Abstract: An electrically conductive resinous composition of a copper flake, the surface of which has been cleaned by removing therefrom impurities and/or oxides, a resinous binder, an amount of copper flake in said resinous composition being from 25 to 70 percent, the impurities in said copper flake being less than 7000 ppm, said resinous composition being cured with a curative comprising a polyamide or an anhydride, or mixtures thereof; these compositions are suitable for uses such as heating panels or conformable heating shapes.

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.

Abstract: A flexible tape, adapted to be rolled into a coil and to be cut into sections of any desired length, includes an elongate carrier of woven cloth impregnated with a flexible, carbon-containing resistance layer and a flexible heat shield, coextensive with the carrier, on one side of that layer, this assembly being enveloped in a flat sheath of synthetic resin. A surface of the sheath on the side of the heat shield may be coated with adhesive for detachably securing a backing strip of paper thereto. Two transversely spaced conductors, extending adjacent the longitudinal edges of the tape over the entire length thereof, are in conductive contact with the resistance layer for facilitating the passage of a heating current therethrough. The ends of the conductors in a section cut from the tape can be bared by removing parts of the sheath, the carrier and the heat shield. Several such sections can be laterally juxtaposed for the heating of a larger area.

Abstract: An electrical cooking or heating unit comprising a plate of a glassy material inluding a selected portion thereof upon whose upper surface vessels are to be placed for cooking purposes. The lower surface of the selected portion of the plate is provided with at least one sinuous strip of a gold/platinum alloy which integrally forms the electrical resistance heating element for the heating or cooking unit. A porous and partially sintered overglaze or coating covers the heating element and the portion of the lower surface of the plate on which the heating element is provided, such glaze preventing or inhibiting cracking, peeling or agglomeration of the heating element to provide a resultant increase in electrical resistivity. The life of the heating or cooking unit is thereby substantially increased.

Abstract: A removably mountable electrothermal print head for writing dots-matrix characters while moving along a thermosensitive recording medium and a mounting for the hand or a movable carriage of a printer, the head comprises a plurality of electrically energizable resistive printing elements coated on a support; the outer surface of said elements is partly cylindrical with the generatrices in parallel relation with a common direction which is transversal with respect to the printing line of the recording medium. The print head is positioned with respect to the recording medium with the part-cylindrical outer surface of the resistive printing elements in tangential relation with the recording medium. The printing head is positioned on and removably fixed to the carriage by a manually actuatable latch.

Abstract: An exothermic type printing head is provided including a substrate, and electric conductors and exothermic elements mounted on the substrate. At least one common electric conductor is mounted on the substrate. Each common conductor has a plurality of branches extending therefrom. A corresponding plurality of discrete electrically conductive elements are also mounted on the substrate. Each of the electrically conductive elements is longitudinally arranged between a pair of branches extending from the common conductor. At least one integral exothermic element of predetermined width is mounted on the substrate overlying the discrete electrically conductive elements and branches of each common conductor. Signals are supplied to the common conductors from a common source.

Abstract: An improved incubator includes a heated door which increases temperature uniformity inside the incubator.

Abstract: A thermal printing head provided with a plurality of electric heating members for recording information on a recording material, such as heat-sensitive paper. The heating members are voltage-dependent resistive elements and are mounted on a support member in the form of a substrate. Means are provided for the selective supply of current to one or several of the elements. At least some of the elements are constituted of silicon carbide.

Abstract: Glass-substrate thin film thermal printheads are protected from both chemical contamination and the mechanical wear by a coating comprising aluminum oxide (Al.sub.2 O.sub.3) over silicon monoxide (SiO) disposed on the printhead.

Abstract: An electrical circuit panel having provisions for mitigating joint failure of soldered connections thereof. An electrical conductor is formed by an electrically conductive coating(s) on a support. The conductor has a discontinuity formed therein which exposes a portion of the support or an underlying second conductor that is non-solderable. An electrically conductive bridge plate is soldered into electrically conductive engagement with the conductor at two distinct spaced positions along the plate, the two positions being located on opposite sides of the discontinuity. The bridge plate may be arched between the two positions if desired, and the panel as a whole may comprise an electrical resistance heating panel.

