Abstract: A microwave oven has a cooking chamber in which an electric heater is provided to perform convection cooking as an alternative to high frequency cooking. Heat from the heater is circulated within the cooking chamber by a heat-circulation fan situated behind an apertured back wall of the cooking chamber. A cooking chamber disposed behind the heater houses a motor for driving the heat circulation fan and also for driving a cooling fan disposed in the cooling chamber. The cooling fan draws in cooling air through cool air apertures formed in the rear of the oven. Hot exhaust air from the cooking chamber is discharged through exhaust holes formed in the rear of the oven, next to the cool air apertures. In order to minimize the travel of hot exhaust air from the exhaust holes to the cool air apertures a guide duct mounted on the rear of the oven directs the exhaust air from the exhaust holes upwardly to a discharge outlet at the top of the duct.

Abstract: An apparatus and method for cooling a thermopile of a microwave oven which is capable of achieving a desired automatic cooking operation by effectively preventing the thermopile from being heated beyond a predetermined level irrespective of the change of the temperature of a heating chamber, wherein the apparatus includes a cooling fan provided at a bottom portion of an electrical components mounting compartment, an air duct provided above the cooling fan for selectively guiding outside air drawn in by the rotation of the cooling fan through a suction inlet to flow either to the inside of the electrical components mounting compartment, or to an upper portion of a heating chamber, and cooling air flow guides attached on the upper surface of the heating chamber, for guiding the cooling air flowing to the upper portion of the heating chamber to be moved towards a thermopile thereat.

Abstract: In a device (1) for the treatment of materials under the action of heat, and if appropriate also pressure, in a heating chamber consisting of a housing (2), containing the heating chamber, having a charging opening for the heating chamber which can be selectively opened or closed by means of a door (4), and a heating device (6), in particular a microwave heating device, for the heating chamber (7), the door (4) is so mounted that when a particular pressure in the heating chamber is exceeded it lifts off from the door frame (2) and is movable into a relief-opening position, out of which position it is moveable back into the original-closed position--after reduction of pressure--either automatically or by the application of force.

Abstract: A convection microwave oven has a high frequency generator for microwave cooking, and an electric heater for convection cooking. The heater is disposed within a cooking chamber at an upper portion thereof. A channel is disposed outside of the cooking chamber and communicates with the cooking chamber through an air inlet and an air outlet formed in vertically spaced relationship in a rear wall of the cooking chamber. A fan is situated within the channel adjacent the air inlet for drawing air from the cooking chamber via the air inlet, and discharging the air back into the cooking chamber via the air outlet. The air outlet is positioned to direct the discharged air toward the electric heater. The cross-sectional area of the channel can become either larger or smaller from the air inlet to the air outlet.

Abstract: A method for automatically controlling cooking by using a vapor sensor in a microwave oven is disclosed. The method for automatically controlling cooking air-cools the cavity for a predetermined time by means of the driving of a fan motor during the automatic cooking operation, and respectively compares magnitude and phase of a signal-processed detecting signal supplied from a detecting signal processing circuit section with magnitude of reference detecting signal and values of reference phases in order to discriminate the polarity of the signal-processed detecting signal. Also, the executing time of the air-cooling operation related to a cooking chamber, which is additionally provided in response to the discriminated polarity, is discriminately adjusted.

Abstract: A microwave oven has a food-receiving cavity and a magnetron for delivering microwave power to the cavity. The magnetron is supplied with a high voltage through a transformer, and a variable impedance is connected in series with the primary winding of the transformer. The resistive heating effect produced by primary current is utilized to heat the air in the oven cavity, and the magnitude of the impedance is variable to vary the output of the magnetron.

