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 (33--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: 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: A communications cable for use in buried environments in an outside plant includes a core (22) comprising at least one transmission medium and a mechanically strengthened, thermal resistant barrier layer (40) disposed about a plastic tubular member (23). A metallic shield (32) and a plastic jacket (36) are disposed about the barrier. The barrier layer may comprise a tape (41) which is made of a material such as woven glass or an aramid fibrous material, for example, which is resistant to relatively high temperatures, which has suitable strength properties in all directions and at elevated temperatures and which is characterized by properties which cause the barrier layer to impede the passage therethrough of particles which are sufficiently large to cause damage to the core. In a preferred embodiment, the thermal barrier layer also includes provisions for preventing the longitudinal flow of water within the cable.

Abstract: An optical fiber cable (20) ideally suited for aerial distribution use, for example, includes in a preferred embodiment at least one bundle (23) of optical fibers (25--25). The at least one bundle is disposed in a tubular member (30) which is made of a plastic material suitable for use in a relatively wide temperature range and which is enclosed by a sheath system (32). A predetermined excess length of fiber is caused to be disposed in the tubular member. The excess length of each fiber is such that it is sufficient to avoid undue strains on the fiber as the cable core is exposed to the elements and to forces imparted during handling such as during installation. On the other hand, the excess fiber length must not be so great as to result in undue curvature of the fiber or excessive interactive engagement of the fiber with an inner wall of the tubular member.

Abstract: A totally dielectric cable includes a core (21) comprising a plurality of optical fiber transmission media (24--24). The core is enclosed by a core tube (34) which is made of a plastic material and water blocking provisions are provided within the core tube for preventing the longitudinal migration of water. A water blocking tape (44) may be provided in engagement with an outer surface of the core tube and a plastic jacket is extruded thereover. Interposed between the outer surface of the jacket and the core tube are two diametrically opposed pluralities (60--60) of strength members each of which may be made of glass fibers. At least one strength member (62) of each plurality is rod-like to provide compressive as well as tensile strength for the cable. The remaining strength members of each plurality are relatively flexible rovings (64--64) which supplement the tensile strength of the rod-like members.

Abstract: An optical fiber cable (20) includes a core (21) comprising a plurality of optical fibers (24--24) without intended stranding. The plurality of optical fibers are enclosed in a common tube (34) which provides a predetermined packing density and which is substantially parallel to the longitudinal axis of the cable. In one embodiment, a waterblocking material (36) is disposed within the tube to fill the interstices between the optical fibers and between the fibers and the tube. The waterblocking material is such that its critical yield stress does not exceed about 70 Pa at 20.degree. C. and such that it has a shear modulus of less than about 13 KPa at 20.degree. C. The common tube is enclosed with non-metallic or metallic strength members and a plastic inner jacket and by another layer of strength members and by a plastic outer jacket.

Abstract: An optical fiber cable core (20) which is sold to a cable manufacturer for oversheathing or for incorporation into electrical power aerial cables, for example, includes in a preferred embodiment at least one bundle (23) of optical fibers (25--25). The at least one bundle is disposed in a tubular member (30) which is made of a plastic material suitable for use in relatively wide temperature range. The core is manufactured to cause a predetermined excess length of fiber to be disposed in the tubular member. The excess length of each fiber is such that it is sufficient to avoid undue strains on the fiber as the cable core is exposed to the elements and to forces imparted during handling such as during installation. On the other hand, the excess fiber length must not be so great as to result in undue curvature of the fiber or excessive interactive engagement of the fiber with an inner wall of the tubular member.

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 a cross section transverse to a longitudinal axis of the cable each of which covers less than half of the periphery of the core. Further, the shell segments are stranded helically about the core with at least portions of longitudinal edge surfaces of adjacent segments being in engagement with each other. The shell segments not only provide rodent protecting for the cable, but also they provide suitable tensile and compressive strength. Further, because the cable in the preferred embodiment has an all-dielectric sheath system, it is inherently lightning, corrosion and EMP resistant.

