Abstract: An optical connector includes a cylindrical front body formed with a center bore having a front cylindrical bore, a rear cylindrical bore and a tapered bore therebetween. A fiber holding unit made of a flexible material is separable into two parts, whose mating surfaces are formed with grooves for holding an optical fiber and at front and rear portions with spacers for partially preventing contact between the mating surfaces in the proximity of the spacers. The two assembled parts form cylindrical outer surfaces at front and rear ends and a tapered outer surface between the cylindrical outer surfaces. The two assembled parts with the optical fiber interposed therebetween are able to be fitted in the front body from its rear end.

Abstract: An improved magnus measuring apparatus for providing an automatic initial setting at high speed in testing a plurality of biological specimens which moves elastically with beats, wherein a tensile force is applied on a specimen by moving the transducer connected thereto with use of a motor to be driven and stopped under the control of a control unit, and thereby the rotating speed of the motor is increased gradually at least for a predetermined period of time from the start and then kept at high speed for bringing a bottom value of the tensile force to enter an extent of preliminarily set initial value.

Abstract: In a process for producing carbon fibers from a carbonaceous pitch, the improvement characterized in that an end portion of infusiblized fiber or carbonized fiber to be first subjected to a carbonizing or graphitizing treatment and that of infusiblized fiber or carbonized fiber to be next subjected to the same treatment are bonded together using a composition comprising (a) at least one member selected from the group consisting of phenolic resins and pitches and (b) graphite powder, and the thus-bonded fibers are fed successively to a carbonizing apparatus or a graphitizing apparatus.

Abstract: A fiber sensor for measuring temperature or strain comprises a first polarization-maintaining fiber and a second polarization-maintaining fiber. In case of a temperature fiber sensor, the first and second fibers are selected to be unequal in change in phase difference caused by change in temperature but equal in change in phase difference caused by strain. In case of a strain fiber sensor, the first and second fibers are selected to be unequal in change in phase difference caused by strain but equal in change in phase difference caused by change in temperature. Axes of polarization of the first and second fibers are shifted by 90.degree. at a junction of the fibers. With this arrangement, the temperature fiber sensor can measure the change in temperature with high accuracy without being affected by strain, while the strain fiber sensor can measure the strain with high accuracy without being affected by the change in temperature.

Abstract: A ferrule holding device is used for holding a ferrule accommodating optical fibers therein. Two ferrules are inserted in a sleeve extending in two connector bodies of the connector to bring the optical fibers to be in aligned and close contact with each other by spring means urging the ferrules toward each other. According to the invention, the device comprises a spring urged sleeve consisting of a cylindrical body having an outer diameter somewhat smaller than an inner diameter of each the connector body. The cylindrical body is provided at plural locations with resilient curved pieces having hooks outwardly extending but depressible inwardly of an outer periphery of the cylindrical body. The connector body is formed with anchoring apertures into which the hooks of the resilient curved pieces extend so as to hold the spring urged sleeve in the connector to support the spring means urging the ferrule.

Abstract: In the process for producing pitch carbon fibers by melt-spinning a carbonaceous pitch, and infusiblizing the resulting pitch fibers followed by carbonization and, additionally as needed, graphitization, the pitch fibers are subjected to infusiblization treatment following application of a dimethyl polysiloxane having a viscosity at 25.degree. C. in the range between 0.5 and 500 cSt and removing said dimethyl polysiloxane by washing prior to the carbonization.

Abstract: Provided is a process for producing pitch carbon fibers by subjecting pitch fibers obtained by melt-spinning a carbonaceous pitch to infusibilization treatment and then to carbonization treatment or both carbonization treatment and subsequent graphitization treatment, characterized in that a dimethyl polysiloxane having a viscosity at 25.degree. C. in the range of 12,000 to 1,000,000 cSt is applied to the fibers after the infusibilization treatment, and the infusibilized fibers with the dimethyl polysiloxane thus applied thereto are then subjected to the carbonization treatment or both the carbonization treatment and the subsequent graphitization treatment.

Abstract: A precursor pitch for the production of carton fibers is obtained by heat-treating a carbonaceous pitch in the form of a thin film having a thickness not larger than 5 mm at a temperature in the range of 250.degree. to 390.degree. C. and under a reduced pressure not higher than 100 mmHg. By melt-spinning this precursor pitch and subjecting the resultant pitch fiber to infusiblization and carbonization and, if required, to subsequent graphitization, there is obtained a high quality carbon fiber.

Abstract: Provided is a process for producing a pitch-based graphite fiber, which process comprises treating a pitch fiber in an oxidative gas atmosphere to render it infusible, said pitch fiber being obtained by melt-spinning a carbonaceous pitch, then heat-treating the infusibilized fiber at 400.degree.-750.degree. C. in an inert gas atmosphere to obtain a precarbonized fiber substantially containing oxygen, then raising the temperature to 2,000.degree.-3,000.degree. C. at a rate of 500.degree. C. or higher per minute in an inert gas atmosphere and heat-treating the precarbonized fiber at the raised temperature of 2,000.degree.-3,000.degree. C. in said inert gas atmosphere.