Abstract: A microwave oven includes a cooking chamber in which either microwave cooking or hot air convection cooking can be performed. A cooling chamber is situated rearwardly of the cooking chamber for housing a motor and cooling fan. A rear cover of the cooling chamber includes air intake and air exhaust holes formed therein for circulating a cooling air flow produced by the fan. The cover includes a vertical central surface in which the air intake holes are formed, as well as additional surfaces extending obliquely forwardly from respective edges of the central surface. The additional surfaces include a top surface, a bottom surface, and right and left side surfaces. Each of those additional surfaces, except for one of the side surfaces, includes air exhaust holes. Each of the air exhaust holes includes a rearward projection extending thereabove to resist the entry of water.

Abstract: An improved sensor malfunction prevention apparatus for a microwave oven capable of preventing a malfunction and an infrared ray sensor from being polluted by dusts, food debris or the like from a cooking chamber, which includes a cooling fan; an air duct for guiding cooling air introduced into the interior of the microwave oven in cooperation with the cooling fan; a sensor support bracket disposed at a predetermined inner portion of the air duct; a sensor disposed at a predetermined potion of the sensor support bracket; a protective cover support disposed at the upper portion of the sensor support bracket for defining air openings between the protective cover and the sensor support bracket; and a protective cover fixed to the protective cover support.

Abstract: An oven is capable of cooking food in a microwave mode or in a simultaneous microwave/convection mode. During the microwave cooking mode, a first fan blows outside cooling air through an electrical component compartment and then into a cooking chamber via through-holes formed in a partition wall separating the compartment from the cooking chamber. During the simultaneous microwave/convection cooking mode, cooling air is prevented from entering the cooking chamber via the through-holes by an air curtain established across the cooking chamber side of the through-holes. The air curtain is established by a second air circulator which blows heated air into the cooking chamber in a direction toward the through-holes.

Abstract: This invention discloses an improved safety device for microwave oven having one thermostat commonly preventing possible overheat of the cavity and magnetron of the microwave oven. The thermostat is placed in a position suitable for sensing both a peripheral temperature of a magnetron and a temperature of an air exhausted from a heating cavity through an air exhaust port. The thermostat cuts off the outside electric power for the microwave oven when the peripheral temperature of the magnetron or the temperature of the exhaust air coming out of the heating cavity is higher than a predetermined allowable temperature. The air exhaust port is provided about the magnetron. The thermostat mounting bracket is connected to the magnetron mounting bracket.

Abstract: A magnetron assembly that is adapted to be mounted on a wall of a waveguide in a microwave oven includes a yoke enclosure in which is disposed a magnetron tube. The yoke enclosure is generally U-shaped with an open top end and open opposite ends to permit air flow through the yoke enclosure and past circular disc shaped cooling fins that are affixed only to an anode assembly about the magnetron tube. Different configured mounting plates can be detachably disposed in the open top end of the yoke enclosure. A filter box has input power terminals for the magnetron tube extending therefrom and is mounted with respect to a bottom wall of the yoke enclosure such that the yoke enclosure can be rotated to various positions relative to the input terminals extending from the filter box.

Abstract: A microwave oven has a cooking chamber and a microwave generator for supplying microwaves to the cooking chamber. The microwave generator is in the form of a klystron which produces a plurality of electron beams for amplifying microwaves.

Abstract: A dielectric oven for heating a product with a tray includes a housing having an access, wherein the housing defines a heating cavity. The oven includes an oven liner which substantially conforms to the interior shape of the heating cavity and forms a liner cavity within the heating cavity. The liner is made from a non-electrically conductive material which may have a low dielectric constant, a low dielectric loss tangent, and a melting point of at least about 225.degree. F. (107.degree. C.). The liner forms a vaportight boundary between the liner cavity and the heating cavity. The liner material may be a thermoplastic resin selected from the group consisting of polysulphone, polyester, and polycarbonate resins. The liner material may be reinforced with, for example, glass fibers, such as in fiberglass reinforced polyester resin. The housing and the liner may have at least one air intake port and at least one exhaust port. At least a pair of contacts may project into the interior of the oven liner.

