| 摘要 |
The invention concerns a secondary casing construction for optical cables. The secondary casing construction comprises a secondary casing tube 1 within which lie optical fibres 3 in fibre channels 2.1 - 2.5, whereby the tube encloses the fibres with room to spare to allow for axial movement between the fibres and the tube. One problem with the present design of secondary casings is that, in this connection, it is not possible to achieve a reliable, simple method of producing the cable and, at the same time, ensure a construction which would provide plenty of room for the optical fibres to move within the tube without risk of compression, or of failing to reach their minimum bend radii. This problem has, in the secondary casing construction according to the invention, been solved such that at least one of the fibre channels 2.1 - 2.5 passing through the tube 1 twists forwards spiral fashion in the tube's longitudinal direction, and at any given tube cross section will lie assymetrically in relation to the tube's central axis A. <IMAGE>
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