Abstract:
An assembly consists of a vehicle door, an A-pillar of a vehicle and an inflatable gas bag. In the inflated condition the gas bag is supported by the vehicle door and in the region of the A-pillar of the vehicle. The internal overpressure exceeds 10 5  Pa (14, 5 psi) in at least one part of said inflated gas bag.

Description:
FIELD OF THE INVENTION  
         [0001]    The invention relates to an assembly consisting of a vehicle door, an A-pillar of a vehicle and an inflatable gas bag.  
         BACKGROUND OF THE INVENTION  
         [0002]    Gas bags have a proven record of success in restraint systems to protect the vehicle occupant from injuries due to, for example, the vehicle being involved in a head-on collision. To offer protection also in the case of a side-impact collision or toppling of the vehicle, side gas bags are employed. Such gas bags are known which prior to deployment are accommodated in the roof structure or A-pillar of the vehicle and are stabilized via arresting devices to the vehicle parts. Likewise known are gas bags which prior to deployment are accommodated in the vehicle door and may be supported deployed by the B-pillar of the vehicle and/or windowsill.  
           [0003]    When the vehicle is involved in an accident it is very often the case that the side windows of the vehicle are shattered and thus no longer afford any supporting effect so that a side gas bag needs to not only deplete the movement energy of the vehicle occupant in avoiding injury but also to prevent the vehicle occupant, his head or hands from being catapulted outwards from the vehicle.  
           [0004]    On vehicles having no roof contour, especially convertibles, this protection is most important. At the same time, however, difficulties materialize in providing the gas bag with adequate stability, due to the lack of the vehicle roof structure, since it is obvious that conventional gas bags deploying from the door and supported by the B-pillar, roof or window frame cannot be made use of in this case.  
         BRIEF SUMMARY OF THE INVENTION  
         [0005]    The object of the invention is to provide a gas bag for vehicles having no roof contour which is capable of preventing the vehicle occupant from being catapulted outwards. For this purpose in an assembly consisting of a vehicle door, an A-pillar of a vehicle and an inflatable gas bag the gas bag in an inflated condition is supported by the vehicle door and in a region of the A-pillar of the vehicle. The internal overpressure exceeds 1 Pa (14, 5 psi)in at least one part of the inflated gas bag. The gas bag gains the necessary stability from the support in the region of the A-pillar and preferably at the windowsill, i.e. by the gas bag being supported either by the A-pillar itself or by the section of the door frame located in the vicinity of the A-pillar. This stabilizes the gas bag in the region between windowsill and A-pillar. The high internal overpressure in the gas bag ensures that also the exposed, i.e. non-supported portion of the gas bag does not give way outwards in cushioning a vehicle occupant or part of his body.  
           [0006]    Advantageously, the gas bag is fabricated so as to be gas-tight, i.e. the material of the gas bag itself being gas-tight and the gas bag having no gas-exit ports. Since the compressed gas is unable to escape from the gas bag, the gas bag maintains its shape and the high internal overpressure over a considerable period of time, preferably longer than 5 seconds. This thus maintains the protection for the vehicle occupant even when the vehicle topples.  
           [0007]    In one preferred embodiment of the invention the vehicle door comprises a windowsill and the gas bag is supported along the majority of the windowsill, this large supporting surface area of the gas bag on the windowsill ensuring enhanced stability. It is good practice when the gas bag is fabricated to extend far up to the front side of the door to prevent the hands of the vehicle occupant from being catapulted outwards from the vehicle. For this purpose the gas bag is shaped so that particularly the forward window area is covered practically completely, thus also enabling the gas bag to gain maximum possible stability from being supported at the A-pillar and windowsill. Preferably the gas bag extends likewise up to the vehicle rear end of the windowsill to also provide head protection for the vehicle occupant.  
           [0008]    In a further preferred embodiment of the invention the gas bag comprises two chambers, the first, outer chamber of which is configured tubular and has a high internal overpressure and the second, inner chamber is cushion-shaped and has a lower internal overpressure, the first, outer chamber surrounding the second, inner chamber. The outer chamber forms a stable frame due to its high internal overpressure endowing the gas bag with the necessary stability and by which the gas bag is supported at the A-pillar and at the windowsill. The inner chamber is configured as a cushion having a lower internal overpressure so that a vehicle occupant catapulted into the gas bag does not rebound therefrom but is softly cushioned therein. It is in this way that the necessary stability can be combined with the necessary pliancy of the gas bag. Preferably, the outer chamber and the inner chamber are not in flow connection with each other. Thus, the frame formed by the outer chamber retains its stability during the entire time the gas bag is inflated.  
