Abstract: An optical cable includes a buffer tube housing at least one optical fiber, a sheath surrounding such buffer tube and at least one longitudinal strength member embedded in the sheath, in which at least one separation element is provided between a portion of the outer surface of the buffer tube and the inner surface of the sheath, laying in an axial plane not containing the at least one strength member.

Abstract: An optical fiber drop cable for suspension installation includes electrical conductors and at least one optical fiber. An electrically non-conductive reinforcing sleeve houses the conductors and the or each optical fiber. The reinforcing sleeve is housed in sheathing. In addition to or instead of the optical fiber or optical fibers, the reinforcing sleeve may house one or more elongate containers, preferably plastic tubes, for housing optical fibers.

Abstract: A method of determining the position of a blockage (192, 392) in a passage (15, 313) having a first end and a second end. The method comprises blowing a sealing device (200) into the passage to form a seal adjacent the blockage (192, 392), then blowing a gas into the passage from the first end, making at least one measurement concerning the gas blown into the passage from the first end and determining a distance D between the first end and the sealing device using the at least one measurement.

Abstract: An optical fiber unit having a sheath and a plurality of optical fiber elements loosely housed in the sheath. The sheath is coated with particles of an adherence reducing substance and has a radial thickness that is not substantially greater than 0.3 mm. The coating of adherence reducing particles is applied as a liquid coating. The liquid coating is a dispersion of the particles and heat is applied to evaporate the liquid content of the liquid coating to produce a dry coating of particles on the sheath.

Abstract: An optical fibre installation includes (i) a part defining an inlet for optical fibres that has a through-hole for the passage of optical fibres and an associated mating region for a push-fit connector, (ii) an optical fibre cable connected to an adapter that defines a connection region having a predetermined cross-section for mating with a push-fit connector and (iii) a push-fit connector having a first end, a second end, a through-passage extending between those ends and a seal associated with the first end. The second end of the push-fit connector is push-fit connected to the connection region of the adapter and the first end of the push-fit connector is push-fit connected with the mating region of the inlets in such a way that the seal sealingly engages the inlet defining part. The arrangement is such that optical fibres from the optical fibre cable can be directed through the push-fit connector and the through-hold of the inlet.

Abstract: A method of determining the position of a blockage (192, 392) in a passage (15, 313) having a first end and a second end. The method comprises blowing a sealing device (200) into the passage to form a seal adjacent the blockage (192, 392), then blowing a gas into the passage from the first end, making at least one measurement concerning the gas blown into the passage from the first end and determining a distance D between the first end and the sealing device using the at least one measurement.

Abstract: An optical fibre installation includes (i) a part defining an inlet for optical fibres that has a through-hole for the passage of optical fibres and an associated mating region for a push-fit connector, (ii) an optical fibre cable connected to an adapter that defines a connection region having a predetermined cross-section for mating with a push-fit connector and (iii) a push-fit connector having a first end, a second end, a through-passage extending between those ends and a seal associated with the first end. The second end of the push-fit connector is push-fit connected to the connection region of the adapter and the first end of the push-fit connector is push-fit connected with the mating region of the inlets in such a way that the seal sealingly engages the inlet defining part. The arrangement is such that optical fibres from the optical fibre cable can be directed through the push-fit connector and the through-hold of the inlet.

Abstract: An apparatus (12) is provided for use in determining a length at least representative of the length of a tube that defines a passage in an optical fibre cable (10) along which an optical fibre unit can be installed by blowing. The apparatus (12) comprises a pressure reservoir (32) in which a gas at a known pressure can be stored, outlet piping (34) connected with the pressure reservoir (32) and having an outlet end spaced from the reservoir for connection to a tube of the optical fibre cable (10). The apparatus has a pressure detecting arrangement (42) for detecting gas pressure in a tube connected with the outlet end of the outlet piping (34).

Abstract: A method of determining a length Ld at least representative of the length of a passage along which an optical unit or cable is to be installed by blowing, comprises the steps of flowing a pressurised gas into the passage at a substantially constant pressure P1 and substantially constant flow rate Vf until gas pressure within the passage reaches a predetermined level P2. The time period tf during which the pressurised gas was flowed into the passage is determined and then the length Ld is determined by reference to the time period tf.

