Abstract: Jets of heated gaseous fluid are perpendicularly directed against the surface of a food product, moving relative to said jets, such that the jets impinge against discrete points on said surface, before fluid in the jets is diffused, to wipe away the boundary layer of air and moisture from said discrete points. Heat is thus transferred to the surface of the food product at points upon which the jets impinge thereby increasing the temperature at said points.

Abstract: A ventilated stove for use in recreational vehicles and the like that includes an oven which is divided into an upper and lower compartment. Positioned between the upper and the lower compartments is a gas burner. A reversible blower communicates with the oven through a duct and can be selectively rotated for causing the air to flow upwards over the burner into the upper oven or downwards through the burner to the lower compartment of the oven. An access door is provided in the rear of the oven so that food can be inserted in the oven from outside of the vehicle. A valve means is provided in the duct for withdrawing combustible by-products from surface burners carried on top of the stove.

Abstract: A hot air oven for heating food-loaded cartridges, each constituted by a stack of sealed trays comtaining pre-cooked meals nested within an open carton whose side walls have holes therein to admit heated air. The oven includes a rotating turn-table for supporting an annular array of such cartridges, the side walls of which define a hollow center core. A heater assembly produces heated air which is blown by a propeller into the hollow core, some of this air being forced through the holes of the cartons to heat the food in the trays. The remaining portion of the heated air passes through a flow passage below the cartridges to be drawn upwardly by the suction force of the propeller to create an air curtain around the array, thereby creating a toroidal flow pattern which envelops the annular array. The oven is divided by a shield placed within the hollow core into a hot zone and an extra hot zone, the cartridges of the turntable travelling cyclically through these zones.

Abstract: In a high-frequency energy apparatus, a heat generating element is disposed on a ventilation path of the high-frequency energy apparatus, which path is channeled through a heating chamber. When the heating time is automatically controlled, external air is introduced into the heating chamber, and when the heating time is manually controlled by such a means as a timer, on the other hand, hot air which has been heated by the heat generating element is introduced into the heating chamber so that the deposition of dew on the wall of heating chamber and the obscuring of a viewing panel of the heating chamber due to moisture may be prevented.

Abstract: A food service system for institutional or other use is provided by a stack of insulated trays and a cart. In one embodiment the cart includes a heating and/or cooling source with an outlet and a return. The trays are provided with openings to permit the passage of heated or cooled air from the outlet through the stack to the return. In another embodiment the trays and cart are combined with a refrigeration unit and a heating unit to permit simultaneous heating and cooling of food portions held in the trays.

Abstract: An industrial process oven is provided with a false outer skin spaced from the oven wall. A plurality of air currents are induced and estalished in a like plurality of air passages provided between the oven wall and the outer skin. As ambient air passes over the oven wall it is preheated. The preheated air from the plurality of air passages is collected in a transfer duct and conveyed to an oven heater where its temperature is further raised to a desired operating temperature.

Abstract: An oven for baking bread and like products includes an oven chamber which is heated by supplying heated air to the chamber through horizontal slits in opposed side walls of the oven chamber. The oven may be converted for baking articles of a different size by the pivoting of means mounted in the oven adjacent selected horizontal slits between positions in which the adjacent horizontal slits are closed and positions in which the adjacent horizontal slits are open and additional trays may be supported in the oven chamber adjacent the selected horizontal slits. A forced air convection oven is therefore adaptable for use in making good quality products of a large size such as loaves, and also good quality products of a smaller size such as rolls.

Abstract: A method and apparatus for heating articles, such as eyeglass frames, includes a bed of heat retentive beads supported above a plenum chamber by a mesh or screen. Heated air is delivered to the plenum chamber at low velocity and high volume for flowing upwardly through the bed for heating the same. The air is directed through the plenum chamber by bodies which act as baffles as well as a heat sink.

Abstract: A microwave oven in which the amount of ventilation for a heating chamber is changed dependent upon whether the heating time is controlled automatically or whether the heating time is controlled by manually setting a timer or a like device, whereby the deposition of dew on the wall of the heating chamber and the obscuring of a viewing panel are prevented.

Abstract: A forced convection oven heated by burners in a combustion chamber beneath the oven. Hot gases pass via an outlet port into the restricted part of a pressure-reducing throat forming the central lower portion of a U-shaped passageway whose vertical limbs provide inlet and outlet manifolds to the oven cooking space. The shape of the throat ensures good mixing of these gases with gases circulated by a tangential or centrifugal type fan positioned upstream of the throat. The gas mixture from the inlet manifold enters the cooking space via a perforated side panel and travels across the oven and leaves through perforations in the side panel opposite and thence into the outlet manifold for re-circulation.

