Abstract: A method is provided for adjusting the thickness of the welding bead of two bands obtained by butt welding by means of a laser beam without using filler material. The bands are clamped in jaws, both cut edges being spaced apart by a reference distance. Then the mobile jaw is moved along a travel. Said travel differs from said reference distance by an offset calculated in relation to the thickness of the bands, and while taking into account the degree of accuracy of the positioning and of the cut of said edges. The offset is counted as positive or negative, in order to obtain a final welding position such that it exists, between the edges, an actual allowance, positive or negative, adapted to the thickness of the bands.

Abstract: The invention concerns a method for adjusting the thickness of the welding bead of two bands (M1, M2) obtained by butt welding by means of a laser beam without using filler material. The bands are clamped in jaws (S1, S2), both cut edges (10, 20) being spaced apart by a reference distance (D?). Then the mobile jaw is moved along a travel (C). Said travel (C) differs from said reference distance (D?) by a preset play calculated in relation to the thickness of the bands, and while taking into account the degree of accuracy of the positioning and of the cut of said edges (10, 20). The preset play is counted as positive or negative, in order to obtain a final welding position such that it exists, between the edges (10, 20), an actual allowance, positive or negative, adapted to the thickness of the bends.

Abstract: The invention concerns a method for controlling the butt welding, by flash welding, of two metallic parts (A, A?) in a welding machine of the type comprising two pairs of clamping dies (2, 2?) mounted respectively on a fixed frame (1) and on a mobile frame (1?) for contacting rear (3) and front (3?) ends of both parts (A, A?) and the flow of an electric welding current. According to the invention, on the one hand a set of electric parameters including at least the voltage (Us) and the intensity (Is) of the welding current and on the other hand the relative position of the mobile frame (1?) with respect to the fixed frame (1) are measured at any moment and the travel of the mobile frame (1?) is regulated in position from at least one of the measured value of said electric parameters, in order to control the closing-in speed v(t) of the ends (3, 3?) of both parts (A, A?) taking in account the progress of the welding process, during at least a portion thereof.

Abstract: The invention concerns a method for controlling the butt welding, by flash welding, of two metallic parts (A, A′) in a welding machine of the type comprising two pairs of clamping dies (2, 2′) mounted respectively on a fixed frame (1) and on a mobile frame (1′) for contacting rear (3) and front (3′) ends of both parts (A, A′) and the flow of an electric welding current.

Abstract: The invention relates to an installation for welding metal bands comprising two retaining members (2, 2′) for the ends of both bands, mounted respectively on a fixed frame (1) and a mobile frame (1′), means for shearing both facing parallel edges (m1, m2) on the ends of both bands (M1, M2) and electric power supply means (3) for flash butt welding of the said bands. According to the invention, the electric power supply means of both bands comprise a direct current generator (3) connected to continuous modulation means (34) of the voltage applied between the retaining members (2, 2′) in relation to the sizes of the bands (M1, M2) in transversal section and according to the nature of the metals to be welded.

Abstract: The subject of the present invention is a method of spot resistance welding at least two metal pieces (1, 2). The method consists in pressing the pieces (1, 2) between two electrodes (3, 4), in determining the overall resistance between the electrodes (3, 4), and the contact resistances of each electrode (3, 4) with the piece (1, 2) with which it is in contact, in calculating the contact resistance between the said pieces by the difference between the overall resistance and the sum of the resistances of each piece and of the piece-electrode contact resistances, in determining the actual intensity of the electric welding current, and in adjusting the various welding parameters for the said pieces (1, 2) in order to maintain a constant optimal intensity of the electric welding current.The subject of the present invention is also a welding electrode for implementing the method.