Abstract: A convection cooking appliance includes a convection fan for establishing a convection airflow which is heated by a heating element including first and second sections that are symmetrically disposed about the convection fan substantially parallel to and downstream of the convection fan. Each of the first and second sections is formed so as to include at least three lobes and four 180° turns, while establishing a thin profile heating element. A convection fan cover extends across the convection fan and includes a main body portion having an outlet portion for directing the convection airflow into a cooking chamber of the appliance. The outlet portion includes an angled louver and a trip edge portion. The angled louver and trip edge portion cooperate to alter a direction of the convection airflow from being substantially parallel to the main body portion to being substantially perpendicular the main body portion.

Abstract: A cooking appliance includes an oven cavity, an electric heating element and a rapid cook heating system both of which being operable on either one of first and second supply voltages, and a controller including a memory module having stored therein first and second control algorithms. The controller will operate the cooking appliance based on one of the first or second control algorithm depending upon whether the cooking appliance is connected to the first or second supply voltages respectively. Preferably, the appliance includes a sensor for signaling the controller as to the presence of either the first or second supply voltage. In the alternative, the appliance can be manually set for use with a particular voltage supply.

Abstract: A sheathed electric resistive heating element support bracket constructed in accordance with the present invention includes first and second mounting portions interconnected through a transverse web portion. The web portion includes at least one heating element receiving journal and an edge portion along which is arranged a plurality of substantially circular lances. The substantially circular lances define a bore through which a mechanical fastener can pass to secure the bracket in a desired position. In this manner, the mechanical fastener and support bracket collectively serve as an electrical ground and an RF energy shield for the heating element. The heating element is secured into the journal through a snap-fit connection, while a crimping finger is also deformed over a portion of the heating element to fixedly maintain the heating element in the journal.

Abstract: A cooking appliance incorporates a convection heating system including a housing having an interior portion, a fan assembly, a heating element and an exhaust outlet duct. The exhaust outlet duct, within which is arranged a plurality of controlled vent openings, is positioned in a high pressure area of the convection heating system established about a periphery of the fan assembly and heating element. Oven gases are forced by the high pressure through the exhaust duct, thereby creating a corresponding reduction in pressure. The reduction in pressure establishes a low pressure area within the fan assembly which draws in fresh air in an amount equal to that exhausted through the exhaust duct.

Abstract: A microwave delivery system for a cooking appliance includes a toroidal waveguide, a launching zone and a waveguide cover. The launching zone includes opposing top, bottom and side walls that form a pathway for a microwave energy field to travel from a magnetron through the waveguide and into a cooking chamber. In accordance with one aspect of the overall invention, the bottom wall of the launching zone is aligned with a bottom surface of the waveguide to establish a direct conducting surface for the microwave energy field. The waveguide cover shields a hollow interior portion of the waveguide from cooking byproducts generated in the cooking chamber during a cooking process. The waveguide cover is preferably constituted by a metallic conductor having a finish that enhances the microwave energy field distribution in the cooking chamber.

Abstract: A rapid cook convection oven is constructed to efficiently cook a food item by breaking down a thermal insulation layer maintained about the food, while effectively removing contaminates from within a convection air flow. The rapid cook oven preferably includes both a microwave cooking system and a convection cooking system. The convection cooking system is provided with a dual flow fan adapted to simultaneously draw in an oven air flow from a cooking chamber and a fresh air flow from the surroundings. In order to reduce the presence of contaminates and, by extension, smoke, the two air flows are combined in a mixing chamber and passed over a heating element arranged within a combustion chamber prior to re-entry into the cooking chamber.

Abstract: A convection cooking appliance includes an oven cavity in communication with an air channel assembly incorporating a catalyst. The catalyst includes multiple stages defined by first and second, spaced honeycomb structures. The first honeycomb structure is arranged to initially vaporize the carbon cooking byproducts which then directed to the second honeycomb structure wherein the vaporized byproducts are broken down into carbon dioxide and water prior to being expelled from the catalyst. Between the first and second honeycomb structures is a gap which functions to create a turbulence for the delivery of the vapor to the second honeycomb structure.

