Abstract:
An airbag of an occupant protection device includes at least two overlapping airbag panels, a front fabric panel connected to a rear fabric panel. A chamber is formed between the front and back panels. A gusset is positioned to allow the front and rear panels to separate at a point where the front and rear panels are connected by the gusset. The airbag has high inflating thickness and nearly proportional increase in gas volume for inflation of the airbag.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS  
       [0001]     This application claims priority to and the benefit of the following U.S. Provisional Patent Applications: 
        application Ser. No. 60/627,025, filed Nov. 12, 2004;     application Ser. No. 60/627,178, filed Nov. 15, 2004;     application Ser. No. 60/628,539, filed Nov. 18, 2004;     application Ser. No. 60/652,731, filed Feb. 15, 2005; and     application Ser. No. 60/646,487, filed Jan. 25, 2005. 
 
 Each of the foregoing applications are incorporated by reference herein.
       
 
     
    
     BACKGROUND  
       [0007]     The present invention relates to an airbag of an occupant protection device.  
         [0008]     As is generally known in the art, an airbag for protecting the head of a vehicle occupant is installed adjacent to a corner of a vehicle interior where a roof panel and a side panel are joined to each other, and is constructed so as to be deployed along a side door window and the like when gas is introduced therein from an inflator through a gas inlet.  
         [0009]     International Publication No. WO 97/06987 (hereby incorporated by reference herein in its entirety) discloses a side airbag which is deployed on the side of a vehicle occupant. In the side airbag, a longitudinal intermediate portion of a bag is constricted by a seam which extends in a transverse direction (a lengthwise direction of a vehicle body: this also applies to the following description), so that the bag is divided into an upper portion and a lower portion. A panel is positioned along a portion of the airbag which faces the vehicle occupant. The upper and lower portions of the panel are respectively connected to the upper and lower portions of the bag. When the bag is inflated, the panel is tightly stretched. Then, as the shoulder of the occupant comes into contact with the bag, the panel pulls the upper portion of the bag downward. As such, the upper portion of the bag is pulled toward the vehicle occupant to protect the head of the vehicle occupant.  
         [0010]     Japanese Unexamined Patent Application Publication No. 2003-72500 discloses an airbag for protecting the head of a vehicle occupant (hereby incorporated by reference herein in its entirety). In this type of airbag, supporting fabric is positioned on the sides of a bag which faces both a vehicle occupant and a vehicle body. The upper and lower edges of the supporting fabric are coupled to the upper and lower edges of the bag.  
         [0011]     In the case where the airbag disclosed in International Publication No. WO 97/06987, which has the panel positioned so as to face the vehicle occupant, is employed as a head protection airbag, when the head of the vehicle occupant comes into contact with the panel, since the lower portion of the bag is also pulled toward the vehicle occupant, a tensile force is not sufficiently generated in the panel, and therefore, the panel cannot properly protect the head.  
         [0012]     In the case of the head protection airbag disclosed in Japanese Unexamined Patent Application Publication No. 2003-72500, the supporting fabric contributes to the protection of the occupant&#39;s head. However, in order to ensure that the airbag or the supporting fabric immediately catches the head of the vehicle occupant, the thickness of a connection member of the airbag needs to be increased, which consequently increases the size of the airbag. As a result, it is necessary to employ an inflator having a large capacity.  
         [0013]     There is a general need to maximize the effective thickness (inflated thickness) of airbags. At the same time, this need to maximize the effective thickness is limited by the performance of the gas generators that are used to fill the airbags.  
         [0014]     The increase in airbag chamber thickness is currently achieved by increasing the pertinent orthogonal dimensions of the airbag. This, however, increases the volume by around the power of three in relation to the chamber thickness (this means, for instance, a volume increase of 3.4 with an increase in chamber of thickness of 1.5). When scaling the airbag cutting or airbag panel shape to the required size, all three dimensions are stretched to the same extent.  
       SUMMARY  
       [0015]     One embodiment of the invention relates to an airbag. The airbag comprises a front fabric panel connected to a rear fabric panel to form a chamber therebetween and a gusset positioned to allow the front and rear panels to separate at a point where the front and rear panels are connected by the gusset.  
         [0016]     According to another embodiment of the present invention, an occupant safety system is provided. The occupant safety system comprises an airbag with front and rear panels connected to form a chamber therebetween and a gusset configured to allow the front and rear panels to separate at a point where the gusset is connected to the front and rear panels and an inflator for inflating the airbag.  
