Abstract: An electrical toaster is provided with timer means which is initiated when a food product carrier is secured in an operative position adjacent a toasting element. The timer means normally releases the carrier from its operative position after a toasting interval. In the event of a malfunction, the timer means operates a cut-out to interrupt the supply of power to the toasting element within a predetermined period to prevent combustion or ignition of the food product. The latter period is longer than the normal toasting interval. The timer means may include first and second timing devices for respectively timing the toasting interval and the predetermined cut-out period. Alternatively the timer means provides respective outputs for controlling the toasting interval and the cut-out period.

Abstract: Automatic switching apparatus for a hand held electrically operated appliance such as a pressing iron. A motion sensor and an electronic timer cooperate to automatically shut off the iron if the iron remains stationary for a predetermined period of time. A simplified mechanism is manually operable in the event the user desires to reactivate the iron. A circuit board mounting simplified electronic circuitry is located within the handle of the iron. An appropriate indicator informs the user whether the iron is in the active mode or in the inactive mode.

Abstract: A hot food stand utilizes heat lamps to keep food warm. The lamps are automatically activated when food is placed on a pressure sensitive support positioned beneath the lamps. A modified embodiment of the invention senses the quantity and positioning of food on the support and activates additional heat lamps if needed.

Abstract: An insecticide dispenser capable of initiating the volatilization of a charge of insecticide to fumigate a room. The dispenser includes a container for the insecticide that is disposed upon a PTC heater. One side of the power supply necessary to initiate the chemical reaction passes directly through the cannister to the PTC heater. The other side of the power supply is connected through a support upon which the PTC heater rests. In the preferred embodiment, an electrical cut-off device is included in the circuit which will turn off the power when a predetermined temperature is attained which will be indicative of the initiation of the self-sustaining chemical reaction that causes the dispensing of the insecticide into the room.

Abstract: A microwave oven is disclosed including a turntable inside a cooking chamber, the turntable being provided with a weight detection device, a weight measuring device on a digital display for displaying a result of the food weight measurement produced by the weight measuring device. The word "approximately" or another appropriate term is also displayed together with a measured net weight value.

Abstract: An electrical connection installation for a cordless electric appliance, such as a flatiron, has an electrical contact part carried by a stationary base serving as a stand for the appliance and which is adapted to mate with the electrical contacts of the appliance when the appliance is placed on the base. The contact part is coupled to an electric power source in in the base by a switch having a pair of contacts normally biased to an open position by springs formed from curved sheet metal strips and which are closed by a magnetically reactive contact actuating member responsive to the proximity of a permanent magnet in the appliance when the appliance is placed on the base.

Abstract: A cooking plate or hob having a temperature sensor, the cooking plate or hob being provided with a central through hole in which a body supporting the temperature sensor is movably arranged. The body is operated by a spring in a direction towards the upper side of the cooking plate or hob, the movement being limited by a shoulder which cooperates with a surface on the body. The surface has a shape that coincides with the envelope surface of a rotating body of curved or conical shape. The shoulder connects to the upper side of the cooking plate or hob and the body takes the form of a cup-shaped thin plate which opens downwards and has a plane upper side and an annular skirt which is adapted to the through hole. The surface which cooperates with the shoulder connects the upper side of the thin plate with its skirt.

Abstract: A heating cooking appliance in which a Roberval mechanism, which produces a change in the vibration frequency in accordance with the weight of the food to be heated, is incorporated in a turntable, and the vibration of the turntable is transmitted to the outside of the heating chamber through a magnetic coupling using a magnet to detect a magnetic signal outside the heating chamber. In order to positively pick up the magnetic signal, a yoke is employed in the magnetic circuit and a detecting coil is arranged near the magnet by raising the heating chamber bottom plate, thereby tightening the magnetic coupling. Further, in order to eliminate electromagnetic wave noise, etc., a filter circuit is provided to ensure exact picking-up of the vibration signal. In order to avoid an influence on the magnetic signal of other magnetic field producing devices, the measurement is made either while such devices are not in operation or by using an added magnetic shielding means.

