Abstract:
An inflatable vehicle occupant protection device ( 14 ) includes a vertically extending central recess ( 200 ) and first and second lobes ( 202  and  204 ) positioned on opposite sides of the central recess. The central recess ( 200 ) and the first and second lobes ( 202  and  204 ) are defined at least partially by an elongated center panel ( 210 ) of the protection device ( 14 ). The center panel ( 210 ) includes first and second longitudinal edges ( 250  and  252 ) that are spaced apart from each other and that extend along the length of opposite edge portions of the center panel. The center panel ( 210 ) also includes first and second end portions ( 260  and  280 ) that are spaced apart and that are positioned opposite each other along the length of the center panel. The center panel ( 210 ) is arranged in a loop, and a portion ( 270 ) of the first longitudinal edge ( 252 ) along the first end portion ( 260 ) is interconnected with a portion ( 290 ) of the second longitudinal edge ( 250 ) along the second end portion ( 280 ) of the panel to form a vertically extending seam ( 220 ) that helps define the central recess.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 61/134,884, filed on Jul. 14, 2008. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to an apparatus for helping to protect an occupant of a vehicle. More particularly, the present invention relates to an air bag inflatable between an instrument panel and a front seat occupant of a vehicle. 
       BACKGROUND OF THE INVENTION 
       [0003]    It is known to provide an inflatable vehicle occupant protection device, such as an air bag, for helping to protect an occupant of a vehicle. One particular type of air bag is a frontal air bag inflatable between an occupant of a front seat of the vehicle and an instrument panel of the vehicle. Such air bags may be driver air bags or passenger air bags. When inflated, the driver and passenger air bags help protect the occupant from impacts with parts of the vehicle such as the instrument panel and/or a steering wheel of the vehicle. 
         [0004]    Passenger air bags are typically stored in a deflated condition in a housing that is mounted to the vehicle instrument panel. An air bag door is connectable with the housing and/or instrument panel to help enclose and conceal the air bag in a stored condition. Upon deployment of the passenger air bag, the air bag door opens to permit the air bag to move to an inflated position. The air bag door opens as a result of forces exerted on the door by the inflating air bag. 
         [0005]    Driver air bags are typically stored in a deflated condition in a housing that is mounted on the vehicle steering wheel. An air bag cover is connectable with the housing and/or steering wheel to help enclose and conceal the air bag in a stored condition. Upon deployment of the driver air bag, the air bag cover opens to permit the air bag to move to an inflated position. The air bag cover opens as a result of forces exerted on the cover by the inflating driver air bag. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention relates to an apparatus for helping to protect an occupant of a vehicle. The apparatus includes an inflatable vehicle occupant protection device having a deflated condition and an inflated condition. 
         [0007]    The air bag has a bi-lobular design in which first and second lobes are defined by a recess positioned between the lobes. The air bag has a construction in which the lobes are defined by a single piece of material that is cut in a pattern and has portions interconnected to create the lobes. 
         [0008]    The present invention also relates to an inflatable vehicle occupant protection device for being inflated between an occupant of the vehicle and an instrument panel of the vehicle. The protection device includes a vertically extending central recess and first and second lobes positioned on opposite sides of the central recess. The central recess and the first and second lobes are defined at least partially by an elongated center panel of the protection device. The center panel includes first and second longitudinal edges that are spaced apart from each other and that extend along the length of opposite edge portions of the center panel. The center panel also includes first and second end portions that are spaced apart and that are positioned opposite each other along the length of the center panel. The center panel is arranged in a loop, and a portion of the first longitudinal edge along the first end portion is interconnected with a portion of the second longitudinal edge along the second end portion of the panel to form a vertically extending seam that helps define the central recess. 
