Abstract:
An occupant protection device with an airbag for fastening in a vehicle seat. In order, in an occupant protection device of this type, to make it possible for the seat to be produced and installed very simply and cost-effectively and to achieve reliable deployment of the airbag, the invention proposes that the occupant protection device has a receiving container for the airbag, which container is free of closure flaps, and the opening of the receiving container is covered by a seat cover of the vehicle seat. In this case, the seat cover is to be fastened to a side wall of the receiving container in such a manner that, when the airbag is inflated with gas, the seat cover tears open in the region of the opening of the receiving container.

Description:
BACKGROUND  
         [0001]    The invention is concerned with an occupant protection device for fastening in a vehicle seat with a receiving container for an airbag.  
           [0002]    An occupant protection device of this type is known, for example, from German patent document no. DE 196 25 436 (incorporated by reference herein). The previously known occupant protection device has a receiving container in which an inflatable airbag is stored. The receiving container is closed by a covering cap. The covering cap has a predetermined breaking point in the form of a groove in its central region. The covering cap breaks open at this predetermined breaking point as soon as the airbag is inflated in the event of a vehicle accident and exerts a corresponding internal pressure on the covering cap. In the previously known occupant protection device, the seat cover is provided with an opening slot in the region of the covering cap of the receiving container. When inflating, the airbag can pass through the seat cover through this slot and can be deployed outside the vehicle seat. The seat cover is fastened in the region of its slot to the covering cap of the receiving container, specifically in such a manner that the two subregions of the seat cover which are separated by the slot are fastened to the covering cap on different sides of the predetermined breaking point. This fastening of the seat cover to the covering cap has the effect that, when the airbag is inflated, the covering cap which breaks open at the predetermined breaking point opens the slot of the seat cover and allows the airbag “to pass”.  
           [0003]    Another occupant protection device is described in German utility model DE 299 12 825 (incorporated by reference herein). In this previously known occupant protection device, a receiving container for an airbag is likewise provided. The receiving container has a covering part which can swing open and which covers the receiving container. The covering part is swung open by means of pulling means as soon as the airbag is inflated. In order to make it possible for the covering part to swing open, a hinge section is provided about which the covering part is pivoted when appropriately actuated by the pulling means.  
           [0004]    A further occupant protection device is described in German utility model DE 296 01 257 (incorporated by reference herein). This previously known occupant protection device has a receiving container which receives an airbag and is closed by a covering cap. The covering cap is mounted in a manner such that it can rotate about a pivot axis and has tearing teeth on its outer side, which faces the seat cover. If the airbag is inflated, then, the airbag presses from the inside against the covering cap and pivots the cap outwards, as a result of which the tearing teeth of the covering cap tear open the seat cover and provide an opening for the airbag.  
         SUMMARY OF THE INVENTION  
         [0005]    The invention is based in part on the object of specifying an occupant protection device which can be produced and installed simply and cost-effectively and ensures reliable deployment of the airbag of the occupant protection device.  
           [0006]    Accordingly, provision is made according to the invention for the receiving container for the airbag to be designed in a manner free of closure flaps. Unlike in the above-described, previously known occupant protection devices, this measure enables a component to be left out, as a result of which the production costs are reduced. In the occupant protection device according to the invention, instead of a covering cap the seat cover, which is present in any case, of the vehicle seat is used for covering the “open” receiving container. In order to ensure that the airbag can be deployed correctly, the seat cover has to tear open during inflation of the airbag. This is achieved according to the invention by the seat cover being fastened to a side wall of the receiving container. According to the invention, the effect achieved by the lateral fastening of the seat cover is that, when the airbag is inflated, the seat cover cannot “give way” or “yield” but has to tear open virtually immediately on account of the pressure of the airbag. The tearing-open of the seat cover then creates an opening in the seat cover through which the airbag can pass. An “active” element having tearing teeth for tearing open the seat cover—as is provided in the above-described occupant protection device according to German utility model DE 296 01 257—is therefore not required in the occupant protection device according to the invention.  
