Abstract:
An inflatable restraint apparatus provides deployment in a very short duration while at the same time controlling and decelerating the moving parts upon deployment. The apparatus includes an interior panel and an airbag deployment door formed in the interior panel and designed to break free from the panel upon deployment of the airbag. An airbag chute is suitably supported behind the employment door and directs deployment of the airbag outwardly towards the deployment door. A metal hinge connects the airbag chute and the deployment door, and is structured to control and decelerate the door during deployment.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to an inflatable restraint apparatus for an automotive vehicle, and more particularly relates to controlled opening of the apparatus upon deployment of an airbag.  
       BACKGROUND OF THE INVENTION  
       [0002]     Most modern vehicles include inflatable restraint apparatus having deployable airbags positioned in many locations throughout an automotive vehicle. Generally, an interior panel includes a deployment door formed into the panel which is designed to break free upon deployment of the airbag. A supporting structure behind the interior panel typically contain flexible tethers or metal hinges, which in combination with the deployment door are designed to let the airbag deploy in a very short duration.  
         [0003]     Unfortunately, these inflatable restraint apparatus are subjected to often conflicting requirements. A primary aim of the apparatus is to deploy the airbag very quickly. At the same time, it is desirable to control the opening of the deployment door to avoid break explosion and the possibility of flying parts. Accordingly, there exists a need to provide an inflatable restraint apparatus which permits deployment of the airbag in a very short duration, while at the same time allowing for control and deceleration of the deployment door.  
       BRIEF SUMMARY OF THE INVENTION  
       [0004]     The present invention provides an inflatable restraint apparatus having a deployable airbag which provides deployment in a very short duration while at the same time controlling and decelerating the moving parts upon deployment. The apparatus includes an interior panel and an airbag deployment door formed in the interior panel and designed to break free from the panel upon deployment of the airbag. An airbag chute is suitably supported behind the employment door and directs deployment of the airbag outwardly towards the deployment door. A metal hinge connects the airbag chute and the deployment door, and is structured to control and decelerate the door during deployment.  
         [0005]     The hinge has a first transition area and a second transition area independent of one another. The first transition area interconnects a first hinge portion and a second hinge portion, while the second transition area interconnects the second hinge portion and a third hinge portion. The first hinge portion is connected to the deployment door. The first transition area is structured to promote rotation of the first hinge portion relative to the second hinge portion, while the second transition area is structured to promote outward translation of the second hinge portion relative to the third hinge portion. Thus, the deployment door first moves outwardly and then rotates upon deployment of the airbag.  
         [0006]     According to more detailed aspects, the second transition area comprises a wave structure formed into the metal hinge. The wage structure is drawn out upon deployment of the airbag to promote outward translation of the second hinge portion and deployment door. In an alternate embodiment, the second transition area comprises a rivet and a slot structure formed into the second and third hinge portions, which also allows outward movement of the second hinge portion and deployment door.  
         [0007]     According to even further details, a corner plate is attached to the metal hinge proximate the first transition area. The corner plate is designed to limit rotation of the first hinge portion relative to the second hinge portion. In particular, the corner plate breaks the rotation of the deployment door and provides resistance relative to the hinge. The corner plate decelerates the rotation of the deployment door, but provides quick opening in the outward or Z-direction. Preferably, the corner plate is attached to the second hinge portion and overlies the first transition area. The corner plate may be designed to limit rotation of the deployment door to a position where the deployment door cannot reach a window panel of the vehicle, such as a windshield. The thickness of the corner plate as well as the formation of bulldozer tabs can be used to adjust the amount of resistance provided by the corner plate. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention. In the drawings:  
         [0009]      FIG. 1  is a cross-sectional view, taken from the side, of an inflatable restraint apparatus constructed in accordance with the teachings of the present invention;  
         [0010]      FIG. 2  is a side view similar to  FIG. 1  but showing the initial outward opening of the apparatus;  
         [0011]      FIG. 3  is an enlarged cross-sectional view, partially cut-away, showing the hinge forming a portion of the inflatable restraint apparatus depicted in  FIG. 1 ;  
         [0012]      FIG. 4  is an enlarged cross-sectional view, partially cut-away, similar to  FIG. 3  but showing an alternate embodiment of the hinged structure;  
         [0013]      FIG. 5  is a cross-sectional view similar to  FIGS. 1 and 2  but showing the middle stage of opening of the apparatus;  
         [0014]      FIG. 6  is an enlarged perspective view of the corner plate forming a portion of the inflatable restraint apparatus depicted in  FIG. 1 ; and  
         [0015]      FIG. 7  is a cross-sectional view of the inflatable restraint apparatus depicted in  FIG. 1 , but showing the last stage of opening of the apparatus. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0016]     Turning now to the figures,  FIG. 1  depicts a cross-sectional view of an inflatable restraint apparatus  20  having an airbag  10  and constructed in accordance with the teachings of the present invention. The apparatus  20  generally includes an interior panel  22  such as an instrument panel, door panel or the like. The interior panel  22  includes an airbag deployment door  24  formed in the interior panel  22  and defined by one or more pre-weakened peripherical lines  26 . The deployment door  24  is designed to break free from the interior panel  22  at the pre-weakened line  26  upon deployment of the airbag  10 , as is known in the art.  
