Abstract: A flat, normally horizontal electric resistance blanket heater comprising a thin, fragile elongate resistance element on one surface of and carried by a thin, flexible sheet of dielectric material, a thin, flat resilient and flexible reinforcing strate of dimensionally stable material retained adjacent the other surface of the film to permit flexure of the heater and without dimensional distortion of the film and element and a flexible envelope encapsulating the sheet element and strate.The heater also includes temperature responsive switching means responsive to the temperature of heated portions of the heater and in temperature insulated relationship from a portion of the heater where the element connects with power supply lines and which creates a portion in the heater of increased mass and heat storing capacity.

Abstract: A warming room whose flexible, electric blanket-like wall or walls, floor and ceiling generate surface heat to provide uniform warmth in the area which they enclose. Portions of the warming room comprise one or more warming walls or barriers to increase the temperature of an indoor area and enhance the comfort of its occupants. Using the invention, people lower thermostat settings in portions of rooms, offices or other buildings which are not occupied while they occupy the warmer area within the warming room or adjacent to a warming barrier or enclosure made of warming barriers.

Abstract: An electrical heating apparatus, and particularly a bedcover preferably in the form of a blanket, protected against an overheating condition and in which electrical current flow through a heating element is controlled by a pair of gate controlled bidirectional semiconductor switches electrically connected to one another in series and in front-to-front orientation. The gates of the semiconductor switches are connected through a temperature sensitive capacitor which triggers the semiconductor switches from a conductive to a nonconductive state in response to the sensing of an overheating condition.

Abstract: A heating cable having spaced helically wound conductor wires separated by a layer of positive temperature coefficient material which functions as a self-limiting heating element. At least one of the conductor wires is helically disposed on a stranded core of insulating fibers which have been coated and impregnated with conductive carbon.

Abstract: A thin, flat, multi-laminate resistance heater structure including a pair of spaced laminates of dielectric material with opposing inner surfaces, an elongate resistance element arranged between and extending throughout the major surface areas of said opposing surfaces, bonding material about the element and between the element and between the laminates and a filler in the bonding material comprising a multiplicity of strong dimensionally stable particulate components of a dielectric material having a lower dielectric constant than the bonding material.

Abstract: In an electric bedcover of a type wherein a safety thermostat having a bimetallic element is adapted to deenergize a heater when the bimetallic element is heated sufficiently, as when an overheated condition occurs, an elongated flexible sensor of a type comprising a pair of conductors spaced from each other by a layer of material having a negative temperature coefficient of resistance is adapted to influence the bimetallic element through a resistor, which is mounted for heat dissipation to the bimetallic element, and a first circuit branch comprising the resistor, the conductors, and the layer between the conductors, in series with each other, is connected so as to maintain the conductors at different potentials when the heater operates, and so as to conduct sufficient current to cause the resistor to conduct sufficient heat to cause the bimetallic element to open the contacts when some part of the layer between the conductors is heated so as to act as an electrical conductor having a low impedance rather t

Abstract: A heating circuit for an electric blanket or the like comprises a cable (1) formed from a heater conductor (2) separated from a sensor conductor (3) by temperature sensitive material (4) and two series resistor-diode pairs (R1-D1 and R2-D2) each connected between ends of the conductors (2, 3) so that each pair conducts in series with the impedance (Z) of the material (4) during respective half-cycles of an AC mains supply, the arrangement being such that general overheating of the cable (1) or localized overheating anywhere along its length reduces the impedance (Z), (possibly to zero if the material (4) melts), such that the current through one or both of the resistors (R1, R2) heats the resistor(s) and blows a thermal fuse (F) to terminate heating. The thermal fuse (F) may be replaced by a resettable interruption element, namely a self-regulating PTC resistive element.

Abstract: A system comprising a heat generating load, a power control element for controlling power supply to the heat generating load, a temperature detecting circuit for producing an ON signal when the temperature of the load detected by a temperature sensor is lower than a set temperature and an OFF signal when the temperature has reached the set temperature, and a control circuit for feeding on ON or OFF signal to the power control element in response to the signal from the temperature detecting circuit. The control circuit includes a hysteresis control circuit which, once the temperature detecting circuit detects that the temperature has reached the set temperature, permits the power control element to receive OFF signals for a suitable period of time even after the temperature has subsequently lowered to a level at which the signal from the temperature detecting circuit changes to an ON signal.

Abstract: The present invention relates to a battery powered thermal garment that is provided with a battery recharging circuit that is designed to recharge a battery package associated with said thermal garment approximately 30-40 times as fast as conventional recharging devices. In addition, the recharging circuit of the present invention is provided with a separate and direct power source for energizing the heating elements within said garment independently of said battery package. With respect to the recharging circuit, a transformer is provided for stepping down a AC voltage source and the transformer includes a dual tap, one for providing the independent power source to the garment and the other providing a recharging current. The recharging current is rectified and then directed through a silicon control rectifier to the battery package for recharging.

