Patent Publication Number: US-2005134025-A1

Title: Inflatable curtain

Description:
FIELD OF THE INVENTION  
      The present invention relates to an inflatable apparatus for helping to protect a vehicle occupant in the event of a side impact to the vehicle and/or a vehicle rollover.  
     BACKGROUND OF THE INVENTION  
      It is known to inflate an inflatable vehicle occupant protection device to help protect a vehicle occupant in the event of a vehicle collision. One particular type of inflatable vehicle occupant protection device is an inflatable curtain that inflates away from the roof of the vehicle downward inside the passenger compartment between a vehicle occupant and the side structure of the vehicle in the event of a side impact or rollover. A known inflatable curtain is inflated from a deflated condition by inflation fluid directed from an inflator to the inflatable curtain.  
     SUMMARY OF THE INVENTION  
      The present invention relates to an apparatus for helping to protect an occupant of a vehicle. The apparatus includes an inflatable curtain that is inflatable away from a vehicle roof of the vehicle to a position between a side structure of the vehicle and a vehicle occupant. The inflatable curtain has a length and includes opposite ends spaced apart along its length. The inflatable curtain includes a portion that overlies a B pillar of the vehicle. The inflatable curtain has a first portion that has a first vertical height and extends from adjacent the B pillar to one of the end portions. The inflatable curtain has a second portion that has a second vertical height and extends from adjacent the B pillar to the other of the end portions. The first and second vertical heights are different from each other.  
      The present invention also relates to an apparatus for helping to protect an occupant of a vehicle that has a side structure and a roof. The apparatus includes an inflatable curtain that is inflatable away from the vehicle roof to a position between the side structure of the vehicle and a vehicle occupant. The inflatable curtain has a front portion that extends forward in the vehicle from adjacent a B pillar of the vehicle. The inflatable curtain also includes a rear portion that extends rearward in the vehicle from adjacent the B pillar. The front portion has a first vertical height and the rear portion has a second vertical height. The first vertical height is greater than the second vertical height.  
      The present invention further relates to an apparatus for helping to protect an occupant of a vehicle that has a side structure and a roof. The apparatus includes an inflatable curtain that is inflatable away from the vehicle roof to a position between the side structure of the vehicle and a vehicle occupant. The inflatable curtain has a front portion extending forward in the vehicle from adjacent a B pillar of the vehicle and a rear portion extending rearward in the vehicle from adjacent the B pillar. The front portion has a first vertical height and the rear portion has a second vertical height that is greater than the first vertical height.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      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:  
       FIG. 1  is a schematic view of an apparatus for helping to protect a vehicle occupant illustrating the apparatus in a deflated condition in a vehicle, according to a first embodiment of the present invention;  
       FIG. 2  is a schematic view of the apparatus of  FIG. 1  in an inflated condition in the vehicle;  
       FIG. 3  is a schematic view of a portion of the apparatus of  FIGS. 1 and 2  in a non-inflated condition;  
       FIG. 4  is a schematic view illustrating the manufacture of the portion of  FIG. 3 ;  
       FIG. 5  is a schematic view of an apparatus for helping to protect a vehicle occupant illustrating the apparatus in an inflated condition in a vehicle, according to a second embodiment of the present invention; and  
       FIG. 6  is a schematic view of a portion of the apparatus of  FIG. 5  in a non-inflated condition.  
    
    
     DESCRIPTION OF EMBODIMENTS  
      Representative of the present invention, an apparatus  10  helps to protect an occupant of a vehicle  12 . As shown in  FIGS. 1 and 2 , the apparatus  10  includes an inflatable vehicle occupant protection device in the form of an inflatable curtain  14  that is mounted adjacent the side structure  16  of the vehicle  12  and the roof  18  of the vehicle. The side structure  16  of the vehicle  12  includes side windows  20 , an A pillar  30 , a B pillar  32 , and a C pillar  34 . An inflator  24  is connected in fluid communication with the inflatable curtain  14  through a fill tube  22 . The fill tube  22  may be constructed of any suitable material, such as metal, plastic, or fabric. Also, those skilled in the art will appreciate that the fill tube  22  may be omitted, in which case the inflator  24  may be connected directly to the inflatable curtain  14 .  
      The fill tube  22  has a first end portion  36  for receiving fluid from the inflator  24 . The fill tube  22  may be connected directly to the inflator  24  or a manifold (not shown) may connect the fill tube to the inflator. The fill tube  22  has a second end portion  38  disposed in the inflatable curtain  14 .  
