Abstract:
An inflatable passenger restraint airbag having an inflatable and transferable gas vent is disclosed. A system and method is provided whereby the force of airbag deployment may be reduced in real time if the airbag strikes an out of position seat occupant. This force reduction is made possible by release of inflation gas at an early stage of deployment through an adjustable gas vent. This gas vent is operable between an open venting position and a closed non-venting position. Whether or not the transfer of the vent occurs in a given deployment situation is determined by the presence or absence of an out of position obstruction in the pathway of the airbag.

Description:
BACKGROUND 
       [0001]    Automotive safety restraint airbags have achieved widespread acceptance. Airbags reliably save lives in the event of collision. Airbags may be divided into several types, including frontal impact type airbags and side curtain (rollover) type airbags. Both types of airbags use explosive charges to inflate rapidly a textile to decelerate the passenger. 
         [0002]    In normal operation, frontal impact airbags are essentially inflated in only a few milliseconds. By design, frontal impact airbags are typically inflated prior to the time the seated passenger fully impacts the airbag with his or her face and head. Upon impact, the passenger “rides” down on the airbag as the airbag deflates, with gas escaping through conventional holes in the underside of the airbag. Such controlled deflation is designed to occur during impact of the passenger upon the airbag. This mechanism softens the impact to the upper body of the passenger during collision. 
         [0003]    In the event of a passenger that is not at the time of collision resting in the normal upright seated position, airbags may not be effective. In some cases of such “out of position” passengers, airbags can be harmful to the occupant. If a passenger is unusually close to the dashboard or airbag deployment point at the time of collision, then the explosion of the airbag into the passenger&#39;s head or upper body may cause injury or death. Various designs have been used in an attempt to remedy the “out of position” (“OOP”) passenger situation. 
         [0004]    One manner of dealing with the OOP passenger situation uses electronic sensors to sense if a passenger is in the normal seated position at the time of impact. Sensors may be deployed in the seat to determine the location or mass of a person, and whether or not a person is resting on the seat. Other sensors may be used to electronically determine if an object or passenger is located too close to the airbag deployment location at the time of impact. When an OOP passenger is detected, the force of the airbag deployment electronically may be adjusted to reduce the risk of passenger injury. This may occur by reducing or eliminating a portion of the inflation mechanism, thereby reducing the release of the gas charge into the airbag. 
         [0005]    One disadvantage of such electronic sensors is that sensors are not always reliable, and they are subject to variability. Furthermore, sensors are subjected to extreme temperatures in the interior of automobiles. Heat and age may damage electronic components. Such sensors may be in the automobile for many years before they are actually activated in airbag deployment. Thus, sensor age may contribute to the failure of the sensors. Electronic sensors typically add significant financial cost to an airbag deployment system. 
         [0006]    What is needed in the industry is a reliable and relatively inexpensive system for providing a reduced force airbag deployment in the event of an out of position passenger. This invention is directed to such an airbag, system and method. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  shows a passenger in an upright seat-belted position; 
           [0008]      FIG. 2  illustrates an airbag deployed in the initial stage of a collision, before the passenger has moved forward into the airbag; 
           [0009]      FIG. 3  represents a different set of circumstances as compared to  FIGS. 1-2 , in which an obstruction of an out of position passenger (OOP) has his or her upper body and head undesirably near the dashboard or steering wheel at the exact time of collision, which results in the airbag undesirably deploying into and striking the head and upper body of the out of position passenger; 
           [0010]      FIG. 4  shows an inflatable and transferable vent of the airbag of the invention, in the open venting position, which corresponds to  FIG. 3  deployment; 
           [0011]      FIG. 5  reveals the transfer of a gas vent from an open venting position to a closed non-venting position, which occurs in the normal unobstructed deployment illustrated in  FIGS. 1-2  and  7 - 8 ; 
           [0012]      FIG. 6  illustrates the final stage of vent transfer where vent is part of the tethering system, resulting in substantial closure of the adjustable gas vent, corresponding to  FIGS. 2 and 8 ; 
           [0013]      FIG. 6A  illustrates one potential embodiment of the inflatable and transferable vent; 
           [0014]      FIG. 6B  shows another embodiment of the gas vent; 
           [0015]      FIG. 7  illustrates a top view of an early stage deployment similar to that shown in  FIG. 2 , wherein the leading edge of the unobstructed airbag is applying tension to the tethers, which pulls on the adjustable, inflatable and transferable vents; and 
           [0016]      FIG. 8  shows the situation of  FIG. 7  at a later point in time, in which the tethers which are part of the inflatable and transferable vents have pulled the gas vents from the exterior side to the interior side of the primary inflatable enclosure, resulting in closure of the gas vents. 
