Abstract:
A bottom fill airbag that is adapted so that inflation gas is channeled to the bottom of the airbag, causing the bottom portion of the airbag to initially inflate, then subsequently and progressively filling the entire airbag chambers from the lower portions upward to the top of the airbag. The bottom fill side airbag may include one or a plurality of channels that direct inflation gas from an inflator down to lower portions of the airbag. The inflation gas subsequently and progressively fills airbag chambers, starting from the bottom of the airbag and moving upwards inside of the airbag.

Description:
BACKGROUND  
       [0001]     The present invention relates to a protective, bottom filled side airbag for protection of a vehicle occupant&#39;s head and, more particularly, to an airbag which is to be inflated to expand over windows of side doors in the event of a lateral collision or roll-over of a vehicle.  
         [0002]     An airbag for the protection of a vehicle occupant&#39;s head may be disposed along a corner formed by a roof and a side portion of a vehicle cabin in the normal state and is adapted to be inflated with gas introduced through gas inlets to expand over windows of side doors.  
         [0003]     Most of such head protective airbags are of a type which is disposed from an A-pillar along a roof side rail. Among the head protective airbags, there is a type not to allow the inflation of a portion along the A-pillar and a type to allow the inflation of a portion along the A-pillar. The present invention relates to a head protective airbag of a type to allow a portion along the A-pillar to be inflated just like the latter type and to a head protective airbag device with the head protective airbag.  
         [0004]     In a conventional head protective airbag which is adapted to allow the inflation of a portion along a pillar, the airbag starts to be inflated within the cover and pushes and opens the cover, whereby the airbag deploys into the vehicle cabin. Therefore, the cover must have a large enough opening to allow the deployment of the already expanding airbag.  
         [0005]     The present invention relates to a bottom filled side airbag for protecting vehicle occupants during collisions and rollover accidents.  
         [0006]     In a conventional side airbag, the airbag is typically deployed from the headliner of a vehicle. The airbag, or cushion, is typically rolled and/or folded into a compact package that is stored in the headliner area. The airbag is pressurized during deployment and forced out of the containment area into an operating position. In conventional designs, the inflator typically directs an inflation gas directly into upper sections of the airbag, thereby filling the cushion from the top down.  
         [0007]     This fill process pushes the airbag down into an operating position. This design tends to deploy from headliners and present a large volume envelope that descends downward along the interior side or interior surface of the vehicle until the airbag is fully inflated. If an occupant&#39;s head is near, or in contact with, the vehicle interior surface or structure, the large volume of the deploying airbag will seek to occupy the same position and in effect push downward on the occupant&#39;s head during deployment.  
       SUMMARY  
       [0008]     It is an object of the present invention to provide a head protective airbag which is adapted to allow the inflation of a portion along a pillar, but not to allow or scarcely allow the inflation before it is pulled or dragged out of a pillar cover, whereby the portion can be extremely smoothly dragged out of the pillar cover and to provide a head protective airbag device provided with the airbag.  
         [0009]     According to an embodiment of the present invention, a head protective airbag is a head protective airbag to be disposed to extend along at least one pillar and a roof side rail, comprising one or more first cell extending along the pillar, and one or more second cell extending along the roof side rail, wherein a passage for introducing gas into the first cell is connected to the first cell only at a portion opposite to the pillar side of the first cell.  
         [0010]     In addition, a head protective airbag device of the present invention may include the above head protective airbag and a gas supply device for supplying gas into the head protective airbag.  
         [0011]     According to an embodiment of the present invention, a head protective airbag and airbag device has gas introduced into the airbag to inflate the airbag, wherein introduction of gas into a first cell extending along a pillar is conducted only through a gas passage connected to the portion opposite to the pillar side of the first cell. In this case, the gas passage is inflated with gas prior to the inflation of the first cell. Until the gas passage is inflated, the airbag pushes and opens a cover so as to start to deploy into a vehicle cabin. Therefore, the first cell is pulled by a portion that includes the inflated gas passage, whereby the first cell opens the pillar cover and is pulled out into the vehicle cabin before the first cell starts to be inflated or the cells are inflated a little. Because the first cell which is not or scarcely inflated is still small in volume, the first cell can be smoothly pulled out with little interference with the pillar cover. Then, the first cell coming out of the cover can be smoothly inflated with introduced gas without any restraint by the pillar cover.  