      The inflator  24  contains a stored quantity of pressurized inflation fluid (not shown) in the form of a gas to inflate the inflatable curtain  14 . The inflator  24  alternatively could contain a combination of pressurized inflation fluid and ignitable material for heating the inflation fluid, or could be a pyrotechnic inflator that uses the combustion of gas-generating material to generate inflation fluid. As a further alternative, the inflator  24  could be of any suitable type or construction for supplying a medium for inflating the inflatable curtain  14 .  
      The apparatus  10  may include a housing  26  ( FIG. 1 ) that stores the inflatable curtain  14  in a stored and deflated condition. The fill tube  22 , the deflated inflatable curtain  14 , and the housing  26  have an elongated configuration and extend along the vehicle roof  18  and along the side structure  16  of the vehicle  12  above the side windows  20 . The fill tube  22 , inflatable curtain  14  and housing  26  are connected to the vehicle  12  by known means  28 , such as brackets.  
      Referring to  FIGS. 2 and 3 , the inflatable curtain  14  includes panels  40  of material that are arranged in an overlying manner. Overlapping portions of the panels are secured together by weaving the panels together along at least a portion of a perimeter  44  of the inflatable curtain  14  to form a perimeter connection  46  of the curtain. The perimeter connection  46  helps define an inflatable volume of the inflatable curtain  14 .  
      The inflatable curtain  14  may also include interior connections  50  in which the overlying panels  40  are interconnected within the perimeter  44  of the curtain. The interior connections  50  form non-inflatable portions of the inflatable curtain  14  within the perimeter  44  of the curtain. The interior connections  50  also help define inflatable chambers  52  of the inflatable curtain  14 . In the configuration of the inflatable curtain  14  illustrated in  FIG. 3 , one of the chambers  52 , identified at  54 , has a curved configuration and extends from forward of the B pillar  32  to rearward of the B pillar and covers a portion of the B pillar. One of the interior connections  50 , identified at  56 , forms a non-inflatable area positioned adjacent or near the B pillar  32 . The configuration of the interior connections  50 , and thus the chambers  52 , may vary depending on a variety of factors, such as the architecture of the vehicle  12 , the position of the inflatable curtain  14  in the vehicle, and the desired extent or coverage of the curtain.  
      The panels  40  are woven from a material, such as nylon yarn, and may be coated with a gas impermeable material, such as urethane, or laminated with a gas impermeable film. The inflatable curtain  14  thus may have a 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 inflatable curtain  14 .  
      The inflatable curtain  14  includes an upper edge  60 , an opposite lower edge  62 , and front and rear portions  64  and  66 , respectively, that extend between the upper and lower edges. The front portion  64  includes a front edge  70  of the inflatable curtain  14 . The rear portion  66  includes a rear edge  72  of the inflatable curtain  14 . The perimeter  44  of the inflatable curtain  14  is defined at least partially by the upper edge  60 , lower edge  62 , front edge  70 , and rear edge  72 . A front portion  100  of the lower edge  60  extends along the front portion  64  of the inflatable curtain  14 . A rear portion  102  of the lower edge  60  extends along the rear portion  66  of the inflatable curtain  14 .  
      In the embodiment illustrated in  FIG. 2 , the front and rear edges  70  and  72  extend between the upper and lower edges  60  and  62  and help define respective terminal end portions of the inflatable curtain  14 . Those skilled in the art, however, will appreciate that the inflatable curtain  14  may have a shape that differs from that of the curtain of the illustrated embodiment. For example, in the illustrated embodiment, the rear edge  72  could be omitted and the upper and lower edges  60  and  62  could be curved and extended until they intersect, in which case the rear portion  66  would be defined by the intersecting upper and lower edges.  
      The vehicle  12  includes a sensor mechanism  80  (shown schematically in  FIGS. 1 and 2 ) for sensing the occurrence of an event for which occupant protection is desired, such as a side impact to the vehicle  12  and/or a vehicle rollover. Upon sensing the occurrence of such an event, the sensor mechanism  80  provides an electrical signal over lead wires  82  to the inflator  24 . The electrical signal causes the inflator  24  to be actuated in a known manner. The inflator  24  discharges fluid under pressure through fill tube  22 , which directs the fluid into the inflatable curtain  14 .  
      The inflatable curtain  14  inflates under the pressure of the inflation fluid from the inflator  24 . The inflatable curtain  14  inflates away from the roof  18  in a downward direction as shown in the drawings and in a downward direction with respect to the direction of forward travel of the vehicle  12  into the position illustrated in  FIG. 2 .  