           [0009]    In the folded condition the gas bag can be accommodated in the windowsill or in the A-pillar. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    [0010]FIG. 1 a  is a side view of a first embodiment of the invention,  
         [0011]    [0011]FIG. 1 b  is a front view of the assembly as shown in FIG. 1 a,    
         [0012]    [0012]FIG. 2 a  is a side view of a second embodiment of the invention, and  
         [0013]    [0013]FIG. 2 b  is a front view of the assembly as shown in FIG. 2 a.   
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0014]    Referring now to FIGS. 1 a  and  1   b  there is illustrated the assembly in accordance with the invention comprising a vehicle door  10 , the portion of the A-pillar  12  of a vehicle and a gas bag  14 . The vehicle door  10  incorporates a windowsill  16 .  
         [0015]    Prior to deployment the gas bag  14  is preferably accommodated in the vehicle door  10 . When the vehicle is involved in an accident, for example, in head-on collision with an obstacle, the gas bag  14  is activated by a sensor (not shown) and inflated by compressed gas from an inflator (not shown). The gas bag  14  is shown in this inflated condition in all Figures.  
         [0016]    The gas bag  14  itself is made of a gas-tight material and comprises no gas-exit ports or vents. The seal of the gas bag  14  is fabricated so that it maintains a high internal overpressure over a longish period of time (approx.  5  seconds), the internal overpressure being preferably in excess of 10 5  Pa (14, 5 psi).  
         [0017]    The gas bag  14  extends along the windowsill  16  so that the majority of the side window  18  is covered by the gas bag  14 . More particularly the gas bag  14  extends up to the front side of the side window  18  in the direction of the forward end of the vehicle to permit cushioning the hands and lowers arms of a vehicle occupant in preventing them from being catapulted outwards from the vehicle. The gas bag  14  likewise utilizes a further section of the A-pillar  12  or corresponding section of the door frame for support, thus resulting in two surface area supports  20 ,  22  for the gas bag  14  endowing it with stability.  
         [0018]    It may be provided for that the gas bag is shaped for being supported by the windowsill  16  so that it comprises in the inflated condition a rim  24  resting on the windowsill  16 . This rim or kink  24  in the contour of the gas bag  14  prevents the gas bag  14  from being displaced downwards.  
         [0019]    Due to the high internal overpressure and the support as may be provided the free end  26  of the gas bag  14  not supported by the A-pillar  12  or windowsill  16  also comprises a sufficiently high stability to prevent the head of the vehicle occupant from being catapulted outwards from the vehicle.  
         [0020]    Referring now to FIGS. 2 a  and  2   b  there is illustrated a further advantageous embodiment of the invention whereby like parts already described relative to the first embodiment are identified by like reference numerals. The arrangement and size of the gas bag  114  in accordance with this second embodiment are similar to those in the first embodiment. The gas bag  114  in accordance with the second embodiment consisting of two chambers  116 ,  118 , the first, outer chamber  116  being configured tubular and forming a frame (indicated by circle marks) surrounding the second, cushion-shaped inner chamber  118  (indicated by cross marks).  
         [0021]    The internal pressure in the one chamber  116  differs from that of the other chamber  118 , the outer chamber  116  having a high internal overpressure exceeding 1 bar so that this chamber  116  comprises sufficient stability to serve as a stable frame. The same as in the first embodiment this frame is supported in both the region of the A-pillar  12  and at the windowsill  16 , whereas the second, inner chamber  118  has a significantly lower internal overpressure to prevent the vehicle occupant cushioned by the gas bag from rebounding therefrom. The outer chamber  116  and the inner chamber  118  are not in flow connection with each other. The shape of the transition between the two chambers  116 ,  118  may be made use of to form the rim or kink  24  by which the gas bag  114  is supported at the windowsill  16 .  
         [0022]    It is also conceivable that the inner chamber  118  is further subdivided.