         [0012]     The gas passage preferably includes a first gas passage extending substantially vertically from an upper portion to a lower portion of the head protective airbag, and a second gas passage extending along the lower side of the head protective airbag and connecting the first gas passage to the first cell.  
         [0013]     According to an embodiment of the invention, after the first gas passage extending vertically is inflated to deploy downwardly, a second gas passage is inflated whereby the first cell is dragged out of the pillar cover. In this case, it is preferable that the at least one second cell is disposed along the first gas passage. According to this head protective airbag, when the first gas passage of the airbag is inflated to deploy downwardly, the second cell is pulled downwardly by the inflated first gas passage. Therefore, the second cell can be smoothly inflated.  
         [0014]     According to an embodiment of the present invention, the first cell may be formed substantially in a triangular profile of which one side extends along the pillar and the gas passage is connected to a portion including an opposing corner of the one side of the triangular profile. Because the triangular first cell starts to come out of the pillar cover at an apex (the aforementioned corner) of the triangular profile, the resistance applied to the first cell by the pillar cover is extremely small.  
         [0015]     It is an object of the present invention to provide a bottom filled side airbag that is designed to deploy a thinner, non-fully inflated airbag down into a fully extended position prior to a final filling of the airbag chambers. An airbag operating in this manner may reduce excessive, undesirable contact with an occupant during deployment when the occupant is near, or in contact with, the interior surface or structure of a vehicle. This airbag may reduce the time for the airbag to deploy into its operating position, provide a thinner volume during the initial stages of deployment, and reduce the total air bag volume. It is an object of the present invention to provide a side airbag module using this side airbag.  
         [0016]     According to an embodiment of the present invention, a side curtain airbag for protecting an occupant of a vehicle, is provided that includes at least one fill channel, wherein the fill channel is adapted to channel inflation gas from a top portion of the airbag to a bottom portion of the airbag, causing the bottom portion of the airbag to initially inflate, then subsequently and progressively fill airbag chambers from lower portions of the airbag upward to a top of the airbag, where the airbag is configured so that all the inflation gas passes through the fill channel.  
         [0017]     According to an embodiment of the present invention, a bottom fill airbag for the side of a vehicle is provided that includes at least one fill channel, wherein the fill channel is adapted to channel all inflation gas from an inflator directly to a bottom portion of the airbag, causing the bottom portion of the airbag to initially inflate, then subsequently and progressively fill airbag chambers from lower portions of the airbag upward to a top of the airbag.  
         [0018]     In an embodiment of the present invention, a side airbag module for protecting the occupant of a vehicle is provided that includes an inflator and an airbag that includes at least one fill channel, wherein the fill channel is adapted to channel all inflation gas to a bottom portion of the airbag, causing the bottom portion of the airbag to initially inflate, then subsequently and progressively fill airbag chambers from lower portions of the airbag upward to a top of the airbag.  
         [0019]     According to an embodiment of the present invention, a side curtain airbag for protecting an occupant of a vehicle is provided that includes an airbag with at least one inflation chamber and at least one fill channel for carrying inflation gas to at least one inflation chamber, wherein the ratio of the volume of the fill channel to the total inflatable volume of the airbag is less than 0.2.  
         [0020]     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only, and are not restrictive of the invention as claimed. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]     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.  
         [0022]      FIG. 1  is a front view, as seen from a vehicle cabin, showing a head protective airbag according an embodiment of the present invention.  
         [0023]      FIG. 2  is an illustration showing a deployment process of the head protective airbag.  
         [0024]      FIG. 3  is an illustration showing a deployment process of the head protective airbag.  
         [0025]      FIG. 4  is an illustration showing a deployment process of the head protective airbag.  
         [0026]      FIG. 5  is a front view, as seen from a vehicle cabin, showing a head protective airbag according another embodiment.  
