With Temperature Or Current Control Means Patents (Class 219/441)
  • Patent number: 4292888
    Abstract: A coffee brewing device of the percolator type. Fundamentally, the invention comprises a pot for receiving liquid therein and having positioned at the bottom thereof a cylindrical pump member characterized by an essentially flat top and by a tubular pump chamber of greater radial length than the vertical depth of the pump chamber at the top of the pump member. Six to ten uniform holes or orifices of a total area of between about 0.0258 and 0.043 square inches are provided in uniformly spaced relationship about the bottom of the pump assembly. Received within the pump is a dual element fat-topped heater consisting of a core having two heating element wires wrapped thereabout in a parallel spiraling fashion. The flat top of the pump member is spaced from between 1/16" and 1/8" from the flat top of the heater.
    Type: Grant
    Filed: October 15, 1979
    Date of Patent: October 6, 1981
    Inventors: Alton R. Wells, Robert M. Wells, James L. Heir
  • Patent number: 4284878
    Abstract: Fluid level detection means utilizing a thermally conductive element in the general shape of a cone, in one embodiment, in direct contact with fluid whose level is to be detected. A portion of the element, excluding the apex, is directly heated. A thermal sensor is bonded to the apex. When the fluid depletes such that the apex is exposed to air, the temperature in the immediate vicinity of the apex rises to a new point of equilibrium. The sensor converts this elevated temperature into a signal recognized by electronic circuitry as a flow fluid level. This signal may subsequently be used to provide visual or audible alarm.
    Type: Grant
    Filed: August 20, 1979
    Date of Patent: August 18, 1981
    Assignee: Bourns Medical Systems, Inc.
    Inventor: Harold U. Bartels
  • Patent number: 4270039
    Abstract: An indicator is provided for a heating unit, which heating unit may be used as a soft contact lens disinfecting means, and which includes wax as a heat transfer medium, as a temperature stabilization means, and as a heat storage medium. In accordance with the present invention, an indicator assembly for such a heating unit is provided, and which indicates to the user when the unit is energized, when the unit has reached its proper operating temperature, and when the unit has completed a heating, disinfecting cycle. The indicator assembly of the invention is in the form of a hollow plug which extends into the interior of the heating unit, and which itself is filled with wax. The plug has an indicator disc, which may be of a bright color such as red, attached to its bottom to be visible through the wax in the plug and through the transparent cover of the plug only when the wax within the plug is in a transparent molten state.
    Type: Grant
    Filed: August 17, 1979
    Date of Patent: May 26, 1981
    Assignee: Rincon Industries, Inc.
    Inventor: Stephen G. Hauser
  • Patent number: 4242570
    Abstract: An electric skillet or the like cooking vessel includes a cooking pan and a removably attachable insulative handle having a temperature control assembly with a spring loaded temperature sensing "shoe". One portion of the side wall of the pan defines a raised temperature sensing area against which the "shoe" is pressed upon joining the pan and handle. A lip extends from the raised area and forms a recess between the lip and sidewall of the pan. A first end of a torsion spring mounted on the handle for rotation is received in the recess for engagement with the lip subsequent to joining the handle and pan and rotating the spring to a first, locked position. The opposite end of the spring is received beneath a shoulder provided on the handle, thereby twisting the torsion spring to cause the first end thereof to forcibly engage the lip.
    Type: Grant
    Filed: September 8, 1978
    Date of Patent: December 30, 1980
    Assignee: McGraw-Edison Company
    Inventor: Robert H. Clark
  • Patent number: 4241288
    Abstract: A rice cooker having a kettle for containing rice, an inner case surrounding and supporting the kettle, first and second heaters separated from each other and mounted within the inner case and adjacent the outside surface of the kettle for heating the kettle and the contents thereof and first and second switches electrically connected to the heaters to control the energization and deenergization of the heaters so as to heat the kettle by three heating stages to obtain boiled rice of most excellent taste.