Abstract: A disposable canister for use in an electric fogger includes a container to hold a fog-producing material which is constructed of a material capable of transferring heat from a heat source to the fog-producing material, an insert secured in the container to close the container and having a dome with a discharge port to allow the release of a fog, and a cap secured to the container and having an opening which overlies the discharge port of the insert to allow the release of a fog and one or more lugs which serve to activate an electric fogger when placed in the housing of the electric fogger. The cap of the disposable canister also includes outwardly extending rims which seat on the housing of the electric fogger and in conjunction with the lugs of the cap serve to lock the canister into the housing. The invention precludes the escape of any fog from the closure seal between the container and the cap into the housing of the electric fogger and provides for fully efficient use of the fog-producing material.

Abstract: An arrangement comprises a hinge (4) positioned in the lowest region of the front surface at a front opening (2) in a heating chamber (1), a door (3) swingable around the axis of the hinge (4), and a weight detecting section (11) provided on the hinge (4) of the door (3) for detecting the weight of a heating load (20) by converting deformation produced by the load into an electric signal, wherein the weight of the heating load (20) placed on the door (3) when the latter is opened is detected by the weight detecting section (11). Accurate weight detection is possible no matter where the heating load (20) may be placed on the door (3). Tare subtraction weight detection is possible by utilizing a microcomputer. Further, it is also possible to automatically control heating operation in association with weight detection.

Abstract: A cooking apparatus comprising a rotary table disposed inside a heating chamber so as to mount food to be heated, and a motor which rotates the rotary table. The rotary table and the motor are integrally supported in a floating state by a resilient member, thereby allowing the food and the rotary table to vibrate or move vertically. This vertical vibration or movement is measured by employing a detector, and the weight of the food is measured from the output of the detector. The rotary table is provided with a biasing means interlocked with a door for regulating the height of the rotary table or stabilizing the same when the door is opened. In the case where the vibration of the rotary table is particularly detected, the rotary table is forced to vibrate by the action of the biasing means thereby allowing highly accurate measurement of the weight of the food.

Abstract: A heating apparatus comprises a housing having a chamber and a door for closing the chamber, and a power supply source to supply heating energy to the chamber. A door-close sensor is provided for detecting when the door is closed. A foodstuff is placed on a table which is vertically movably mounted in the chamber on a resilient support so that the table may oscillate at a frequency determined by the weight of the foodstuff. The housing may be constructed to transmit an impact to the table at the instant the door is closed, or alternatively, means are provided for causing the table to oscillate at the frequency in response to the door being closed. The oscillation of the table is converted to an electrical signal and analyzed to determine the weight of the foodstuff. The power supply source is controlled in accordance with the determined weight.

Abstract: A normally flat horizontal blanket-type waterbed heater unit having top and bottom laminates of thin flexible dielectric sheet plastic material and an elongate electric resistance element arranged and sealingly engaged between the laminates. A power supply cord connects with opposite ends of the element and extends from the unit. The unit further includes a normally open safety switch connected with and between related ends of sections of the element. The switch includes spaced terminals atop the bottom laminate, a contact bar above the terminals and below the top laminate and a resilient insulating support part between the laminates and adjacent the terminals and bar. The part normally yieldingly holds the bar and adjacent portion of the top laminate spaced above the terminals. The unit is arranged atop a water bed mattress supporting platform and below the bottom wall of a sheet plastic waterbed mattress bladder.

Abstract: A heating appliance includes a heating chamber for accommodating a food to be heated and a casing carrying the food, a weight measuring device for measuring a tare weight of the casing and a gross weight of the casing and the food disposed in the heating chamber, a calculation circuit for calculating a net weight of the food in response to the output of the weight measuring device, a first display for displaying the net weight of the food, and a second display for displaying the gross weight of the casing and the food.

Abstract: A portable hairsetter appliance for heating a single hair roller. The hairsetter comprises a cylindrical housing having an axially aligned and longitudinally extending high voltage electric resistance heating element encapsulated in a quartz envelope for heating a single hair roller inserted into the cylindrical housing. The weight of the roller closes an electrical circuit and the roller is heated to a predetermined temperature whereupon a thermoplastic bimetallic disc changes its concavity to open the electrical circuit. A safety means is provided to automatically open the electrical circuit if the roller is pressed into the housing with a force greater than its own weight.

Abstract: A towel warming apparatus contacts all of the outer exposed surfaces of a folded towel with a continuous flow of warm air and can be readily installed in the wall of a bathroom to warm a towel with heat drawn from hot water flowing through a conduit to a faucet. The warm air flows between inner and outer walls and passes through perforations in all the inner walls to contact the towel on all exposed surfaces.

