Lucent Technologies Inc.

At&t Bell Laboratories

Western Electric Company, Inc.

At+t Corp.

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

At&t Technologies, Inc.

James Robert Holman

Terry D Mathis

Montri Viriyayuthakorn

Parry A Moss

Lionell Graham

Candido J Arroyo

John T Chapin

Michael D Kinard

Carla Green Wilson

Alfred S Hamilton

David S Hancock

Palmer D Thomas

Robert N McIntyre

Loinell Graham

Jay T Loadholt, Iii

Emanuele Scalco

A simplex optical fiber cable includes an optical fiber, a buffer surrounding and in contact with the optical fiber, a layer of strength fibers disposed about the buffer, and a sheath member surrounding and in contact with the yarn layer. In cross section the cable has a diameter of less than 2.0 millimeters (mm) and thus is much smaller in diameter than optical fiber cables presently available. Preferably, if the buffer is relatively thin a slick substance is applied to the outer surface of the buffer to allow the buffer and the strength fiber layer to slide relation to each other. If the buffer is relatively thick, a friction-reducing substance can be applied to the optical fiber to facilitate stripping of the buffer from the fiber a duplex optical fiber cable includes two simplex optical fiber cables having their respective sheaths joined to produce a figure-eight configuration. A second duplex optical fiber cable includes two simplex optical fiber cables arranged side-by-side and an oversheath surrounds both cables.

Sub-miniature optical fiber cables, and apparatuses and methods for making the sub-miniature optical fiber cables

A simplex optical fiber cable of this invention includes an optical fiber, a buffer preferably of nylon, surrounding and in contact with the optical fiber, a yarn layer with strength fibers, preferably aramid fibers, disposed about the buffer and a sheath preferably formed of polyvinyl chloride (PVC) surrounding and in contact with the yarn layer. In cross-section, the simplex optical fiber cable has a diameter less than 2.0 millimeters (mm), and thus is much smaller in diameter than optical fiber cables presently available. Preferably, if the buffer is relatively tin providing limited protection to the optical fiber, a slick substance such as talc is applied to an outer surface of the buffer before the yam layer is disposed thereon. The slick substance allows the buffer of the optical fiber to slide to a degree in contact with the yarn layer and thus reduces fatigue caused by axial movement of a ferrule of the connector terminating the optical fiber cable. On the other hand, if the buffer is relatively thick, a friction-reducing substance such as Modaflo.TM. can be applied to the optical fiber to allow the buffer to be stripped relatively easily. A zip-cord duplex optical fiber cable of this invention includes essentially two simplex optical fiber cables with their respective sheaths joining at a middle portion along the axial length of the simplex optical fiber cables. Thus, in cross-section, the zip-cord duplex optical fiber cable has a figure-eight shape with a relatively thin portion in the middle which can be manually pulled apart to separate the zip-cord duplex optical fiber cable into separate simplex optical fiber cables. This feature of the invention allows the zip-cord duplex optical fiber cable to be split at its ends to allow connectors attached to respective ends of the optical fiber cables for connection to respective spaced connector receptacles. A second duplex optical fiber cable of this invention includes two simplex optical fiber cables arranged side-by-side with an oversheath extruded about and holding together the two simplex optical fiber cables. In cross-section, the two duplex optical fiber cables of this invention are less than 2.0 mm in height and 4.0 mm in width, and thus are much smaller than currently available duplex optical fiber cables. The invention also includes die assemblies and methods for making the simplex and duplex optical fiber cables.

Sub-miniature optical fiber cables, and apparatuses and methods for

A buffered optical fiber (20) includes an optical fiber (21) comprising a core and a cladding. Typically, the optical fiber is enclosed by at least one layer (23) of coating material. The optical fiber is enclosed by a plastic buffer layer (30). Interposed between the optical fiber and the buffer layer is a boundary layer (40). Importantly, the boundary layer of the present invention is a low modulus material applied as a substantially thick layer relative to the buffer layer. In a preferred embodiment, the wall thickness of the boundary layer is about one-forth to one-third the wall thickness of the buffer layer. However, depending on the particular materials selected for the buffer and boundary layer, the wall thickness of the boundary layer can be as thin as one-twenty-fifth (1/25) of the buffer layer. As a result of the present design, there is sufficient adhesion between the buffer layer and the underlying coating material to maintain the buffer layer in place during normal use of the buffered optical fiber. On the other hand, the adhesion is low enough so that the buffer layer may be removed upon the application of reasonably low mechanical stripping forces. Advantageously, the boundary layer also allows the selective removal of the optical fiber coating material as well as the plastic buffer layer.

Buffered optical fiber having a strippable buffer layer

An optical fiber cable (20) includes a core (22) which includes a plurality of bundles (31, 31 ) of optical fiber (24) and a yarn-like strength member system (35) which is wrapped with an oscillated or unidirectional lay about the optical fibers. The strength member system also provides impact resistance for the fibers. A jacket (40) which may include a flame-resistant plastic material encloses the core with the outer diameter of the jacket being substantially less than that of typical optical fiber cables. Portions of the strength member system contact an inner surface of the jacket, an outer surface of which is the outer surface of the cable.

Utility optical fiber cable

An optical fiber cable (20) which is suitable for service from a distribution closure to a customer's premises includes a transmission media core (21) enclosed in a relatively rigid tubular member (40). The relatively rigid tubular member is enclosed in a jacket (44) comprising a plastic material which has a cut-through resistance which is substantially less than that of the tubular member. Interposed between the tubular member and an outer surface of the jacket is a strength member system comprising two yarn-like longitudinally extending strength member groups (52--52). The strength member grops are diametrically opposed to each other and are disposed in engagement with the tubular member.

Optical fiber service cable

An optical fiber cable particularly suited for use in building distribution systems includes a core which comprises a plurality of coated optical fibers (22--22) with each being enclosed in a plastic buffer (26). The optical fibers are individually or collectively enclosed in a fibrous strength member. Over the strength member in each of several embodiments is provided an outer jacket comprising a plastic material having excellent resistance to flame spread and smoke evolution. The plastic material comprising the jacket is disposed about the strength member and decoupled sufficiently therefrom to avoid the introduction of microbending stresses in the optical fiber. This may be accomplished by vacuum sizing the plastic material which has been tubed over an advancing optical fiber core as the plastic material is being drawn down onto the strength member.

Optical fiber plenum cable and methods of making

A method is disclosed for removing an end cap from a telecommunications cable wherein a circumferential incision and a plurality of longitudinal incisions are made with a wire in segmenting the cap.

Cable end cap removal method

A pressurizable closure is disclosed for a telecommunication cable. The closure has a metallic air valve extending through a closure to each end of which electrical couplers are secured for use in grounding the cable sheath.

Growing community of inventors

Lilburn, GA, United States of America

James Robert Holman