Abstract: A cooking appliance includes an oven cavity, an electric heating system having a plurality of electric heat loads for heating the oven cavity, and a controller. The controller includes a memory module having stored therein at least first and second control algorithms for operating the electric heating system based upon an available current supply. If the cooking appliance is connected to a low current rated circuit, the controller will operate according to the first control algorithm and cycle activation of the plurality of heat loads in a manner not to overload the available current supply. Conversely, if the appliance is connected to a high current rated circuit, the control unit will operate according to the second control algorithm and enable activation of multiple heating loads simultaneously. Preferably, the appliance includes a switch or sensor for toggling between the first and second control algorithms.

Abstract: A microwave delivery system for a cooking appliance having a cooking chamber includes a toroidal-shaped waveguide, a magnetron, a tubular feed member interconnecting the magnetron with the toroidal-shaped wave guide and a field flux generator positioned about the tubular feed member. The flux field generator shifts a microwave energy field produced by the magnetron in the tubular feed member. The shifted microwave field focuses high energy standing waves that are directed into the toroidal-shaped wave guide and, ultimately, the cooking chamber. The field flux generator produces either magnetic or electrical fields and is driven by a pulsed DC current, a rectified AC current or a pure AC signal energy source.

Abstract: An accelerated cooking feature for use in an appliance having an oven cavity includes a forced air convection system having an electronic control unit, a variable speed, bi-directional fan motor, and a directionally vented cover plate. The appliance operates in at least three modes, constituted by a convection mode, a radiant bake mode and a self-clean mode. In the convection mode, the controller operates the fan motor in a first direction at a speed dependent upon a selected cooking process, with various air streams being directed into distinct regions of the oven cavity. During the radiant bake mode, the controller operates the fan motor in a reverse direction to establish a uniform cooking environment. In the self-clean mode, high speed air currents are directed into the oven cavity and, in combination with a top broil element, perform a pyrolytic cleaning process.

Abstract: A cooking appliance includes an oven cavity and a forced air convection system having a convection fan, a heating element and a ventilation system including a duct. The duct includes a first compartment adapted to receive an oven air flow, a second compartment adapted to receive an exhaust air flow, and an air inlet opening into each of the first and second compartments, wherein an incoming air flow is introduced into each of the first and second compartments through operation of a fan assembly. According to one aspect of the invention, the incoming air flow combines with the oven air flow prior to passing over a convective heat element. As such, the combined air flow is heated combusting food byproducts contained therein. In accordance with another aspect of the present invention, the incoming air flow is combined with the exhaust air flow, lowering the temperature of the exhaust prior to release to the surroundings.

Abstract: A self-cleaning sequence for a convection cooking appliance employs high velocity air to heat an oven cavity and components/ducting of an air circulation passage to self-cleaning (pyrolitic) temperatures. In accordance with the invention, the self-cleaning sequence includes four stages: a vent catalyst pre-heating stage; a low molecular weight hydrocarbon burn-off stage; a high temperature cleaning stage; and a cool down stage.

Abstract: A microwave delivery system for a cooking appliance includes an electronic control unit and a plurality of magnetrons arranged in a spaced relationship for the introduction of various energy fields into an oven cavity. The electronic control unit creates a phase angle shift between each of the microwave energy fields such that a constructive standing wave propagates about the oven cavity. In this manner, localized hot and cold spots, which can detrimentally affect cooking efficiency, are eliminated without the need for mode stirring or turntables. With this system, the total energy delivered to the oven cavity is the combined energy level of the various microwave energy fields.

Abstract: A microwave delivery system for a cooking appliance includes a toroidal waveguide and a launching zone. The launching zone has an interior metallic surface into which a microwave energy field is introduced. The microwave energy field couples with the interior metallic surface of the launching zone thus increasing the efficiency of the energy field as it enters the waveguide. Additionally, a tuning form section is provided in the waveguide which further enhances the microwave energy field, thereby creating a maximum energy node around the inside and outside of the waveguide. Insulation is provided both in the interior of the waveguide and in a central, exterior depression defined by the waveguide.

