Abstract: It is disclosed an optical fibre unit for air-blown installations comprising: a first group of optical fibres embedded in a resin layer; a sheath arranged in a radially outer position with respect to the resin layer so that an annular space is formed between resin layer and sheath; and a second group of optical fibres arranged in the annular space. Also disclosed are an apparatus and a method for manufacturing such optical fibre unit.

Abstract: It is disclosed a method for coupling an optical fiber to a fiber optic cable, the fiber optic cable comprising a sheath surrounding an optical core comprising a buffer tube, the optical fiber being loosely contained in the buffer tube. The method comprises: cutting the sheath for a predetermined length thereof and exposing a corresponding portion of the optical core extending outward beyond a butt of the cut sheath; cutting the buffer tube of the exposed optical core and exposing a portion of the optical fiber; using a blocking tube to at least partially surround a section of the exposed portion of the optical fiber; and injecting a sealant into the blocking tube to lock the optical fiber within the blocking tube and couple the optical fiber to the fiber optic cable.

Abstract: A method of installing a cable through a duct by blowing the cable with a stream of compressed air. The method comprises dispersing a nebulized lubricant in the stream of compressed air, causing the stream of compressed air to deposit the nebulized lubricant onto the cable and to blow it into the duct. An apparatus for carrying out the method is also disclosed.

Abstract: It is disclosed a method for coupling an optical fiber to a fiber optic cable, the fiber optic cable comprising a sheath surrounding an optical core comprising a buffer tube, the optical fiber being loosely contained in the buffer tube. The method comprises: cutting the sheath for a predetermined length thereof and exposing a corresponding portion of the optical core extending outward beyond a butt of the cut sheath; cutting the buffer tube of the exposed optical core and exposing a portion of the optical fiber; using a blocking tube to at least partially surround a section of the exposed portion of the optical fiber; and injecting a sealant into the blocking tube to lock the optical fiber within the blocking tube and couple the optical fiber to the fiber optic cable.

Abstract: An optical cable comprising an optical core and an external sheath surrounding the optical core, wherein the external sheath comprises an inner layer circumferentially enclosing the optical core and an outer layer circumferentially enclosing the inner layer and comprising at least one longitudinal cavity accessible from outside the external sheath and extending through at least a portion of the outer layer thickness. The inner and outer layers of the external sheath are made of a first material having a first tensile strength, while the cavities in the outer layer are filled with a second material having a second tensile strength lower than the first tensile strength.

Abstract: An optical cable comprising an optical core and an external sheath surrounding the optical core, wherein the external sheath comprises an inner layer circumferentially enclosing the optical core and an outer layer circumferentially enclosing the inner layer and comprising at least one longitudinal cavity accessible from outside the external sheath and extending through at least a portion of the outer layer thickness. The inner and outer layers of the external sheath are made of a first material having a first tensile strength, while the cavities in the outer layer are filled with a second material having a second tensile strength lower than the first tensile strength.

Abstract: A method of installing a cable through a duct by blowing the cable with a stream of compressed air. The method comprises dispersing a nebulized lubricant in the stream of compressed air, causing the stream of compressed air to deposit the nebulized lubricant onto the cable and to blow it into the duct. An apparatus for carrying out the method is also disclosed.

Abstract: It is disclosed a cable assembly comprising a common figure-8 outer jacket comprising a first lobe and a second lobe, wherein the first lobe surrounds an electric core with a relevant first extruded inner sheath housing a strength member; and the second lobe surrounds an optical core with a relevant second extruded inner sheath.

Abstract: An optical fiber unit for air-blown installations includes a number of optical conductors, a first layer of resin material, a second layer of resin material radially outer to the first layer of resin material and a sheath of a thermoplastic material, wherein the second layer of resin material has a secant modulus higher than a secant modulus of the first layer of resin material and wherein the sheath of thermoplastic material is over and in close contact with the second layer of resin material.

Abstract: An optical cable includes an optical core and an external sheath surrounding the optical core. The external sheath includes a first material having a first, higher fracture toughness and a second material having a second, lower fracture toughness. The first and second materials are arranged so that the second, lower fracture toughness material is accessible from outside the cable along at least one longitudinally extending area of the sheath outer surface. For accessing the optical core of the cable, a short longitudinal cut, namely, few centimeters, is made with a blade in the accessible second, lower fracture toughness material. Then, its cut edges are pulled apart by hand. The pulling force causes the lower fracture toughness material to fracture, thereby propagating the initial short cut longitudinally along the sheath through its whole thickness.