    Type: Grant
    Filed: November 16, 1979
    Date of Patent: December 23, 1980
    Assignee: Tokyo Shibaura Denki Kabushiki Kaisha
    Inventors: Terutaka Aoshima, Tokihiko Ikemizu
  • Patent number: 4234783
    Abstract: In an electric rice cooker, an electric heater for heating a kettle containing a quantity of rice and water is firstly energized through a first contact of a switch sensitive to the temperature of the kettle. When cooking operation completes the switch transfers to a second contact to start a timer. After a predetermined time, the timer reenergizes the heater through the second contact for a definite interval.
    Type: Grant
    Filed: June 11, 1979
    Date of Patent: November 18, 1980
    Assignee: Tokyo Shibaura Denki Kabushiki Kaisha
    Inventor: Terutaka Aoshima
  • Patent number: 4230935
    Abstract: An immersion heater is disclosed having a heating member with a small thickness and comprised of PTC thermistor material. The heating member has the same heat contact between each of its two major surfaces and the medium to be heated. A Curie temperature T.sub.C and a specific resistance .rho..sub.T.sbsb.C of the material are dimensioned such that with a given operating voltage U a temperature regulation for the range with the positive temperature coefficient of the material results. By use of the upper limit of the Curie temperature T.sub.C, extensive protection against fire can be obtained in the case of inappropriate handling of the immersion heater.
    Type: Grant
    Filed: February 13, 1979
    Date of Patent: October 28, 1980
    Assignee: Siemens Aktiengesellschaft
    Inventor: Hans Meixner
  • Patent number: 4228136
    Abstract: A lens case for use with a dry heat sterilizer unit, or the like, wherein said sterilizer unit includes a substantially flat heated support surface with the lens case supportable thereon in intimate surface-to-surface heat conductive contact. The lens case is substantially flat and includes shallow, cup-like base and cover sections. The lens case base section includes separate, lens supporting arrangements for receiving a pair of lenses, said lens support arrangements being provided in side-by-side relation. The lens case is designed to be positioned on said support surface of said sterilizer unit only in an inverted position, i.e. with the cover engaged with said heated support surface, and said lens support arrangements inverted, which serves to prevent overheating of the lenses. Further, the cover member for the lens support arrangements, include central apertures, which permit the lenses to be engaged during opening of said covers, to preclude said lenses from adhering to said cover members.
    Type: Grant
    Filed: February 14, 1978
    Date of Patent: October 14, 1980
    Assignee: Ryder International Corporation
    Inventor: Michael D. Thomas
  • Patent number: 4223208
    Abstract: A heater is disclosed having a PTC thermistor heating element rigidly wedged in an intermediate space of the member to be heated by use of at least one wedge-shaped member. The wedge-shaped member has a surface which is at least the size of the heating elment so an optimum heat transmission is guaranteed.
    Type: Grant
    Filed: March 30, 1979
    Date of Patent: September 16, 1980
    Assignee: Siemens Aktiengesellschaft
    Inventors: Peter Kleinschmidt, Hans Meixner
  • Patent number: 4217482
    Abstract: A control circuit useful in commercial cooking appliances, such as deep fat fryers, having electric heating elements and separate operating and safety controls including full power transmitting contactors for independently energizing and/or deenergizing the heating elements. The simplified control is economical, but reliable, and utilizes the safety control contactor connected in series power circuit with the heating elements and a single relay to establish both an on operating circuit for normal cooking conditions where the operating control cycles on and off to maintain the desired operating temperatures and a safety circuit that deenergizes all heating elements should an overheat condition occur and further that requires manual release or reset to again render the appliance operative.
    Type: Grant
    Filed: May 16, 1977
    Date of Patent: August 12, 1980
    Assignee: McGraw-Edison Company
    Inventor: Gurinder S. Wadia
  • Patent number: 4187412
    Abstract: An automatic control for egg cookers, baby bottle warmer, etc. is designed around a conventional slide switch of the type normally biased to the open position. Manually actuated means are provided to move the slide switch to its ON position, whereupon a mechanical latch automatically latches onto the knob of the slide switch to hold it in its ON position. When the cooking has been completed, a bi-metal releases the latch and permits the biasing means to open the switch and terminate the heating.
