Patent Number: 050698621
Section: summary

FIELD OF THE INVENTION The present invention relates to an apparatus for handling a machine for the tensioning of screwed connecting elements, such as bolts or pins. BACKGROUND OF THE INVENTION In industrial installations using screwed connecting elements, a pull is exerted on the said elements during clamping and releasing operations by pull is exerted on the said elements by means of a tensioning machine for the purpose of keeping the elements in the prestressed state. This applies to pressurized vessels, such as vessels of nuclear reactors, where the cover is fastened removably to the vessel, in order to allow periodic refuelling of the nuclear reactor and, via this cover, inspection of the interior of the vessel and the elements located inside it. For this purpose, the cover is fastened to the vessel of the reactor by means of pins which are screwed into the flange of the vessel and which penetrate into smooth holes made in the flange of the cover. These pins are usually used in somewhat large numbers and are relatively close to one another, with the result that the removal and refitting of the cover requires the unscrewing and screwing of all these pins after the prestressed state obtained by means of the tensioning machine has been relieved. Tensioning machines composed of a set of hydraulic tensioners fastened and distributed in polar symmetry on a carrier ring are known, for example, from FR-A-2,329,414 and FR-A-2,274,997. The hydraulic tensioners act simultaneously and ensure the desired prestress on each pin. These machines generally have a bulky infrastructure consisting of a one-piece carrier ring, thus making it impossible to install them when the vessel of the nuclear reactor is located in a relatively restricted environment surrounded by non-removable elements. SUMMARY OF THE INVENTION The object of the invention is, therefore, to provide an apparatus for handling a machine for the tensioning of screwed connecting elements, making it possible to do without any environment consisting of non-removable elements and to take action without full participation of the polar bridge of the vessel, thus substantially reducing the cost of this type of action. According to the invention, the apparatus for handling a machine for the tensioning of screwed connecting elements consisting especially of bolts or pins intended, for example, for the fastening of a cover of a vessel comprises at least one tensioning module for the connecting elements, means for the movement of this tensioning module in a horizontal plane, and means for the movement of the said tensioning module in the vertical axis of the connecting elements. According to other characteristics of the invention: means for the horizontal movement of the tensioning module consist of assembled modular elements forming a rolling track, on which travels a train supporting the said tensioning module, the train comprises a driving carriage and a driven carriage, each equipped with a set of guide wheels and connected to one another by means of a strut, and the means for the vertical movement of the tensioning module consist of a vertical endless screw mounted for free rotation on each carriage and of a nut screwed onto each of the endless screws and each connected to the said tensioning module by means of a bracket.