Abstract: The gas burner and blower powered oven includes a mixing chamber of appreciable length that receives bottom outflow air from the oven and, in general opposition, an input from the burner which includes make-up room air. A substantial flame is produced in the chamber for combusting volatiles in the oven outflow and the latter is mixed in the chamber before proceeding to the inlet of the blower, the latter discharging the hot air into the oven through a multiplicity of holes in a top manifold for downward substantially uniform flow throughout the oven.

Abstract: A microwave oven providing the combination of dielectric heating by the use of microwaves and resistive heating for scorching the surface of a food. An isolation chamber for accommodating an article to be heated by a resistive heater is formed adjacent to the resistive heater provided in a heating cavity. When heating by the resistive heater is desired, the article to be heated is accommodated in the isolation chamber so that it is heated either both by dielectric heating and resistive heating or solely by resistive heating for scorching in an effective manner and at the same time minimizing the contamination of the heating cavity. In this manner, the application of the microwave oven may be widened and the usefulness of the microwave is enhanced.

Abstract: An industrial oven having a housing defining a work chamber into which products to be treated by the oven may be placed includes a duct system communicating with a blower wheel mounted in the work chamber for communicating air blown by the wheel to the work chamber. The industrial oven further includes the improvement of a blower scroll consisting of a plurality of plates mounted about the blower wheel in an involute configuration. The blower plates define a plurality of outlets for uniformly directing air from the wheel to the duct system.

Abstract: A fast food service technique in which a meal is pre-cooked and then transferred to a tray in which the food is refrigerated at a temperature just above its freezing point to preserve the meal without degrading its texture or flavor. When the food is to be made available to customers, the cold trays are transferred to the open shelves of a heating apparatus which is adapted to blow hot air into the shelves to heat the food in the trays to a temperature well below its boiling point to prevent re-cooking thereof and to form a curtain of heated air surrounding the shelves to effectively isolate the trays from relatively cool ambient air, whereby the heated trays may be directly withdrawn by a customer from a shelf without heat loss and without the need to open a door.

Abstract: A hot blast type oven comprising an outer casing defining a heating chamber adapted to receive foodstuff to be cooked and having a front door for opening and closing the heating chamber. A main burner serves for producing hot gases sent to the heating chamber by a blower. A gas control section including an operation handle controls the supply of gas to the main burner and to a pilot burner adjacent thereto. An electrical control section serves for controlling the main blower and an ignition device for the pilot burner. The gas control section and the electrical control section are constituted as respective units coupled together and detachably mounted for mutual operation. The control sections are operated in accordance with movement of the door such that the operation handle is locked when the door is closed and lighting of the pilot burner can be achieved only by opening the door and displacing the operation handle.

Abstract: Disclosed is a domestic cooking range of the ventilated type having surface elements and an underlying oven characterized by an extension of the ventilating fan motor shaft carrying an auxiliary fan disposed within the oven which provides forced circulation of air in the oven. The oven may thus be selectively operated in the conventional radiant heating mode or in the forced circulation or "convected" mode depending upon whether the ventilating fan motor is in operation. The oven can be held at an elevated temperature (of the order of 550.degree. F) for a time interval to accelerate catalytic self-cleaning (catalyst added to the porcelain frit covering the oven surface) because of air circulation within the oven door and passages adjacent the door, this cooling air flow being induced by operation of the ventilating fan.

Abstract: Disclosed is an oven which may or may not be incorporated in a domestic cooking range. The oven is characterized by the presence of a fan inset in one side wall of the oven. A plate having upper and lower slots approximately aligned with the conventionally located upper and lower oven heating elements overlies the fan. The slots or openings in the plate provide discharge apertures for the fan so that the air streams from the fan sweep past the heating elements to provide forced circulation or "convected" mode operation. Since the oven heating elements are conventionally located, the oven may be operated in the conventional, radiant mode by halting operation of the fan. The oven is thus easily convertible to either radiant or convection mode of operation.

