Abstract:
A trim piece for use within the interior of an automotive vehicle in covering relation to a structural support element with an expansible air bag cushion disposed between the trim piece and the structural support element. The trim piece is of a hingeable character including a relatively soft outer layer in substantially surrounding relation to an embedded deformable structural member such that it may be bent away during deployment of the air bag cushion so as to establish a controlled and substantially reproducible path of egress for the air bag cushion.

Description:
TECHNICAL FIELD  
         [0001]    The present invention relates to a trim piece for use in covering relation over an underlying structural element within a transportation vehicle, and more particularly to a pillar trim piece of hingeable character which facilitates the deployment of an inflatable air bag cushion from beneath the pillar trim piece upon the occurrence of an activating collision or roll-over event.  
         BACKGROUND OF THE INVENTION  
         [0002]    It is well known in motor vehicles to provide an air bag module for protecting a vehicle occupant. It is also known to provide an air bag module including an inflatable restraint cushion and an inflator for generating gas to inflate the cushion upon sensing predetermined vehicle conditions such as deceleration exceeding a certain predetermined value. It is further known to provide air bag modules including inflatable restraint cushions which are deployed from storage positions along the door frame of the vehicle in substantially curtain-like fashion between an occupant to be protected and the side portions of the vehicle so as to provide the occupant with a cushioning restraint during side impact or extended roll-over collision events. It is further known to store such curtain-like inflatable cushions at least partially along structural pillar elements extending away from the roof rail of the vehicle and to cover such storage positions with an aesthetic trim piece of substantially trough-like configuration. Such trim pieces are typically formed of relatively hard plastic having an aesthetic surface in color coordination with the interior of the vehicle.  
           [0003]    The deployment of an inflatable air bag cushion from beneath a trim piece requires that the trim piece be forced away from the underlying structural element to permit the exit of the inflatable air bag cushion from its storage position between the trim piece and the structural element. In the past it has been found that such disengagement of the trim piece may be difficult to control due to the substantially rigid character of such plastic trim pieces. Moreover, hard plastic trim pieces may perform differently under different temperature conditions due to differences in flexibility characteristics. In this regard, it may be desirable to avoid the complete fracture of the trim piece during deployment of the inflatable air bag cushion over a broad range of temperatures so as to avoid the generation of loose debris within the vehicle during the latter stages of a collision event.  
         SUMMARY OF THE INVENTION  
         [0004]    This invention offers advantages and alternatives over the prior art by providing a trim piece for use within the interior of an automotive vehicle in covering relation to a structural support element with an expansible air bag cushion disposed between the trim piece and the structural support element. The trim piece is of a hingeable character such that it may be bent away from the underlying structural support element during deployment of the air bag cushion so as to establish a controlled and substantially reproducible path of egress for the air bag cushion.  
           [0005]    According to one potentially preferred aspect of the present invention, these advantages may be accomplished in a trim element which substantially utilizes preexisting trough-like geometries of trim pieces as are presently used in covering relation to structural support pillars.  
           [0006]    According to a further potentially preferred aspect of the present invention, the trim piece may include a relatively soft impact absorbing outer layer of flexible material in substantially surrounding relation to an embedded structural member.  
           [0007]    According to yet a further potentially preferred aspect of the present invention, the trim piece may include a relatively soft outer covering layer in substantially surrounding relation to a stiffening inner structure of metal or the like. The stiffening inner member is preferably of a porous construction so as to permit the relatively soft surface material to permeate across the stiffening inner structure. The stiffening inner structure may include a hinge line of reduced thickness extending in a pattern at least partially along the length of the stiffening inner structure so as to define a living hinge within the trim piece. Integrated attachment structures such as male detent elements may project outward from the stiffening inner structure and through the outer covering layer for engagement with cooperating openings within the underlying structural element. The attachment elements are preferably located within an attachment zone on one side of the hinge line such that the portion of the stiffening inner structure on the other side of the hinge line is substantially freely rotatable away from the underlying structural element.  
