Fibre-optics cable basic element mfr. - to obtain welded metal sheath contg. over-long optical fibres

摘要

In the mfr of a basic element for a fibre-optics telecommunications cable comprising overlong optical fibres in a closed metallic sheath, in which the sheath is a longitudinally seam welded tube formed from metallic strip, the novelty is that (a) the metal strip is reversibly elongated (pref by heating) wrt the fibre length for a certain tube section, before or during forming of the strip to tube; and (b) the optical fibre is fed into the region of the elongated tube section of the tube being formed. Appts for carrying out the process includes a contact thermocouple comprising a pair of conventional thermocouple strips which slide on the formed tube.