           [0007]    According to one advantageous refinement of the occupant protection device according to the invention, provision is made for the seat cover to have a predetermined breaking point in the region of the opening of the receiving container. This is because this predetermined breaking point facilitates the tearing-open of the seat cover by the airbag which is being deployed.  
           [0008]    Then, in an advantageous manner, the seat cover should be fastened to the side wall in the region of the predetermined breaking point. The effect achieved by this is namely that even a slight pressure or counterpressure of the airbag is sufficient in order to tear open the seat cover.  
           [0009]    A predetermined breaking point of this type can be formed in a particularly simple and therefore advantageous manner by means of a seam which closes a slot in the seat cover.  
           [0010]    It is advantageous if the seat cover is folded over into the seat interior in the region of the slot forming two adjacent hems, and the adjacent edge regions of the two hems are sewn together. The connection between the seat cover and the side wall of the receiving container can then be produced in a very simple and therefore advantageous manner by at least one of the two hems of the seat cover being connected to the side wall.  
           [0011]    Moreover, it is regarded as advantageous if the receiving container is attached at the top of the vehicle seat, specifically with its opening facing the upper end of the backrest of the vehicle seat. The airbag can then be deployed between the head restraint and the vehicle occupant&#39;s head.  
           [0012]    In order to ensure a particularly rapid tearing-open of the seat cover, it is regarded as advantageous if the seat cover is attached to that side wall of the receiving container which faces the vehicle occupant.  
           [0013]    In a particularly simple and therefore advantageous manner, the seat cover can be fastened to the side wall with a plastic strip by the one side of the strip being connected to the seat cover and the other side of the strip being connected to the side wall. In an advantageous manner, the one strip side can be sewn to the seat cover and/or the other strip side can be hooked in on the side wall.  
           [0014]    According to a further refinement of the occupant protection device according to the invention, provision is made for the fastening of the seat cover to the side wall to be brought about by at least two hooks which are attached to the side wall and are hooked into holes in the hem of the seat cover. In this further refinement of the occupant protection device, the fastening of the seat cover to the side wall is therefore brought about without a strip.  
           [0015]    According to a third advantageous refinement of the occupant protection device according to the invention, provision is made for the fastening of the seat cover to the side wall to be brought about by a snap-in strip into which snap-in hooks fastened to the seat cover snap. A substantial advantage of this third refinement of the occupant protection device can be seen in the fact that the connection between the seat cover and the side wall can be effected in a very simple manner owing to the snap-in strip, since, after installation of the receiving container in the vehicle seat, the snap-in hooks which are fastened to the seat cover have merely to be latched or “snapped” into the snap-in strip.  
           [0016]    In this third advantageous refinement of the occupant protection device according to the invention, the snap-in strip can advantageously be fastened directly to the side wall. Instead of this, it may also be fastened to the side wall via further snap-in hooks.  
           [0017]    As already discussed above, the seat cover can be connected to the side wall in the region of the predetermined breaking point; instead of this or in addition, the seat cover may also be fastened in the lower region of the side wall, specifically to that side wall of the receiving container which faces the vehicle occupant.  
           [0018]    In order to increase the comfort of the vehicle seat for the vehicle occupant, it is regarded as advantageous if a seat cushion is provided between the seat cover and the receiving container. In the region of the opening of the receiving container there should then be at least one predetermined breaking point in the seat cushion, in order to facilitate a tearing-open of the seat cover and seat cushion during inflation of the airbag.  
           [0019]    The predetermined breaking point can be provided in a particularly simple manner and therefore in a particularly advantageous manner by at least one hole being provided in the seat cushion, the said hole lying in the region of the opening of the receiving container.  
           [0020]    The occupant protection device according to the invention is preferably a “roll-over module” for protecting the head of the occupant in the case of a roll-over of the vehicle. Instead, the occupant protection device according to the invention may also be used as a side-protection module.  
           [0021]    It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only, and are not restrictive of the invention as claimed. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0022]    These and other features, aspects and advantages of the present invention will become apparent from the following description, appended claims, and the accompanying exemplary embodiments shown in the drawings, which are briefly described below.  
