Abstract:
A vehicle having and airbag inflator device and method of installation is disclosed. The airbag inflator device is positioned in a recess in a body structure roof rail or enclosed in an interior cavity defined by the roof rail member. The airbag inflator is mounted to the roof rail directly or to a cover plate that when installed forms a part of the roof rail substantially covering an aperture in the roof rail.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention generally pertains to inflatable airbag restraint systems for use in passenger vehicles. 
       BACKGROUND 
       [0002]    Protective airbag restraint systems for use in automotive passenger applications have become standard equipment on almost all new vehicles sold in the United States and are common equipment on vehicles manufactured and sold throughout the world. In recent years, inflatable side curtain airbags positioned along side roof rails above the occupant side doors that extend downward to further protect the occupants have grown in use due to their ability to provide additional protection in these areas. 
         [0003]    It has been a challenge for automotive manufactures to package and conceal the mechanical components of the restraint systems, including the inflatable airbags and the airbag inflator which provides the fluid, typically a gas, to inflate the airbags in the roof rail or A-pillar areas of the sheet metal structure of the vehicle. The airbag restraint system components have typically been concealed from occupant view behind interior trim panel components. In order to provide adequate packaging space for the airbag components, the panels must be relevantly large and naturally protrude into the passenger compartment reducing the amount space for the occupants. 
         [0004]    An airbag restraint system component that is particularly difficult to package and conceal from occupant view is the airbag inflator. The inflator is typically a relatively large and rigid cylindrical canister that must be rigidly attached to the body structure and be positioned to minimize contact by an occupant during an impact event. The packaging and positioning of the inflator canister must not compromise the principal function of providing a sufficient path for the fluid to pass from the canister to the airbag for rapid deployment. 
       SUMMARY 
       [0005]    The present invention is an inflatable restraint system for a passenger vehicle including a vehicle body structure having a roof rail and an inflatable restraint system secured to the body structure. In one example of the invention, the body structure is a roof rail including an outer roof rail and an inner roof rail member. The inner roof rail member includes an inboard facing surface positioned toward the interior of a passenger compartment. 
         [0006]    In an example of the invention, the inner roof rail member includes a first aperture in the inboard facing surface and a separate cover plate which is configured and positioned to substantially cover the first aperture when connected to the inner roof rail member. In this example, the inflator canister is securely attached to the cover plate which is then installed over the first aperture. The cover plate is then securely connected to the inner roof rail member thereby positioning the inflator canister in an interior cavity of the roof rail defined by the inner roof rail and outer roof rail members. In this example, the entire inflator canister is concealed within the roof rail with the possible exception of a gas guide that may extend through the cover plate to place the concealed inflator canister in fluid communication with the inflatable airbag positioned and attached to the inboard facing surface of the inner roof rail member. 
         [0007]    In another example of the invention, the inflatable airbag restraint system includes an inflatable airbag that is connected to the body structure and an inflator in fluid communication with the airbag. The roof rail inner member includes a recess formed in the inner roof rail member extending outward toward the outer roof rail member. At least a portion of the inflator is positioned in the recess to reduce the amount of the remaining inflation canister from extending beyond the inboard facing surface toward the passenger compartment. In one example of the invention having a recess for receipt of at least a portion of the inflator canister, at least 30% of a side profile or diameter of the canister is positioned or concealed within the recess. 
         [0008]    In alternate examples of the invention, the inflator is secured to either the cover plate or the inner roof rail member by a retainer. In one example of the retainer, a retainer strap is used to securely connect the inflator canister to the cover plate forming an integrated inflator assembly. In another example of the retainer, one or more clamps are used to position and secure the inflator canister in the recess. 
         [0009]    Methods of installing the inflator include positioning and securing at least a portion of the inflator either in an interior cavity in the roof rail or in a recess formed in the inner roof rail member. 
