Abstract: To provide a strip connecting apparatus and a method therefor which are less costly, short in welding time and high in welding quality. A strip connecting apparatus is provided with: a surface coating removing device for removing insulative surface coating of end portions, to be welded, of a leading strip and a trailing strip before cutting the strips; a cutting device for cutting the end portions, to be welded, of the leading strip and the trailing strip; and a welding device for overlapping the cut end portions of the leading strip and the trailing strip and seam welding the cut end portions with each other.

Abstract: Two position detectors for a leading strip and two position detectors for the trailing strip are provided so as to be separated each other by a certain distance along each of the strips in a transferring direction of the strips to detect a deviation of a center line of each of the strips in a width direction of the strips with respect to a center line of a processing line. Two alignment devices for the leading strip and two alignment devices for the trailing strip, which are provided so as to be separated by a certain distance in the transferring direction, clamp each of the strips and adjust a position of each of the strips in the width direction in response to each of the detected deviations to align the center line of each of the strips with the center line of the processing line.

Abstract: A plurality of pistons are disposed in series in a circular electrode pressure cylinder and each of the pistons is separated. During low pressure output only one piston is used so that the friction force of the other pistons is not transmitted.

Abstract: An object of the present invention is to provide plate width center alignment method and apparatus for a welding machine, which can dispense with a detection driving device, which is simple in construction but can perform the detection from a position closest to a cutting-welding position, and which is high in plate width center alignment accuracy. Plate side edge detectors which are included in a plate width center alignment means for detecting plate widths of two cut plates and aligning plate width centers with each other, and which detect widthwise plate side edges of the two cut plates, are disposed on a movable frame provided with a cutting means and a welding means, elongated in the width direction of a web and movable in that direction.

Abstract: A welding apparatus comprises a pair of clamping devices for clamping the workpieces to prevent slip under applying significantly large force to the butting surfaces for the butt welding operation and a pair of electrode tables for feeding a welding current. The welding apparatus need not comprise a step gauge bar nor an auxiliary clamp in order to set the projecting degree.