           [0017]      FIG. 9A  reveals an alternate embodiment of the invention, with an alternate configuration for the inflatable and transferable vent, using a cross sectional view along lines  9 A- 9 A; 
           [0018]      FIG. 9B  is a top view of the device shown in  FIG. 9A ; 
           [0019]      FIG. 9C  is a side perspective view; 
           [0020]      FIG. 9D  shows the same embodiment in the closed venting configuration; 
           [0021]      FIGS. 10A-10E  shows yet another alternate embodiment of an inflatable and transferable vent; 
           [0022]      FIGS. 11A-E  show yet another additional embodiment of the invention with inflatable and transferable vent; and 
           [0023]      FIGS. 12A-E  show another alternate embodiment of the invention, using a somewhat different configuration of the gas vent  130 . 
       
    
    
     DESCRIPTION OF THE INVENTION 
       [0024]    An inflatable passenger restraint airbag, system, and method for using such an airbag are provided. The airbag includes a primary inflatable enclosure, the primary inflatable enclosure having an interior side and an exterior side. The primary inflatable enclosure includes a mouth opening and a central cavity. The primary inflatable enclosure is adapted for connection to an inflation mechanism at the mouth opening. At least one inflatable and transferable gas vent is connected directly or indirectly to the primary inflatable enclosure. The inflatable gas vent is transferable between an open venting position and a closed non-venting position. A tether is provided, the tether being at least partially located within the central cavity of the primary inflatable enclosure. The tether is connected both to the inflatable gas vent and also to the inflatable enclosure. In one embodiment of the invention, the tether is configured for transfer of the vent from an open venting position to a closed non-venting position. In at least one embodiment, the vent in the open venting position is positioned substantially on the exterior side of the primary inflatable enclosure. In some embodiments, the airbag is provided with two of such gas vents, one on each side. The vent in the closed non-venting position may be positioned substantially on the interior side of the primary inflatable enclosure, in one embodiment of the invention. When the gas vent is in the closed position, there is substantially no gas release from the interior to the exterior of the primary inflatable enclosure, which maximizes the restraint function of the airbag. 
         [0025]    A system for adjusting the force of airbag deployment in real time is provided in the application of the invention. The system includes an inflation mechanism capable of producing inflation gas and a primary inflatable enclosure. The primary inflatable enclosure has an interior side and an exterior side. The primary inflatable enclosure has a mouth opening and a central cavity. The primary inflatable enclosure is connected to the inflation mechanism at the mouth opening. At least one inflatable and transferable gas vent is connected to the primary inflatable enclosure, the gas vent being transferable between an open venting position, and a closed non-venting position. 
         [0026]    A tether is at least partially located within the central cavity of the primary inflatable enclosure, the tether being connected both to the vent and also to the inflatable enclosure. Upon activation of the inflation mechanism, the amount of inflation of the primary inflatable enclosure depends upon the amount of displacement of the leading edge of the primary inflatable enclosure during inflation. A large displacement (as when there is no OOP passenger or no obstruction) will cause the tether to transfer the inflatable and transferable vent to the closed non-venting position. This facilitates maximum force deployment of the airbag. The maximum inflation of the primary inflation enclosure is facilitated by movement of the adjustable gas vent from an open venting position to a closed non-venting position, the movement being facilitated by tension applied to transfer the vent with the tether that is part of this system. 