    Type: Grant
    Filed: July 10, 1978
    Date of Patent: February 5, 1980
    Assignee: Sunbeam Corporation
    Inventors: Peter J. Ernster, Ernest Canamero, James B. Cockroft
  • Patent number: 4177375
    Abstract: A heating device is disclosed having a disc-shaped heating element consisting of PTC thermistor material typically operated by a network voltage of 220 volts. The PTC thermistor material has a cut-off control property at a desired cut-off temperature so as to minimize further heat rises of the heating element above the cut-off temperature. In this fashion, the possibility of fire damage is reduced. The heating element has a specific heat output of greater than 50 watts per cm.sup.2 and the PTC thermistor material is selected to have a Curie temperature which is at least 50.degree. K. higher than the cut-off temperature. A heating body is provided to affect a substantially even dissipation of heat from two sides of the heating element.
    Type: Grant
    Filed: September 28, 1978
    Date of Patent: December 4, 1979
    Assignee: Siemens Aktiengesellschaft
    Inventor: Hans Meixner
  • Patent number: 4165456
    Abstract: A presser member, into which the container is loaded, is manually depressable against the action of its return spring into pressure-contact engagement of the container with an electric heating plate containing a PTC heating resistor. The depression stroke produces closure of a switch to energize both the PTC resistor and an electromagnet keeping the presser member in its depressed condition. A timer circuit opens the switch at the elapse of a prealably experimentally determined heating time during which the liquid reaches its consumption temperature, whereby heating is terminated and the return spring lifts the pressure member with the container to unloading position.
    Type: Grant
    Filed: October 2, 1978
    Date of Patent: August 21, 1979
    Assignee: P. Ferrero & C. S.p.A.
    Inventor: Amilcare Dogliotti
  • Patent number: 4164644
    Abstract: A heating unit for heating the contents of a container includes an electrical circuit having a pressure responsive switch that is normally open and a thermally responsive switch that is normally closed, the pressure switch is responsive to a predetermined weight of the container on a pivotally mounted heating element for activating the switch to the closed position for activating the heating circuit. The thermal switch is responsive to an overheating of the unit to interrupt the circuit. The heating unit is provided with a heating element having a conical center portion surrounded by an annular flat or planar surface, for receiving containers having only a predetermined shaped bottom for accommodating the particular shape of the heating element.
    Type: Grant
    Filed: August 7, 1978
    Date of Patent: August 14, 1979
    Assignee: Courtesy Interstate Corporation
    Inventors: Duane C. Remsnyder, Clarence C. Haynes
  • Patent number: 4164645
    Abstract: A device for heating a drink in a thermoplastics container sealed by a metal cover, in which the container is placed in a support upside-down and depressed to bring its cover into contact with an electrical heater, the depression of the container support operating a microswitch which energizes the heater and a support-retaining electromagnet to heat the container for a timed interval. The resistance of the heater is measured during heating by a Wheatstone bridge and utilized to regulate the temperature reached by the heater.
    Type: Grant
    Filed: January 16, 1978
    Date of Patent: August 14, 1979
    Assignee: P. Ferrero C. S.p.A.
    Inventor: Amilcare Dogliotti
  • Patent number: 4160152
    Abstract: A heating unit is provided in the form of an open topped container with a side wall and a bottom. The side wall has a plurality of bosses each of which has a plate-receiving groove. The bottom has on its upper surface elongated seat defining flanges, a barrier wall projecting between and extending laterally beyond a pair of seat defining flanges to separate the seats and to separate a pair of wires, and labyrinth walls defining a strain-relief circuitous wire passage. A pair of spring terminals are provided, each having a U-shaped part defined by two divergent leg parts one of which is seated in one of the seats and the other of which extends upwardly away from the bottom to a free end. A disc of PTCR material is mounted on the spaced free ends. A plate is snapped into the plate-receiving grooves of the bosses.
