Abstract: A submarine power feeding branching device comprises a constant current-constant current converter which isolates an input side for a trunk submarine cable from an output side for a branch submarine cable. The converter receives a first constant current and produces a second constant current by using the first constant current. The second constant current is supplied to the output side while the first constant current is returned to the input side. Because the input side and the output side are isolated, it is easy to add/remove the device to/from a submarine power feeding system. Intensity of the second constant current can be controlled by controlling duty ratios of switches included in the converter. Thus, it is possible that the intensity of the second constant current is equal to that of the first constant current. Therefore, a submarine repeater can be provided along either the trunk cable or the branch cable.

Abstract: A submarine cable power feeding system includes N (N is an integer of 2 or larger) main submarine cables extending from the land in the offshore direction, N-stage (N is an integer of 2 or larger) submarine feed branching devices, and first to Nth (N is an integer of 2 or larger) sub submarine cables. Each submarine feed branching device is connected to the main submarine cable to receive constant-voltage power from a constant-voltage feed unit. Each sub submarine cable connects the Nth-stage submarine feed branching device, connected to the Nth main submarine cable, to the adjacent submarine feed branching device through submarine repeaters, thereby receiving power from a constant-current feed unit. Each constant-current feed unit is built in the submarine feed branching device. The submarine feed branching devices and the submarine repeaters are arranged in a matrix on a plane.

Abstract: A feed line switching circuit includes a relay connected between feed lines, a normally close contact of the relay, and a resistor that constitutes a series circuit with the normally close contact, which series circuit is connected in parallel with the relay. The resistance of the coil of the relay and the resistance of the resistor are determined to satisfy the condition that the current flowing through the relay after energizing the relay can prevent the chattering of the relay. Thus, the feed line switching circuit can positively carry out the feed line switching.

Abstract: A feed line switching circuit includes a relay connected between feed lines, a normally close contact of the relay, and a resistor that constitutes a series circuit with the normally close contact, which series circuit is connected in parallel with the relay. The resistance of the coil of the relay and the resistance of the resistor are determined to satisfy the condition that the current flowing through the relay after energizing the relay can prevent the chattering of the relay. Thus, the feed line switching circuit can positively carry out the feed line switching.

Abstract: A feed line connecting circuit for selectively connecting first, second and third feed line connecting terminals under a predetermined current feeding condition comprises a first current detector connected between one of the first and second feed line connecting terminals and a central node for detecting a current over a predetermined value; a first switch connected between the one of the first and second feed line connecting terminals and the central node for connecting said one of the first and second feed line connecting terminals to the central node under an unpowered condition; a selective switch controlled by the first current detector, the selective switch having first and second contacts and a common contact connected to the third feed line connecting terminal, the common contact being connected to the first selective contact when the first current detector does not detect a current over the predetermined value, and to the second selective contact when the first current detector detects a current over

Abstract: When a trouble occurs in a cable, a feeding pass for another cable is ensured. In a feeding pass switching circuit, optical fibers are respectively connected to the terminals A, B and C. When a negative current is applied to the system in a state where a BRANCH2 is put in an open circuit and a TRUNK is grounded, a relay K1 is activated, and then a relay K2 is activated. Successively, when a positive current is supplied from the TRUNK, a cable connected to the TRUNK and a BRANCH1 is fed from both terminals. When the positive current is supplied from the BRANCH1 in a state where the TRUNK is put in a open circuit and the BRANCH2 is grounded, a relay K3 is activated. Successively, when the negative current is supplied to the BRANCH2, a relay K5 is activated. In such a manner, the power is fed to each feeding pass from one terminal.

Abstract: A remotely operated submersible robot 10 is provided with two differential triaxial orthogonal dc magnetic sensing units, 1 and 2, each comprising two triaxial orthogonal dc magnetic sensors spaced at a predetermined distance apart and with their corresponding axes set in parallel; each triaxial orthogonal dc magnetic sensor incorporating three dc magnetic sensing elements sensitive only to a magnetic field in a specific axial direction and disposed such that the axial directions of respective dc magnetic sensing elements cross each other at right angles. Analog signals sent out from the differential triaxial orthogonal dc magnetic sensing units 1 and 2 are converted into digital signals by an analog-to-digital converter, and transmitted to a mother ship 20 via a tether cable 6.

Abstract: A stainless steel exhibiting excellent anticorrosion property for use in engine exhaust systems comprises not more than 0.010% C, not more than 0.2% Si, 0.05%-1.5% Mn, 12%-20% Cr, 0.2%-3.0% Mo, 0.005%-0.1% Al, not more than 0.015% N, not more than 0.025% P, not more than 0.010% S, either or both of 10.times.(C %+N %)-0.5% Ti and 5.times.(C %+N %) 0.5% Nb, and the balance of Fe and unavoidable impurities. An additional improvement in the anticorrosion property of the stainless steel can be obtained by further adding thereto one or more of 0.1%-1.0% Ni, 0.03%-1.0% Cu, 0.05%-0.5% W, 0.05%-0.5% V and 0.05%-1.0% Zr and/or one or both of 0.001%-0.03% Ca and 0.001%-0.03% Ce.