Abstract: A temperature compensation injector control system as used in an electronic fuel injection system for motor vehicles utilizes the value of the voltage levels across the coil (18) to determine the coil's (18) temperature. A multiplexer (20) responds to the value of the source of power (14) and the voltage drop across the coil (18) created by a small leakage current to generate digital signals to a microprocessor (10) for modifying injector control signals.

Abstract: The temperature control of an electric blanket changes the preset temperature in accordance with the presence or absence of a human body so as to ensure comfortable sleeping. The preset temperature is changed to a higher temperature setting upon connecting the power source. When the user goes to bed so that the human body is detected by human body detecting means, the higher temperature setting is automatically decreased by setting changing means to the temperature preset by temperature setting means. Also, when the user rises for the time being after having fallen asleep, the preset temperature is automatically raised so that the user is again allowed to fall asleep comfortably.

Abstract: A heater-scale having a curved supporting member upon which a bag of fluid to be heated can be placed, has a distributed two-dimensional heating element affixed to a lower surface thereof. The curved member is supported by a load cell for generating an electrical signal proportional to the weight of the bag on the heater member, a thermistor is in contact with the fluid whose temperature is to be maintained, a thermistor is affixed to the heater member, and a control system senses the weight and temperature of the bag of fluid as well as the temperature of the heater member for the purpose of nonlinearly adjusting the electrical current supplied to the heater element as fluid is removed from or variable temperature fluid is added to the bag so as to maintain the bag at a predetermined temperature.

Abstract: A microwave oven comprises a weight detector for detecting the weight of a foodstuff to be heated, a condition detector for detecting a substance emitted from the food as a result of heating, and a control unit that responds to the output of the weight detector by setting a defrost time period in which the food is to be defrosted. The microwave energy is set to a low level during the defrost period. Upon the termination of the defrost, the energy is raised to a higher level and continued for a period of time determined as a function of the interval between the instant the defrost mode terminates and the instant the amount of the detected substance reaches a predetermined value.

Abstract: A cooking apparatus includes a rotary table which is disposed inside a heating chamber such as to mount a food to be heated, and a motor which rotates the rotary table. The rotary table and the motor are integrally supported in a floating state by a resilient member, thereby allowing the food and the rotary table to vibrate or move vertically. This vertical vibration or movement is measured by employing a detector, and the weight of the food is measured from the output of the detector. The rotary table is provided with a biasing means interlocked with a door for regulating the height of the rotary table or stabilizing the same when the door is opened. In the case where the vibration of the rotary table is particularly detected, the rotary table is forced to vibrate by the action of the biasing means thereby allowing highly accurate measurement of the weight of the food.

Abstract: An apparatus for monitoring the cooking process in a cooking vessel placed on an electric heating element, particularly a stovetop burner, comprising signal transmitter controlled by the temperature in the cooking vessel, a signal receiver in communication with the signal transmitter by a transmitter for activating a control circuit to adjust the heat output of the heating element, and a switch for turning the apparatus on and off. During the entire cooking operation and when the heating element is set at full heating capacity, a periodical surveillance is effected to determine whether the temperature varies, remains steady or decreases. If a temperature increase is measured during a monitoring cycle, the heating element is not turned off, but if the temperature remains constant or falls, the heating element is turned off.

Abstract: An apparatus for heating food-warmer plates includes a housing into which a plurality of the food-warmer plates may be slid through slots in a wall of the housing. An electrical heating element is disposed under each food-warmer plate inserted into the housing. The heating elements may be switched on and off individually. In this way it is possible to heat only that number of food-warmer plates which is actually needed.

Abstract: An alarm system for an electric range which detects when a burner is energized without a utensil in place on the burner wherein the sensing means comprises an electrical switch mounted below the stovetop having a first switch position and a second switch position, a pin slidably passing through an opening in the stovetop beneath the rim of the dish under the heating element in contact with the underside of the rim and biased against the rim with a pressure sufficient to lift the rim from the stovetop when no utensil is present on the heating element, but insufficient to lift the rim when a utensil is in place on the heating element; and means connecting said pin with the switch to operate the switch between first and second positions corresponding to the position of the pin when a utensil is present or absent from the heating element.

