US 6,185,351 B2 · All-dielectric, self-supporting, loose-tube cable with optical fiber ribbons

Abstract

An all-dielectric, self-supporting (ADSS), loose-tube fiber optic cable includes a plurality of buffer tubes respectively containing stacks of optical fiber ribbons. The buffer tubes are longitudinally stranded around a longitudinally extending central strength member to define a lay length. A longitudinally extending outer strength assembly extends around the plurality of buffer tubes, and a longitudinally extending sheath extends around the outer strength assembly. A first end of a section of the cable can be attached to a first pole extending upward from the ground and a second end of the section of the cable can be attached to a second pole extending upward from the ground so that the section is suspended between the poles and the section is tensioned due to the weight of the cable. The arrangement of the buffer encasements and the optical fiber ribbons is such that the optical fibers are strained by tensioning of the fiber optic cable that exceeds a predetermined value, and any attenuation of optical signals propagating through the optical fibers is negligible for optical fiber strain up to approximately 0.3 percent. For example, the arrangement of the buffer encasements is preferably characterized by a lay length of at least approximately 400 millimeters. A longitudinally extending inner sheath can extend around the plurality of buffer encasements so that the outer strength assembly is positioned between the inner sheath and the outer sheath.

Claims24

Dependent claims

An all-dielectric, self-supporting fiber optic cable that is adapted to be subjected to constant tensile loading during use, the fiber optic cable comprising:

a longitudinally extending central strength member;
a plurality of stacks of optical fiber ribbons, wherein each optical fiber ribbon comprises an array of optical fibers that are bound together as a unit;
a plurality of buffer encasements respectively containing the stacks of optical fiber ribbons, wherein each buffer encasement is longitudinally stranded around the central strength member to define a lay length of at least approximately 400 millimeters, and for each of the stacks of optical fiber ribbons and its respective buffer encasement the maximum diagonal cross-dimension of the stack of optical fiber ribbons divided by the interior diameter of the buffer encasement is not less than approximately 0.68;
a longitudinally extending outer strength assembly extending around the plurality of buffer encasements;
and
a longitudinally extending sheath extending around the outer strength assembly.

3 more elements

A method of deploying a fiber optic cable, comprising the steps of:

providing a fiber optic cable, the fiber optic cable comprising:
a longitudinally extending central strength member,
a plurality of stacks of optical fiber ribbons, wherein each optical fiber ribbon comprises an array of optical fibers that are bound together as a unit,
a plurality of buffer encasements respectively containing the stacks of optical fiber ribbons, wherein each buffer encasement is longitudinally stranded around the central strength member,
a longitudinally extending outer strength assembly extending around the plurality of buffer encasements, and
a longitudinally extending sheath extending around the outer strength assembly;
and
suspending a section of the fiber optic cable between suspending members so that the fiber optic cable is constantly subjected to tensile loading due at least to the weight of the cable, the suspending step comprising the steps of attaching a first end of the section of the fiber optic cable to a first suspending member and attaching a second end of the section of the fiber optic cable to a second suspending member.

5 more elements

Dependencies are inferred from the claim text.

All-dielectric, self-supporting, loose-tube cable with optical fiber ribbons

Life of this patent

All-dielectric, self-supporting, loose-tube cable with optical fiber ribbons

Life of this patent

Abstract

Claims24