Abstract:
An airbag arrangement for a vehicle occupant restraint system is provided. The airbag arrangement comprising an inflatable airbag for protecting a vehicle occupant, a fastening element for fastening the airbag to a support structure, and means for counteracting a torquing of the fastening element pre-mounted at the airbag, wherein the means comprise an opening through which the pre-mounted fastening element reaches, said opening being designed to counteract a torquing of the pre-mounted fastening element. The opening comprises two sections that cross one another.

Description:
CROSS-REFERENCE TO A RELATED APPLICATION 
       [0001]    This application is a continuation of International Application PCT/EP2009/058591, filed on Jul. 7, 2009, which claims priority of German Patent Application Number 10 2008 032 964.9, filed on Jul. 9, 2008, including the specification, drawings, claims and abstract, is incorporated herein by reference in its entirety. 
     
    
     BACKGROUND 
       [0002]    The invention relates to an airbag arrangement for a vehicle occupant restraint system. 
         [0003]    An airbag arrangement, which is mounted to a body structure of a vehicle by the means of a fastening clip, is for instance known from DE 20 2006 000 846 U1. 
       SUMMARY 
       [0004]    The object to be solved by the invention is to provide an airbag arrangement which can be assembled in a simple manner. 
         [0005]    According to an exemplary embodiment of the invention an airbag arrangement for a vehicle occupant restraint system is being provided comprising:
       an inflatable airbag for protecting a vehicle occupant,   a fastening element for fastening the airbag to a support structure, and   means for counteracting a torquing of the fastening element pre-mounted at the airbag, whereby   the means comprise an opening through which the pre-mounted fastening element reaches and is being designed for counteracting a torquing of the pre-mounted fastening element.       
 
         [0010]    The opening comprises furthermore two sections that cross one another. 
         [0011]    The support structure can be in particular a part of a vehicle body or a part connected to the vehicle body, which comprises a fastening opening in which the fastening element can be locked. By the means of the fastening elements locked to a support structure the airbag is arranged on the support structure. 
         [0012]    The opening with the sections crossing each other provides that the fastening element during its pre-mounting with the airbag can already be brought into the correct mounting position and remains in said position. A new aligning (rotating) of the fastening element immediately before the mounting of the airbag at the vehicle body is omitted. 
         [0013]    In an example the sections of the opening crossing each other are formed longitudinal (for instance slid-like) and continue for instance approximately vertical to each other. In particular, the sections cross each other with their respective middle sections so that a symmetrical cross-like opening is formed, for instance in form of a “Swiss Cross”. A symmetrical design of the opening is however not necessarily required. 
         [0014]    A fastening element can be used which comprises two arms opposing each other via which the fastening element can be locked to the support structure. Such a fastening element is for instance described in the German utility model DE 20 2004 014 219 which is in so far referenced herewith. One of the sections of the opening crossing each other is in particular formed such that the arms of the fastening element can reach trough said section without being compressed together. 
         [0015]    In another example the opening through which the fastening element is supposed to reach in its mounting position is formed in a fastening strap via which the airbag can be mounted at the support structure. The fastening strap sticks out from the airbag and can be connected with it by connecting means (for instance a stitching). It is however also possible that the fastening strap is integrally formed with the airbag. 
         [0016]    The fastening strap can in particular comprise multiple material layers (for instance from an airbag material), whereby the opening for the fastening means which serves as torquing protection, is formed for instance only in one of the material layers or also in multiple of the material layers. However, in each of the material layers an opening has to be present, which does not serve necessarily as torquing protection, through which however the fastening element can be guided. 
         [0017]    In a further exemplary variant of the invention the opening for torquing protection is formed in a part different from the fastening strap, whereby the part is connected to the fastening strap. This part can be for instance arranged on a side of the fastening strap, which faces away from the support structure in the mounted status of the airbag. It is however not necessarily required that the opening for the torquing protection is arranged in a part separate from the fastening strap. In another variant of the invention the fastening strap itself comprises the opening with the sections crossing each other. 
         [0018]    Furthermore, the fastening strap can comprise a first section and a second section, whereby the second section is folded in direction of the first section that means the first section is connected to the second section via a bend. The ends of the sections distanced from the bend are in particular arranged at the airbag. The opening with the sections crossing each other is formed in this variant for instance in one of the two sections of the fastening strap. 
