Abstract:
An airbag attachment associated with a non-inflatable portion on a side curtain airbag provides loops that are sewn or otherwise attached to the non-inflatable portion of the airbag. The loops directly encircle a gas supply tube and are provided on the non-inflatable portion such that the non-inflatable portion of the airbag can be slipped over the gas supply tube and suspended similar to a shower curtain on a curtain rod. The use of mounting tabs in the region of the non-inflatable portions is eliminated. Additional attachment ties with frangible seams can be used to attach the airbag to the gas supply tube in the location of the non-inflatable portion near the loop such that the airbag can be properly folded and bundled for compact placement within the vehicle body. The loops can be passed through openings in non-inflatable portions of the airbag, each loop directly encircling the gas supply tube. The loops can be provided with an attachment hole to enable the loops to be fastened to the vehicle body similar to a mounting tab. Upon deployment the side curtain airbag will remain suspended from the loops.

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates generally to a side curtain airbag assembly for motor vehicles. More specifically the invention relates to an anti-wrap feature for a side curtain airbag. 
     Side curtain airbags provide cushioning between vehicle occupants and the doors and windows of a vehicle during a lateral impact. Side curtain airbags can extend from a front pillar all the way to the rear of a vehicle and in large mini vans or sport utility vehicles the airbags can cover not only the front and second row seats, but even further back to the additional rear seats in such vehicles. The airbags can extend between any designated set of pillars of the vehicle from the front A pillar, B pillar, C pillar to even the D rear pillar of a vehicle. 
     Due to the large volume of inflation gas needed to deploy such airbags they are commonly provided with flat or uninflated sections in areas of the airbag where a vehicle occupant will not likely strike his or her head against the side portions of the vehicle during a collision. Such areas are commonly located in the front portion of the vehicle near the A pillar and extend back a distance sufficient that this space does not need to have a gas filled cushion. Similarly in locations between certain seat locations it is not likely that an inflatable section of the airbag is needed. What is needed in these areas instead of a 3-dimensional inflatable region filled with gas is simply one or more layers of material forming the airbag that is not inflated. It is a two-plane configuration that simply unfolds with the rest of the airbag during inflation. The non-inflated portion of the airbag in front of or rearward of the inflatable portions of the airbag is commonly called a sail portion. The sail portion is an efficient way of limiting the amount of gas required to deploy side curtain airbags. To deploy a side curtain airbag an inflator is commonly used at one end or the opposite end of the airbag depending on the size of the vehicle. Alternatively, the inflator can be placed in the middle of a side curtain airbag on a larger vehicle like a minivan such that the inflation gas is sent to a T section and then to gas supply tubes extending in opposing directions such that forward and rearward cushions can be inflated relatively simultaneously. Smaller vehicles commonly have the inflator at the A pillar and the gasses flow from the A pillar location through the fill tube to inflate the side curtain airbags which are configured to provide protection for the vehicle occupants in the front or both front and rear seats. 
     Typically the gas supply tubes extend inwardly of the airbag and communicate the gas through exhaust ports or holes that can be strategically placed to fill the separate inflatable compartments or the end of the gas supply tube can simply be an outlet port located at a strategic location of the cushion depending on the simplicity or the complexity of the design. These airbags are typically pre-assembled and have attachment tabs with anchoring features such that they can be physically fastened or screwed into the vehicle body in the region of the pillars. The assemblies preferably have the airbag folded such that upon activation certain tear seams are ripped apart. Typically the airbag in the area to be inflated has the gas supply tube inserted through an elongated channel portion of the airbag and upon actuation the gasses inflate and deploy the airbag in a quick manner such that the side curtain can deploy rapidly. A common problem in such airbags is that they must be properly positioned and located so the deployment is uniform and the entire side curtain airbag moves downward towards the area to be protected in a uniform and rapid manner. 
     For airbags having sails or flat portions, with mounting tabs located near the sail portion the deployment of the airbag can be impaired by a mounting tab. 
     It is a feature of the present invention to provide a side curtain airbag with said portions that eliminate or greatly reduce the possibility of the side curtain being constricted. It is a further feature that a means is provided to ensure that the airbag always deploys properly and that there are no areas in which the airbag can twist or be prevented from proper deployment. 
