Abstract: In an assembly station, a carcass sleeve and an outer sleeve manufactured along respective building lines are mutually coupled. Integrated into the assembly station are engagement devices that can be alternatively-coupled to an auxiliary drum carrying an outer sleeve and to a building drum carrying a carcass sleeve. The building drum is engaged on the assembly station before removal of the auxiliary drum. A grip unit picks up the outer sleeve from the auxiliary drum associated with the engagement devices in order to position it around the carcass sleeve carried by the building drum.