         [0017]     An airbag mechanism  30  (having the airbag  10 ) includes an airbag chute  32  suitably supported behind and assembled with the interior panel  22 , and specifically behind the deployment door  24 . The airbag chute  32  generally includes a peripherical side wall  36  directing deployment of the airbag  10  outwardly through the chute  32 . Flanges  34  are positioned proximate the interior panel  22  and may be attached thereto. An airbag cover  38  is connected to the deployment door  24 , preferably by welding, although other connection mechanisms may be used.  
         [0018]     A metal hinge  40  is used to connect the deployment door  34  to the airbag chute  32 . Generally, the hinge  40  comprises a first portion  42 , a second portion  44  and a third portion  46 . The first hinge portion  42  is embedded within the airbag cover  38 , or is otherwise suitably connected to the deployment door  24 . The second hinge portion  44  extends parallel to the airbag  10  and to the lateral wall  36  of the airbag chute  32 , while also being positioned inside the airbag chute  32 . The third hinge portion  46  is suitably connected to the airbag suite  32 . A first transition area  48  interconnects the first and second portions  42 ,  44  of the hinge  40 , while a second transition area  50  interconnects the second and third portions  44 ,  46  of the metal hinge  40 . The first transition area  48  is generally S-shaped (or 2-shaped) to promote rotation of the first hinge portion  42  relative to the second hinge portion  44 . Thus, the first transition area  48  permits rotation of the deployment door  24  relative to the airbag chute  32 . The second transition area  50  is structured to promote outward translation of the second hinge portion  44  relative to the third hinge portion  46 . The second hinge portion  44  extends parallel to the airbag  10  and to the lateral wall  36  of the airbag chute  32 , while also being positioned inside the airbag chute  32 .  
         [0019]     As best seen in  FIG. 3 , the second transition area  50  of the metal hinge  40  is positioned rearwardly from the first transition area  48  and includes a wave structure defined by a predetermined number of crests  52  connected by troughs  54 . The crests  52  are angled laterally away from the chute  32  and preferably inwardly away from the deployment door  24 . As will be seen with further reference to  FIG. 2 , upon deployment of the airbag  10 , the second transition area  50  guides the opening of the deployment door  24  outwardly to provide a clean separation from the interior panel  22 . That is, the wave structure  52 ,  54  is drawn out as shown in  FIG. 2 , such that the second transition area  50  extends along the side wall  36  of the airbag chute  32 . In this way, the side wall  36  also guides the drawing out of the waves in conjunction with the second transition area  50 .  
         [0020]     An alternate embodiment of the second transition area  50  has been shown in  FIG. 4  and is denoted as  50 ′. In the figure, the second transition area  50 ′ is comprised of multiple rivets  72  and slots  74 . The rivets  72  are suitably connected to the second hinge portion  44 , while the slots  74  are formed in the third hinge portion  46 . It will be recognized that these working parts could be interchanged. The slots  74  are designed to cooperate with the rivets  72  to permit translation of the second hinge portion  44  outwardly relative to the third hinge portion  46 . Thus, the second transition area  50 ′, like the prior embodiment, permits outward movement of the deployment door  24 . Although two embodiments for the second transition area  50 ,  50 ′ have been shown in  FIGS. 3 and 4 , it will be recognized by those skilled in the art that numerous other structures can be employed to provide translation of the second hinge portion  44  relative to the third hinge portion  46 .  
