Abstract:
An improved airbag ( 10 ) is provided that can be sequentially deployed for minimizing the risk of injury to a vehicle occupant ( 12 ). This improved airbag ( 10 ) is an inflatable bag having a primary chamber ( 34 ) and a secondary chamber ( 36 ) that is adjacent to the primary chamber ( 34 ). The primary chamber ( 34 ) is configured for inflating before the secondary chamber ( 36 ). In addition, this primary chamber ( 34 ) is utilized for applying a generally downward force the vehicle occupant&#39;s lap ( 14 ) and abdomen ( 16 ). In this way, a substantial portion of the initial deployment force of the airbag ( 10 ) is allocated to the occupant&#39;s more durable lower body. Also, the primary chamber ( 34 ) can be utilized for positioning the occupant&#39;s body ( 12 ) in a manner best suited for impacting the airbag ( 10 ). This airbag ( 10 ) is then sequentially deployed in a generally linear direction upward from the primary chamber ( 34 ) to the secondary chamber ( 36 ).

Description:
BACKGROUND OF INVENTION  
       [0001]     The present invention relates generally to supplemental restraint systems of vehicles, and more particularly to an improved airbag that can be sequentially deployed for minimizing the risk of injury to an occupant&#39;s head and neck.  
         [0002]     Driver&#39;s side airbags for supplemental restraint systems of vehicles are well known. Typical driver&#39;s side airbags are comprised of one or more panels, which form either a single chamber construction or a multiple chamber construction. One of these panels usually includes an inlet that is located at a center position of the panel. This inlet typically allows an inflator device to inject gas into the airbag for deploying the airbag.  
         [0003]     The internal construction of these airbags usually causes the airbags to be deployed radially from the center outward. In this regard, various circumferential portions of the airbag can be simultaneously inflated with a substantially equal amount of force. In other words, the portions of the airbag intended to cushion the occupant&#39;s head and neck can be inflated at substantially the same time and with substantially the same force as the portions of the airbag intended to cushion the occupant&#39;s abdomen and lap.  
         [0004]     A drawback of these airbags is that their radial deployment can result in substantial injuries to the occupant&#39;s head or neck. Specifically, it is understood that the force required to initially deploy or “punch out” the airbag from its steering-wheel housing can be substantially high. In particular, such a force can be sufficiently high for injuring the occupant&#39;s head or neck as the airbag impacts those body parts. Although the radial deployment of the airbag typically causes the airbag to impact the various parts of the occupant&#39;s body at substantially the same time and with substantially the same force, it will be appreciated that the occupant&#39;s abdomen and lap are less likely to be injured because those body parts typically are more durable for withstanding greater forces. Furthermore, it will be appreciated that the risk of injury can substantially increase when the occupant is sitting out of position. In particular, the deployment of existing airbags may substantially injure a driver&#39;s head or neck if the driver is leaning farther forward than a standard upright sitting position.  
         [0005]     Another drawback of these airbags is that the radial deployment of the airbags usually does not control the kinematics of the occupant&#39;s body for minimizing his risk of injury. Specifically, the radial deployment of these airbags is merely intended to cushion or dampen the overall forces distributed to the occupant&#39;s entire body. In this respect, the radial deployment of these airbags typically does not control the method by which various parts of the occupant&#39;s body impact the airbag. As a result, one or more parts of the occupant&#39;s body may be positioned poorly for impacting the airbag. For example, the airbag may impact an occupant beneath his chin, e.g. his larynx, and force his head upward and rearward. Such a force can create substantial pressure in the vertebrae of the occupant&#39;s neck and possibly result in a serious neck injury.  
         [0006]     Therefore, a need exists for an improved airbag with internal panel structure for sequentially deploying the airbag and decreasing an occupant&#39;s risk of injury as he impacts the airbag.  