         [0027]      FIG. 6  is a side view of a bottom fill side airbag according to an embodiment of the present invention.  
         [0028]      FIG. 7  is a side view of a bottom fill side airbag in a deployed state according to an embodiment of the present invention.  
         [0029]      FIG. 8  is a side view of a bottom fill side airbag with multiple fill channels according to an embodiment of the present invention.  
         [0030]      FIG. 9  is a side view of a bottom fill side airbag according to an embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0031]     Hereinafter, embodiments of the present invention will be described with reference to the attached drawings.  FIG. 1  is a front view, as seen from a vehicle cabin, showing a head protective airbag according an embodiment of the present invention and  FIGS. 2-4  are illustrations showing deployment processes of the head protective airbag. In the following description, the longitudinal direction is the longitudinal (back-and-forth) direction of a vehicle to which the head protective airbag is installed.  
         [0032]     A head protective airbag  1  of this embodiment is folded and disposed to extend from an A-pillar  31  to a B-pillar  33  through a roof side rail  32  of a vehicle  30 . The airbag  1  has substantially a trapezoidal profile in the deployment state so that it is inflated into a curtain shape to extend along a side surface of the vehicle cabin from the roof side rail  32  and the respective pillars  31 ,  33  to the vicinity of the upper edges of front and rear door panels  34 ,  35  so as to cover over the upper half of a side face of the vehicle cabin in the event of a lateral collision or roll-over of a vehicle.  
         [0033]     That is, the airbag  1  has a front side  1   a  to be extending along the A-pillar  31 , a lower side  1   b  to be extending along the upper edges of the door panels  34 ,  35 , a rear side  1   c  to be extending along the B-pillar  33 , and an upper side  1   d  to be extending along the roof side rail  32  wherein the lower side  1   b  is longer than the upper edge  1   d  so that the airbag  1  substantially has a trapezoidal profile.  
         [0034]     The airbag  1  comprises two sheets which are joined to each other by joints including a line-shaped joint  2  extending around their peripheries (with some parts thereof extending inward of the sheets), line-shaped joints  3 - 7  extending inside the peripheries, and circular joints  8 - 14  for reinforcing areas around ends of the line-shaped joints  3 - 7 . The airbag  1  is designed to be inflated by introduction of gas into spaces between the sheets. It should be noted that the line-shaped joints  2 - 7  and the circular joints  8 - 14  may be formed by any of various joining processes such as sewing, bonding, and welding.  
         [0035]     The airbag  1  has an L-shaped projection  15  extending from a middle portion in the longitudinal direction of the upper side Id thereof. Formed in the projection  15  is a gas inlet  16  for introducing gas into the airbag  1 . A gas generator (inflator)  17  is connected to the gas inlet  16  for inflating the airbag  1 . In an alternative embodiment, the projection  15  may be a separate piece from the airbag  1 .  
         [0036]     The line-shaped joint  2  comprises a front part  2   a  extending along the front side  1   a , a lower part  2   b  extending along the lower side  1   b , a rear part  2   c  extending along the rear side  1   c , and an upper part  2   d  extending along the upper side  1   d  of the airbag  1 .  
         [0037]     The line-shaped joint  3  extends to communicate with a circular joint  8  which is disposed near a corner formed by the front side  1   a  and the upper side  1   d  of the airbag  1 . The circular joint  8  is positioned to border on or quite close to the line-shaped joint  2  at the corner.  
         [0038]     The line-shaped joint  3  is formed in a U-like shape comprising a front part  3   a  extending diagonally from the circular joint  8  to the lower back of the airbag  1 , a middle part  3   b  as a continuation of the front part  3   a  and extending substantially in the longitudinal direction at about the middle in the vertical direction of the airbag  1 , and a rear part  3   c  extending from the middle part  3   b  toward a middle portion in the longitudinal direction of the upper side  1   d  of the airbag and connected to a circular joint  9 .  