      The inflatable curtain  14 , when inflated, extends along the side structure  16  of the vehicle  12  and is positioned between the side structure and any occupant of the vehicle. The inflatable curtain  14  extends between the A pillar  30  and the C pillar  34  of the vehicle  12  and may overlie portions of the A pillar, C pillar, and the B pillar  32  of the vehicle. The front and rear portions  64  and  66  meet each other at a location adjacent or near the B pillar  32  of the vehicle  12 . The front portion  64  of the inflatable curtain  14  extends from adjacent or near the B pillar  32  to the front edge  70 , adjacent or near the A pillar  30 . The rear portion  66  of the inflatable curtain  14  extends from adjacent or near the B pillar  32  to the rear edge  72 , adjacent or near the C pillar  34 . The extents of the front and rear portions  64  and  66  could vary, depending on factors such as the architecture of the vehicle  12  and the desired vehicle coverage.  
      The inflatable curtain  14 , when inflated, helps to protect a vehicle occupant in the event of a vehicle rollover and/or a side impact to the vehicle  12 . The inflatable curtain  14 , when inflated, helps to absorb the energy of impacts with the curtain and helps to distribute the impact energy over a large area of the curtain.  
      According to the present invention, the inflatable curtain  14  has a stepped configuration in which the front and rear portions  64  and  66  of the curtain have different vertical heights. More specifically, in the embodiment of  FIGS. 1 and 2 , the front portion  64  has a vertical height that is greater than the vertical height of the rear portion  66 .  
      By “vertical height,” it is meant to describe the height of the front and rear portions  64  and  66  as measured vertically in  FIGS. 2 and 3 . Referring to  FIGS. 2 and 3 , it will be appreciated that the differential between the vertical heights of the front and rear portions  64  and  66  is effectuated through the stepped configuration of the lower edge  62  of the curtain  14 . These different vertical heights may be quantified in reference to a longitudinal axis  104  ( FIG. 3 ) of the inflatable curtain  14 .  
      When the inflatable curtain  14  is in the non-inflated and flattened condition of  FIG. 3 , the vertical height of the front portion  64  of the curtain may be quantified as a first distance, indicated at D 1 , from the axis  104  to the front portion  100  of the lower edge  62 . The vertical height of the rear portion  66  of the curtain may be quantified as a second distance, indicated at D 2 , from the axis  104  to the rear portion  102  of the lower edge  62 . The difference in these first and second distances D 1  and D 2  thus equals the difference in vertical height between the front and front and rear portions  64  and  66  of the inflatable curtain  14 . The difference in vertical height between the front and rear portions  64  and  66  may vary. For example, the difference in vertical height between the front and rear portions  64  and  66  may be 15% or more.  
      In the configuration of  FIG. 3 , the vertical heights of the front and rear portions  64  and  66  could be measured between the upper and lower edges  60  and  62 , since the upper and lower edges extend generally parallel to each other. Those skilled in the art, however, will appreciate that the upper and lower edges  60  and  62  may not be parallel. In this instance, measurement of the vertical heights from the axis  104  still yields an accurate depiction of the difference in vertical heights of the front and rear portions  60  and  62 .  
      Referring to  FIG. 3 , the upper edge  60  of the inflatable curtain  14  when in the non-inflated and flattened condition, extends generally parallel to the axis  104 . When installed in the vehicle  12  ( FIG. 2 ), however, the upper edge  60  is arranged along the curved configuration of the vehicle roof  18 . Because of this, when the inflatable curtain  14  is in the inflated condition, the rear portion  66  of the inflatable curtain  14  is positioned vertically downward relative to the front portion  64  of the curtain. As a result, the rear portion  102  of the lower edge  62  may have portions positioned at about the same vertical extent in the vehicle  12  as the front portion  100  of the lower edge.  
      The front and rear portions  64  and  66  of the inflatable curtain  14 , when inflated, may thus extend from adjacent or near the vehicle roof  18  down to a desired position along the side structure  16 . In the embodiment of  FIG. 2 , the front and rear portions  64  and  66  extend down to adjacent or below a belt line  110  of the vehicle  12 . The belt line  110  extends along the side structure  16  just below the side windows  20  along the area where interior trim (not shown) of the side structure, e.g., door panels, form a lower portion or sill of the side window openings.  
      The front portion  64  may thus cover a portion of the side structure  16  adjacent or below the belt line  110  that extends from adjacent or near the A pillar  30  to adjacent or near the B pillar  32 . The rear portion  66  may thus cover a portion of the side structure  16  adjacent or below the belt line  110  that extends from adjacent or near the B pillar  32  to adjacent or near the C pillar  34 . The stepped configuration of the lower edge  62  of the inflatable curtain  14  thus utilizes the architecture of the vehicle  12 , i.e., the curved roof  18 , to provide a desired amount of vehicle coverage.  
