Abstract:
An airbag cushion is disclosed for use in automotive protective systems. The airbag cushion includes a tube that may be restricted to prevent gas venting. A cord is coupled to the tube and to a surface of the cushion. Upon airbag deployment, the cord extends until taut or extends until the cushion encounters an obstruction. If pulled taut, the cord tightens the tube and restricts gas venting. If the cushion encounters an obstruction, the cord remains lax and the tube is able to vent gas.

Description:
TECHNICAL FIELD  
       [0001]     The present invention relates generally to the field of automotive protective systems. More specifically, the present invention relates to inflatable airbags for automobiles. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0002]     Understanding that drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:  
         [0003]      FIG. 1A  is a cross-sectional view of an embodiment of a deploying airbag cushion.  
         [0004]      FIG. 1B  is a cross-sectional view of the deploying airbag cushion of  FIG. 1A .  
         [0005]      FIG. 1C  is a cross-sectional view of an embodiment of a deploying airbag cushion of  FIGS. 1A and 1B .  
         [0006]      FIG. 2A  is a perspective view of an embodiment of a cinch tube.  
         [0007]      FIG. 2B  is a perspective view of the cinch tube of  FIG. 2A .  
         [0008]      FIG. 3A  is a cross-sectional view illustrating initial deployment of an airbag cushion.  
         [0009]      FIG. 3B  is a cross-sectional view illustrating a deploying airbag cushion.  
         [0010]      FIG. 3C  is a cross-sectional view of a deployed airbag cushion.  
         [0011]      FIG. 3D  is a cross-sectional view illustrating initial deployment of an airbag cushion.  
         [0012]      FIG. 3E  is a cross-sectional view illustrating a deploying airbag cushion.  
         [0013]      FIG. 3F  is a cross-sectional view of a deployed airbag cushion.  
         [0014]      FIG. 4  is a diagram illustrating an airbag cushion venting graph in relation to an airbag cushion&#39;s deployment.  
         [0015]      FIG. 5  is a cross-sectional view of an alternative embodiment of a deployed airbag cushion.  
         [0016]      FIG. 6  is a side view of one embodiment of a cinch tube.  
         [0017]      FIG. 7  is a side view of one embodiment of a cinch tube. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0018]     Described below are embodiments of an airbag cushion and venting mechanism. As those of skill in the art will appreciate, the principles of the invention may be applied to and used with a variety of airbag deployment systems including frontal driver and passenger airbags, knee airbags, overhead airbags, curtain airbags, and the like. Thus, the present invention is applicable to airbag cushions of various shapes and sizes.  
         [0019]     Airbag cushions are frequently located in an instrument panel and directly in front of an occupant. During a collision, the airbag cushion inflates and deploys through a cosmetic cover. The airbag cushion deploys towards the occupant and provides a restraint. A dangerous situation occurs where an occupant is positioned to closely to the airbag which causes the occupant to contact the airbag as it is deploying. Ideally, the occupant should be in position to contact the airbag only after full deployment. It would be advantageous to provide an airbag with a softer deployment when an occupant is out-of-position. Embodiments described below provide an airbag cushion that responds to an occupant&#39;s position and vents accordingly to avoid excessive deploying impact.  
         [0020]     Embodiments disclosed herein include a cinch cord that is connected at one end to a cinch tube and at an opposing end to an interior surface of the cushion. If an occupant is in close proximity to the deploying airbag and restricts normal inflation, the cinch tube remains open and allows gas to rapidly escape. If the occupant is in a normal position and inflation is unrestricted, the tension pulls on the cinch tube to quickly close the cinch tube. Closure retains gas for normal occupant restraint. Thus, the cinch tube may be used as a variable feature in out-of-position conditions and in normal restraint conditions. In this manner, the airbag cushion is sensitive to obstructive expansion of the cushion.  
         [0021]     With reference now to the accompanying figures, particular embodiments of the invention will now be described in greater detail.  FIGS. 1A through 1C  depicts a cross-sectional view of an airbag cushion  100  deploying from a housing  10 . The airbag cushion  100  includes a cinch tube  102  that may include a nylon woven fabric-type or other suitable material known in the art. The cinch tube  102  may be embodied with a generally cylindrical shape and having opposing open ends to enable gas venting. The cinch tube  102  may have any suitable shape such as rectangular, triangular, or polygon shapes. The cinch tube  102  may be embodied with a height that is sufficient to achieve desired closure.  
         [0022]     The cinch tube  102  is coupled to a surface  104  of the airbag cushion  100  and circumvents an aperture  106  in the surface  104 . The surface  104  may form part of an airbag cushion throat  108  or may be proximate to the throat  108 . The cinch tube  102  may extend into the airbag cushion interior  110  or may extend from the airbag cushion  100 . For illustrative purposes, a single cinch tube  102  is disclosed but the airbag cushion  100  may include multiple cinch tubes to provide required venting capability.  
