Abstract: An optical cable has a core (1) which comprises at least one optical conductor (7) stranded around a central member (6). The core (1) with the optical conductors (7) is enclosed by a reinforcing layer (2) comprising strength members (11). These strength members (11) are profiled bodies with flat cross section wherein the side faces (12, 13) of adjacent members (11) are in contact with each other and support each other. The strength members (11) form around the core (1) a closed jacket stable against changes of diameter. The optical conductors (7) are stranded around the central member (6) so that after each turn the direction of stranding changes, i.e. one turn to the right, the next to the left, then again to the right, etc. Thereby a wave-like stranding of the optical conductors (7) is formed.
Abstract: Modern synthetic fibers, e.g. made of aromatic polyamides of high tensile strength have not achieved their potential for use as heavy-duty cables because of their smooth surface which gives rise to considerable difficulties in the transfer of high tensile forces, since they slip out of the clamping sleeves, and other force-transfer means based upon static friction, before reaching their ultimate tensile strength. This problem was solved in the invention by applying to the force-transmitting region thereof an impregnating material which breaks down into powder in the area to which the stress is applied, when the compressive or flexural stress exceeds the ultimate stress limit of the impregnating material. Particularly suitable for this purpose are natural resins, more particularly colophonium.
Abstract: In known overhead telephone cables comprising two individual encased and stranded conductors, each consisting of a plurality of copper wires for the transmission of signals, and steel wires for load bearing purposes, the problem of relatively high susceptibility to corrosion at leakage points in the casing due to water penetration is solved by replacing the steel wires with bundles of stretch-resistant synthetic fibres, e.g. aromatic polyamide fibres, and the tendency of spirally wound synthetic fibres, or bundles of fibres, to shift towards the center of the conductor when the cable is under tension, and thus allow the cable to elongate is prevented by arranging the copper wires and bundles of fibres so that they position themselves mutually. The coherency of the bundles of fibres required for this purpose may be obtained, for example, by stranding or twisting the fibres in the bundle or impregnating the bundle with a resin, preferably colophony.
Abstract: The tendency of modern high strength synthetic fibres, e.g., made of aromatic polyamides, when utilized for tension load-carrying purposes in association with an overhead cable arranged parallel thereto within a common protective covering to slip under load out of the clamping members connected thereto before the load reaches its ultimate tensile strength is overcome by impregnating a bundle of such fibres with an impregnating material capable of breaking down into particles when subjected to sufficient compressive stress which is broken down into such particles by the application of the clamping member, the resultant particles exerting within the clamped region a wedging action between the individual fibres and at the exterior of the bundle as a whole upon the application of the tension load to the bundle. Particularly suitable impregnating materials are natural resins, especially colophonium.
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.