Abstract:
An air bag system that includes an energy absorption bracket attaching the air bag to the vehicle body is provided. The energy absorption bracket includes a generally planar surface for attachment of the air bag module thereto. The bracket also includes at least two downstanding legs that interconnect the generally planar surface and the vehicle body. By use of these downstanding legs the bracket forms a space between the air bag and the vehicle body whereby if an object strikes the air bag, the bracket with deform and collapse into said space thereby, absorbing the impact energy from the object.

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates in general to motor vehicle safety systems. More particularly, the present invention relates to an airbag apparatus for motor vehicles. More specifically, but without restriction to the particular embodiment and/or use which is shown and described for purposes of illustration, the present invention relates to an airbag apparatus that includes an impact absorbing mechanism. 
     2. Discussion 
     Automobiles have incorporated many safety systems into their design over the years to help protect the occupants during various types of collisions. The seatbelt, which keeps occupants securely fastened to their seat, was and arguably still is the most prevalent safety device in the industry. 
     In recent years, both the government and the automotive industry realized the advantages that an inflatable occupant restraint system or airbag system could provide. The drive to develop and implement such a system was so strong that within just a few years almost all vehicles included inflatable occupant restraints that protected occupants during frontal collisions. Soon after the introduction of these frontal airbags, the industry began looking for ways and methods of protection during side collisions. 
     One intuitive response was to incorporate inflatable restraints to enhance the protection of the occupants during a collision from the lateral side of a vehicle. These inflatable restraints for lateral or side collisions have been placed in a number of locations within the vehicle. For example, some vehicles have airbags placed in the side of the vehicle seat whereby during a collision the airbag deploys from the side of the seat and forms against the lateral side of the vehicle interior. Other vehicles have placed airbags in the doors that protect during side collisions. Sometimes, due to packaging constraints, it is preferable to place an airbag in either a pillar or over the door header as disclosed in U.S. Pat. No. 5,791,683 assigned to Toyota Gisei Company Limited. Unfortunately, this leads to a number of problems. Most specifically, vehicle regulations in the United States now require that portions of the vehicle interior above the belt line of the occupants have specific energy absorbing characteristics. This requirement FMVSS 201 has lead automotive companies to place impact countermeasures behind headliners and trim pieces in order to satisfy this energy absorbing requirements. Countermeasures include, but are not limited to, energy absorbing foam and crushable plastic ribs that act to absorb impact energy. 
     It is obviously desirable to have a clear, appointed path for any airbag. This is typically employed by the use of the deployment door that is hinged on one end and is moved out of the way by the force of the airbag. This is the standard practice for frontal airbags disposed within the steering wheel, the instrument panel of the vehicle, and a vehicle door. This standard practice becomes more difficult when airbags are disposed in a pillar over the door header. The &#39;683 patent includes such an airbag and disclosures a garnished trim that opens to allow deployment of the airbag. U.S. Pat. No. 5,540,459 assigned to Ford Motor Company describes another arrangement for a side airbag disposed above the door header. In the &#39;459 patent, the airbag deployment forces the headliner inboard so that the airbag can deploy along the lateral side of the vehicle. Although the arrangements that are disclosed in patents &#39;459 and &#39;683 perform satisfactorily, neither includes impact counter measures in their design. The traditional impact countermeasures have been foam and plastic ribs disposed beneath a decorative cover. However, with the addition of these impact counter measures, like ribs of foam, this becomes much more difficult to provide a clear path for airbag deployment. It is therefore desirable to have an airbag system with impact counter measures that allows for deployment of an airbag in a controlled and predetermined direction. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is the principal objective of the present invention to provide an bag system that includes impact countermeasures, the air bag being employed to protect occupants during certain types of collisions and the impact countermeasures design to absorb energy during impacts therewith. 
     It is another objective of the present invention to provide an energy absorption bracket disposed within an air bag module that will not adversely affect the deployment of the airbag. 