         [0023]    [0023]FIGS. 1 a  and  1   b  are illustrations of how an airbag would be deployed in an occupant protection device in which the seat cover is not fastened to a side wall of a receiving container,  
         [0024]    [0024]FIGS. 2 a,    2   b,    2   c  are illustrations of how an airbag is deployed in an occupant protection device according to the invention in which a fastening of the seat cover is provided,  
         [0025]    [0025]FIG. 3 shows an exemplary embodiment for an occupant protection device according to the invention, in which the seat cover is fastened in the upper region of the side wall of the receiving container,  
         [0026]    [0026]FIG. 4 shows an exemplary embodiment for an occupant protection device according to the invention, in which the seat cover is fastened in the lower region of the side wall of the receiving container,  
         [0027]    [0027]FIG. 5, 5 a  shows two exemplary embodiments for an occupant protection device according to the invention with a plastic strip for hooking the seat cover in on a side wall of the receiving container,  
         [0028]    [0028]FIG. 6 shows an exemplary embodiment for an occupant protection device according to the invention, in which hooks on the side wall of the receiving container serve for the “attachment” of the seat cover,  
         [0029]    [0029]FIGS. 7 a  and  7   b  show an exemplary embodiment of the occupant protection device according to the invention, in which a snap-in strip which is integrated in the seat cushion is provided,  
         [0030]    [0030]FIG. 8 shows an exemplary embodiment for an occupant protection device according to the invention, in which hooks of a plastic rail, which is fastened to the seat cover, are latched in on the side wall of the receiving container. 
     
    
     DETAILED DESCRIPTION  
       [0031]    [0031]FIGS. 1 a  and  1   b  show how an airbag would be deployed in an occupant protection device, in which the seat cover is not fastened to a side wall of the receiving container of the airbag. Specifically, FIGS. 1 a  and  1   b  show a vehicle seat  10  which has a backrest frame  20 , a seat cushion  30  and a seat cover  40 . An occupant protection device  50  which has an airbag module  60  is provided in the vehicle seat  10 . The airbag module  60  includes an upwardly open receiving container  70  which is bounded laterally by side walls  80 . A filling pipe  90  having a gas generator (not illustrated specifically) is connected to the bottom of the receiving container  70 . An airbag  100  which is contained in the receiving container  70  is inflated by the gas generator and the filling pipe  90  and the event of a vehicle accident.  
         [0032]    The inflation process will now be described in greater detail with reference to the two FIGS. 1 a  and  1   b.  In FIG. 1 a,  it can be seen that the airbag  100  is still empty of air and is situated entirely in the receiving container  70  of the airbag module  60 . If the airbag  100  is then inflated by the gas generator and the filling pipe  90 , it has to be deployed in the direction of the opening  110  of the receiving container  70 , since a lateral expansion is not possible on account of the side walls  80 . This expansion is illustrated in FIG. 1 a  by means of arrows  120 .  
         [0033]    [0033]FIG. 1 b  shows how the airbag  100  has partially left the receiving container  70 . The seat cushion  30  is pushed apart above the opening  110  of the receiving container  70  by the airbag  100 ; however, a predetermined breaking point  150  in the seat cover  40  above the opening  110  of the receiving container  70  has not yet been torn open. This is specifically because the seat cover  40  is slightly elastic and so a “migration” of the seat cover occurs. This is illustrated in FIG. 1 b  by means of arrows  160 . This stretching of the seat cover  40  enables the airbag  1   00  to be at least partially deployed within the vehicle seat  10 , which prevents a defined tearing-open of the predetermined breaking point  150  which can be formed, for example, by a tearing seam.  
         [0034]    It is explained in FIGS. 2 a  and  2   b,  with reference to an exemplary embodiment of the occupant protection device according to the invention, how the “bulging” of the seat cover  40  due to the airbag  100  can be avoided. In FIGS. 2 a  and  2   b  and in the other figures explained further below, identical reference numbers are used for identical elements of the occupant protection device.  
