The device has a closure plate (7) with an inner and outer side in which is constructed a longitudinal opening (19) for receiving a lock bolt. A pressure plate (2) is attached to the inner side which partly covers the opening. The opening extends parallel to the length of the closure plate. The side edge of the pressure plate enclosing the lock bolt receiver opening also runs parallel to the closure plate. The location of the side edge of the pressure plate is adjustable. The pressure plate is inclined against the inner side of the closure plate in such a way that it extends at an angle from a region near the inner side next to the opening to the part of the inner side over which the opening extends.
