Abstract: A heated tube with a electric heater comprising a braid structure of bare strands of resistance wire connected in an arrangement to form a number of resistance circuits in parallel in a zone formed between exposed core portions of an electrical feeder line. The electric heater is braided directly on a tube, or is braided in a flat shape and then wound in a large spiral around a tube and a feeder line with cores having exposed portions arranged along the tube. When power is supplied to the feeder line, the electric heater generates heat at each zone and a fluid flowing through the heated tube is uniformly heated.

Abstract: A continuous temperature sensing cable formed of a polymer containing conductive and semi-conductive fillers such as polyethylene with carbon black, powdered metals and metal oxides. The composition is extruded over a pair of elongated substantially parallel conductors which are spaced apart along the longitudinal length of the cable. The conductors are single-endedly connected to a control/alarm device for monitoring the continuous length of the temperature sensing cable. A critical voltage is applied single-endedly to the conductors and serially connected to an audible alarm to detect tunneling conduction when operated at a temperature near the melt temperature of the composition whereat the composition exhibits a negative temperature coefficient (NTC).

Abstract: An elongate resistive sensor useful as an element of a pneumatic manifold failure detecting and locating system. A sensing loop is based on a coaxial cable having a core of known resistance per unit length. A eutectic salt impregnated insulant separates the core and sheath but has a temperature breakdown characteristic which provides the sensing function. Upon a pneumatic manifold failure, the sensing cable is heated, the eutectic salt insulator breaks down, a core-to-sheath short occurs, and currents in the sensing cable are substantially altered as a result. The cable is connected as a loop, and differential currents into the ends of the loop are detected and processed to determine the position of the short. Terminating resistors are associated with connectors which connect multiple cable sections into a single loop, and the terminating impedance is further sensed to determine an open circuit condition at any connector.

Abstract: An electric heater comprises a braid construction of a plurality of strands having electric resistance, thereby the strands are heated due to a Joule heat when a current flows therethrough. The strands are braided with a core wire of tube or without cores. These strands are placed in two core wires dielectrically insulated, which core wires have exposed portions formed therein in a shape of semi-circle or arc-like at a regular interval mutually. The core wires are covered with an insulator laid thereon and an electric heating element is wound around the insulator covering in a large spiral. A C-shaped fixing piece made of metal is used to be adapted on the exposed portions of the core wires. Then the opening of the C shape of the fixing piece is pressed toward each other to close it. Claws, formed on the inner face of the fixing piece, grip firmly the strands of the heater element to the core wires.

Abstract: A resistance stack for terminating a data bus cable includes a stack of resistor chips, each having two conductively plated through holes. The resistance elements are kept in alignment and electrically connected to leads of the data bus cable by elongated members extending through the through holes. The elongated members may be discrete conductive rods, or soldered and pre-tinned leads of the cable. To facilitate assembly, solder preforms are provided between each of the resistor chips. The resistance stack is enclosed in a package which includes a cylindrical shell, a cable clamp, a cable strain relief member, and an end cap including a track for accommodating extensions of the elongated members beyond the last resistor in the stack, thereby aligning the elongated members. The package may be both electrically shielded and environmentally sealed.

Abstract: An electronic device for conducting electric current has two contacting components at least one of which is a nonmetallic electronic contact in the form of a pultruded composite member made of a plurality of small generally circular cross section conductive fibers in a polymer matrix, the fibers being oriented in the matrix in a direction substantially parallel to the axial direction of the pultruded composite member and being continuous from one end of the member to the other to provide a plurality of electrical point contacts at each end of the member.

Abstract: A flexible induction heating coil comprising an elongated flexible core having proximal and distal ends. The core includes a plurality of core segments flexibly interconnected to make the core more flexible than the individual core segments. An elongated flexible inductor extends along the core.

Abstract: A non-metal controlled high resistance electric cable formed by wrapping a center strength member of insulating microporous polytetrafluoroethylene with a narrow strip of conductive carbon-filled microporous polytetrafluoroethylene and jacketing the wrapped strand with an insulating microporous polytetrafluorethylene or polyester jacket. The microporous polytetrafluorethylene layers are preferably sintered and the optional polyester layer is preferably fused.

