Bell Telephone Laboratories

American Telephone & Telegraph Co., At&t Bell Laboratories

At&t Technologies, Inc.

George Harry Webster

Manuel R Santana

Michael D Kinard

Wendell G Nutt

Andrew J Panuska

Mickey R Reynolds

An optical fiber cable (20) includes a core (21) comprising at least one optical fiber (24) which is enclosed in a tubular member (34) and which includes a sheath system (40). The sheath system includes two strength members 42--42 which extend linearly longitudinally along the cable parallel to a longitudinal axis (29) of the cable. The strength members are enclosed in a plastic jacket (46). The strength members have predetermined relative tensile and compressive stiffnesses. The stiffnesses are such that the strength members are capable of withstanding expected compressive as well as tensile loading and are coupled sufficiently to the jacket to provide a composite arrangement which is effective to inhibit contraction and which controls the position of the neutral axis during bending while providing suitable flexibility. The strength members in a preferred embodiment are made of a metallic material such as steel and have tensile and compressive stiffness which are substantially equal to cause the plane of bending to extend through the strength members. In other embodiments, the core is filled with a waterblocking material, the tubular member is enclosed by a water absorbent tape and/or a metallic shield and metallic conductors may extend colinearly with the strength members.

Optical fiber cable

A multipair telephone cable especially designed to carry interoffice traffic consists of copper conductors insulated with expanded plastic with or without a solid plastic skin. The copper gauge size, insulation expansion factor and dielectric diameter are uniquely designed to consume a minimum of cable cross-section area while permitting use of the cable to provide voice frequency circuits in a manner comparable to normal; 24-gauge cable as well as to provide carrier frequency circuits operating in the range of from about 100 kHz to 8.0 MHz comparably to normal 22-gauge cable. The cable includes pairs twisted according to a constant twist frequency spacing concept.

Transmission path between nearby telephone central offices

Growing community of inventors

Dunwoody, GA, United States of America

George Harry Webster