VERFAHREN UND VORRICHTUNG ZUR HERSTELLUNG VON DEFINIERTEN LICHTWELLENLEITERLAENGEN IN LICHTLEITADERN.

摘要

The sheath is extruded at an adjustable draw-off velocity and loosely contains at least one optical fibre. This fibre is brought into predetermined one-sided contact with the inner sheath wall by passing the cable around at least one deflecting roller (UR3) after the extruder. Subsequent cooling then produces a predetermined shrinkage of the sheath. To obtain the required relative length variation between cable sheath and optical fibre(s), the effective dia. (D) of the roller is varied. The cable passes over at least 180 deg. pref., more than 270 deg. of the roller. This control (STE) is pref. in response to a first sensor (VM1) measuring the fibre draw-off speed and a second sensor (VM2) measuring the cable speed and possibly a sensor (DM) measuring the cable dia.