System for locking a coupling of elements, having male and female ends

A locking system comprising:

• a male cylindrical end of a first element and a female tubular cylindrical end of a second element, the male cylindrical end being engaged inside the female tubular cylindrical end to couple the first element to the second element,
• wherein:
• a locking groove is hollowed in an outer surface of the male cylindrical end,
• the female tubular cylindrical end is bored on a side with a through-opening inside of which is arranged a mobile locking element that protrudes from inside the female tubular cylindrical end and into the locking groove of the male cylindrical end, and
• a locking ring is mounted, free in rotation around the female tubular cylindrical end, on an outer surface of the female tubular cylindrical end opposite the through-opening, the locking ring having an inner surface with a recess having an ortho-radially variable depth that enables locking/unlocking of the mobile locking element against the locking groove depending on a position of the locking ring,
• wherein the locking groove extends in an axial direction of the male cylindrical end from an axial free end thereof, and wherein the mobile locking element is moves within the locking groove from the axial free end in order to guide and angularly limit the insertion of the male cylindrical end in the female tubular cylindrical end.