Nkf Kabel B.v.

Draka Comteq B.v.

Prysmian Netherlands B.v.

Willem Greven

Willem Griffioen

Arie Van Wingerden

Pieter Lock

Cornelis Van 't Hul

Frans Robbert Bakker

Maja Keijzer

Patrick Menno Versteeg

David F Hawkins

Gerard Plumettaz

Jan Wigger Jonker

Cornelis Van't Hul

Cornelis Van &prime;T Hul

Cornelus Van T'Hul

Cornelis Van T Hul

Thomas Pothof

Corenlius VAN'T Hul

Disclosed is an improved method and apparatus for installing a cable into cable guide tubing and the like. The method typically includes rotating a reel of cable guide tubing at least 360&#xb0; while, using compressed gas, feeding a cable, such as a plurality of microducts, into the cable guide tubing. The related apparatus includes a cable injection unit and a rotation coupling unit to facilitate the installation of cable (e.g., microducts) into the rotating cable guide tubing.

Method and device for installing cable into cable guide tubing

A cable is installed in a duct by means of blowing (and, optionally, synergetic pushing) and lubricating the cable during field installation. Lubricating the cable is done after the cable exits from the cable blowing equipment and hence takes place in a pressurized airflow passage. Lubricant supplied from an external reservoir drains into a pressurized lubricator space through which the cable moves. Foam-plugs seal the entrance and the exit of the lubricator space. The cable is wetted by the lubricant as it moves through the lubricator space, and excess lubricant is wiped by the foam plug, leaving only a thin film of lubricant on the cable as it moves out of the lubricator. In one embodiment, the lubricator is fitted with a single wiping member in the form of an annular plug of open cell foam material, and the cable passes through laterally opposite sections of the annular plug. The lubricator housing is formed in mating sections, and the internal lubricator is also formed in mating sections. The lubricator is integrated with cable blowing equipment in one embodiment. A bundle of guide tubes is lubricated in another embodiment.

Optical cable lubricator with reservoir

A cable is installed in a protective duct or guide tube by means of blowing (and, optionally, synergetic pushing) and lubricating the cable during installation. Lubricating the cable is done after the cable exits from the cable blowing equipment and hence takes place in a pressurized airflow passage. A hollow chamber filled with foam-plugs saturated with lubricant forms the cable lubricator. Lubricant is wiped onto the cable as it moves through the pressurized lubrication compartment. A portion of the airflow used for propelling the cable during blowing installation is bypassed around the lubricator and injected into the duct trajectory downstream of the lubricator.

Optical cable installation with cable lubricator

A method for installing branches in a protective ducting system in which guide tubes and cables have already been laid, wherein at a desired branch location in the protective duct, a splittable Y-branch connector with an inlet opening, an outlet opening and at least one branch opening is installed by cutting a short section from the duct at the desired branch point and exposing the guide tubes and cables, opening the splittable branch connector and arranging it around the exposed guide tubes and cables, and closing and securing the Y-branch connector with splittable coupling collars in such a manner that the inlet opening and the outlet opening engage in sealing manner over the respective cut ends of the existing duct, and the branch opening of the connector is secured by engagement of a branch stub around a branch duct through which a branch guide tube is laid.

Method of installing Y-branch splittable connector

A filling body is inserted together with a loose bundle of guide tubes during installation into the passage space of a protective duct, thus enlarging the bundle diameter (which reduces the buckling risk) and making crossing of the guide tubes impossible. The guide tubes are positioned along the outside of the filling body, providing access to the guide tubes during post-installation branching. The filling body may include radially projecting spacer ribs that separate the guide tubes, thereby preventing crossing movement and helical stranding. The guide tubes are thus constrained and carried along with the filling body in alignment with the spacer ribs, so that buckling, helical stranding and three-dimensional restrictions or tangles cannot occur.

Installation bundle with spacer

A cable is installed in a guide tube by means of blowing (and, optionally, synergetic pushing) and lubricating the cable during this installation. Lubricating the cable is done after the cable has passed the cable blowing equipment and hence takes place in a pressurized airflow passage. A hollow chamber filled with foam-plugs saturated with lubricant forms the cable lubricator. To avoid buckling, cable guide blocks are placed, which also divide the lubricator in different sub-chambers, each with its own foam-plug and content of lubricant. The airflow, needed to propel the cable during blowing, can bypass the lubricator.

A filling body is inserted together with a loose bundle of guide tubes during installation in an existing protective duct, thus enlarging the bundle diameter (which reduces the buckling risk) and making crossing of the guide tubes impossible. The guide tubes are positioned along the outside of the filling body, providing access to the guide tubes during post-installation branching. The filling body may include radially projecting spacer ribs that separate the guide tubes, thereby preventing crossing movement and helical stranding. The guide tubes are thus constrained and carried along with the filling body in alignment with the spacer ribs, so that buckling, helical stranding and three-dimensional restrictions or tangles cannot occur. The filling body may include a thin tubular sidewall enclosing a longitudinal airflow passage that may be pressurized during installation, and deformable when unpressurized, thus providing mechanical protection against damage of the protective duct after installation.

A cable straightener removes mini-bends from cable as it is unwound from a reel for installation in an underground duct, providing improved blowing performance for any cable with non-negligible stiffness and that exhibits reel-set or shape memory recovery, for example cables enclosed within small diameter tubular steel jackets, cables enclosed within aluminum laminated polymer sheets, and cables enclosed within hard polymer tubing. Residual stresses induced in such cables are reduced by first and second sets of straightener rollers prior to pushing/blowing installation.

Optical cable installation with mini-bend reduction

An existing protective duct contains a bundle of guide tubes through which fiber optic cables are run to customers at existing service locations. In order to run a cable to a new customer at a different service location, the duct is cut at a branch point and a short section of the duct is removed to expose the guide tubes. An unused guide tube is cut and serially connected to a branch guide tube leading to the new service location. The protective duct sidewall is restored at the branch point by a splittable Y-branch connector that includes complementary housing sections, an inlet opening, an outlet opening and at least one branch opening. Splittable coupling collars seal the branch connector housing sections around the respective cut end portions of the existing duct. The Y-branch connector also includes a branch stub that is sealed around the branch guide tube.

Y-branch splittable connector

Guide tubes are arranged in a loose bundle and are fed into an existing tubular conduit or protective duct by a powered tractor and are pulled through the duct by the volumetric flow of compressed air which is introduced into the inlet end of the duct. The guide tubes are pressurized and closed at their leading end and trailing end. The existing duct is open at both ends. When the filling degree of the guide tube bundle (sum of guide tube cross-sectional areas compared to that of channelization duct) is provided in the range of from about 30% to about 60%, blowing/pushing installation of the guide tube bundle is substantially trouble free, and the bundle of guide tubes can be installed in a flexible and efficient manner over relatively greater distances.

Growing community of inventors

Delfzijl, Netherlands

Willem Greven