      According to one embodiment of the present invention, the inflatable curtain  14  of  FIGS. 2 and 3  may be woven on a loom in a continuous weaving process in which several curtains are woven simultaneously in a sheet and then cut out to separate the individual curtains.  FIG. 4  illustrates an example of multiple curtains  14  woven in a sheet  120 .  
      As shown in  FIG. 4 , the stepped configuration of the inflatable curtains  14  allows the curtains to be nested in rows  122  extending across a width of the sheet  120 . In this nested configuration, the curtains  14  are arranged in pairs with the lower edges  62  of each curtain in the pair being positioned adjacent to each other. The curtains  14  in each pair are arranged such that the front portion  64  of each curtain of the pair is positioned adjacent the rear portion  66  of the other curtain of the pair. Because of this, the curtains  14  in each pair may be positioned close to each other and the space provided by the shortened vertical height of the rear portions  66  may receive the front portions  64 . This helps to minimize the width of the sheet  120  required to accommodate a given number of curtains  14  in a row  122 . Conversely, for a sheet  120  having a given width, this may help maximize the number of curtains  14  that may be woven in a given row  122 .  
      For example, for the configuration of the inflatable curtain  14  of  FIG. 3 , the vertical height of the curtain may measure about 615 millimeters from the upper edge  60  to the lower edge  62  in the front portion  64  of the curtain. In the rear portion  66  of the curtain  14 , the vertical height may measure about 515 millimeters from the upper edge  60  to the lower edge  62 .  
      To produce the curtains  14  in rows  122  of four without nesting the curtains as shown in  FIG. 4 , the width of the sheet  120  would need to be at least about 4×615 millimeters, i.e., 2460 millimeters. This does not take into account providing spacing between the individual curtains  14  in the rows  122  to facilitate cutting the curtains from the woven sheet  120 . Allowing 10 millimeters spacing along the upper and lower edges  60  and  62  of each curtain  14  to facilitate cutting out the curtains would increase the required width of the sheet  120  to about 2540 millimeters.  
      The difference in vertical height between the front and rear portions  64  and  66  is about 100 millimeters. Thus, producing the curtains  14  in rows  122  of four while nesting the curtains as shown in  FIG. 4  may reduce the width of the sheet  120  by about 100 millimeters for each nested pair of curtains in the row. Allowing 10 millimeters spacing along the upper and lower edges  60  and  62  of each curtain  14  to facilitate cutting out the curtains would result in the sheet  120  having a width of about 2340 millimeters.  
      The reduction in width of the sheet  120  facilitated by the stepped configuration of the inflatable curtain  14  may thus provide a reduction in material (i.e., yarn) of about 8.2% over weaving in rows  122  of four without nesting. This may also reduce the amounts of other materials, such as coatings and laminates, that are required to manufacture the curtains  14 . Producing the curtains  14  in nested rows  122  thus may provide a cost savings over producing the curtains in non-nested rows.  
      Those skilled in the art will appreciate that manufacturing equipment, such as looms, scouring machines, cutting machines, and lamination and coating machines may limit the width of the sheet  120  to a width that the respective machines are capable of processing. For some of this equipment, this limit in sheet width may fall at about 2500 millimeters. For the example dimensions given above, the non-nested curtains would exceed this limit. In this instance, the curtains  14  cannot be produced in rows of four, which would dictate that the curtains be produced in rows of three. If produced in the nested configuration of  FIG. 4 , however, the curtains  14  can be produced in rows of four and fall well within the 2500 millimeter width limit for the sheet.  
      It will thus be appreciated that, through the stepped curtain configuration of the present invention, the inflatable curtain  14  may be produced in rows of four instead of rows of three, which would amount to a 33% increase in the number of curtains produced per unit length of the sheet. The processing costs, i.e., the non-material costs associated with warping, sizing, weaving, scouring, and applying lamination or sealant remain about the same regardless of whether the curtains are produced in rows of three or four. The incremental costs associated with producing the curtains in rows of four as opposed to rows of three may be limited to material costs and cutting costs. As a result, the stepped configuration of the inflatable curtain  14  thus may help reduce manufacturing costs of the curtain on a cost per curtain basis.  
      A second embodiment of the present invention is illustrated in  FIGS. 5 and 6 . The second embodiment of the present invention is similar to the first embodiment of the invention illustrated in  FIGS. 1-4 . Accordingly, reference numbers similar to those of  FIGS. 1-4  will be utilized in  FIGS. 5 and 6 , the suffix letter “a” being associated with the reference numbers of  FIGS. 5 and 6  to avoid confusion.  
