Abstract: Four twisted pairs 115 are forced to be brought into contact with a hollow filler 113 and collectively arranged around the hollow filler 113 so as to deform a contact portion into a concave form. The outer periphery of the four twisted pairs 115 collectively arranged is covered with a jacket 117 to form a data transmission cable 111.

Abstract: An optical fiber ribbon cord 10 comprising a plurality of tension fibers 13 juxtaposed along about an optical fiber ribbon 11 and a sheath 14 composed of a resin covering all the exteriors thereof, wherein at least one tape body 15 with higher Young's modulus than that of the sheath is inserted within the interior A of a side wall in the minor axis of the sheath.

Abstract: The manufacturing apparatus for optical fiber cord is provided with an extrusion machine, a cooling chamber, an intermediate pulling device, a heating chamber, a final pulling device, and a winding machine wherein the machines, the devices and the chambers are disposed in this order. One or more optical fiber cores and one or more reinforcing fibers are sheathed with thermoplastic resin by the extrusion machine. The thermoplastic resin is solidified by cooling so as to be a resin sheath. The sheathed fibers are annealed by the heating chamber so that its residual stress is relieved.

Abstract: An optical fiber unit for air blown fiber installation, including an optical fiber wire; an inner coating layer formed on an outer periphery of the optical fiber wire with a modulus of elasticity ranging from 0.98 to 196 MPa; an outer coating layer formed on an outer periphery of the inner coating layer with a modulus of elasticity ranging from 196 to 1960 MPa; and a foamed plastic layer formed on an outer periphery of the outer coating layer.

Abstract: A resin liquid is provided which is used to produce an optical fiber coating layer which does not degrade over time in long-period transmission characteristics of the optical fiber. An optical fiber in which long-period transmission characteristics do not degrade is also provided. In order to achieve these objects, the present invention provides a resin liquid for an optical fiber coating layer containing at least one resin, wherein the resin liquid contains fewer than 500 pieces of extraneous material per 1 ml of the resin liquid, which have a minimum length of 0.5 ,&mgr;m or more and a hardness greater than a hardness of the resin liquid after curing.

Abstract: An optical fiber drop cable 1 is disclosed including an elongated optical element section 7 composed of an optical fiber core wire 5 and at least one pair of adjacent first tensile strength members 13, disposed on both sides of the optical fiber core wire 5 in parallel thereto, which are covered with a cable sheath 3, and an elongated cable support wire section 11 having a second tensile strength member 17 covered with a sheath 19 and adhered to the optical element section 7 in parallel thereto. Since an outer periphery of the first tensile strength member 13 is formed in a rugged configuration, an increased adhesive force is provided between the first tensile strength member 13 and the cable sheath 3 due to an anchoring effect of the rugged configuration.

Abstract: This dispersion compensating optical fiber comprises an uncovered dispersion compensating optical fiber which contains a core and a cladding and a resin coating which is disposed around the uncovered dispersion compensating optical fiber and which has an adhesive property of 10 g/mm or less. Alternatively, the dispersion compensating optical fiber comprises an uncovered dispersion compensating optical fiber which contains a core and a cladding and a resin coating which is disposed around the uncovered dispersion compensating optical fiber, which has an adhesive property of 1 g/mm or less, and which includes a single or double coating layer and an outer coating layer formed on the surface of the single or double coating layer to have a thickness of 3 &mgr;m or more.

Abstract: Provided is an optical fiber drop cable, which protects an accident by lightning strike having also a low cost, and a manufacturing method thereof.

Abstract: An optical fiber ribbon and an optical fiber cable are described in which light loss during winding an optical fiber ribbon on a bobbin and during installation of optical fiber ribbons in an optical fiber cable is prevented by giving slip characteristics to the surface of the optical fiber ribbon to avoid increase of light loss. The optical fiber ribbon comprises a plurality of individual optical fibers and a ribbon material covering said individual optical fibers in the form of a ribbon. The ribbon material is made of a UV curable resin having a monomer structure or an oligomer structure and provided with a slip characteristic. The optical fiber cable is composed of a plurality of the optical fiber ribbons.

Abstract: A single optical fiber tight cord having durable surface which is not cracked even under bending stress is described. The single optical fiber tight cord comprises a optical fiber; a plurality of glass fibers which are located around said optical fiber in parallel with said optical fiber; a UV curable resin provided around said optical fiber together with said glass fibers for fixing said glass fibers around said optical fiber; a UV curable resin layer covering and fixed around said optical fiber; and an outermost layer covering and fixed around said UV curable resin layer and made of a resin which is more excellent than said UV curable resin layer in tractility.

Abstract: An optical fiber drop cable including an optical element portion 3 having an optical fiber core wire 1 and a pair of first tension members A disposed parallel to the optical fiber core wire 1 on both sides thereof in a sandwiching manner, the optical fiber core wire 1 and the pair of first tension members A being coated with a cable sheath 21, and a long-scale cable support wire portion 4 having another second tension member B coated with a sheath 22, the optical element portion 3 and the cable support wire portion 4 being adhered parallel to each other, wherein the first tension members A are composed of a nonconductive material. A flexural rigidity of the optical element portion 3 is in a range from 80 to 500 Nmm2.

Abstract: The present invention provides a simple method for fixing a protective tube covering an optical fiber extending from an end of an optical fiber sheet to the optical fiber sheet. The method comprises the steps of: abutting the protective tube against the end of the optical fiber sheet; setting metallic molds so as to surround the abutted portion of the protective tube and the end of the optical fiber sheet; and injecting a hot-melt resin into the metallic molds so as to cover the abutted portion with the hot-melt resin. According to this simple method, the protective tube can be fixed to the optical fiber sheet with a sufficient strength.

Abstract: A thermoplastic resin coated optical fiber having an outer diameter of 0.9 mm is formed by providing a coating layer around a reinforcing resin coated optical fiber having an outer diameter of 0.25 mm, and has a flexural rigidity of 5.5 to 7.5 N·mm2. The coating layer comprises a thermoplastic resin having a bending elastic modulus of 200 to 350 MPa and the thermoplastic resin is a polyester elastomer. When optical fiber cords are connected to each other or when an optical fiber is exposed to low temperatures, loss is prevented from increasing and superior transmission characteristics are exhibited.

Abstract: A binder is used for binding foundry sand to form a mold and a core for casting, and consists of a condensation-reactive first compound (resin) having at least one methylol group in a molecule, amounting to 100 parts by weight. An additive component is added to the resin to improve the strength and the sand removability of the mold and the core while improving the production yield of the mold and the core. The additive component includes at least one of calcium hydroxide and barium hydroxide in particle form. The particle surface of the at least one of calcium hydroxide and barium hydroxide is coated with a second compound having a melting point not lower than 50.degree. C. and a boiling point ranging from 250.degree. to 400.degree. C., the second compound ranging from 0.5 to 35 parts by weight.