The invention relates to a door actuator, in particular the door lock, for rail vehicles, comprising a spindle drive, the spindle of which is connected to a freewheel, permitting rotation in the direction corresponding to the closing of the door and preventing rotation in the direction corresponding to the opening of the door. The part of the freewheel (1) furthest from the spindle is mounted such as to rotate, but with a releasable fixing relative to a release device (2), achieved by means of a coupling (3, 6) which may be released by means of a solenoid (8). The invention is characterised in that the brake, coupling or similar is or may be fixed in the open position and a closing magnet is provided. In a first version, the coupling (3, 6) is operated by means of a bar (9), and between the released position of the bar (9) and the locked position of the bar (9) there is a dead-point. In a second version, the open position is maintained by a permanent magnet.