Abstract: In an optical cable made by forming a sheath on enclosing one or more optical fiber cores and a tension member, high reliability is obtained through the avoidance of adverse effects on the optical fiber core of a curving tendency of the tension member prevailing over the resistance of the sheath to curving (for example, due to the installed optical cable being heated by electrical equipment in proximity) and the optical cable consequently curving. Taking the plane containing the curve formed by the tension member due to its curving tendency as a base plane, the optical fiber core is disposed in the proximity of the position of the image formed when the tension member is projected in a direction perpendicular with respect to the base plane onto a flat plane separate from and parallel with the base plane.

Abstract: The invention is to provide an optical fiber cable in which an end of an optical fiber core is prevented from being dragged inside the main cable body part upon the application of a tension on the optical fiber cable, and which prevents the increase in transmission loss and breakage of the optical fiber core caused by the movement of the optical fiber core near the connection point. The invention can be characterized in that an optical fiber cable is formed in such a manner that yarns are stranded in a periphery of the stack of the optical fiber ribbons, and an outer sheath of the main cable body part is formed with a tension member united thereto on the periphery of the yarns.

Abstract: A cable and a cable stripping method which facilitates the stripping of an intermediate part of a cable comprising a cable core covered by a plastic sheath provided around the outer periphery without damaging the cable core. In a cable having a plastic sheath 2 on a cable core 1, either a groove 2a is provided in the inner surface of the plastic sheath 2 extending in the longitudinal direction of the cable and a ripcord 3 is fitted in the groove 2a or a ripcord 3 is adhered to the inner surface of the plastic sheath, and in either case the position-indicating means 2b showing the position of the ripcord is provided on the outer surface of the plastic sheath 2 at the point where the ripcord 3 is fitted.

Abstract: In an optical fiber cable with a jacket in which a plurality of optical fibers are assembled as being S-Z stranded about a central member, a ferromagnetic member is disposed near an inner peripheral surface of the jacket along an S-Z stranded line formed by one of the optical fibers.

Abstract: An optical fiber cable in which optical fiber ribbon stack can be accommodated in a cylindrical space efficiently and which has excellent loss characteristic. A plurality of optical fiber ribbons 1 are stacked. Cushioning fillers 2 are disposed around the optical fiber ribbon stack 1. The optical fiber ribbon stack 1 and the cushioning fillers 2 are accommodated in a cylindrical member 3. The space factor of the cushioning fillers in the inner space of the cylindrical member as a remainder after removal of the optical fiber ribbon stack from the inner space is from 10 to 60%. Consequently, the optical fiber cable becomes excellent both in initial transmission loss and in loss increasing characteristic at a low temperature.

Abstract: In the optical cable in accordance with the present invention, the reversal angle &phgr; from one reverse portion to the next reverse portion in an S-Z type helical groove is at least 180 degrees; and, letting W, T, and n be the width and thickness of each optical fiber ribbon and the number of stacked sheets of optical fiber ribbons, respectively, and a and b be the width and depth of the helical groove, respectively, at least each reverse portion of the helical groove has a cross-sectional form satisfying: nT<a≦{square root over (W2+L +(nT+L )2+L )}  (1) W<b  (2) whereas the remaining portion of the helical groove has a cross-sectional form satisfying: {square root over (W2+L +(nT+L )2+L )}<min(a, b)  (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: An optical cable has a plurality of optical fibers. The optical fibers are contained in fiber containing cavities of chamber elements. Each chamber element has a bottom part and a pair of side wall parts, which defines a fiber containing cavity. The individual chamber elements containing the optical fibers are assembled around a thickening layer in an S-Z strand. Each side wall part is formed such that its thickness gradually decreases from its base end portion toward free end portion. Also, the thickness of the bottom part is greater than the thickness of each side wall part.

Abstract: A spacer having a high-tensile member at the center thereof has grooves extending helically. Coated optical fibers have been disposed in each groove. This assembly is covered with a wound covering and further with a sheath. The proportion of the total sectional area of the coated optical fibers to the sectional area of each groove, i.e., the degree of packing, is regulated to 10 to 50%.

Abstract: An optical cable has an S-Z stranded part in which plurality of chamber elements containing optical fibers are assembled around a central member in an S-Z strand in the state where their bottom faces are in contact with the central member. Each chamber element has such a characteristic that its flexural rigidity in the depth direction of its fiber containing cavity is smaller than that in the widthwise direction thereof. Assuming, of distortion energy of the chamber element in an S-Z reverse portion within the S-Z stranded part, the distortion energy in the case where the bottom face of the chamber element is in contact with the central member to be U.sub.1, and the distortion energy in the case where a side face of the chamber element is in contact with the central member to be U.sub.2, a relational expression of .DELTA.U=U.sub.1 -U.sub.2 .ltoreq.0.2(mJ/mm) is satisfied.

Abstract: The present invention relates to a dispersion-shifted fiber having a structure which can restrain the bending loss caused by enlargement in mode field diameter from increasing. This dispersion-shifted fiber is a single-mode optical fiber mainly composed of silica glass and has a cutoff wavelength not shorter than the wavelength of signal light at its length of 2 m and a zero-dispersion wavelength within the range of 1.4 .mu.m to 1.7 .mu.m. Further, the mode field diameter in this dispersion-shifted fiber is 9.0 .mu.m or more.

Abstract: The present invention relates to a dispersion-shifted fiber having a structure for effectively lowering polarization-mode dispersion. This dispersion-shifted fiber is a single-mode optical fiber mainly composed of silica glass and has a zero-dispersion wavelength set within the range of at least 1.4 .mu.m but not longer than 1.7 .mu.m. In particular, at least the whole core region of the dispersion-shifted fiber contains fluorine.

Abstract: A rubber-modified styrene-based resin composition comprising (A) 70 to 92% by weight of a styrene-based polymer and 30 to 8% by weight of a rubbery polymer wherein the rubbery polymer is dispersed in the styrene-based polymer in the form of particles having an occlusion structure with a plane of symmetry, an area average particle diameter of 0.1 to 0.7 .mu.m, and a ratio of area average particle diameter to number average particle diameter of 1.0 to 2.5, the weight ratio of gel content to rubbery polymer is 1.1:1 to 4.0:1, and the swelling index is 5 to 20. The styrene-based resin composition has excellent physical properties and can be used as a material for office automation equipment, home electric appliances, sheets and so on.

Abstract: A styrene-based resin composition comprising (A) a styrene-based polymer and (B) a rubber-like polymer dispersed in the styrene-based polymer. The dispersed particles of the rubber-like polymer comprise a styrene-butadiene-based block copolymer comprising 5 to 95% by weight of a conventional diblock-type polymer and 95 to 5% by weight of a tapered block-type polymer, wherein the butadiene unit content of the styrene-butadiene-based block copolymer is 6 to 16% by weight, based on the weight of the composition. The particles have a weight ratio of gel content to rubber-like polymer of 1.1:1 to 4.0:1 and have a swelling index of 5 to 20. The particles have an area average diameter of 0.1 to 0.9 .mu.m, with a ratio of area particle diameter to number average particle diameter of 1.0 to 1.8. The styrene-based resin composition has a high Izod impact strength and a high drop-weight impact strength, and further has excellent gloss and stiffness properties.