         [0010]    Other applications of the present invention will become apparent to those skilled in the art when the following description of the best mode contemplated for practicing the invention is read in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein: 
           [0012]      FIG. 1  is a cut-away perspective view of one example of the invention showing the inflator positioned in an interior cavity behind a cover plate; 
           [0013]      FIG. 2  is a side view of the cut-away perspective view of the invention shown in  FIG. 1 ; 
           [0014]      FIG. 3  is an alternate example of the invention shown in  FIG. 1  having a smaller cover plate; 
           [0015]      FIG. 4  is an alternate example of the invention in  FIG. 1  showing the inflator partially positioned in a recess and including an example of retainers that may be used; 
           [0016]      FIG. 5  is a side view of the invention shown in  FIG. 4 ; and 
           [0017]      FIG. 6  is an alternate example of the invention shown in  FIG. 4  illustrating almost the entire inflator concealed in a recess in the inner roof rail member. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    Referring to  FIGS. 1-6 , examples of an airbag inflator device and methods of installation are illustrated and described below. Referring to  FIG. 1 , an example of an inflator device  10  used in an exemplary application in a passenger vehicle roof rail  14  positioned above a driver&#39;s side door  18  is illustrated. Inflator  10  may be positioned in other locations along the roof rail  14  and in different positions in relation to other structural pillars than as illustrated. 
         [0019]    In  FIG. 1 , the roof rail  14  includes an inner roof rail member  20  and an outer roof rail member  24 . The inner  20  and outer  24  roof rail members are attached to one another along flanges  16  by spot welding, seam welding or other attaching methods known by those skilled in the art. Inner roof rail member  20  includes an inboard facing surface  21  directed toward the interior compartment of a vehicle (not shown). Outer roof rail member  24  includes an outer surface  25  directed toward the exterior of a vehicle (not shown). Inner  20  and outer  24  roof rail members are preferably stamped, cold rolled steel in a suitable shape to fit the particular application in a vehicle. 
         [0020]    In a preferred example, inner roof rail member  20  and outer roof rail  24  form an interior cavity  26  between the members. The size, shape and orientation of interior cavity  26  may vary along the length of the roof rail to suit the particular application. In a preferred example of the invention shown in  FIG. 1 , the inboard facing surface  21  of the inner roof rail member  20  includes a first aperture  30  in communication with interior cavity  26 . As shown in  FIGS. 1 and 2 , an inflatable airbag restraint system is illustrated including an inflator  40  which may include a cylindrically-shaped canister  46 . Canister  46  includes a first end (not shown), a second end  50  and an outer wall  52  generally defining a longitudinal axis  54  along the length of canister  46 . Inflator canister  46  is preferably cylindrical in shape and may be made from steel or aluminum suitable for containment of compressed, high pressure fluid such as a gas. 
         [0021]    In the example of the invention shown in  FIGS. 1 and 2 , a gas guide  56  may be used. Gas guide  56  is preferably a hollow, tubular-shaped member connected to first end  48  of inflator canister  46  permitting the flow of fluid from canister  46  through the gas guide  56  to an inflatable airbag (not shown) positioned adjacent to the inboard facing surface  21  of inner roof rail member  20 . Gas guide  56  is shown extending at a substantially perpendicular angle to inflator canister  46 . It is understood that other angles and orientations of gas guide  56  may be used as known by those skilled in the art. 
         [0022]    Continuing with the invention shown in  FIG. 1 , inner roof rail member  20  further includes a separate cover plate  70  which is sized and configured to substantially cover the first aperture  30  when installed. Cover plate  70  includes a first surface  71  directed toward the interior of the vehicle passenger compartment (not shown) and an opposing second surface  72  directed toward interior cavity  26  and outer roof rail member  24 . The cover plate  70  shown in  FIG. 1  includes a length  74  which, in a preferred example, is greater than the length of inflator canister  46  including any additional length as added by gas guide  56 . Cover plate  70  further includes a width  78 . As described above, length  74  and width  78  are preferably sufficient to substantially cover first aperture  30  including any material necessary to allow for fasteners to secure cover plate  70  to roof rail  14 . Cover plate  70  is preferably made from the same material as roof rail  14  as previously described but may be made from other materials suitable for the application as known by those skilled in the art. 
         [0023]    Cover plate  70  includes at least two, and preferably four, through-tabs  76  which are best seen in  FIGS. 1 and 2 . Tabs  76  are preferably stamped or punched through first surface  71  bending the still-attached tab  76  inward toward interior cavity  26  at an angle as best seen in  FIG. 2 . Tabs  76  are positioned and oriented on cover plate  70  to assist in the location and position of inflator canister  46  for secure attachment which is described below. 
