Patent ID: 7883117

Claim:
A screw coupling including a locking device, said screw coupling comprising first and second components rotatable in relation to one another during screwing and unscrewing, the first component comprising a first thread and a rotating engagement formation distant from the first thread, the locking device being mounted on the second component and comprising: a coupling component for coupling with the engagement formation, a stop component connected for common rotation with a body carried by the second component, the body connected for common rotation with the second component, and disconnectable coupling means between the coupling component and the stop component, wherein the disconnectable coupling means comprises a ratchet allowing relative rotation in the direction of unscrewing when a torque at least indirectly applied to the coupling component and the stop component with respect to one another overcomes a predetermined elastic resistance, the torque between the coupling component and the stop component resulting from a torque applied between the first component and the body.