Abstract: An electrostatic filter cable for an electrostatic filter system includes an internal electrical conductor formed of an electrically conductive plastic with a specific resistance in a range of substantially from 2 to 200 .OMEGA. mm.sup.2 /m. An insulation of cross-linked polyethylene is disposed on the internal electrical conductor. An outer conductive layer is disposed on the insulation. A copper shield is disposed on the outer conductive layer. An outer PVC jacket is disposed on the copper shield.

Abstract: An electrical resistance heater is provided which utilizes a copper-nickel alloy heating cable. This metallurgy heating cable is significantly less prone to failure due to localized overheating because the alloy has a low temperature coefficient of resistance. Used as a well heater, the heating cable permits heating of long segments of subterranean earth formation with a power supply of 400 to 1200 volts.

Abstract: An ignition cable having a resistance wire helically wound around a strength member to form a conductive core. A very thin adhesive layer is applied over the conductive core and is overlaid with a semi-conductive layer of a cross-linked thermosetting material. The cross-linked thermosetting material is extruded over the adhesive layer to form a smooth surface. A layer of insulating material and a protective jacket are applied over the insulating layer. A braid may be added intermediate the insulating layer and the jacket to increase the mechanical strength of the ignition cable.

Abstract: A high-tension resistance cable capable of maintaining a distributed capacitance not greater than 80 pF/m while having an outer diameter not greater than 5 mm includes a central resistance conductor which is no more than 0.8 mm in diameter. In one embodiment, the resistance is formed of a reinforcement core, a ferrite core layer, and a metal winding layer. In the metal winding layer, wires, having an outer diameter of 0.04 to 0.045 mm, are wound at a density of 91-115 times per centimeter around the ferrite core layer.

Abstract: The end portion of a wire wound noise preventing resistance cable in which a resistance wire is transversely wound around a core formed from an elastomeric compound is terminated such that the resistance wire is fully embedded in the core by applying heat and high pressure to the leading end that remains exposed after the cable is cut and the end portion thereof is stripped of a covering layer. This construction of the end portion of the core prevents unraveling of the resistance wire and maintains a good electrical connection between the resistance wire and a metal terminal.

Abstract: PTC Devices and PTC compositions described herein comprise a blend of at least three carbon blacks as a particulate filler in a fluorinated polymer to achieve a substantial PTC effect and operability over a wide temperature range including temperatures prevailing in a steam environment. Two of the carbon blacks are selected to impart PTC effect to the composition. The third carbon black is selected to adjust the resistive properties of the composition into the range of commercial usage and to impart uniformity of the resistive properties within a given batch as well as from one batch of mix to the next.

Abstract: An ignition cable having a layer of semi-conductive cross-linkable polyolefin extruded over a nonmetallic strength member to form a conductive core. An insulating layer is extruded over the conductive core and overlaid with a braid of glass yarn. A final layer of insulating material is applied over the braid of glass yarn to provide an external jacket. In an alternate embodiment, the braid of glass yarn is omitted.

Abstract: Conductive polymer compositions based on polyvinylidene fluoride have improved properties when the polyvinylidene fluoride has a very regular structure which can be characterized by a low head-to-head content in the repeating units. The improved properties include electrical stability when contacted by organic fluids and/or when maintained at elevated temperatures in air. Such compositions which exhibit PTC behavior are particularly useful in the form of self-limiting heaters which are immersed in organic fluids, especially flexible strip heaters for heating diesel fuel before it passes through a fuel filter.

Abstract: In-situ vitrification of soil is initiated by placing a cord of dielectric material impregnated with conductive material in thermally-conductive contact with the soil, and energizing the cord with an electric current for heating the cord and starting the vitrification process.

Abstract: An engine ignition cable in which carbon fiber is mixed with conductive rubber or synthetic resin, to provide a conductive portion in which the resistance value is readily adjusted. The conductive element of the cable is made of carbon fiber of polyacrylo nitrile type. The conductive element is coated with an electro-conductive layer comprising a mixture of polyacrylo nitrile type carbon fiber powder and conductive rubber or synthetic resin mixed in accordance with a predetermined ratio to achieve a predetermined resistance value.

