Abstract: An optical fiber cable (20) includes provisions in a core thereof for preventing the flow of water longitudinally along the core and for preventing freezing of such water. The provisions for preventing freezing of water within the core, which could effect adversely the optical fibers, includes an antifreeze material. Each of two tapes may be impregnated with an antifreeze material such as propylene glycol, for example, and used to provide a laminate with a superabsorbent powder therebetween. Advantageously, the cable may have suitable flame retardance so that it may extend from an outside manhole to distribution points within a building.

Abstract: Short and long wavelength absorption losses contribute to loss at the operating wavelength of an optical fiber drawn from a preform. Excess losses over and above Rayleigh scattering losses have been attributed to conditions such as temperature and the speed during drawing. Typically, after optical fiber (21) is drawn from an optical preform in a furnace (23) wherein temperatures may be 2200.degree. C. or higher, the fiber is moved out of the furnace and immediately through ambient environment to other portions of a draw line such as, for example, measuring and coating apparatus. It has been found that these absorption losses may be reduced substantially by application of a magnetic field to the optical fiber after it has been drawn and prior to it being coated.

Abstract: Methods and apparatus are provided for providing an electrically matched pair (20) of insulated metallic conductors (21, 21). Insulation is applied to successive portions of a length of wire-like metallic conductor (22) after which a colorant material (37) is applied to the surface of a plastic insulation material of a first portion of the length of the metallic conductor which is being moved along a path of travel. Facilities are provided for shielding a supply of the colorant material from the moving insulated metallic conductor and for then exposing a second portion of the length of the insulated metallic conductor to a different colorant material. The insulation and the colorant materials and their disposition with respect to the insulation are such that the dielectric constant of one insulated metallic conductor of the pair is substantially equal to that of the other.

Abstract: A cable (20) includes a plurality of conductors (24) included in a core (22) enclosed in a sheath system. Voids between the conductors are filled by a mixture of a filling composition characterized by a styrene-rubber block copolymer having a styrene/rubber ratio of from 0.2 to 0.5, an ASTM Type 104A oil and polyethylene and a superabsorbent polymer material. The mixture has a viscosity in the range of about 400 cps at 88.degree. C. to 11 cps at 110.degree. C. and may be used to fill substantially voids in a cable comprising as many as 3000 pairs of insulated metallic conductors. The superabsorbent polymer is incorporated into the gel composition in a concentration of about 10 parts by weight to per 100 parts by weight of the filling mixture. A flooding material which comprises a mixture of a flooding composition and a superabsorbent polymer may be used to flood voids between layers of the sheath system.

Abstract: A closure includes an end plate assembly (20) which includes an inner and an outer endplate and between which is disposed a cable sheath gripping assembly (60). The cable sheath gripping assembly includes a housing (62) and a clamping portion (100) which cooperate to form two cable-receiving passageways. Each passageway is formed between two channels, one being formed in the base and one being formed in the clamping portion. Each channel is provided with a plurality of inwardly extending circumferential and axial ribs with the ribs cooperating to clamp a cable end portion extending therewith. The engagement of the ribs with the cable end portion under compressive engagement caused by the turning of a bolt 106 into threaded insert of the housing provides enhanced resistance to pullout and rotation of the cable end portion.

Abstract: Spliced end portions (30--30) of two optical fibers are recoated in a manner which results in the cross section of the spliced length of fiber transverse to a longitudinal axis thereof being substantially constant. This is accomplished without compromising the adhesion of a curable recoating material (51) to an adjacent original coating material (38). In order to provide such a recoated portion, original coating material which is removed to permit splicing is removed in such a manner as to leave a tapered portion (52) remaining on the end portion of each optical fiber. As a result, the interface between the recoating material and the original coating material is increased sufficiently to avoid having to overlap some of the recoating material with original coating material on adjacent portions of the fibers being spliced.

Abstract: In order to mount optical fiber connectors in a panel (22), the panel is provided with a plurality of openings in each of which is disposed a buildout system. Each buildout system includes a buildout block each having a portion disposed on a rear side of the panel and adapted to have an optical fiber connector assembled thereto. Any one of three buildout blocks may be used in order to receive a desired connector which may be an ST, SC, or FC connector. Secured through a latching arrangement to the portion of the buildout block on a front side of the panel is a buildout which may have any one of three configurations to accept any one of the three connectors. The latching arrangement between buildout block and buildout is the same for any combination of buildout block and buildout. As a result of the structure of the buildout system, a buildout and a buildout block may be selected to connect any combination of the connectors.

