Abstract: A stack of optical fiber ribbons is enclosed in a buffer encasement having a relatively soft inner portion and an relatively hard outer portion. The inner portion has an interior surface extends around and defines a longitudinally extending passage that contains the stack, and the interior surface closely bounds the stack. The outer portion extends around, closely bounds and contacts the inner portion, and has a modulus of elasticity that is greater than the modulus of elasticity of the inner portion. In accordance with one example of the invention, the inner portion has an exterior surface that extends around and is spaced apart from the passage, and the outer portion has an interior surface that extends around, closely bounds, and engages the exterior surface of the inner portion, whereby the buffer encasement has multiple plies. In contrast, in accordance with another example of the invention, a surface is not defined between the inner portion and the outer portion.

Abstract: A fiber optic cable having a plurality of buffer tubes. Within at least one of the buffer tubes is a plurality of main fibers. Within the cable outer sheath, the main fibers are factory-spliced with optical splitters at predetermined distances. Distribution fibers are factory-spliced to the outputs of the optical splitters. The distribution fibers reside within distribution buffer tubes, and are available for access at substantially any location along the length of the fiber optic cable. A certain number of the distribution fibers from a particular optical splitter extend in an upstream direction of the fiber cable, and the remaining distribution fibers from that optical splitter extend in a downstream direction.

Abstract: A telecommunications cable element having a transmission element disposed in a buffer tube made from thermoplastic polyolefin elastomeric buffer material is disclosed. The polyolefin elastomeric buffer material has a modulus of elasticity below about 500 MPa at room temperature and a modulus of elasticity below about 1500 MPa at −40° C. Preferentially, the thermoplastic polyolefin elastomer material forming the buffer tube has an elongation to break below about 500% and a Melt Flow Index above about 3.

Abstract: An optical fiber cable is constituted by a cylindrical spacer having on its surface helical grooves reversing their direction at a given pitch in which a stack of ribbon optical fibers is received.

Abstract: A fiber optic cable (10) having a tube assembly (20) therein. Tube assembly (20) includes an optical fiber group (22) in a tube (21). Optical fiber group (22) comprises a medial optical fiber subgroup (23) and lateral optical fiber subgroups (24a,24b;25a,25b;26a,26b) adjacent thereto. Subgroups (24a,24b;25a,25b;26a,26b) define a step-like profile for maximizing optical fiber packing density of tube assembly (20) and/or defining a high fiber count cable (10). In an exemplary embodiment, fiber optic cable (10) can include strength assemblies (30) on opposing sides of tube assembly (20) for defining a preferential bend plane in fiber optic cable (10).

Abstract: A method of manufacturing a multi-ribbon optical fiber structure which contains optical fibers, and which can be separated into at least two optical fiber ribbons, said method including:a first step in which a multi-ribbon structure is formed, containing the optical fibers disposed side-by-side, mutually parallel, substantially in the same plane which defines the faces of the multi-ribbon structure, and embedded in a common matrix, by coating the fibers making up the multi-ribbon structure with at least one covering layer, and then by thermosetting the layer; anda second step in which at least one longitudinal score line is formed between two adjacent optical fibers, the score line comprising at least one score in the covering layer, extending parallel to the axis X of the optical fibers of the multi-ribbon structure, and situated in a plane that is perpendicular to the faces of the multi-ribbon structure, and that lies substantially midway between said adjacent optical fibers, the score line being formed by

Abstract: Optical cable comprising a reinforcing tube with diameter less than 7 mm, obtained from a metal strip gradually deformed until it assumes a final configuration with overlapping outer edges, at least one optical fiber arranged loosely in the tube, a water-blocking fluid occupying 75% of the useful internal area of the tube and a plastic sheath around the tube. The water-blocking fluid is deposited when the strip is curved with edges a predetermined distance apart.

Abstract: A mono-fiber type optical fiber cord comprising: a coated optical fiber which is an optical fiber with a fiber coat therearound, a synthetic resin coat having a substantially rectangular sectional surface for further covering the coated optical fiber, and a reinforcing member within the coat for coated optical fiber, wherein the reinforcing member is located along one of the shorter sides of the coat in the substantially parallel direction with the shorter sides in such a manner as to be embedded along the longitudinally extending direction of the coated optical fiber. An optical cord ribbon is formed by mutually bonding the longer sides of the adjacent substantially rectangular sectional surfaces of a plurality of the mono-fiber type optical fiber cords, and thereafter by coating the external surface of the thus aligned optical fiber cords by a bundling coating method.