Abstract: A method for holding food and the like at desired temperature and moisture levels for an extended period of time wherein a holding chamber confines a volume of air about a food disposed therein, an air flow supply produces a stream of heated humidified air that is directed in a curtain-like vortex pattern around the outer perimeter of the inside of the holding chamber to form a core of relatively still, heated moisturized air about the food to transmit heat and moisture thereto without a significant amount of air flow in direct contact with the food. A power control circuit is used to selectively operate a blower motor that circulates the air in a closed air flow system, a heating element that heats the air, a removable food rack motor that rotates the food in the holding chamber and lights that illuminate the food in the holding chamber.

Abstract: An oven is disclosed having an inner shell forming a heatable oven chamber, a conveyor within the oven chamber, a layer of insulation around the inner shell, an exterior cabinet shell spaced outward from the insulation, and a fan for moving a flow of cooling air between the insulation and the exterior shell; also disclosed in the oven is an inlet to the oven chamber having separate inner and outer doors operatively connected together, an outlet from the oven chamber having a discharge chute directed into an exterior outlet frame with insulation between the chute and the frame, and a single electric motor connected to operate both the cooling fan and a friction drive connected to drive the conveyor.

Abstract: A food service system for institutional or other use is provided by a stack of insulated trays and a cart. In one embodiment the cart includes a heating and/or cooling source with an outlet and a return. The trays are provided with openings to permit the passage of heated or cooled air from the outlet through the stack to the return. In another embodiment the trays and cart are combined with a refrigeration unit and a heating unit to permit simultaneous heating and cooling of food portions held in the trays.

Abstract: A method and apparatus for baking food in a closed cooking space in which heated air is circulated. The temperature of this heated air is varied about a predetermined mean temperature value by generating a plurality of sequential heat radiation pulses, by means of electric air heaters or the like, of a predetermined amplitude, frequency, and duration for baking the food with a minimum of soiling of the cooking space.

Abstract: Disclosed is a plug-in circuit arrangement for a ventilated range which permits a single, manual switch to control the level of heat output of the rear electrical heating unit in a surface cooking plug-in cartridge and also the level of heat output of a plug-in broil unit depending upon which of the two is inserted in the range, with the wiring of the receptacle and the broil unit combining, when the broil unit is plugged in, to operate the motor of the ventilating fan automatically whenever the broil unit is energized by the control switch, the same control switch, when actuated, energizing only the rear heating unit of the surface cooking cartridge, and not the ventilating fan, when the surface cooking cartridge is plugged into the range.

Abstract: An apparatus and method for holding food and the like at desired temperature and moisture levels for an extended period of time wherein there is provided a relatively still volume of air about the food which is heated by maintaining a regulated, temperature controlled, recirculating flow of heated air in a closed passage with the air heated by a controlled heating element and recirculated by controlled air blowers about said volume of air along at least two pairs of perpendicular axes and about a major portion of the external surface area of the volume of air without a direct contact of heated air flow with the food to provide substantially uniform heating by conduction and convection. A controllable source of moisture in the form of a water pan in open communication with the heated volume of air introduces controlled quantities of moisture into the heated volume of air.

Abstract: A tunnel oven for bakery purposes has a plurality of horizontally- and vertically-spaced hot air supply orifices in each of its vertical walls. At least some and preferably all such orifices are individually adjustable slots. Each wall also has air extraction orifices connected to suitable ducting.

Abstract: An air curtain is provided across the top of a food warming table, such as is employed in cafeterias for keeping food hot for serving. An air stream flows across the top of the pans holding the cooked food, where it picks up heat, moisture and flavor components, and is continuously recirculated to form an air curtain. Which retards the outflow of moisture and heat from the surface of the food. Keeping a cushion of hot moist air on the food maintains it in a hot and moist condition. Additionally, the air curtain acts to keep dust and insects away from the food surface.

Abstract: Disclosed is a portable grill assembly adapted for use on, for example, a kitchen countertop area. The assembly includes a somewhat L-shaped housing, the horizontally extending portion of which encloses a heating element and is topped by a grill element for supporting meat or other edibles for exposed surface broiling. The adjoining upwardly extending portion houses a power driven fan which draws air, smoke and cooking vapors from across the grill element and into the upwardly extending portion. The fan outlet discharges to the exterior of the housing.

Abstract: Food products are baked in a forced-convection oven having a baking chamber into and out of which a rack carrying the food products on superposed trays may be rolled. Air is circulated horizontally through the baking chamber by a pair of vertically disposed cross-flow fans. The circulating air enters the baking chamber through alternate ones of two opposed side walls, and the major portion of it leaves the baking chamber through the other one of these side walls while a minor portion leaves the baking chamber through a back wall.

