Abstract: A cable (20) specially suited for use in building plenums because of its low flame spread and smoke evolution includes a multiconductor core (22) which is enclosed in a sheath comprising an inorganic, cellular core wrap (31), a corrugated metallic barrier (40) and dual layers (51) and (52) of a polyimide tape which are wrapped helically about the barrier in a manner that avoids a compression of the core wrap. The sheath is effective to resist heat transfer inwardly toward the core by conduction while the metallic barrier reflects radiant heat. Advantageously, the sheath containerizes the core without unduly compressing it and thereby allows the intumescence of conductor insulation during a fire to form char which is effective to suppress the evolution of smoke and the propagation of flame.

Abstract: A method of reconstituting an external conductor of a coaxial cable which stands up well to bending and has good electromagnetic propagation. Solid non-perforated or woven strips are wound in a helix along the whole length of the part which is to be repaired and the ends of the intact external conductor and said strips are glued on these ends with an electrically conductive glue. Application to coaxial telephone cables.

Abstract: An anti-holiday cable armor for submersible electrical cables comprising two generally helically wrapped, overlapping metal straps, the second metal strap being wrapped longitudinally in a direction opposite to the direction of wrap on the first metal strap, for providing anti-holiday protection when the cable is pulled in either direction is disclosed.

Abstract: A repair coupling for flexible electrical conduit comprised of helically wrapped loosely interlocked metallic strip, said coupling being characterized by its initially enlarged arcuate cross section adapted to be constricted into tube form, the interrupted perimeter of the initial cross section providing an opening longitudinally coextensive with the coupling body for the lateral reception of wires, the body being reformed to have a continuous circumference of predetermined diameter for threaded engagement into the conduit sections joined thereby.

Abstract: A shielded wire having a central core and an insulation layer coated thereover. A shield layer separates the insulation layer from a ground wire and is formed by a composite tape having a metal surface and an adhesive surface. The metal surface is longitudinally folded to cover a portion of the adhesive surface and the tape is helically wound with the folded surface on the outside to form alternate helical patterns of the metal and adhesion layers. A sheath covers the shield layer and the ground wire and is bonded to the adhesive layer while the ground wire is in contact with the outside metal layer. The inside metal surface forms the shield.

Abstract: A thin-walled annular shell of high rigidity relative to its unit weight is provided. The wall of the shell is a composite material built up layerwise of glassy alloy strips of high transverse aspect ratio such that each layer is a strip wrapped at a substantially 45.degree. helix with respect to the elongate axis of the shell and with adjacent layers having alternating directions of wrap. Bonding between adjacent layers and between strips within each layer is accomplished in a selected manner such that the composite wall is structurally monolithic for thin-walled applications thereby taking substantially full advantage of the extraordinary strength properties of glassy alloy strip.

Abstract: A rigid plastic composite tube includes a first sleeve of helically braided metallic ribbons, a second sleeve engaged with the first sleeve either on the inside or outside thereof, the second sleeve being of helically braided fibrous strands, said sleeves being embedded in solid plastic material to form a unitary composite tubular structure.The method of this invention for fabricating such plastic composite tubes comprises the steps of braiding metallic ribbons and fibrous strands about an elongated form, conforming the ribbons to the shape of said form by tensioning the strands during the braiding thereof, impregnating the composite sleeve with liquid hardenable plastic, and then hardening the plastic thereby providing a solidified plastic composite sleeve.

Abstract: An apparatus for heating railroad rails such as those forming a railroad switch to prevent obstruction of the switch by ice and snow includes an elongate, bendable, high temperature heating cable disposed lengthwise against and along a side of the rail web. The cable comprises an electrical resistance heating wire encased in a high temperature resistant electrically insulating material confined inside a thermally conductive deformable metal sheath. An elongate, pliable heat insulating mat is disposed lengthwise against and along a length of the cable and portions of the rail web laterally adjacent thereto to prevent heat losses by convection or radiation from the cable length. An elongate substantially rigid casing member is fitted lengthwise over the mat and bears against the web side to confine the mat in place, and is held tightly in place against the rail web.

Abstract: A high frequency coaxial cable suitable for aerial and ultra-high-frequency lines of the type having a metal internal conductor, a plastic dielectric concentrically surrounding the internal conductor, an external conductor surrounding the dielectric and comprising a metal wire mesh and a plastic foil strip metallized on at least one side, and a plastic sheath enveloping the external conductor as an external protective cover, wherein the wires of the wire mesh are arranged in net-like configuration to define an open wire mesh enclosing the dielectric and the plastic foil strip is applied on the wire mesh in helical edgewise overlapping windings with its metallized side facing the wire mesh and is pressed into each single mesh opening of the wire mesh in form of a generally trough-like dent or dimple thereby short-circuiting each single mesh opening of the wire mesh.

Abstract: An electrical cable of the self-floating type for use in marine environments is provided with elements for taking up mechanical tractive forces. The electrical conductors of the cable are surrounded by an inner friction layer with a low friction coefficient. Around this layer a force equalizing layer of metallic material is provided and this layer is surrounded by hollow strands of soft plastic material. An outer friction layer of the same material as the inner friction layer surrounds the hollow strands and the whole system together with the elements for taking up the tractive forces is embedded in a cable mantle of rubber-like plastic material.

Abstract: A heat treating appliance coilable about steel piping for heating it before or relieving stresses in it after welding comprises an elongate reticulate sleeve of interlaced heat and oxidation wire having lengths of electrical heating cable each doubled back along itself and fixed inside and along the sleeve so as to form cable legs spaced apart in the sleeve and having terminal portions extending outside it, from respective openings near one end thereof, for connection with a current source. The sleeve has end portions extending beyond the cables therein, and each bent back upon itself into a loop, for securing the appliance in place on the structure to be heat treated.

Abstract: A high frequency coaxial cable exhibiting a low insertion loss and a low reflection coefficient, and incorporating an improved construction providing for convenient adjustment of impedance.