초록 ▼

An optical fibre transmission line is installed by first installing a conduit having one or more bores and subsequently inserting flexible, lightweight optical fibre members containing the optical fibres into the bores. The optical fibre members are propelled by employing the fluid drag of air, or a

An optical fibre transmission line is installed by first installing a conduit having one or more bores and subsequently inserting flexible, lightweight optical fibre members containing the optical fibres into the bores. The optical fibre members are propelled by employing the fluid drag of air, or another suitable gas, passed at high velocity through the bores.

대표청구항 ▼

A method of advancing a lightweight and flexible optical fibre member along a previously installed tubular pathway in situ, said tubular pathway extending between two points, said method comprising: (a) inserting the free end of a lightweight and flexible optical fibre member into the previously ins

A method of advancing a lightweight and flexible optical fibre member along a previously installed tubular pathway in situ, said tubular pathway extending between two points, said method comprising: (a) inserting the free end of a lightweight and flexible optical fibre member into the previously installed pathway by applying to said fibre member a force in the direction of insertion; (b) inserting a gaseous medium into the pathway with a flow velocity much higher than the desired rate of advance of said fibre member through said pathway; and (c) propelling the free end and following portions of a fibre member along the pathway continuance of said insertion force in cooperation with fluid drag of said gaseous medium passed throughout the length of the pathway in the desired direction of advance such that the pulling force on the optical fibre is distributed throughout the length of said fibre then present in the pathway enabling the fibre member and its advancing free end to be advanced past bends which may be present in the pathway without an unacceptable pulling force being concentrated on any portion of the fibre, said gaseous medium having substantially higher velocity than said fibre member throughout the length of the pathway. Apparatus for installing a lightweight flexible optical fibre member into and along a length of previously installed tubular pathway between first and second ends of the pathway, said apparatus comprising: first means for flowing a gaseous medium within said pathway toward said second end at a flow velocity substantially higher than the desired fibre member advancement rate; second means for inserting and advancing a free end of said fibre member into said flowing gaseous medium by applying to said fibre member an insertion force directed towards said second end; and said first and second means cooperating to propel said fibre member through said tubular pathway by producing viscous drag forces distributed along the advancing length of the fibre member then disposed within the pathway while the fibre member advances at a velocity substantially less than the gaseous flow velocity until said free end of the fibre member reaches said second end of the pathway.