    Type: Grant
    Filed: December 4, 1978
    Date of Patent: July 3, 1979
    Inventors: John W. Wightman, Lawrance W. Wightman
  • Patent number: 4158126
    Abstract: A heating unit which may be used as a soft contact lens disinfecting unit and which embodies a case construction entirely of thermoplastic, or other low heat-conductive material. A heat conductive liquid such as molten wax, or oil, or both, is contained in the case and is used as a uniform heat transfer medium between electrical heating elements in the case and the surface of an incubator supported in the case which, likewise, is formed of low heat-conductive material. The heating unit in the embodiment to be described, is specifically constructed to produce or aid in disinfecting so-called soft contact lenses intended for wearing in contact with the eye. The unit is more generally applicable, and may be used to advantage, when a low cost heating unit is desired which will raise the temperature of an object or a material to a given temperature, maintain it at or above the given temperature for a given time period, and then allow it to cool down and return to an ambient temperature condition.
    Type: Grant
    Filed: September 19, 1977
    Date of Patent: June 12, 1979
    Inventor: Lamont J. Seitz
  • Patent number: 4156808
    Abstract: A cooking utensil that includes the combination of a heat transmitting metal bottom wall, preferably stainless steel with a heat generating source including a high heat-conductive metal body, preferably aluminum, the bottom wall having a substantially planar lower surface and said high heat-conductive metal body presenting a flat surface to the lower surface of the bottom wall, a plurality of releasable clamping devices carried by the bottom wall and projecting therebelow generally peripherally of the high heat-conductive metal body at spaced intervals therearound each clamping device including a threaded post and nut threadably engageable therewith and including a resilient washer for engaging and urging the metal body upwardly into full resilient abutment with the lower surface of the bottom wall and a releasable rigid support formation carried by the margins of the bottom wall to embrace and engage the metal body from below to bear upwardly thereagainst over the range of applied temperatures to thereby con
    Type: Grant
    Filed: January 17, 1978
    Date of Patent: May 29, 1979
    Inventor: William M. Bardeau
  • Patent number: 4155291
    Abstract: An automatic coffee brewing machine is provided with a heater for heating the pump apparatus for forcing water therethrough, thermostatic switch means associated with the pump apparatus for sensing the completion of the brewing cycle, and circuit means including the switch means effective upon completion of the brewing cycle for changing the power output of the heater from the high level required for brewing operation to a much lower level required to prevent reinitiation of the brewing cycle. A heating unit for a carafe holding brewed coffee has heating means associated with the circuit means for producing heat both during and after the brewing cycle, the heat produced during the brewing cycle being greater than that produced after the brewing cycle.
    Type: Grant
    Filed: August 30, 1978
    Date of Patent: May 22, 1979
    Assignee: General Electric Company
    Inventors: William D. Ryckman, Jr., Charles L. Kemp
  • Patent number: 4147925
    Abstract: A percolator is provided with a preassembled partition plate heater assembly wherein a one-piece non-corrosive metal partition plate has a centrally located pump well. An annular heat distribution plate surrounds the well and is fixedly connected to a bottom surface of said plate. A main heater coil surrounds said well and is mechanically coupled to said heat distribution plate. An auxiliary heater coil is radially outwardly from said main heater coil and is mechanically coupled to said heat distribution plate. A thermostat is in direct contact with a bottom surface of said partition plate and is releasably supported by said heat distribution plate.
    Type: Grant
    Filed: April 26, 1978
    Date of Patent: April 3, 1979
    Assignee: Kidde Consumer Durables Corp.
    Inventor: Irving R. Belinkoff
  • Patent number: 4100394
    Abstract: A container or reservoir for liquid to be heated, has a pump well and heater assembly secured to and depending from the bottom wall of the container, and a pump and pump tube assembly can be positively locked on the well for pumping function but is easily and quickly removable for cleaning or replacement. The assembly is locked on the well by a retainer plate fixed to an outer pump tube and having locking portions coactive with locking portions on the side wall of the well, with said outer tube being telescopically slidable and rotatable on an inner pump tube which carries a pump plate to seat in the well and a valve disk co-operative with said valve plate. A compression spring is disposed between the retainer plate and the pump plate locking portions to hold the retainer plate interlocked with the well locking portions and to hold the pump plate seated in the well.
