Side impact restraint device

[0001] The invention relates to a side impact restraint device for the protection of an occupant sitting on a vehicle seat in a motor vehicle.

[0002] From published German Patent Application DE 197 14 266 A1 a side impact restraint device is known with a gas bag which unfolds between a lateral structure of the vehicle and the occupant. The gas bag has two sections of differing width. The narrower upper section of the gas bag extends at the level of the chest region; the wider lower section extends at the level of the pelvic region.

[0003] Published Germ an Patent Application DE 100 20 729 A1 shows a gas bag which preferably unfolds from a vehicle seat and has outflow openings enabling a controlled escaping of the gas in case of an impact.

[0004] It is an object of the invention to provide a side impact restraint device with a gas bag which adapts itself to the physique of the occupant.

[0005] According to the invention a side impact restraint device in which the gas bag has an outflow opening which is arranged in a region of the gas bag facing the occupant, the vertical position of the outflow opening being selected so that it is not covered by the upper body (torso) of a small occupant. The arrangement of the outflow opening according to the invention causes the outflow opening to be covered by large occupants, so that a comparatively high internal pressure results, whereas in the case of small occupants the outflow opening is exposed, so that a comparatively low internal pressure is produced. The outflow opening therefore makes possible an individual adaptation of the restraint effect with the physique of the occupant.

[0006] Optimum test results are produced for an outflow opening which is located in a region which, in relation to the hip joint of the occupant, extends between a height of 400 mm and a height of 550 mm.

[0007] According to an advantageous embodiment of the invention, the gas bag has a further outflow opening which is arranged in a region of the lower section of the gas bag not facing the occupant. This, in any case, exposed outflow opening makes provision that the gas bag shape and the gas bag internal pressure can also adapt themselves individually to the physique of large occupants.

[0008] In order to prevent the gas emerging from the outflow opening from directly hitting the occupant, it is expedient to provide on the second outflow opening an arrangement for deflecting the outflowing gas.

[0009] According to a preferred embodiment of the invention, the gas bag in the inflated state, viewed in longitudinal direction of the vehicle, has an upper section and a lower section widened compared with the upper section, the lower section extending solely above the hip joint of the occupant. The widened design of the lower gas bag section, in particular in the case of occupants with a narrow upper body, makes provision that the gap between door lining and upper body is closed as quickly as possible. Accordingly, the restraint effect with such occupants begins earlier and is thereby carried out more effectively. Also with large occupants, in the case of a large distance between seat rest and door lining, the restraint effect can be improved compared with conventional cushion-shaped gas bags.

[0017] In FIG. 1 a part of a vehicle interior is illustrated, including a front seat 10 and a lateral structure 12 of the vehicle. The distance between the rest of the seat 10 and the lateral structure 12 (door lining or B-column) generally varies between 60 and 140 mm. In addition, an inflated gas bag 14 is shown for protection of a vehicle occupant from a side impact, the gas bag 14 having unfolded out from the seat rest 10. The gas bag 14 has an upper section 16 and a lower section 18, the width W of the lower section 18 exceeding the width w of the upper section 16.

[0018] In the FIGS. 2a and 2b, a differentiation is made between a small occupant 20a with a narrow upper body and a large occupant 20b with a wide upper body. It can be seen that the lower section 18 of the gas bag 14, irrespective of the size of the occupant, extends at the height of the thorax region. Owing to the widened construction of the lower section 18, on unfolding of the gas bag 14, in particular in the case of small occupants 20a with a narrow upper body, the relatively large gap between upper body and lateral structure 12 is quickly closed.

[0019] The gas bag 14 has in addition two outflow openings 22 and 24 (see FIG. 2a). The first outflow opening 22 is arranged in a region of the gas bag 14 not facing the occupant, more precisely in the front region of the lower section 18. The second outflow opening 24 is provided in a region of the upper section 16 of the gas bag 14 facing the vehicle occupant.

[0020] The vertical position of the second outflow opening 24 lies in a region 26, which is illustrated in hatched lines in FIGS. 4a, 4b and 5. This region 26, in relation to the hip joint 27 of an occupant 20a or 20b, extends between a height h₁ of 400 mm and a height h₂ of 550 mm.

[0021] From FIGS. 4a and 4b, it can further be seen that gas can always flow out from the first outflow opening 22 irrespective of the size of the occupant. On the other hand, the second outflow opening 24 is covered by large occupants 20b, whereas in the case of small occupants 20a, it remains free initially.

[0022] The first outflow opening 22 serves for adjusting the gas bag internal pressure specifically for large occupants 20b with a wide upper body. The possibility of gas emerging from the first outflow opening 22 allows a portion of the widened lower section 18 of the gas bag 14 to be able to be displaced (see FIGS. 2b and 3b). It has been found that for such occupants, a dynamic gas bag internal pressure of approximately 0.6 to 0.8 bar is optimal. In the case of small occupants 20a with a narrow upper body, the gas bag 14 substantially reaches its full expansion (see FIGS. 2a and 3a). As the second outflow opening 24 is not covered by a small occupant 20a, in this case the areas of the two outflow openings 22 and 24 are added up. Through the outflowing of gas from both outflow openings 22 and 24, an optimum dynamic gas bag internal pressure of approximately 0.3 to 0.4 bar for small occupants results. The gas bag internal pressure can therefore be controlled via the outflow openings 22 and 24 as a function of the size of the occupant.

[0023] To protect the occupant from the gas emerging from the second outflow opening 24 facing the occupant, a deflection arrangement is provided, shown in FIGS. 6a to 6c, which lies at least partially in the region 26 and is formed from a fabric piece 28. A first section 30 of the fabric piece 28 lies directly over the outflow opening 24 and has an opening 32 corresponding to the outflow opening 24. A second section 34, connected with the first section 30, is folded over such that it covers the two openings 24 and 32. The fabric layers 30 and 34 are sewn on two opposite sides onto the outer wall of the gas bag 14, so that the gas can only emerge on one side (see FIG. 6c). This side is selected so that it points away from the occupant.