Abstract: An electromechanical system for generating heat in metallic vessels, includes a vessel which acts as a load resistance for the secondary of a transformer having a very low voltage and a high current. The voltage developed in the secondary of the transformer is applied directly to the vessel between two diametrically opposed areas comprising contact members on the vessel. Electrodes are engaged to press against the contact members and the electrodes are connected to the terminals of the secondary of the transformer. The system includes a mechanism for controlling the distance between the electrodes for separating the electrodes from the contact members on the vessel in order to remove or place the vessel between the electrodes and for moving the electrodes closer together with strong pressure against the contact members on the vessel for closing the electric circuit of the secondary.

Abstract: Microwave oven scale apparatus for coupling weight from the cavity and for providing a weight corresponding signal. The weight corresponding signal is used by a microcomputer to compute cooking times. Microwave transparent posts insert through holes in the floor of the cavity and support a tray on which the food is positioned. The posts respectively screw down on unitary studs that have legs which straddle a pivot member of the scale. The height of the studs can be adjusted by rotation on the studs. The studs are aligned vertically and horizontally by connection to a frame positioned below the cavity floor. The scale includes two parallel rails that are pivotally supported on their outward edges and have inwardly directed extender arms which couple together at a location where they are supported by a compliant member.

Abstract: This drop-down toaster has a bread support and a door at the bottom of each toasting compartment. The door has a series of vent holes for air convection which produces improved uniformity in the toast. The door and bread support are held closed by rollers on solenoid-controlled sliding bars. The rollers allow the door to swing open before the bread support is released, and they return the door and bread support to their normal condition automatically by a cam action. The bread support is cammed upwardly before release to dislodge bread from the toasting compartment guide wires. An electronic timing circuit is located in a base underneath and spaced vertically from the toasting section so that it is not affected by heat from the toasting section. The timing circuit is compensated in accordance with previous use rather than by sensing the temperature of the toasting compartment.

Abstract: A utensil removal detection arrangement for a cooking appliance incorporating an automatic surface unit. The duration of time intervals during which the sensed utensil temperature for a turned-on surface unit is less than a threshold temperature is measured. If such a time interval exceeds a predetermined time limit, the surface unit is de-energized and a user discernible signal is generated indicating to the user that no utensil is present on the surface unit.

Abstract: A power control arrangement for a cooking appliance incorporating an automatic surface unit for automatically detecting the occurrence of a boil dry condition for a utensil placed on the surface unit when operating in the Boil mode. In accordance with one form of the invention a boil dry condition is indicated when the rate of increase of sensed utensil temperature exceeds a predetermined reference rate, or the sensed utensil temperature exceeds a predetermined threshold temperature.

Abstract: A power control arrangement for an automatic surface unit in a cooking appliance which enables the user to select Warm, Simmer, Boil and Fry cooking modes and to select from a plurality of heat settings for each mode. The heat settings for each mode have associated with them a minimum steady state temperature and a steady state power level. The control system compares the output from a utensil temperature sensor with various reference values determined by the mode and heat setting selected and depending upon the comparison, operates the surface unit at the corresponding steady state power level or at a transient power level to rapidly bring the utensil temperature to the desired temperature for the selected mode and heat setting with minimum temperature overshoot.

Abstract: An electric appliance safety system including a hand-held appliance, a power input for receiving electric current, a two-pole switch for activating the appliance, a power cord connecting the appliance with the switch and a pair of manually operable control elements operatively coupled to the two-pole switch for controlling its position. A hanger box encloses the switch and control elements, except for protruding portions of the control elements, and is adapted to receive the appliance. When the appliance is removed from the hanger box, the protruding portion of one of the control elements can be pressed manually, until latched on the other control element, thereby closing the switch and activating the appliance. When the appliance is hung on the hanger box, the protruding portion of the other control element is pressed down, thereby releasing the first control element, opening the switch, and disconnecting the appliance.

Abstract: An induction heating process and apparatus for flameless heating of metallic dental laboratory tools, medical instruments, and the like. The induction heating coil is energized by placement of instruments within the annular zone formed by the windings of the coil, and differential light sensors are utilized to compensate for variations in ambient light levels.

Abstract: A box is provided with an opening in its top for receiving the blade-holding head of a safety razor with the end of the handle of the razor resting on the surface supporting the box. Means within the box directs heated air onto the head of the razor within the opening in the top of the box.

