Abstract:
Systems and methods for folding airbags are disclosed. An airbag folding body includes a cavity having a rear wall and a top wall, the rear wall being opposite an entrance of an airbag cushion. The airbag folding body also includes a notch formed at an intersection of the top wall and the rear wall, the notch being adapted to capture, engage or secure a leading edge of the airbag cushion. The rear wall is adapted to direct the leading edge of the airbag toward the notch.

Description:
CROSS-REFERENCE  
       [0001]     This application claims the benefit under 35 U.S.C. 119(e) of U.S. Patent Application No. 60/639,325, filed Dec. 28, 2004, which is incorporated herein by reference in its entirety. 
     
    
     BACKGROUND  
       [0002]     The present invention relates generally to the field of safety restraint systems. In particular, the invention relates to methods and systems for folding airbags for use as, for example, side air-bag curtains.  
       SUMMARY  
       [0003]     According to an embodiment of the present invention, an airbag folding body includes a cavity having a rear wall and a top wall, the rear wall being opposite an entrance of an airbag cushion. The airbag folding body also includes a notch formed at an intersection of the top wall and the rear wall, the notch being adapted to capture, engage or secure a leading edge of the airbag cushion. The rear wall is adapted to direct the leading edge of the airbag cushion toward the notch.  
         [0004]     In another embodiment of the invention, a method of folding an airbag includes causing relative movement of an airbag cushion toward a folding body, the folding body having a cavity with a rear wall and a top wall, and directing a leading edge of the airbag cushion toward a notch formed at an intersection of the top wall and the rear wall of the folding body, the notch being adapted to capture, engage or secure the leading edge.  
         [0005]     According to another embodiment of the invention, an airbag folding arrangement includes a first comb portion having two or more folding regions, the folding regions being separated by stationary blades, and a fastener for securing an end of an airbag cushion. The arrangement also includes a second comb portion having one or more movable blades adapted to translate at least partially into the folding regions, thereby forming a fold of an airbag cushion positioned between the first comb portion and the second comb portion.  
         [0006]     In another embodiment, an airbag folding method includes positioning an airbag cushion between a first comb portion and a second comb portion, the first comb portion having two or more folding regions, the folding regions being separated by stationary blades, the second comb portion having one or more movable blades positioned above corresponding folding regions and being adapted to translate at least partially into the folding regions; securing one end of the airbag cushion on one side of the folding regions; and translating the movable blades sequentially into the folding regions proceeding from a folding region closest to the secured end of the airbag cushion to a folding region further from the secured end of the airbag cushion.  
         [0007]     It is to be understood that both the foregoing general description and the following detailed description are exemplary and exemplary only, and are not restrictive of the invention as claimed. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     These and other features, aspects, and advantages of the present invention will become apparent from the following description, appended claims, and the accompanying exemplary embodiments shown in the drawings, which are briefly described below.  
         [0009]      FIG. 1  is a perspective illustration of an airbag folding arrangement according to an embodiment of the invention;  
         [0010]      FIGS. 2A and 2B  are cross-sectional views taken along II-II of embodiments of the airbag folding arrangement of  FIG. 1  illustrating a folding process;  
         [0011]      FIG. 3  is a cross-sectional illustration of an airbag folding arrangement according to another embodiment of the invention; and  
         [0012]      FIG. 4  illustrates an airbag folding process using the airbag folding arrangement of  FIG. 3 . 
     
    
     DETAILED DESCRIPTION  
       [0013]     Referring to  FIG. 1 , an embodiment of an airbag folding arrangement is illustrated. The airbag folding arrangement  100  is adapted to fold an airbag  110  into a folded configuration for stowing of the un-inflated airbag. Such folding arrangements may be useful for airbags used for airbag curtains for side-impact protection, for example. The dimensions of the cushion  110  may be selected according to the desired use.  
         [0014]     As shown in  FIG. 1 , the airbag folding arrangement  100  includes a folding body or push-in scoop  200 . As indicated by the arrow, the folding body  200  is adapted to be moved toward the airbag  110 . The movement of the folding body  200  may be achieved by a mechanism (not shown) for pushing the entire body toward the airbag  110 . In other embodiments, the folding body  200  may be stationary, while a conveyor (or other moving mechanism) may be provided to move the airbag  110 . The speed of the movement of the airbag  110  and the folding body relative to each other may be determined according to certain factors such as, for example, the dimension and material of the airbag  110 .  