    Type: Grant
    Filed: December 12, 1975
    Date of Patent: July 11, 1978
    Assignee: Adams Industries, Inc.
    Inventor: George E. Tilp
  • Patent number: 4095089
    Abstract: A push button switch assembly for use in association with a heating element which heats a liquid medium or the like. The switch assembly generally includes a housing, a first switch mounted in the housing and movable between on and off positions, and a second switch mounted in the housing movable between on and off positions. The second switch is mechanically associated with the first switch so that the second switch is movable from its off position to its on position when the first switch is moved from its off position to its on position. The first switch is also electrically connected to the heating element to turn the element on and off. The first switch is actuated by means of a manually depressable push button mounted on the housing for moving the first switch from its off to its on position. A bimetallic element is provided between the first switch and the liquid medium for moving the first switch from its on position to its off position when the liquid medium reaches a given temperature.
    Type: Grant
    Filed: October 18, 1976
    Date of Patent: June 13, 1978
    Assignee: Molex Incorporated
    Inventor: Albert F. Ditzig
  • Patent number: 4095090
    Abstract: An improved container for heating beverages, soups, stews and like foods containing liquid matter which includes at least one electric heating unit embedded within the side and/or bottom walls of the container, said heating unit being connectable to a source of electric energy, and means responsive to the position of the container with respect to the supporting surface interposed between said heating unit and the electric energy source for switching on or off electric current to the heating unit.
    Type: Grant
    Filed: December 27, 1976
    Date of Patent: June 13, 1978
    Inventor: Anthony Pianezza
  • Patent number: 4063068
    Abstract: A portable food serving receptacle capable of heating chilled or frozen food to cooking or serving temperatures and automatically maintaining food at serving temperature. The receptacle consists of thin metallic walls and utilizes a flexible heating element of electrical and thermal insulating material. The heating element is adhered to the metallic walls of an inner dish of the receptacle. The insulating material of the heating element forms a laminated structure in which the electrical resistor is embedded. The walls of the receptacle have a substantially higher thermal conductivity than the laminate. The rate of heat flow from the heating element to the interface of the food and metallic walls of the receptacle is controlled by the thermal insulating characteristics of the laminate so that gradients of heat entering any given point of the food are substantially equal and are maintained at temperature levels below the scorching temperature of the food.
    Type: Grant
    Filed: August 12, 1976
    Date of Patent: December 13, 1977
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: David G. Johnson, Robert D. Thorson
  • Patent number: 4051346
    Abstract: An improved electric heating system for removable application to the bottoms of stock watering tanks. It consists of a substantially rigid heater element connected in series with a surface thermostat, for energization from a suitable electrical source. The element is forced into heat transfer relation with the outside of the bottom of said tank, and is rigidly connected to a thermostat bracket which simultaneously provides good heat transfer from the tank to the thermostat.
    Type: Grant
    Filed: March 10, 1976
    Date of Patent: September 27, 1977
    Inventor: Voigt O. Lenmark
  • Patent number: 4046989
    Abstract: Means for varying the heating rate of an immersion heater in a hot-water extraction unit comprising a solution tank in which an electrical immersion heater is mounted in order to decrease the warm-up time of the unit. In the preferred embodiment, the means comprise (a) a first heating element having a first watt rating; (b) a second heating element having a second watt rating, lower than the first watt rating; and (c) means for selectively actuating one or the other of the two heating elements.
    Type: Grant
    Filed: June 21, 1976
    Date of Patent: September 6, 1977
    Assignee: Parise & Sons, Inc.