         [0035]    [0035]FIGS. 2 a  and  2   b  show, in turn, a vehicle seat  10  with a backrest frame  20 , a seat cushion  30  and a seat cover  40 . An occupant protection device  50  having an airbag module  60  is integrated in the vehicle seat  10 . The airbag module  60  has a receiving container  70  for an airbag  100  which can be filled with gas by means of a gas generator and a filling pipe  90 .  
         [0036]    In contrast to the occupant protection device according to FIGS. 1 a  and  1   b,  in the exemplary embodiment according to FIGS. 2 a  and  2   b,  the seat cover  40  is fastened to the side wall  80  of the receiving container  70 . FIGS. 2 a  and  2   b  therefore show a fastening element  200  which is fastened by its one end  210  to the seat cover  40  and by its other end  220  to the side wall  80  of the receiving container  70 .  
         [0037]    If the airbag  100  is now inflated, the airbag  100  is deployed again above the receiving container  70  and exerts a pressure against the seat cover  40 . This pressure causes the predetermined breaking point  150  to tear. In contrast to the occupant protection device according to FIGS. 1 a  and  1   b,  bulging of the seat cover  40  cannot occur because the seat cover  40  is namely fixed to the side wall  80  of the receiving container  70  in the region of the opening  110  of the receiving container  70 . This fixing reliably prevents a “migration” of the seat cover  40  or a “bulging” of the seat cover  40 . The expanding airbag  100  must therefore inevitably tear open the predetermined breaking point  150  and thus create an opening “to the outside”.  
         [0038]    Since the migration or bulging of the seat cover  40  is reliably avoided in the occupant protection device according to FIGS. 2 a  and  2   b,  a very rapid opening of the airbag  100  is ensured.  
         [0039]    [0039]FIG. 2 c  shows an alternative embodiment wherein the seat cover  40  is fixed to the receiving container  70  in a different manner using two fastening elements  200  and  200 ′.  
         [0040]    [0040]FIG. 3 shows the occupant protection device according to the invention from FIGS. 2 a  and  2   b  once again in a different illustration. The vehicle seat  10  with the seat cushion  30 , the seat cover  40  and the backrest frame  20  can be seen. The occupant protection device  50  is integrated in the vehicle seat  10 . Moreover, a head restraint  250  which is fastened to the top of the vehicle seat  10  can be seen in FIG. 3.  
         [0041]    [0041]FIG. 4 illustrates an exemplary embodiment for an occupant protection device according to the invention, in which the seat cover  40  is fastened in the lower region of the side wall  80  of the receiving container  70 . FIG. 4 specifically shows that the fastening means  200  is fastened to that region of the side wall  80  which is adjacent to the filling pipe  90 . A tearing seam  150  is provided above the opening  110  of the receiving container  70  as the predetermined breaking point.  
         [0042]    [0042]FIG. 5 shows an exemplary embodiment for an occupant protection device according to the invention, in which a plastic strip  400  is provided for fastening the seat cover  40  to the side wall  80  of the receiving container  70 . In the occupant protection device according to FIG. 5, the side wall  80  is bent in its upper region in such a manner that the plastic strip  400  can be attached into the side wall  80 . In order to fasten the plastic strip  400 , the strip is sewn on its one strip side  410  to a hem  420  of the seat cover  40 . In this case, the hem  420  is formed by the seat cover  40  being folded over twice into the seat interior in the region of the tearing seam  150 . The one hem  420  and a second hem  430  are produced by this folding-over process. The edge regions  440  and  450  of the two hems are adjacent to each other and are sewn to each other by the tearing seam  150 .  
         [0043]    The other strip side  460  of the plastic strip  400  is of bent design and can therefore be hooked into the likewise bent, upper region  470  of the side wall  80 . For this purpose, the other strip side  460  has a “mating shape” to the upper region  470  of the side wall  80 .  
         [0044]    According to FIG. 5, only the hem  420  is fixed to the side wall  80 . In the same manner, the second hem  430  may also be fixed to the side wall  80 . For instance, both hems  420  and  430  may be fixed to the side wall  80  (see FIG. 5 a ). In the latter case, the hem  420  is preferably fixed to the front part (in driving direction) of the side wall and the second hem  430  is connected to the rear part (in driving direction) of the side wall.  
