Abstract: Drawn optical fiber is provided with at least one layer of a coating material. The coating material typically is a UV curable material and provides the optical fiber with mechanical and environmental protection. It has been found that the temperature at which the optical fiber is cured has a pronounced effect on the modulus of the cured coating material. In order to provide a coated optical fiber of which the coating material has a desired modulus, the temperature of the coating material during cure is controlled by controlling the amount of energy of infrared wavelength which impinges on the coating material.

Abstract: A communications cable (20) comprising a core (22) of at least one transmission media and a plastic jacket (34) includes provisions for preventing the movement of water within the cable. The cable includes a strength system (32) including longitudinally extending fibrous strength members (32-33) having a relatively high modulus and having water blocking provisions. In one embodiment, each fibrous strength member is treated with a superabsorbent liquid material which when dry fills interstices and covers portions of the exterior thereof. In another embodiment, a filamentary strand material comprising a water swellable fibrous material is wrapped about each fibrous strength member.

Abstract: A communications cable comprising a core of transmission media such as optical fibers, for example, disposed in a core tube and a sheath system (32) includes provisions for preventing the movement of water within the cable core. Water blocking provisions (26) are disposed in the core tube and may comprise a tape or a yarn, for example, or both. The tape may comprise substrate tapes between which is disposed a superabsorbent material in powder form which upon contact with water swells and inhibits the further movement of the water. In another embodiment, a water swellable yarn may extend longitudinally linearly with the optical fibers in the core.

Abstract: Cordage (17) which may be used for any of the commonly marketed lengths of etractile cords comprises an array of a plurality of conductors (11--11) each insulated with a suitable plastic material. The array of conductors is enclosed in inner and outer jackets (52, 54). The inner jacket comprises a polyvinyl chloride (PVC) plastic material, for example, and has a thickness of about 0.015 inch. Covering the inner jacket is an outer jacket comprising a polyvinyl chloride plastic material having a thickness of about 0.005 inch and having a colorant constituent. The PVC composition of the inner jacket is such that it is a less expensive composition than that of the outer jacket. Enclosing the outer jacket is a layer (56) which comprises a top coating material. The top coating material provides the cordage with enhanced retractibility and prevents discoloration as well as plasticizer migration from the outer jacket.

Abstract: An optical fiber sensing system for detecting intrusion of optical fiber or optical fiber cables includes an interferometric arrangement. Two ports (28, 30) of a four port splitter (25) are connected to a source (26) of optical power such as a laser, for example, and to a detector (32). The other two ports (46, 48) are connected to ends of a length (50) of monitoring optical fiber. An input signal to the splitter is split with one subsignal being directed in one direction around the length of optical fiber which serves as a common path between the two ports. The other signal is caused to travel around the common path in an opposite direction. The split signals are recombined in the splitter and their phase difference measured as a detectable pattern by the detector. Should there be intrusion of the optical fiber or a cable containing the monitoring optical fiber, the pattern which is detected will change a significant amount.

Abstract: A biconic optical fiber connector (20) comprising two plugs (24--24) each having truncated conically shaped end portions (30--30) for terminating optical fibers to be connected and a sleeve (66) in which the plug eng portions are received is provided with an attenuator (70) which results in low reflected power. The attenuator comprises a plate-like element which is disposed between the plug end portions. Advantageously, the plugs are seated in the sleeve and the thickness and mounting of the attenuator cooperate to cause the plug ends to engage the attenuator when the plugs are seated in the sleeve cavities. Also, the attenuator is supported within the sleeve so that it is capable of slight movement in a direction parallel to a longitudinal axis (91) of the sleeve to self-adjust, if necessary, as the plug end portions are inserted and become seated in the sleeve.