         [0009]    The present invention further relates to an inflatable vehicle occupant protection device including a vertically extending central recess and first and second lobes positioned on opposite sides of the central recess. The protection device includes an elongated center panel that has a generally S-shaped configuration with a first curved end portion curved outwardly in a first direction with respect to a length of the center panel. A second curved end portion, opposite the first curved end portion, is curved outwardly in a second direction, opposite the first direction, with respect to a length of the center panel. The center panel is arranged in a loop, and a first inner curved edge of the first curved end portion is connected with a second inner curved edge of the second curved end portion, the connection between the first and second inner curved edges defining the central recess. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The foregoing and other features of the present invention will become apparent to one skilled in the art to which the present invention relates upon consideration of the following description of the invention with reference to the accompanying drawings, in which: 
           [0011]      FIG. 1  is a schematic side view illustrating an apparatus for helping to protect an occupant of a vehicle including a bi-lobular air bag, according to a first embodiment of the present invention; 
           [0012]      FIG. 2  is a front view of an embodiment of a bi-lobular air bag in accordance with the present invention in an inflated condition; 
           [0013]      FIGS. 3A-3C  are views illustrating an embodiment of a bi-lobular air bag in accordance with the present invention in an inflated condition; 
           [0014]      FIG. 4A  is a schematic view illustrating a front view of a bi-lobular air bag in accordance with the present invention; 
           [0015]      FIG. 4B  is a sectional view bag taken generally along line  4 B- 4 B in  FIG. 4A ; 
           [0016]      FIG. 5  is a plan view illustrating a center panel of a bi-lobular air bag in accordance with the present invention; 
           [0017]      FIG. 6  is a plan view illustrating portions of a bi-lobular air bag laid out on a sheet for cutting into individual parts in accordance with the present invention; 
           [0018]      FIG. 7  is a front view of an embodiment of a bi-lobular air bag in accordance with the present invention in an inflated condition and illustrating certain dimensions; 
           [0019]      FIGS. 8A and 8B  are front and side views, respectively, of an embodiment of a bi-lobular air bag in accordance with the present invention in an inflated condition and illustrating certain dimensions; 
           [0020]      FIGS. 9A and 9B  are front and side views, respectively, of another embodiment of a bi-lobular air bag in accordance with the present invention in an inflated condition and illustrating certain dimensions; 
           [0021]      FIGS. 10A and 10B  are front and side views, respectively, of a further embodiment of a bi-lobular air bag in accordance with the present invention in an inflated condition and illustrating certain dimensions; 
           [0022]      FIGS. 11A-11C  illustrate an embodiment of a bi-lobular air bag in accordance with the present invention in an inflated condition in a vehicle; 
           [0023]      FIG. 12  is a plan view illustrating portions of a bi-lobular air bag laid out on a sheet for cutting into individual parts in accordance with another embodiment of the present invention; and 
           [0024]      FIG. 13  is a side view illustrating an air bag constructed from the parts illustrated in  FIG. 12 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0025]    An apparatus  10  for helping to protect an occupant  20  of a vehicle  12  includes an inflatable vehicle occupant protection device  14  in the form of an air bag. In the embodiment illustrated in  FIG. 1 , the air bag  14  is a passenger frontal air bag for helping to protect an occupant  20  of a seat  22  on a passenger side  24  of the vehicle  12 . Those skilled in the art will appreciate that the apparatus  10  disclosed herein could be adapted for a driver side vehicle occupant (not shown) or occupants of rearward rows of the vehicle  12 , such as a 2 nd  row, 3 rd  row, etc., of the vehicle (not shown). 
         [0026]    The air bag  14  may be part of an air bag module  30  that includes an inflator  32  and a housing  34 . The air bag  14  has a stored condition, indicated by dashed lines in  FIG. 1 , in which the air bag is folded and placed in the housing  34 . The module  30  is mounted to a dash or instrument panel  36  of the vehicle  12 . The housing  34  helps contain and support the air bag  14  and inflator  32  in the instrument panel  36 . 
         [0027]    An air bag door  40  is releasably connected to the instrument panel  36  and/or the housing  34 . In a closed condition (not shown), the air bag door  40  forms a cover for the module  30  and helps enclose the air bag  14  in the stored condition in the housing  34 . The door  40  is movable to an opened condition illustrated in  FIG. 1  to uncover an opening  44  through which the air bag  14  may be deployed from the stored condition in the housing  34 . The door  40  may be connected to the vehicle  12 , e.g., the instrument panel  36 , either directly or through the housing  34 , by means (not shown), such as a plastic hinge portion, a strap, or a tether. 
