Abstract: An electric arc welding robot for welding a zone of a rail or the like comprises a movable, electric arc torch unit for operating the welding, first controlling means for controlling a first displacement of the torch unit substantially in front of the periphery of the zone to be welded, so that welding geometrical locations are read on said zone, by means of reading means connected to a memory unit, for memorizing said welding geometrical locations read on the rail, and second controlling means for automatically controlling a second displacement of the torch unit in front of the zone to be welded, within the limits of said reading and as a function of the welding geometrical locations, as memorized.

Abstract: An electric arc welding robot for welding a zone of a rail or the like comprises a movable, electric arc torch unit for operating the welding, first controlling means for controlling a first displacement of the torch unit substantially in front of the periphery of the zone to be welded, so that welding geometrical locations are read on said zone, by means of reading means connected to a memory unit, for memorizing said welding geometrical locations read on the rail, and second controlling means for automatically controlling a second displacement of the torch unit in front of the zone to be welded, within the limits of said reading and as a function of the welding geometrical locations, as memorized.

Abstract: An electro-welding device for electrically welding plastic elements together, comprising: a power source for having an AC current in circulation, an electrical converter AC/DC, heating means electrically connected to the converter for heating the weldable elements, electrical regulating means interposed between the electrical converter and the heating means, the electrical regulating means comprising switching means having successive electrically passing and electrically non-passing phases, the electrical regulating means being subjected to the switch-over rhythm of said switching means for generating a switched over electrical signal.

Abstract: An electro-welding device for electrically welding plastic elements together, comprising: a power source for having an AC current in circulation, an electrical converter AC/DC, heating means electrically connected to the converter for heating the weldable elements, electrical regulating means interposed between the electrical converter and the heating means, the electrical regulating means comprising switching means having successive electrically passing and electrically non-passing phases, the electrical regulating means being subjected to the switch-over rhythm of said switching means for generating a switched over electrical signal.

Abstract: It concerns butt-welding of parts made of plastics material(s). For this purpose, the invention proposes correcting, according to an ambient temperature which is measured in the environment of the parts at the moment of welding, at least one of the following parameters: pressure(s) for contact and/or welding of the parts, electrical energy to be supplied to means for displacement of the said parts, stroke(s) of relative displacement of the parts, time for obtaining beads at the end of the parts during the phase of heating the latter.