     SUMMARY OF THE INVENTION 
     The present invention as described provides an airbag means for attachment in the region of a sail portion on a side curtain airbag that provides loops sewn or otherwise attached to the sail portion of the airbag. The loops are designed to encircle a gas supply tube and are provided at the ends of the sail portion such that the sail portion of the airbag can be slipped over the gas supply tube and is suspended in a sliding manner similar to a shower curtain on a curtain rod. The use of mounting tabs in the region of the sail portions is eliminated. In the preferred embodiment additional attachment ties with frangible seams can be used to attach the airbag to the fill tube in the location of the sail portion adjacent the loop such that the airbag can be properly folded and bundled for compact placement within the vehicle body. In another embodiment the loops are passed through openings or slots, flat, uninflated portions in the airbag and also encircle the gas supply tube. The loops can be provided with an attachment hole to enable the loop to be fastened to the vehicle body similar to a mounting tab. Upon deployment the airbag can be suspended from the loops. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a side curtain airbag in a deployed condition showing the sail portion in an A pillar position. 
         FIG. 2  shows an alternative embodiment of the side curtain airbag. 
         FIG. 3  shows a folded airbag employing loops according to the present invention. 
         FIG. 4  is an enlarged view of a pair of loops sewn to the airbag. 
         FIG. 5A  shows a side curtain airbag suspended between the C and D pillars. 
         FIG. 5B  shows the side curtain airbag of  FIG. 5A  shown in a folded condition with a frangible sleeve encircling the assembly. 
         FIG. 6A  shows another embodiment side curtain airbag having a short mounting rod affixed to the airbag from which a sail portion can be attached according to the present invention. 
         FIG. 6B  shows the embodiment of  FIG. 6A  shown in a folded condition. 
         FIG. 7  is a plan view of a second alternative embodiment according to the present invention. 
         FIG. 8  is a plan view of a third alternative embodiment of the present invention similar to that of  FIG. 7  but with an end mounted inflator. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a side curtain airbag assembly  100  in a deployed condition for a typical passenger vehicle wherein the side curtain airbag  20  has an inflatable cushion portion  22  covering the front side window and extending towards a sail portion  24  near the A pillar of the vehicle. The side curtain airbag assembly  100  is fastened to the vehicle structure by one or more means for attachment including mounting tabs  30  that extend from the top of the side curtain airbag  20 . The mounting tabs  30  are typically provided in two or more locations that are bolted or otherwise fastened to the vehicle structure using fasteners inserted through holes  32  in the mounting tabs. The side curtain airbag assembly  100  extends as shown toward the rear portion of the vehicle and has a plurality of inflatable cushion portions  22  that cover the window portions and certain pillars as shown. Each of the cushion portions  22  is filled with inflation gas that exits from the gas supply tube  4  as illustrated. The sail portion  24  as shown has attachment loops  10  sewn or otherwise attached to the sail portion  24  wherein the loops  10  directly encircle the gas supply tube  4  and is suspended therefrom as shown. 
       FIG. 2  shows an alternative embodiment of the side curtain airbag  200  for a larger sized vehicle, either a minivan or a sport utility extending from the A to D pillar position wherein a sail portion is provided in both a front and rear portion of an airbag upon deployment. In such a vehicle the side curtain airbag assembly  200  as shown deployed has the airbag inflator  2  positioned intermediate between the front and rear seat preferably along the B pillar or C pillar. The inflator  2  is connected to a T section  3  that extends to gas supply tubes  4  in both forward and rearward directions. The sail portion  24  near the D pillar may further include additional sail portions  24  in areas not needing inflation or cushioning to protect a vehicle occupant. As shown, one or more means for attachment  30  for connecting the assembly to a vehicle are used to attach the airbag assembly. The means for attachment or tabs  30  are generally referred to as mounting tabs, which are integral or attached to the airbag  200  along an attachment end and can include a fastener inserted through a hole  32  that can be attached or fastened directly to the vehicle body. 
       FIG. 3  shows a folded side curtain airbag employing attachment loops according to the present invention. The present invention provides one or more attachment loops  10  attached to the side curtain airbag  20  directly encircling the gas supply tube  4  from which the side curtain airbag  20  is suspended. The attachment loops  10  preferably are attached to the side curtain airbag  20  in an area where the non-inflatable sail portion  24  is located.  FIG. 4  is an enlarged view of a pair of loops  10  sewn to the side curtain airbag in the sail portion location. The loops  10  as shown are preferably made of a strong nylon webbing material that can be sewn or stitched with threads  9  directly to an end of the side curtain airbag  20  such that the side curtain airbag  20  can be suspended from the loop  10  directly encircling the gas supply tube  4  and physically restrained simply by means of the combination of the gas supply tube  4  and the attachment loops  10  in that location. The side curtain airbag assembly  20  at the front A pillar can optionally be anchored to the vehicle body by a tether  21  as shown in  FIG. 3 , which is physically attached to a sail portion  24  of the side curtain airbag  20  which extends towards an inflator  2  that provides inflation gas for deployment. 