Abstract: Method and apparatus for detecting the boiling point of liquids being heated by a cooking appliance and automatically reducing the output power of the heat source, once the boiling point has been reached, to a level which will sustain a desired evaporation rate, by measuring the initial weight of the liquid to be heated; energizing the heat source at a predetermined power level, periodically measuring the weight of the liquid as the heating process continues; computing the rate of change of the weight of the liquid, and reducing the power level of the heat source to a lower power level when the computed rate of change exceeds a reference rate and increasing the power level when the computed rate of change is less than the reference rate once the boiling point has been reached. The first occurrence of a measured weight decrease greater than the reference rate signifies that the boiling point of the liquid has been reached.

Abstract: A weight measuring arrangement for a cooking appliance in which a surface heating unit also functions as a scale platform. A three arm cantilever beam supports the heating unit. A set of four strain gages measures the strain of the three support arms, with one gage each being attached to each of two identical support arms and the remaining two gages being attached to the third arm, which arms are constructed such that the strain measured by each of the gages secured to the third arm is one-half that measured by each of the gages secured to the two identical arms when the ends of all three arms are equally deflected by a utensil placed on the surface unit for heating. The gages are electrically connected in a Wheatstone bridge network such that the output voltage from the bridge network is proportional to the weight of the load carried on the surface unit. This arrangement can be used to monitor the weight of the items being heated, throughout the heating period.

Abstract: A rotary receptacle for use in a microwave oven includes a plastic housing, in which food may be inserted, with projections therein to mix the food within the housing as the receptacle turns. The axes of the receptacle, which are connected to the driving mechanism, may be offset from the longitudinal axis of the housing to produce a tumbling effect. The housing may be made of transparent plastic. Alternately it may be constructed of an open wire mesh.

Abstract: A plurality of magnetic field sensors are mounted adjacent the periphery of an induction heating coil of flat, spiral configuration which is energized by ultrasonic frequency energy to generate a time-varying magnetic field. The magnetic field sensors are connected in a ciruit to produce an output signal when a magnetic utensil load is placed asymmetrically with respect to the center of the induction heating coil. In response to sensor output exceeding a predetermined value a warning indication is provided. The ultrasonic energy level is reduced in response to the warning indication to minimize radio interference which would otherwise occur due to leakage magnetic flux.

Abstract: An alarm system for use in a stove having a burner and control device for turning on and off the burner is provided, including an audio/visual alarm device and an alarm circuit for activating the alarm device. A low-voltage power supply energizes the alarm circuit. A sensor is mounted with the burner for sensing the presence and absence of a utensil thereon. A first switch in the alarm circuit closes a first set of contacts in response to the control device being in the burner-on position. A second switch in the alarm circuit closes a second set of contacts in the absence of a utensil on the burner, thereby completing the alarm circuit and activating the audio/visual alarm device.

Abstract: Apparatus for controlled dielectric heating a plurality of thermoplastic preforms for blow molding is provided. The apparatus controls the energization of a plurality of electrode pairs by a radio frequency generator. The generator is equipped with a load current limit detector and the electrode energization is enabled selectively for a predetermined time or until a predetermined load current magnitude is reached. The choice of control is determined by the anticipated load as reflected by the number of preforms within the heating station. The generator is further provided with overload detecting means indicative of the occurrence of electrical arcing within the heating station and the apparatus has further means responsive to the arc detector for selectively momentarily or indefinitely deenergizing the electrodes.

Abstract: A binding apparatus, for attaching loose sheets to a folder or file provided with a binding agent, comprises a hotplate (2) against which the folder is inserted through an opening (4) defined between supporting means (5, 6). The hotplate is kept constantly heated, while a time circuit controlled by means of a push button unit (10) activates an alarm means (12) when a set time is at an end. The regulatable time circuit is always zeroed when the folder is taken out of the opening, since the folder affects a light beam across this opening to a photocell which is connected to the time circuit (FIG. 1).

Abstract: A stand for an electric iron incorporates an automatic time delay safety switch arrangement which reduces the chances of fires being started by an unattended iron and serves to save a substantial amount of electric energy by cutting off the current to the iron when it is left turned-on but unattended. The stand includes a hinged, spring biased platform of insulating material for supporting an electric iron during non-use periods. Placement of the iron on the platform causes the platform to pivot closing a normally open switch. Closure of the switch energizes a standard electrically energized time delay relay mounted on the platform. After lapse of a predetermined time period, the time delay relay actuates a manually resettable electric relay from a first condition allowing the electric iron to be energized from a power supply socket on the platform to a second latched condition whereby the iron is deenergized.