         [0027]    In some applications during the activation of the inflation mechanism an OOP passenger in undesirable close proximity to the primary inflatable enclosure is contacted by the primary inflatable enclosure at an early stage of inflation. When that occurs, such contact results in minimal displacement forward of the leading edge of the airbag, and therefore results in maintenance of the inflatable and transferable gas vent in the open venting position during the inflation event. This reduces the volume of gas in the primary inflatable enclosure by gas venting through the adjustable gas vent. The force of deployment of the primary inflatable enclosure upon the passenger is reduced in that instance. 
         [0028]    In one aspect of the invention, a method for deploying an airbag against a seat occupant is provided. In the method, an inflation mechanism capable of producing inflation gas is provided. A primary inflatable enclosure having an interior side and an exterior side is disclosed. The primary inflatable enclosure has a mouth opening and a central cavity on the interior side. The primary inflatable enclosure is connected to the inflation mechanism at the mouth opening. At least one inflatable vent is provided that is transferable between an open venting position and a closed non-venting position. A tether also is provided, the tether being at least partially located within the central cavity of the primary inflatable enclosure. The tether is connected to the adjustable vent and to the inflatable enclosure and configured for transfer of the adjustable vent. Upon activation of the inflation mechanism, gas is forced into the primary inflatable enclosure. This causes a rapid advancement of the primary inflatable enclosure. If the primary inflatable enclosure encounters an out of position seat occupant, then advancement of the tether is inhibited. In that instance, then the inflatable vent is not transferred, so that the inflatable vent remains in the open venting position. This minimizes the force of deployment of the airbag against an out of position seat occupant. 
         [0029]    If the primary inflatable enclosure does not encounter an out of position seat occupant, there is full advancement of the leading edge of the airbag. In that instance, there is full advancement of the tether which is connected to the leading edge of the airbag enclosure. Thus, the tether applies a tension force to the inflatable vent, thereby pulling and transferring the adjustable vent to the closed non-venting position. The inflatable vent is pulled by the advanced tether into a closed non-venting position located substantially on the interior side of the enclosure. This maximizes the deployment of the airbag against a seat occupant. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0030]    The details of the invention may be appreciated by reference to the Figures. The Figures are provided for illustration of one or more embodiments of the invention, but it should be recognized that the invention may be practiced in other ways that are not specifically shown or illustrated in the Figures, but such embodiments still are within the spirit and scope of the invention. 
         [0031]      FIG. 1  shows a passenger in an upright seat-belted passenger position  24 . Passenger  10  is restrained by seat belt  16  into seat back  12  and seat base  14 . Inflation mechanism  18  is in the dashboard  22 , and configured for operation with airbag  20 . Sensors (not shown) detect a collision, and relay signals to the inflation mechanism  18 , causing activation and release of gas  38 . 
         [0032]      FIG. 2  illustrates a later time in deployment of the unobstructed airbag, in which the airbag has fully deployed following a collision. The airbag  20  is not obstructed during the initial phase of deployment, as further shown in  FIG. 2 , in which the primary inflatable enclosure  26  is fully advanced into the passenger compartment of the vehicle, due to release of gas  38  from the inflation mechanism  18 . Central cavity  73  of the airbag  20  is shown. 
         [0033]      FIG. 2  shows a point in time just before the passenger has begun moving forward into the inflated airbag  20 , when gas is emerging from standard (non-adjustable) vent  35 . The inflatable gas vent  32   a  in this example has moved from an open venting position to a closed non-venting position, resulting in full force airbag deployment. This occurs by the airbag moving beyond the length of internal tether  50   a  (See  FIGS. 7-8 ). 
         [0034]      FIG. 3  represents a very different set of circumstances compared to  FIGS. 1-2  and  7 - 8 . In the example of  FIG. 3 , an obstruction of an out of position passenger  10  (OOP) has his or her upper body and head  44  undesirably near the dashboard or steering wheel at the time of collision. 