         [0017]     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  
       [0018]     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.  
         [0019]     FIGS.  1 ( a ) and  1 ( b ) are views of an airbag according to an embodiment of the present invention.  FIG. 1 ( a ) is an exploded view of the airbag and  FIG. 11 ( b ) is a perspective view of the airbag of  FIG. 1 ( a ).  
         [0020]     FIGS.  2 ( a ) and  2 ( b ) are views of an airbag according to another embodiment of the present invention.  FIG. 2 ( a ) is an exploded view of the airbag and  FIG. 2 ( b ) is a perspective view of the airbag of  FIG. 2 ( a ).  
         [0021]     FIGS.  3 ( a ),  3 ( b ) and  3 ( c ) are views of an airbag according to another embodiment of the present invention.  FIG. 3 ( a ) is an exploded view of the airbag.  FIG. 3 ( b ) is a top perspective view of the airbag of  FIG. 3 ( a ) and  FIG. 3 ( c ) is a side perspective view of the airbag of  FIG. 3 ( a ).  
         [0022]     FIGS.  4 ( a ),  4 ( b ) and  4 ( c ) are views of an airbag according to another embodiment of the present invention.  FIG. 4 ( a ) is an exploded view of the airbag.  FIG. 4 ( b ) is a perspective view of the airbag of  FIG. 4 ( a ) and  FIG. 4 ( c ) is a bottom view of the airbag of  FIG. 4 ( a ).  
         [0023]     FIGS.  5 ( a ),  5 ( b ) and  5 ( c ) are views of an airbag according to another embodiment of the present invention.  FIG. 5 ( a ) is an exploded view of the airbag.  FIG. 5 ( b ) is a top perspective view of the airbag of  FIG. 5 ( a ) and  FIG. 5 ( c ) is an end view of the airbag of  FIG. 5 ( a ).  
         [0024]      FIG. 6  is an exploded view of an airbag of another embodiment of the present invention.  
         [0025]     FIGS.  7 ( a ) and  7 ( b ) are views of an airbag according to another embodiment of the present invention.  FIG. 7 ( a ) is a view of the airbag prior to inflation.  FIG. 7 ( b ) is a view of the airbag after inflation.  
         [0026]      FIG. 8  is a side view of an airbag with multiple gussets according to another embodiment of the present invention.  
         [0027]      FIG. 9  is a perspective view of an airbag showing the height and volume of portions of the airbag. 
     
    
     DETAILED DESCRIPTION  
       [0028]     Hereinafter, embodiments of the present invention will be described with reference to the attached drawings.  
         [0029]     According to an embodiment of the invention, an airbag arrangement is provided that permits the production of an airbag with a larger effective thickness, while increasing the airbag volume only approximately proportional to the thickness increase in respective airbag areas. The arrangement may be achieved by a particular fabric blank or panel and sewing arrangement.  
         [0030]     According to another embodiment, the operating thickness of the chambers and/or chamber parts being increased by one or more sewn-in fabric gussets.  
         [0031]     FIGS.  1 ( a ) and  1 ( b ) show an airbag  10  according to an embodiment of the present invention. The airbag  10  includes a first airbag panel  11 , a second airbag panel  12 , a third airbag panel  13  and a fourth airbag panel  14 . The first airbag panel  11  is connected to the second airbag panel  12  along a first sewn seam line  17 . The first seam line  17  follows along the periphery of the first  11  and second  12  airbag panels. The fourth airbag panel  14  is connected to the third airbag panel  13  along a second seam line  18 . The second seam line  18  follows along the periphery of the third  13  and fourth  14  airbag panels. The second  12  and third  13  airbag panels are joined together along a third seam line  19 . This third seam line  19  is follows the periphery of the second  12  and third  13  airbag panels, but is farther from the edges than the first  17  or second  18  lines.  
         [0032]     The second airbag panel  12  includes a first cutting area or opening  15  in the center of the second airbag panel  12 . The third airbag panel  13  also includes a cutting area or opening  16  in the center of the third airbag panel  13 . The seams lines  17 ,  18 ,  19  and the openings  15 ,  16  join the first  11 , second  12 , third  13  and fourth  14  airbag panels together and create a chamber inside the panels  11 ,  12 ,  13 ,  14 . The second  12  and third  13  airbag panels form a gusset for the airbag  10 , expanding the volume of the airbag  10 .  
