232results about "Cable insulation construction" patented technology

A transmission line for downhole tools that make up all or part of a tool string for drilling and production of oil, gas, and geothermal wells that can withstand the dynamic gravitational forces and other accelerations associated with downhole excavations. The transmission line comprises a metal tube, or outer conductor, that houses a coaxial wire inner conductor. A non-metallic dielectric material is interposed between the inner and outer conductors. The outer and inner conductors and the dielectric are sufficiently compressed together so that independent motion between them is abated. Compression of the components of the transmission line may be achieved by drawing the transmission through one or more dies in order to draw down the outer conductor onto the dielectric, or by expanding the inner conductor against the dielectric using a mandrel or hydraulic pressure. Non-metallic bead segments may be used in aid of the compression necessary to resist the dynamic forces and accelerations of drilling.

An axially arranged cable, such as a coaxial, triaxial, twinaxial, or armored cable which includes at least one serration on an insulative or conductive layer internal thereto and methods of manufacturing the same. These serrations may appear on insulators or inner jackets and are in physical contact with conductive layers such as shields which axially surround the insulative layers. The serrations generally increase the contact force between the insulative layers and the conductiver layers to help prevent separation of the cable core during stripping of the axial cable.

A small-diameter coaxial cable comprises a central conductor, an insulated covering layer arranged on the outer periphery of the central conductor and having air gaps continuous along the longitudinal direction and an outer conductor layer arranged on the outer periphery of the insulated covering layer. The insulated covering layer includes an inner annular portion covering the outer periphery of the central conductor, a plurality of coupling portions extending outward from the inner annular portion and an outer annular portion connecting the outer peripheral edges of the coupling portions to each other. Air gaps defined along the peripheral direction by the coupling portions are formed on the inner side of the insulated covering layer.

A communications cable is provided that reduces the additive distortion of intended information encoded as electromagnetic energy that propagates longitudinally along the cable by varying the propagation velocity along its length. The additive distortion is reduced by varying the propagation periodically at a frequency that is lower than the highest frequency at which said electromagnetic energy propagates along said cable.

A method of making a coaxial cable includes forming a conductive tube and setting a settable material therein to define an inner conductor. Forming may include advancing a conductive strip and bending it into a tube having a longitudinal seam. The settable material may be dispensed onto the conductive strip continuously with the forming. Alternately, the settable material may be dispensed onto the conductive strip prior to advancing. The dispensing may use a puller cord as the settable material or carrying some or all of the settable material. The method may further include forming a dielectric layer surrounding the inner conductor, and forming an outer conductor surrounding the dielectric layer.

A differential signal transmission cable has a pair of conductors arranged to be distant from each other and parallel to each other, an insulator covering the pair of conductors, and a shield conductor wound around the insulator. The insulator has an outer periphery shape of a transversal cross section in that a plurality of curved lines with different curvature radiuses are combined. The shield conductor has an inner periphery shape of a transversal cross section in that the plurality of curved lines are combined in accordance with the outer periphery shape of the insulator.

A multi-axial electrically conductive cable having a multi-layered core. The multi-layered core comprises one layer of insulating dielectric material and at least one additional layer of insulating dielectric material. The multiple layers of the core are separable and allow the multi-axial electrically conductive cable to be utilized in several electrical connections of varying impedances and different sized connections.

The amount of air dielectric in air core coaxial and twinaxial cables is increased by spacer structures installed between the center conductor and the outer shield which have provision for air voids or pockets running lengthwise. The extra air space provides lower effective dielectric constant for the cable. In one embodiment, a single-element extruded spacer is formed with air cavities or voids that run continuously throughout the length of the spacer. Several spacer "profiles" or cross-sections are disclosed that place less solid dielectric mass in proximity to the center conductor. The result is a greater volume of air dielectric, and hence a lowered cable dielectric constant. In a further embodiment the spacer is a circular cross-sectioned element consisting of a central dielectric strength member surrounded with foamed material. Strength strands such as Kevlar(R) may be added to the spacer.