         [0035]    This out of position passenger could occur for many reasons. For example, a passenger  10  could be leaning over and adjusting the radio (distracted) at the moment of impact. Alternately, the passenger  10  (if driving) could have become unconscious due to heart attack or other medical problem, slumping against the steering wheel or dashboard  22 . The passenger could be trying to retrieve something located on the floor of the vehicle. In another instance, an extremely short passenger  10 , with the seat base  14  pulled all the way forward in the automobile could be sitting too close to the dashboard  22 . Another circumstance or example of this type is that an unbelted child may be hovering near or upon the dashboard  22  at the moment of collision. There are many possibilities for an OOP passenger situation. In general,  FIG. 3  illustrates the situation in which a passenger  10  for whatever reason is located undesirably close to the airbag primary inflatable enclosure  26  at the moment of impact. 
         [0036]    In  FIG. 3 , the inflation mechanism  18  is forcing gas into the primary inflatable enclosure  26  at a rapid rate, and the leading edge  42  is actually undesirably exploding into the head  44  of passenger  10 . This could cause serious injury if the full amount of gas pressure from inflation mechanism  18  was not released outside the airbag before maximum deployment. This invention is designed to reduce the force of airbag impact in this out of position passenger circumstance, and the central cavity  73  will not enlarge to full size. 
         [0037]    The manner of reducing the force of impact in the situation of  FIG. 3  is described herein. Inflatable gas vent  32   a  is in the open venting position. The vent  32   a  is in the open position because the leading edge  42  has not moved as far as it would in normal unobstructed deployment. The effect of the inflatable gas vent  32   a  remaining open during deployment is to vent early in the deployment process a large additional amount of gas that otherwise would contribute to maximum deployment. This venting is in addition to the conventional venting that occurs through standard vent  35 . It should be noted that in a typical embodiment of this invention, there are inflatable gas vents and also conventional standard vents on each side of the airbag (see  FIGS. 7-8  herein). The net result is that large amounts of explosive gases are vented to the exterior side of the primary inflatable enclosure  26  of the airbag  20 , which substantially reduces the force of impact. The added venting through inflatable gas vent  32   a  reduces substantially the force of impact upon passenger  10 . That is, the leading edge  42  of airbag  20  impacts more softly into the head  44  of the out of position passenger  10 , due to extra gas venting through adjustable gas vent  32   a  and  32   b  (seen in  FIG. 8 ). 
         [0038]    One advantage of this manner of reducing airbag force is that the mechanism of action is dynamically controlled. In this situation, the error rate of incorrect airbag deployment is reduced, since there are no electronic signals necessary to reduce in real time the force of impact in the out of position occupant situation. Any other mechanism (as in the prior art) that relies upon signals or sensing of electronic signals is inherently less reliable than a dynamic system of the invention. 
         [0039]      FIG. 4  shows a partial cross-section of an inflatable gas vent  32   a  of the invention in the open venting position. Tether  50   a  of a predetermined length is attached to inflatable gas vent  32   a . Folds  54   b  and  54   a  are seen, which contain vent holes  46   a  and  46   b.    
         [0040]      FIG. 5  reveals the transfer of an inflatable and transferable gas vent  32   a  (as in  FIG. 4 ) from an open venting position to a closed non-venting position. This occurs by of the movement of the leading edge  42  beyond the range (length) of tether  50   a , which results in the leading edge of the airbag primary inflatable enclosure  26  moving beyond the vent  32   a , pulling the vent  32   a  from the exterior of the primary inflatable enclosure  26  to the interior. 