         [0033]     FIGS.  2 ( a ) and  2 ( b ) show another embodiment of the present invention. An airbag  20  includes a first airbag panel  21 , a second airbag panel  22 , a third airbag panel  23  and a fourth airbag panel  24 . The first airbag panel  21  is connected to the second airbag panel  22  along a first seam  17 . The first seam  17  extends around the periphery of the first  21  and second  22  airbag panels except that the first seam  17  does not extend along the entire side  20   a  of the first  21  and second  22  panels. Rather the first seam  17  does not extend to meet the second end  20   b  of the first  21  or second  22  airbag panels. The position along the side  20   a  of the first  21  and second  22  airbag panels that the first seam  17  extends can vary.  
         [0034]     The third airbag panel  23  is connected to the fourth airbag panel  24  along a second seam  18 . This seam  18  is similar to the first seam  17  in that it extends around the periphery of the panels  23 ,  24 , but does not extend to meet the second end  20   b  of the third  23  or fourth  24  airbag panels.  
         [0035]     The second airbag panel  22  is connected to the third airbag panel  23  along a third seam  19 . This seam line  19  is similar to first  17  and second  18  seam lines, except that it is farther from the periphery of the second  22  and third  23  airbag panels. The second  22  and third  23  airbag panels each have a cutting area or opening  15 ,  16 .  
         [0036]     A fourth seam line  229  joins together the first  21 , second  22 , third  23  and fourth  24  airbag panels. This fourth seam line  229  extends along the width of the airbag  20 . The seams lines  17 ,  18 ,  19  and the openings  15 ,  16  join the first  21 , second  22 , third  23  and fourth  24  airbag panels together and create a chamber inside the panels  21 ,  22 ,  23 ,  24 . The second  22  and third  13  airbag panels form a gusset for the airbag  20 , expanding the volume of the airbag  20 . On one side (right in FIGS.  2 ( a ) and  2 ( b )), the airbag  20  is capable of expanding. On the other side (left side), the airbag  20  does not expand due to the fourth seam line  229  joining the first  21 , second  22 , third  23  and fourth  24  airbag panels.  
         [0037]     FIGS.  3 ( a )- 3 ( c ) show an airbag  30 , according to another embodiment of the present invention. Airbag  30  includes a first airbag panel  31 , a second airbag panel  32  and a folded panel  301 .  
         [0038]     The first airbag panel  31  is connected to the second airbag panel  32  along a seam  35 . The seam  35  does not continue along the entire circumference of the first  31  and second  32  airbag panels, but ends at an end of the first  31  and second  32  airbag panels. At the end of the airbag panels  31  and  32  without seam  35 , the folded panel  301  is joined to the panels  31 ,  32 . A portion of the folded panel  301  is connected to the first airbag panel  31  along seam  34 . The other portion of the folded panel  301  is connected to the second airbag panel  32  along seam  33 . The folded panel  301  is folded or creased along the center of the substantially circular folded panel  301  at a fold  302  and creates a separation between the first  31  and second  32  airbag panels at the connection points. The folded panel  301  acts as a gusset to increase the volume of the airbag  31 .  
         [0039]     FIGS.  4 ( a )- 4 ( c ) show another embodiment of an airbag  40  of the present invention. The airbag  40  includes a first panel  41 , a second panel  42  and a folded panel  401 .  
         [0040]     The first airbag panel  41  is connected to the second airbag panel  42  along a seam  45 . The seam  45  does not continue along the entire circumference of the first  41  and second  42  airbag panels, but ends at an end of the first  41  and second  42  airbag panels. At the end of the airbag panels  41  and  42  without seam  45 , the folded panel  401  is joined. A portion of the folded panel  401  is connected to the first airbag panel  41  along seam  44 . The other portion of the folded panel  401  is connected to the second airbag panel  42  along seam  43 . The folded panel  401  is folded or creased along the center of the substantially circular folded panel  401  and creates a separation between the first  41  and second  42  airbag panels at the connection points. Airbag  40  is similar to airbag  30  except that the gusset (folded panel  401 ) extends along the length of the airbag  40 , as opposed to an end of the airbag.  
         [0041]     Airbag  50 , according to another embodiment of the present invention, is shown in FIGS.  5 ( a )- 5 ( c ). The airbag  50  includes a first  51  and second  52  airbag panel and a folded panel  501 . The first  51  and second  52  airbag panels are connected together along seam  56 . Seam  56  does not extend along the circumference of the airbag panels  51 ,  52 , but stops at an end of the airbag  50 .  