Abstract: A heating unit includes a heatable surface. At least a region of the heatable surface is coated or otherwise provided with a layer incorporating a thermochromic material in sufficient quantity to influence the perceived color of the layer. The thermochromic material exhibits an absorption edge wavelength which changes reversibly with temperature in the range of from 20.degree. C. to at least 400.degree. C. The absorption edge wavelength is at least 540 nm at 20.degree. C. and progressively increases to at most 700 nm at 400.degree. C. Such a heating unit is able to provide a visual indication of whether or not the heatable surface is still hot once the power has been switched off. Useful thermochromic materials include Cd(S.sub.1-x Se.sub.x) and (Zn.sub.1-y Mn.sub.y)O.

Abstract: A connecting element is provided comprising an electrical conductor and a conductive path of arranged carbon along the connecting element's entire connecting length. The conductive path can either be formed as an integral part of the electrical conductor or as a separate element which works in cooperation with the electrical conductor. The carbon is arranged in that the nuclear magnetic resonance of substantially all of the carbon atoms of the conductive path has a determined orientation. The carbon is arranged by way of the connecting element being passed through a magnetic dc field which orients the nuclear magnetic resonance of the carbon atoms with relation to that field.

Abstract: A high voltage cable having a wound conductor made by winding a metallic wire around a ferrite rubber covered reinforcing core, in which the ferrite rubber layer is additionally provided with conductive particles or fibers in order to improve noise suppression characteristics in the 30-200 MHz frequency range.

Abstract: The performance of a device under test is observed with and without the presence of controlled EMI fields. Voltage signals from the device under test are transmitted to an oscilloscope by overdamped conductors, a hybrid electrical/optical transmitter, a fiber optic cable, a receiver and a conductor cable. The overdamped conductors are transparent to the EMI fields and the current in those conductors is kept very small by the use of a very high input impedance in the transmitter. The hybrid transmitter may be an analog or a digital transmitter.

Abstract: A heated windshield wiper blade unit suitable for incorporation into existing windshield wiper assemblies. The unit comprises an elastic wiper blade, for example RTV rubber, and a flexible, fibrous carbon heating element disposed in the blade substantially along its entire length. The heating element contains a plurality of fibrous carbon strands coaxially surrounded by a heat shrunk polymeric tube. A live wire and a ground wire enter the blade and the heat shrunk polymeric tube at an intermediate point and extend through the tube to establish electrical contact with the respective first and second ends of the fibrous carbon strands. The wires preferably enter a side wall of the blade half way along its length and are insulated with a "tetrafluoroethylene polymer".

Abstract: A method for the manufacture of a high tension ignition cable wherein a tension member is passed through an extruder to form a settable plastic layer thereon. This extrusion takes place under conditions such that substantially no setting of the plastic layer occurs. Thereafter, winding a resistive conductor around the plastic layer to form a plurality of coils at least partially embedded in the layer. The coils are then coated with an insulation layer and a plastic layer is caused to set, thereby fixing the coils in position so that they do not move. The cable made by the foregoing process is also described.

Abstract: Diesel fuel is heated prior to filtration by passing it in thermal contact with a laminar heater immersed in the fuel. The heater has a resistance at room temperature of 0.30 to 0.75 ohm and comprises a PTC conductive polymer resistive heating element sandwiched between equispaced imperforate metal foil electrodes, particularly electrodeposited foil electrodes, coextensive with resistive heating element. The conductive polymer has a resistivity at room temperature of 20 to 2000 ohm - cm. The resistive element has a cross-sectional area in a plane parallel to the electrodes of 3 to 10 square inches and the electrodes have a microrough surface in direct physical contact with the conductive polymer.

Abstract: Disclosed are improved compositions useful in providing a conductive layer or coating on or within a conductor. The compositions contain elemental carbon and a polymeric matrix or binder. The improvement comprises employing a unique ground calcined, coal-based coke which approaches graphite in terms of its performance as a conductive additive or pigment but does not possess the disadvantages associated with the use of graphite.The unique coke employed in the compositions and methods of the present invention has a significant level of graphitic structure. This level of graphitization can be most easily recognized by utilizing x-ray powder diffraction. More specifically, when the value of E.sub.c or the inverse peak width (using the 002 peak) is measured for this material using Mo K.alpha. radiation (.lambda.=0.71 .ANG.), the value is in the range of about 27 to about 80, and preferably about 28 to about 75.