A differential signal transmission cable includes a pair of differential signal lines arranged in parallel to each other, an insulation for bundle-covering the pair of differential signal lines, and a shield conductor wound around an outer periphery of the insulation The insulation is configured such that an outer circumference thereof in a cross section perpendicular to a longitudinal direction thereof has an oval shape formed with a continuous convex arc-curve The oval shape has a width in a first direction along the arrangement direction of the pair of differential signal lines being larger than a width in a second direction orthogonal to the first direction

The invention provides an insulated wire having a conductor and an insulator of paste extruded PTFE fine powder around the conductor. The paste extruded insulator has at least one closed continuous longitudinal air channel spaced apart from the conductor. The invention further provides a process for forming an insulator around a conductor by paste extruding lubricated PTFE fine powder in an extrusion device comprising a die, mandrel, and at least one channel-forming member. The die and mandrel form a converging chamber leading to an extrusion orifice and the channel-forming member is positioned in the orifice. The mandrel has a central bore for supplying the conductor. Lubricated PTFE fine powder is forced through the chamber and out of the exit of the orifice as a lubricated green extrudate around the conductor forming an insulator with at least one closed longitudinal air channel spaced apart from the conductor.

A thin coaxial cable is provided comprising an inner conductor; an outer conductor being an electroplated conductive metal layer; a thin electrically insulating layer made of a polymeric enamel resin or of glass of at most approximately 15 μm thickness separating said inner and said outer conductor; said insulating glass or polymeric enamel resin layer is coated with a layer of an adhesion promoting primer material or said insulating polymeric enamel resin layer is coated with a layer of ABS resin, and an electroless plated metal layer is deposited between said primer or ABS resin layer and said electroplated conductive metal layer.

A micro coaxial cable includes an inner conductor; an insulation layer having foaming cells and formed to surround the inner conductor; an over-foaming preventing layer formed to surround the insulation layer for the purpose of uniform forming of the foaming cells; a metal shield layer formed to surround the over-foaming preventing layer; and a protective coating layer formed to surround the metal shield layer. The over-foaming preventing layer restrains abnormal growth of foaming cells formed in the insulation layer such that the foaming cells are successively adjacently formed with uniform size. Due to the uniformity of foaming, the dielectric constant of the insulation layer is not locally different but uniform as a whole, thereby capable of improving transmission characteristics. In addition, the micro coaxial cable enables to transmit signals even at a high frequency transmission of GHz range, which was impossible in the prior art.

An electrical communications element having a foamed plastic insultation extruded about a conductor with said insulation including at least one component with more than 20% by weight of an ultra-high die swell ratio polymer (UHDSRP), preferably around 15% by weight. The UHDSRP is defined as greater than 55% die swell ratio and more preferably greater than 65% die swell ratio. The insulation also preferably includes at least a second component with a high degree of stress crack resistance, such that the combination of (minimally) these polymers will yield an insulation layer that has a unique combination of physical propeties yielding a high degree of foaming, small uniform cell structure, characteristically lower attenuation, and stress crack resistance capable of withstanding greater than 100 hours at 100° C. while coiled at a stress level of 1 times the insulation outside diameter without failure (cracking).

Fire-resistant coaxial cables are described as well as methods to manufacture them. The dielectric between the coax cable's central conductor and outer coaxial conductor ceramify under high heat, such as those specified by common fire test standards (e.g., 1850° F./1010° C. for two hours). The dielectric can be composed of ceramifiable silicone rubber, such as that having a polysiloxane matrix with inorganic flux and refractory particles. Because thick layers of uncured ceramifiable silicone rubber deform under their own weight when curing, multiple thinner layers are coated and serially cured in order to build up the required thickness. A sacrificial sheath mold is used to hold each layer of uncured ceramifiable silicone rubber in place around the central conductor while curing. The outer conductor can be a metal foil, metal braid, and/or corrugated metal. Another layer of extruded ceramifiable silicone dielectric or an outer wrap of ceramic fiber yarn surrounds the outer conductor and continues to insulate it from the outside if a low smoke zero halogen jacket burns away. Methods of testing and installation are described.

In a high-frequency coaxial cable (1), an internal solid layer (3), an insulation layer (4) made of a foam resin, an external solid layer (5), and an external conductor (6) are provided on the periphery of an internal conductor (2) in this order. The external solid layer (5) has a dielectric dissipation factor of 1.0×10⁻⁴ or less at 2 GHz. Thereby, the voltage standing-wave ratio and the attenuation of the high-frequency coaxial cable (1) are reduced.

A separator for a communication cable includes a plurality of barriers formed in a radial direction so that at least two pair units, in each of which at least two insulation-coated wires are spirally twisted, are received in spaces formed by the barriers one by one so as to separate the pair units from each other. At least one of the barriers has a relatively greater thickness than the other barriers. Thus, a communication cable having the separator may prevent PSNEXT (Power Sum Near and Crosstalk) caused by interference between adjacent wires when a high frequency signal is transmitted through the wires.