Abstract: It is disclosed a cable assembly comprising a common figure-8 outer jacket comprising a first lobe and a second lobe, wherein the first lobe surrounds an electric core with a relevant first extruded inner sheath housing a strength member; and the second lobe surrounds an optical core with a relevant second extruded inner sheath.

Abstract: An optical fiber unit for air-blown installations includes a plurality of optical fiber sub-units and a central member, wherein the optical fiber sub-units are stranded around the central member; wherein each of the optical fiber sub-units includes a number of optical fibers, an inner layer which is radially outer to the optical fibers, and an outer layer which is radially outer to the inner layer, wherein the outer layer includes particulate material which is partially embedded into the outer layer; and wherein the optical fiber unit further includes a binder for keeping the stranded optical fiber sub-units in a proper arrangement.

Abstract: An optical cable includes an optical core and sheath enclosing the optical core. The optical core includes a number of optical units having respective colors and being wound about a longitudinal axis of the cable. The sheath includes at least one non opaque longitudinal section through which a sequence of colors of the optical units is visible from outside the cable. The color sequence acts as an identifier for the cable. The cable may therefore be easily identified (e.g. amongst other cables laid down within the same duct) by a simple visual inspection of the cable's inner structure through the non opaque section(s) of its external sheath.

Abstract: A telecommunication cable includes at least one optical fiber unit surrounded by a low fire hazard halogen free polymeric inner sheath that is covered by and in contact with a peelable, environmentally resistant polymer outer sheath. At least two discrete strength members are embedded into the low fire hazard halogen free polymeric inner sheath. The cable is intended for outdoor and indoor use.

Abstract: An optical fiber unit for air-blown installations includes a number of optical conductors, a first layer of resin material, a second layer of resin material radially outer to the first layer of resin material and a sheath of a thermoplastic material, wherein the second layer of resin material has a secant modulus higher than a secant modulus of the first layer of resin material and wherein the sheath of thermoplastic material is over and in close contact with the second layer of resin material.

Abstract: An optical fiber unit for air-blown installations includes a plurality of optical fiber sub-units and a central member, wherein the optical fiber sub-units are stranded around the central member; wherein each of the optical fiber sub-units includes a number of optical fibers, an inner layer which is radially outer to the optical fibers, and an outer layer which is radially outer to the inner layer, wherein the outer layer includes particulate material which is partially embedded into the outer layer; and wherein the optical fiber unit further includes a binder for keeping the stranded optical fiber sub-units in a proper arrangement.

Abstract: An optical cable includes an optical core and an external sheath surrounding the optical core. The external sheath includes a first material having a first, higher fracture toughness and a second material having a second, lower fracture toughness. The first and second materials are arranged so that the second, lower fracture toughness material is accessible from outside the cable along at least one longitudinally extending area of the sheath outer surface. For accessing the optical core of the cable, a short longitudinal cut, namely, few centimetres, is made with a blade in the accessible second, lower fracture toughness material. Then, its cut edges are pulled apart by hand. The pulling force causes the lower fracture toughness material to fracture, thereby propagating the initial short cut longitudinally along the sheath through its whole thickness.

Abstract: An optical cable includes an optical core and sheath enclosing the optical core. The optical core includes a number of optical units having respective colors and being wound about a longitudinal axis of the cable. The sheath includes at least one non opaque longitudinal section through which a sequence of colors of the optical units is visible from outside the cable. The color sequence acts as an identifier for the cable. The cable may therefore be easily identified (e.g. amongst other cables laid down within the same duct) by a simple visual inspection of the cable's inner structure through the non opaque section(s) of its external sheath.

Abstract: A telecommunication cable includes at least one optical fibre unit surrounded by a low fire hazard halogen free polymeric inner sheath that is covered by and in contact with a peelable, environmentally resistant polymer outer sheath. At least two discrete strength members are embedded into the low fire hazard halogen free polymeric inner sheath. The cable is intended for outdoor and indoor use.

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.