Multichannel tape for enclosing optical fibre - to be wound about telecommunication cable, to protect fibres during mfr. of armoured cable for underwater use

摘要

Optical fibres to be incorporated into a telecommunication cable having a strong steel core e.g. for underwater signal repeater cables, are preassembled into individual hollow channels on a flexible strip which can be wound helically about the core. The strip may be a laminate of a flat tape and a tape having longitudinal channels of e.g. triangular or trapezoidal section. The channels are filled with a polymerisable hydrophobic matl. such as polybutene. Enclosure protects the optical fibres during lay-up about the core and subsequent envelopment by insulating and/or armoured sheaths or covers. It is also simpler to assemble than designs where the cables are laid in open superficial channels along the coreor a coaxial sleeve. The multichannel tape is pref. secured by overwrapping with polyethylene terephthalate tape prior to envelopment by a sheath of high density polyethylene. The multichannel strip is opt. made by laminating flat and undulating strips of ductile Al sheet coated with polyethylene and welded together. Pref. the steel core cable is coated with a sheath of polyethylene and welded together. Pref. the steel core cable is coated with a sheath of polyurethane.