         [0039]     The middle part  3   b  of the line-shaped joint  3  is spaced apart from the line-shaped joint  2  extending along the lower side  1   c  of the airbag, thereby forming a second gas passage  22  between the line-shaped joint  2  and the middle part  3   b  of the line-shaped joint  3 . The second gas passage  22  extends in the longitudinal direction along the lower part  2   b  of the line-shaped joint  2  in a lower portion of the airbag  1 .  
         [0040]     A first cell  18  formed substantially in a triangular profile is defined by the front part  3   a  of the line-shaped joint  3  extending diagonally to the lower back, a front-side portion of the lower part  2   b  of the line-shaped joint  2  extending in the longitudinal direction, and the front part  2   a  of the line-shaped joint  2  extending along the A-pillar  31 . The triangular first cell  18  communicates with the second gas passage  22  at an opposing corner of the front part  2   a  of the line-shaped joint of the first cell  18 , that is, at a corner between the rear side and the lower side of the first cell  18 .  
         [0041]     Inside the first cell  18 , a line-shaped joint  4  formed substantially in a triangular profile which is similar to and smaller than the figure of the first cell  18  is formed. An inside area  19  defined by the line-shaped joint  4  is a non-inflatable portion into which no gas is introduced. The non-inflatable portion acts to prevent the thickness of the airbag when inflated from being too large. The line-shaped joint  4  extends in a loop starting from a circular joint  10  and returning to the circular joint  10 .  
         [0042]     Formed between the rear part  3   c  of the line-shaped joint  3  and a line-shaped joint  6  is a first gas passage  21 . The upper portion of the first gas passage  21  faces the aforementioned gas inlet  16  and the lower portion of the first gas passage  21  communicates with the second gas passage  22 . The first gas passage  21  extends in the vertical direction at a middle portion in the longitudinal direction of the airbag  1 .  
         [0043]     A second cell  20   a  is defined along the front-side of the first gas passage  21 . The second cell  20   a  is formed in a U-like shape between the line-shaped joint  3  and the line-shaped joint  5 . In this embodiment, two circular joints  11  and  12  are formed at substantially the same level (height) with of the circular joint  9  in front of the circular joint  9 . The line-shaped joint  5  is formed to extend in a U-like shape between the circular joints  11  and  12 .  
         [0044]     A line-shaped joint  6  is formed substantially in a C-like shape as a continuation of the lower part  2   b  of the line-shaped joint  2 , extending upwardly at a middle portion in the longitudinal direction of the airbag  1 , and being curved rearwardly toward a circular joint  13 .  
         [0045]     The lower part  2   b  of the line-shaped joint  2  extends substantially into a Ω-like shape between a middle portion and a rear portion of the airbag  1  and returns to the vicinity of the lower side  1   b  of the airbag  1 . An area  24  defined and surrounded by the lower part  2   b  of the line-shaped joint  2  in the Ω-like shape is a non-inflatable portion into which no gas is introduced. A cell  23   a  is formed between this area  24  and the first gas passage  21 , a cell  23   b  is formed between this area  24  and a line-shaped joint  7 , and a cell  23   c  is formed between the line-shaped joint  7  and the rear part  2   c  of the line-shaped joint  2 .  
         [0046]     The line-shaped joint  7  branches from a portion near the lower end of the rear part  2   c  of the line-shaped joint  2  and extends upwardly to reach a circular joint  14 .  
         [0047]     The circular joints  11 ,  12 ,  9 ,  13 ,  14  may be positioned substantially at the same level (height), thereby forming a narrow gas passage, extending along the upper side  1   d  of the airbag  1 , between these circular joints  11 ,  12 ,  9 ,  13 ,  14  and the upper part  2   d  of the line-shaped joint  2 .  
         [0048]     The airbag  1  may be folded by pulling the lower edge thereof up and is disposed along about the roof side rail  32 , the A-pillar  31 , and the C-pillar  33 . In a storage position, the airbag  1  may be covered by a suitable cover such as a pillar trim and a roof trim (not shown).  