         [0045]    [0045]FIG. 6 shows an exemplary embodiment for an occupant protection device according to the invention, in which hooks  500  are provided on the side wall  80  of the receiving container  70 .  
         [0046]    The hem  420  of the seat cover  40  has holes  510 , the distances of which from one another correspond to the distance between the hooks  500 .  
         [0047]    In order to fasten the seat cover  40  to the side wall  80  of the receiving container  70 , the holes  510  of the hem  420  are hooked into the hooks  500  of the side wall  80 , thus resulting in fastening of the hem  420 .  
         [0048]    It can moreover be seen in FIG. 6 that the hem  420  and the further hem  430  of the seat cover  40  are sewn to each other by the tearing seam  150 .  
         [0049]    According to FIG. 6, only the hem  420  is fixed to the side wall  80 . In the same manner, the second hem  430  may also be fixed to the side wall  80 .  
         [0050]    [0050]FIGS. 7 a  and  7   b  show an exemplary embodiment for an occupant protection device, in which the fixing of the seat cover  40  takes place in the lower region of the receiving container  70 , as has already been explained further above in conjunction with FIG. 4.  
         [0051]    In the exemplary embodiment according to FIGS. 7 a  and  7   b,  a snap-in strip  600  is provided to which snap-in hooks  610  and further snap-in hooks  620  are fastened. The snap-in hooks  610  are sewn firmly to the seat cover  40 , for example by means of seams  630 . The further snap-in hooks  620  are fastened directly to the side wall  80  of the receiving container  70 .  
         [0052]    It can moreover be seen in FIGS. 7 a  and  7   b  that the snap-in strip  600  is incorporated—for example foamed—into the seat cushion  30 . In other words, the snap-in strip  600  is thus part of the seat cushion  30 , on which the snap-in hooks  610  of the seat cover  40  are latched on the one side and the further snap-in hooks  620  of the side wall  80  are latched on the other side.  
         [0053]    [0053]FIG. 8 shows an exemplary embodiment for the occupant protection device according to the invention, in which a plastic rail  700  is sewn on at the one hem  420  of the seat cover  40 . A hook  710 —or a plurality of hooks  710 —is/are fastened to the plastic rail  700 ; each of these hooks  710  is guided in each case through a hole  720  in the seat cushion  30 .  
         [0054]    The holes  720  serve, on the one hand, to ensure the connection of the hook  710  or of the hooks  710  to the side wall  80  of the receiving container  70 ; on the other hand, they also serve to form a predetermined breaking point in the seat cushion  30 . This is because if the airbag  100  is to be deployed, then in addition to the tearing seam  150  the seat cushion  30  also has to be opened. Such an opening or “breaking open” or “tearing open” of the seat cushion  30  is significantly facilitated by the holes  720  in the seat cushion  30 .  
         [0055]    As an alternative, the holes  720  in the seat cushion  30  may also be replaced by a gap in the seat cushion  30 , through which the hooks  710  of the plastic rail  700  are then guided to the side wall  80  of the receiving container  70 . In contrast to such a gap, the holes  720  have the advantage that the upper region of the seat cushion  30  is overall more stable, as a result of which the seat cover  40  fits more snugly against the seat cushion  30  and, in particular, a wavy formation of the seat cover  40  on the seat cushion  30  is avoided.  
         [0056]    [0056]FIG. 8 furthermore shows fastening elements  750  which are used to fasten the receiving container  70  and therefore the airbag module  60  to the backrest frame  20  of the vehicle seat  10 .  
         [0057]    The priority application DE 102 44 866.3-42 filed on Sep. 23, 2002 is hereby incorporated by reference herein in its entirety.  
         [0058]    Given the disclosure of the present invention, one versed in the art would appreciate that there may be other embodiments and modifications within the scope and spirit of the invention. Accordingly, all modifications attainable by one versed in the art from the present disclosure within the scope and spirit of the present invention are to be included as further embodiments of the present invention. The scope of the present invention is to be defined as set forth in the following claims.