Patent ID: 8950292
Filing Date: 2015-02-10
Classification: B23P,B25B,Y02E

Abstract:
1. A rod tensioning device for tensioning a rod, the rod having a threaded portion, the rod tensioning device comprising: an actuator adapted to provide a tensioning axial force; a tie-rod adapted to transmit the tensioning axial force from the actuator to the threaded portion of the rod and including a plurality of jaws, the plurality of jaws being movable radially between a closed position at which the plurality of jaws are engaged with the threaded portion and an open position at which the plurality of jaws are disengaged from the threaded portion, each of the plurality of jaws having an outer surface; and a locking element including a sleeve slidable axially along the tie-rod and disposable about the plurality of jaws, the sleeve having an inner frustoconical surface contactable with the outer surfaces of the plurality of jaws, wherein each of the plurality of jaws includes a cylindrical portion having an internal threaded surface adapted to engage with the threaded portion of the rod and a frustoconical portion delimited by two edge guiding surfaces each having a stepped profile, wherein the sleeve includes three radially protruding elements, each of the three radially protruding elements being adapted to slide between the edge guiding surfaces of two adjacent jaws, and wherein each of the two edge guiding surfaces includes an upper surface section and a lower surface section, the plurality of jaws being arranged such that the upper surface sections of each pair of adjacent jaws define an upper guiding passage and the two lower surface sections of each pair of adjacent jaws define a lower guiding passage, each of the upper guiding passages being narrower than each of the lower guiding passages.