Multi-chamber airbag

1 . A multi-chamber airbag, comprising

an airbag wall enclosing an inflatable primary chamber, and

a gas distribution mechanism,

wherein the airbag wall has a primary outlet and at least one secondary outlet,

wherein the gas distribution mechanism has a primary closure element and at least one secondary closure element,

wherein the gas distribution mechanism can be adjusted between a first position in which the multi-chamber airbag is inflated to a first state and a second position in which the multi-chamber airbag is inflated to a second state, and

wherein the multi-chamber airbag is configured so that, in the first position, the primary outlet is closed by the primary closure element so that no gas can flow out of the primary chamber via the primary outlet, and the at least one secondary outlet is released so that gas can flow out of the primary chamber via the at least one secondary outlet, and in the second position the primary outlet is released so that gas can flow out of the primary chamber via the primary outlet, and the at least one secondary outlet is closed by the at least one secondary closure element so that no gas can flow out of the primary chamber via the at least one secondary outlet.

2 . The multi-chamber airbag according to claim 1 , wherein the multi-chamber airbag includes a secondary chamber and a tertiary chamber, wherein the primary chamber in the first position of the gas distribution mechanism is fluid-connected via the secondary outlet to the tertiary chamber, and the primary chamber in the second position of the gas distribution mechanism is fluid-connected via the primary outlet to the secondary chamber.

3 . The multi-chamber airbag according to claim 2 , wherein the multi-chamber airbag includes a baffle which in the installed and deployed state of the multi-chamber airbag faces an associated vehicle occupant, and a circumferential wall which is connected to the baffle and extends, in the installed and deployed state of the multi-chamber airbag, between the baffle and a vehicle component to which the multi-chamber airbag is attached, wherein the circumferential wall at least partially has a multi-layer design and in the first state forms at least one annular tube which defines the tertiary chamber, and wherein a radially inner layer of the circumferential wall together with the baffle delimits the secondary chamber.

4 . The multi-chamber airbag according to claim 3 , wherein the at least one annular tube in the first state has a circular tube cross-section and in the second state is axially tensile-loaded so that the radially inner layer and a radially outer layer of the circumferential wall are mutually abutting and extend in the axial direction.

5 . The multi-chamber airbag according to claim 3 , wherein an axial distance (A 1 , A 2 ) between the baffle and the vehicle component is larger in the second state than in the first state.

6 . The multi-chamber airbag according to claim 3 , wherein the primary chamber includes a gas source-side inlet opening and in the main deployment direction (H) abuts on the secondary chamber as well as is circumferentially delimited by the tertiary chamber.

7 . The multi-chamber airbag according to claim 2 , wherein the tertiary chamber has at least one portion which encloses the secondary chamber in ring shape.

8 . The multi-chamber airbag according to claim 2 , wherein the at least one secondary closure element in the second position extends out of the primary chamber through the primary outlet into the secondary chamber.

9 . The multi-chamber airbag according to claim 1 , wherein the airbag wall includes a one-piece airbag portion in which the primary outlet and the at least one secondary outlet are disposed.

10 . The multi-chamber airbag according to claim 1 , wherein the multi-chamber airbag includes plural secondary outlets and a corresponding number of secondary closure elements each being associated with one of the secondary outlets.

11 . The multi-chamber airbag according to claim 10 , wherein the secondary outlets are disposed in ring shape around centrically disposed primary outlet.

12 . The multi-chamber airbag according to claim 1 , wherein the at least one secondary closure element is secured to the primary closure element.

13 . The multi-chamber airbag according to claim 12 , wherein the at least one secondary closure element includes an elongate retaining end at which the at least one secondary closure element is secured to the primary closure element, an oppositely disposed securing end at which the at least one secondary closure element is secured to the airbag wall, and a closure portion for closing the associated secondary outlet, the multi-chamber airbag being designed such that in the first position the closure portion is disposed spaced apart from the associated secondary outlet and that the closure portion overlaps and thus closes the associated secondary outlet when the multi-chamber airbag is inflated to the second state.

14 . The multi-chamber airbag according to claim 1 , wherein the primary closure element is formed of two superimposed cut portions each being fan-shaped or bell-shaped as well as having an elongate end and an oppositely disposed circumferential edge at which the cut portion is secured to the airbag wall, wherein the cut portions are sewn up to each other at the elongate end as well as to a respective boundary area in the area of the circumferential edge, wherein the cut portions are not connected over a major part of lateral edges located between the elongate end and the circumferential edge so that two lateral discharge openings are formed in the primary closure element.

15 . The multi-chamber airbag according to claim 1 , wherein the primary closure element in the second position is completely disposed in the secondary chamber.

16 . The multi-chamber airbag according to claim 15 , wherein the primary closure element in the first position extends out of the secondary chamber through the primary outlet into the primary chamber.

17 . The multi-chamber airbag according to claim 1 , wherein the at least one secondary closure element in the first position is completely disposed in the primary chamber.

18 . The multi-chamber airbag according to claim 1 , wherein the gas distribution mechanism includes a retaining device which is adjustable between a retaining position and a released position, wherein the multi-chamber airbag is designed so that, in the released position, the primary closure element and the at least one secondary closure element are disconnected from the retaining device, and in the retaining position the primary closure element and the at least one secondary closure element are secured to the retaining device.