Sealing device for sealing a passage for a medical instrument

1. A sealing device for sealing a passage for a medical instrument, with:

a fastening area for fastening the sealing device on a tube or another medical appliance;

a sealing area which is at least either designed to bear on the circumference of a medical instrument inserted into the sealing device or is designed to close the sealing device when no medical instrument is inserted into the sealing device;

a first elastic wall enclosing the sealing area in a ring shape, with an annular first edge, which is connected to the sealing area, and an annular second edge;

a second elastic wall which encloses the first wall in a ring shape and is spaced apart therefrom, with an annular first edge and an annular second edge, which is connected to the fastening area;

an annular transition area, which connects the second edge of the first wall to the first edge of the second wall, wherein the transition area has a wall thickness greater than the first wall and greater than the second wall;

wherein the sealing area comprises a slit membrane for closing the sealing device when no medical instrument is inserted into the sealing device, and a ring seal designed to bear on the circumference of a medical instrument inserted into the sealing device; and

an outer edge of the slit membrane is arranged directly behind the ring seal with respect to the direction of insertion in which a medical instrument is to be inserted into the sealing device.

2. The sealing device according to claim 1 , in which the greatest wall thickness of the transition area is at least 50 percent greater than the minimum wall thickness of the second wall.

3. The sealing device according to claim 1 , in which the thickness of the first wall increases from the sealing area to the transition area.

4. The sealing device according to claim 1 , in which the thickness of the second wall increases from the transition area to the fastening area.

5. The sealing device according to claim 1 , in which the transition area, in a sectional plane containing an axis of symmetry of the first wall and of the second wall, has a substantially arc-shaped cross section.

6. The sealing device according to claim 1 , also with:

a reinforcement at an end of a slit in the slit membrane.

7. The sealing device according to claim 1 , also with:

a tab near the fastening area, for manually releasing the fastening of the sealing device on the tube or another medical appliance.

8. The sealing device according to claim 1 , wherein the sealing device is configured in one piece.

9. The sealing device according to claim 1 , also with:

a friction-reducing layer on a surface area that is designed to touch a medical instrument inserted into the sealing device.

10. A tube with a sealing device according to claim 1 .

11. The tube according to claim 10 , wherein the tube has, other than the sealing device, no further sealing device for closing the tube when a medical instrument is inserted into the tube or for closing the tube without an inserted medical instrument.

12. The sealing device according to claim 1 , wherein the slit membrane comprises three symmetrically arranged radial portions.

13. The sealing device according to claim 12 , further comprising a reinforcement at an end of each slit separating the radial portions.

14. The sealing device according to claim 1 , wherein the ring seal comprises an O-ring.