Abstract:
An air bag cushion for vehicles has a connection part which is formed in front portions of the left and right chambers by sewing the inner surfaces of the left and right chambers along sewing lines in a shape of closed curve to form a vertical valley which separates the left and right chambers from each other. A through hole is formed in the connection part to permit gas to flow between the left and right chambers. The cushion includes a tether which passes through the connection part and connects the left and right chambers to each other in a lateral direction of the cushion. The air bag cushion is simple in structure and is superior in uniform expanding performance of the left and right chambers.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims priority of Korean Patent Application Number 10-2009-0070925 filed on Jul. 31, 2009, the entire contents of which application is incorporated herein for all purposes by this reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to an air bag cushion for vehicles intended to protect a passenger and, more particularly, to an air bag cushion for a front passenger seat. 
     2. Description of Related Art 
     Recently, with the increasing demands on the safety and protection for passengers, the ratio of vehicles equipped with front passenger air bags are on the increase. 
     A conventional front passenger air bag may be not helpful, rather dangerous for a child sitting in a front passenger seat. That is because children are usually seated on the front passenger seat using a child restraint system (CRS) and positioned on a side of front edge of the front passenger seat. In this case, the sudden expansive force of an air bag cushion in an initial expansion stage may strike a child&#39;s face and cause a neck injury of the child. 
       FIG. 1A  is a view illustrating the expansion of an air bag cushion for a front passenger seat which was developed recently. The air bag cushion  1  is constructed so that a vertical valley  4  is formed between left and right chambers  2  and  3  (hereinafter, referred to as a ‘vertical two-chamber structure’). The left chamber  2  expands towards the left side of the upper part of the body of a passenger (not shown), the right chamber  3  expands towards the right side of the upper part of the passenger&#39;s body, and the upper portion of the valley  4  comes into contact with the passenger&#39;s face. Reference numeral  5  denotes an exterior vent hole for discharging gas from the air bag cushion. The air bag cushion  1  is designed such that a child&#39;s face comes to rest on the valley  4 , mainly, on a portion around the lower end of the valley  4  in the event of a vehicle collision, thus preventing the child from being injured, unlike a conventional air bag cushion. 
     However, the air bag cushion having the vertical two-chamber structure shown in  FIG. 1A  is complicated in structure. In the process of manufacturing the air bag cushion, operations of sewing two sheets  6  and  7  along their edges as shown in  FIG. 1B  are frequently required. In this case, remnants  9  may be undesirably left behind outside of the sewing lines  8 . In order to make the appearance good, the sheets  6  and  7  sewn along the edges as shown in  FIG. 1B  must be turned inside out so that the remnants  9  are not exposed to the outside of the finished air bag cushion. In the case of the vertical two-chamber structure requiring the sewing of several sheets, the sequence of sewing is complicated, so that the structure and manufacture of the air bag cushion are complicated. 
     The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art. 
     BRIEF SUMMARY OF THE INVENTION 
     Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and the present invention provides for an air bag cushion for vehicles having a vertical two-chamber structure, which is simple in structure. 
     The present invention also provides for an air bag cushion for vehicles having a vertical two-chamber structure, which allows symmetric and uniform expansion of two chambers thereof. 
     The present invention further provides for an air bag cushion for vehicles having a vertical two-chamber structure, in which a variety of shapes of the valley between the two chambers can be achieved easily. 
     In order to accomplish such, the present invention provides an air bag cushion, including a left chamber configured to be expanded towards a left side of an upper part of a body of a passenger, a right chamber configured to be expanded towards a right side of the upper part of the body of the passenger, and at least one connection part formed in front portions of the left and right chambers by sewing facing inner surfaces of the left and right chambers along sewing lines in a shape of closed curve to form a vertical valley which separates the left and right chambers from each other. A through hole is formed in the connection part to permit gas to flow between the left and right chambers. 
     The left chamber may include a left outer sheet and a left inner sheet sewn along an edge thereof to the left outer sheet. The right chamber may include a right inner sheet sewn to the left inner sheet at the connection part and a rear end thereof, and a right outer sheet sewn along an edge thereof to the right inner sheet. 