Abstract: A fiber optic cable (10) includes a cable core (20) and a sheath section (40). Interstitial assemblies (30) are disposed between cable core (20) and sheath section (40, at least one of the interstitial assemblies (30) includes a ripcord (38). Ripcord (38) is operative, upon application of a sufficient outwardly directed pulling force, to rip a cable core binder (26) stranded around buffer tubes (23), water swellable tape (27), and a binder (29) stranded around tape (27). A craftsman need not use a cutting tool to cut binders (26,29) and/or tape (27) which saves time and avoids potential injury to the craftsman and inadvertent damage to buffer tubes or other cable components.

Abstract: A fiber optic cable (10) having a slotted rod (12) with grooves (22) formed therein. At least one groove includes a buffer tube (13) having a ribbon stack (14) supported in a tensile window position within buffer tube (13) by a water blocking material (15). Fiber optic cable (10) has an ample tensile window, whereby macrobending and microbending of optical fibers in the ribbon stacks (14) is minimized.

Abstract: Loose tube fiber optic cable containing a core of S-Z stranded strands comprising optical fibers having first and second alternatively repeating first and second sections, and a sheath circumscribing the core. The ROL transition points defined by the junctures of first and second strand sections along the length of the cable have been provided at an optimized reduced distance therebetween that is approximately 1/2 of the longitudinal length of the sheath entry window created during mid-span entry of the loose tube fiber optic cable. Thus, at least one (1) ROL transition point will be located within the sheath entry window during mid-span entry access to the cable, and most suitably either two (2) or three (3) ROL transition points will be located.

Abstract: An optical unit (5a, 5b) comprising a plurality of optical fibers (2) grouped together in a tube (3a, 3b) and optionally assembled into one or more ribbons inside tube. The tube (3a, 3b) has a Young's modulus less than 200 MPa and a Shore A hardness less than 90 at a temperature of approximately +20.degree. C. and a Young's modulus less than 2000 MPa at a temperature of approximately -40.degree. C. A fiber optic cable (10, 20) comprising at least one such optical unit (5a, 5b). Application of the cable to telecommunications.

Abstract: A fiber optic cable is provided with a thermal shield which consists (proceeding outward from the cable) of a temperature insulating layer of a foam plastic such as polyethylene, a plastic film wrap such as aluminized nylon, a metallic braid such as tinned copper and an outer jacket of plastic as additional temperature insulation and to facilitate pulling the cable. The film wrap and outer jacket are optional. For further shielding a second layer of foam plastic may be positioned outside the first metallic braid followed by a second plastic film wrap, a second metallic braid and an outer plastic jacket. If the shielded cable is near a source of heat, such as a hot water pipe or an air conditioning duct, the fiber optic cable temperature is uniform throughout its cross-section. Without the thermal shield instability of the signals in different fibers may occur because of heat differential.

Abstract: In an optical fiber cable, for effectively suppressing undesired radiant noise propagating in a reinforcing wire or generated from the reinforcing wire without providing an electromagnetic shielding member apart from the optical fiber cable, a buffer layer and an outer jacket of an LAP sheath covering the reinforcing wire being a tension member forming the optical fiber cable are constituted by composite magnetic bodies, respectively, composed of soft magnetic powder and organic binding agents. It is preferable that the soft magnetic powder is powder being essentially flat.

Abstract: A composite ribbon coupling cable includes a plurality of elongated strengthening elements made of a resilient springy material, a plurality of elongated communications elements disposed in alternating spaced apart relation with the elongated strengthening elements, an inner jacket of insulative material encapsulating the alternating strengthening elements and communications elements therewithin so as to dispose the encapsulated elements in a substantially common plane providing a substantially flat ribbon configuration, and an outer jacket of resilient wear-resistant protective material encapsulating the inner jacket of insulative material. The strengthening elements preferably are elongated bands of a spring metal whereas the communications elements preferably have fiber optic cores or copper cores. The inner jacket includes a pair of inner flat layers of insulative material disposed along and adhered to opposite sides of the alternating strengthening elements and communications elements.

