| 摘要 |
A composite overhead electric and optical conductor comprises a circumferentially rigid central metal. e.g. aluminium or metal alloy tube 2 having tightly disposed in its bore throughout its length a flexible optical guide 1 and, surrounding the tube 2, at least one layer 3 of helically wound electrically conductive metal or metal alloy e.g. steel wires 4. The flexible optical guide 1 comprises a central, preferably non-metallic, tensile resistant strength members, a layer 6 of optical fibres 7 wound helically around the central member 5 and, surrounding the layer of optical fibres, an overall plastics sheath 8 of e.g. cross-linked polyethylene. The interstices between the optical fibres 7, between the fibres and the member 5 and between the fibres and the sheath 8 are filled with a cured resin e.g. photo-cured acrylic resin 9 so that the optical fibres are wholly encapsulated therein. The interstices between the optical fibres may be filled with a water-impermeable medium or accommodate water-swellable elements. The optical fibres may be colour coded. <IMAGE> |
