Abstract:
An inflatable restraint assembly includes an air bag door and chute. The air bag door includes at least one fastener integrally-formed with the air bag door. The chute is adapted to receive the at least one fastener to effect an interlock for retaining the air bag door to the chute. A method for manufacturing the inflatable restraint assembly is also disclosed. A method for assembling the inflatable restraint assembly is also disclosed.

Description:
TECHNICAL FIELD 
   The present invention generally relates to inflatable restraints. More particularly, the invention relates to an inflatable restraint assembly including an air bag door and chute. 
   BACKGROUND 
   In automotive vehicles, an inflatable restraint is typically located behind an instrument panel. Upon being discharged, the inflatable restraint, which is commonly referred to as an air bag, is directed through a chute and into the passenger compartment through an opening formed in the instrument panel. As seen in  FIGS. 6 and 7 , it is known in the art that the opening of an inflatable restraint assembly  1  may comprise a door  2  including a panel  3 , chute periphery  4 , and chute surround  5 . Referring to  FIG. 7 , the chute periphery  4  is fastened to the panel  3  by at least one fastener  6 , which results in a four-piece inflatable restraint assembly  1 . The fastener  6  may be a screw, rivet, heatstake, or the like. If a heatstake, the fastener  6  is welded via any desirable technique, such as, for example, ultrasonic welding. 
   Although adequate for most applications, the inflatable restraint assembly  1  requires at least four parts (i.e. the panel  3 , the chute periphery  4 , the chute surround  5 , and the fastener  6 ). Additionally, the conventional assembly  1  may include dissimilar materials, such as a thermoplastic resin for the chute periphery  4  and steel for the panel  3  and chute surround  5 , which may increase manufacturing complexities. Even further, a secondary fastening operation, such as the fastening of the chute periphery  4  to the panel  3  via the fastener  6  may be required as well. As such, a need exists for an improved inflatable restraint assembly  1  that reduces the number parts, materials, and manufacturing operations. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present disclosure will now be described, by way of example, with reference to the accompanying drawings, in which: 
       FIG. 1  is a front perspective view of an inflatable restraint assembly comprising an airbag door and a chute according to an embodiment; 
       FIG. 2  is a cross-sectional perspective view of the inflatable restraint assembly, taken along line  2 - 2  of  FIG. 1 ; 
       FIG. 3  is a cross-sectional view of the inflatable restraint assembly taken line  3 - 3  of  FIG. 1 ; 
       FIG. 4A  is a front perspective view of the chute shown in  FIG. 1 ; 
       FIG. 4B  is a rear perspective view of the air bag door shown in  FIG. 1 ; 
       FIG. 5A  is a front perspective view of a chute according to an embodiment; 
       FIG. 5B  is a rear perspective view of an air bag door according to an embodiment; 
       FIG. 6  is a front perspective view of a conventional inflatable restraint assembly; and 
       FIG. 7  is a cross-sectional view of the inflatable restraint taken along line  7 - 7  of  FIG. 6 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   The above described disadvantages are overcome and a number of advantages are realized by an inflatable restraint assembly, which is seen generally at  10  in  FIGS. 1-3 . According to an embodiment, the inflatable restraint assembly  10  comprises a similar material and is molded by a mold tool. According to another aspect of the embodiment, a two-piece inflatable restraint assembly  10  is realized. According to yet another aspect of the embodiment, an interlocking feature is realized by the inflatable restraint assembly  10  that eliminates secondary fastening operations and fastening equipment. 
   As illustrated, the two-piece inflatable restraint assembly  10  includes a chute  12  ( FIG. 4A ) and an air bag door  14  ( FIG. 4B ). The air bag door  14  includes a hinge, which is seen generally at  16  in  FIG. 1 , that includes bridge sections  18  and openings  20 . As seen in  FIGS. 2 and 3 , the door  14  includes at least one integrally-formed fastener  22  that extends substantially perpendicularly away from an inboard surface  25  of the door  14 . In the illustrated embodiment, the fastener  22  comprises a snap tab  22  that includes a notched section  24  and a ramped end  26 . It will be appreciated that the integrally-formed fastener  22  can be in the form of any shape to effect an interlock between the air bag door  14  and the chute  12 . 
   To assemble the inflatable restraint assembly  10 , the snap tabs  22  are inserted into respective snap tab passages  28  that are formed in a recessed upper perimeter  30  of the chute  12 . An outboard perimeter  32  of the chute  12  includes at least one rib  34  that is aligned with each of the respective snap tab passages  28 . As a result, upon inserting snap tabs  22  into the snap tab passages  28 , the ramped end  26  flexes away from the ribs  34  in the direction of the arrow, A, and, upon passing the ramped end  26 , the snap tab  22  flexes in the reverse direction of the arrow, A, such that the rib  34  is located into the notched section  24  of the snap tab  22 . As a result, the chute  14  frictionally engages the door  12 , thereby creating an interlocked inflatable restraint assembly  10  to retain the door  12  to the chute  14 . 
   It will be appreciated that the invention is not limited by the type of interlocking mechanism to retain the door  12  to the chute  14 . For example, according to another embodiment of the invention, as seen in  FIGS. 5A and 5B , the inflatable restraint assembly may include pairs of Christmas tree-type fasteners  122  extending from the air bag door  104  that correspond to pairs of passages  128  located in a chute  102 . Although four snap tabs  22  and corresponding snap tab passages  28  are illustrated in  FIGS. 4A ,  4 B and although eight fasteners  122  and corresponding passages  128  are illustrated in  FIGS. 5A ,  5 B, the inflatable restraint assembly  10  may include any desirable number of snap tabs/fasteners  22 ,  122  and corresponding passages  28 ,  128  having any desirable shape to properly retain the door  12  to the chute  14 . 
   Upon interlocking the inflatable restraint assembly  10  as described above, peripheral lip portions  36 ,  136  of the door  14 ,  104  are positioned in a same plane of a chute lip perimeter  38 ,  138  and chute lip tabs  40 ,  140 . Then, the rear-side of the peripheral lip portions  36 ,  136  and chute lip perimeter  38 ,  138  may be affixed to an instrument panel (not shown) using any desirable technique. For example, the peripheral lip portions  36 ,  136  and chute lip perimeter  38 ,  138  may be vibration welded to the instrument panel. If the chute  12  and the door  14  are affixed in such a technique by vibration welding, it is desirable that the material composition of the chute  12  and door  14  be of a similar material as the instrument panel, such as, for example, thermoplastic olefin (TPO). Other suitable materials for the chute  12  and door  14  may comprise nylon, glass fiber reinforced polypropylene (PP), or the like. 
   As described above, an improved inflatable restraint assembly  10  reduces the number parts by providing a two-piece assembly rather than a three-piece assembly that is fastened together by a separate fastener. Thus, because the use of a separate fastener is eliminated, an additional manufacturing operation is eliminated. Even further, the number of materials used to form the inflatable restraint assembly is reduced by molding the chute  12 ,  102  and door  14 ,  104  from a similar material. When formed of a similar material, the chute  12 ,  102  and door  14 ,  104  may be formed in a simplified manufacturing operation by using the same mold tool. 
   The present invention has been described with reference to certain exemplary embodiments thereof. However, it will be readily apparent to those skilled in the art that it is possible to embody the invention in specific forms other than those of the exemplary embodiments described above. This may be done without departing from the spirit of the invention. The exemplary embodiments are merely illustrative and should not be considered restrictive in any way. The scope of the invention is defined by the appended claims and their equivalents, rather than by the preceding description.