Abstract: The invention relates to a method of preparing an improved cable and an improved optical fiber cable comprising a central reinforcement member and a plurality of loose tubes as laying elements, placed longitudinally around the central reinforcement member. The loose tubes comprising at least one or more optical fiber filaments. A gel filling material is contained in both the inner section as well as the outer section of the loose tubes. A layer encircling the assembly is selected from the group consisting of an aramide fiber layer, a fiber glass and combination thereof. At least one or more plastic cover is placed longitudinally over the fiber layer to support metal ribbons which are peripherally incorporated to the assembly and a second layer of plastic cover is placed over the metal ribbon.

Abstract: This method allows manufacture of an optical cable including optical fibers (1) placed in a protective sheath including two coaxial tubes (3, 5), of which the inner tube (3) which is made of plastic material, contains said fiber (1). The method consists in placing the fibers in the first tube (3) so that they have a certain overlength with respect to said tube. Then, the assembly (1, 2, 3) is surrounded by second tube (5). The second tube (5) is placed around the first tube (1) after obtaining the overlength, from a metal tape whose longitudinal edges are butted together progressive around the assembly while being fixed to each other, then the second tube (5) is shrunk against the first tube (3). A layer adhesive material (4) is preferably interposed between the two tubes (3, 5).

Abstract: In an optical fiber ribbon including a plurality of optical fibers arranged in a common plane in generally side-by-side relationship and surrounded by a layer of matrix material, at least one stress concentration is formed in the matrix material surrounding the optical fiber ribbon. The stress concentration extends along at least a portion of the ribbon parallel to a longitudinal axis of the ribbon and concentrates stress applied to the ribbon such that the matrix material easily separates at the stress concentration. Each stress concentration may be formed directly in the matrix material during its application on the optical fibers, or an abrasive surface may be applied to the fiber to form the stress concentration. Stress concentrations may formed on at least one extreme edge of the optical fiber ribbon such that the entire matrix material may be easily removed from a section of optical fiber ribbon at a desired ribbon access location.

Abstract: The telecommunications cable of the invention comprises optical fibers and stabilization fibers disposed in an envelope in such a manner as to ensure longitudinal coupling therewith, such that part of the force to which the cable is subjected is shared uniformly over the fibers.

Abstract: An optical drop cable-units cable comprising a plastic pipe and a plurality of strandless optical drop cable-units and held in the plastics pipe, in which a space factor(B.times.n/A).times.100(%).ltoreq.51%whereA: void cross-sectional area of the plastic pipe,B: a cross-sectional area of a single optical drop cable-unit, andn: number of optical drop cable-units.

Abstract: An optical fiber carrier (10) having at least one protective member comprising a buffer tube (20). Buffer tube (20) has a removable section (30) removal of which permits separation of the buffer tube for access to optical fibers (42) in the tube. Buffer tube (20) may include an optical fiber ribbon (41) with a removable section (50) for facilitating separation of a protective member (48).

Abstract: A low cost rugged sealed fiber optic cable furcation unit is provided. The urcation unit has an outer heat shrink tube which encloses a protective tube. Within the protective tube, a spacer/fiber guide is located along with a sealant material. When installed and sealed, the sealed furcation unit includes fiber ends and cables. The furcation unit allows loose tube fiber optic cables or tube ducts within Air Blown Fiber (AEF) cables to be furcated into multiple single fiber cables. The furcation unit is compatible with both 250 micrometer and 500 micrometer coated optical fibers. The furcation unit is also compatible with common single fiber optical connectors and splices.

Abstract: The present invention relates to an arrangement in a cable, especially a hydro electric control cable, which has a plurality of hydraulic tubes and electrical cables. In order to arrive at such an arrangement which allows for a required volume of service fluid while retaining an optimum minimum bending radius, the present invention suggests that the cable is designed as an umbilical (1, 101) with three centrally arranged tubes (2) in helical configuration which are surrounded by a ring of electrical cables and hydraulic tubes to allow for lower minimum bend radius (MBR).