         [0021]     Once the deployment door  24  has begun moving outwardly (as indicated by the arrow  70  in  FIGS. 3 and 4 ) the door  24  will also begin to rotate as is shown in  FIG. 5 . That is, the first transition area  48  of the metal hinge  40  promotes rotation of the first hinge portion  42  relative to the second hinge portion  44 , and hence rotation of the deployment door  24  and airbag cover  38 . In order to regulate the rotation of the deployment door  24 , the inflatable restraint apparatus  20  includes a corner plate  56  which provides a braking function to the rotation.  
         [0022]     As best seen in  FIG. 6 , the corner plate  56  includes a first plate portion  58  connected to a second plate portion  60 . The first and second plate portions  58 ,  60  are disposed at an angle relative to one another and generally an angle substantially corresponding to an angle between the first hinge portion  42  and the second hinge portion  44 , or alternatively the angle between the deployment door  24  and the airbag chute  32 . The first and second plate portions  58 ,  60  are separated by a pivot line  80  which extends along the length of the corner plate  56 . Additionally, bulldozer tabs  76  have been formed into the corner plate  56 , and specifically the second plate portion  60  as shown in  FIG. 6 . The size and location of the bulldozer tabs  76 , as well as the thickness of the corner plate  56 , is selected so as to provide the requisite braking force.  
         [0023]     As seen in  FIGS. 1 and 2 , the second hinge portion  44  includes a first section  62  and a second section  64 . The first section  62  is parallel to the second section  64  and the airbag chute  32 , but is spaced away therefrom to provide room for receiving the corner plate  56 . The second plate portion  60  of the corner plate  56  is connected to the second hinge portion  44  by any suitable method such as welding. The first plate portion  58  is positioned to overlie the first transition area  48  of the metal hinge  40 . The first plate portion  58  is not connected to the first transition area  48  or the first hinge portion  42 , although this could be done (with or without disconnecting the first plate portion  58  from the second hinge portion  44 ) in accordance with the teachings of the present invention. In either case, the first plate portion  58  is positioned to engage the first transition area  48  to restrict the rotation of the first hinge portion  42  relative to the second hinge portion  44 . That is, the corner plate  56  provides resistance relative to the hinge  40  and to the rotation of the first hinge portion  42  relative to the second hinge portion  44 . In this manner, the corner plate  56  decelerates the rotation of the deployment door  24 .  
         [0024]     It will also been seen in  FIG. 5  that the corner plate  56  moves outwardly with the metal hinge  40  as the second hinge portion  44  translates outwardly relative to the third hinge portion  46 . As also seen in the figure, the second hinge portion  44  translates outwardly a predetermined distance corresponding to locating the pivot line  80  of the corner plate  56  in alignment with the interior panel  22 . When the interior panel  22  is an instrument panel, the corner plate  56  is preferably structured to prevent the deployment door  24  and airbag cover  38  from contacting a windshield  12  of the vehicle, as is shown in  FIG. 7 , or from contacting another portion of the interior panel  22 . It will also be seen in  FIG. 7  that the first plate portion  58  has been rotated to a position generally parallel with the second plate portion  60 , although more or less rotation is encompassed by the present invention. Further, the first transition area  48  has also been flattened during rotation of the deployment door  24 .  
         [0025]     Accordingly, it will be recognized by those skilled in the art that the inflatable restraint apparatus of the present invention provides deployment of an airbag in a manner which not only facilitates very short deployment time, but which also controls the deployment such that the door first moves outwardly and then rotates in a controlled manner. Further, the corner plate provides a braking function to the rotation of the deployment door to provide controlled movement and to prevent unwanted contact between the deployment door and other objects within the vehicle.  
         [0026]     The foregoing description of various embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Numerous modifications or variations are possible in light of the above teachings. The embodiments discussed were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.