Abstract: An insulated conductor (20) for use in a communication cable which includes a filling material (30) includes a copper conductor (25) and a composite insulation system (27) comprising two concentric layers of insulation. An inner foam layer (28) of the insulation comprises a cellular plastic material (28) which includes a stabilizer system. An outer layer (29) of the insulation is referred to as a skin and comprises a stabilized solid plastic material. The stabilizer system in each of the cellular and solid layers includes a bifunctional portion that functions as an antioxidant and as a metal deactivator and that has a relatively high resistance to extraction. The level of the bifunctional portion of the stabilizer in the cellular material is substantially greater than that in the skin inasmuch as it has been found that the level of the stabilizer cellular layer contiguous to the copper wire determines the oxidation performance level of the composite insulation.

Abstract: An optical fiber package (15) includes a support surface such as a hub of a bobbin (17) for convolutions of a length of optical fiber. The optical fiber includes a light transmitting portion such as a core and a cladding with inner and outer layers of coating material disposed thereabout. The coating material comprises an ultraviolet light curable material. Disposed throughout the curable coating material of the outer layer is an adhesive constituent which after having been solidified by the exposure of the optical fiber to ultraviolet light energy and subsequent to the winding of the optical fiber into a package for use in high speed payout is subjected to heat treatment to cause the adhesive constituent of each convolution to become tacky and cause the convolutions to be tacked together. The adhesion between adjacent convolutions is less than that between inner and outer layers of the coating materials and that between the inner layer and the cladding.

Abstract: A hermetically sealed optical fiber cable (20) includes a core (21) comprising a plurality of optical fiber ribbons (22,22) disposed within a core tube (30) comprised of a high temperature resistant polymeric material. The core tube is disposed within a hermetic sealing member (40) which comprises a metal of low electrochemical activity having a sealed seam. An outer jacket (50) is disposed about the hermetic sealing member. The core may be filled with a waterblocking filling material (35). The material of the core tube undergoes only limited degradation because of the limited amount of oxygen and/or moisture trapped in the hermetically sealed cable. The filling material and/or other materials of the cable scavenge moisture and oxygen which travel longitudinally of the cable and reach portions of the cable subjected to a high temperature because of a leak in an adjacent steam line.

Abstract: An optical fiber (24), destined to receive a hermetic coating (32), is moved through a hermetic coating apparatus (30) wherein the fiber, entering the hermetic coating apparatus as a predetermined temperature, is caused to be engaged by a reactive gas. The reactive gas, reacting with the heated fiber, is effective to cause a layer of a hermetic material to be deposited adjacent to the outer surface of the fiber. A cross-flow purge gas is effective to prevent a resultant accumulation of a soot comprising reactive components of the reactive gas adjacent to portions of the hermetic coating apparatus which become heated by the fiber. Failure to prevent the accumulation of the soot may lead to fiber abrasions and reduced fiber strength.

Abstract: A patch panel which includes an array of connectors includes a panel plate (22) having an array of openings (24,24) formed therein. Each opening is capable of receiving an adapter (30) which may be made of a plastic material and which includes opposed depressible cantilevered beams. Each adapter on opposed top and bottom surfaces of the arms includes two wedge-shaped tabs which cooperate with depending portions of sidewalls of the adapter to secure the adapter to the panel plate. Opposed grooves (55,55) open to internal sidewall surfaces and terminate in bridge portions (58,58) adjacent to a rear of the adapter. Each groove is adapted to receive a resilient tab (68) formed in a sidewall of a connector (60) or detent member (97) of a collar (80) to be received in the adapter.

Abstract: Optical fiber (20) which may be disposed in the form of a ribbon (28,30), for example, is caused to become disposed in a conduit (42) such as a duct which may exist in the field by introducing the optical fiber and a pressurized liquid transporting medium (37) into the conduit. The liquid transporting medium is effective to cause the optical fiber to be moved along in the conduit to cause a leading end of the fiber to emerge from a far end of the conduit and be accessible for connective arrangements, for example.

Abstract: An optical fiber cable (20) includes a longitudinally extending copper core member (34). The core member is formed with at least one groove (36) in which is disposed at least one optical fiber. The optical fiber is coupled sufficiently to the core member preferably by an ultraviolet light energy cured material to substantially inhibit relative movement between the optical fiber and the core member when forces are applied to the cable. A sheath system which includes a plastic jacket (112) is disposed about the core member. The sheath system includes a strength member system which includes longitudinally extending copper wires (105, 105) and steel wires (101, 107). Disposed about the steel and copper wires is a steel shield (110) which provides hermetic protection for the optical fibers.