Abstract: A thermal display comprising an array of semiconductor heater mesas having a larger cross-sectional area at the display surface than at the support surface. The preferred structure is in the shape of a truncated, inverted pyramid. The novel method includes forming the inverted heater elements by etching trenches in one surface of the semiconductor substrate and forming the heater mesas at the opposite surface, with the trenches defining the individual mesas.

Abstract: The disclosure relates to a ceramic heating device in the form of a cylindrical shape comprising a burnt cylindrical support core of heat-resistant ceramics, a ceramic element disposed around said support core, said element comprising (i) a burnt sheet of heat-resistant ceramics; (ii) a heat-generating resistor pattern, said pattern being hermetically sealed between said sheet; and (iii) a pair of exposed terminals provided onto said sheet and said core, said terminal being connected to said pattern and adapted to be coupled to power leads such that electric power is then applied to said pattern.

Abstract: A device for heat fixation comprises a heating member comprising a heat resistant insulating support, a heat generating member provided on the support and a thin film of heat resistance, low surface tension and low friction coefficient overlying the heat generating member.

Abstract: A plastic laminate form of heating panel incorporating a layer of a semiconductive carbonaceous pyropolymer, consisting of carbon and hydrogen on a high surface area refractory inorganic oxide support, with the conductive pyropolymer positioned to at least one side of at least one laminate layer and a reflective metallic layer on the other side thereof such that radiant heat is controlled and directed outwardly in a desired manner to minimize energy being wasted by a "rearward" flow.

Abstract: An improved radiant heater has a metal heating plate formed with at least one bulged portion surrounded by a flat transversely extending peripheral flange. Each of the bulged portions has a concave curved inner surface and a convex curved outer heat radiating surface. At least the entire concave surface of each bulged portion is covered with a coating of vitrified enamel and a printed circuit electric heating element is deposited on the enamel coating. A peripheral transition area is provided adjacent the intersection of each of the bulged portions and its surrounding flange. The transition areas are so shaped as to impart stress upon thermal deformation of the heating plate such that the enamel coating is compressed thereby increasing the dielectric resistance of the coating.

Abstract: A heating panel safety system has electrodes on opposite sides of the heating panel which supply conductive material. A first lead wire has ends connected to spaced terminals on a first electrode, and a second lead wire has ends connected to spaced terminals on a second lead wire. Turns in the lead wires are coupled via a core with a turn in a relay energizing wire. Normally closed circuit breaker contacts of the relay are opened when the relay is energized by a bias current in one of the lead wires, such as caused by a discontinuity in an electrode. Opening of the circuit breakers stops flow of current from a power source to the lead wires.

Abstract: A laminated electrically heatable window has a transparent electrically conductive layer embedded in the window to act as a sheet resistor, and conductive bus bars embedded in the window in contact with the resistive layer. A portion of each bus bar extends outside an edge of the window to a terminal connection for making electrical contact with a harness cable leading to an electric current source such as an automobile alternator. Each terminal connection comprises separate electrical contacts on the ends of the bus bar and the cable harness for forming a cooperating pin and socket connection normal to the bus bar. The electrical contacts are pressure fitted together and hermetically sealed from end-to-end in an electrically insulating, protective sleeve.

Abstract: A metallic strap includes two feet soldered to a conductive coating forming part of a heating grid on a glass substrate and, joining those feet, a bridge portion integral with the feet to which a conductor may be affixed for supply of current to the grid. The bridge portion is notched, slotted or perforated to reduce the stresses which differences in thermally induced expansion or contraction between the strap and substrate can impose on the attachment of the strap to the coating.

Abstract: A windshield heating device for a motor vehicle having a windshield with an upper portion normally within the driver's field of vision and a lower portion normally not within the driver's field of vision is disclosed. A plurality of electrically conductive grid lines are deposited on the lower portion of the windshield. The grid lines are bonded to the windshield and are formed of a material which heats up when an electrical current is passed therethrough. An instrument panel of the motor vehicle is mounted adjacent the lower portion of the windshield. The instrument panel has openings therein in juxtaposition with the grid lines on the windshield. Operation of a blower motor directs air over the grid lines when they are heated to cause a moving current of heated air to pass from the lower portion of the windshield to its upper portion. This action defogs and/or defrosts the windshield.