       SUMMARY OF INVENTION  
       [0007]     The present invention provides an improved airbag with one or more internal positioning panels for sequentially deploying the airbag and minimizing the risk of injury to a vehicle occupant. This improved airbag is an inflatable bag having a primary chamber and a secondary chamber that is adjacent to the primary chamber. The primary chamber is configured for inflating before the secondary chamber. In addition, this primary chamber is utilized for applying a generally downward force to a lower-body portion of the vehicle occupant. In this way, a substantial portion of the initial deployment force of the airbag is allocated to the occupant&#39;s more durable lower-body portion. Also, the primary chamber can be utilized for positioning the occupant&#39;s body in a manner best suited for impacting the airbag. This airbag is then sequentially deployed in a generally linear direction upward from the primary chamber to the secondary chamber.  
         [0008]     One advantage of the present invention is that an improved airbag is provided that controls the kinematics of an occupant&#39;s body and the method by which he impacts the airbag so as to decrease his risk of injury.  
         [0009]     Another advantage of the present invention is that an improved airbag is provided that distributes a greater portion of the airbag&#39;s initial deployment force to portions of the occupant&#39;s body, which are better suited for withstanding those forces without incurring an injury.  
         [0010]     Yet another advantage of the present invention is that an improved airbag is provided that furnishes immediate protection for an occupant&#39;s head and neck.  
         [0011]     Still another advantage of the present invention is that an improved airbag is provided that is sequentially deployable for decreasing the impact force between the airbag and the occupant&#39;s head and neck.  
         [0012]     Other advantages of the present invention will become apparent upon considering the following detailed description and appended claims, and upon reference to the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0013]     For a more complete understanding of this invention, reference should now be made to the embodiments illustrated in greater detail in the accompanying drawings and described below by way of the examples of the invention:  
         [0014]      FIG. 1A  is a perspective view of an improved airbag in a first stage of sequential deployment, according to one embodiment of the present invention.  
         [0015]      FIG. 1B  is a cross-sectional view of the improved airbag shown in  FIG. 1A .  
         [0016]      FIG. 1C  is a front view of the improved airbag shown in  FIG. 1A .  
         [0017]      FIG. 2A  is a perspective view of the improved airbag, shown in  FIG. 1A , illustrating the airbag in a second stage of sequential deployment.  
         [0018]      FIG. 2B  is a cross-sectional view of the improved airbag shown in  FIG. 2A .  
         [0019]      FIG. 2C  is a front view of the improved airbag shown in  FIG. 2A .  
         [0020]      FIG. 3A  is a perspective view of the improved airbag shown in  FIG. 1A , illustrating the distribution of an initial airbag deployment force to a vehicle occupant&#39;s lower-body region during the first stage of sequential deployment, according to one embodiment of the present invention.  
         [0021]      FIG. 3B  is a perspective view of the improved airbag shown in  FIG. 2A , illustrating the controlled cushioning of the vehicle occupant&#39;s head and neck during the second stage of sequential deployment, according to one embodiment of the present invention.  
         [0022]      FIG. 4  is an exploded view of a series of panels utilized to form the improved airbag shown in  FIGS. 1A-2C .  
         [0023]      FIG. 5A  is a cross-sectional view of the improved airbag shown in  FIG. 2B , illustrating an alternative construction of panels of the improved airbag, according to another embodiment of the invention; and.  
         [0024]      FIG. 5B  is an exploded view of a series of panels utilized to form the improved airbag shown in  FIG. 4B . 
     
    
     DETAILED DESCRIPTION  
       [0025]     In the following figures, the same reference numerals are used to identify the same components in the various views.  
         [0026]     The present invention is particularly suited for an improved driver&#39;s side airbag for sequential two-stage deployment and minimizing a risk of injury during a front-end crash. In this regard, the embodiments described herein employ structural features where the context permits. However, it is understood that a variety of other embodiments without the described features are contemplated as well. For example, the improved airbag can be utilized for protecting various vehicle occupants besides the driver and in a variety of collisions, instead of front-end crashes. For this reason, it follows that the invention can be carried out in various other modes and utilized for other suitable applications as desired.  
         [0027]     Referring to  FIGS. 1A and 2A , there are shown perspective views of an improved airbag  10 , respectively illustrating the improved airbag  10  in a first stage of sequential deployment and a second stage of sequential deployment, according to one embodiment of the invention.  