Abstract: A temperature control system for electric surface heater of piled layers of a heating element across which a commercial AC source current is fed and a thermosensitive electrode opposing the element through thermosensitive element showing negative impedance characteristics with temperature rise. In the system, an AC signal voltage different from the source current is applied between the heating element and the thermosensitive electrode, and excessive variations in the signal voltage responsive to the negative impedance of the thermosensitive element is detected to disconnect or connect the heating element and the source.

Abstract: A flat normally horizontal electric resistance blanket heater comprising a thin, fragile elongate resistance element established on one surface of and carried by a thin, flexible film of dielectric material, a thin, flat resilient and flexible reinforcing strate of dimensionally stable material retained adjacent the other surface of the film to allow for controlled flexure of the heater and prevent dimensional distortion of the film and element and an envelope of flexible dielectric plastic film encapsulating the film, element and strate.The heater also includes temperature responsive switching means responsive to the temperature of heated portions of the heater and in temperature insulated relationship from a portion of the heater where the element connects with power supply lines and which creates a portion in the heater of greater mass and heat storing capacity.

Abstract: A heating circuit, in particular for electric blankets or pads, comprises a first, heating conductor and a second conductor separated by a material which has an impedance that falls with increasing temperature and/or which will melt in the event of overheating to allow contact between the two conductors. A half-wave rectifier and a thermally-operative circuit interruption means are connected in series with the heating conductor across an AC supply. A resistor is electrically connected to the second conductor such that the resistance and the impedance of said material are connected in series across the supply. The resistor is thermally coupled to the circuit interruption means whereby, in the event of overheating of said material, the drop in the impedance of the material to a reduced or zero value will cause the current through the resistor to increase to heat the resistor, which causes the circuit interruption means to disconnect the circuit from the supply.

Abstract: A heating circuit, in particular for an electric blanket or pad, comprises an elongate heating conductor and switch connected in series between input terminals for connection to an AC supply. Switch control is operative to close the switch to cause current to flow through the heating conductor. The circuit further comprises a sensor conductor coextensive with the heating conductor, and a temperature sensitive resistance coextensive with the heating and sensor conductors and having an impedance that falls with increasing temperature. A resistor is connected in series with the sensor conductor such that a current dependent on the impedance of the temperature sensitive resistance flows through the resistor, whereby the voltage across the resistor varies with said impedance. Voltage sensing structure is responsive to the voltage across the resistor reaching a predetermined value to inhibit operation of the switch control, thereby to provide normal and/or overtemperature control.

Abstract: The heating element includes a flexible graphite fiber-loaded impregnated paper saturated with a binder to ensure and maintain intimate electrical contact between the graphite fibers. In one form, two segments of the graphite fiber-loaded paper are coupled in series through a common bus bar and are electrically coupled to an SCR control circuit using a thermistor as a temperature responsive device. The graphite fiber-loaded paper with thermistor and electrical leads are encapsulated between cover sheets to provide an extremely thin highly flexible drapable therapeutic heating pad. Another form of heating pad includes providing the graphite fiber-loaded paper in the form of strips bonded to a plastic substrate. Electrical leads are attached and the substrate is enclosed by a cover sheet to provide a highly flexible heating pad. Two discrete methods of forming the latter heating pad are disclosed including silk screening and die pressing operations.

Abstract: A hand warmer, particularly for simple therapeutic treatment or pain alleviation for the hands of arthritics, the warmer having the general configuration of a muff accommodating both hands of the user, the muff having a heated core which can be gently or firmly grasped by the user, inside an outer envelope of soft cloth or fur-like material which retains the heat, the core also having a covering of soft thermal material over a safety sheath and heat-distributive padding to prevent accidental contact with wiring or hot spots in the core.

Abstract: A heating circuit comprises input terminals for connection to an AC supply, an elongate heating conductor and a switch connected in series between the input terminals, a switch control operative to close the switch to cause AC current to flow from the supply through the heating conductor, an elongate sensor conductor spaced from the heating conductor, and a temperature sensitive element disposed between the heating and sensor conductors and responsive to over-heating at any position along the length of the heating conductor to drop substantially in impedance at that position to connect the sensor conductor to the potential of the heating conductor at that position.

Abstract: An electrical heating apparatus such as an electrically heated bedcover protected against an overheating condition by an overheat protective circuit which utilizes a pair of solid state switching devices in the heating element circuit. The solid state switching devices are so connected that should one switching device fail in a shorted or closed mode, a second switching device will be in the circuit to control the heating element and provide normal protection against an overheating condition. The solid state switching devices are employed in a manner which permits the use of relatively small light weight temperature sensors in the form of positive temperature coefficient devices such as PTC resistors, which avoids the need for using relatively bulky bimetallic thermostatic switches as are conventionally employed for sensing overheating conditions.

Abstract: A sheet-like thin flexible heat-emitting surface layer and a coextensive thin flexible serpentine heat-sensing layer are overlayed by thin flexible synthetic plastic sheets which are sealed peripherally. Lead wires from an electrical plug to the heat-emitting layer are interrupted by a controller which is operated by current flowing through the heat sensing layer. Increased heat changes conductivity and current in the heat sensing layer, causing the controller to interrupt or reduce power to the heat-emitting layer.