         [0015]      FIGS. 2A and 2B  illustrate the folding body  200  and the use of the folding arrangement  100  of  FIG. 1  in greater detail. The folding body  200  includes a bottom wall  210 , a rear wall  220  and a top wall  230  forming a cavity  250 . The dimensions of the cavity  250  and the surrounding walls  210 ,  220 ,  230  may be selected to produce the desired dimensions of the folded airbag. The bottom wall  210  may include a ramp  212  formed at the leading edge to facilitate the direction of the airbag  110  into the cavity  250  as the airbag  110  and the folding body  200  are moved relative to each other. The ramp  212  allows the airbag  110  to be essentially scooped into the cavity  250 . The lower end of the rear wall  220  is provided with a rounded transition to the bottom wall  210  to facilitate routing of the airbag fabric. As the airbag  110  and the folding body  200  are moved relative to each other, the leading edge  112  of the airbag  110  is directed upward and into the cavity  250 .  
         [0016]     As shown in  FIGS. 1, 2A  and  2 B, the rear wall  220  is substantially perpendicular to the bottom wall  210 . In certain embodiments, the rear wall may be slightly tilted so that the angle between the bottom wall  210  and the rear wall  220  is slightly greater than 90 degrees. For example, the angle between the bottom wall  210  and the rear wall  220  may be between 90 and 100 degrees. The angle may also be greater than 100 degrees up to 120 degrees. The rear wall  220  causes the leading edge  112  of the airbag  110  to turn upward as the airbag  110  and the folding body  200  are moved relative to each other.  
         [0017]     The top wall  230  is substantially parallel to the bottom wall  210  and forms an upper barrier for the folded airbag. Thus, the distance between the bottom wall  210  and the top wall  230  determines the maximum length of each fold of the folded airbag.  
         [0018]     A notch  252  is formed in the cavity at the corner of the rear wall  220  and the top wall  230 . The notch  252  is formed to capture, engage or secure the leading edge  112  of the airbag  110 , as illustrated in  FIG. 2A , as the leading edge  112  travels along the rear wall  220 . As shown in  FIG. 2A , notch  252  is formed so as to prevent the movement of the leading edge  112  of the airbag cushion beyond the corner of the rear wall  220  and the top wall  230 . The scope of the present invention includes other alternative features that may be provided within the cavity to capture, engage or secure the leading edge  112  of the airbag cushion, and is not limited to the notch  252 .  
         [0019]     With the leading edge  112  of the airbag  110  secured in the notch  252 , the airbag  110  begins folding with continued relative movement between the airbag  110  and the folding body  200 , as shown in  FIG. 2B . The continued relative movement between the airbag  110  and the folding body  200  causes the airbag  110  to continue entry into the cavity  250  via the ramp  212 . The airbag  110  is forced up and down to form folds within the cavity  250 . Thus, a simple relative movement of the folding body  200  and the airbag  110  results in the desired folding of the airbag  110 .  
         [0020]     The size of the cavity  250  may be adapted for the size of the folds as well as the number of folds. Further, different sections of an airbag may be processed sequentially to fold a large airbag cushion.  
         [0021]      FIGS. 3 and 4  illustrate another embodiment of an airbag folding arrangement according to the invention. The arrangement  300  includes a lower comb body  310  and an upper comb body  320 . The lower comb body  310  is formed of a rigid stationary structure which includes a housing  312  having a cavity  313 . Support surfaces  314  are formed on each side of the cavity  313  to support the airbag  110 . One end of the airbag  110  is secured to the supporting surface  314  via a clamp or chuck  316 . Of course, numerous other alternative configurations may be provided to secure the airbag  110 .  
         [0022]     A plurality of comb blades  318  are provided within the cavity  313 . The comb blades  318  may be rigid structures affixed within the cavity extending substantially vertically from the housing  312 . The comb blades  318  are equally spaced apart, forming fold regions  319  therebetween.  
