relates to a ball coupler having a longitudinal axis and comprising a male tubular endpiece a female tubular endpiece a tubular sleeve extending the female endpiece and presenting slots for forming a cage for retaining balls for blocking the male endpiece in the female endpiece and a grip coaxial about the sleeve and mounted to thereon to turn about the longitudinal axis of the coupler between at least two angular positions relative to the sleeve said grip possessing means for housing each ball and resilient return means for urging the grip into its first position which means comprise in the grip a ring that is constrained to turn with the grip and that is movable axially relative thereto said ring presenting two end surfaces one of which faces towards a shoulder of the sleeve for slidably bearing thereagainst to co operate in reversibly transforming turning movement of the grip into an axial movement of the ring relative to said grip and the other of which forms the bearing face for a compression spring tending to urge said ring against said shoulder application_number US 17427408 A description with reference to fig1 and 2 the ball coupler constituting a first embodiment of the invention about a longitudinal axis 1 comprises a male tubular endpiece given.