           [0008]    This invention provides a trim piece for use in covering a structural support element such as a structural pillar or roof rail of the vehicle frame. The trim piece can be bent away from the structural support element upon the application of a bending moment caused by the inflation and deployment of an air bag cushion housed between the trim piece and the structural support element. The trim piece may nonetheless be held in place at the support element by substantially static attachment points which are not subjected to substantial flexural bending. Prior to deployment of the inflatable air bag cushion, the relatively soft outer covering of the trim piece provides a degree of cushioning to an occupant which may be beneficial in some instances. Accordingly, the present invention is believed to provide useful advantages over the prior art.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    The accompanying drawings, which are incorporated in and which constitute a part of this specification illustrate a potentially preferred embodiment of the present invention and, together with the general description of the invention given above and the detailed description set forth below, serve to explain the principles of the invention wherein:  
         [0010]    [0010]FIG. 1 is a cut-away view of the interior of an automotive vehicle including an inflatable curtain-like air bag cushion stored along a portion of a pillar trim element;  
         [0011]    [0011]FIG. 2 is a view similar to FIG. 1 following deployment of the inflatable curtain-like air bag cushion;  
         [0012]    [0012]FIG. 3 is a perspective view of a pillar trim piece according to the present invention showing in hidden lines a substantially embedded stiffening structural support member;  
         [0013]    [0013]FIG. 4 is a perspective view of a stiffening structural support member for use within the trim piece of FIG. 3;  
         [0014]    [0014]FIG. 5 is a cross-section taken generally along line  5 - 5  in FIG. 4 illustrating the presence of an integrated attachment mechanism;  
         [0015]    [0015]FIG. 6 is a cross-sectional view taken generally along line  6 - 6  in FIG. 3;  
         [0016]    [0016]FIG. 7 is a cross-sectional view taken generally along line  7 - 7  in FIG. 3; and  
         [0017]    [0017]FIG. 8 is a view similar to FIG. 6 illustrating the trim piece in a hinged configuration following deployment of an underlying air bag cushion. 
     
    
       [0018]    While the invention has been illustrated and generally described above and will hereinafter be described in connection with certain potentially preferred embodiments and practices, it is to be understood that in no event is the invention limited to such illustrated and described embodiments and practices. On the contrary, it is intended that the present invention shall extend to all alternatives and modifications as may embrace the general principles of this invention within the true spirit and scope thereof.  
       DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0019]    Turning now to the drawings wherein to the extent possible like reference numerals are utilized to designate like components throughout the various views, in FIG. 1 there is illustrated a vehicle  10  such as an automotive car, truck or the like. The vehicle  10  includes a front seat  12  which may be used to support a front seated occupant  14 . The vehicle  10  may further include a rear seat  16  which may be used to support a rear occupant (not shown). However, it is to be appreciated that the present invention may likewise be utilized in a vehicle incorporating no rear seat as well as in vehicles incorporating three or more rows of seats. In addition, while the present invention will hereinafter be described in connection with use in an automotive vehicle, it is to be appreciated that the present invention may likewise be utilized in other transportation vehicles including by way of example only railroad cars and aircraft.  
         [0020]    In order to provide visibility to the occupants of the vehicle  10 , the vehicle  10  is provided with a windshield  18  as well as with one or more side windows  20 . As shown, the side windows  20  are located generally adjacent to the seats  12 ,  16  to the sides of the occupants seated therein. The windows  20  are preferably bounded along their lateral edges by aesthetic trim elements  22 ,  22 ′,  22 ″ which cover a series of structural pillars extending downwardly from the structural roof rail  26  at the intersection between the roof  28  and the top of the windows  20 . The roof rail  26  may likewise be covered by an aesthetic trim piece if desired.  
         [0021]    As illustrated, it is contemplated that an air bag cushion  30  of substantially curtain-like configuration may be stored in rolled or folded relation along at least a portion of the roof rail  26  and beneath segments of one or more of the aesthetic trim elements  22 ,  22 ′,  22 ″.  
         [0022]    According to the illustrated and potentially preferred practice, the air bag cushion  30  is preferably in fluid communication with a gas discharging inflator  32 . As is well known to those of skill in the art, gas may be discharged from the inflator  32  and into the air bag cushion  30  to effect deployment of the air bag cushion  30 . As illustrated, the inflatable air bag cushion  30  may also be attached to tethering elements  34  disposed beneath aesthetic trim elements  22 ,  22 ″ on either side of the region to be covered by the air bag cushion  30  following deployment.  
         [0023]    Referring now to FIG. 2, the air bag cushion  30  is illustrated in an inflated deployed state substantially covering an area adjacent to the seats  12 ,  16 . While the air bag cushion  30  is illustrated as extending in a deployed state substantially across the entire length of the vehicle interior adjacent to the seats  12 ,  16 , it is likewise contemplated that the air bag cushion  30  may be deployed over a diminished region if desired such as the region between the so-called “A” pillar and the “B” covered respectively by the aesthetic trim elements  22 , and  22 ′ or between the “B” pillar and the “C” pillar covered respectively by the aesthetic trim elements  22 ′ and  22 ″.  
         [0024]    Regardless of the particular configuration or orientation of the air bag cushion  30 , it is contemplated that a path of deployment is required from beneath one or more of the aesthetic trim elements  22 ,  22 ′,  22 ″ as well as from beneath any trim element as may cover the roof rail  26 . That is, since the air bag cushion  30  is initially hidden beneath such trim elements, the inflated deployment of the air bag cushion  30  necessarily requires the air bag cushion  30  to exit from beneath at least portions of overlying aesthetic trim elements. The establishment of the requisite exit paths requires that the overlying trim elements be moved away from the underlying frame structure at the desired exit location.  