         [0023]     The upper comb body  320  includes a stationary housing  322  positioned substantially above the cavity  313  of the lower comb body  310 . A plurality of movable blades  324  are provided within the housing  322  of the upper comb body  320 .  
         [0024]     Each movable blade  324  is positioned substantially above a corresponding folding region  319  of the lower comb body  310 . The movable blades  324  are adapted to be moved vertically together or preferably independent of each other. Thus, each movable blade  324  may be independently controlled by a central controller, for example. The movement of the movable blades  324  may be achieved in numerous ways apparent to those skilled in the art. For example, the movement of the movable blades  324  may be facilitated by a motor adapted to translate each blade along a track formed at one end of the housing  322  for each track (not shown). In alternative embodiment the housing  322  may include an upper comb plate  326  that moves to force the blades into the airbag  110  and cavity  113 . The upper comb plates  326  may be configured to provide sequential folding of the airbag  110 .  
         [0025]      FIG. 4  illustrates the use of the arrangement  300  of  FIG. 3  for folding the airbag cushion  110 . With one end of the airbag  110  secured with the clamp  316 , the movable blade  324   a  closest to the fixed end of the airbag  110  is translated downward. The downward movement of the movable blade  324   a  extends the movable blade  324   a  into the corresponding folding region  319   a  between one side of the housing  312  and a fixed blade  318   a  of the lower comb body  310 . A fold of the airbag  110  is thus created within the folding region  319   a  corresponding to the movable blade  324   a.    
         [0026]     The creation of a fold naturally causes the airbag  110  to move toward the fold. Since one end of the airbag  110  is secured by the clamp  316 , the free end (not shown) of the airbag  110  moves toward the fold. Downward movement of other movable blades  324  of the upper comb body  320  in a sequential manner creates additional folds in each folding region  319  of the lower comb body  310 . The sequential manner proceeds from the movable blades  324  closest to the fixed end of the airbag  110  to those furthest from it.  
         [0027]     It is noted that, to prevent unfolding of folds, a movable blade  324  that has been moved downward to create a fold should remain in its lowered position at least until the next fold is created. For example, the first movable blade  324   a  should remain in the lowered position at least until the second movable blade  324   b  is moved into its lowered position. Otherwise, the downward movement of the second blade  324   b  may cause an unfolding of the fold created in the first folding region  319   a  by the first movable blade  324   a.    
         [0028]     In the embodiment illustrated in  FIG. 4 , the first movable blade  324   a  is completely in its lowered position, while the second movable blade  324   b  has remained in its fully raised position. It will be understood by those skilled in the art that, in order to enhance the speed of the folding process, the movement of the subsequent blades may be initiated before the completion of the movement of the earlier blades. Thus, the second movable blade  324   b  may be on its way to the lowered position before the first movable blade  324   a  has completed its translation. Furthermore, the earlier moving blades may remain lowered until all blades have been lowered. In an alternative embodiment, at least the adjacent blade remains lowered while the next blade creates a fold in the bag. Either of the aforementioned arrangements ensures that earlier created folds are not disturbed by later moving blades.  
         [0029]     The exemplary embodiment illustrated in  FIGS. 3 and 4  is provided with seven folding regions  319 . Of course, those skilled in the art will understand that other arrangements may be provided with any desired number of folding regions  319 . Further, in one embodiment, the lower comb body  310  may be provided with a larger number of folding regions  319 , while the upper comb body  320  may be provided with a smaller number of movable blades  324 . In this regard, the upper comb body  320  and the lower comb body  310  may be adapted to translate relative to each other to align the movable blades  324  with different folding regions  319 .  
         [0030]     As described above, the various embodiments of the present invention, provide several advantages such as, for example, a one-time “push in” folding operation. For example, a single translation of the scoop or upper comb plate will yield a folded airbag. Thus, the present invention provides for a short lead time, comfortable, efficient folding process. The embodiments of the present invention may be tailored or modified to produce different folding patterns as required for different modules or vehicles.  
         [0031]     Given the disclosure of the present invention, one versed in the art would appreciate that there may be other embodiments and modifications within the scope and spirit of the invention. Accordingly, all modifications attainable by one versed in the art from the present disclosure within the scope and spirit of the present invention are to be included as further embodiments of the present invention. The scope of the present invention is to be defined as set forth in the following claims.