Abstract: A bonded optical fiber array (20) includes a parallel coplanar array of longitudinally extending contacting optical fibers (22--22). Each optical fiber is enclosed in inner and outer layers of coating materials and is provided with a color identifier. The inner layer is comprised of a UV curable bonding material having a modulus in the range of about 1 M Pa. For mechanical protection, the outer layer is a UV curable bonding material having a modulus in the range of about 1 GPa. When the optical fibers are disposed in the parallel array, interstices are created between the fibers and between the fibers and an envelope which is spaced no further than about 25 .mu.m at its closest point to each fiber. A UV curable matrix bonding material which has a modulus having a value less than that of the outer coating layer on the fiber and more than that of the inner coating layer fills the interstices, extends to the peripheral line which defines the envelope and bonds together the optical fibers.

Abstract: A terminal block (20) includes a plurality of wells each having a protector 32) disposed therein and each having a bore which communicates with a U-shaped terminal (60) so that a portion of the protector extends through the bore into engagement with a bade (66) of the terminal. Tangs (68--68) of each terminal depend downwardly. Also, the terminal block includes a plurality of terminal posts (62--62) each having a spade (69) depending therefrom. A first plastic material (70) encapsulates the base and innermost portions of each U-shaped terminal and post. Individual conductors of a pair in a cable (50) extend to a depending tang of a terminal and to a tang of an associated terminal. A strap wire interconnects the other depending tang of each U-shaped terminal to a spade of an associated terminal post. A second plastic material encapsulates the wiring and the outermost portions of the U-shaped terminals and of the spades of the terminal posts.

Abstract: A coupling (20) for backplane connections of an optical fiber arrangement facilitates superbly alignment of optical fibers notwithstanding blind insertion of a portion of the arrangement. The coupling arrangement includes a housing (70) which has a first end portion (52) and a second end portion (49) and which is mounted in an opening of a panel (32) such that it floats and is capable of three dimensional adjustive movement to facilitate alignment of plugs which terminate optical fibers and which are inserted into opposite ends of a sleeve (84) disposed in the housing. A longitudinal movement of the coupling is facilitated by a compression spring (102) which is disposed about the housing between the backplane and a retaining member (104).

Abstract: Methods and apparatus are provided for applying a colorant material to the surface of a plastic insulation material which has been applied to an elongated material such as a metallic conductor (22) or an optical fiber which is being moved at any of a wide range of speeds along a path of travel. The colorant material is applied by nozzles which are staggered along the path of travel and which direct the colorant into engagement with the plastic insulation material at different radial directions. A first plurality of nozzles (46--46) each cause the colorant to be in a spray pattern (45) which is in the area of a plane. Advantageously, those nozzles cooperate to stabilize the conductor and prevent undulations thereof as the conductor is moved along its path of travel. A second plurality of nozzles (50--50) cause the colorant to be in a solid conical pattern (53).

Abstract: An animal-resistant optical fiber cable (20) includes a core (22) which comprises a transmission medium and a sheath system. The sheath system includes an outer jacket (65) and a dielectric armor (40) in the form of a shell. The shell comprises a plurality of longitudinally extending preformed segments (42--42) each having an arcuately shaped cross section transverse to a longitudinal axis of the cable and each comprising glass fibers embedded in a matrix material. Each of the segments covers less than half of the periphery of the core and, in a preferred embodiment, eight segments are used. Further, the shell segments are stranded helically about the core with longitudinal edge surfaces of adjacent segments being in engagement with each other. The shell segments not only provide rodent protection for the cable, but also they provide suitable tensile and compressive strength. Further, because the cable has an all-dielectric sheath system, it is inherently lightning, corrosion and EMP resistant.

Abstract: A cable (20) which is particularly suited to the transmission of substantially error-free data at relatively high rates over relatively long distances includes at least two pairs of individually insulated conductors (42--42). The pairs of individually insulated conductors are enclosed in a tubular member (51) comprising a plastic material. A metallic shield (54) may or may not enclose the tubular member, and in a preferred embodiment, a plastic jacket (58) is provided. The twist length of each pair of insulated conductors does not exceed a value equal to the product of about forty and the outer diameter of the plastic insulation. Further, the twist lengths among the conductor pairs are varied in accordance with a twist frequency scheme modulated by non-uniform increments of twist frequency.

