Patent Publication Number: US-2015084315-A1

Title: Vehicle passenger protection system

Description:
RELATED APPLICATIONS 
     This application corresponds to PCT/EP2013/001223, filed Apr. 23, 2013, which claims the benefit of German Application No. 10 2012 008 390.4, filed Apr. 26, 2012, the subject matter of which are incorporated herein by reference in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     The invention relates to a vehicle occupant protection system comprising an airbag. 
     Considerations have been made to arrange an airbag between two vehicle seats so as to prevent collision of the vehicle occupants in the case of a side crash. Such vehicle occupant protection system is described, for example, in DE 10 2009 014 103 A1. The catching distance for such vehicle occupant protection system is short and the airbag must have a relatively large surface so that its deployment is time-critical. Therefore it is of advantage to avoid strong oscillating movements during deployment of the airbag as well as in the deployed state thereof. 
     SUMMARY OF THE INVENTION 
     It is the object of the invention to provide a vehicle occupant protection system in which such airbag adopts its optimum position within short time. 
     In accordance with the invention, for this purpose a vehicle occupant protection system is provided with an airbag which is accommodated in the folded state in a backrest of a vehicle seat and in the deployed state extends between two seats of the vehicle, the airbag having a thorax zone for laterally covering the thorax of a vehicle occupant and a head zone for laterally covering the head of a vehicle occupant, wherein a first fastening portion which is provided directly on an inflator supplying filling gas for the airbag is provided on the airbag, and a second fastening portion which is arranged at the thorax zone between the first fastening portion and an upper end of the backrest is provided on the airbag. 
     The second fastening portion stabilizes the airbag by an additional connecting point fixed on the vehicle, thereby oscillating movements being significantly reduced and the airbag being capable of more quickly adopting its optimum deployed position. 
     The airbag deploys, as known side airbags, out of the backrest of the vehicle seat but is arranged on the side of the backrest facing the neighboring vehicle seat, i.e. not in the seat side facing the vehicle wall or door. 
     The airbag extends substantially in a plane between the vehicle seats and approximately in parallel to a vehicle side wall. The backrest does not comprise the headrest which is considered here to be a separate part connected to the upper end of the backrest. 
     In total, the airbag is configured so that it can also catch a vehicle occupant on a neighboring vehicle seat so as to offer better protection to this vehicle occupant in the case of a side impact. 
     Preferably the second fastening portion is arranged beneath a shoulder of a 95% male dummy. It has turned out that in this way an excellent protective effect can be achieved for both vehicle occupants seated next to each other. 
     The second fastening portion is preferably arranged to be spaced from the upper end of the backrest of the vehicle seat, for example about 10 to 30 cm beneath the upper end of the backrest. 
     The protection by the airbag is ensured for the vehicle occupant on the neighboring vehicle seat (i.e. on the seat on which the airbag is not fastened) both when the vehicle seats are on the same level related to the longitudinal vehicle direction, and when the vehicle seats are offset against each other somewhat in the longitudinal vehicle direction. Also in the event of impact with offset vehicle seats the second fastening portion ensures sufficient stability of the airbag. 
     The second fastening portion can be fastened direction to a frame of the backrest. This is an inexpensive alternative, as no additional components have to be provided. 
     However, it is also possible to fasten the second fastening portion on a fastening component separate from a frame of the backrest, wherein then the fastening component is in turn directly connected to the frame of the backrest. In this variant, different geometries of the airbag and the backrest can be taken into account in a simple manner. 
     It is possible to design the separate fastening component so that also the first fastening portion is directly fixed to the fastening component. It is equally possible to arrange also the inflator directly on the fastening component. 
     In each case, the first fastening portion is preferably fastened via fastening bolts of the inflator on the frame of the backrest so that also in this case no additional components have to be provided. 
     An upper end of the airbag preferably extends at least to an upper end of a headrest, i.e. definitely beyond the upper end of the backrest, and the second fastening portion is arranged approximately in the middle between an upper end of the backrest and the first fastening portion. It has turned out that this geometry permits appropriate stabilization of the airbag in the case of a large surface covered by the airbag. 
     The second fastening portion is an eyelet, for example. 
     The airbag may consist of two cut portions interconnected along a peripheral fastening, wherein the second fastening portion is arranged at the peripheral fastening. 
     It is also possible, as a matter of course, to manufacture the cut portions to be integrally connected on one side and to superimpose them or to manufacture the entire airbag by a one-piece weaving method. 
     The head zone of the airbag preferably has a larger width that the thorax zone, wherein the deployed airbag is especially L-shaped. The wider head zone increases the protection offered by the airbag for the head of the vehicle occupants. 