Abstract: A microwave oven having a heater and a wall structure, includes a heater cover disposed between the heater and the wall structure and a plurality of protruding portions formed on the heater cover and on a depressed portion of the wall structure, respectively. The heater cover includes a bent portion formed at its peripheral edge, and a hanger, for hanging the heater, is fixed to the heater cover to prevent the heat transfer in every direction from the heater. In addition, the protruding portions are brought into contact with each other and are fixed by rivets. The microwave oven further includes an air conduit for guiding an air flow produced by a fan to a space between the wall structure and the heater cover.

Abstract: An oven, particularly with an apparatus for pyrolytic self cleaning, includes an oven wall having an exhaust opening formed therein through which exhaust produced during oven operation can flow out to the outside. A throttle automatically adjusts an exhaust flow cross section of the exhaust opening or of a flow conduit adjoining the exhaust opening.

Abstract: This invention relates to a method for controlling a ventilation motor of a microwave oven which is provided to control the ventilation motor automatically according to a setting time by a user.

Abstract: A microwave oven cavity 2 is provided by a magnetron(s) with microwave energy for providing heat in the thermal cavity. Hot air is supplied by a heated air supply and director (21,22,24). Cool air, at least a portion of which is able to assist in containing and/or directing at least a portion of said hot air, is also supplied via a sleeve (31) so as to provide localization of at least a portion of said hot air in the thermal cavity, and optionally to prevent or reduce heat reaching at least a portion of the boundary of the thermal cavity.

Abstract: Disclosed is a cooling device of a microwave oven which can be easily assembled on a rear wall of a microwave oven with reduced noise, improved cooling efficiency, and increased space efficiency of a machine chamber thereof. The cooling device has a fan cover disposed on the rear wall and having a plurality of pores formed therein. Side panels of the fan cover extend inward with such an inclination that the inner surfaces of the side panels confront a cooling fan. The fan cover protrudes backward from the machine chamber, and has a dent replacing a separate spacer for ensuring the introduction of air through the pores regardless of the place at which the microwave oven is installed.

Abstract: A non-toxic extermination device is disclosed herein having an RF radiation generator providing microwave, high frequency waves for penetration through solid obstacles such as walls, floors, partitions or the like. The generated waves are characterized as being effective to cause insect internal molecular friction to generate deadly heat.

Abstract: A complete unit for simultaneous production of warm air and microwave energy is ready for delivery. The device contains three transmitters with wave-guides (8) for microwave energy, power components (9) and a fan (10). The fan blows cooling air past the power components and transmitters. The heated air can be used for removal of the water, that the microwave transmitters vaporize. The device can easily be moved from one cavity to another. With three transmitters connected one on each phase a balanced load of the mains is achieved. An induction motor drives the fan.

Abstract: In a microwave heating device, a propeller fan is mounted on a drive shaft of a motor that in vertically positioned parts of a high frequency power supply unit are arranged in the order of a power control semiconductor device and a high-voltage transformer along the direction of revolution of the propeller fan. The motor is secured to a support member formed by a motor cover attached to the casing of the propeller fan. The fan and high frequency power supply unit are mounted to a first frame and a second frame, both of which are bent and connected at a connecting portion and fixed in an approximately "L" shape, while an airflow path is defined by a first guide wall and a second guide wall to cool the parts of the high frequency power supply unit. An airflow path is formed by a plurality of guide walls provided on the two frames, and a communicating hole is provided in proximity to the connecting portion of the two frames. The propeller fan is so arranged as to revolve at a low r.p.m.

Abstract: An apparatus and method for heating water using a microwave powered boiler. The apparatus consists of a three cabinet arrangement which permits the dry incorporation of wave guides and the tunneling of microwave energy completely around and into a seamless water chamber. The apparatus can be adapted to provide a hydronic heating system, a forced hot air heating system, a tankless domestic hot water supply and a hot water heater.