Abstract: Disclosed is a coated steel sheet valuable for the production of a fuel vessel, in which a first covering layer comprising a Pb-Sn alloy as the main component is formed on a substrate comprising a steel sheet and an undercoat covering layer composed of at least one member selected from Ni, Co and Cu, which is formed on the surface of the steel sheet according to need, a second covering layer containing a compound containing Pb and P is formed on the first covering layer, a third covering layer containing at least one member selected from Sn, Ni and Co is formed on the second covering layer, and according to need, the surface portion of the third covering layer is modified with a treating liquid containing a phosphoric acid ion or a chromic acid ion. This coated steel sheet shows a highly improved corrosion resistance, forming processability, solderability, and weldability.

Abstract: A core alignment system for aligning a pair of optical fibers to be spliced, in which core alignment is accomplished by applying a pair of aligned beams of light emitted in opposite directions by a semiconductor laser to the butt joint ends of a pair of optical fibers to be spliced, detecting a leakage beam leaking from a side surface of each optical fiber close to the laser, and adjusting the positioning of the optical fibers so that the leakage beams are minimized.

Abstract: A hot-dip aluminium coated steel sheet having excellent corrosion resistance and heat resistance, comprising a steel substrate containing 3 to 18% chromium, not more than 0.02% carbon, 0.1 to 1.5% manganese, 0.005 to 0.08% aluminium, not more than 0.1% silicon, with the balance being iron and unavoidable impurities, and aluminium coating on said sheet substrate. The coated sheet may further comprises a coating layer of nickel or nickel-iron alloy (Ni: 1 to 99%) beneath the aluminium coating, or an Al-Fe-Si-Ni-Cr alloy coating layer of 1 to 10.mu. in thickness and containing 0.05 to 5% nickel, 0.2 to 10% chromium, beneath the aluminium coating.

Abstract: A chromate treatment of metal coated steel sheets comprising subjecting the sheets to a cathodic electrolytic treatment to form a chromate film thereon and subjecting the sheet to an anodic electrolytic treatment to form an anodic electrolytic film on the chromate film and to convert the chromate film. The treatment is applicable to various metal coated steel sheets, such as those coated with zinc, zinc alloy, aluminum, aluminum alloy, lead and lead alloy, and is effective to improve the corrosion resistance of the sheets, the quality of paint coating applied on the sheets and the adaptability of the sheets to a cation electro-deposition paint coating.

Abstract: Coated steel sheet of high corrosion resistance comprises a sheet of steel containing not more than 0.1% by weight of carbon, 0.005 to 0.08% by weight of soluble aluminum and 0.2 to 20% by weight of chromium, the balance being iron and unavoidable impurities. The steel carries a nickel or nickel alloy layer formed on at least one surface thereof and having a thickness of 0.001 to 1.5 microns and a layer of tin formed on the nickel or nickel alloy layer and having a thickness of at least 0.05 micron. A method of producing it is also disclosed.

Abstract: A device for burying a submarine cable under water by easily and accurately detecting the cable position and a method for guiding the same by utilizing the characteristics unique to submarine cables, by supplying an AC only to the portion of the cable between two arbitrary repeaters through a so-called transformer-coupling system to generate an AC magnetic field, and by detecting the magnetic field with a magnetic field detector.

Abstract: A rotary joint for optical fibers consists of two rotary members which enable efficient transmission of optical signals without the need of converting the same into electric signals by attaching rod lenses having a refractive index in the second order distribution relative to its center axis, to respective tips of the optical fibers capable of relative rotation so that an optical signal emitted from the tip of one optical fiber is transmitted from the end of one rod lens in the form of parallel rays to the other rod lens, and as a converged beam to the tip of the other optical fiber. The joint further includes a mechanism for imparting pressure to the rotary members, and a mechanism for finely setting the angle between the two rod lenses.

Abstract: This invention aims to provide an optical fiber which is capable of sufficiently dissipating the leaky mode in the cladding thereof characterizing in those particulate substances such as minute hollow glass beads having different refractive indices are sealed in the primary buffer layer or on the boundary between the primary buffer layer and the cladding, or between the primary and secondary buffer layers of the optical fiber, whereby nucleous elements for scattering or absorption can be formed uniformly.

Abstract: A device for burying a submarine cable under water by easily and accurately directing the cable position and a method for guiding the same by utilizing the characteristics unique to submarine cables, by supplying an AC only to the portion of the cable between two arbitrary repeaters through a so-called transformer-coupling system to generate an AC magnetic field, and by detecting the magnetic field with a magnetic field detector.

Abstract: A continuous hot dip aluminum coating method used in a continuous hot dip aluminum coating line for hot dip aluminum coating on steel in Sendzimir method or nonoxidizing furnace method, said method comprising the covering the surface of the coating bath in the snout of said hot dip coating line by use of an inert gas atmosphere.

Abstract: A connector for connecting together in a water-tight housing various optical instruments of an underwater or submarine arrangement having optical fiber cables. The connector is constructed in a manner such that a plug containing the terminals of optical fiber cables is connected in an easily attachable/detachable fashion to a receptacle which is mounted on the water-tight housing. Sealing material is interposed between the water-tight housing and the receptacle and between the receptacle and the plug for preventing the infiltration of water or sea water into the water-tight housing.

Abstract: A device for burying a submarine cable under the water by easily and accurately detecting the cable position and a method for guiding the same by utilizing the characteristics unique to submarine cables, by supplying an AC only to the portion of the cable between two arbitrary repeaters through a so-called transformer-coupling system to generate an AC magnetic field, and by detecting the magnetic field with a magnetic field detector.