Abstract: An electric resistance heater engageable with work to be heated including a work-engaging heater structure of minor thermal mass per unit area and including an elongate primary heating element arranged to establish high watt density throughout said heater structure, a power supply, a temperature control means between and connected with the primary heating element and the power supply; said temperature control means including a work engaging body of greater thermal mass per unit area than the heater structure and carried by said heater structure in spaced relationship with the primary heating element, a normally closed thermal responsive switching device within the body and operable to open when the temperature of the body is heated by heat conducted from the work to a predetermined operating temperature, an elongate secondary heating element arranged in the body to delivery sufficient heat into the body to normally maintain the temperature thereof at a temperature slightly below said operating temperature whe

Abstract: A cooling and heating blanket comprising a blanket enclosure with heating means including a plurality of flexible elements positioned within the enclosure for being electrically energized for supplying heat to the enclosure, such that the enclosure may be retained above room temperature, and cooling means including a plurality of flexible fluid carrying conduits positioned within the enclosure through which a heat transfer fluid can flow, such that the enclosure may be retained below room temperature. Control means including an electric motor and a pump driven thereby located remotely relative to the enclosure is provided with flexible conduit means connecting the enclosure and the cooling means, and regulating means is operatively associated with the heating means and the cooling means.

Abstract: This disclosure pertains to a blanket having a plurality of portions of flexible heat pipes sandwiched between the outermost layers thereof. The portions of the flexible heat pipes disposed about the blanket provide a uniform heating or cooling pattern therein. The ends of the flexible heat pipes that are free from the blanket are thermally coupled to a combination heating and cooling system. When utilizing the heating system, the flexible heat pipes provide elevated temperatures at the blanket surfaces. When utilizing the cooling system, the flexible heat pipes provide lower than ambient temperatures at the blanket surfaces.

Abstract: A quilt shaped to fit about the top surface, sides and bottom edges of a mattress. The quilt is formed of insulated cotton material with a continuous electrical heating element embedded in the top sheet which is covered by a waterproof plastic cover sheet bonded to the top sheet. The heating element is externally connected to a control box for regulating the flow of the electricity to the heating element.

Abstract: An electric blanket shell is composed of first and second-needled textile fabrics with a yarn layer disposed in at least one of the needled fabrics. The yarn layer has a plurality of first planar yarns extending generally in a first planar direction. A heat-fusible component is disposed in at least one of the needled fabrics. A plurality of small, discrete sonically or ultra-sonically-produced fusion bonds, spaced from each other, link the needled fabrics to form a blanket shell. The fusion bonds form a series of patterns across a planar dimension of the blanket shell and the patterns define a series of channels, for receiving heating wires, between the needled fabrics. The patterns of fusion bonds are disposed in a direction traverse to the direction of the first planar yarns. The fusion bonds of any one pattern do not engage more than about 50% of the first planar yarns and overlaps of fusion-bond patterns are substantially avoided.

Abstract: An electric blanket control circuit is provided which includes an overheat protection circuit to detect an overheat condition as well as a fail-safe testing circuit to assure that the electrical components in said overheat protection circuit are properly functioning. A simulation circuit is provided to electrically simulate an overheat condition in the blanket. An on-off switch is provided which will consecutively activate the overheat simulation circuit and then the fail-safe testing circuit so that said circuits are activated each time the electric blanket is turned off by the user.

Abstract: An electric blanket assembly having a blanket whose heating elements are supplied from a low voltage supply source and a control circuit assembly adapted both to regulate the heating of the blanket and to disconnect the supply source from the heating elements under conditions of malfunction of the assembly. The control circuit includes temperature sensitive elements suitably located in the blanket and associated circuitry arranged to generate a control voltage which is selectable and reference voltage generating means which is also selectable. The control circuit also includes means to compare the control voltage and the reference voltage and to control current flow through the heating elements.

Abstract: An electric blanket shell is composed of first and second-needled textile fabrics with a yarn layer disposed in at least one of the needled fabrics. The yarn layer has a plurality of first planar yarns extending generally in a first planar direction. A heat-fusible component is disposed in at least one of the needled fabrics. A plurality of small, discrete sonically or ultra-sonically-produced fusion bonds, spaced from each other, link the needled fabrics to form a blanket shell. The fusion bonds form a series of patterns across a planar dimension of the blanket shell and the patterns define a series of channels, for receiving heating wires, between the needled fabrics. The patterns of fusion bonds are disposed in a direction transverse to the direction of the first planar yarns. The fusion bonds of any one pattern do not engage more than about 50% of the first planar yarns and overlaps of fusion-bond patterns are substantially avoided.

Abstract: An improved heating device such as a heating pad comprising a fabric base and insulated resistance wire mounted in said pad, preferably in a backward and forward sinuous pattern, at least one thermostat connected in series with the resistance wire element at both ends by means of lead wires of a low resistance metal such as copper, each thermostat being positioned intimately with a span or straight portion forming part of a sinuous loop of resistance wire, a switch connected in series with the resistance wire, and a plurality of bars of a metal such as lead mounted in the pad. In an improved embodiment the insulation on the resistance wire is formed of a plastic material able to withstand the elevated temperatures attained by the resistance wire during operation.