         [0023]     The airbag cushion  100  includes a cinch cord  112  that couples or engages the cinch tube  102  and couples to a surface  114  of the airbag cushion  100 . The cinch cord  112  may include a nylon material or other suitable material known in the art. The surface  114  may be an interior surface of the airbag cushion as depicted. The surface  114  may be the surface opposing the face surface  116  of the airbag cushion that contacts the occupant. Alternatively, the surface  114  may be disposed proximate to a surface opposing the face surface  116 . The surface  114  may be an exterior surface such as the face surface  116 . Thus, the cinch cord  112  may extend through the interior  110  of the airbag cushion  100  or may be positioned exterior to the airbag cushion  100 . The location of the surface  114  depends on module deployment angle, vehicle interior geometry, and cushion fold type.  
         [0024]     In  FIG. 1A , the initially deploying airbag cushion  100  has a slack cinch cord  112  and the cinch tube  102  remains open. In  FIG. 1B , the cinch cord  112  is pulled taut and the cinch tube  102  begins to close. In  FIG. 1C , the cinch cord  112  is completely taut and the cinch tube  102  is closed.  
         [0025]     Referring to  FIGS. 2A and 2B , perspective views of one embodiment of a cinch tube  102  in both the open and closed positions are shown. The cinch cord  112  circumvents a majority of the perimeter  200  of the cinch tube  102  in order to properly tighten and restrict the cinch tube  102 . The cinch cord  112  has a length that includes an initial free length and a circumference of the cinch tube  102 . The cinch cord  112  may be disposed within a sleeve  202  that is formed within the cinch tube  102 . Access to the sleeve  120  is through a sleeve aperture  204  formed in the cinch tube  102 . The cinch cord  112  enters the sleeve aperture  204 , feeds through the sleeve  202 , and is coupled at an end  206  within the sleeve  120  to the cinch tube  102 . Coupling may be achieved by stitches, bonds, or adhesives.  
         [0026]     Referring to  FIG. 3  an alternative embodiment of a cinch tube  300  is shown wherein a cinch cord  302  loops around the majority of the cinch tube perimeter  304 . The cinch tube  300  includes first and second sleeve apertures  306 ,  308  that are in communication with a sleeve  310  formed within the cinch tube  300 . The cinch cord  302  enters the first sleeve aperture  306 , extends along the sleeve  310 , and exits out the second sleeve aperture  308 .  
         [0027]     Referring to  FIG. 4 , an alternative embodiment of a cinch tube  400  is shown wherein the cinch tube  400  includes a plurality of cinch loops  402 . The cinch loops  402  may be disposed on a periphery  404  as shown or on an inner or outer surface  406 ,  408  of the cinch tube  400 . A cinch cord  410  is fed through the cinch loops  402  and is thereby able to restrict the cinch tube  400  as needed.  
         [0028]     FIGS.  5 A-C illustrate three stages of a deploying airbag cushion  500  without obstruction in the deploying path. The depicted airbag cushion  500  includes two cinch tubes  502  symmetrically disposed on the cushion  500  and two vents  504  symmetrically disposed on the cushion  500 . The vents  504  provide consistent venting of the airbag cushion  500  and are not restricted by an occupant&#39;s position. The vents  504  may be optional in certain cushion embodiments based on venting requirements. The locations for the cinch tubes  502  and vents  504  may vary as does the number of tubes  502  and vents  504 . An occupant  12  is in a normal seating position which will allow the airbag cushion  500  to fully expand before impacting the occupant. In this manner, the occupant  12  benefits from the full restraint capability of the airbag cushion  500 .  
         [0029]     In  FIG. 5A , the initial breakout of the airbag cushion  500  occurs. The cinch tubes  502  are open and, in the depicted embodiment, extend from the airbag cushion  500 . In  FIG. 5B , cinch cords  506  corresponding to each cinch tube  502  are pulled taut and the cinch tubes  502  are restricted. The cinch tubes  502  may also be pulled within the interior  508  of the airbag cushion  500 . In  FIG. 5C , the cinch tubes  502  are completely closed, the gas vents through the vents  504 , and normal restraint is provided to the occupant  12 .  
         [0030]     FIGS.  5 D-F illustrate three stages of a deploying airbag cushion  500  with obstruction in the deploying path. An occupant  12  is out-of-position and obstructs the deploying airbag cushion  500  and prevents the airbag cushion  500  from fully inflating. In  FIG. 5D , the airbag cushion  500  begins initial deployment as in  FIG. 5A . In  FIG. 5E , the airbag cushion  500  impacts the occupant  12  and the cinch cords  506  remain slack. The cinch tubes  502  remain open and venting rapidly occurs from tubes  502  and vents  504 . The cushion inflation is restricted but the occupant  12  receives less than the full deployment loading of the cushion  500 . In  FIG. 5F , the cushion  500  is partially inflated and provides limited restraint. Venting continues through the tubes  502  and vents  504 .  