         [0028]    The inflator  32  is actuatable to provide inflation fluid to an inflatable volume  54  of the air bag  14  to deploy the air bag to the inflated condition. The inflator  32  may be of any known type, such as stored gas, solid propellant, augmented, or hybrid. The apparatus  10  includes a sensor, illustrated schematically at  50 , for sensing an event for which inflation of the air bag  14  is desired, such as a collision. The inflator  32  is operatively connected to the sensor  50  via lead wires  52 . 
         [0029]    The air bag  14  can be constructed of any suitable material, such as nylon (e.g., woven nylon 6-6 yarns), and may be constructed in any suitable manner. For example, the air bag  14  may include one or more pieces or panels of material. If more than one piece or panel is used, the pieces or panels may be interconnected by known means, such as stitching, ultrasonic welding, heat bonding, or adhesives, to form the air bag. The air bag  14  may be uncoated, coated with a material, such as a gas impermeable urethane, or laminated with a material, such as a gas impermeable film. The air bag  14  thus may have a gas-tight or substantially gas-tight construction. Those skilled in the art will appreciate that alternative materials, such as polyester yarn, and alternatives coatings, such as silicone, may also be used to construct the air bag  14 . 
         [0030]    The air bag  14  may have one or more actuatable features for helping to control or tailor inflation of the air bag in response to vehicle conditions, occupant conditions, or both. These features may be actuatable actively, for example, in response to conditions determined via active sensors, or passively, for example, having a configuration responsive to physical conditions at the time of inflation. 
         [0031]    In the embodiment of  FIG. 1 , the air bag  14  includes a vent  100  that is selectively actuatable to release inflation fluid from the inflatable volume  54  of the air bag  14 . The vent  100  may have various configurations. In the embodiment illustrated in  FIG. 1 , the vent  100  includes one or more vent openings  102  formed in a side panel  104  of the air bag  14 , a vent door  110  secured to the side panel, and a flexible elongated member  112 , such as a tether, secured to the door panel. 
         [0032]    The vent door  110  is secured to the side panel  104  by known means (not shown), such as stitching, ultrasonic welding, heat bonding, or adhesives. The vent  100  has an open condition in which the vent door  110  is positioned away from the vent openings  102  and thereby permits inflation fluid to vent, i.e., flow, through the vent openings. In the open condition, the vent door  110  is folded away from the vent openings  102  and held in place by a releasable tear stitch. The tether  112  has a first end portion secured to the vent door  110  and an opposite second end portion secured to the air bag  14 . 
         [0033]    Upon sensing the occurrence of an event for which inflation of the air bag  14  is desired, such as a vehicle collision, the sensor  50  provides a signal to the inflator  32  via the lead wires  52 . Upon receiving the signal from the sensor  50 , the inflator  32  is actuated and provides inflation fluid to the inflatable volume  54  of the air bag  14  in a known manner. The inflating air bag  14  exerts a force on the door  40 , which moves the door to the opened condition. The air bag  14  inflates from the stored condition to a deployed condition, such as the fully inflated and deployed condition illustrated in solid lines in  FIG. 1 . The air bag  14 , while inflated, helps protect the vehicle occupant  20  from impacts with parts of the vehicle  12 , such as the instrument panel  36 . 
         [0034]    When an event occurs which inflation of the air bag  14  is desired, the vent  100  responds to vehicle conditions, occupant conditions, or both to help control inflation and deployment of the air bag. For example, the air bag  14  may be constructed such that the vent  100  is actuated in response to unobstructed deployment of the air bag  14  when the occupant is in a normally seated position. In this configuration, the air bag  14  may also be constructed to block actuation of the vent  100  in response to the obstructed deployment of the air bag  14  when, for example, the occupant is away from the normally seated position. 