    Inventors: Carl Parise, Ralph Eugene Blackman, James M. Wimsatt
  • Patent number: 4013869
    Abstract: The present invention is a device for warming and hydrating tortillas that have been cooked at an earlier time and have subsequently become cold and hard. A base for the device has a heating element with a thermostat control. A cylindrical container is located above the heating element. Inside of the cylindrical container is a rack held a predetermined distance above the bottom of the cylindrical container by downwardly extending legs. A lid closes the top of the cylindrical container.
    Type: Grant
    Filed: April 12, 1976
    Date of Patent: March 22, 1977
    Inventor: Maria Amelia Orts
  • Patent number: 4009368
    Abstract: A yoghurt-making machine comprises an enclosure inside which a receptacle containing milk pots is disposed above a basin. The space between the receptacle and basis is partly filled with a fusible material, such as commercial paraffin wax which has a cooling curve exhibiting a solidification plateau at a temperature near to the optimum temperature of yoghurt formation. A heating resistor attached to the basin is immersed in the fusible material which is thereby heated. The basin has a bottom defining with the enclosure a closed chamber completely separated from the fusible material. A temperature-limiting element is connected to the resistor and disposed so as to be responsive only to the air temperature within the chamber and is operable to terminate the heating of the fusible material when the temperature in the chamber is higher than the solidification plateau of the fusible material.
    Type: Grant
    Filed: September 6, 1974
    Date of Patent: February 22, 1977
    Assignee: Etud S.A.
    Inventors: Andre Faivre, Pierre Tanguy
  • Patent number: 4007367
    Abstract: This invention relates to an apparatus for thawing frozen semen for use in artificial insemination of animals. More particularly, the system relates to an apparatus for thawing semen while retaining maximum cell yield by minimizing loss of semen activity.
    Type: Grant
    Filed: February 2, 1976
    Date of Patent: February 8, 1977
    Inventors: Robert K. Rusteberg, Robert J. Froehlich
  • Patent number: 3995141
    Abstract: A food warmer comprising a heat transfer plate with a flat portion and a flange of thermally and electrically conductive material to which at least one pill of positive temperature coefficient of resistance material is conductively secured and an electrically insulative base with a trough for receiving the rolled edge of the heat transfer plate. The pill is provided with an electrically conductive coating on its two opposite faces. An electrically conductive spring is mounted in the base adapted to make contact with one surface of the electrically conductive coating of the pill. Electrical connection is made to the heat transfer plate and to the spring to provide a current path through the pill upon positioning and sealing the rolled edge with a silicon rubber sealing compound thereby providing proper contact force and alignment between the spring and the conductive coating of the pill along with a water tight seal.
    Type: Grant
    Filed: October 31, 1975
    Date of Patent: November 30, 1976
    Assignee: Texas Instruments Incorporated
    Inventors: David Pierre Vieau, Youn Hung Ting
  • Patent number: 3984656
    Abstract: This disclosure pertains to an apparatus for use in heating containers of food, as in cans, bottles, plastic pouches and the like by emersion into water adapted to insure uniform heating thereof by substantially insulating the containers from thermal contact with all the parts of the heating apparatus except the water in contact with the container. The apparatus can also be used to heat water alone, brew coffee, tea or other beverages.
    Type: Grant
    Filed: June 18, 1975
    Date of Patent: October 5, 1976
    Assignee: Lawrence Peska Associates, Inc.
    Inventor: William Thomas Morgan
  • Patent number: 3969610
    Abstract: A liquid heating device is used to heat a liquid at a preselected time for a predetermined length of time such as in percolating coffee. The device broadly consists of a cylindrical container having a closed bottom base, a removal top lid cover, a pouring spout affixed to the sidewall of the container as well as a U-shaped handle affixed to the sidewall of the container. A transparent tube is provided as a means of indicating the liquid level within the container. A control panel on the bottom outside periphery of the sidewall of the container has an inlet electrical receptacle, an indicator light unit, a two way switch assembly, and a timer assembly.
    Type: Grant
    Filed: January 20, 1975
    Date of Patent: July 13, 1976
    Assignee: Lawrence Peska Associates, Inc.