     It is equally advantageous when the head zone of the airbag completely covers a headrest of the vehicle seat and the head of the vehicle occupant on the vehicle seat. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Hereinafter the invention shall be described in detail by way of two embodiments with respect to the enclosed drawings, in which: 
         FIG. 1  shows a schematic side view of a vehicle occupant protection system according to the invention in accordance with a first embodiment; 
         FIG. 2  shows a schematic side view of a vehicle occupant protection system according to the invention in accordance with a second embodiment; 
         FIG. 3  shows a further schematic view of a vehicle occupant protection system according to the invention; 
         FIG. 4  shows a schematic top view onto a vehicle occupant protection system according to the invention in the case of a purely lateral pole impact with the seating positions being on the same level; 
         FIG. 5  shows a schematic top view onto a vehicle occupant protection system according to the invention in the case of purely lateral pole impact with the seating positions being offset; 
         FIG. 6  shows a schematic top view onto a vehicle occupant protection system according to the invention in the case of an inclined pole impact with the seating positions being on the same level; and 
         FIG. 7  shows a schematic top view onto a vehicle occupant restraint system according to the invention in the case of an inclined pole impact with the seating positions being offset. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
       FIG. 1  illustrates a vehicle occupant protection system  10  comprising a vehicle seat  12  having a seat cushion and a backrest  14  extending upwards. At an upper end  16  of the backrest  14  a separate headrest  18  is arranged. 
     An airbag  20  having the shape of a large inverted L in the deployed and inflated state is fastened to the backrest  14  and before being activated is accommodated in the backrest  14  in a known manner (not shown). 
     The airbag  20  includes two fastening portions  22 ,  24  at which it is connected to the backrest  14 . 
     The first fastening portion  22  is arranged directly at an inflator  26  supplying filling gas for the airbag  20 . For example, it consists of one or two apertures in the airbag  20  through which fastening bolts of the inflator  26  (not shown) are passed. The fastening bolts of the inflator  26  are fastened to a frame  28  of the backrest  14  in the known manner. 
     The second fastening portion  24  is formed by an eyelet at a peripheral fastening  30  of the airbag  20  in this case. 
     The peripheral fastening  30  can be formed, for example, by stitching or interweaving two cut portions  32 ,  34  constituting the airbag  20  (indicated in  FIG. 4 ). 
     The airbag  20  is (theoretically) divided into a thorax zone  36  and a head zone  38  directly connected thereto (cf.  FIG. 3 ). The thorax zone  36  has a width B T  in the longitudinal vehicle direction R (cf.  FIG. 4 ) and approximately perpendicular to the longitudinal extension L of the airbag  20  along the backrest  14  which amounts to approximately half to ⅔ of the width B K  of the head zone  38 . The head zone  38  thus has a definitely larger width B K  than the thorax zone  36  of the airbag  20 . 
     The width B T  of the thorax zone  36  is selected to be so large, however, that the entire thorax of the vehicle occupant  40  seated on the vehicle seat  12  is covered. The width B K  of the head zone  38  is selected to be so large and the head zone  38  of the airbag  20  is arranged so that both the head  42  of the vehicle occupant  40  and the headrest  18  are completely covered on the side. In this way a characteristic inverted L shape is imparted to the airbag  20 . 
     The second fastening portion  24  is arranged at the thorax zone  36  of the airbag  20 . In the embodiment illustrated in  FIG. 1  the second fastening portion  24  is fastened directly on the frame  28  of the backrest  14 , for example by a screw projecting through the eyelet of the fastening portion  24 . 
     The second fastening portion  24  is located somewhat beneath the upper end  16  of the backrest  14 , for example 10 to 30 cm deeper. The second fastening portion  24  thus is arranged somewhat beneath the shoulder of the vehicle occupant  40 , as is evident from  FIGS. 1 to 3 , wherein the vehicle occupant  40  shown here represents a 95% male dummy. 
     In the illustrated example, the second fastening portion  24  is located approximately in the middle between the upper end  16  of the backrest  14  and the first fastening portion  22  level with the inflator  26  and thus somewhat spaced apart from the (theoretical) limit between the head zone  38  and the thorax zone  36  (cf.  FIG. 3 ). 
     The head zone  38  of the airbag  20  extends laterally against the longitudinal vehicle direction R to behind the headrest  18  of the vehicle seat  12 . An upper end  41  of the airbag  20  extends beyond an upper end of the headrest  18 . 
     In the longitudinal vehicle direction R the head zone  38  of the airbag extends to in front of the head  42  of the vehicle occupant  40  on the vehicle seat  12  to which the airbag  20  is fastened (in this case the driver seat). 
