Device for the sealed connection between a first and a second closed space, with the first closed space comprising openings closed off by a door, comprising: first part (A) for securing two closed spaces, second part (B) for securing two doors and of unlocking one of the door, third part (C) for releasing the other door, fourth part (D) for opening a passage between the two closed spaces, a control ring (48) able to be put into rotation around a longitudinal axis (X), with the rotation of the control ring (48) actuating at least the second (B), third (C) and fourth (D), parts, and a device for actuating the control ring and first means.