     The left chamber may be provided by sewing the left and right inner sheets to each other at the connection part, sewing the left outer sheet and the left inner sheet to each other along edges thereof with the right inner sheet placed between the left outer sheet and the left inner sheet, and turning the left outer sheet inside out. 
     The right chamber may be provided by sewing the left and right inner sheets to each other at the connection part, sewing the right outer sheet and the right inner sheet to each other along edges thereof with the left inner sheet placed between the right outer sheet and the right inner sheet, and turning the right outer sheet inside out. 
     Further, rear ends of the left and right inner sheets may be sewn vertically and horizontally so that a partition part is provided at rear ends of the left and right chambers to partition the left and right chambers from each other. 
     Further, a gap at which the left and right inner sheets are not sewn may be provided between the connection part and the partition part. 
     Further, a gas injection part may be provided in the rear ends of the left and right chambers in such a way as to communicate with the chambers, with gas being injected from the inflator to the gas injection part. 
     The air bag cushion may further include at least one joining part placed in front of the connection part and provided by sewing the left and right inner sheets to each other along sewing lines in a shape of a closed curve. 
     The joining part may be formed to become ripped more easily than the connection part. 
     The air bag cushion may further include a tether which passes through the connection part and connects the left and right chambers to each other in a lateral direction of the air bag cushion. 
     Further, one end of the tether may be connected to the left outer sheet and the other end may be connected to the right outer sheet. 
     The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description of the Invention, which together serve to explain certain principles of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a view illustrating a conventional air bag cushion. 
         FIG. 1B  is a view illustrating the process of manufacturing the conventional air bag cushion. 
         FIG. 2  is a schematic view illustrating an air bag cushion according to the present invention. 
         FIG. 3  is a schematic exploded view illustrating the air bag cushion of  FIG. 2 . 
         FIGS. 4A to 4F  are views illustrating the process of manufacturing the air bag cushion of  FIG. 2  in stages. 
         FIGS. 5A and 5B  are views illustrating the process of finishing the rear end of the air bag cushion of  FIG. 2 . 
         FIGS. 6A and 6B  are schematic views illustrating other air bag cushions according to the present invention. 
         FIGS. 7A to 7F  are schematic views illustrating other air bag cushions according to the present invention. 
         FIGS. 8A to 8C  are a plan view, a front view, and a right side view illustrating the air bag cushion manufactured according to the present invention, respectively. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims. 
     As shown in  FIG. 2 , the air bag cushion  10  is constructed so that a vertical valley  18   a  is formed on the front portions of left and right chambers  11  and  12  to separate the chambers  11  and  12  from each other. The left and right chambers  11  and  12  are sewn to each other at a connection part  15  and a partition part  16 . A gap  18   b  at which both chambers  11  and  12  are not sewn is provided between the connection part  15  and the partition part  16 . 
     A gas injection part  19  is provided on the rear ends of the left and right chambers  11  and  12 . A housing  80  for accommodating the air bag cushion  10  and an inflator  70  supported by the housing  80  are installed around the gas injection part  19 . The inflator  70  is mounted outside the air bag cushion  10  and a gas discharge port of the inflator  70  is partially inserted into the cushion  10 . Of course, the inflator  70  may be installed inside the air bag cushion  10 . 
     The gas, injected from the inflator  70  to the gas injection part  19 , is supplied to the left and right chambers via the partition part  16  which partitions the left and right chambers at the rear side of the air bag cushion  10 . Reference numeral  17  denotes sewing lines which define the gas injection part  19 . The sewing lines  17  of the gas injection part  19  will be described in detail with reference to  FIG. 3 . In this context, it should be understood that the well known retainer ring placed in the air bag cushion  10  for retaining the inflator  70  to the cushion  10  is not shown in  FIG. 2 . 
     At least one through hole  15   b  (see  FIG. 3 ) is formed in each connection part  15  to permit air to flow between the left and right chambers  11  and  12 . The gas may be non-uniformly supplied from the gas injection part  19  to the left and right chambers  11  and  12 , and the expansion speed of the chambers  11  and  12  may be different. The through hole  15   b  allows the gas to be uniformly dispersed to both chambers  11  and  12 , thus causing the chambers  11  and  12  to uniformly and symmetrically expand. 
