Abstract:
A side impact or rollover protection restraint system ( 20 ) is presented having an air bag ( 22 ) which upon inflation is of sufficient height to extend from proximate a seat ( 25 ) of a vehicle to a location generally adjacent the shoulder of a 50th percentile sized seated occupant such that the inflated air bag will lie between the occupant and a side portion of the vehicle. The air bag including a first and a second panel ( 24   a   ,24   b ) of material that are joined together to create a pair of inflatable volumes ( 36,38 ) and an internal tether ( 30 ) for forming a corresponding bridge between predetermined regions of each of the first and second panel ( 24   a   , 24   b ) such that upon inflation of the air bag these regions are spaced from one another by at least one internal tether, wherein the air bag includes more than one inflatable volume, wherein each volume includes corresponding internal tethers or separator means.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit of U.S. Provisional Application No. 60/558,297, filed on Mar. 31, 2004 and U.S. Provisional Application No. 60/557,719, filed on Mar. 30, 2004. The disclosures of the above applications are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates to an inflatable side air bag module assembly designed to provide occupant protection to vehicle passengers during a side impact event. More particularly, the module is mounted proximate the vehicle door and concealed by the vehicle seat.  
       BACKGROUND AND SUMMARY OF THE INVENTION  
       [0003]     Upon lateral impact, an air bag deploys between the occupant and intruding object to protect the outboard front and rear occupants. The present invention defines an air bag having multiple inflatable chambers within the air bag that insures the front and the rear panels of the air bag remain spaced apart to provide added protection for the occupant while keeping the chamber volume at an acceptable level.  
         [0004]     In order to control the inflated shape and volume of an air bag it has been proposed to directly sew the front and rear panels of the cushion together. This type of construction defines various chambers in the air bag (in which certain portions of the front and rear panels are spaced apart) but this construction also places other portions of the panels in direct contact, particularly at the separator sew lines, thus reducing spacing which reduces the “cushioned depth” between the occupant and a side of the vehicle. Additionally, inflation gasses often impinge on critical cushion components. This is not the case with the present invention.  
         [0005]     Accordingly the invention discloses a side impact protection restraint system having an air bag of sufficient length to extend from a vehicle seat to an occupant&#39;s chest. The air bag, upon inflation, is of sufficient height to extend from proximate the seat of the vehicle to a location generally adjacent the shoulder of a 95 th  percentile sized seated occupant such that the inflated air bag will lie between the occupant and a side portion of the vehicle. The air bag includes a first and a second panel of material joined together to create a pair of inflatable volumes and a single internal tether or separator for forming corresponding bridges between predetermined regions of the first and second panels. The internal tether is positioned at an acute angle between 45 and 65 degrees with respect to the seat back angle, so as to position the lower chamber below the occupant&#39;s ribs. Upon inflation of the air bag, the internal tether functions to regulate flow of the deployment gasses.  
         [0006]     It is an object of the present invention to provide an air bag to protect one or more vehicle occupants in a side impact crash event. The features, functions, and advantages can be achieved independently in various embodiments of the present invention or may be combined in yet other embodiments. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:  
         [0008]      FIG. 1  illustrates a side plan view of an inflated air bag with angled chamber separator;  
         [0009]      FIG. 2  is a plan view of the exterior of a cushion subassembly of the cushion shown in  FIG. 1 ;  
         [0010]      FIG. 3  is a perspective view of the cushion of  FIG. 1  shown in vehicle position;  
         [0011]      FIG. 4  is rear view of the inflator insertion portion of the cushion shown in  FIG. 1 ;  
         [0012]      FIG. 5  illustrates a sectional view of the cushion shown in  FIG. 1 ;  
         [0013]      FIGS. 6   a  and  6   b  illustrate a cross-sectional view and plan view of the internal tether shown in  FIG. 5 ;  
         [0014]      FIG. 7  illustrates the cushion shown in  FIG. 4  with an inflator inserted; and  
         [0015]      FIGS. 8   a  and  8   b  represent the cushion shown in  FIG. 6  with an inserted inflator. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0016]     The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.  
         [0017]      FIGS. 1 and 3  illustrate plan views of an inflated air bag with angled interior tether used in a side impact module generally shown as  20 . The module  20  comprises an air bag  22  of sufficient length to extend generally the length of a seated occupant&#39;s torso seated in a vehicle. As illustrated, air bag  22  extends from the vehicle&#39;s seat  25  to the shoulder of the occupant  31 . In other applications, the air bag  22  may extend above the shoulder so as to protect the occupant&#39;s head, for example. The air bag  22  is of sufficient height such that when deployed the air bag  22  will lie between the seat of the vehicle and the upper torso and/or shoulder of the outboard seated occupant (95th percentile male). When inflated, the air bag  22  will also lie against the vehicle&#39;s internal side.  
