Abstract: A laser welding device for welding a long sized tubular grounding unit includes a work head arranged to rotate around an outer circumference of two tubular members to be welded, a laser oscillator, and apparatus to transmit the laser beam from the oscillator in sychronism with rotation of the work head. In one embodiment the apparatus to transmit the laser beam includes an optical fiber.

Abstract: A welded metal container for a sheath 1 or 1A of gas insulated switch gear comprises a trunk pipe 2, 21 and a branch pipes 3, 31, 32 welded to the trunk pipe 2,21 by arc welding A or laser beam welding LB and flanges welded to the each end portion of the trunk pipe 2, 21 and branch pipes 3, 31, 32 by the laser beam welding. After the arc welding A, the ends of trunk pipe 1, 21 and branch pipes 3, 31, 32 are machined precisely and flanges 4a, 4b, 4c, 4d, 4f and 4g are welded to the end portions of the trunk pipe 2, 21 and branch pipes 3, 31, 32.

Abstract: A method for manufacturing a welded metal container by first arc welding a branch pipe to a trunk pipe. The arc welding of the pipes together causes both of the pipes to be thermally deformed. The end surfaces of the pipes are then cut by a laser cutting or mechanical cutting process so that the ends of the trunk pipe are in parallel and perpendicular to the end of the branch pipe. Subsequently flanges are laser welded to the ends of the pipes without further thermally deforming the pipes. The metal container made by this process can be used as a sheath for a gas insulated switch gear.

Abstract: An apparatus for connecting wiring patterns on a wiring board and leads of a parts to be mounted on the wiring board, via the solder provided between the leads and the patterns. The parts-connecting apparatus enables, especially, circuit elements of a high degree of, to be connected automatically with high reliability and accuracy by using solder through the steps of setting the wiring board in a predetermined position while pressing a surface thereof so as to remove the warp from the wiring board, fastening the leads of the part to the wiring patterns by a magnet provided on the lower surface of the wiring board, and heating the solder provided on the portions of the leads which are fastened to the wiring patterns.

Abstract: In an apparatus for punching the tuyeres of a converter for smelting of copper or nickel, the apparatus including a carrier frame supported by wheels and which is capable of moving on the working platform located adjacent to the converter, the carrier frame mounting a plurality of punch rods which can reciprocatingly extend into respective tuyeres to remove deposits therein. An electric motor is employed to drive the carrier frame and an electrical control system controls the operation of the electric motor and thus the movement of the carrier frame so that the correct positioning of the punch rods with respect to the tuyeres on a converter can be automatically achieved.