         [0025]    A potentially preferred construction for the aesthetic trim elements which facilitates the controlled opening of a deployment path is illustrated in FIG. 3 while the construction for aesthetic trim elements according to the present invention is illustrated and will hereafter be described in relation to the trim element  22  overlying the “A” pillar of the vehicle frame. It is to be understood that the features of such construction are likewise applicable to aesthetic trim elements  22 ′ overlying the “B” pillar and  22 ″″ overlying the “C” pillar respectively as well as any aesthetic trim element overlying the roof rail  26 .  
         [0026]    Referring simultaneously to FIGS.  3 - 7 , an aesthetic trim element  22  in accordance with the present invention preferably includes a stiffening structural support member  40  having an outer covering  44  of relatively soft polymeric material. The structural support member  40  is preferably formed of a substantially rigid material such as metal or the like. While the structural support member  40  may be substantially flat, according to the illustrated and potentially preferred embodiment of the present invention, the structural support member  40  incorporates some degree of curvature across its surface so as to facilitate the establishment of a convex face  43  and a corresponding concave underside  45  across the trim element  22 . As will be appreciated, such a concave underside  45  provides a storage area for the air bag cushion  30  prior to deployment. By way of example only, and not limitation, the structural support member  40  may be formed from stamped aluminum or light gauge steel.  
         [0027]    The outer covering  44  is preferably formed of a substantially flexible soft thermoplastic elastomer such as polyurethane, TPO or the like which is overmolded onto the structural support member  40 . As best illustrated in FIG. 6, this overmolding preferably results in the structural support member  40  being substantially encased within the material forming the outer covering  44 .  
         [0028]    As best seen through reference to FIG. 4, the structural support member  40  preferably includes a number of openings  46  extending between opposing front and rear surfaces of the trim element  22 . The openings  46  provide for flow through passage of the material forming the outer covering  44  across the structural support member  40  so as to promote complete overmolding coverage and secure adhesion of the structural support member  40  within the outer covering  44  (FIG. 7).  
         [0029]    As best seen through reference to FIGS. 4 and 5, the structural support member  40  may include one or more integral outwardly projecting detent members  48  for attachment to the underlying frame structure. As will be appreciated, the location of such detent members  48  establishes a zone of attachment  47  for the trim elements to prevent complete separation away from the underlying support upon deployment of the air bag cushion  30 . As illustrated, the detent members  48  are preferably arranged in spaced relation along the length of the structural support member on one side of an integral hinge  50  which is disposed between the zone of attachment  47  and a displaceable flap portion  51  extending along the desired location of egress for an underlying air bag cushion  30 .  
         [0030]    According to one potentially preferred practice, the hinge  50  is formed by thinning the structural support member  40  in a desired pattern along the length of the structural support member  40 . It is contemplated that such thinning may be either in the form of a substantially continuous groove or may be in the form of intermittent slots of reduced thickness running in the desired pattern. In the event that the material forming the structural support member  40  is sufficiently malleable, it is also contemplated that the desired hinging action may be achieved without the introduction of any preferentially thinned integral hinge  50 . It is also contemplated that the integral detent members  48  may be eliminated and replaced with traditional screws or other fastening devices extending through the structural support member within the desired zone of attachment  47 .  
         [0031]    Due to the presence of the structural support member  40  and the fact that attachment to the underlying support member is carried out within a zone of attachment  47  extending on one side of a hinge line  50  so as to leave a substantially unattached zone corresponding to a displaceable flap portion  51  on the other side of the hinge line  50 , the displaceable flap portion  51  may be bent freely away from the underlying pillar or other support surface upon the introduction of a moment generating force. Thus, by arranging the trim elements of the present invention within the vehicle  10  such that the displaceable flap portions  51  are aligned adjacent to the areas to be covered by the air bag cushion  30 , the inflation of the air bag cushion  30  beneath the trim element gives rise to a moment generating force causing a path of egress to be opened for the inflating air bag cushion  30  as the flap portion  51  is bent away from the underlying frame (FIG. 8).  
         [0032]    The substantially flexible nature of the outer covering  44  permits such bending to take place without potentially undesirable fracture of the outer covering  44 . Moreover, despite the bending away of the flap portion  51 , the trim element is nonetheless maintained in place at the zone of attachment  47  throughout the deployment process. Such continued attachment prevents the potentially undesirable complete displacement of the trim element.  
         [0033]    It is to be understood that while the present invention has been illustrated and described in relation to certain potentially preferred embodiments, constructions, and procedures, that such embodiments, constructions, and procedures are illustrative only and that the present invention is in no event to be limited thereto. Rather, it is contemplated that modifications and variations embodying the principles of this invention will no doubt occur to those of skill in the art. It is thus contemplated and intended that the present invention shall extend to all such modifications and variations as may incorporate the broad aspects of the invention within the full spirit and scope of the appended claims and all equivalents thereto.