Manipulator having an axially extendable arm, with casing, said arm bearing on a distal extremity a unit for temporarily coupling to a receiving unit, in order to be able to transmit to the latter a rotational movement and/or a translational movement along a common geometric axis (AA'), wherein: - the temporary coupling unit is equipped with at least one protruding element or at least one coupling cavity able to cooperate in a coupling relationship by means of a corresponding shape with at least one coupling cavity or one protruding element formed in the receiving unit, such that the coupling unit is able to transmit torque to the receiving unit; - the temporary coupling unit is coupled to the distal extremity of a shaft transmitting torque and movement, extending along the abovementioned geometric axis; - the transmission shaft is coupled to the rotary output shaft of a motor unit of the arm and borne by a mount that is mobile in translation and fixed in rotation, actuated by a second motor unit of the arm, the manipulator being characterized in that: - a locking member, having at the distal extremity at least one locking radial protrusion, is mounted on the transmission shaft so as to be fixed in translation relative to said shaft and with a limited scope of angular movement around the geometric axis (AA'); - a braking means, in the fully deployed position of the arm, acts on the locking member to prohibit the rotation of said locking member around the geometric axis (AA'); - the temporary coupling unit is able, by rotation of the receiving unit, to bring a locking radial protrusion that the receiving unit is fitted with behind and in front of the locking protrusion of the locking member, to provide a linkage in translation with the receiving unit, or is able to disengage this protrusion, to break the linkage in translation with the receiving unit and be able to detach the receiving unit from the temporary coupling unit by retracting the arm, the angular separation between the locking protrusions (12, 21) in the unlocked position being equal to or less than the range of the permitted angular movement of the locking member relative to the transmission shaft. - the temporary coupling unit is equipped with at least one protruding element or at least one coupling cavity able to cooperate in a coupling relationship by means of a corresponding shape with at least one coupling cavity or one protruding element formed in the receiving unit, such that the coupling unit is able to transmit torque to the receiving unit; - the temporary coupling unit is coupled to the distal extremity of a shaft transmitting torque and movement, extending along the abovementioned geometric axis; - the transmission shaft is coupled to the rotary output shaft of a motor unit of the arm and borne by a mount that is mobile in translation and fixed in rotation, actuated by a second motor unit of the arm, the manipulator being characterized in that: - a locking member, having at the distal extremity at least one locking radial protrusion, is mounted on the transmission shaft so as to be fixed in translation relative to said shaft and with a limited scope of angular movement around the geometric axis (AA'); - a braking means, in the fully deployed position of the arm, acts on the locking member to prohibit the rotation of said locking member around the geometric axis (AA'); - the temporary coupling unit is able, by rotation of the receiving unit, to bring a locking radial protrusion that the receiving unit is fitted with behind and in front of the locking protrusion of the locking member, to provide a linkage in translation with the receiving unit, or is able to disengage this protrusion, to break the linkage in translation with the receiving unit and be able to detach the receiving unit from the temporary coupling unit by retracting the arm, the angular separation between the locking protrusions (12, 21) in the unlocked position being equal to or less than the range of the permitted angular movement of the locking member relative to the transmission shaft.