Clearance blocking device and use of such a clearance blocking device

摘要

The device has a blocking unit (44) extending in a gap (34) from a wall section (31) and movable transverse to the gap. The blocking unit has a piston surface (60) that is guided in the wall section and a leak proof structure opposite to the piston surface. The leak proof structure is pressed by using a pressure medium (D) acting on the piston surface at a leak proof area (56) of a wall section (32).