Abstract: A beverage dispenser in which a sensor provides an output corresponding to the level of the beverage in a storage reservoir from which the beverage is dispensed. In response to user actuation a dispensing valve is enabled for such a time interval, determined in accordance with the output of the sensor, as to compensate for variations in flow rate due to variations in the beverage level in the reservoir. The level sensor output is also used to control a level-indicating display and to disable the reservoir heater when the reservoir is empty. Preferably the sensor is a strain gauge adhered to the surface of a relatively thin resilient beam which supports a portion of the reservoir.

Abstract: An improved induction heating apparatus as applied, for example, to a cooking oven in which there is employed a magnet having a bore formed in it, with a thermistor being installed on the top plate of the apparatus in a position corresponding to the bore so as to eliminate possible breakage of the thermistor, while the curie temperature of the magnet member is set at a predetermined level for further improvement in safety.

Abstract: A device for controlling evaporation of a liquid has a container and a heating element for heating and evaporating liquid in the container. The container is disposed on a base plate which is supported by a leaf spring which allows the base plate to move between two microswitches depending upon the amount of liquid in the container. The microswitches are connected to a control circuit for activating the heating element and interrupt the flow of power to the heating element when little or no liquid is present in the container, or when a maximum amount of liquid is present in the container.

Abstract: When a top burner of the electric range is energized, a sensible signal means is simultaneously activated. This sensible signal means is deactivated by the act of placing a cooking utensil upon said energized top burner. Circuit means are provided for electrically coupling energy from the energized top burner of the electric range. Such circuit means will include electric switching devices which are operative to deactivate the sensible signal when a cooking utensil is placed upon the energized top burner.

Abstract: A utensil detection arrangement for an induction heating apparatus which provides a signal indicative of an off-center position of a cooking utensil supported on a cooking surface which overlies an induction heating coil. The detection arrangement comprises a conductive loop configuration located intermediate the heating coil and the cooking utensil in a plane parallel to the plane of the cooking surface and concentric with respect to the axis of the coil. The conductive loop is linked with the magnetic flux generated by the induction heating coil, which flux changes as a result of the position of a cooking utensil with respect to the axis of the coil and thereby generates a signal which changes in amplitude as a result of utensil position.

Abstract: An apparatus for pre-heating resin tablets comprising a resin tablet heater, a switch for setting a reference softening degree and a softening degree detector for the resin tablet. The detector includes a pressure source and a pressure transmitting member coupled to the pressure source and adapted for contact with the resin tablet. The pressure transmitting member is movable a distance representative of the softening degree of the resin tablet being heated due to deformation of the resin tablet.

Abstract: A sensor arrangement for an induction heating apparatus which monitors the position of a cooking utensil on a work surface and disables an inverter circuit powering a work coil if the utensil is located at an off-center position with respect to the coil, or if no utensil is present upon the cooking surface. The sensor arrangement comprises a plurality of sets of sensors at successively larger distances from the center of the work surface. Each set comprises a plurality of sensors arranged on an imaginary circle substantially equidistant from each other. Each sensor operates to provide an indication of the presence or absence of a utensil directly above the sensor. The sensors are monitored by a logic arrangement which indicates whether a utensil is properly centered, based on the fullness or degree of activation of the various sets. If the utensil is not properly positioned, the inverter is disabled and a signal advises the user of this condition.

Abstract: A control system for operating a radiant furnace for curing ceramic products, the furnace having a furnace chamber, heating elements for applying radiant energy to the chamber, and movable platform means for supporting the ceramic product to be cured in the chamber. The control system generates a sensor signal responsive to the furnace temperature which is algebraically added to an idle temperature signal, a maximum temperature signal and a ramp signal. The algebraic sum produces an error signal which is applied to a polarity detector for controlling the heating elements in response to a predetermined polarity. The polarity detector is strobed when the sensor signal reaches the maximum temperature signal. Prior to reaching idle temperature the energy to the heating elements is applied in controlled graduated incremental levels. The idle temperature condition is a variable independent of the maximum temperature setting.

Abstract: A food service device including a food-carrying cart which can be stored inside a refrigerator is provided with elements for heating the food before meals are served. The electrical system is comprised of switching devices which actuate the heating elements depending upon the presence and orientation of food trays on the shelf of the cart; a self-aligning coupling which can supply electrical power to the cart's heaters when the cart is placed in the refrigerator; and a timer which controls the duration of time the electrical heaters are energized to warm the food prior to service, and provide a keep-warm timing sequence for holding the heated food within a refrigerated environment.