         [0035]    Referring to  FIG. 2 , The air bag  14  includes a center panel  210 , a first side panel  212  that forms a left side of the air bag, and a second side panel  214  that forms a right side of the air bag. The panels  210 ,  212 , and  214  are interconnected by means, such as stitching, to define the structure of the air bag  14 . In the embodiment of  FIG. 2 , central stitching  220  interconnects portions of the center panel  210  to define the recess  200 . First side stitching  222  connects the first side panel  212  to the center panel  210 . Second side stitching  224  connects the second side panel  214  to the center panel  210 . The air bag  14  includes a central recess  200 , a first lobe  202  positioned to the left of the recess as viewed in  FIG. 2 , and a second lobe  204  positioned to the right of the recess as viewed in  FIG. 3 . 
         [0036]      FIGS. 3A-3C  illustrate front, top, and bottom views, respectively, of the air bag  14  in an inflated condition.  FIG. 4A  illustrates the air bag  14  schematically with a sectional view taken generally along line  4 B- 4 B illustrated in  FIG. 4B . As can be seen in these figures, the stitching  220  interconnecting portions of the center panel  210  to help define the recess  200 , first lobe  202 , and second lobe  204  has a generally curved and S-shaped configuration as viewed vertically from top to bottom in  FIGS. 3A-3C . 
         [0037]      FIGS. 5 and 6  illustrate schematically components used to construct an air bag  14  in accordance with one embodiment of the present invention. As shown in  FIG. 5 , the center panel  210  may have a one piece construction. As shown in  FIG. 6 , the center panel  210  may have a two piece construction.  FIG. 6  illustrates how components used to construct the air bag  14  may be cut from a single piece or sheet  218  of material. As shown in  FIG. 6 , the two piece design of the center panel may help provide better nesting and thereby help reduce material costs. 
         [0038]    As shown in  FIG. 6 , the components may include the center panel  210 , side panels  212  and  214 , first and second vent door panels  230  and  232 , respectively, and first and second vent tethers  234  and  236 , respectively. The side panels  212  and  214  include vent openings  240  that correspond with openings  242  in the vent door panels  230  and  232 . The center panel  210  may have various openings  244  for accommodating connection with the air bag module and the inflator. 
         [0039]    Referring to  FIG. 5 , the center panel  210  includes first and second edge portions  250  and  252 , respectively, that extend parallel to each other and help define the portions of the center panel connected to the first and second side panels  212  and  214 . The edge portions  250  and  252  define a central portion  254  of the center panel  210 . The central portion  254  has a generally rectangular configuration. 
         [0040]    First and second end portions  260  and  280 , respectively, extend from opposite ends of the central portion  254  of the center panel  210 . The first and second end portions  260  and  280  have generally curved configurations and, as shown in  FIG. 5 , may have dimensions that are identical to each other. The first end portion  260  curves generally downward and to the left from a first end  256  of the central portion  254 . The second end portion  280  curves generally downward and to the right from a second end  258  of the central portion  254 . The first and second end portions  260  and  280  have widths about equal to one-half the width, indicated generally at W in  FIG. 5 , of the central portion  254 . 
         [0041]    The first end portion  260  has an outer edge  262  that extends from the first edge portion  250  of the center panel  210  and an inner edge  270  that extends from the second edge portion  252  of the center panel. The outer and inner edges  262  and  270  have portions delineated by hash marks in  FIG. 5 . The outer edge  262  includes a curved portion  264  that curves generally downward and to the left as viewed in  FIG. 5  and a straight terminal second portion  266  that extends generally vertically as viewed in  FIG. 5 . 
         [0042]    The inner edge  270  includes a first portion  272  that extends generally upward and to the left from an intersection point  278  with the second edge portion  252 . A second curved portion  274  extends from the first curved portion  272  downward and to the left. A third curved portion  276  extends from the second curved portion  274  downward and to the left along a curvature opposite or reversed from the first and second curved portions  272  and  274 . The third curved portion  276  terminates in an intersection with the second portion  266  of the outer edge  260  at a terminal end point  268 . 