      As shown in  FIGS. 5 and 6 , inflatable curtain  14   a  has a stepped configuration in which the front and rear portions  64   a  and  66   a  of the inflatable curtain have different vertical heights. More specifically, in the embodiment of  FIGS. 5 and 6 , the rear portion  66   a  has a vertical height that is greater than the vertical height of the front portion  64   a.    
      By “vertical height,” it is meant to describe the height of the front and rear portions  64   a  and  66   a  as measured vertically in  FIGS. 5 and 6 . Referring to  FIGS. 5 and 6 , it will be appreciated that the differential between the vertical heights of the front and rear portions  64   a  and  66   a  is effectuated through the stepped configuration of the lower edge  62   a  of the curtain  14   a.  These different vertical heights may be quantified in reference to a longitudinal axis  104   a  ( FIG. 6 ) of the inflatable curtain  14   a.    
      When the inflatable curtain  14   a  is in the non-inflated and flattened condition of  FIG. 6 , the vertical height of the front portion  64   a  of the curtain may be quantified as a third distance, indicated at D 3 , from the axis  104   a  to the front portion  100   a  of the lower edge  62   a.  The vertical height of the rear portion  66   a  of the curtain may be quantified as a fourth distance, indicated at D 4 , from the axis  104   a  to the rear portion  102   a  of the lower edge  62   a.  The difference in these third and fourth distances D 3  and D 4  thus equals the difference in vertical height between the front and front and rear portions  64   a  and  66   a  of the inflatable curtain  14   a.  The difference in vertical height between the front and rear portions  64   a  and  66   a  may vary. For example, the difference in vertical height between the front and rear portions  64   a  and  66   a  may be 15% or more.  
      Referring to  FIGS. 5 and 6 , the inflatable curtain  14   a  includes an interior connection  50   a,  identified at  150 , that helps define a lower chamber  152  of the rear portion  66   a  of the curtain. The lower chamber  152  may be positioned entirely below the front portion  100   a  of the lower edge  62   a  when the inflatable curtain  14   a  is in the inflated condition of  FIG. 5 . The connection  150  also helps define a passage  154  for directing inflation fluid from the other chambers  52   a  of the inflatable curtain  14   a  into the chamber  152 . Since the lower chamber  152  forms the lowermost inflatable portion of the inflatable curtain  14   a,  the lower chamber may begin inflating after the remaining chambers  52   a  of the curtain begin inflating.  
      When the inflatable curtain  14   a  is in the inflated condition of  FIG. 5 , the upper edge  60   a  is positioned adjacent the vehicle roof  18   a.  The lower edge  62   a  is positioned below the belt line  110   a  of the vehicle  12   a.  The front edge  70   a  is positioned adjacent the A pillar  30   a.  The rear edge  72   a  is positioned adjacent the C pillar  34   a.    
      The front portion  64   a  of the inflatable curtain  14   a,  when inflated, extends from adjacent or near the vehicle roof  18   a  down to below the belt line  110   a  of the vehicle  12   a.  The front portion  64   a  may thus cover a portion of the side structure  16   a  below the belt line  110   a  that extends from adjacent or near the A pillar  30   a  to adjacent or near the B pillar  32   a.    
      The rear portion  66   a  of the inflatable curtain  14   a,  when inflated, extends from adjacent or near the vehicle roof  18   a  down to below the belt line  110   a  of the vehicle  12   a.  Because the upper edge  60   a  is arranged along a curved portion of the vehicle roof  18   a,  the rear portion  66   a  may extend further downward when the inflatable curtain  14   a  is in the inflated condition. The rear portion  66   a,  particularly the lower chamber  152 , may thus cover a portion of the side structure  16   a  below the belt line  110   a  that extends from adjacent or near the B pillar  32   a  to adjacent or near the C pillar  34   a.  The lower chamber  152 , extending below the belt line  110   a,  may have an inflated position adjacent the head and/or torso of a small occupant, such as a child (not shown) occupying a rear vehicle seat.  
      It will thus be appreciated that the stepped configuration of the inflatable curtain  14   a  of the second embodiment helps provide extended coverage below the belt line  110   a  in the rear portion  66   a  of the curtain. It will also be appreciated that, through the stepped curtain configuration, the inflatable curtain  14   a  may be manufactured in sheets with multiple curtains nested together in rows, as described above in regard to the first embodiment ( FIGS. 1-4 ). The stepped configuration of the inflatable curtain  14   a  of the second embodiment ( FIGS. 5 and 6 ) may thus provide manufacturing cost savings similar to those described above in regard to the first embodiment.  
      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.