         [0041]      FIG. 6  illustrates the final stage of inflatable vent  32   a  transfer. This results in substantial closure of the inflatable gas vent  32   a .  FIG. 6A  illustrates one potential embodiment of the adjustable gas vent  32   a , in which folds  54   a - d  contain, respectively, vent holes  46   a - d  (See  FIGS. 6A-6B ). Although this embodiment shows a four fold arrangement, it is recognized that any number of such folds or sides could be employed, including two, three, and five, six, seven, eight, nine, ten, or more. Any geometry that works well in manufacturing operations could be employed to vent the gas.  FIG. 6B  shows another embodiment of the inflatable gas vent, in which folds  70   a - d  are separated by vent holes  71   a - d , located between the folds. 
         [0042]      FIG. 7  illustrates a top view of an early stage deployment similar to that shown in  FIGS. 1-2 , wherein the leading edge of the unobstructed airbag  20  is applying tension to the tethers  50   a  and  50   b , which pulls on the inflatable gas vents  32   a - b . In this deployment, there is no out of position occupant or passenger (similar to that shown in  FIGS. 1-2 ).  FIG. 8  shows the situation of  FIG. 7  at a later point in time. Inflatable gas vents  32   a - b  are closed due to the advancement of leading edge  42  of airbag  20  beyond the inflatable gas vents  32   a - b . Conventional airbag vents  35 - 36  are shown as well, which release gas from central cavity  73 . This results in change in location of the inflatable gas vents  32   a - b , from the exterior side to the interior side of the primary inflatable enclosure  26 . This results in closure of the inflatable gas vents  32   a - b , which eliminates gas escape from the inflatable gas vents  32   a - b , which maximizes airbag force for the collision protection of the normally seated occupant. 
         [0043]      FIG. 8  shows the situation of  FIG. 7  at a later point in time, in which the tethers have pulled the gas vents from the exterior side to the interior side of the primary inflatable enclosure, resulting in closure of the gas vents. 
         [0044]      FIG. 9A  (cross-sectional view along  9 A- 9 A of  FIG. 9B ) reveals an alternate embodiment of the invention, with an alternate configuration for the venting structure, gas vent  100 . Tether  101  is sewn or otherwise attached at tether attachment point  102  to the walls  103 , 104  of the gas vent  100 . The gas vent  100  is attached to primary inflatable enclosure  105  at attachment points  106 ,  107 . Inflation gases pass along the direction of the arrows during venting. 
         [0045]      FIG. 9B  is a top view of the device shown in  FIG. 9A .  FIG. 9C  shows a perspective view of the gas vent  100  of  FIGS. 9A-9B , showing seams  106  and  107 .  FIG. 9D  shows the gas vent  100  in the pulled through and closed configuration. 
         [0046]      FIGS. 10A-10E  show an alternate embodiment of a gas vent  110 , constructed from blank  111 . A hole  112  is shown with fold line  113 . When the blank  111  is folded, it may be attached to airbag wall  114 , and closed with stitches  115  to form vent  110 . Tether  118  is sewn at point  117 .  FIG. 10C  shows a top view looking down into the top of the vent  110 . Air flows along the direction of arrows shown.  FIG. 10D  shows a cross sectional view taken along lines  10 D- 10 D of  FIG. 10C .  FIG. 10E  shows the vent  110  in the closed position, pulled through and beyond the airbag wall  114 . 
         [0047]      FIGS. 11A-E  show an alternate and additional embodiment of a gas vent  120  made from blank  123 . The blank  123  contains fold line  122 , across whole  121 . Tether  124  is stitched to blank  123  at point  125 . Blank  124  is stitched to airbag side wall  126 .  FIG. 11E  shows the closed position of gas vent  120 , which is pulled beyond the side wall  126 . 
         [0048]      FIGS. 12A-E  show an alternate and additional embodiment of a gas vent  130  made from blank  133 . The blank  133  contains fold line  132 , across whole  131 . Tether  134  is stitched to blank  133  at point  135 .  FIG. 12D  shows a cross sectional view taken along lines  12 D- 12 D shown in  FIG. 12C . Blank  134  is stitched to airbag side wall  136 .  FIG. 12E  shows the closed position of gas vent  130 . 
         [0049]    The invention is further shown and described by the appended claims.