     Still referring to  FIG. 2 , a tether  60  is provided on the front portions of the left and right chambers  11  and  12  and passes through the connection part  15  to connect the left and right chambers  11  and  12  to each other in a direction from the left side of the cushion  10  to the right side thereof. 
     The tether  60  functions to hold the shape of the air bag cushion  10  during and after the expansion of the cushion  10  and make the two chambers  11  and  12  expand symmetrically. For example, if the expanding speed of the left chamber  11  is higher than that of the right chamber  12  as a result of non-uniform supply to both chambers  11  and  12 , the tether  60  delays the expansion of the left chamber  11  and make pressurized gas be distributed from the left chamber  11  through the through hole  15   b  to the right chamber  12 . 
     The construction and components of the air bag cushion  10  will be described with reference to  FIGS. 2 and 3 . 
     The left chamber  11  is manufactured by sewing a left outer sheet  20  and a left inner sheet  30  along edge sewing lines  13 . The right chamber  12  is manufactured by sewing a right outer sheet  50  and a right inner sheet  40  along edge sewing lines  14 . The left inner sheet  30  and the right inner sheet  40  are sewn at their rear ends  32  and  42  with the connection part  15 . 
     At least one through hole  15   b  is formed in an area forming the connection part  15  of each of the left and right inner sheets  30  and  40 . When the through hole  15   b  is too small, it is insufficient to remove the non-uniform expansive pressure of the left and right chambers  11  and  12 . In contrast, when the through hole  15   b  is too large, the external impact bearing force of the cushion  10  may be reduced. Thus, it is preferable that one or several through holes  15   b  having a proper size be formed. The left and right inner sheets  30  and  40  may be sewn around the through holes  15   b , in addition to the sewing lines  15   a  of the connection part  15 . 
     Sewing lines provided at the rear ends  32  and  42  of the left and right inner sheets  30  and  40  define the partition part  16  which is provided on the rear ends of the left and right chambers  11  and  12  to partition them from each other. The gas, which is injected from the inflator  70  to the gas injection part  19 , is divided at the partition part  16  and supplied to the left and right chambers  11  and  12 . The sewing lines of the partition part  16  are formed horizontally as well as vertically. A bolt inserted from the known retainer ring is fastened through a mounting hole  72  so that the inflator  70  is locked to the air bag cushion  10 . 
     Meanwhile, as shown in  FIG. 3 , the length D of the rear ends  22  and  52  of the left and right outer sheets  20  and  50  is longer than the length d of the rear ends  32  and  42  of the left and right inner sheets  30  and  40 . The reason for this is because openings formed in the rear portions of the chambers  10  and  20  are closed (see  FIGS. 5A and 5B ) using the rear ends  32  and  42  and the gas injection part  19  is formed in the openings. A recess  19   a  is provided in the rear ends  32  and  42  of the left and right inner sheets  30  and  40  to provide the gas injection part  19 , and inflator holes  71  and mounting holes  72  are formed in the rear ends  22  and  52  of the left and right outer sheets  20  and  50 . 
     The method of manufacturing the air bag cushion  10  will be described with reference to the above-mentioned drawings and  FIGS. 4A to 4F .  FIGS. 4A to 4F  are sectional views taken along line A-A of  FIG. 3  and illustrating the process of sewing the sheets  20 ,  30 ,  40  and  50  in sequence. 
     As shown in  FIGS. 4A and 4B , in the state where the left inner sheet  30  and the right inner sheet  40  face each other, the front portions of the sheets  30  and  40  are sewn along the sewing lines  15   a  in the shape of a closed curve, thus forming the connection part  15 . Further, the rear ends of the left and right inner sheets  30  and  40  are sewn, thus forming the partition part  16  (see  FIG. 3 ). 
     As shown in  FIG. 4C , in the state where the left outer sheet  20  is placed to a side of the right inner sheet  40 , the left outer sheet  20  and the left inner sheet  30  are sewn along the edge sewing lines  13 . Next, a pocket formed by the left outer sheet  20  is turned inside out. Thereby, the left chamber  11  having the edge sewing lines  13  therein is obtained as shown in  FIG. 4D . 