Abstract: A laser beam markable electric cable comprising an outer layer (13) enabling such marking to be performed, wherein said outer layer (13) is of a contrasting color relative to the color of an underlayer (14) which is absorbent at the laser beam wavelength. Said outer layer (13) is a thin layer which, during marking, is destroyed through its entire thickness by the laser beam (10) so as to reveal the underlayer (14).

Abstract: A winding of noise suppressing high tension resistive electrical wire is disclosed which comprises a reinforcing fiber cord bound by immersion in a low-viscosity liquid resin binder, an elastomeric coating layer formed on a surface of the fiber cord by application of a liquid rubber paint, a metallic resistive wire wound around the coating layer, and an insulating protective layer. The outer diameter of the winding may be less than about 7 mm.

Abstract: A flexible radiant tube heater is disclosed herein which is particularly useful in thermally stress-relieving the U-bend sections of the heat exchange tubes within nuclear steam generators. The apparatus generally comprises an elongated, flexible mandrel formed from a spring composed of a heat-resistant alloy, a flexible electrical resistance heating element wound around the mandrel spring, and a flexible insulating sleeve formed from braided alumina fibers disposed around the heating element for electrically insulating the heating element from both the metallic spring and the inner walls of the tube. A nosepiece assembly and an endpiece are disposed on the front and back ends of the spring, respectively. A flexible reinforcing member which may be a thin rod of Inconel.TM. is mounted to both the nosepiece assembly and the endpiece and disposed through the windings of the mandrel coil in order to lend more tensile and compressive strength to the mandrel coil.

Abstract: A heating element made of carbon, comprising a heating member including carbon powder and an insulating resin, the powder being kneaded with the resin, and a core member formed of an insulating material and having a higher fusing point than the heating member, the core member being disposed substantially centrally of the heating member.

Abstract: An ignition cable which applies ignition current from a power source to a spark plug of a spark ignited internal combustion engine while attenuating radio frequency currents. An inner elongated electrically conductive metallic core made of a high permeability material has an electrically semiconductive layer disposed thereabout and in intimate contact therewith. Insulation surrounds the semiconductive layer. Direct current is effectively and preferentially conducted by the inner core to provide ignition current, while high frequency currents are crowded by the skin effect into the semiconductive layer, where they are damped by the resistance thereof.

Abstract: To reduce resistance change due to heat and external force, the noise prevention high-voltage resistance wire comprises a non-metallic reinforcing core wire; a conductive composite including gaseous phase growth carbon fiber, in particular; and at least one insulating layer. The gaseous phase growth carbon fiber is obtained by thermal decomposition of hydrocarbon compound with a catalyzer within a reducing atmosphere. Further, the conductive composite further comprises preferably conductive carbon powder such as conductive carbon black or graphite.

Abstract: A high-voltage resistance wire for use in an engine ignition device has a resistive conductor, an insulating layer covering the resistive conductor, and a protctive sheath layer surrounding the insulating layer. The protective sheath layer is loosely fitted to the insulating layer so as to provide a gap of 0.1 mm or greater therebetween. The gap results in a small electrostatic capacitance between the innermost resistive conductor and the outermost protective which improves the ignitability of the resistance wire. Additionally, the protective sheath layer is formed by impregnating or coating silicone resin or fluororesin into or onto a tubular fiber braided body of glass or polyaramide fiber. The protective sheath has an improved flexibility and tearing strength from an end terminal.

Abstract: The resistivity/temperature characteristics of PTC conductive polymers which have little or no cross-linking can be modified by stretching. The rate at which resistivity rises with temperature is increased, and the peak resistivity is decreased; however, the decrease in peak resistivity is substantially smaller than that observed with PTC conductive polymers having a high degree of cross-linking. Therefore, heat-recoverable electrical devices, particularly for covering telephone and other cable splices, comprise (a) a layer of a PTC conductive polymer which has little or no cross-linking, (2) an adjacent heat-recoverable layer of a PTC or ZTC conductive polymer which has a relatively high level of cross-linking, and (3) electrodes which can be connected to a power supply so that current passes through the layers and causes recovery of the device; preferably an uncrosslinked PTC layer is sandwiched between two cross-linked ZTC layers. Non-recoverable devices, e.g.