     The head zone  38  is so large that the head  44  of the vehicle occupant  40  seated on the vehicle seat  12  is completely covered, just as the headrest  18  of the vehicle seat  12  by the head zone  38  viewed from the side. 
     In the embodiment illustrated in  FIG. 2  the second fastening portion  24  is not directly fastened to the frame  28  of the backrest  14  but to a fastening component  44  separate from the frame  28 . The separate fastening component  44  in this case is an elongate fastening sheet extending from the second fastening portion  24  to the lower end of the inflator  26 . 
     The first fastening portion  22 , too, is connected to the fastening component  44 . 
     For instance, the fastening component  44  includes apertures (not shown) through which the fastening bolts of the inflator  26  are protruding and by which the fastening component  44  is fastened to the frame  28  of the backrest  14 . 
     A second fastening point of the fastening component  44  is preferably predefined by the fixing of the second fastening portion  24  to the frame  28  of the backrest  14 . 
     The airbag  20 , the inflator  26  and the fastening component  44  may constitute a pre-mounted subassembly which is screwed together for mounting the airbag system on the frame  28 . 
     The airbag  20  is arranged on the side of the vehicle seat  12  facing away from a side wall  46  or door of the vehicle. 
     In  FIGS. 4 to 7  the situation for an airbag  20  on a vehicle seat is shown, wherein the airbag  20  has deployed between the vehicle seat  12  and passenger seat  52 . 
     In the case of a side impact (shown here by the situation during a pole test) onto an obstacle  50  located next to the vehicle side wall  46  adjacent to the driver seat  12 , the airbag  20  is intended to absorb a movement of the passenger  48  on the passenger seat  52 . 
       FIG. 4  illustrates a situation in which the vehicle is orientated in the longitudinal vehicle direction R and performs a movement directed perpendicularly to the direction R with respect to the obstacle  50  (arrow B). Perpendicularly to the direction R, the driver seat  12  and the passenger seat  52  are arranged at the same level. 
     In the case of impact onto the obstacle  50 , due to the inertia forces the passenger  48  will perform a movement toward the airbag  20  which has deployed and inflated between the passenger seat  52  and the driver seat  12  (indicated by arrow P). 
     Based on the geometry of the airbag  20 , in this case the passenger  48  strikes the thorax zone  36  and the head zone  38  of the airbag  20  by his/her thorax and head. 
       FIG. 5  illustrates a crash situation in which the vehicle moves equally perpendicularly to the longitudinal vehicle direction R toward the obstacle  50 . In this case, however, the passenger seat  52  is set back somewhat vis-a-vis the driver seat  12  relative to a plane perpendicular to the direction R. 
     In this case, too, the passenger  48  is protected by the airbag  20 . The head of the passenger  48  is absorbed by the head zone  38  of the airbag  20 , especially in the portion which completely covers the headrest  18  of the driver seat  12  laterally and in the height. 
       FIGS. 6 and 7  illustrate a crash situation in the case of an inclined lateral crash in which the longitudinal vehicle direction B of the vehicle relative to the obstacle  50  is inclined relative to the direction of movement R of the vehicle in the longitudinal vehicle direction. 
     In the situation shown in  FIG. 6  the driver seat  12  and the passenger seat  52  are arranged at the same level related to a plane perpendicular to the direction R. 
     Also in this case the passenger  48  is caught by the airbag  20  at the driver seat  12 . As is clearly shown by the arrow P, in each case the passenger  48  impacts on the head zone  38  of the airbag  20 . 
     In the crash situation illustrated in  FIG. 7  the passenger seat  52  and the driver seat  12  are offset against each other related to a plane perpendicular to the longitudinal vehicle direction R, wherein the passenger seat  52  is displaced somewhat backwards again. 
     In this case, too, the passenger  48  is safely caught by the airbag  20 , wherein he/she strikes primarily the thorax zone  36  as well as the entire head zone  38  of the airbag  20 , as is made clear by the arrow P. 
     As is shown by way of the different crash situations, it is sufficient to arrange only one single airbag  20  between the vehicle seats  12 ,  52  so as to be able to safely protect both the driver  40  and the passenger  48 . 
     In the case of crash on the passenger side, the airbag  20  inversely serves as protection for the driver. It is also possible, as a matter of course, to mount the airbag  20  on the passenger seat  52  or to provide a further airbag on the passenger seat  52 . 
     In the vehicle further known airbags can be arranged in the area of the side walls  46 , in the steering wheel and/or an instrument panel apart from the illustrated airbag  20 , as a matter of course.