         [0043]    The second end portion  280  has an outer edge  282  that extends from the second edge portion  252  of the center panel  210  and an inner edge  290  that extends from the first edge portion  250  of the center panel. The outer and inner edges  282  and  290  have portions delineated by hash marks in  FIG. 5 . The outer edge  282  includes a curved portion  284  that curves generally upward and to the right as viewed in  FIG. 5  and a straight terminal second portion  286  that extends generally vertically as viewed in  FIG. 5 . 
         [0044]    The inner edge  290  includes a first portion  292  that extends generally downward and to the right from an intersection point  298  with the first edge portion  250 . A second curved portion  294  extends from the first curved portion  292  upward and to the right. A third curved portion  296  extends from the second curved portion  294  upward and to the right along a curvature opposite or reversed from the first and second curved portions  292  and  294 . The third curved portion  296  terminates in an intersection with the second portion  286  of the outer edge  280  at a terminal end point  288 . 
         [0045]    To construct the air bag  14 , the center panel  210  is looped and the first and second end portions  260  and  280  are interconnected by the central stitching  220 . According to the present invention, the inner edge  270  of the first end portion  260  and the inner edge  290  of the second end portion  280  are configured to mate with each other and, when interconnected, place the center panel  210  in the form of a loop and form the recess  200 . To accomplish this, the edges of the first and second end portions  260  and  280  are interconnected as follows: 
         [0046]    1.) The first portion  272  of the inner edge portion  270  of the first end portion  260  is connected to the third portion  296  of the inner edge portion  290  of the second end portion  280 . 
         [0047]    2.) The second portion  274  of the inner edge portion  270  of the first end portion  260  is connected to the second portion  294  of the inner edge portion  290  of the second end portion  280 . 
         [0048]    3.) The third portion  276  of the inner edge portion  270  of the first end portion  260  is connected to the first portion  292  of the inner edge portion  290  of the second end portion  280 . 
         [0049]    As can be seen from the above, this places the terminal end point  268  of the first end portion  260  at the intersection point  298  of the second end portion  280 . The outer edge  262  and the upper edge  250  thus form an endless loop when the inner edges  270  and  290  are interconnected by the central stitching  220 . Similarly, this places the terminal end point  288  of the second end portion  280  at the intersection point  278  of the first end portion  260 . The outer edge  282  and the lower edge  252  thus form an endless loop when the inner edges  270  and  290  are interconnected by the central stitching  220 . 
         [0050]    To continue construction of the air bag  14 , the first side panel  212  is connected to the center panel  210  via the first side stitching  222  along the looped edge formed by the outer edge  262  and upper edge  250 . The second side panel  214  is connected to the center panel  210  via the second side stitching  224  along the looped edge formed by the outer edge  282  and lower edge  252 . If the air bag  14  includes vents  100 , the vent door panels  230  and  232 , and the tethers  234  and  236 , may be connected to the side panels  212  and  214  prior to connecting the side panels to the center panel  210 . 
         [0051]    The air bag  14 , constructed in this manner, includes the central recess  200 , first lobe  202 , and second lobe  204 . Those skilled in the art will appreciate that, according to the present invention, the configuration of the central recess  200  and, thus, the lobes  202  and  204 , depends on the relation between the inner radius R in  of the second portions  274  and  294  of the inside edges  270  and  290  and the outer radius R out  of the first portions  264  and  284  of the outside edges  262  and  282 . By changing the difference between R in  and R out , the arc angle of the center panel and the depth of the central recess  200  can be controlled to desired dimensions. The larger the difference the deeper the recess  200 . This is illustrated in various example embodiments shown in  FIGS. 7-10B : 
       Embodiment of FIG.  7   
       [0052]    Volume: 108 liters 