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 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: An optical fiber cable (20) which may be used in a high temperature environment for a substantial period of time without degradation of transmission includes an optical fiber core (22) which is enclosed by an inner tubular member (32) having suitable temperature resistant properties. A braided metallic outer tubular member (50) encloses the inner tubular member and provides suitable mechanical protection and strength for the cable. The integrity of the cable and its performance is further enhanced by a corrugated metallic tube having a sealed periphery and being interposed between the inner and outer tubular members to prevent the ingress of liquid contaminants and to provide the cable with flexibility.

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: An optical fiber cable (20) includes a core (21) comprising plurality of units (22--22). Each unit is formed by a plurality of optical fibers (24--24) which are assembled together without intended stranding. Each of the optical fibers includes a core, and inner and outer claddings with the inner cladding characterized by an index of refraction depressed from that of the outer cladding. The ratio of the inner cladding diameter to the core diameter and the ratio of the difference in the indices of refraction of the inner and outer claddings to the difference in indices of refraction between the core and the inner cladding are such that each optical fiber is capable of operation in a single mode fashion at a predetermined wavelength. Also, the difference between the indices of refraction of the core and the inner cladding is sufficiently high to cause each fiber to be substantially insensitive to microbending.

Abstract: An optical fiber cable (20) includes a core (21) comprising a plurality of units (22--22). Each unit is formed by a plurality of optical fibers (24--24) which are assembled together without intended stranding. The plurality of units are enclosed in a common tube (34) which provides a predetermined packing density and which is substantially parallel to the longitudinal axis of the cable. In one embodiment, a waterblocking material (36) is disposed within the tube to fill the interstices between the optical fibers and between the units. The waterblocking material is such that its critical yield stress does not exceed about 70 Pa at 20.degree. C. and such that it has a shear modulus of less than about 13 KPa at 20.degree. C. The common tube is enclosed with non-metallic or metallic strength members and a plastic inner jacket and by another layer of strength members and by a plastic outer jacket.

Abstract: An optical fiber cable (20) includes a core (22) comprising at least one optical fiber (23) which is enclosed in a tubular member (28) and which includes a non-metallic sheath system (30). The sheath system includes two contiguous layers (40, 50) of non-metallic strength members which extend longitudinally along the cable and which are wrapped helically in opposite directions about the tubular member. The layers of strength members are enclosed in a plastic jacket (36). At least some of the strength members which are capable of withstanding expected compressive as well as tensile loading are coupled sufficiently to the jacket to provide a composite arrangement which is effective to inhibit contraction. Those strength members cooperate with the remaining strength members to provide the cable with a predetermined tensile stiffness and to cause the cable to be relatively flexible.

Abstract: Compressive strain in cabled optical fibers can cause buckling of the fibers and resulting microbending loss. To measure the longitudinal compression in cabled optical fibers, a modulated laser beam is directed through a first fiber and looped back to the origin by a second fiber. Next, the cable is stretched until tensile strain is indicated by a change in phase of the modulated signal. The amount of stretching required indicates the degree of compression on the fibers in the unstretched cable, and hence the amount of excess length of fiber in the cable. To measure excess fiber in relatively long lengths of cable, a portion of the cable can remain reeled, and the strain applied to the unreeled portion. A correction factor can be determined for slippage between the fiber and sheath in the reeled portion.

Abstract: Multifilament bundles are impregnated with an ultraviolet curable resin to form a composite material suitable for use as a strength member in cables and other applications. The inventive coatings obtain good wetting of the filaments, allowing rapid penetration into the roving or yarn. A much faster coating and curing operation is obtained as compared to prior art methods. Fiberglass strength members made by this technique are especially advantageous for use in optical fiber cables where high strength and a low thermal coefficient of expansion are desired, as well as nonconductivity to protect against lightning strikes.

Abstract: A heat conducting and radiating arrangement for an electronic assembly, which includes heat generating semiconductor devices, comprises a thermally conductive holder member 20 for the semiconductor device 13 which is conveniently clamped to a large area, heat radiating member 12. The holder member 20 is adapted to be mounted, secure from rotation, to a circuit board 11 to which the semiconductor device 13 is electrically connected.