Abstract: A low cost rugged sealed fiber optic cable furcation unit is provided. The urcation unit has an outer heat shrink tube which encloses a protective tube. Within the protective tube, a spacer/fiber guide is located along with a sealant material. When installed and sealed, the sealed furcation unit includes fiber ends and cables. The furcation unit allows loose tube fiber optic cables or tube ducts within Air Blown Fiber (ABF) cables to be furcated into multiple single fiber cables. The furcation unit is compatible with both 250 micrometer and 500 micrometer coated optical fibers. The furcation unit is also compatible with common single fiber optical connectors and splices.

Abstract: An optical fiber cable having a minimum bend radius and comprising at least one U-shaped carrier helically stranded about a coaxial rod having a central axis and including in its lateral peripheral surface at least one groove, said groove containing at least one optical fiber element, is characterized in that the maximum compressive force on said U-shaped carrier caused by bending the cable to its minimum bend radius is less than the minimum such force which could cause said U-shaped carrier to buckle toward said groove. A cable with 16-fiber ribbons containing 250 .mu.m outer diameter (OD) fibers may contain up to 3200 optical fibers. The cable cross-section packing density may be 2.13 fibers/mm.sup.2.

Abstract: The cable (1) comprises a plurality of optical fibre micro-modules (2) grouped together inside an external sheath (4). The external portion of the latter has four bosses (5) moulded integral therewith and which extend along the entire length of the cable and form, along the generating lines of the cable, four diametrically opposed ribs. These bosses, by creating a special arrangement for application to the cable of compressive forces, produce an improvement in crushing strength.

Abstract: An optical groundwire includes an organizer made of glass fibers held together in a matrix. A plurality of core tubes containing optical fibers are retained within the organizer. A plurality of conductors are wrapped about the organizer to form a sheath.

Abstract: An optical cable or optical cable element and a method of manufacturing the same. The cable or cable element includes a tubular jacket containing a single optical fiber and a layer of loose tensile strength fibers applied without an intended lay surrounding the optical fiber. The tension applied to the tensile strength fibers during manufacturing does not exceed the tension applied during manufacturing to the optical fiber.

Abstract: An elongated optical transmission element has a plurality of light waveguides which are continuously mechanically connected to one another in various planes to form a structure extending in a longitudinal direction so that the cohesion between waveguides is essentially obtained by connections on the inside of the structure. The structure can be used in an optical and/or electrical lead and is used in optical and/or electrical cables.

Abstract: The present invention relates to an optical unit for an optical fiber telecommunications cable, the unit comprising a tube of a plastics material in which at least one optical fiber is loosely received, wherein the thickness of said tube is less than or equal to 0.5 mm, and wherein said material has a modulus of elasticity less than 1500 MPa at 20.degree. C. and a stress/elongation curve without a yield point.

Abstract: An installation 10 comprising a line 12 extending between and suspended from a plurality of spaced apart aerial suspension locations 14 defines a passage for an optical fiber unit. The line comprises a plurality of elongate tensile resistant tubes 18 connected end-to-end by respective connectors 20. The line is secured to each suspension location by respective securing means 22 which are secured to said line at two spaced apart locations 28, 30 thereon such that the portion 26 of said line between these locations is untensioned and includes a connector 20. The securing means 22 is adapted to allow tensioning of the portion 26 of said line when the tensile load on the line adjacent thereto on either side of said suspension location reaches a first predetermined amount, and the connector 20 is adapted to cause the end-to-end connection of the tensile resistant tubes 18 connected thereby to break when the tensile load on said portion reaches a second predetermined amount.

Abstract: A core for use in a slot type optical cable has one or more regularly disposed slots. One or more ribbon fibers are stacked into each of the slots, each of the ribbon fibers having a plurality of optical fibers. A tensile strength member is disposed at a center of the core. Each of the slots has a convex bottom surface with a predetermined curvature so that voids between the ribbon fiber at the bottom of the stack and top of the convex bottom surface in each of the slots are formed on both sides of the convex bottom surface. The convex bottom surface is provided with curvature whose radius is equal to or less than a distance from the center of the core to edges defined by the convex bottom surface meeting the pair of side surfaces in each of the slots.

Abstract: Optical cable, including (a) at least a closed longitudinal housing containing at least an optical fiber and (b) an outer coating permeable to water, wherein there is a second longitudinal housing comprising a moisture-absorbing composition that after absorption of more than 50% by weight of water releases less than 5% by weight of water at 60.degree. C. in two hours.

