Passenger seat device for vehicles, railway vehicle with a passenger seat device and method for customizing the available seating space of a railway vehicle

The device (100) has a seat (111) firmly mountable in a vehicle. Another seat (121) is movable relative to the former seat. The latter seat is connected with the former seat. The latter seat is swingable around a vertically extending pivotal axle (130) relative to the former seat between two positions. The second seat is foldable in a region of the former seat in one position. The second seat is available for use by a passenger in another position. A power unit e.g. pneumatic drive, moves the second seat between the two positions. Independent claims are also included for the following: (1) a rail vehicle (2) a method for adjusting seat capacity of a rail vehicle.