         [0028]     With particular attention to  FIGS. 3A-3B , it will be appreciated that the improved airbag  10  can minimize the risk of injury to a vehicle occupant  12 , e.g. a driver, during a front-end collision. As shown in  FIG. 3A , the first stage of deployment can cause the airbag  10  to apply a substantial portion of the “punch out” force to the driver&#39;s lap  14  and lower abdomen  16 . As is known, this “punch out” force or initial deployment force typically is powerful because it must be sufficiently strong for breaking the airbag  10  out of its steering-wheel housing  18  within a short period of time. This feature is beneficial because it can direct this typically strong deployment force to a portion of the occupant&#39;s body, which is sufficiently durable for withstanding such a force. Specifically, it is understood that a person&#39;s lap  14  and lower abdomen  16  usually are better suited for withstanding a substantial blow than the person&#39;s head  20  and neck  22 .  
         [0029]     During the first stage of sequential deployment, the improved airbag  10  also controls the kinematics of the vehicle occupant  12  for preparing him to impact the remainder of the airbag  10  during the second stage of deployment. For example, as seen in  FIG. 3A , during the first stage of deployment, the improved airbag  10  can contact the occupant&#39;s lower body and move the occupant&#39;s body in a manner that causes him to tuck in his chin  26 . Thereafter, during the second stage of deployment as shown in  FIG. 3B , the remainder of the airbag  10  can inflate in a controlled and timely manner such that the occupant  12  impacts the remainder of the airbag  10  with his chin tucked in. This positioning of the occupant&#39;s body can prevent the inflating airbag  10  from contacting the occupant underneath his chin  26  and forcing his head  20  upward and rearward. It will be understood that this feature prevents substantial pressure from being applied to the occupant&#39;s neck  22 , which can result in a serious injury. In addition to this example, it is also contemplated that the sequential deployment of the improved airbag  10  can also position the occupant&#39;s body in various other ways for preventing a variety of injuries.  
         [0030]     Furthermore, in the first stage of deployment, the improved airbag  10  includes a vertical columnar portion for providing immediate protection for the occupant&#39;s upper body region, e.g. his head and neck. This vertical columnar portion is defined by an upper sub-chamber  42  of the airbag  10  (as detailed in the description for  FIGS. 1B and 1C ).  
         [0031]     Referring now to  FIGS. 1B, 2B , and  4 , it can be seen that the improved airbag  10  is an inflatable bag comprised of three interconnected panels. Specifically, these panels include a first outer panel  28  and a second outer panel  30 , which is sized substantially similar to the first outer panel  28 . The first and second outer panels  28 ,  30  are attached to each other at their peripheries via stitching or various other suitable fastening methods. Additionally, the first and second outer panels  28 ,  30  have an inner panel  32  attached therebetween via stitching or various other suitable fastening methods. This inner panel  32  is utilized for partitioning the interior of the airbag  10  into a primary chamber  34  and a secondary chamber  36  (shown in  FIG. 2B ). The primary chamber  34  is inflated during the first stage of deployment before the secondary chamber  36  is inflated during the second stage of deployment.  
         [0032]     However, it will be appreciated that the inflatable bag can instead be comprised of only one panel, two panels, or various other numbers of panels as desired. For example, in another embodiment illustrated in  FIGS. 5A and 5B , the improved airbag is comprised of two panels. These panels include one outer panel  28 ″ and an inner panel  32 ″.  
         [0033]     With particular attention to  FIG. 1B , the first outer panel  28  has a primary inlet  38  formed therein for attachment to an inflator device  40 . This inflator device  40  injects gas through the primary inlet  38  directly into the primary chamber  34 . In this way, the inflator device  40  can inflate the primary chamber  34  during the first stage of deployment.  
         [0034]     The primary chamber  34  includes an upper sub-chamber  42  and a lower sub-chamber  44 , which together extend substantially across a height of the improved airbag  10 . As respectively shown in  FIGS. 1B and 1C , the lower sub-chamber  44  extends substantially across a depth and a width of the improved airbag  10 . This construction allows the lower sub-chamber  44  to apply a substantial portion of the initial deployment force across the vehicle occupant&#39;s lap and lower abdomen.  