Abstract: An optical fiber complex overhead line including a spacer formed with a plurality of helical grooves in its outer periphery extending along the axial direction, each helical groove shaped to be able to accommodate at least two bundles of multi-core type optical fiber in the width direction of the groove, at least two bundles of multi-core type optical fiber accommodated in each of the helical grooves, a protective optical fiber covering accommodating the spacer, and a plurality of conductor strands arranged around the protective optical fiber covering.

Abstract: A cable duct for protecting communication cable is provided, comprising an elongated body portion having a first end and a second end, the body portion further including a longitudinal axis extending between the first end and the second end; and at least two passageways formed completely through the body portion and extending substantially parallel to the longitudinal axis, each of the passageways having a cross sectional area sufficient to loosely contain at least one communication cable. The cable duct is constructed from a combination of materials including plastic and crumb rubber, preferably in a 1:1 composition, and includes a plurality of external ridges formed perpendicular to the longitudinal axis. The body portion further includes end connectors which are removably attachable to the first end and/or second end for connecting the cable duct to a second cable duct.

Abstract: An optical fiber cable includes optical fibers loosely housed within a buffer tube. The buffer tube includes an inner coating, an outer coating, or both inner and outer coatings of moisture-absorptive material. The moisture-absorptive material may be a mixture of a moisture-absorptive powder and a thermoplastic resin; or a thermally crosslinked polymer; or a mixture of a moisture-absorptive resin and a resin cured by ultraviolet light.

Abstract: A fiber optic micro cable (10) includes a jacket (14) applied over a core (12) structure. The core (12) includes at least one optical fiber (20) positioned between longitudinally extending structural strength members (17), the strength members and the optical fibers being embedded in a buffer material (24). The strength members and the optical fibers are positioned in a common plane thereby resulting in a generally flat or rectangular shaped cable. The buffer material is selected to provide good adhesion with the jacket and to have a low modules of elasticity to distribute external forces applied to the cable. The jacket material is selected to have good adhesion to the buffer material and to be a tough and abrasion resistant material to further protect the cable core. The jacket is fabricated so that there is slightly more jacket material in the area of the strength members to thereby provide an external profile of the jacket with protrusions in the areas of the strength members.

Abstract: The cable comprises at least one module (3) of fine conductors (1) each covered in a primary sheath (2), the conductors being wrapped in a supporting sheath (4) that provides mechanical coupling between the fine conductors (1), and the fine conductors (1) being coated in an oil (5) having viscosity lying in the range 100 cPo to 5,000 cPo.

Abstract: An optical fiber cable includes a central strength member 11 surrounded by a plurality of optical fiber containing tubes 20, the central strength member and tubes being encircled by a sheath 35. The optical fiber containing tubes have a generally frustum or truncated isosceles triangular shaped profile with the base 22 of the triangular shape having a curvature corresponding to the inside surface of the cable sheath and a top 24 (truncated edge or corner) of the triangle opposite and generally parallel to the base having a curvature corresponding to the outside diameter of the central strength member, the plurality of tubes being positioned adjacent to one another in a pie shape to thereby form a central channel within the cable for the central strength member. The truncated isosceles triangular shape of the tubes have a larger cross-sectional area within the tubes for carrying optical fiber cables. Additionally, the shape of the tubes provides improved resistance to compression of the cable.

Abstract: A water-tight optical fiber communications cable constructed without the use of a viscous water-blocking compound other than in the buffer tubes thereof. One or more water swellable yarns are helically wrapped around the central strength member to absorb any water which may be present in the interstices between the central strength member and the buffer tubes. Additionally, a water swellable tape is disposed between the core and the jacket of the cable to absorb water from the interstices between the buffer tubes and elements overlaying the core of the cable.