         [0031]     Referring to  FIG. 6 a  graph illustrating cinch tube venting as a function of airbag cushion displacement is shown. For reference, an airbag cushion  600  is shown in various stages of deployment. The airbag cushion  600  includes two symmetrically disposed cinch tubes  602 . During initial deployment, the airbag cushion  600  is unfolding and the cinch tubes  602  provide little or no venting. The airbag cushion  600  expands into an out-of-position zone  604  where, if obstructed, the cinch tubes  602  will remain completely or nearly open and full venting occurs. In this zone an occupant does not receive the full restraint capability but does benefit from limited restraint. If unobstructed, the airbag cushion  600  expands into a gray zone  606  where partial closure of the cinch tubes  602  begins and venting is limited. The cinch tubes  602  may be pulled into the airbag cushion  600  depending on the cushion design. If further unobstructed, the airbag cushion  600  fully expands to the restraint zone  608 . At this zone, the cinch tubes  602  completely close and an occupant benefits from the full restraint capability of the airbag cushion  600 .  
         [0032]     Referring to  FIG. 7 , an alternative embodiment of an airbag cushion  700  is shown. The airbag cushion  700  includes two symmetrical cinch tubes  702  that may be embodied as described above. The cinch tubes  702  have been pulled completely into the airbag cushion interior  704 . Rather than having cinch cords corresponding to each cinch tube  702 , a single cinch cord  706  is used. The cinch cord  706  is coupled to or engages each cinch tube  702  in a manner similar to that previously described. The cinch cord  706  passes through a cord loop  708  that is coupled to an interior surface  710 . The cord loop  708  may be formed of a fabric material similar or identical to that of the airbag cushion  700 . The cinch cord  706  may freely pass through the loop  708  and may therefore be referred to as a “floating” cinch cord. In an alternative embodiment, the cinch cord  706  may be disposed on the airbag cushion exterior and passes through a cord loop  708  coupled to an exterior surface of the airbag cushion  700 . In either embodiment, airbag cushion deployment pulls the cinch cord  706  taut and closes both cinch tubes  702 .  
         [0033]     Referring to  FIG. 8 , an alternative embodiment of a cinch cord  800  disposed within a cinch tube  802  is shown. The cinch tube  802  includes a sleeve  604  that extends around a periphery of the cinch tube  802  and houses a portion of the cinch cord  800 . The cinch cord  800  exits from the sleeve  804  through a sleeve aperture  806 . The cinch cord  800  includes a stopper  808  that, prior to airbag cushion deployment, is disposed within the sleeve  804 . The stopper  808  is sized and configured to permit deploying movement, i.e. from the sleeve  804  and through the aperture  806 , but does restricts movement through the aperture  806 . In operation, the stopper  808  prevents a cinch tube  802  from reopening after deployment and closure of the cinch tube  802 . This may occur during deflation of an airbag cushion as the cinch cord becomes slack. Venting is thereby directed to other vents.  
         [0034]     Referring to  FIG. 9 , an alternative embodiment of a cinch tube  900  is shown with a cinch cord  902  partially disposed within. The cinch tube  900  includes a sleeve  904  that contains a portion of the cinch cord  902 . The cinch tube  900  further includes tack stitching  906  that is inserted through the sleeve  904  and the cinch cord  902  to retain the cinch cord  902  and prevent inadvertent closing of the cinch tube  900  during shipping and handling. The tack stitching  906  is designed to be easily broken and provides no interference to airbag cushion deployment.  
         [0035]     Embodiments disclosed herein illustrate novel techniques for venting an airbag cushion to retain an open vent when an occupant obstructs the path of a deploying cushion and closed when an occupant does not obstruct a deploying cushion. Airbag cushions provide improved safety by deploying with less pressure when an occupant is obstructing deployment. The airbag cushions deploy with more pressure when an occupant is not obstructing deployment and when high pressure is required to provide the necessary restraint. The airbag cushions described herein have application to both driver and passenger positions. Furthermore, the airbag cushions may be configured in a variety of sizes based on design constraints.  
         [0036]     Various embodiments for cinch tubes have been disclosed herein. Venting means refers to cinch tubes  102 ,  300 ,  400 ,  502 ,  602 ,  702 ,  802 , and  900 . Restricting means refers to cinch cords  112 ,  302 ,  410 ,  506 ,  706 ,  800 , and  902 ,  
         [0037]     It will be apparent to those having skill in the art that changes may be made to the details of the above-described embodiments without departing from the underlying principles of the invention. Embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows. Note that elements recited in means-plus-function format are intended to be construed in accordance with 35 U.S.C. § 112 ¶6.