    Inventors: Helen Ratti, Charles Ratti
  • Patent number: 3950632
    Abstract: A probe mounting apparatus adapted for use in the deep fat frying of French fries, fish, chicken and the like, wherein the length of cooking time is to be calculated by a timing computer responsive to the temperature of a predetermined portion of the cooking medium as sensed by a probe assembly including a stiff sleeve formed of a smooth surfaced metal and containing a temperature sensing element at its end. The probe assembly is repeatably and accurately attached to the fryer and immersed with its sensory element in a precise location in the cooking medium by means of a mounting apparatus comprising: a mounting block fixedly attached in a predetermined location on the fryer and having an opening therein, such as a slot, arranged to receive the probe sleeve and to define the position of the probe's longitudinal axis in the cooking medium.
    Type: Grant
    Filed: April 14, 1975
    Date of Patent: April 13, 1976
    Assignee: Food Automation-Service Techniques, Inc.
    Inventor: Louis E. Rivelli
  • Patent number: 3940589
    Abstract: A portable cooking installation consists of a heat-insulated enclosure containing a plurality of separately controllable electrical-resistance heating element surrounding and at least partially defining a space to receive a cooking vessel. For instance, two, three or four strip elements formed into circles of progressively increasing diameter (reckoning upwards) lie horizontally around a common axis to define a space to receive a suitably tapering cooking vessel; the elements can have aligned planar inner surfaces and be mounted on a resilient common support to improve vessel/element contact.
    Type: Grant
    Filed: November 20, 1973
    Date of Patent: February 24, 1976
    Assignee: Tup! (Panama) S.A.
    Inventor: Earl Silas Tupper
  • Patent number: 3938498
    Abstract: In apparatus for deep fat frying, control circuitry is provided for regulating the temperature of heating elements. During cooking the heating elements are immersed in cooking fluid and are maintained at a selected temperature by an operating thermostat. Two high limit thermostats are provided to turn off the heaters if the temperature exceeds a predetermined safe limit. For cleaning, the heating elements are raised out of the cooking fluid and automatically disconnected from the operating and first high-limit thermostats. The heaters are cyclically actuated and deactuated by a thermal time delay relay, to gradually raising the heater temperature to achieve pyrolytic cleaning of the heating elements. The second high-limit thermostat turns off the heating elements when a predetermined temperature is reached, ending pyrolytic cleaning.
    Type: Grant
    Filed: February 18, 1975
    Date of Patent: February 17, 1976
    Assignee: The Frymaster Corporation
    Inventor: George M. Price
  • Patent number: 3931494
    Abstract: An improved warming container which may comprise either a cup, pot, bowl or the like, and which includes an electric heating element built into its bottom and side walls, the heating element being connected to a rechargeable battery, thermostat and switch located on its underside and which are completely enclosed so to allow the vessel being fully submerged during washing without damage to the electric system.
    Type: Grant
    Filed: April 1, 1975
    Date of Patent: January 6, 1976
    Inventors: Barbara Fisher, George Spector
  • Patent number: RE29609
    Abstract: The improved operating-safety control uses an operating contactor and a safety contactor each having normally open switch contacts and means connect these switch contacts on opposite sides of and in main power series circuits with the electric heating elements of the cooking apparatus effective for controlling electric input to same. An actuating coil is effective for closing each contactor switch contacts, and the control includes an operating thermostat and a safety thermostat each having a heat sensor in the cooking environment and each having a heat sensor in the cooking environment and each having normally closed contacts opened responsive to a set sensed high temperature. The control connects main on and off switch means operatively in series with a parallel hookup connection of the safety contactor actuating coil as one leg and the serially connected operator contactor actuating coil and operating thermostat controlled contacts as the other leg.
    Type: Grant
    Filed: December 23, 1976
    Date of Patent: April 11, 1978
    Assignee: McGraw-Edison Company
    Inventors: Gurinder S. Wadia, Harnek S. Gill