Abstract: An electrical heating unit having a flat utensil-supporting plate of glass-ceramic or other electrical non-conductive material. On the underside of this plate are bonded multiple coil electrical resistance film heaters arranged in a generally closed loop. Each coil or loop is of substantially equal length to have about the same watts density and provide a generally uniform temperature distribution over the top surface of the heating unit.

Abstract: An electrically conductive composition comprises a particulate, homogeneous blend of:A. about 60% to about 98% by weight of graphite;B. about 1.5% to about 20% by weight of manganese dioxide; andC. about 0.5% to about 20% by weight of zinc oxide, based on total weight of said blend. These compositions are suitable for the manufacture of coating compositions, heating elements and structures which are useful where radiant, conductive, or convective heating is required, and for other applications which utilize the sheet and volumetric electrical conductivity properties of the formulations made therefrom.

Abstract: A monolithic electrical resistance heater device is produced from placing a semiconducting coating of carbonaceous pyropolymer on the surfaces of a rigid "honeycomb type" of ceramic substrate and connecting electrodes to spaced, opposing portions thereof. The carbonaceous coating, or layer, is formed from heating an organic pyrolyzable substance in contact with the substrate surfaces at a temperature above about 400.degree. C.

Abstract: A defogging and defrosting rear window pane for motor vehicles has a plurality of spaced heating elements embedded therein. A relatively short metallic collector having a circular segment configuration is provided in each peripheral side of the window pane at opposite margins thereof. The central heating element extends between the collectors in a rectilinear path. Additional heating elements above and below the central element have a rectilinear central portion parallel to the central element and are connected to the collectors by end portions converging on the respective collectors. The respective collectors have an appendix extending outwardly beyond the window weatherstripping to serve as a terminal for connection to a power source.

Abstract: A thermal print head produced by a multilayer process is disclosed. Six of the seven bar-segments of the figure "8" produced by resistive deposits are bounded on the outside by conductive deposits and on the inside by the internal areas of the figure "8" while the seventh is bounded by the internal areas of the figure "8". The peripheral segments are heated selectively by conduction between selected bar-segments and associated internal areas at a particular time while the internal areas are energized to heat the central segment at another time. Each internal area has a single electrical connection to the external switching circuitry.

Abstract: A latching circuit is used in a thermal printhead matrix. The heater circuit in each mesa or element of the matrix, once energized by input logic signals, is thereafter independent of changes in the input logic signal levels and remains energized until the supply voltage is removed. This permits turning on the individual mesas in a matrix fashion thereby substantially reducing the number of input leads required to control the matrix.

Abstract: An electrically heated window system having at least two independently heatable zones wherein each zone includes its own independent resistance heating element which provides a path for the flow of electric current. A selected region in one of the zones includes a secondary heating component which produces a relatively high temperature in this region of the zone which controls a thermostat in thermal contact therewith. The thermostat initially connects an electrical potential to the one zone and then automatically cycles the electrical potential between the two zones in accordance with the rise and fall of the temperature in said selected region.

Abstract: A monolithic electrical resistance heater element is produced from mixing particles of a conductive carbonaceous pyropolymer that have been deposited on a refractory metal oxide with a heat unifiable ceramic, such as alumina, cordierite, spodumene, etc., and then forming a resulting rigid "honeycomb type" of semiconductive ceramic substrate. The carbonaceous pyropolymer particles are preferably formed from heating an organic pyrolyzable substance in contact with alumina particles, or other metal oxide particulates, at a temperature above about 400.degree. C.

Abstract: An integrated semiconductor circuit has a portion thereof divided into a plurality of air isolated mesas which constitute a heater element array. A heater transistor formed within each mesa is selectively turned on in response to logic signals to heat one mesa of the array. By selectively heating the correct mesas, an area of the mesa array corresponding to a desired character is heated. Thermally sensitive material on which a dynamic display is formed or on which a permanent display is printed is in thermal contact with the material of the heater element array. Also formed within each mesa is its corresponding driver transistor.

Abstract: An electric connector for electrically heatable window panes including a tin-plated platelet solderable to a bus conductor having a tongue integral with the platelet bent at an angle with the platelet and adapted to be connected to the feed wire, wherein the area of the soldered joint is extended to both sides of the axis of the bend.

