Abstract: Tensile strength of a tape layer in the lengthwise direction is selected to be higher than adhesive force of the tape layer to optical fiber cores. Further, position limiting portions 111 by which the positions of a plurality of optical fibers 120 can be limited are formed in a flexible film 110 for tape core assembly which film is used for integrating the plurality of optical fibers 120 as a tape. Further, a ribbon-like optical fiber core assembly 301 according to the invention including a plurality of optical fiber cores 302 arranged planarly at designated intervals, an adhesive layer 305 disposed so as to surround the optical fiber cores 302, and films 304a and 304b integrated with the optical fiber cores 302 by the adhesive layer 305.

Abstract: A positioning of a plurality of optical fibers 11 is performed by a pair of position regulating members 12a and 12b. Then, the paired position regulating members 12a and 12b are moved along two guide members 13, 13 in such a manner as to have a predetermined distance therebetween. A ribbon support member 15 is placed between the paired position regulating members 12a and 12b in such a way as to support the optical fibers 11. The plurality of optical fibers 11 are held and fixed by the holding members 17a and 17b. Further, the plurality of optical fibers 11 put on the ribbon support member 15 are sandwiched by the ribbon support member 15 and the pressing tool 19 opposed thereto. In a terminal portion structure 110a of a ribbon fiber 10, terminal portions of optical fibers 102 are arranged horizontally in parallel, an adhesive tape is stuck onto at least one of upper and lower surfaces of at least the terminal portions.

Abstract: An optical fiber ribbon comprising a plurality of the coated optical fibers 2 arranged in plane and flame-retardant films 4a and 4b to integrate the coated optical fibers 2 is provided. The flame-retardant films 4a and 4b have an adhesive layer 5 formed thereon, and a plurality of the coated optical fibers 2 arranged in plane are integrated by the adhesive layer. The optical fiber ribbon 1 in this constitution uses flame-retardant films, wherein the ribbon thickness can be lowered and separation of single fiber can be facilitated by tearing off the film.

Abstract: A jack used in an action mechanism of a piano has substantially an L-shape, composed of a big jack portion and a small jack portion. The thickness of the small jack portion is made smaller than that of the big jack portion in a direction of key arrangement in a state of the jack being fitted in the piano. By reducing the weight of the small jack portion as above, the time required for the jack to return to a position capable of pushing up a part of a striking member can be shortened. Accordingly, more frequent repetitive striking is allowed within a predetermined period.

Abstract: A rigid polyurethane foam obtained by foaming a special polyol component and an isocyanate component in the presence of a blowing agent comprising water and at least one member selected from the group consisting of 1,1-dichloro-2,2,2-trifluoroethane and 2,2-dichloro-2-monofluoroethane possesses balanced excellent properties, has no surface void, and shows only slight expansion after molding. Therefore, it can be effectively used as a heat insulator, in particular, a heat insulator for refrigerators.