         [0019]    In a further exemplary improvement of this variant the second section of the fastening element comprises an opening, which counteracts a torquing of the pre-mounted fastening element (that means the opening with the sections crossing each other), while the first section comprises an opening, which aligns with the opening in the second sections, is however not designed and provided for counteracting a torquing of the pre-mounted fastening element. 
         [0020]    Therefore, only one of the openings in the fastening strap serves as a torquing protection, that means is formed such that the fastening element through which said strap reaches after pre-mounting at the airbag cannot or only slightly be torqued. The opening formed in the first section however has another design than the opening in the second section so that said opening does not counteract a torquing of the fastening element. The opening in the first section of the fastening strap is for instance formed circular. Since only one of the opening serves as a torquing protection the guiding of the fastening element through the fastening strap during the pre-mounting is simplified. 
         [0021]    The second section in which the opening for the torquing protection is formed is in particular the section of the fastening strap which faces away from the support structure in the mounted status of the airbag. 
         [0022]    Furthermore, the fastening element in the mounted status can rest against one side of the fastening strap with a sub-section, which faces away from the support structure. The second section of the fastening strap is thereby designed such that the sub-section of the fastening element rests only against the first section of the fastening strap. More precise, the sub-section of the fastening element rests against a side of the first section, which faces away from the support structure in the mounted status of the airbag. 
         [0023]    The sub-section which rests against the fastening strap is formed in particular by two contact surfaces of the fastening element distanced from each other. The width in the area of the opening of the second section of the fastening strap is in particular selected such that it is smaller that the distance of the two contact surfaces in the mounted status of the fastening element. Therefore, the contact surfaces of the fastening element rest only against the first section of the fastening strap. 
         [0024]    In a further aspect the invention relates to an airbag arrangement, in particular as described further above in respect to the opening for torquing protection with sections crossing each other, comprising:
       an inflatable airbag for protecting a vehicle occupant,   a fastening strap connected to the airbag via which the airbag can be fastened to a support structure, whereby   a first opening formed in the fastening strap,   a fastening element for fastening the airbag to the support structure which reaches through the first opening in the mounted status of the airbag, and   means for counteracting a torquing of the fastening element pre-mounted to the airbag, whereby   the means comprise a second opening (opening for a torquing protection) in a portion (torquing protection) different from the fastening strap, through which the pre-mounted fastening element reaches and is being formed for counteracting a torquing of the pre-mounted fastening element.       
 
         [0031]    Furthermore, the part with the second opening can be clamped to the fastening strap, for which reason it is designed clamp-like. 
         [0032]    Therewith the part which serves as a torquing protection for the pre-mounted fastening element is connected to the fastening strap in a detachable manner. The fastening strap connected to the airbag comprises for instance one or multiple layers, whereby the part with the opening for torquing protection can be connected to one of the layers or also with all layers via a clamp connection. This is done in particular such that the first and the second opening align with each other. 
         [0033]    The clamp-like portion comprises in particular a first section and a second section, whereby the second section is bent in direction of the first section. The part is therefore formed in one piece which is being bent along a bending line so that it receives its clamp-like shape and comprises two sections opposing each other, which are connected with each other via a bend. A restoring force is created by bending apart these sections, which is used for clamping the part on the fastening strap. 
         [0034]    The first as well as the second section of the part comprise an opening, which together form the second opening. However, it is sufficient if one of the two openings is formed as a torquing protection. 
         [0035]    The part can be clamped onto the fastening strap such that the first section of the part rests against a side of the fastening strap, which is to face the support structure, while the second section of the part rests against a side of the fastening strap, which in the mounted status of the airbag faces away from the support structure. The opening for a torquing protection is for instance formed in the second section of the part, which in the mounted status of the airbag faces away from the support structure. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0036]    The invention is explained in the following in more detail by the means of examples referring to the Figures. 
           [0037]      FIG. 1  shows a perspective illustration of components of an airbag arrangement according to a first embodiment of the invention. 
           [0038]      FIG. 2  shows the airbag arrangement of  FIG. 1  in the assembled status. 
           [0039]      FIG. 3  shows a sectional view of the airbag arrangement from the  FIGS. 1 and 2 . 