Abstract: A shielded electrical connector in which the shield cover is formed as two U-shaped parts, each of which includes an integral clamping portion for clamping with a shielded connector. The clamping portions are connected to the cover parts by leg portions. An insulator containing electrical contacts is sandwiched between the cover parts after the cable is attached to the contacts. The cover parts are compressed together, following which the clamp portions are clamped about the cable to provide electrical connection between the cable and the shield cover.

Abstract: An electrical connector in which the male portion (1) is provided with a shield metal spring (8) to make an electrical connection to a metal shell (2) and its connecting section (8a) bridges over to the insulation housing (1a). The female portion (4) is provided with a metal shell (9) having a metal side section (9b) for contact with the shield metal spring (8) and the metal connecting section (8a) that is connected to a metal panel (5). When the parts are mated, the male portion metal shell (2) is automatically electrically connected to the metal panel (5).

Abstract: A process for producing carbon fibers, comprising melt spinning a carbonaceous pitch to obtain pitch fibers, contacting the thus obtained pitch fibers with hydrobromic acid, making the thus contacted fibers infusible in an oxidizing atmosphere and then carbonizing and, if desirable, graphitizing the thus treated pitch fibers to obtain the carbon fibers.

Abstract: A starting pitch for carbon fibers is obtained by mixing (1) 100 parts by volume of a heavy fraction oil boiling at not lower than 200.degree. C. and obtained at the time of fluidized catalytic cracking of petroleum with (2) 10 to 200 parts by volume of a fraction boiling in the range of 250.degree. to 550.degree. C. obtained by distilling under reduced pressure an oil produced at the time of heat treating a starting pitch and then heat treating the resulting mixture at a temperature of from 370.degree. C. to 480.degree. C. under a pressure of from 2 to 50 Kg/cm.sup.2.G thereby to obtain the starting pitch for carbon fibers. The thus obtained starting pitch is heat treated to obtain a precursor pitch which is melt spun, infusibilized, carbonized or graphitized to obtain the carbon fibers.

Abstract: A starting pitch for carbon fibers, obtained by (A) mixing together (1) a heavy fraction oil boiling at not lower than 200.degree. C. obtained at the time of fluidized catalytic cracking of petroleum, (2) a hydrogenated oil selected from aromatic hydrocarbons of 2-10 rings having their nuclei partly hydrogenated and specific fractions boiling at 160.degree.-650.degree. C. and containing such aromatic hydrocarbons and (3) a heavy fraction oil boiling at not lower than 200.degree. C. obtained at the time of steam cracking of petroleum, to form a mixture of the oils (1), (2) and (3), and then (B) heat treating the thus formed oil mixture at 370.degree.-480.degree. C. and 2-50 Kg/cm.sup.2.G thereby to obtain the starting pitch.

Abstract: A pitch which affords a carbon fiber having a high strength and a high elastic modulus is obtained by treating a pitch containing 5 to 35 weight percent of an optically anisotropic region with sulfur.

Abstract: A pitch which affords a carbon fiber having a high strength and a high elastic modulus is obtained by treating a pitch containing 5 to 35 wt. % of an optically anisotropic region with an oxidizing gas, followed by hydrogenation treatment if required.

Abstract: A process for the production of carbon fibers which comprises using a specific optically isotropic pitch having a reflectivity of 9.0-11.0% as the material for the carbon fibers.

Abstract: A process for the production of high performance carbon fibers which comprises using as the starting material a specific pitch having the lowest reflectivity in the range of 8.5-9.3% and the highest reflectivity in the range of 11.8-12.5%.

Abstract: A process for the production of carbon fibers comprising heat treating a starting material, melt spinning the resulting precursor pitch, infusibilizing the pitch fibers and carbonizing or graphitizing the infusibilized pitch fibers, characterized in that the starting pitch is obtained by heat treating coal tar and/or coal liquefaction pitch at a specific temperature and a specific hydrogen pressure or by mixing coal tar and/or coal liquefaction tar with at least one nucleus-hydrogenated hydrocarbon of 2-3 rings in a specific mixing ratio and then heat treating the resulting mixture at a specific temperature and a specific pressure. In one embodiment, this invention relates to the starting pitch and carbon fibers obtained by said process.

Abstract: A starting pitch for carbon fibers, obtained by mixing (1) a heavy fraction oil boiling at not lower than 200.degree. C. obtained at the time of steam cracking of petroleum with (2) wax and then heat treating the resulting mixture at a specified temperature and pressure thereby to obtain the starting pitch, the thus obtained starting pitch being heat treated to produce a precursor pitch which is melt spun, infusibilized, carbonized or graphitized to obtain the carbon fibers.