Automatic tool for the screwing and unscrewing of a screw of a flange between two pipes.

摘要

1. An automatic tool for screwing and unscrewing a screw or a nut (1) from a flange connection (2, 3) of two tubes (4, 5), comprising a spanner (17), which is adapted to be coupled to the head of the screw or of the nut and which is rotatively driven by a motor (19), characterized in that - that the motor (19) is mounted on a supporting structure (13) having a semi-annular shape adapted to the diameter of the tubes (4, 5), - and that the tool comprises : - a circular rail (8) fixed around one of the tubes (4) at a predetermined distance from the flanges (2, 3), - two wheels (9, 10) adapted to be guided by said rail (8) and movably mounted on a carriage (24) in the direction of the axis (6) of the tubes which carriage is articulated on said structure (13), - a third wheel (11) intended to be guided by said rail (8), movably mounted on said structure (13) in the direction of the axis (6) of the tubes, said three wheels being applied against said rail at regular angles when the carriage (24) is located in an operative position, whereas one of the wheels (10) is removed from the rail when the carriage is retracted about its axis of articulation (12), - means (15, 20) of the pneumatic, hydraulic or electromechanical type provided for the translational displacement of said supporting structure (13) relative to the wheels and parallel to the axis (6) of the tube, - a lever (21) of a semi-annular shape, articulated on said structure, the axis of articulation coinciding with the axis of rotation (28) of the spanner, and one end of the lever being coupled to a pneumatic piston (22) fixed to said structure (13) within a zone that is diametrically opposed to the spanner in relation to the axis of the tubes (6), said lever (21) being rotatively coupled to said spanner by means of reversible anti-return latch wheel systems (23).