Abstract: Revolving door having at least four variable length door wings extending radially into a passageway, and being offset from one another in the direction of rotation about a central axis. Each door wing includes at least two sliding door elements slidingly movable relative to each other to vary the radial length of the door wings. Each door wing has a pivot axis disposed radially outwardly from the central axis. Adjacent door wings are pivotable about their respective pivot axes from an operating position in which the door wings extend radially into the passageway to an open position in which the sliding door elements slide relative to each other to shorten the radial length and unblock the passageway.

Abstract: The electro-mechanical drive includes an electric motor, a transmission and a restoring spring. To improve the capacity to close the door, particularly in the event of a power failure, a large coil spring used as the restoring spring surrounds the electric motor and transmission. The electric motor is short circuited when not powered in order to create a generator effect with consequent damping during movement of the door.