         [0053]    Width (E): 545 mm 
         [0054]    Height (D): 480 mm 
         [0055]    Depth @ top (A): 55 mm 
         [0056]    Depth @ center (B): 20 mm 
         [0057]    Depth @ bottom (C): 25 mm 
       Embodiment of FIGS.  8 A &amp;  8 B 
       [0058]    Width (E): 540 mm 
         [0059]    Height (D): 570 mm 
         [0060]    Depth @ top (A): 70 mm 
         [0061]    Depth @ center (B): 50 mm 
         [0062]    Depth @ bottom (C): 150 mm 
       Embodiment of FIGS.  9 A &amp;  9 B 
       [0063]    R in :  300   
         [0064]    R out :  540   
         [0065]    Arc Angle: 162 degrees 
         [0066]    Volume: 110 liters 
         [0067]    Width (E): 550 mm 
         [0068]    Height (D): 545 mm 
         [0069]    Depth @ top (A): 130 mm 
         [0070]    Depth @ center (B): 40 mm 
         [0071]    Depth @ bottom (C): 65 mm 
       Embodiment of FIGS.  10 A &amp;  10 B 
       [0072]    R in :  272   
         [0073]    R out :  512   
         [0074]    Arc Angle: 154 degrees 
         [0075]    Volume: 110 liters 
         [0076]    Width (E): 540 mm 
         [0077]    Height (D): 550 mm 
         [0078]    Depth @ top (A): 110 mm 
         [0079]    Depth @ center (B): 40 mm 
         [0080]    Depth @ bottom (C): 60 mm 
         [0081]    Deployment of the air bag  14  is illustrated in  FIGS. 11A-11C . As shown in  FIGS. 11A-11C , the central recess  200  of the bi-lobular air bag  14  provides relief for the head. This shape bag can also help support the occupant&#39;s head for angular impacts. The recess  200  provides an area in the bag where the occupant&#39;s head fits to minimize bag interaction. This shape causes the bag to load more on the shoulders than the head. The location of the indentation can be moved or extended to the bottom of the bag to also provide a “pocket” for an infant&#39;s head in a rear facing infant seat. 
         [0082]      FIG. 12  illustrates an alternative construction of the air bag. As shown in  FIG. 12 , the center panel  210 ′ may have a two piece construction.  FIG. 12  illustrates how components used to construct the air bag may be cut from a single piece or sheet  218 ′ of material. As shown in  FIG. 12 , the two piece design of the center  210 ′ panel may help provide better nesting and thereby help reduce material costs. 
         [0083]    As shown in  FIG. 12 , the components may include the center panel  210 ′, side panels  212 ′ and  214 ′, first and second vent door panels  230 ′ and  232 ′, respectively, and first and second vent tethers  234 ′ and  236 ′, respectively. The side panels  212 ′ and  214 ′ include vent openings  240 ′ that correspond with openings  242 ′ in the vent door panels  230 ′ and  232 ′. The center panel  210 ′ may have various openings  244 ′ for accommodating connection with the air bag module and the inflator. 
         [0084]    As shown in  FIG. 12 , the two piece design includes center panel component piece  300  and  302 . The center panel components  300  has an end portion  302  with a terminal edge  304 . The center panel component  310  has an end portion  312  with a terminal edge  314 . The end portions  302  and  312  have an outwardly flared configuration and the terminal edges  304  and  314  have curved configurations. 
         [0085]    Referring to  FIG. 13 , stitching  320  interconnects the end portions  302  and  312  along the terminal edges  304  and  314 . According to the present invention and, as illustrated in  FIG. 13 , the outwardly flared configuration of the end portions  302  and  312  in combination with the curved configuration of the terminal edges  304  and  314  help tailor the overall configuration of the air bag  14 ′. As shown in  FIG. 13 , the curved configuration of the terminal edges  304  and  314  provides a rearward region  322  of the air bag  14 ′ with a narrowly tapered shape that may, for example, help position that portion of the air bag in the space between the windshield and instrument panel of the vehicle. Also, the outwardly flared configuration of the end portions  302  and  312  helps provide a large radius (illustrated generally at R in  FIG. 13 ) connection between the center panel  210 ′ and the side panel  212 ′. This can help make it easier to stitch the side panel  212 ′ to the center panel  210 ′ and this facilitates assembly of the air bag  14 ′. 
         [0086]    From the above description of the invention, those skilled in the art will perceive improvements, changes and modifications. Such improvements, changes and modifications within the skill of the art are intended to be covered by the appended claims.