         [0049]     The airbag  1  having the aforementioned structure acts as follows. When the vehicle is involved in a lateral collision or roll-over, the inflator  17  is activated to supply gas into the airbag  1 . The gas from the inflator  17  flows through the gas inlet  16  mainly to the first gas passage  21  so as to inflate the middle portion in the longitudinal direction of the airbag  1  downwardly as shown in  FIG. 3 . Then, the airbag  1  pushes and open a roof trim  36 B above a B-pillar  37  and thus starts to deploy into the vehicle cabin.  
         [0050]     After the middle portion of the airbag  1  further deploys along the B-pillar from the state shown in  FIG. 3 , gas flows into the second gas passage  22  so that the lower edge portion of the airbag  1  is also inflated. At the time when the second gas passage  22  starts to be inflated, a portion about the first cell  18  of the airbag  1  is pulled or dragged by already-inflated portions of the airbag  1 , i.e. the second gas passage  22  and the area around the second gas passage  22 , so as to tear a trim  36 A of the A-pillar and come out of the trim  36 . Gas from the second gas passage  22  is introduced into the first cell  18  thus pulled out, thereby inflating the first cell  18 .  
         [0051]     As described above, according to one embodiment of the present invention, the inflation of the first cell  18  is carried out after the first cell  18  is dragged out of the trim  36 . When the first cell  18  comes out of the A-pillar trim  36 A, the first cell  18  is not or scarcely inflated so that the first cell  18  is still small in volume. Accordingly, the frictional resistance applied to the first cell  18  by the A-pillar trim  36 A is extremely small so that the first cell  18  can be extremely smoothly dragged out of the trim  36 A. In addition, the trim  36 A is required to create a smaller slit through which the airbag  1  is pulled out so that the trim  36 A has a simple structure.  
         [0052]     In this embodiment, the first cell  18  has a triangular profile of which one side extends along the A-pillar  31  and communicates with the second gas passage  22  at an opposing corner of the side along the A-pillar  31 . When the second gas passage  22  is inflated, the first cell  18  starts to come out of the trim  36 A at the corner side thereof. Therefore, the resistance applied to the first cell  18  by the trim  36 A when the first cell  18  is dragged out of the trim  36 A is extremely small, thereby allowing smooth deployment of the first cell  18 .  
         [0053]     When gas flows into the first gas passage  21  so that the middle portion of the airbag  1  is inflated downwardly as shown in  FIG. 3 , the first cell  20   a  and the cell  23   a  adjacent to the first gas passage  21  are also pulled by the inflated first gas passage  21  and is thus dragged out of the trim  36 B. Because these cells  20   a ,  23   a  are inflated mainly outside the trim  36 B, the movement of the airbag  1  pushing and opening the trim  36 B to deploy out of the trim  36 B is also smooth.  
         [0054]     In this embodiment, because the cells  23   b  and  23   c  are also pulled by the first gas passage  21  which is already inflated or being inflated, the cells  23   b  and  23   c  are dragged out of the trims  36 B,  36 C into the vehicle cabin before the cells start to be inflated or the cells are inflated a little. The movement of these cells is also smooth.  
         [0055]     Though the triangular first cell  18  is provided only in a front portion of the airbag  1  along the A-pillar  31  in the aforementioned embodiment, a triangular first cell may also be provided in a rear portion of the airbag along the C-pillar  33 .  
         [0056]      FIG. 5  shows an airbag  1  A according to another embodiment having such a structure. The airbag  1  A has triangular cells  18 A,  23 C formed in a front portion and a rear portion thereof. At the centers of the cells  18 A,  23 C, triangular non-inflatable areas  19 ′,  24 ′ are formed by line-shaped joints  4 ′,  4 ″, respectively. The cells  18 A,  23 C are defined by line-shaped joints  3 ′,  3 ″, respectively. The line-shaped joints  3 ′,  3 ″ are connected to circular joints  8 ′,  14 ′ formed at front and rear corners of the upper side of the airbag, respectively. A first gas passage  21  A is formed between the liner-shaped joints  3 ′and  3 ″. Formed between the line-shaped joints  3 ′,  3 ″ and a lower part of a line-shaped joint  2 ′ extending along the periphery of the airbag are second and third gas passages  22 A,  22 B which communicate with the first gas passage  21 A and extend in the longitudinal direction.  
