A device for coupling a tube, comprising: - a hollow body defining a housing which comprises an opening through which a tube is intended to be inserted by sliding according to a direction of insertion, the housing is delimited by an inner surface of the hollow body, and which has a rotational symmetry about a main axis parallel to the direction of insertion; - a locking ring arranged in the housing coaxially to the direction of insertion and intended to be engaged with a tube inserted into the housing; - a first stop arranged in the housing and upstream of the locking ring according to the direction of insertion, and against which said ring is able to abut; - a cartridge against which the tube, inserted by a predetermined length and engaged with the locking ring, is intended to abut in order to impose a connection state on said cartridge, the cartridge in the connection state being able to slide between first and second positions in order to accompany the sliding of the tube engaged with the locking ring, the passage of the cartridge from the second to the first position imposing on the tube to slide according to a direction of extraction, opposite to the direction of insertion, in order to stop the locking ring against the first stop, whereas the passage of the cartridge from the first to the second position enables a sliding of the tube according to the direction of insertion in order to place the locking ring at a distance from the first stop, the cartridge comprising a sleeve which extends from a free end in the direction of insertion, and which is intended to ensure the guidance of the tube during the insertion of the latter into the housing, the coupling device comprising at least one locking means, the cartridge being able to be held, by the locking means, in a so-called locked state, and wherein any sliding of the cartridge towards the second position is prohibited, the passage from the locked state towards the connection state being induced by the insertion, according to the direction of insertion, of a tube length equal to the predetermined length; - a spring exerting a force against the cartridge according to the direction of extraction in order to impose on the cartridge, in the connection state, to adopt its first position. - a hollow body defining a housing which comprises an opening through which a tube is intended to be inserted by sliding according to a direction of insertion, the housing is delimited by an inner surface of the hollow body, and which has a rotational symmetry about a main axis parallel to the direction of insertion; - a locking ring arranged in the housing coaxially to the direction of insertion and intended to be engaged with a tube inserted into the housing; - a first stop arranged in the housing and upstream of the locking ring according to the direction of insertion, and against which said ring is able to abut; - a cartridge against which the tube, inserted by a predetermined length and engaged with the locking ring, is intended to abut in order to impose a connection state on said cartridge, the cartridge in the connection state being able to slide between first and second positions in order to accompany the sliding of the tube engaged with the locking ring, the passage of the cartridge from the second to the first position imposing on the tube to slide according to a direction of extraction, opposite to the direction of insertion, in order to stop the locking ring against the first stop, whereas the passage of the cartridge from the first to the second position enables a sliding of the tube according to the direction of insertion in order to place the locking ring at a distance from the first stop, the cartridge comprising a sleeve which extends from a free end in the direction of insertion, and which is intended to ensure the guidance of the tube during the insertion of the latter into the housing, the coupling device comprising at least one locking means, the cartridge being able to be held, by the locking means, in a so-called locked state, and wherein any sliding of the cartridge towards the second position is prohibited, the passage from the locked state towards the connection state being induced by the insertion, according to the direction of insertion, of a tube length equal to the predetermined length; - a spring exerting a force against the cartridge according to the direction of extraction in order to impose on the cartridge, in the connection state, to adopt its first position.