Abstract: A method of establishing and checking the axial preload in a tightening portion (34) of at least one shank of the screw or stud type (4). The establishing of the preload involves a step of tensioning an extension portion (33) of the shank (4) comprising the tightening portion (34) using a shank (4) gripper member (9) and a tensioner (6). The checking method involves a step in which, prior to establishing the preload, the tensioner is brought into a rest configuration and the gripper member (9) is brought into contact with the tensioner (6) in said rest configuration, and a step in which, having established the preload, the tensioner is returned to said rest configuration, and the tensioner in said rest configuration is pressed toward one of the ends of the extension portion (33) and the difference between the initial length (Li?) and the final length (Lf?) of the extension portion (33) is compared against a threshold.

Abstract: In a method for controlling tensile stress of a clamping rod, such as a screw or pin, by the axial extension of the rod and the positioning of at least one retaining member, before the rod is released, such that the latter is blocked at the two ends of the useful clamping length with a residual clamping tensile force, measurements are made which represent the elongation of the rod in the stretched state under a measured extension force and of the rod after release in relation to the rod before extension, by comparing values supplied by at least one sensor during extension and after release with a reference value supplied by this sensor before extension, and, on the basis of these data, a residual clamping force in the useful clamping length of the released rod after extension is calculated.

Abstract: A method of establishing and checking the axial preload in a tightening portion (34) of at least one shank of the screw or stud type (4). The establishing of the preload involves a step of tensioning an extension portion (33) of the shank (4) comprising the tightening portion (34) using a shank (4) gripper member (9) and a tensioner (6). The checking method involves a step in which, prior to establishing the preload, the tensioner is brought into a rest configuration and the gripper member (9) is brought into contact with the tensioner (6) in said rest configuration, and a step in which, having established the preload, the tensioner is returned to said rest configuration, and the tensioner in said rest configuration is pressed toward one of the ends of the extension portion (33) and the difference between the initial length (Li?) and the final length (Lf?) of the extension portion (33) is compared against a threshold.

Abstract: In a method for controlling tensile stress of a clamping rod, such as a screw or pin, by the axial extension of the rod and the positioning of at least one retaining member, before the rod is released, such that the latter is blocked at the two ends of the useful clamping length with a residual clamping tensile force, measurements are made which represent the elongation of the rod in the stretched state under a measured extension force and of the rod after release in relation to the rod before extension, by comparing values supplied by at least one sensor during extension and after release with a reference value supplied by this sensor before extension, and, on the basis of these data, a residual clamping force in the useful clamping length of the released rod after extension is calculated.

Abstract: The invention relates to a device for tensioning a threaded rod (1). The inventive device comprises: an actuator (5) which can exert an axial force; and a tie rod (6) which transmits the axial force from the actuator (5) towards a threaded end (1b) of the rod (1b), said tie rod (6) comprising at least two jaws (31) which can move radially between a closed position, in which the tie rod (6) is engaged with a threaded end (1b) of the rod (1), and an open position in which the jaws (31) are disengaged from the threaded rod (1b). Moreover, said device comprises a locking element (45) which can move between a jaw (31) opening position and a jaw (31) closing position.

Abstract: The invention relates to a device for tensioning a threaded rod (1). The inventive device comprises: an actuator (5) which can exert an axial force; and a tie rod (6) which transmits the axial force from the actuator (5) towards a threaded end (1b) of the rod (1b), said tie rod (6) comprising at least two jaws (31) which can move radially between a closed position, in which the tie rod (6) is engaged with a threaded end (1b) of the rod (1), and an open position. in which the jaws (31) are disengaged from the threaded rod (1b). Moreover, said device comprises a locking element (45) which can move between a jaw (31) opening position and a jaw (31) closing position.

Abstract: A double-twist twister mechanism includes a pair of assemblies which rotate about oblique intersecting axes, support a nonrotating spool carrier and have portions extending through each other. The assemblies are connected together for concurrent rotation by an external elastic member which is passable over the spool carrier into engagement with concentrically arranged fasteners on both assemblies.

Abstract: Spring 1 having principal undulations 2 inside which are formed windows 5 for the passage of cams 10, and secondary undulations 4. The cams are wedged between the edges 6 and 7 of these windows. The swinging of the cams is caused by the action of the swinging tongue 15 having a flat portion 17. An improvement in the synchronization of movement of the cams and a reduction in the wear of the device is obtained.