Bicc Public Limited Company

Bicc Plc

Harvey, Peter

Peter Harvey

Andrew Robert Fry

Eric W Crew

Paul Radage

A helically grooved flexible optical cable core comprising a plurality of helically laid flexible bodies 1 of sector-shaped cross-section is manufactured by drawing a multiplicity of flexible non-metallic reinforcing elements 2 under tension through electrically insulating plastics material 3 in a semi-liquid state; causing the plastics encapsulated reinforcing elements to pass through an elongate die 23 having an outlet orifice 25 of sector-shape, which die, between its ends, is of such a shape that reinforcing elements adjacent the arcuate surface 4 of the body are travelling at a greater linear speed than reinforcing elements remote therefrom, and which has a blade 26 protruding inwardly of the die and forming in the arcuate surface of the body a longitudinally extending groove 5; causing the body as it emerges from the die to follow a helical path with its grooved arcuate surface outermost and so cooling the helically advancing body that the plastics material sets; partially filling the groove in the arcuate surface with a grease and continuously feeding an optical fibre into the grease in the groove; laying up the helically advancing body with a plurality of helically advancing bodies of similar cross-section and construction to form a flexible core of circular cross-section which is rotating about its longitudinal axis; and taking up the rotating core in such a way that any residual torsion in the core arising from said rotation is removed.

Manufacture of a flexible core for an optical cable

An optical cable, especially suitable for use as an aerial cable, comprises a circumferentially rigid flexible tube which is of composite form and comprises a plurality of elongate flexible bodies helically laid up together, each of which bodies is of a cross-section approximating to a sector of an annulus and comprises extruded electrically insulating plastics material and a mulitiplicity of longitudinally stressed elongate flexible non-metallic reinforcing elements encapsulated in said plastics material, e.g. polypropylene or nylon, the multiplicity of non-metallic reinforcing elements being substantially evenly distributed throughout the cross-sectional area of the body. An outer protective non-metallic sheath surrounds the tube and at least one flexible optical guide, e.g. a separate optical fibre, optical bundle or optical fibre ribbon structure, is housed in the bore of and is movable relative to the tube.

Aerial optical cable and its method of manufacture

A simple and inexpensive dead end fitting for securing an overhead conductor loosely housing an optical guide to a tower comprises a sleeve of malleable metal or metal alloy, open at each of its ends, for compression jointing to the conductor; a steel termination in screw threaded engagement with the sleeve and having a clevis for securing the fitting to a tower; and a lug welded to the sleeve for effecting electrical connection to a jumper cable. The lug engages in a notch in the adjacent end of the termination to lock positively the screw threaded engagement between the sleeve and termination.

Dead end fitting for use in overhead electric and optical transmission

In an inexpensive and simple method of effecting a joint between two overhead electric conductors incorporating optical fibres or between an overhead electric conductor incorporating an optical fibre and an optical cable extending to a sub-station or other location, at least a part of each or the overhead conductor is introduced into a metal sleeve extending from a wall of a metal housing and the sleeve is compression jointed to the conductor to effect a mechanical and electrical joint between the conductor and the housing. The part of the conductor protruding into the housing is cut back and a joint is effected between the optical fibres of the two overhead conductors or between the optical fibres of the overhead conductor and the optical cable that has been introduced into the housing. The housing is sealed to render it fluid tight and is preferably filled with petroleum jelly. An elongate metal shroud may be assembled around the metal housing and be so shaped as to provide aerodynamic and corona protection.

Overhead electric and optical transmission systems

An electric cable support system is provided having means for supporting electric cables and an elongate metal duct housing said support means and divided transversely into separately formed parts that are detachably secured together, the internal surface of at least a part of the length of the elongate duct is lined with a continuous wall of thermal insulating material and/or absorbing material comprising a closed envelope, or at least two closed envelopes arranged adjacent one another, containing non-flammable evaporative cooling fluid. Preferably, the or each envelope is made of a flexible material which will melt at a temperature at or near the boiling point of the cooling fluid. In the event of an external fire, when the temperature of the duct wall is sufficient to melt the flexible material of an envelope, the cooling fluid will start to evaporate and cool the duct interior.

Growing community of inventors

London, United Kingdom

Peter Harvey