         [0057]     The line-shaped joints  3 ′,  3 ″ are formed in U-like shape. Formed inside the U-like line-shaped joints  3 ′,  3 ″ are U-like line-shaped joints  5 ′,  5 ″, respectively. Second cells  20 A,  23 A are formed between the line-shaped joints  3 ′,  3 ″ and the line-shaped joints  5 ′,  5 ″, respectively.  
         [0058]     Further, formed inside the line-shaped joints  5 ′,  5 ″ are cells  20 B,  23 B. The airbag  1 A is connected at a front end and a rear end thereof to the A-pillar and the C-pillar via projections  26 .  
         [0059]     Also in this embodiment, gas from an inflator  17 A introduced through a gas inlet  16 A positioned substantially at a middle portion in the longitudinal direction of the airbag and flows into the first gas passage  21  A to start the inflation of the airbag  1 A as shown in  FIG. 3  and to quickly draw out the first cells  18 A,  23 C from trims of the A-pillar and the B-pillar. Because the cells  18 A,  23 C are not or scarcely inflated when pulled out, the cells  18 A,  23 C can be smoothly pulled out through small slits of the trims.  
         [0060]     The above embodiments are both illustrative examples of the present invention and the present invention is not limited to the above embodiments. For example, the profile and location of the second cell may be changed. Even the profile of the first cell is not limited to triangle and may be substantially trapezoid, semi-circle, or square.  
         [0061]     Though the line-shaped joint having a shape similar to and smaller than the first cell is provided inside the first cell and the area inside the line-shaped joint is non-inflatable portion in the above embodiments, the shape of the line-shaped joint is not limited to the shape similar to the first cell. Moreover, the non-inflatable portion may be omitted.  
         [0062]     Though the circular joints are provided at ends of the line-shaped joints for reinforcing areas around ends of the line-shaped joints defining the first and second cells and the first and second gas passages, the circular joints may be omitted by connecting an end of a line-shaped joint to a midway of another line-shaped joint and by connecting ends of line-shaped joints.  
         [0063]     Though the first gas passage is disposed substantially at the middle in the longitudinal direction of the airbag in the above embodiments, the location of the first gas passage is not limited thereto. Further, two first gas passages may be provided to be disposed at difference locations in the longitudinal direction of the airbag. In this case, it is preferable that the airbag is provided along the upper side of the airbag with a gas distributing means such as a duct having gas ports which are in communication with upper parts of the respective first gas passages.  
         [0064]     Though the gas inlet is disposed substantially at the middle in the longitudinal direction of the upper side of the airbag in the above embodiments, the location of the gas inlet is not limited thereto. The inflator to be connected to the gas inlet may be located at any place such as the roof side rail or the C-pillar of the vehicle. When the inflator is located in the C-pillar, a duct for introduction of gas may be connected to the inflator in order to introduce gas from the inflator into the first gas passage.  
         [0065]     Though the head protective airbag is fabricated by joining two sheets together in the above embodiments, the fabrication of the airbag is not limited thereto. For example, the airbag may be obtained by using a base fabric which is woven originally into an envelope shape by a so-called “hollow weaving” or “jacquard weaving” method. In this case, the first and second cells and the first and second gas passages are formed inside the airbag by woven joints inside and along the periphery of the airbag, instead of joining the opposite surfaces of the airbag by the line-shaped joints to divide the inside of the airbag.  
         [0066]     As described above, according to the present invention, a head protective airbag can be smoothly dragged out of interior members such as trims when a gas generator of a head protective airbag device is actuated.  
         [0067]     FIGS.  6  shows a side views of a bottom filled side airbag  100  according to an embodiment of the present invention. In the example shown in  FIG. 6 , the airbag  100  has asymmetrical chambers  105 ,  110 .  
