for controlling the power level of the microwave energy to medium power, as well as controlling the maximum food temperature to just below a boiling temperature.

Abstract: A broiling oven formed by an oven liner and an access door. Two electric radiant heating elements are located beneath the top wall of the oven liner. A hinged reflective plate is supported at each side of the innermost heating element. When these plates are lowered they form a miniature broiling compartment using the innermost heating element. When they are raised both heating elements may be operated together or separately.

Abstract: An electric range for household cooking purposes has a cooktop with a plurality of surface heating units in the form of coils of metal-sheathed, electrical resistance heating elements. Each unit is mounted in an opening in the cooktop. A combined reflector pan and trim ring is interposed in the opening for supporting the unit, for radiating the heating energy in an upward direction and for collecting spillage. The combined pan and trim ring is manufactured of the optimum materials so it will perform its functions, and, moreover, may be cleaned in a pyrolytic self-cleaning oven without injury or discoloration.

Abstract: An electric baking and broiling oven with an upper broiling element adjacent the top wall and a lower baking element adjacent the bottom wall. The baking element is of unique design having vertically arranged terminal ends supporting a plug connector. A mating plug receptacle is located in the rear wall of the oven liner slightly below the mid-height to receive the plug connector of the baking element.The baking element is reversible, in that its plug connector may be inserted in the plug receptacle upside down, so the baking element can be inverted and arranged closely spaced from and parallel to the upper broiling element. Both heating elements are to be energized during broiling. A shelf is positioned between the two heating elements so food placed thereon may be broiled on both top and bottom sides simultaneously.

Abstract: A sliding latch mechanism for the door of a heated cavity, such as a microwave oven that is provided with a pyrolytic self-cleaning oven cycle. This latch mechanism has a handle with only two positions; namely, a first unlatched position and a second latched position. The second latched position has two separate modes or functions; namely, an unlocked function and a locked function. The first unlatched position of the handle may be considered as providing an unlatched function. This first unlatched position of the handle is used for opening the door when needed, or when cooking within the oven with standard radiant heating means. The second latched position of the handle in its unlocked mode is used for microwave cooking alone or for combined microwave and radiant cooking.