Abstract: An electrical heating unit of the integral element type, comprising an electrical heating element indirectly bonded to a supporting beta quartz-zinc petalite glass-ceramic plate is described. A semicrystalline zinc aluminosilicate coating is provided between the glass-ceramic plate and the heating element, to improve the adherence and stabilize the resistance of the element and to protect the plate from deterioration during and subsequent to the bonding of the integral heating element to the unit.

Abstract: An electrical heating unit of the integral element type, comprising an electrical heating element indirectly bonded to a supporting lithium aluminosilicate glass-ceramic plate, is described. The glass-ceramic plate is provided with a semicrystalline zinc aluminosilicate coating which protects it from the harmful effects of interaction with subsequently applied ceramic and metallic compositions making up the heating element and associated components.

Abstract: A laminated glass-plastic glazing unit suitable for aircraft is disclosed. The unit comprises a pair of sheets of rigid transparent material such as glass and an interlayer of thermoplastic material that is susceptible to crack at low temperatures and that has a higher coefficient of thermal expansion than the sheets of rigid transparent material. Electrical resistance material preferably in the form of thin metal wire, is embedded within the interlayer and disposed locally in areas along a pair of opposite marginal edges of the interlayer and electrically energized to heat the interlayer portion adjacent thereto sufficiently to overcome the tendency of the interlayer to pull chips from the marginal portion of one or both of the rigid sheets when the unit is subjected to extremely low temperature conditions in a high-flying aircraft.

Abstract: An electrical heating unit of the integral element type, comprising a platinum film heating element bonded to a supporting ceramic plate, wherein the platinum film heating element is electrically stabilized and physically protected by a lead titanate overglaze, is described.

Abstract: A wood veneer laminate form of heating panel incorporates an internal layer of a semiconductive carbonaceous pyropolymer, consisting of carbon and hydrogen on a high surface area refractory inorganic oxide support, to provide electrical resistance radiant heating. The carbonaceous pyropolymer in powder form can be incorporated with the glue line between veneer or core stock layers or mixed with a resin to be impregnated into a glass-cloth, or other support material, to form a conductive prepreg sheet which can be placed between wood veneer layers.

Abstract: The thermal print head disclosed herein comprises resistive heating elements deposited on mesas of glass glaze over an aluminum oxide substrate for more efficient marking of thermally sensitive recording material. After the mesas are formed in the glass glaze by etching, resistive and conductive materials are deposited over the mesas by thin film techniques. Thereafter, the raised heater elements and conductors are delineated chemically, then heat-treated to upwardly adjust the resistance of and to grow a protective oxide over the individual heater elements. Since the resistance value of the heater elements can be controllably increased as a function of the temperature and time of heat treatment, external trimming resistors are eliminated.

Abstract: A removably mountable electrothermal print head for writing dots-matrix characters while moving along a thermosensitive recording medium and a mounting for the hand or a movable carriage of a printer, the head comprises a plurality of electrically energizable resistive printing elements coated on a support; the outer surface of said elements is partly cylindrical with the generatrices in parallel relation with a common direction which is transversal with respect to the printing line of the recording medium. The print head is positioned with respect to the recording medium with the part-cylindrical outer surface of the resistive printing elements in tangential relation with the recording medium. The printing head is positioned on and removably fixed to the carriage by a manually actuatable latch.

Abstract: A method and apparatus for a thermal printer head which uses individual heater elements as switching devices is disclosed. The printer head consists of an array of individual resistors each capable of causing a dot to print on thermally sensitive paper. The use of heater elements as switches reduces the total number of lead outs required for the printer head. A system that uses such a thermal printer head is also disclosed. The individual resistor heater elements have a voltage-current switching characteristic which enables them to be used as switching devices in addition to their function as heating elements.

Abstract: An array of elongated thermal printing elements which may be selectively energized through suitable electrodes connected to the long dimension of the thermal printing elements to thermally print numeric characters or other information.

Abstract: A thermal printer comprised of a shift register, a line buffer and a plurality of printheads in heat-transfer relationship with a heat-sensitive record medium. The shift register and line buffer are comprised of a plurality of stages or modules with each module having an amorphous semiconductor heating element that exhibits current controlled negative differential resistance in heat-transfer proximity to a heat-gated amorphous semiconductor threshold switch which has a V-I characteristic which is strongly temperature dependent. The printheads are comprised of the amorphous semiconductor heating elements. Data is stored in the shift register by means of a video data signal and two oppositely phased clock signals of an amplitude that will only bias a heated threshold switch to conduction, with transfer of data to the line buffer being achieved in a parallel format by a third properly phased clock signal.

