| 摘要 |
A fire-proof optical fibre cable comprises a signal carrying, optical fibre (2a-2d), which is embraced by a protecting jacket (4), preferably of organic material. The jacket (4) may be filled with silicone grease. The protecting jacket (4) is surrounded by in inorganic fire retardant material (5) which during a fire provides a pipe substituting the protecting jacket (4). Preferably the protecting jacket (4) is covered by mica tape, possibly an inorganic mass or another material which during fire is subjected to a sintering process and forms a fire protecting pipe. Preferably the protecting jacket (4) and its surrounding mica tape (5), or a group of such assemblies, is surrounded by a layer of glass tape (6), as well as a filler jacket (7), and another glass tape (8), possibly reinforced with steel therearound. Further, the cable may be equipped with an outer jacket (9) of a material which yields a protective ash during fire. <IMAGE> |