           [0040]      FIG. 4  shows a further sectional view of the airbag arrangement of the airbag arrangement from the  FIGS. 1 to 3 . 
           [0041]      FIG. 5  shows an airbag arrangement according to a second embodiment of the invention. 
           [0042]      FIG. 6  shows an airbag arrangement according to a third embodiment of the invention. 
           [0043]      FIG. 7  shows a perspective illustration of components of an airbag arrangement according to a fourth embodiment of the invention. 
           [0044]      FIG. 8  shows the airbag arrangement of  FIG. 7  in the assembled status. 
       
    
    
     DETAILED DESCRIPTION 
       [0045]      FIG. 1  relates to a first embodiment of the invention according to which an airbag  1  comprises a first fastening strap  2  via which said airbag can be fastened to a holding structure (not shown), for instance a part of a vehicle body. 
         [0046]    The fastening strap  2  comprises a first section  21  as well as a second section  22  which is folded (or bent) in direction of the first section  21 , whereby ends  212 ,  213  of the respective sections  21 ,  22  are supposed to be connected to the airbag  1 . The sections  21 ,  22  are connected with each other via a bend  24  of the fastening strap  2 . Furthermore, the first and the second section  21 ,  22  comprise in each case a through opening  211 ,  221 , which are aligned with each other. 
         [0047]    The through openings  211 ,  221  serve the purpose to be able to guide a fastening element  3  through the fastening strap  2 , which can lock to the holding structure and therefore can arrange the airbag  1  at the holding structure. The fastening element  3  is pre-mounted to the airbag before the actual mounting of the airbag  1  to the holding structure, that means it is guided through the opening  41  of the portion  4  and the openings  211 ,  221  of the fastening strap  2  and is aligned such that it can be locked in a fastening opening (not shown) of the holding structure. 
         [0048]    The airbag arrangement comprises means for preventing a torquing of the pre-mounted fastening element  3 , which comprise an opening  41  in a part  4 . 
         [0049]    The opening  41  of the part  4  is formed such that it counteracts a torquing of the such pre-mounted fastening element  3 . For this reason, the opening  41  comprises two sections  411 ,  412  crossing each other, that means the opening is in form of a cross. 
         [0050]    The fastening element  3  comprises two arms  31   a ,  31   b  opposing each other, which while inserting the fastening element into the fastening opening of the holding structure bend towards each other and lock to the holding structure by the means of a locking structure  32   a ,  32   b , respectively. 
         [0051]    One of the sections crossing each other (the “horizontal” section  412 ) is made such, that means it has an appropriate length and height, that the arms  31   a ,  31   b  of the fastening element  3  can reach through the section  412  and therefore through the opening  41  so that the section  412  blocks a torquing of the arms  31   a ,  31   b  and therefore the complete fastening element  4 . The section  412  is in particular formed such that the arms of the fastening element can be guided through said section without being pressed together or without being strongly pressed together so that the torquing protection can be optimal effective through the section  412 . 
         [0052]    The fastening element  3  comprises furthermore two further arms  33   a ,  33   b  also opposing each other on which the respective contact surfaces  34   a ,  34   b  are formed, which in the assembled status of the airbag rests against the fastening strap  2  and which press said strap after locking the fastening element  3  to the holding structure against the holding structure. 
         [0053]    The section  411  of the opening  41  aligned vertically to the section  412  is formed such that the arms  33   a ,  33   b  of the fastening element  3  can be guided through, in particular such that they are while guiding through the opening  4  are not or only slightly pressed together. 
         [0054]      FIG. 2  shows the arrangement from  FIG. 1  in the assembled status. The ends  212 ,  213  of the two sections  21 ,  22  of the fastening strap  2  are connected to the airbag  1  via a stitch  11 . Simultaneously, also the part  4  (the torque protection) is fastened via the stitch  11  to the fastening strap  2 . The part  4  is formed in stripes and has a width B, which is smaller than the distance of the respective contact surfaces  34   a ,  34   b  of the arms  33   a ,  33   b  so that the contact surfaces  34   a ,  34   b  rest not on the part  4 , but only on one side of the fastening strap  2 , which in the assembled status of the airbag faces away from the holding structure. 