Abstract: An oven for treating food including a well of sheet metal material that is open at the top, a removable insert open at the top end located in the well, the side walls and bottom of the insert being spaced from the side walls and bottom of the well to define air circulating passages therebetween with the top of the circulating passages being open. The insert also includes a plurality of gill openings formed in the side walls of the insert, the gill openings having the open portion thereof facing upwards on the outer side of the insert to divert air from the air passages into the interior of the insert. The insert further includes openings at the bottom thereof for communicating the air passages with the interior of the insert. The oven further includes a removably fitted lid which forms the top thereof, and an air circulating fan depending from the lower side of the lid for drawing air upwardly out of the insert.

Abstract: An apparatus and method for holding food and the like at desired temperature and moisture levels for an extended period of time wherein a holding chamber confines a volume of air about a food disposed therein, an air flow supply produces a stream of heated humidifed air that is directed in a curtain-like vortex pattern around the outer perimeter of the inside of the holding chamber to form a core of relatively still, heated moisturized air about the food to transmit heat and moisture thereto without a significant amount of air flow in direct contact with the food. A power control circuit is used to selectively operate a blower motor that circulates the air in a closed air flow system, a heating element that heats the air, a removable food rack motor that rotates the food in the holding chamber and lights that illuminate the food in the holding chamber.

Abstract: A convection oven is disclosed in which a duct for drawing hot air from the combustion chamber conveys the hot air to the heating chamber, said duct extending through the ventilation chamber and communicates therewith; it also communicates with an outlet duct so as to convey all the air drawn from the combustion chamber and a fractional volume of the ventilated air towards the outlet duct. The advantages are a reduction of the temperature of the fluids and a finer adjustment of the temperature in the useful areas of the oven.

Abstract: A method and apparatus for baking food in a closed cooking space in which heated air is circulated. The temperature of this heated air is varied in a sawtooth fashion about a predetermined mean temperature value by generating a plurality of sequential heat radiation pulses, by means of electric air heaters or the like, of a predetermined amplitude, frequency, and duration for baking the food with a minimum of soiling of the cooking space.

Abstract: A food cooking oven has a closed muffle in which there is provided an axial-input radial-output blower that is rotated by a drive motor outside the housing so as to circulate gases in the housng in a closed path passing through the blower. At least one vane is provided in the housng at one of the sides of the blower so as to limit air circulation therein and prevent excessively strong currents of air in the housing from damaging delicate foodstuffs. This may be a disc vane in front of the axial input of the blower or a pair of elongaged vanes flanking the blower at the output sides thereof.

Abstract: Inherent heating of the air in an oven by a high-velocity recirculating blower is used as constant rate thermal energy source. Constant temperature is maintained by varying the rate of blending of source of cooler air with the heated oven air. Automatic control of temperature is provided by a variable vent operated by a thermal expansion bellows, and a second control means is employed to prevent the oven from exceeding an adjustable maximum temperature.

Abstract: The oven cooking cavity has a perforated top wall above which there is a substantially full width plenum chamber which receives from a rear exterior duct heated air and gases under pressure for discharge of the same downwardly through the cavity top substantially uniformly over the area of the same. The heated air and gases exit from the cavity at the bottom and comingle with newly heated air and gases from a bottom forward gas burner in passage therewith to motor-driven impeller means which discharges into the delivery duct. In such gas embodiment, a small portion of the circulation within the cavity is vented to the atmosphere at the top front of the oven and compensating make-up room air supplied. The heat source can also be electric, with full instead of substantially full recirculation as in the gas embodiment.

Abstract: Inherent heating of the air in an oven by a high-velocity recirculating blower is used as constant rate thermal energy source. Constant temperature is maintained by varying the rate of blending of source of cooler air with the heated oven air. Automatic control of temperature is provided by a variable vent operated by a thermal expansion bellows. The bellows is slightly responsive to ambient temperature to compensate for variations thereof.

Abstract: A domestic gas-fired oven having a top burner in the cooking cavity and a bottom burner fully concealed beneath the bottom of the cavity. The heated products of the bottom burner are caused to flow in a wrapper over the bottom and partially over the side walls to openings in the latter where these products enter the cavity. Air under pressure is supplied to the burners by a fan and another fan withdraws flue products from the top of the cavity, with the incoming air and the exhaust flowing through different sections of a rotating regenerator wheel for heat transfer therebetween. The burners can be operated separately for broiling and baking and together for high temperature self-cleaning of the oven.