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: A portable device for straightening out pipes including a hollow beam provided at its two ends with first and second movable bearing members, respectively, one of which or first movable bearing member is actuated by a jack housed within the hollow beam whereas a grip for handling the device is transversely and adjustably mounted on the beam between the first and second movable bearing members and carries a third movable bearing member, the device being applicable in particular for straightening out polyethylene tubes to be assembled end to end.