Alcatel

Draka Comteq B.v.

Michael T Rossi

Nicholas V Nechitailo

Brian G Risch

Dean J Rattazzi

Matthew Soltis

Olaf Loy Storaasli

Vincent Bourget

Peter Lausch

George J Dallas

Aaron Kelly

A method and apparatus for determining and adjusting binder laylength during the process of manufacturing a selected fiber optic cable design. Specifically, a binder, having a distinguishing and physically detectable feature, is wrapped around fiber optic bundles or a buffer tube. A detection system detects the unique feature associated with the binder and thus creates a calculates a representative distance value. The distance value is calculated in relation the periodic spacing between two detected points on the physically detectable binder and is continuously monitored by a closed feedback loop. A computer receives status data from the closed feedback loop and compares the received data to a stored laylength parameter. In light of the comparison, an algorithm adjusts the binder head speed accordingly. This process repeats until the desired stored laylength is detected by the detection system.

Apparatus and method for on-line binder laylength measurement and adjustment

The present invention adds a gel-swellable layer in fiber optic cables to aid in protecting the fibers within the cable. The gel-swellable layer can be placed on the fibers, individual ribbons, stacks of ribbons and on the inner surface of tubes by various methods, such as co-extrusion, and can be cured by either heat curing or UV curing. The gel-swellable layers of this invention can be either smooth or textured. When the fibers are placed into the tubes and the tubes are filled with the water resistant gel, the gel-swellable layer absorbs some of the gel causing it to 'swell'. As a result of the 'swelling' a certain volume of gel is absorbed by the layer, thus reducing the capability of the gel to flow at elevated temperatures.

Gel-swellable layers on fibers, fiber ribbons and buffer tubes

The present invention provides a method for reducing and/or controlling the variations of excess fiber length along the length of reeled fiber optic buffer tubes during the manufacture of the buffer tubes. The present invention varies any number, or combination, of parameters during the manufacture of buffer tubes to achieve a substantially uniform excess fiber length along a reeled buffer tube. One embodiment of the inventive method uses monotonically decaying draw or take-up tension of the buffer tubes during winding, combined with a stiffness-compliant pad placed on the reel core to aid in providing a substantially uniform excess fiber length in the tube, while another embodiment uses a monotonically increasing angular speed of the reel in combination with the stiffness-compliant pad on the reel core. In yet another embodiment a pad is placed either periodically or continuously in the windings of the buffer tube to provide an absorbing layer for the residual stresses existing in the buffer tube as it is reeled and after the reeling is complete, combined with re-reeling the buffer tube onto a second reel after the buffer tube has cooled (after manufacture), where the pad is removed during the re-reeling process. Additionally, the present invention can have the layers of buffer tube separated with rigid, cylindrical panels separating the layers. The present inventive method also combines any, or all, of the above steps to aid in achieving a substantially uniform excess fiber length along the length of the reeled buffer tube.

Method and apparatus to reduce variation of excess fiber length in buffer tubes of fiber optic cables

A fiber optic cable with optical fibers stranded around a central strength member, and surrounded outer jacket made of a low coefficient of friction material and thinly constructed to show the profile of the stranded shape of the optical lines through the jacket, to thereby form a textured surface.

Optimized fiber optic cable suitable for microduct blown installation

A cable with a ripcord disposed in the webbed connection portion between the messenger portion and the communications portion of the cable, the ripcord allowing for easy separation of the messenger portion from the communications portion of the cable. The figure-8 cable with a ripcord allows for doing away with or minimizing the need to access the cable with pocket knives, box cutters, razor blades, scalpels and other tools of dangerous implementation, all of which enjoy various levels of imprecise results. The connection portion may have an internal or external weakened section to facilitate the separation.

Strippable cable

An optical fiber cable including a buffer tube wherein the optical unit is maintained in an axial center location of the buffer tube and protected from contact with an inner wall of the buffer tube. At least first and second gel layers are interposed between the buffer tube and the optical unit, wherein the first gel layer surrounds the optical unit, the second gel layer surrounds the first gel layer, and the first and second gel layers have different rheological properties. The inner gel layer may have a yield stress and a viscosity which are lower than a yield stress and a viscosity of the outer gel layer. The lower yield stress and viscosity of the inner gel layer serves to maintain the optical unit in an axial center position within the buffer tube and facilitates easy re-positioning of the optical unit to the axial center position when the buffer tube is flexed or bent. As a result, the optical unit may be maintained in a low stress state and stress-induced attenuation may be prevented.

Optical cable housing an optical unit surrounded by a plurality of gel layers

A fiber optic buffer tube containing fiber optic ribbons centrally located within the buffer tube and a gel compound surrounding the fiber optic ribbons. Disposed within the gel compound, between the walls of the buffer tube and the fiber optic ribbons are water swellable yarns and/or particles. The water swellable yarns and/or particles volumetrically expand when in contact with water that has penetrated the buffer tube. The water swellable yarns/particles also provide greater surface area which helps to hold gel compound, at elevated temperature, within the tube and thus to prevent the fiber optic ribbons from coming into contact with the walls of the buffer tube, thereby preventing signal attenuation problems.

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Maiden, NC, United States of America

Michael T Rossi