Closure device for the vacuum-tight closing of an opening in a wall

1. A closure device for closing an opening in a wall in a vacuum-tight manner, comprising:

a closure plate which, for the purpose of closing the closure device, is displaceable from an open position, in which the opening is released, to an intermediate position in which it covers the opening but is raised from the wall, into a closed position in which it covers the opening and contacts the wall and, for the purpose of opening the closure device, is displaceable from its closed position to its intermediate position into its open position;

a carrying unit which carries the closure plate and which has at least one longitudinal piston-cylinder unit by which the closure plate can be displaced in closing direction from its intermediate position into its closed position and in an opening direction from its closed position into its intermediate position and which has a closing cylinder space for applying pressure to a closing piston surface by pressure gas in order to exert a force acting in closing direction and an opening cylinder space for applying pressure to an opening piston surface by pressure gas in order to exert a force acting in opening direction;

a base unit which carries the carrying unit and has at least one transverse piston-cylinder unit by which the closure plate is displaceable in a closing direction from its open position to its intermediate position and in an opening direction from its intermediate position into its open position and which has a closing cylinder space for applying pressure to a closing piston surface by pressure gas in order to exert a force acting in closing direction and an opening cylinder space for applying pressure to an opening piston surface by pressure gas in order to exert a force acting in opening direction;

said closing cylinder space of the at least one longitudinal piston-cylinder unit being connected to the closing cylinder space of the transverse piston-cylinder unit, or of at least one of the transverse piston-cylinder units, by a closing pressure gas channel, and the opening cylinder space of the at least one longitudinal piston-cylinder unit being connected to the opening cylinder space of the transverse piston-cylinder unit, or of at least one of the transverse piston-cylinder units, by an opening pressure gas channel;

said closing cylinder spaces and the opening cylinder spaces of the transverse piston-cylinder units and longitudinal piston-cylinder units being acted upon by pressure for closing the closure device; and only the opening cylinder spaces of the transverse piston-cylinder units and longitudinal piston-cylinder units being acted upon by pressure for opening the closure device;

said closing piston surface of the at least one transverse piston-cylinder unit being greater than the opening piston surface of the at least one transverse piston-cylinder unit;

said closing piston surface of the at least one longitudinal piston-cylinder unit being greater than the opening piston surface of the at least one longitudinal piston-cylinder unit; and

the ratio between the closing piston surface and the opening piston surface of the at least one transverse piston-cylinder unit being greater than the ratio between the closing piston surface and the opening piston surface of the at least one longitudinal piston-cylinder unit.

2. The closure device according to claim 1 , wherein the closing pressure gas channel leads through a piston rod of the transverse piston-cylinder unit or one of the transverse piston-cylinder units.

3. The closure device according to claim 2 , wherein the piston rod, through which the closing pressure gas channel leads, is tubular and the closing pressure gas channel leads through the open end of this piston rod remote of the carrying unit into the interior of this piston rod.

4. The closure device according to claim 1 , wherein the opening pressure gas channel leads through a piston rod of the transverse piston-cylinder unit or of one of the transverse piston-cylinder units.

5. The closure device according to claim 4 , wherein this piston rod of the transverse piston-cylinder unit is tubular and the opening pressure gas channel leads through a bore hole penetrating the wall of the piston rod into the interior of this piston rod.

6. The closure device according to claim 1 , wherein the closing pressure gas channel and the opening pressure gas channel lead through piston rods of different transverse piston-cylinder units.

7. The closure device according to claim 1 , wherein a portion of the closing pressure gas channel and a portion of the opening pressure gas channel are formed, respectively, by a transverse bore hole in the carrying unit.

8. The closure device according to claim 1 , wherein the carrying unit, to form the longitudinal piston-cylinder unit or a respective longitudinal piston-cylinder unit, has a cylindrical chamber in which a dual-action piston is arranged and which delimits the opening cylinder space from the closing cylinder space.

9. The closure device according to claim 1 , wherein the base unit, to form the transverse piston-cylinder unit or a respective transverse piston-cylinder unit, has a cylindrical chamber in which a dual-action piston is arranged and which delimits the closing cylinder space from the opening cylinder space.

10. The closure device according to claim 1 , wherein the closure device has a closing pressure gas connection and an opening pressure gas connection which are connected to two inputs of an OR-valve whose output is connected to the opening cylinder space of the at least one transverse piston-cylinder unit.

11. The closure device according to claim 10 , wherein at least one connection channel proceeds from a pressure gas channel connecting the closing pressure gas connection to the OR-valve and opens into the closing cylinder space of the at least one transverse piston-cylinder unit.

12. The closure device according to claim 1 , wherein the ratio between the closing piston surface and the opening piston surface of the at least one transverse piston-cylinder unit is at least 70% greater than the ratio between the closing piston surface and the opening piston surface of the at least one longitudinal piston-cylinder unit.