Abstract: An electrostatic spray system including a spray device having an electrode for electrostatically charging coating particles emitted from the spray device toward an article to be coated, a high voltage electrostatic supply, and a high voltage insulated electrical cable interconnecting the electrostatic supply and the spray device electrode. The high voltage cable includes a fibrous resistive core, preferably fabricated from silicon carbide fibers, a fiber-restraining layer of insulative thread tightly wrapped spirally around the entirety of the core to prevent fiber ends from projecting outwardly from the core, an outer dielectric sheath, and an intermediate sheath sandwiched between the spirally wound inner fiber-restraining layer and the outer dielectric sheath and having a resistivity lying between that of the inner resistive fiber core and the outer dielectric sheath.

Abstract: A wall, floor or ceiling heater comprises a plurality of self regulating, preferably PTC conductive polymer, heater elements each of which is connected to two or more connection elements. The elements are held by a support. In a preferred embodiment the heater elements are positioned parallel to each other, and perpendicular to the connection elements. The support is preferably made from a rigid material which is hinged to allow the heater to be folded or rolled for easy transport.

Abstract: This invention concerns a heating pipe for panel heaters disclosed on walls, ceilings or floors to heat a room. The pipe is essentially constructed of a pipe itself, an electric heating wire running through it and aluminum granules stuffed between the two. Because of the simple structure, the production, the installment and the maintenance costs are cheap; as a matter of course, there is no additional need of a circulation pump for heating media and safety devices to watch the leak of heating media or the break of the pipe. Moreover, because spherical aluminum granules are closely packed, the heat conductivity is very good, which minimizes the heat loss and reduces the time to heat up a room. Also, the heat capacity is so small that frequency room temperature control by means of an automatic on-and-off mechanism has becomes possible.

Abstract: A planar heat generator comprises a heating element of metallic foil; a first pair of sheets made of a plastic material which are bonded to each other so that the heating element is interposed therebetween; a second pair of sheets made of a plastic material which are bonded to the outer surfaces of the first pair of sheets, respectively; and a pair of protective covers which are made of a plastic material having a melting point at least approximate to that of the material of the second pair of sheets. The protective covers are larger in area than the second pair of sheets and are bonded by fusion not only to the outer surfaces of the second pair of sheets, respectively, but also to each other at peripheral areas which extend beyond the peripheral margins of the second pair of sheets.

Abstract: The present invention relates to the technical field of fluid heater devices, and more particularly to an electric immersion heater for use in electro-plating, metal preparation, finishing applications in the electronics industry (e.g. preparation of printed circuits). The invention more specifically provides a new and improved electric immersion heater design that includes, in combination, a unique flexible cable structure enabling small diameter coils (made primarily from a fluoroplastic material) which, in turn, are mounted on a support frame structure. This provides an inexpensive heater assembly that has optimum heat transfer capability in liquid treating mediums.

Abstract: Automotive ignition wire with a high temperature rating, excellent electrical insulating properties, heat resistance, oil resistance and abrasion resistance is described. The wire utilizes a conductor made up of a glass fiber-cotton fiber braid on a graphite impregnated glass layer. Overcoating the conductor is an adhesion promoting polymer layer, an extruded thermosetting semiconducting polymer layer overcoated with a glass braid layer and a polymer jacket material. The polymer jacket material comprises a polymeric mixture of ethylene vinyl acetate and ethylene-propylene-diene monomer stabilized with a mixture of a phenolic antioxidant and a metal salt antioxidant.

Abstract: Automotive ignition wire with a high temperature rating, excellent electrical insulating properties, heat resistance, oil resistance and abrasion resistance is described. The wire utilizes a conductor made up of either a helically wound metal conductor on a radio frequency insulating polymer overcoated on a polymer adhesive layer on a glass fiber bundle; or a glass fiber-cotton fiber braid on a graphite impregnated glass layer. Overcoating either one of the conductors is a semiconducting polymer layer, an ethylene-propylene-diene monomer containing polymer layer optionally overcoated with a glass braid layer and a polymer jacket material. The polymer jacket material comprises a polymeric mixture of ethylene vinyl acetate and ethylene-propylene-diene monomer stabilized with a mixture of a phenolic antioxidant and a metal salt antioxidant.