         [0024]    As best seen in  FIG. 2 , in a preferred example of the invention shown in  FIGS. 1 and 2 , inflator canister  46  is securely attached to cover plate  70  prior to installation of the inflator  40  in, and cover plate  70  on, roof rail  14 . In one example of the invention, a retainer  94  is used to securely attach inflator canister  46  to cover plate  70  to form an integral inflator assembly for mounting to the roof rail  14 . In the example shown in  FIGS. 1 and 2 , retainer  94  may include a cinch-locking strap  100 . In one example, strap  100  is an elongate flexible spring steel strap that is threaded through the openings in cover plate  70  created by vertically aligned tabs  76  and positioned around inflator canister  46 . Strap  100  includes a lock  101  which is positioned near one end of the strap  100  and receives the opposing end of the strap. The loose end is threaded through the lock  101  which allows only one-way movement of the loose end of the strap through the lock preventing reverse movement back out of the lock similar to a plastic zip-strip-type fastener commonly known by those skilled in the art. The more the loose end of strap  100  is pulled through the lock, the higher the compression force is placed on canister  46  thereby securely attaching it to cover plate  70 . As shown in  FIG. 1 , one or more straps  100  may be used (two shown). It is understood that more or less straps may be used to suit the particular application. It is further understood that other fastening mechanisms such as mechanical fasteners including screws, bolts, brackets, (all not shown) may be used alone or with other fasteners as known by those skilled in the art. 
         [0025]    As shown in  FIGS. 1 and 2 , if a gas guide  56  is used, a notch or clearance hole  84  in cover plate  70  may be used to provide a pathway for gas guide  56  to pass from inflator  40  through cover plate  70 . On actuation of inflator  40 , fluid rapidly flows from inflator  40  through gas guide  56  through exit ports  64  to an airbag (not shown). 
         [0026]    On secured attachment of inflator  40  to cover plate  70 , an integrated inflator assembly is created. Integrated inflator assembly may then be attached to roof rail  14 , and preferably inner roof rail member  20 , to substantially cover first aperture  30  to completely conceal inflator canister  46  inside roof rail  14  thereby eliminating the packaging challenge existing in the art for the inflator. This is accomplished by positioning inflator  40  through first aperture  30  into interior cavity  26 . The cover plate  70  is then securely attached to inner roof rail member  20  through fasteners  80 . In a preferred example, fasteners  80  are threaded bolts used with weld nuts  82  positioned on the inner roof rail member  20  surface facing interior cavity  26  as best seen in  FIG. 2 . In a preferred example, cover plate  70  and fastener  80  substantially restore the structural integrity of roof rail  14  by substantially covering first aperture  30 . It is understood that other fastening methods other than bolts and weld nuts, for example, self-drilling or self-tapping screws, or other processes such as staking, may be used to secure cover plate  70  to roof rail  14  as known by those skilled in the art. It is further understood that other structures such as brackets and formations in the components such as darts to reinforce the areas known by those skilled in the art may be used. 
         [0027]    Referring to  FIG. 3 , an alternate example of the invention shown in  FIGS. 1 and 2  is illustrated. In this example, aperture  30  and cover plate  70  length  74  are reduced to a length smaller than the length of inflator  40  including any length added by gas guide  56 . Attachment of inflator  40  to cover plate  70  may be similar to that previously described in  FIGS. 1 and 2 . On installation of the integrated inflator assembly, including cover plate  70  and inflator  40 , inflator  40  is angled and orientated through the smaller first aperture  30  to position inflator  40  in interior cavity  26  as previously described. Cover plate  70  is then secured to inner roof rail member  20  by fasteners  80  as previously described. 
         [0028]    Referring to  FIGS. 4 and 5  and alternate example of the invention is illustrated. In the example, roof rail  14  generally includes an inner roof rail member  20  and an outer roof rail member  24  forming an interior cavity  26  as well as an inflator  40  and a gas guide  56  as previously described. In this example, a recess  90  is stamped or formed into inner roof rail member  20  deforming the substrate material inward toward interior cavity  26  and outer rail  24  forming an inner wall  92  as best seen in  FIG. 5 . 