Abstract: An optical fiber cable comprises a stacked plurality of optical fiber ribbons each including a plurality of optical fibers disposed side by side in substantially the same plane and all embedded in a common covering or matrix of the ribbon. A protective outer sheath protects the cable against radial compression loads. Reinforcing members withstand traction loads applied to the cable, which further comprises filler members of a material based on reinforcing fibers and having a coefficient of expansion similar to that of the optical fibers embedded in a connecting matrix. The filler members occupy all or part of a volume delimited by the outside surface of the stacked ribbons and by the inside surface of the outer sheath so that the combination of the stack and the filler members has an external contour in cross-section that is substantially circular. The filler members protect the ribbons against radial and longitudinal loads applied to the cable and oppose contraction of the cable by more than 0.2%.

Abstract: An optical cable comprises a plurality of light waveguides which are arranged at least one group with a prescribed structure. The light waveguides will have different mechanical sensitivities, with the waveguides having a low mechanical sensitivity being in those regions of the structure which have elevated mechanical stressing occurring.

Abstract: A communication cable includes a plurality of strands that are interconnected by cross pieces which can be easily separated from each other such that each strand can be used as independent cables. At least one strand of the communication cable includes at least one electrical communication line and at least one optical communication line.

Abstract: A fiber optic cable according to the present invention includes at least one lengthwise extending channel surrounding an elongate central support member with each channel defining a channel axis. At least one optical fiber is positioned within each channel and has an average position offset in a direction generally radially inward from the channel axis toward the central support member at about room temperature. In one embodiment, the at least one channel is defined by one or more buffer tubes stranded about the central support member. In another embodiment, the at least one channel is defined by core having one or more lengthwise extending slots. The fiber optic cable may also include a protective jacket surrounding the central support member and the channel defining means. The optical fibers typically have a coefficient of thermal expansion less than the respective coefficient of thermal expansion of at least one of the protective jacket, the channel defining means and central support member.

Abstract: A loose tube optical fiber cable with SZ stranding in which the units receive two or more laminated multicase ribbons stranded toward a central member with the stranding direction reversed at specific intervals. These multicase ribbons are twisted in the same direction as the stranding of the tube units, and a reverse stranding angle of the tube units is selected to be a value within a specific scope.

Abstract: Optical fiber core including a plastic buffer tube loosely containing individual optical fibers or a plurality of coplanar fibers in a plastic ribbon, which fibers and ribbon are longer than the buffer tube, at least two flexible strength members of a tensile strength greater than the tensile strength of the tube and having a coefficient of expansion and contraction less than that of the tube, at the outer surface of the tube and an adhesive binding the strength members to the tube and/or a tape or cord under tension around the strength members to prevent slippage of the strength members with respect to the tube and to prevent buckling of the strength members when the core is subject to compressive forces. Also, an optical fiber cable containing such core.

Abstract: The present invention is a well logging cable including first conductor elements, each of the first elements consisting of a steel wire surrounded by copper strands and covered in an electrically insulating material, and at least one second conductor element including at least one optical fiber enclosed in a metal tube, copper strands surrounding the tube and the strands covered by the electrically insulating material. The first elements and the at least one second element are arranged in a central bundle. The second conductor element is positioned within the bundle so as to be helically wound around a central axis of the bundle. The bundle is surrounded by armor wires helically wound externally to the bundle.

Abstract: Supporting elements designed as independent profiles are provided between ribbon stacks of optical waveguide ribbons of an optical cable. The supporting elements contribute to positing securing of the ribbon stacks within the opposite table.

Abstract: An aerial self-supporting fiber optic cable includes a pair of longitudinal strength members extending along respective opposite sides of a core, and a jacket surrounding the core and strength members, wherein the jacket has a generally elliptical outer cross-sectional shape. A major transverse axis of the generally elliptical jacket is generally aligned with an imaginary line defined between the pair of longitudinal strength members. The cable core includes at least one elongate buffer tube and at least one optical fiber disposed within the buffer tube. The strength members has a predetermined tensile strength to support the fiber optic cable between adjacent vertical supports. The jacket may have a generally elliptical shape with an enlarged central lobe surrounding the core, and a pair of relatively smaller lobes on opposite sides of the central lobe and surrounding respective longitudinal strength members.

Abstract: Light, flexible tubes are placed around optical fibers extending from the end of a cable jacket. A water impervious plug encases the end of the cable jacket and a portion of the flexible tubes. Couplers are attached to the light waveguide terminal ends and the optical couplers and the plug are placed in an opto-electronic equipment closure. The assembly is designed for use with cable television system aerial closures.