Abstract: An electrical cooking unit comprising a cover on which cooking can take place, heating resistors in the form of PTC resistor elements being distributed over the underside of the cover, the PTC resistor elements being made of a PTC resistor material, the resistance of which varies as a step function of temperature, and being distributed over the underside of the cover to provide zones on the cover of varying energy density and/or varying step temperature of the PTC resistors.

Abstract: A heater on metal composite unit. A strip of metal has a stripe of an electrically insulative and thermally conductive synthetic resin material bonded to one surface along the length thereof. At least one stripe of an electrically conductive material, having a width less than the width of the insulative stripe, is bonded to the surface of the insulative stripe along the length thereof. A strip of electrical resistance material at least partially overlies the stripes of both the conductive and insulative materials thereby providing a path of electrical resistance material from the conductive stripe transversely across a portion of the width of the insulative stripe whereby when electrical current flows through the electrical resistance material it will supply heat to the metal strip. Apparatus and a process for fabricating these composite units are also disclosed.

Abstract: A frangible panel having an electrically-energizable layer carried in an area thereof for heating the panel and main circuit means for supplying electrical power to the layer is provided with circuit breaker means operable to interrupt electrical power to the layer upon breakage of the panel. The circuit breaker means includes a fusible link connected in series with the layer and a solid-state control device connected in the main circuit in parallel with the layer. The solid-state device has a control gate which is connected to a sensing circuit surrounding the electrically-energizable layer and which is connected in the main circuit to render the solid-state control device non-conductive as long as the sensing strip is continuous and to render the solid-state control device conductive when the sensing circuit is broken. Thus, the solid-state control device connects the fusible link to ground and causes the link to blow, thereby interrupting power to the electrically-energized layer.

Abstract: After the mesas are formed in the glass glaze over an aluminum oxide substrate by etching, and before resistive and conductive materials are deposited over the mesas by thin film techniques, an aluminum oxide underlayer is applied. The aluminum oxide underlayer provides controlled etching of the raised heater elements and conductors to prevent undesirable additional erosion of the glass glaze mesas.

Abstract: An electrically heated laminate including a flexible heater fabric, wherein the heater fabric comprises a woven glass fabric having a layer in contact with electrodes of an electrically conductive mixture comprising a vinylidene chloride polymer and carbon to provide the desired watt density and an outer coating of a vapor barrier of a vinylidene chloride polymer. A fabric softener layer may also be provided between the glass fabric and the conductive coating to impart greater flexibility to the heater fabric.

Abstract: An electrical resistance heater on a metal substrate. Bonded to a surface of the substrate is an insulating layer of a cured polyimide or polyamide-imide resin. A second layer of a cured polyimide or polyamide-imide resin having dispersed therein at least approximately 60% by weight of graphite flakes is bonded to the insulating layer. Intermediate and bonded to a portion of the insulating layer and an opposing portion of the second layer is an electrically conductive stripe which provides a high conductivity path to interconnect the second layer to an external electrical circuit. The stripe is formed from a cured polyimide or polyamide-imide resin having dispersed therein flakes of a conductive metal. The layers are flexible and the second layer and stripe have electrical conductivities which are not substantially degraded during operation at temperatures of at least 200.degree.C. for extended periods of time.

Abstract: A dielectric substrate is provided with a thin narrow heater strip of multi-layer metallic films of noble metals such as platinum and gold. The film heater is bonded to the substrate and it has terminal means comprising a silver film electrode that is spaced away from the film heater. A metal oxide diffusion barrier such as a tin oxide film bridges the gap between the film heater and the silver electrode and retards the electromigration and mass flow between the film heater and the electrode.

Abstract: The thermal print head comprises a substrate, a semiconductor wafer fabricated thereover, a plurality of junctions formed on the semiconductor wafer, and electrodes to supply an inverse current to the junctions. The junctions are arranged so as to correspond to the pattern of the symbol, such as letters, to be printed. Each of the junctions is used as a heating element. Heat is evolved at the junction when the inverse current flows through the potential barrier which is formed at the junction. The heat evolved is used for the heating element.