         [0029]    Recess  90  is sized and configured to accept the full length of inflator canister  46  in a direction along longitudinal axis  54  including any additional length added by gas guide  56 . In a preferred example, recess  90  is further lengthened by 30 to 50 millimeters along the longitudinal axis  54  to provide clearance for a wire harness or electrical connector extending from inflator  40  to an inflatable restraint system controller (not shown) which initiates activation of inflator  40  to inflate the airbag on an impact event. Recess  90  is configured to extend into interior cavity  26  to accept and conceal at least a portion of a profile or diameter of canister  46  from the inboard facing surface  21  of inner roof rail  20  as best seen in  FIG. 5 . In a preferred example, at least 30% of the inflation canister  46  profile, or as shown in  FIG. 5  a diameter, is received or concealed in recess  90 . It is understood that the depth of recess  90  may vary to receive less, or as shown in  FIG. 6 , more of the inflator as more fully described below. 
         [0030]    Referring to the example shown in  FIG. 6 , one or more retainers  94  may be used to secure the inflator  40  to roof rail  14 . In one example, one or more clamps  96  are used as generally illustrated. Clamps  96  may include an enlarged flange  102  at one end that is inserted in a keyhole slot  106  or other suitable opening formed in inner roof rail member  20 . The enlarged flange  102  is inserted through slot  106  and the remainder of clamp  96  is wrapped around the outer wall  52  of canister  46  and secured at an opposite end, and on the opposing side of, recess  90  and secured to inner roof rail member  20  through fasteners  80  in a matter previously described. Clamps  96  may be made from stamped or formed, relatively rigid steel or may be made from flexible spring steel or other materials known by those skilled in the art. 
         [0031]    In an alternate example of retainer  94 ,  FIGS. 4 and 5  illustrate that clamps  96  may further include tabs  97  similar to tabs  76  in the example shown in  FIGS. 1 and 2  and include a strap  100  that wraps around canister  46  to secure inflator  40  to clamp  96  prior to installation in roof rail  14 . In the example, straps  100  are positioned through holes  98  formed by the cut-through tabs  97  and secured around inflator  40  by lock  101  as generally shown in  FIG. 2 . It is understood that other methods for attaching inflator  40  to roof rail  14  and for attaching inflator  40  to clamps  96  may be used as known by those skilled in the art. 
         [0032]    Referring again to  FIG. 6 , an alternate example of the invention shown in  FIGS. 4 and 5  is illustrated. In this example, recess  90  is formed into inner roof rail member  20  at a greater depth into interior cavity  26  as shown. With recess  90  having a greater depth, a greater portion of the profile or diameter of inflation canister  46  may be received in the recess  90  thereby extending a lesser distance from inboard facing surface of inner roof rail member  20  toward the passenger compartment. In this example, retainer  94  is shown in the form of a clamp  96  as previously described. It is understood that other methods of securing inflator  40  to roof rail  14  may be used. 
         [0033]    In a method of installing an inflatable restraint system and an airbag inflator is generally shown in  FIGS. 1-6  and as previously described. In the example shown in  FIGS. 1-3 , an inflator  40  is ultimately placed in fluid communication with an airbag (not shown). A roof rail  14  having an inner roof rail member  20  and outer roof rail member  24  is provided as previously described. The inflator is then mounted to the roof rail  14 , preferably inner roof rail member  20 . 
         [0034]    In one example of the invention shown in  FIGS. 1-3 , inner roof rail member  20  includes an inboard facing surface  21  and a first aperture  30  whereby inflator  40  is positioned through aperture  30  into interior cavity  26  and cover plate  70  is secured over aperture  30  to conceal inflator  40  within roof rail  14 . In one example of the invention, inflator  40  is attached to cover plate  70  prior to installation forming an integral inflator assembly. 
         [0035]    In another example of a method of installing an inflatable restraint system and an inflator is illustrated in  FIGS. 4-6 . In this example at least a portion of inflator  40  is received in a recess  90  formed in inner roof rail member  20  extending into cavity  26 . In one example, inflator  40  is then secured to inner roof rail member  20  by a retainer  94 , preferably clamps  96 . 
         [0036]    While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law.