Leaktight joining device intended for ensuring the aseptic transfer of a biopharmaceutical product between a chamber equipped with a removable door and a container equipped a removable cover, comprising: stationary temporary clamping means able to keep the container clamped against the chamber so that the removable cover of said container is sealingly held against the removable door of said chamber; stationary unlocking means able to transition the container from an initial locking position where the removable cover seals the container to an intermediate unlocking position where the removable cover is disengaged from the container and is sealingly held against the removable door of the chamber so as to ensure an aseptic communication between said container and said chamber; stationary locking means able to transition the container from the intermediate unlocking position to a final locking position where said removable cover once again seals the container; an annular functional ring gear able to rotate about a geometric axis of rotation so as to actuate the stationary unlocking means and the stationary locking means of the container; characterized in that the stationary temporary clamping means, stationary unlocking means, and stationary locking means are mechanically linked to the annular functional ring gear and are arranged so that the one-way rotation of said annular functional ring gear about the geometric axis of rotation successively causes the actuation of the stationary temporary clamping means which ensures that the container is held in position against the chamber, then the actuation of the stationary unlocking means which ensures the transition to the intermediate unlocking position of the container, then the actuation of the stationary locking means of the container which ensures the transition to the final locking position of the container, and the actuation of the stationary temporary clamping means of the container in order to release the container. stationary temporary clamping means able to keep the container clamped against the chamber so that the removable cover of said container is sealingly held against the removable door of said chamber; stationary unlocking means able to transition the container from an initial locking position where the removable cover seals the container to an intermediate unlocking position where the removable cover is disengaged from the container and is sealingly held against the removable door of the chamber so as to ensure an aseptic communication between said container and said chamber; stationary locking means able to transition the container from the intermediate unlocking position to a final locking position where said removable cover once again seals the container; an annular functional ring gear able to rotate about a geometric axis of rotation so as to actuate the stationary unlocking means and the stationary locking means of the container; characterized in that the stationary temporary clamping means, stationary unlocking means, and stationary locking means are mechanically linked to the annular functional ring gear and are arranged so that the one-way rotation of said annular functional ring gear about the geometric axis of rotation successively causes the actuation of the stationary temporary clamping means which ensures that the container is held in position against the chamber, then the actuation of the stationary unlocking means which ensures the transition to the intermediate unlocking position of the container, then the actuation of the stationary locking means of the container which ensures the transition to the final locking position of the container, and the actuation of the stationary temporary clamping means of the container in order to release the container.