Abstract: An optical fiber cable (20) includes a longitudinally extending core member (34) which may be made of a plastic material. The core member is formed with at least one groove (36) in which is disposed at least one optical fiber (28). The optical fiber is coupled sufficiently to the core member, preferably by an ultraviolet light energy cured material, to inhibit substantially relative movement between the core member and the optical fiber when forces are applied to the cable. A sheath system which includes wire-like strength members and a plastic jacket (112) is disposed about the core member. A waterblocking material (108) disposed within interstices among the wire-like strength members and between an inner layer of the strength members and the core member causes coupling between the wire-like strength members and the core member.

Abstract: In the manufacture of coated optical fiber, fiber (21) is drawn from a preform (22) and is coated with one or preferably two layers (42,44) of light curable coating materials. Afterwards, the coating materials are cured. Increases in manufacturing line speed may be achieved if the cure speed of the coating materials is increased. This is accomplished by the simultaneous application of a magnetic field during irradiation of the curable coating materials to enhance the crosslinking of the coating materials by a free radical polymerization mechanism. Upon absorption of light, a photoinitiator in each composition cleaves to produce two free radical fragments in the spin paired or singlet state. The magnetic field has the effect of enhancing the production of spin parallel radicals which enhances the polymerization initiation of the coating material, thereby allowing an increase in the manufacturing line speed through drawing and coating apparatus.

Abstract: An optical connector (20) includes a ferrule assembly (22) which is adapted to be received in a plug frame (70). The ferrule assembly is held in the plug frame by a cable retention assembly (40) which is adapted to be secured to said plug frame. A leading end of the plug frame is symmetrical in an end cross-section which is normal to a longitudinal axis of the connector. After the ferrule assembly has been assembled to the plug frame, the direction of any eccentricity of the plug passageway or of an optical fiber terminated by the ferrule assembly is determined. Then the plug frame is assembled to a housing of a grip (90) such that the direction of eccentricity is aligned with a key (92) of the grip. The plug frame is capable of being assembled to the grip notwithstanding the rotational orientation of the plug frame with respect to the grip.

Abstract: A cover (56) of an existing manhole is raised in elevation to the elevation of roadway resurfacing, for example, by an adapter (20) which is secured to a head ring (40) of the existing manhole. The adapter is such that when it is secured to the head ring, apertures (77--77) of ledges (75--75) of the adapter may be aligned with threaded apertures (59--59) in lugs of the head ring to which the cover had been secured. Spaced above the ledges and extending peripherally above the head ring is a lip (72) for supporting the cover. At ninety degrees to each of the ledges and projecting from the lip is an ear portion (84) to which the cover may be secured. Additional adapters may be secured to the first adapter which has been secured to the head ring prior to subsequent resurfacing operations.

Abstract: An optical fiber cable closure (20) includes a cable termination assembly (22) and a cover (23) into which the termination assembly is inserted. The cable termination assembly includes two spaced end plates (34,36) through which cables (28,29) to be spliced extend. One of the end plates supports a frame (101) which supports a plurality of optical fiber splicing trays (120--120). Adjacent end portions of the trays are staggered and hinged so that some trays may be moved pivotally to expose others. Optical fibers from each incoming cable are routed in individual tubes (115--115) or as ribbons from an optical fiber breakout (110) mounted in the frame to selected ones of the trays. Hinge lock plates (130--130) which complete a hinge for each tray also serve to clamp the tubes incoming to each tray to prevent unintended movement. Each of the trays may be provided with a plurality of organizing modules (140,140) each of which is adapted to hold a plurality of optical fiber connective devices.

Abstract: A closure (20) includes a grommet (50) having passageways (52-52) therethrough for allowing cables to extend into the closure. The grommet (50) comprises a unitary elastomeric body (60). Each passageway is defined by an interior sidewall from which a plurality of longitudinally spaced circumferential ridges (74-74) extend. For a substantial portion its circumference, each ridge has an axis of projection which forms an oblique angle with respect to a longitudinal axis of the associated passageway and is sufficiently elongated in longitudinal cross section so as to be capable of flexing with respect to the axis of projection during insertion of a portion of a cable and enlarging its opening diameter to accommodate and form a seal about the inserted cable portion.