Abstract: An optical fiber assembly includes: a component defining at least one inlet for optical fibers, an adapter, an optical fiber cable connected to the adapter, and a push-fit connector. The component includes a through-hole for passage of the optical fibers and an associated mating region to engage the push-fit connector. The optical fiber cable connected to the adapter defines a connection region with a predetermined cross-sectional shape for mating with the push-fit connector. The push-fit connector includes a first end, a second end, and a through-passage extending between the first and second ends. The first end is push-fit connected with the mating region. The second end is push-fit connected to the connection region. Optical fibers from the optical fiber cable can be directed through the push-fit connector and the through-hole. A method of installing optical fibers in a joint housing is also disclosed.

Abstract: An optical fibre unit having a sheath and a plurality of optical fibre elements loosely housed in the sheath. The sheath is coated with particles of an adherence reducing substance and has a radial thickness that is not substantially greater than 0.3 mm. The coating of adherence reducing particles is applied as a liquid coating. The liquid coating is a dispersion of the particles and heat is applied to evaporate the liquid content of the liquid coating to produce a dry coating of particles on the sheath.

Abstract: The apparatus has a feed mechanism engageable with the optical fibre cable for feeding the cable toward the duct, a mechanism for directing a gaseous flow into the duct for propelling the optical fibre cable along the duct and a drying mechanism disposed upstream of the cable feed device for removing moisture that may be present on an exterior surface of the duct.

Abstract: An optical fibre drop cable for suspension installation includes sheathing having a first portion containing a strengthening arrangement for supporting the cable in a suspension installation and a second portion that is separable from the first portion. The second sheathing portion contains a plurality of electrical conductors. The first sheathing portion defines at least one passage for optical fibers.

Abstract: An aerial cable installation having an aerial cable suspended from a suspension point through a suspension device. This device has a clamp having two saddle members engaging the cable on diametrically opposite sides thereof and a plurality of nut and bolt assemblies extending through aligned holes in flanges of said saddle members for resiliently biasing the saddle members toward each other to clamp against the cable with a selected clamping force. To this end, each nut and bolt assembly includes a helical spring mounted on the bolt thereof between said flanges and the nut of the assembly and the springs are compressed a predetermined amout which is adjustable by tightening or loosening said assemblies.

Abstract: A method of determining a length Ld at least representative of the length of a passage along which an optical unit or cable is to be installed by blowing, comprises the steps of flowing a pressurised gas into the passage at a substantially constant pressure P1 and substantially constant flow rate Vf until gas pressure within the passage reaches a predetermined level P2. The time period tf during which the pressurised gas was flowed into the passage is determined and then the length Ld is determined by reference to the time period tf.

Abstract: An optical fibre unit having a sheath and a plurality of optical fibre elements loosely housed in the sheath. The sheath is coated with particles of an adherence reducing substance and has a radial thickness that is not substantially greater than 0.3 mm. The coating of adherence reducing particles is applied as a liquid coating. The liquid coating is a dispersion of the particles and heat is applied to evaporate the liquid content of the liquid coating to produce a dry coating of particles on the sheath.

Abstract: An optical fiber cable for blown installation has a tubular central strength member about which tubes loosely housing optical fibers are stranded. The jacket is preferably formed from a high density polyethylene material and is extruded over the core on which rip cords are positioned. A water blocking compound is provided in each tube in any spaces therein which would otherwise be void. Also a water blocking material is provided between the sheath and the layer defined by the helically wound wrapping tape or binding yam in any spaces between the tubes which would otherwise be void.

Abstract: An optical fibre drop cable for suspension installation includes sheathing having a first portion containing a strengthening arrangement for supporting the cable in a suspension installation and a second portion that is separable from the first portion. The second sheathing portion contains a plurality of electrical conductors. The first sheathing portion defines at least one passage for optical fibres.

Abstract: An optical fibre drop cable for suspension installation includes electrical conductors and at least one optical fibre. An electrically non-conductive reinforcing sleeve houses the conductors and the or each optical fibre. The reinforcing sleeve is housed in sheathing. In addition to or instead of the optical fibre or optical fibres, the reinforcing sleeve may house one or more elongate containers, preferably plastic tubes, for housing optical fibres.

Abstract: An optical fibre installation includes (i) a part defining an inlet for optical fibres that has a through-hole for the passage of optical fibres and an associated mating region for a push-fit connector, (ii) an optical fibre cable connected to an adapter that defines a connection region having a predetermined cross-section for mating with a push-fit connector and (iii) a push-fit connector having a first end, a second end, a through-passage extending between those ends and a seal associated with the first end. The second end of the push-fit connector is push-fit connected to the connection region of the adapter and the first end of the push-fit connector is push-fit connected with the mating region of the inlets in such a way that the seal sealingly engages the inlet defining part. The arrangement is such that optical fibres from the optical fibre cable can be directed through the push-fit connector and the through-hold of the inlet.