     With reference to  FIG. 3 , the attachment loop  10  is shown wherein it directly encircles a gas supply tube  4  such that upon assembly the gas supply tube  4  can simply be slipped through the opening in the loop  10  and the sail portion can be suspended therefrom. The gas supply tube  4  will then extend inward into a channel in the neck of the side curtain airbag  20  and communicates or is open to the cushion portions  22  of the side curtain airbag  20  that are intended to be inflated during deployment. Thereafter the side curtain airbag  20  can be folded and attached to the airbag inflator  2  if not already so attached to the gas supply tube  4  by conventional means. The folded side curtain airbag  20  can be maintained in this folded condition by covering the folded side curtain airbag  20  excluding the sail portion  24  with a breakable cylindrically shaped cover or sleeve  25 . Further, a plurality of attachment straps with breakaway means such as separate frangible ties or tape  40  are wrapped and tied or taped about the folded sail portion  24  and folded inflatable cushion portions  22  suspended on the gas supply tube  4 . The frangible ties or tape  40  as well as the cover  25  will break upon activation of the side curtain airbag  20  and allow the side curtain airbag  20  to drop and fill in a normal fashion. However, it is important that the attachment loops  10  be employed in order to keep the rather thin sail portion  24  from wrapping, being wrapped or getting twisted about the gas supply tube  4 . This is a problem in that the side curtain airbag  20  in the locations of the sail portion  24  can become constricted about the gas supply tube  4  preventing proper deployment of the side curtain airbag  20 . The locations of sail portion  24  can either be at the A pillar location or could be intermediate thereof in any position along the side curtain airbag  20 . As shown, one or more of the attachment loops  10  will be used to suspend the side curtain airbag  20  in a fashion similar to a shower curtain on a rod wherein the side curtain airbag  20  can actually physically slip along the gas supply tube  4  if so desired. The ties or tape  40  are designed to break with minimal resistance upon activation of the side curtain airbag  20 . In one embodiment the frangible ties or tape  40  are made of a lightweight adhesive backed plastic tape. 
     With reference to  FIGS. 5A and 5B , another embodiment of the present invention is shown.  FIG. 5A  shows a side curtain airbag  20  suspended between the C and D pillars having a sail portion  24  attached to a gas supply tube according to the present invention.  FIG. 5B  shows the side curtain airbag of  FIG. 5A  in a folded condition with a frangible sleeve encircling the assembly. The side curtain airbag  20  extends between the C and D pillars having the inflatable cushion portions  22  covering the rear side windows and the sail portion  24  being near the D pillar. As shown the inflator is located in the C pillar area and is connected to the gas supply tube  4 , which extends through a channel in the side curtain airbag  20  to an end wherein the sail portion  24  is suspended by attachment loops  10  according to the present invention. As shown the side curtain airbag is clamped about the gas supply tube  4  by clamp  27  to seal the side curtain airbag  20  against the gas supply tube  4 . The exposed end of the gas supply tube  4  has no passages for the inflation gas to escape.  FIG. 5B  shows the side curtain airbag  20  folded with mounting tabs  30  extending through slots  26  in the sleeve cover  25 . 
       FIG. 6A  shows another embodiment of a side curtain airbag having a short mounting rod affixed to the side curtain airbag from which a sail portion can be attached according to the present invention.  FIG. 6B  shows the embodiment of  FIG. 6A  in a folded condition. The second alternative embodiment side curtain airbag assembly is shown wherein the side curtain airbag  220  has an internal channel into which inflation gasses pass directly from the inflator  2  to connector  3 . The channel  28  is formed from the fabric of the side curtain airbag  220 . At the end of the channel  28  a tube or rod  4 A is inserted in the opening and held by a clamp  27 . The sail portion  24  is then looped over the short tube or rod with the attachment loops  10  of the present invention.  FIG. 6B  shows this assembly in the folded condition with the mounting tabs  30  extending through slots  26  in the sleeve  25 . The rod  4 A can be a plastic molded component attached to the side curtain airbag  220 . 
     While the attachment loops  10  are shown in the locations of the non-inflatable sail portion  24  it is possible that such loops  10  could be used in other areas of the side curtain airbag  20  such that the entire side curtain airbag  20  could be alternatively suspended upon the gas supply tube  4  if so desired, however, as is commonly recognized a portion of the gas supply tube  4  will extend inward a sleeve or pocket or internal conduit portion of the side curtain airbag  20  so that the gas can be passed from the gas supply tube  4  into the cushion  22  to provide filling of the side curtain airbag  20 . In such a case the attachment loops  10  would be required in the regions wherein the fill tube  4  is internally placed in a sleeve  25  or internal conduit or channel portion  28 . 