     In one form, the present invention concerns an air bag that is attached to a vehicle body via an energy absorption bracket. The energy absorption bracket includes a generally planar surface for attachment of the air bag module thereto. The bracket also includes at least two downstanding legs that interconnect the generally planar surface and the vehicle body. By use of these downstanding legs the bracket forms a space between the air bag and the vehicle body so that if an object strikes the air bag, the bracket with deform and collapse into said space thereby, absorbing the impact energy from the object. 
     Additional benefits and advantages of the present invention will become apparent to those skilled in the art to which this invention relates from a reading of the subsequent description of the preferred embodiment and the appended claims, taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The drawings, which form an integral part of the specification, are to be written in conjunction therewith, and like reference numerals are employed to designate identical components in various views. 
     FIG. 1 is a perspective view of a vehicle interior showing the passenger side, front seat and associated windows and headliner. 
     FIG. 2 is a cross-sectional view of the preferred embodiment of the present invention along the line  2 — 2  of FIG. 1, with a deployed air bag and corresponding movement of the headliner shown in phantom. 
     FIG. 3 is a cross-sectional view of the preferred embodiment of the present invention along the line  2 — 2  of FIG. 1, showing the energy absorbing bracket after being struck by an object from the interior of the vehicle. 
     FIG. 4 is a cross-sectional view of an alternate embodiment of the present invention shown along the line  2 — 2  of FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An apparatus comprising an air bag system with an energy absorption bracket is provided. In the following description, numerous specific details are set forth in order to provide a more comprehensive description of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without these specific details. In other instances, specific details of well-known features have not been described so as not to obscure the present invention. 
     Referring now to the drawings, FIG. 1 illustrates a perspective view of a vehicle  10 , which includes the airbag system and energy absorption bracket of the present invention. Vehicle  10  includes an interior  12 , which includes among other things, a front passenger seat  14  and instrument panel  16  disposed forward thereof. Vehicle interior  10  also includes a vehicle floor  18  that defines the lowermost boundaries of the vehicle interior  12 . The lateral boundaries of the vehicle interior  12  are formed by a front vehicle door  20  and a front vehicle window  22  that extends upward from vehicle door  20  and can be reversibly translated in a vertical manner. Vehicle interior  12  is bounded on the upwardmost surface by headliner  24  which extends substantially from vehicle window  22  on the right side of the vehicle to the vehicle window (not shown) on left side of the vehicle. It should be appreciated that the left and right sides of the vehicle are substantially identical for purposes of this disclosure. Therefore, only the right side will be described and illustrated in detail. Headliner  24  includes a header portion  26 , which extends in a longitudinal manner and is disposed vertically above front window  22 . 
     Turning to FIG. 2, a cross-sectional view of the preferred embodiment of the present invention is illustrated, wherein the header portion  26  of the headliner  24  is described in detail along cross-sectional line  2 — 2  of FIG.  1 . Vehicle body  28  that includes outer sheet metal  30  and inner sheet metal  32  provides structural support to this region of the vehicle. Outer sheet metal  30  also provides an aesthetic appearance to the exterior of the vehicle. It should be appreciated, although not specifically shown in the drawings of the preferred embodiment of the present invention, that inner sheet metal  32  and outer sheet metal  30  are welded together to form a cross-sectional area  34  that provides the structural support to this area of the vehicle. Inner sheet metal  32  includes various apertures and/or attachment points for numerous articles that can be coupled thereto. 
     Airbag module  36  comprises an air bag  38 , energy absorption bracket  40 , and an encapsulation  42 . The bracket  40  is preferably made of steel rollform and is designed to absorb energy. The air bag  38  is preferably a side air bag that is deployed with less force that a frontal airbag, like those found in steering wheels and instrument panels. The bracket  40  extends longitudinally with the air bag  38 . The bracket includes a generally planar portion  44 , an upper downstanding leg  46 , and a lower downstanding leg  48  that form a hat cross section. Lower downstanding leg  48  includes a flange  49  that extends from its distal end  50  in a direction substantially parallel to the generally planar portion  44 . The upper downstanding leg  46  includes a mounting plate  52  extending from its distal end  54  in a direction also substantially parallel to the generally planar portion  44 . As the mounting plate  52  and flange  49  are placed in contact with the inner sheet metal  32 , a space  56  is formed bounded by the inner sheet metal  32 , generally planar portion  44 , lower downstanding leg  48 , and upper downstanding leg  46 . 
