Optical fiber communications cable
First Claim
1. A communications transmission cable comprising(a) a core member having a longitudinal axis and comprising at least one optical fiber and first means surrounding the fiber;
- (b) a first jacket having a longitudinal axis and an inner and an outer surface and comprising a polymeric material, the first jacket enclosing the core member and being substantially coaxial with the core member; and
(c) three groups of non-metallic strength members, disposed between the inner and the outer first jacket surfaces in a generally longitudinal direction, each group of strength members comprising one or more strength members and having a longitudinal axis, the longitudinal axis of each group of strength members being a distance R from the first jacket longitudinal axis and being spaced substantially 120°
from the longitudinal axis of each of the remaining two groups, with R>
1.155(r+rs), each strength member comprising a plurality of filaments that are gathered together, and each strength member being coupled to the first jacket.
4 Assignments
0 Petitions
Accused Products
Abstract
An optical fiber cable includes a first jacket, typically comprising a polyvinyl chloride material, a core member comprising at least one, typically ≦10, optical fiber(s), and a core wrap loosely surrounding the optical fiber(s). The optical fiber(s) typically is (are) slightly overstuffed. The cable further comprises three non-metallic strength members (or groups of strength members) completely embedded in the first jacket and coupled thereto. In cables containing three strength members, the coupling is typically characterized by a pull-out strength of at least 25, preferably more than 40, lbs/in of strength member. Each strength member comprises a multiplicity of impregnated filaments, preferably borosilicate glass filaments impregnated with a urethane. The preferred cable typically has a circularly symmetric cross section, with the three strength members, each of radius rs, disposed longitudinally, their axes a distance R from the axis of the first jacket, with R>1.155(r+rs) where r is the inner radius of the first jacket. In one embodiment of the invention, the voids between the optical fiber(s) and the core wrap is filled with a filling compound, e.g., a fire retardant grease composition. In another embodiment, the cable further comprises a metal member, e.g., a steel tape, that contactingly surrounds the first jacket, and a plastic, e.g., polyvinyl chloride, outer jacket that contactingly surrounds the metal member. The cable can advantageously be used in the local distribution network, including in external plant applications such as distribution or buried service cable, and indoor applications such as riser or plenum cable.
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Citations
17 Claims
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1. A communications transmission cable comprising
(a) a core member having a longitudinal axis and comprising at least one optical fiber and first means surrounding the fiber; -
(b) a first jacket having a longitudinal axis and an inner and an outer surface and comprising a polymeric material, the first jacket enclosing the core member and being substantially coaxial with the core member; and (c) three groups of non-metallic strength members, disposed between the inner and the outer first jacket surfaces in a generally longitudinal direction, each group of strength members comprising one or more strength members and having a longitudinal axis, the longitudinal axis of each group of strength members being a distance R from the first jacket longitudinal axis and being spaced substantially 120°
from the longitudinal axis of each of the remaining two groups, with R>
1.155(r+rs), each strength member comprising a plurality of filaments that are gathered together, and each strength member being coupled to the first jacket. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A communications transmission cable comprising
(a) a core member having a longitudinal axis and comprising at least one optical fiber and a core wrap surrounding the at least one optical fiber, the core wrap comprising a woven, polymer-coated fiberglass tape that is longitudinally wrapped over the optical fiber, leaving voids between the core wrap and the optical fiber; -
(b) a first jacket having a longitudinal axis and an inner and an outer surface and comprising polyvinyl chloride, the first jacket being substantially coaxial with the core member and contactingly surrounding the core member, the first jacket having substantially circular cross section, with distance r from the first jacket longitudinal axis to the first jacket inner surface; and (c) three non-metallic strength members, each strength member having an axis and a radius rs, the strength members disposed between the inner and outer first jacket surfaces in generally longitudinal direction, the strength member axes being a distance R from the first jacket axis, where R>
1.155(r+rs), the strength member axes located 120°
apart, each strength member comprising a plurality of filaments that are impregnated with a coupling-promoting material and that are gathered together, each strength member being coupled to the first jacket, the coupling characterized by a pull-out strength of at least 40 lbs/in of strength member. - View Dependent Claims (16, 17)
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Specification