Abstract: Automotive ignition wire with a high temperature rating, excellent electrical insulating properties, heat resistance, oil resistance and abrasion resistance is described. The wire utilizes a conductor made up of either a helically wound metal conductor on a radio frequency insulating polymer overcoated on a polymer adhesive layer on a glass fiber bundle; or a glass fiber-cotton fiber braid on a graphite impregnated glass layer. Overcoating either one of the conductors is a semiconducting polymer layer, and a polymer jacket material. The polymer jacket material comprises a polymeric mixture of ethylene vinyl acetate and ethylene-propylene-diene monomer stabilized with a mixture of a phenolic antioxidant and a metal salt antioxidant.

Abstract: A self-regulating heat producing strip is disposed along each wall of a room. The strip includes at least one pair of spaced apart electrical conductors extending longitudinally along the base of at least one wall and spaced therefrom. Self-limiting conductive material is in physical contact with and forms a heat generating zone between the conductors. An electrically insulated jacket longitudinally covers the conductors and the self-limiting conductive material. Connectors are provided for connecting the conductors to a power source to generate heat in the heat generating zone between the conductors.

Abstract: An ignition cable in which a thin tape or film of ethylene terephthalate is wrapped tightly around an inner layer of rubber insulation, coaxial with the core and inside the outer insulating jacket.

Abstract: A heating cable includes a pair of spaced apart electrical conductors extending the length of the cable. A matrix of filled polymeric material in physical contact with the conductors forms a heat generating web therebetween. The filled polymeric material has a volume resistivity selected to provide a predetermined heat output per unit length of cable. A plurality of macroscopic perforations are punched through the web between the two conductors so that the actual heat output per unit length of cable is a desired value less than the predetermined heat output per unit length. An electrically insulative jacket longitudinally covers the conductors and the web.

Abstract: An assembly comprising a flexible corrugated metal tube and an elongate resistive heating element that is within the tube and which can be connected to a power supply to provide an elongate electrical heater. The tube has a wall thickness less than 0.012 inch, a corrugation depth greater than 0.030 inches and a distance between corresponding points in adjacent corrugations from 0.02 inch to 0.75 inch. The corrugations extend around the entire periphery of the tube.

Abstract: An electrostatic spray system including a spray device having a coating-charging electrode, a source of high voltage electrostatic potential, and a resistive path for safely transmitting high voltage between the electrode and the electrostatic supply. The resistive high voltage transmission path is composed of plural parallel-connected continuous silicon carbide fibers.

Abstract: A heat tracing tape which can be cut to required lengths has a heating element comprising at least two lengths of woven or braided resistance wire each in the form of a flat strip. The strips are encased in extruded silicone rubber whereby they are spaced from one another. The strips are electrically connected at one end by a connector and the tape is provided with a power supply termination either at its other end, or at a T-branch connection, for connecting the tape to the power control system. The power control system is adjustable to set an estimated value of power required to maintain a predetermined process temperature. The system automatically adjusts the power supplied to the tape to the estimated value by means of a feedback control system. A process temperature sensor also regulates the power supplied to the tape in accordance with a sense temperature.

Abstract: Elongate electrical devices, comprising two conductors with electrical elements connected in parallel between them, have improved performance if the power supply is connected to one conductor at the near end and to the other conductor at the far end. Particularly useful devices are heaters, e.g. PTC conductive polymer heaters. The power supply is connected to the far end of the device through a connection means whose electrical properties can be correlated with those of the device in order to obtain a wide range of useful results. For example the connection means can have PTC, NTC or ZTC character and can be a simple conductor or another elongate device. The power supply can be DC or single-phase, two-phase or three-phase AC.

Abstract: An electric immersion heating apparatus for heating highly corrosive liquids includes a flexible cable-type immersion heater having a continuous coiled resistance heating element disposed in axially spaced pitches and being enclosed in a continuous tubular outer jacket formed of a flexible plastic material, such as polytetrafluoroethylene with a PFA side chain, resistant to chemical attach by highly corrosive liquids. The outer jacket is received over the coiled heating element in closely fitting relationship and has a wall thickness sufficiently thin to provide efficient heat transfer from the coiled element to the liquid being heated. Because of its thinness the outer tubular jacket is subject to permeation of damaging corrosive vapors through the jacket to the coiled heating element.