Light conductor with optical fibres inside three consecutive layers - has its fibres loosely embedded in filling paste, then inside second polymer with higher thermal stability and outermost extruded sleeve

摘要

Light conductor has at least one optical fibre embedded in a filling and enclosed inside an outer sleeve. The optical fibre is in an inner layer of filling around which is at least one outer layer which has a higher thermal stability and/or higher viscosity than the inner filling layer. The complete construction pref. has the optical fibres (LW1-LWn) in their inner filling (IFS) inside the outer filling (AFS) and the final outermost sleeve (AH). The optical fibres themselves (LW1-LWn) are loose in the inner filling (IFS) and can move relative to each other; their number off from 1 - 20. They can be hollow type or in bundles. They (LW1-LWn) can be loosely twisted, in alternating directions if desired; they are all protectively coated with polymer. Their embedding filling (IFS) is relatively soft to allow their movement. The substance used for the filling is e.g. a paste and thisotropic resistant to oil and water. The outer filling (AFS) has a higher thermal stability to withstand the application of the outermost extruded sleeve (OE) while it (OE) is still hot. The outer layer (AH) is pref. e.g. polyether- sulphone or polybutylene terephthalate; if it is a two-ply type its inner layer is e.g. polyetherimide, polyethersulphone or polyphenylenesulphide and its outer layer is e.g. polybutylene terephthalate but pref. high density polyethylene. ADVANTAGE - The construction is reliably, cheaply and safely filled and ensures that the filling cannot escape. The inner filling can be selected to allow sufficient movement of the conductor(s).