     Flange  49  is adapted to be placed into a recess  60  formed by a projection  62  from the inner sheet metal  32 . When placed therein, downward (arrow  64 ) and lateral (arrow  66 ) movement of the flange  49  is restricted. Mounting plate  52  includes a bore  68  formed therethrough that lines up with an aperture  70  in the inner sheet metal  32  when flange  49  is inserted into recess  60 . A bolt  72  is provided which is inserted through both the bore  68  and aperture  70  to ensure a coupled arrangement between the mounting plate  52  and inner sheet metal  32 . It should be appreciated that a plurality of bores and apertures may be provided along the longitudinal length of the air bag module  36  and that projection  62  need not be formed continuously in the longitudinal direction, one or several localized projections  62  would be sufficient. It should further be appreciated that longitudinal locating elements may be added to ensure accurate placement of the air bag module  36 , these longitudinal locating elements could be in the form of slots, pins, or a variety of other structures. 
     The air bag  38  and portions of the energy absorption bracket  40  are covered with an encapsulation  42 , preferably made from some type of polymer. The encapsulation  42  ensures contact between the air bag  38  and the generally planar portion  44 . The encapsulation  42  also extends along the downstanding legs  46 ,  48  and covers both the front side  80  and back side  82  of both the mounting plate  52  and flange  49 . Covering the back side  82  of the mounting plate  52  and flange  49  with encapsulation  42  acts to prevent any possible vibration or noise between the bracket  40  and the inner sheet metal  32 . Encapsulation  42  also includes a slit or a notch  84  formed on the laterally inward and lower corner of the air bag  38 . As the air bag  38  is deployed, it breaks the encapsulation  42  at notch  84  and deploys downward  64  therefrom as shown in phantom in FIG.  2 . As the air bag  38  is deployed, the header portion  26  of the headliner  24  moves laterally inboard from the force of the air bag  38  effectively allowing air bag  38  to extend down window  22 . During deployment of the air bag  38 , the energy absorbing bracket  40  maintains its structural integrity. The preferred construction of bracket  40  is 1040 steel having a thickness of 0.8 mm in the shape described previously. 
     Now in reference FIG. 3, the air bag module  36  after being struck by an object traveling from the interior  12  of the vehicle  10  is illustrated. The object  90  first encounters the headliner  24 , the headliner then imparts force on the air bag module  36 . The energy absorbing bracket  40  with its unique design deforms in a manner shown in FIG. 3 thereby absorbing energy. The bracket  40  deforms and collapses into space  56 . The actual deformation that occurs depends on the object and the angle of impact, but essentially, the downstanding legs  46 ,  48  bend while the generally planar portion  44  encroaches on space  56 . 
     An alternate embodiment of the present invention is shown in FIG.  4 . The energy absorbing bracket  40  includes a lower downstanding leg  48  in the shape of a half pipe  92 , the free end  94  of which is inserted into a recess  96  formed by a projection  98 . This insertion limits upward and lateral movement of the air bag module  36 . The alternate embodiments also includes a raised platform  100  formed within the generally planar portion  44  to aid in the energy absorption characteristics of the bracket. Although the alternate embodiment has some modifications, the energy absorbing bracket  40  does deform and collapse into space  56  thereby absorbing energy, just as in the preferred embodiment. 
     The foregoing description constitutes the preferred embodiments devised by the inventors for practicing the invention. It is apparent, however, that the invention is susceptible to modification, variation and change that will be obvious to those skilled in the art. Inasmuch as the foregoing description is intended to enable one skilled in the pertinent art to practice the invention, it should not be construed to be limited thereby but should be construed to include such aforementioned obvious variations and be limited only by the proper scope or fair meaning of the accompanying claims.