         [0018]     As seen in  FIG. 2 , the air bag  22  comprises a single main panel  21  that is folded about its centerline  23 ; the folded-over portions of the main panel  21  are referred to as a first or front  24   a  and a second or rear panel  24   b . While for strength reasons it is preferred the main panel  21  be formed of a single piece of fabric, as can be appreciated, the air bag can be made of a plurality of separate panels of material joined together (along a centerline  23  or otherwise) as opposed to using a folded-over main panel  21 . In the illustrated embodiment of the invention, the main panel  21  is a woven material such as nylon that is uncoated in a known manner to control air permeability. A low permeability, coated fabric may also be used.  
         [0019]     With regard to the fabric, air bag material permeability and/or its coating are chosen to match the required time the air bag should be inflated. As will be seen from the discussion below, the air bag  22  is formed by sewing the remaining three sides or periphery (after it is folded over centerline  23 ) and interior panel of the air bag together to form an inflatable cushion  22  having multiple chambers. The side  26  of the air bag  22 , as shown in  FIG. 1 , is formed using a seam  28 , which joins panels  24   a  and  b  together. The sides of the panels are joined by one or more chain seams  28   a  and  28 . Optionally, reinforcement stitching can be added at an area adjacent to the tether  30 . Located on either side of the centerline  23  is a plurality of mounting features such as tabs  39 , each tab  39  is coupled to a respective panel  24   a  and  24   b  shown in  FIGS. 3 and 4 .  
         [0020]     The tabs  39  are used to reinforce the cushion and seal the insertion aperture  44 . A plurality of fasteners from the inflator mount, not shown, are used to secure the air bag  22  at the centerline  23  to the seat The air bag includes an inlet in the form of an aperture  44  integrally formed between the panels  24   a  and  24   b . In  FIG. 1 , the aperture  44  is located toward the bottom  42   a  of air bag  22  at the centerline  23 , preferably adjacent to the internal tether  30 . The internal tether  30  is positioned and angled to form an initial inflation lower chamber  36 , which is preferably positioned below the abdomen of a 5 th  percentile, seated, female occupant. The tether  30  also divides the air bag  22  into an upper chamber  38  (see  FIG. 6B ).  
         [0021]     An air bag inflator  60  is inserted in opening  44 . The inflator  60  includes a mounting bracket  62  to permit the inflator  60  to be mounted to an adjacent structural component such as the seat frame or at a designated location along a seat back frame. The inflator  60  may be a solid propellant, hybrid, augmented or liquid inflator of known variety, which upon activation produces or supplies pressurized inflation gas to the air bag  22 . The inflator  60  includes a plurality of radially oriented output ports  64  or a gas diverter housing (not shown) to direct the inflation gas into the air bag.  
         [0022]     Reference is made to  FIGS. 1 and 3 . Shown is an internal tether  30 , which is arranged relatively acute with respect to the vehicle seat cushion  25  or seat back angle. The internal tether  30  is coupled to panels  24   a ,  24   b  and about the centerline  23  at a generally acute angle A between 45 and 65 degrees, relative to the fold line of the cushion, which is directed downward toward the vehicle&#39;s floor. Upon initiation of the inflator  60 , gasses flow, see arrow B, from the inflator&#39;s exit port(s)  64  along the length of the internal tether  30 . Along the seam, at the far end of the tether, is an optional row of reinforcement stitches  28   b.    
         [0023]      FIG. 2  shows a subassembly which includes the main panel  21  of the air bag of  FIG. 1 , laid flat upon a work surface. The centerline  23  is also visible. The two sets of tabs  39  for each of the cushion portions are located adjacent the opening  44 . As can be appreciated, one of benefits of using a relatively small insertion opening  44  is the ease of construction and ability to restrict gas leakage. Each tab  39  is laid on one of the air bag panels, such as  24   a , and placed in the desired location, which is identified by pre-printed markers or lines. Each tab  39 , at seam  37 , is sewn along its side to the air bag panels  24   a  and  24   b.    
         [0024]     As can be seen in  FIG. 4 , the tabs  39  are configured to be wrapped around and secured about the inflator  60  by bracket or clamp  62   b  to permit the inflation gasses to flow directly therein. A hole  66  (see  FIG. 2 ) is formed along the centerline  23  to accommodate lead wires to the squib or the electrical connection end of the inflator.  
         [0025]     As shown in  FIGS. 5 and 6   a , disposed adjacent to the internal tether  30  is a pair of heat shields  32  and  34  that extend from separator  30  to at least a portion of the sides of the lower chamber  36 . The heat shields  32  and  34  preferably are formed of a single-sided silicon-coated material of a single panel sharing the fold line  23  of the main panel  24 . The heat shields  32  and  34  extend along the sides of the cushion from the stitching  68   a,b  at the separator  30  to a lower set of stitching  65 . Additionally, the heat shields  32  and  34  are coupled to each other at the seam of the lower chamber  36 . The coupling of the two heat shield panels forms a pocket, which protects the obverse side  47  of the cushion from the discharging gasses.  