Abstract: A connector body (26) which terminates at least one transmission medium includes on each side thereof a cantilevered arm (66) having a latching nub (70) projecting from a free end of the arm. A release cover (80) having a gripping portion (88) oriented toward a cable input end (32) of the connector body is mounted slidably on the connector body with the latching nubs of the arms each projecting through a window (90) in the cover. Conductors in the connector body are connected to conductors of another connector or of a device by inserting the connector body and release cover into a coupling (100) or into a receptacle. The latching nubs of the arms protrude into openings (106--106) provided in a housing (102) of the coupling to secure the connector body thereto. In order to withdraw the connector body from the coupling, a user moves the cover slidably along the connector body toward the cable input end.

Abstract: A waterproof cable having a filling material for filling voids in the cable which comprises a styrene-rubber diblock copolymer, a styrene-rubber-styrene triblock copolymer a paraffinic oil, a polybutene oil and a polyethylene wax. The cable is suitable for aerial use as well as underground use.

Abstract: A communications cable comprising a core of at least one transmission medium and a plastic jacket includes provisions for preventing the movement of water within the cable. An impregnated tape (35) is interposed between the core and the jacket and is wrapped about the core to form a longitudinal overlapped seam. The tape comprises a substrate tape (37) which is impregnated with a superabsorbent material which upon contact with water swells and inhibits the further movement of the water. The tape and its thickness are controlled so that the thickness is minimal while the tensile strength of the tape and its porosity prior to impregnation are optimized.

Abstract: Spliced end portions (30-30) of two optical fibers are recoated in a manner hich 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 a hermaphroditic connector (20), an optical fiber cable (24) extends through a cap (46) into a tapered passageway of a flanged bushing. Optical fibers extend through a bore in a wedge (65) having a truncated conical shape and being received in the bushing. Portions of non-metallic filamentary strength member (28) of the cable are captured between surfaces of a wall of the tapered passageway and the wedge which are substantially smooth to avoid damage to the strength members. Forces applied to the cable cause the wedge to be seated further in the bushing. The included angle between diametrically opposite lines on the wedge surface that lie in a plane passing through the longitudinal axis of the wedge enhances the locking features. The fibers also extend through a retention nut (70) which is turned threadably over a portion of the bushing and each fiber is connected to a plug (94) mounted adjacent to an end of the connector with one plug being received in an alignment sleeve (130).

Abstract: In an optical fiber connector (20), an alignment sleeve (66) for holding two conically shaped portions (30-30) of plug (24-24) of plug assemblies (22-22) each of which terminates an optical fiber (25) of a cable (35) includes two conically shaped cavities (68,70) communicating through a common plane (72). The conically shaped portion of each plug is urged toward the center of the sleeve by a spring (44). Each plug assembly at its cable entrance end is provided with an end retainer (80) having a central opening which is larger than the cross sectional area of the plug body but not of a retaining ring (42) disposed around the plug. When caps (46-46) of the plug assemblies are mounted and turned into a coupling housing (57) which encloses the sleeve and which is supported by a panel, the sleeve is maintained in a floating position under the urging of each plug. The sleeve together with the plugs therein is capable of movement prior to the occurrence of relative movement between one of the plugs and the sleeve.

Abstract: A cable (20) which may be used in an aerial or buried installation to serve customers' premises and which is a composite optical fiber-copper conductor type serves present customer needs but has the capability to fulfill the service requirements predicted in the communications market of tomorrow. The cable includes one or more reinforced optical fiber units (22--22) and one or more metallic conductor pairs enclosed in a sheath system. Each optical fiber unit is reinforced to include a plurality of strength members (40--40) arrayed about a buffered optical fiber (36) to enclose the optical fiber and to provide columnar strength to resist compressive forces. A filling compound (52) is disposed within the unit between a jacket (50) which encloses the strength members and the buffered optical fiber.