Abstract: A microwave delivery system for a cooking appliance includes a toroidal waveguide having a ring diameter twice that of the wavelength of the microwaves produced by a magnetron, and a cross-sectional diameter equal to one-half of the produced microwaves. The waveguide includes a plurality of cavity excitation ports through which the microwaves enter a cooking cavity. The delivery system further includes a rotating stirrer positioned within the waveguide. The stirrer includes a plurality of openings which become aligned with the cavity excitation ports when the stirrer is rotated to create a uniform, high energy pattern of microwave energy to enter the cooking cavity. Finally, the waveguide includes a plurality of openings along spaced portions thereof to allow a flow of air through the waveguide.

Abstract: A microwave cooking appliance includes a sheathed resistive electric heating element including an outer portion, an inner portion and a cross-over portion electrically interconnecting the outer and inner portions. The heating element is arranged in a cooking chamber of the microwave cooking appliance in a manner which effects an impedance characteristic of the cooking chamber. The cross-over portion is arranged such that the heating element acts like an RF antenna moving a microwave energy field to portions of the cooking chamber in which low electric fields occur. In this manner, the broil element helps increase the operational efficiency of the cooking applaince by minimizing any hot and cold spots within the cooking chamber.

Abstract: A quick-cook type convection cooking appliance includes an oven cavity in communication with an air channel assembly incorporating a radial byproduct trap and filter assembly defining a concentric ring-type baffle filter having two cylindrical sets of opposing air baffles. As recirculating air passes outwardly between deflectors of the baffle, the air is accelerated by a nozzle-type effect prior to impacting a center zone of an outer baffle deflector. This arrangement causes part of liquid and/or solid phases, such as grease, fats, and moisture, of the air flow to be deposited or trapped between the baffles. The air flow is then redirected back towards the inner baffle where, once again, the air impacts an inner baffle deflector that removes additional byproducts from the air. Finally, the air exits with a high uniform air flow pattern between respective deflectors of an outer baffle.

Abstract: A preheat system for a convection cooking appliance functions to control the operation of multiple heating units, the heating of a catalyst, and the speed of a blower assembly of the appliance to effectively eliminate grease, oils, and other hydrocarbon compounds from prior cooking operations, while also minimizing the generation of any appreciable amount of smoke. Additionally, the blower assembly is controlled to establish a negative pressure differential in the oven cavity upon opening of an oven door in order to assure that any smoke, as well as additional amount of oxygen for enhancing combustion, will be drawn into the oven cavity. The preheat system is particularly adapted to clean the oven cavity prior to a cooking operation and between self-cleaning cycles.

Abstract: A self-cleaning system for a convection cooking appliance controls the activation and deactivation of multiple heating units, as well as a blower, throughout an initial preheat and subsequent phases of a cleaning operation. In accordance with the preferred self-cleaning method, an initial, catalyst pre-heat stage is followed by a moderately high-temperature presoak stage. For the main cleaning operation, a high temperature stage is initiated in combination with a high convection air flow to establish high oven surface temperatures in a minimal time frame. This timed stage is followed by a cool down period wherein both the temperature and convection speed is reduced. Thereafter, an intermediate temperature heating stage with medium convective air flow followed by a cooling stage are provided for preset time periods. This combination of intermediate temperature heating and subsequent cooling stages is repeated until the total self-cleaning time is completed.

Abstract: A blower assembly for a cooking appliance having an oven cavity adapted to operate in at least cleaning and convection cooking modes includes a blower element mounted for rotation though a shaft member supported by at least one bearing unit. The shaft member is constituted by a tubular section which is secured to the blower element and a solid shaft section which extends within the tubular section. The solid shaft section is formed from a material having a higher thermal conductivity than the tubular section and concentrically arranged relative to the bearing unit. With this arrangement, the shaft section acts as a heat sink for directing heat, to which the blower element is subjected, away from both the tubular section and the bearing unit. The shaft section preferably terminates within the tubular section at a distance spaced from the blower element such that a thermal air gap is defined within the tubular section.