| 摘要 |
<p>PURPOSE:To make it possible to insert a glass fiber line into a single core electric cable, undersea water supply pipe, etc., by making at least one of steel wires of steel armor a hollow steel wire of a specified cross sectional area ratio or greater and inserting the glass fiber into the hollow wire. CONSTITUTION:At least one steel wire 24A of a plurality of steel wires 24, while being of the same material with that of other steel wires 24B, is of a hollow cross section having a cross sectional area of 80% or more, into which a glass fiber core wire 26 is inserted. With the cross sectional area of the steel wire 24A being 80% or more of that of the steel wire 24B, lowering in the moment of inertia of its cross section is kept 5% or less. As a result, the steel wire 24A has almost the same mechanical strength with the wire 24B to prevent the core wire 26 from being damaged with external forces.</p> |