         [0035]     Moreover, as seen in  FIGS. 1B and 1C , the upper sub-chamber  42  is sized substantially smaller than the lower sub-chamber  44  along the depth and the width of the airbag  10 . In this regard, the upper sub-chamber  42  has a substantially vertical columnar construction for directing the gas in a generally downward direction into the lower sub-chamber  44 . For that reason, the airbag  10  deploys in a generally downward direction during the first stage of deployment. It is also understood that the inflation of the upper sub-chamber  42  can absorb a portion of the initial deployment force thereby decreasing the risk of harm to the occupant  12  when the airbag  10  ultimately impacts the occupant&#39;s head  20  and neck  22 .  
         [0036]     Although the upper sub-chamber  42  is sized smaller than the lower sub-chamber  44 , it will be appreciated that the upper sub-chamber  42  is sized sufficiently large for providing immediate protection for the occupant&#39;s upper body region during the first stage of deployment.  
         [0037]     The inner panel  32  has a secondary inlet  46  formed therein for permitting gas to flow from the primary chamber  34  to the secondary chamber  36  during the second stage of deployment. However, during the first stage of deployment, the secondary chamber  36  is held in a collapsed or deflated configuration until the primary chamber  34  is substantially inflated and a threshold pressure has been built up within the primary chamber  34 . Specifically, the second outer panel  30  is attached to the inner panel  32  by a releasable tether  48 . In this way, the releasable tether  48  can restrict the size of the secondary chamber  36  and prevent that portion of the airbag  10  from being inflated. The releasable tether  48  detaches from either the inner panel  32  or the second outer panel  30  when sufficient pressure has built up in the primary chamber  34 , e.g. after that chamber  34  has been fully deployed. Thereafter, the secondary chamber  36  of the airbag  10  can be inflated during the second stage of deployment.  
         [0038]     In one embodiment, the releasable tether  48  is a relatively small amount of stitching with a substantially weak threading. In that regard, the threading can break when gas flows into the secondary chamber  36  with sufficient pressure. However, it is understood that the releasable tether  48  can instead be various other suitable tethers as desired.  
         [0039]     Referring back to  FIGS. 1B and 2B , the secondary inlet  46  is one or more open vent holes formed within the inner panel  32 . In this regard, the open vent holes allow for the free flow of gas between the primary chamber  34  and the secondary chamber  36 .  
         [0040]     In another embodiment, the secondary inlet  46  is a baffle vent for metering the flow of gas into the secondary chamber  36 . As a result, the baffle vent can further control the timing and force by which the secondary chamber is deployed. This feature is beneficial because it can decrease the speed and the force by which the secondary chamber  36  inflates. This controlled inflation likewise decreases the speed and the force by which the airbag  10  impacts the occupant&#39;s relatively fragile head  20  and neck  22 .  
         [0041]     In yet another embodiment, the secondary inlet  46  is simply a permeable fabric comprising the inner panel  32  or a portion thereof. Similar to the baffle vent, this permeable fabric can meter the flow of gas into the secondary chamber  36  and further protect the occupant&#39;s head  20  and neck  22 .  
         [0042]     With particular attention to  FIG. 2B , the improved airbag  10  further includes a fixed tether  50  attached to and in connection between the second outer panel  30  and the inner panel  32 . This fixed tether  50  restricts the second outer panel  30  from bulging outward and maintains an overall uniform depth of the airbag  10  when the secondary chamber  36  is inflated in the second stage of deployment. As shown in  FIGS. 2B and 2C , the secondary chamber  36  extends substantially across the width and the depth of the improved airbag  10 . For that reason, the controlled deployment of the secondary chamber  36  can cushion the occupant&#39;s head  20  and neck  22  and decrease the risk of injury to those body parts.  
         [0043]     While particular embodiments of the invention have been shown and described, it will be understood, of course, that the invention is not limited thereto since modifications may be made by those skilled in the art, particularly in light of the foregoing teachings. Accordingly, it is intended that the invention be limited only in terms of the appended claims.