         [0068]      FIG. 7  shows a side view of a bottom filled side airbag  100  according to an embodiment of the present invention in a deployed state. The bottom filled side airbag includes one or more fill channels  120  that direct inflation gas from an inflator  190  to a bottom portion of the airbag. Inflation gas is then directed through one or more passages into one or more fill chambers. In the example shown in  FIG. 7 , a passage  130  directs inflation gas from fill channel  120  into a forward fill chamber  150  and a passage  140  directs inflation gas into a rear chamber  160 . Fill chambers may include circular joints  162 ,  164 ,  166 ,  168 . Alternatively, fill chambers may include non-inflatable regions instead of, or in addition to, circular joints. The bottom fill side airbag may include non-inflatable portions  170  outside of the fill chambers.  
         [0069]     In the example shown in  FIG. 7 , the bottom fill side airbag is stored in vehicle headliner  180  before deployment. In the example shown in  FIG. 7 , the airbag deploys along an interior surface of a vehicle so that middle pillar  185 , or “B” pillar, is aligned at the center of the airbag.  
         [0070]      FIG. 8  shows a side view of a bottom fill side airbag according to an embodiment of the present invention. In the example shown in  FIG. 8 , two fill channels  200 ,  210  are used to provide inflation gas from an inflator  320  to a bottom portion of an airbag.  
         [0071]     Alternatively, two inflators may be provided so that each fill channel has a dedicated inflator. Inflation gas is then directed through one or more fill passages into one or more fill chambers. In the example shown in  FIG. 8 , a passage  220  supplies inflation gas from a fill channel to a forward fill chamber  240  while a passage  230  provides inflation gas to a rear chamber  250 . Fill chambers may include circular joints  260 ,  270 ,  280 ,  290 . Alternatively, fill chambers may include non-inflatable regions instead of, or in addition to, circular joints. The bottom fill side airbag may include non-inflatable portions  330  outside of the fill chambers.  
         [0072]     The volume of the fill channel is designed so that it is a fraction of the total inflatable volume of the airbag. For example, the ratio of the volume of the fill channel to the total inflatable volume of the airbag may be less than 0.2.  
         [0073]      FIG. 9  shows a side view of a bottom fill side airbag according to an embodiment of the present invention. In the example shown in  FIG. 9 , the fill channel  120  has been designed so it is separated from a top portion of the airbag chambers, creating a separation  340 . This allows the fill channel  120  to be designed in different configurations and different volumes. For example, the fill channel  120  may be configured to be tall, short, narrow, and/or wide. In a further example, the fill channel may be designed so that the ratio of the volume of the fill channel to the total inflatable volume of the airbag may be less than 0.2. Inflation gas passes through the fill channel  120  so that a portion of the gas may pass through separation  340  and into chambers  350 ,  360 , while another portion of the gas passes to the bottom of the airbag, through passages  390  and into chamber  370 ,  380 . The configuration of the chambers in  FIG. 9  is exemplary and may take different form. For example, chambers  350  and  370  do not have to have complete seams or seals between one another and instead be linked by a common passage or passages. Chambers may also have smaller chambers within each chamber or be configured with different sizes and geometries, as is known in the art.  
         [0074]     The bottom fill side airbag of the present invention may have one or a plurality of fill chambers. The airbag may include non-inflating portions in addition to fill chambers.  
         [0075]     Channels that direct inflation gas to the bottom of a side airbag may be used to fill one or a plurality of fill chambers. The bottom fill side airbag may be folded and/or rolled to prepare the airbag for containment in a vehicle.  
         [0076]     The bottom fill side airbag of the present invention may use one or more inflators per fill channel or one inflator for a plurality of fill channels. Airbag fill channels may be positioned at or near the middle of the length of the airbag or at an end of the airbag.  
         [0077]     An inflator may be a non-reactive inflator, reactive inflator, hybrid inflator, or other inflator device known in the art.  
         [0078]     In the example shown in  FIG. 8 , the bottom fill side airbag is stored in vehicle headliner  310  before deployment. In the example shown in  FIG. 8 , the airbag deploys along an interior surface of a vehicle so that middle pillar  300 , or “B” pillar, is aligned at the center of the airbag.  
         [0079]     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 a set forth in the following claims.