Abstract: A cooking appliance has a cooking compartment accessed by a door. After cooking is finished, a sensor detects the temperature within the cooking compartment. Then a cooling fan cools components in the cooking appliance for a period of time dependent on the detected temperature. A control circuit changes the period for cooling in accordance with the time that the door is open while the fan is on.

Abstract: Cooling apparatus of a magnetron having a plurality of embossed cooling fins for radiating high temperature heat generated by an anode of the magnetron. Each of the cooling fins includes an anode support boss for tightly receiving and supporting the anode, a pair of erected walls being provided at both sides of the cooling fin, and a plurality of embossments for causing cooling airflow to be forced toward the rear surface of the anode and providing a cooling passage. These embossments are provided between the anode and the erected walls in order to symmetrical to each other with respect to the cooling airflow. The embossments comprise a plurality of protruded embossments provided at a side of the cooling fin and a plurality of depressed embossments provided at the other side of the cooling fin. The protruded and depressed embossments have an interval which is gradually shortened such that it is minimized at the rear of the anode.

Abstract: A device for heating substances under the development of high pressures in a microwave field is disclosed. Those parts of the device lying in the microwave field comprise material transparent to microwaves. The device comprises a pressure-resistant cylindrically shaped outer container and a cylindrically shaped inner container disposed inside the outer container. Both the inner and outer container is provided with a cover or a cap for closure thereof. An interspace is provided between an inner jacket surface of the outer container and an outer jacket surface of the inner container, which space is connected with a space outside the device via connecting channels. The interspace preferably contains a cooling media which is transported to and from the interspace and outer space via the connecting channels.

Abstract: A variable frequency microwave furnace system (10) designed to allow modulation of the frequency of the microwaves introduced into a furnace cavity (34) for testing or other selected applications. The variable frequency microwave furnace system (10) includes a microwave signal generator (12) or microwave voltage-controlled oscillator (14) for generating a low-power microwave signal for input to the microwave furnace. A first amplifier (18) may be provided to amplify the magnitude of the signal output from the microwave signal generator (12) or the microwave voltage-controlled oscillator (14). A second amplifier (20) is provided for processing the signal output by the first amplifier (18). The second amplifier (20) outputs the microwave signal input to the furnace cavity (34). In the preferred embodiment, the second amplifier (20) is a traveling-wave tube (TWT). A power supply (22) is provided for operation of the second amplifier (20).

Abstract: An apparatus for use in analyzing materials for ash content includes a walled chamber which retains microwave radiation therein, a source of microwave radiation, such as a magnetron, for radiating onto contents of such chamber, and an ashing furnace in the chamber which includes a heat resistant wall of low thermal conductivity, which is transmissive of microwave radiation, and a microwave absorptive material which is capable of being heated by microwave radiation to an ashing temperature. The furnace includes a passageway through it for the entry into the furnace cavity of a gas, such as air, and for venting gas, such as combustion products, from the furnace cavity, and preferably also includes a removable trapezoidally shaped door in a front wall thereof, which, when the chamber door is open, is readily removable from the furnace by hand, without burning the operator's fingers, despite the high internal temperature in the furnace cavity.

Abstract: A microwave oven has a magnetron 26 cooled by a fan 30 which generates a flow of air which is admitted to the oven cavity 10 through an inlet aperture 32, leaving the cavity through an outlet aperture 36. A grill element 22 is located in the upper part of the cavity 10 and a turntable 24 is positioned in the lower part of the cavity 10. Where the air respectively enters and leaves the cavity, thermocouples monitor air inlet (Ti) and air outlet (To) temperatures. After cooking commences, the air inlet and air outlet temperatures are monitored. After a time dependent on the load of the food item being cooked, the plot of air outlet temperature against time crosses the plot of air inlet temperature against time. The crossover point 44 of the air inlet and air outlet temperatures is used to control the remaining cooking time and the duration of energisation of the magnetron and the grill element during the remaining cooking time.