     In the above-mentioned manner, as shown in  FIG. 4E , in the state where the right outer sheet  50  is placed to a side of the left outer sheet  20 , the right outer sheet  50  and the right inner sheet  40  are sewn along the edge sewing lines  14 . Next, the right outer sheet  50  is turned inside out. Thereby, the right chamber  12  having the edge sewing lines  14  therein is obtained as shown in  FIG. 4F . 
     Such a sewing sequence enables the easy sewing of the sheets  20 ,  30 ,  40  and  50 , in spite of the existence of the connection part  15 . The sequence of sewing the sheets  20 ,  30 ,  40  and  50  may be changed. For example, the right chamber  12  may be firstly formed by sewing the right inner sheet  40  and the right outer sheet  50  along the sewing lines  14  after placing the left inner sheet  30  between the right inner sheet  40  and the right outer sheet  50 . 
       FIGS. 5A and 5B  are schematic views illustrating the process of forming the gas injection part  19  using the rear ends  22  and  52  of the left and right outer sheets  20  and  50 . It should be understood that the shape of the air bag cushion shown in the drawings may be different from an actual shape since the drawings are schematically shown. 
     Referring to  FIGS. 2 ,  3 ,  5 A and  5 B, after the rear ends  22  and  52  of the left and right outer sheets  20  and  50  are folded from the state of  FIG. 4F  such that the inflator holes  71  overlap each other, the rear ends  22  and  52  are sewn together with the front ends  21  and  51  of the sheets  20  and  50  along the sewing lines  17 , so that the gas injection part  19  is formed at the rear ends of the left and right chambers  11  and  12 . The gas discharge port of the inflator  70  is inserted through the inflator holes  71  into the gas injection part  19 , and the inflator  70  is coupled to the retainer ring by fastening members which are fitted into the mounting holes  72 . 
     Referring to  FIGS. 6A and 6B , the connection of the left and right chambers  11  and  12  which is made through the connection part  15  enables the shape of the valley  18   a  and the chambers  11  and  12  to be variously changed as necessary. For example, the valley  18   a  may be formed from the upper portions of the left and right chambers  11  and  12  to the lower portions thereof as shown in  FIG. 6A , or may be formed such that there is a deep valley  18   a  in the lower portions of the left and right chambers  11  and  12  as shown in  FIG. 6B . All of the above-mentioned shapes of the air bag cushion are useful when it comes to protecting a passenger. 
     Referring to  FIGS. 7A ,  7 C and  7 D, the shape and number of connection parts  101  of the air bag cushions  100 ,  120  and  130  according to various embodiments of the present invention and the shape and number of the through holes  102  in an area of the connection part  101  may be changed. 
     Further, referring to  FIGS. 7B ,  7 E and  7 F, the air bag cushions  110 ,  140  and  150  according to various embodiments of the present invention may further include a joining part  103  which is placed in front of an associated connection part  101  and made by sewing the left and right inner sheets  30  and  40  together along sewing lines in the shape of a closed curve. The joining part  103  may be sewn using thread which is thinner than that of the connection part  101  or may be sewn more thinly than the connection part  101 . The joining part  103  is provided in front of the connection part  101  and ripped by collision with a passenger, thus absorbing impact and protecting the passenger. 
       FIGS. 8A to 8C  are drawings illustrating a cushion sample manufactured according to various embodiments of the present invention and seen at several angles. The sample is manufactured to check the manufacturability and convenience of the cushion according to the various embodiments. The rear end corresponding to the gas injection part is not assembled and is omitted from the drawings. 
     Meanwhile, according to other embodiments, the rear end and the front end of the cushion may be manufactured using separate sheets and then be sewn to provide a space for the gas injection part. Reference numeral  90  of  FIG. 8C  denotes an exterior vent hole which functions to reduce the internal pressure of the air bag cushion under given conditions. 
     As described above, the present invention provides an air bag cushion having a vertical two-chamber structure, which is simple in structure. 
     Further, the present invention provides an air bag cushion, which allows left and right chambers to uniformly expand. 
     Furthermore, the present invention provides an air bag cushion having a vertical two-chamber structure, which allows a valley to assume a variety of shapes which can easily be realized. 
     For convenience in explanation and accurate definition in the appended claims, the terms “upper” or “lower”, “front” or “rear”, “inside” or “outside”, and etc. are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures. 
     The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.