         [0026]     The internal tether  30  can be of varying predetermined lengths depending upon the chosen angle A. Additionally, the cushion&#39;s width can be regulated by varying the width of the internal tether  30 . The internal tether  30  has a pair of vents  46  and  48 , which fluidly couple the first chamber  36  to the second chamber  38 . The first vent  46  is formed by a semicircular cutout at a first end of the located internal tether  30 . The semicircular cutout is located adjacent the centerline  32  of the air bag. The second vent  48  is a 1-inch diameter hole disposed generally centrally within the internal tether  30 . At least a portion of the inflator  60  is disposed through the first vent  46  to at least partially restrict the flow of deployment gasses into the second chamber  38 . Specifically, the inflator  60  reduces the available size of the passage formed by the first vent and the inflator body and obstructs the flow and therefore restricts the flow of gasses through the first vent  46  during the initial inflation of the cushion  22  while allowing an increased flow of gasses through the second vent  48  later in the deployment event. The internal tether  30  functions to regulate the width of the cushion  22  upon inflation while regulating the flow of compressed gasses from the lower (first)  36  to the upper (second) chamber  38 .  
         [0027]     The first chamber  36  of the air bag  22  is filled first with the inflation gas. Subsequently, chamber  38  fills to protect the upper torso. The size and placement of chambers  36  and  38  will vary with the particular vehicle and seating arrangement. By reducing the inflated volume of the first chamber  36 , it is possible to use a smaller capacity inflator as less inflation gas is needed to inflate the air bag.  
         [0028]     Disposed between these cushions is the internal tether  30  that joins together generally opposing regions of the front panel  24   a  and the rear panel  24   b . Numeral  62  identifies the seams joining the internal tether to panel  24   a , while numeral  64  identifies the sewn seams joining the heat shields to the side panels  24   a  and  24   b.    
         [0029]      FIG. 6   a  is a cross-sectional view of the cushion  22  having an internal tether  30 . As can be seen, this internal tether  30  includes the sides  68   b  and  68   a , which are sewn to a corresponding air bag panel  24   a  or  24   b . The internal tether  30  includes previously mentioned vents. As can be appreciated, when the air bag  22  is inflated, the various panels  24   a  and  24   b  will tend to be forcefully pulled apart and resist further inflation of the cushions. The interior tether  30  and the main panel are made of woven material arranged at a bias (45°±5°) to the air bag panels  24   a,b . The opening  44  is preferably round in shape. The sew line coupling one side of the internal tether to one side panel is generally in alignment with the sew line of the other side of the internal tether in the second panel.  FIG. 6   b  is a plan view of the internal tether  30  shown in  FIG. 6   a.    
         [0030]     Reference is again made to  FIG. 7 . As can be seen, the tabs  39  are wrapped about mounting bracket  62  of the inflator  60 . The inflator  60  is shown partially disposed within both the first and second chambers. In this regard, the inflator  60  is disposed through the first vent  46 . Although wires are shown disposed through the aperture  66  formed along the centerline, it is envisioned that a portion of the inflator  60  can be positioned through the aperture to allow for easy electrical connection with the inflator.  
         [0031]      FIG. 8   a  is a cross-sectional view of the cushion  22  having an exemplary internal tether  30 . As can be seen, this internal tether  30  includes the first vent  46  with the inflator disposed therethrough. As can be appreciated, when the air bag  22  is inflated, the various panels  24   a  and  24   b  will tend to be forcefully pulled apart and resist further inflation of the cushions. The output ports  64  of the inflator  60  are positioned so that the inflation gasses impinge on the heat shields as the cushion is filled.  FIG. 8   b  shows a side cross-sectional view of the cushion with inserted inflator  60 . The inflator  60  is partially positioned through the hole  66  formed along the centerline  23  of the main panel  21 . As shown, the inflator  60  is coupled to the cushion using a snap ring  69 .  
         [0032]     The cushion is formed by sewing the internal tether and one heat shield to the cushion main panel. Upon sewing the internal tether to panel  24   b  of air bag  22 , panel  24   a  is positioned on top of panel  24   b  and the internal tether  30  and second heat shield  34  are then joined to panel  24   b . With the panels  24   a  and  24   b  in this orientation, the top and sides of the air bag are secured together along peripheral seams  28   c ,  28   a  and  28   b.    
         [0033]     Subsequently, the air bag is folded into a long, compact, cylindrical configuration. An additional benefit of the internal tether  30  is that the various folds in the air bag  22  can be arranged such that the various seams of each internal tether  30  do not lie on top of each other, thereby permitting the air bag  22  to be folded in a compact configuration. To keep the air bag  22  in this rolled configuration, the air bag  22  is enveloped in a tearable cover such as sewn fabric, polyurethane with tear seam or snap-together (and openable) semi-hard plastic cover. The folded, enveloped air bag is then secured to the vehicle seat using a plurality of fasteners.  
         [0034]     Many changes and modifications in the above-described embodiment of the invention can, of course, be carried out without departing from the scope thereof. Accordingly, that scope is intended to be limited only by the scope of the appended claims. While various preferred embodiments have been described, those skilled in the art will recognize modifications or variations which might be made without departing from the inventive concept. The examples illustrate the invention and are not intended to limit it. Therefore, the description and claims should be interpreted liberally with only such limitation as is necessary in view of the pertinent prior art.