       FIG. 7  is a plan view of a second alternative embodiment showing a suspended side curtain airbag  240  attached by attachment loops passing through the side curtain airbag and further having an inflator mid mounted and directly encircled by an attachment loop according to the present invention. In this embodiment a side curtain airbag  240  is illustrated suspended from a gas supply tube  4 , which extends across most of the side curtain airbag. The suspended side curtain airbag  240  has a plurality of holes  31  in locations  33  where the side curtain airbag does not normally inflate. The holes provide access slots  31  through which a modified attachment loop  10 A can be inserted. The loop  10 A can pass through the holes encircling both a portion of the side curtain airbag nearest the fill tube and the fill tube  4  as shown. The attachment loops  10 A are distinguished from the attachment loops  10  previously discussed in that the free ends of the loops  10 A can be overlaid and a hole  11  formed therethrough wherein a fastener such as a shoulder bolt can be passed through each hole  11  through that location and attached directly to the vehicle converting the attachment loops  10  to attachment loop tabs  10 A. The attachment loop tabs  10 A provide not only a means of suspending a side curtain airbag similar to a shower curtain, but also provide a means for affixing the side curtain airbag  240  to the vehicle structure. As shown the side curtain airbag  240  has a mid mounted inflator  2  that is connected to the gas supply tube  4  at an L location  1  as shown. The gas filled inflator  2  is attached to the side curtain airbag  240  using an attachment loop  10 B. The attachment loop  10 B directly encircles the airbag inflator  2  in such fashion that the inflator  2  can suspend the side curtain airbag  240  similar to that of the attachment loop  10  used around the end of a gas supply tube  4 . As shown at the end location near the inflator  2  are two more conventional mounting tabs  30  with access holes  32  through which fasteners can be inserted. This embodiment enables the entire side curtain airbag  240  to be suspended by the loops  10 A,  10 B and conventional mounting tabs  30 . The loops  10 A provide not only a suspension of the side curtain airbag  240  but also a means for attachment to the vehicle. 
       FIG. 8  is a plan view of a third alternative embodiment of the present invention similar to that of  FIG. 7  but with an end mounted inflator. The side curtain airbag  260  has similar holes  31  in areas or locations  33  of the side curtain airbag  240  that are not normally inflated. The holes or slots  31  provide access such that an attachment loop  10 A can be inserted therethrough directly encircling the gas supply tube  4  as previously discussed and then a hole  11  provided therethrough for mounting to the vehicle. As shown the inflator  2  is located in an end of the side curtain airbag and on that side of the side curtain airbag is an attachment loop  10 B as previously discussed directly encircling the inflator  2 . Each of the embodiments illustrated in  FIGS. 7 and 8  can then be foled and then taped as previously discussed using the ties or tape  40  as previously shown in the other embodiments. As shown each of these embodiments provides a unique way of suspending a side curtain airbag similar to a shower curtain such that the side curtain airbag is capable of sliding along the gas supply tube and being suspended therefrom. 
     The combination of loops  10  for directly encircling a gas supply tube along a sail portion of a side curtain airbag can be used in combination with the other attachment loops  10 A,  10 B in such a fashion that the entire side curtain airbag can be suspended using such loops in any combination thereof. 
     The present invention provides for the installation in a vehicle of a side curtain airbag assembly by using conventional mounting tabs that can be fashioned to at least one or both ends of the side curtain airbag assembly to provide a secure attachment to the vehicle frame which can be complemented by the loops  10 ,  10 A or  10 B which can be provided in between these attachment locations to ensure that the side curtain airbag does not get wrapped or twisted about the gas supply tube  4 . The loops  10  preferably are positioned in locations where the side curtain airbag is actually external of the gas supply tube  4  or loops  10 B around an externally positioned inflator. In either case the addition of these loops provides a beneficial anti-wrap feature that prevents the side curtain airbag from being inadvertently twisted about the gas supply tube  4  upon assembly to the vehicle. As used herein anti-wrap means avoiding any portion of the side curtain airbag becoming twisted around a fill tube upon assembly so as to constrict proper depolymer. This greatly benefits and simplifies the assembly operation when the side curtain airbags are physically attached to the vehicle and prevents unwanted constrictions to occur to impede a proper side curtain airbag deployment. 
     The invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes can be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings are accordingly, to be regarded in an illustrative rather than restrictive sense.