         [0055]      FIG. 3  shows a vertical cross section of the arrangement of  FIG. 2 . Due to the folded (or bent) design of the fastening strap  2  the fastening strap  2  creates while inserting the fastening element  3  into the openings  41 ,  211  and  221   a  restoring force F so that the part  4  is pressed against the fastening element  3 . Through this, the opening  41  is positioned in an area of the fastening element  3  in which the arms  31   a ,  31   b  and  33   a ,  33   b  have approximately the largest possible distance to each other. 
         [0056]      FIG. 4  shows the airbag arrangement from the  FIGS. 1 to 3  in a cross section which is vertical to the cross section of  FIG. 3 . It is in particular recognizable that the locking structures  32   a ,  32   b  of the fastening element  3  reach in each case with a section  321   a ,  321   b  behind the holding structure (not shown) to which the airbag  1  is supposed to be fastened, and can therefore lock to the holding structure. 
         [0057]      FIG. 5  is a perspective illustration of an airbag arrangement according to a second embodiment of the invention. An airbag  1  has a fastening strap  2  connected to said airbag, which comprises as in the  FIGS. 1 to 4  a first and a second section  21 ,  22 , which are folded towards each other opposing each other. 
         [0058]    However, different to the  FIGS. 1 to 4  no specific part is present in which an opening for preventing a torquing of the pre-mounted fastening element is arranged. Instead, in the second section  22  of the fastening strap  2 , which in the assembled status of the airbag faces away from the holding structure, a cross-like opening  41  is formed, which prevents a torquing of the pre-mounted fastening element  3  being guided through said opening. Herewith, the second section  22  of the fastening strap fulfils the function of the separate parts  4  of the  FIGS. 1 to 4 . 
         [0059]    The first section  21  of the fastening strap  2  has an opening  211  aligned with the opening  41 , which is formed circular and has therefore a different shape than the cross-like opening  41 . It is however possible that the opening  211  in the first section  21  is also formed cross-like. 
         [0060]    An area  215  of the second section  21  (in the height of the opening  41 ) has a smaller width than an end section  213  of the second section  22  which is arranged to the airbag  1 . The width B of the section  215  is in particular selected such that the contact surfaces  34   a ,  34   b  of the fastening element  3  do not rest on the second section  22  of the fastening strap  2 , but rather only on the first section  21 , which is to face the holding structure. A modification of the  FIG. 4  is shown in  FIG. 6 , whereupon the width B of the second section  22  of the fastening strap  2  is almost constant over the complete length of the second section  22 , that means the second section  22  has in the area of the opening  41  the same width as the end section  213  via which the fastening strap  2  is arranged on the airbag  1 . 
         [0061]    The  FIGS. 7 and 8  relate to a further variant of an airbag arrangement according to the invention. Similar to the  FIGS. 1 to 4  a part  4  being different from the fastening strap  2  is present, which comprises an opening  41 , which is formed such that said opening serves as torquing protection for the fastening element  3 . The opening  41  is in particular formed cross-like in analogy to the  FIGS. 1 to 6 . 
         [0062]    However, different to the  FIGS. 1 to 4  the separate part  4  is formed clamp-like so that it can be clamped to the fastening strap  2  in a detachable manner. This means that part  4  is not connected to the fastening strap in a lasting manner, but rather is being attached to the fastening strap whereby after attaching the part  4  the opening  41  in the part  4  and the openings  211 ,  221  in the fastening strap  2  align with each other. 
         [0063]    The part  4  is in particular formed in one piece which comprises a first section  45  and a second section  46  which is bent in direction of the first section  45  such that the sections  45 ,  46  are connected with each other via a bend  47 . The part  4  is made such (for instance due to the fact that it is made of a suitable material like metal or plastic) that by bending the sections  45 ,  46  towards each other a clamp is formed, which creates by bending away from each other (that means exerting a force F) a restoring force such that the part  4  can be clamped on the fastening strap  2 . 
         [0064]    The first section  45  has an opening  451  which aligns with the opening  41  for torquing protection and can have a similar or identical shape. It is however also possible that the opening  451  is designed differently in the section  45 , for instance circular. 
         [0065]    In this embodiment the two openings  211 ,  21  in the fastening strap  2  form a first opening and the openings  451  and  42  in the part  4  form a second opening. After clamping the part  4  on the fastening strap the first and the second opening are aligned with each other. 
         [0066]      FIG. 8  shows the components of  FIG. 7  in assembled status.