Gas bag arrangement with a device for controlling an outlet cross-section of a vent opening

1. A gas bag arrangement for a vehicle occupant restraint system, comprising

a gas bag inflatable by a gas generator to protect a vehicle occupant, whose envelope defines an interior space of the gas bag that can be filled with gas,

a vent opening through which gas can flow out of the gas bag, and

a device for controlling the outlet cross-section of the vent opening, which comprises at least one covering part with which the vent opening can be covered, in order to at least partly close the same, and which furthermore comprises an actuating mechanism which interacts with the covering part, in order to vary the outlet cross-section of the vent opening,

wherein the actuating mechanism includes an additional gas source and an element different from the gas bag and inflatable by means of the gas source, which during inflation interacts with the covering part such that it effects a change in the outlet cross-section of the vent opening, and

wherein the covering part is connected with the envelope of the gas bag by means of at least one fixed connection and a releasable connection and that the inflatable element is formed as an element different from the covering part which via the releasable connection likewise is connected with the envelope of the gas bag.

2. The gas bag arrangement according to claim 1 , wherein the releasable connection, the covering part and the inflatable element are formed such that during inflation of the inflatable element the releasable connection is released and the covering part can be lifted from the vent opening or be pushed through the vent opening by maintaining its fixed connection with the envelope of the gas bag.

3. The gas bag arrangement according to claim 1 , wherein the covering part is arranged between the inflatable element and the envelope of the gas bag.

4. The gas bag arrangement according to claim 1 , wherein the inflatable element is arranged adjacent to the vent opening.

5. The gas bag arrangement according to claim 1 , wherein the gas bag arrangement includes several vent openings.

6. The gas bag arrangement according to claim 5 , wherein the vent openings each are covered by a covering part.

7. The gas bag arrangement according to claim 1 , wherein via the releasable connection the inflatable element is connected with the envelope of the gas bag, via which the covering part also is connected with the envelope of the gas bag.

8. The gas bag arrangement according to claim 1 , wherein inflatable element interacts with at least two covering parts.

9. The gas bag arrangement according to claim 1 , wherein the covering part is fixed on the outside of the gas bag by the releasable connection at least one fixed connection such that the at least one fixed connection surrounds the vent opening in a closed contour.

10. The gas bag arrangement according to claim 9 , wherein the at least one fixed connection at least partly extends along the edge region of the covering part.

11. The gas bag arrangement according to claim 9 , wherein the closed contour of the at least one fixed connection is crossed by the releasable connection.

12. The gas bag arrangement according to claim 9 , wherein with the envelope of the gas bag the covering part forms a chamber closed to the outside due to the closed contour of the at least one fixed connection.

13. The gas bag arrangement according to claims 12 , wherein a valve mechanism is associated to the vent opening and the valve mechanism can be actuated in dependence on the filling of the chamber.

14. The gas bag arrangement according to claim 1 , wherein a valve mechanism is associated to the vent opening.

15. The gas bag arrangement according to claim 1 , wherein through the vent opening gas can flow out into a chamber arranged on the outside of the envelope of the gas bag.

16. The gas bag arrangement according to claim 1 , wherein during inflation the actuating mechanism interacts with the covering part such that it effects a change in the outlet cross-section of the vent opening to the effect that the vent opening is opened.