         [0042]     Folded panel  501  attaches to the airbag  50  at the end of the airbag  50  without seam  56 . Folded panel  501  acts like a gusset for the airbag  50 . The first airbag panel  51  attaches to a portion of the folded airbag panel  501  along seam  55 . The second airbag panel  52  attaches to a portion of the folded airbag panel  52  along seam  54 . An additional seam  53  connects the folded portions of the folded airbag panel  501  together. Airbag  50  is similar to airbag  30  except that the additional seam  53  alters the inflated shape of the airbag  50 .  
         [0043]      FIG. 6  shows an airbag  60  of an additional embodiment of the present invention. The airbag  60  includes a first airbag panel  68 , a second airbag panel  61 , a third airbag panel  62  and a fourth airbag panel  63 . The second airbag panel  61  includes an opening  66  in approximately the middle of the airbag panel  61 . The first  68  and second  61  airbag panels are connected together along seam  67 . The third  62  and fourth  63  airbag panels are connected together along seam  64 . The third airbag panel  62  also includes an opening  66  in the middle of the airbag panel  62 . The third airbag panel  62  is connected to the second airbag panel  61  along seam  65 , such that the openings  66  in both the second  61  and third  62  airbag panels align. In this airbag  60 , when gas inflates the airbag  60  by entering the chamber between the first  68  and second  61  airbag panels, gas will exit the opening  66  in the second airbag panel  61 , pass through the opening  66  in the third airbag panel  62  and enter the chamber between the third  62  and fourth  63  airbag panels.  
         [0044]     In another embodiment of the present invention, as shown in FIGS.  7 ( a ) and  7 ( b ), an airbag  70  is provided. The airbag  70  includes a first airbag panel  71  and a second airbag panel  72 . The length of the first airbag panel  71  is greater than the length of the second airbag panel  72 . In the uninflated state, shown in  FIG. 7 ( a ), the first  71  and second  72  panels are stitched together along seams  74 , which form chambers in the airbag  70 . Because the first airbag panel  71  is longer, the panel  71  includes surplus sections  73  which are additional material. These surplus sections  73  are folded over in the uninflated state. When the airbag  70  is deployed and inflates, the surplus sections  73  create rounded sections, as can be seen in  FIG. 7 ( b ).  
         [0045]     According to another embodiment of the present invention, an airbag  80  can include a plurality of gussets. For example, as shown in  FIG. 8 , an airbag  80  can include first  81  and second  83  airbag panels attached along a seam  85 . At each end of the airbag  80 , a gusset comprising a folded panel  82 ,  84  can be sewn to the airbag  80 . Folded panel  82  includes a fold  82   a  or crease and folded panel  84  includes a fold  84   a  or crease.  
         [0046]     According to another embodiment of the present invention shown in  FIG. 9 , the volume reduction factor of an airbag  90  can be less than one. The volume reduction factor is calculated by the volume V of the inflated chamber of the gusseted airbag  90  divided by the product of the surface area SA of the smaller of the first  91  or second  92  fabric panels in the inflatable area and the maximum distance H between the first  91  and second  92  panels at the gusset  93 . According to another embodiment of the present invention, the ratio of a volume reduction factor is less than 0.8. According to another embodiment of the present invention, the ratio of a volume reduction factor is less than 0.6.  
         [0047]     The fabric gussets  93  result in an increased operating thickness of the inflated and pressurized airbag  90  chamber without significantly increasing the chamber expansion in other dimensions. According to one embodiment of the invention, the operating thickness of an airbag  90  with applied gussets  93  being at least 10% higher compared to an airbag without gussets and with the same circumferential seam.  
         [0048]     The effective thickness, according to an embodiment of the present invention, is increased so that an increase in volume is only possible in one space direction. Generally, all seams on the two-dimensional plane or all cuttings placed on top of each other can be sewn in the production process. The cuttings are all sewn together in a two-dimensional manner so that during inflation, parts of the fabric rise to an upright position in the third dimension. This is achieved by at least one layer that is sewn in between the two outer seams or layers that are folded in and which rise asymmetrically to an upright position when the airbag is filled.  
         [0049]     According to an embodiment of the present invention, the seams may be siliconized or not siliconized in order to withstand higher pressure.  
         [0050]     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.