Abstract:
A curtain air bag device protects passengers within a car by preventing a front pillar trim from being detached from a front pillar panel upon the deployment of a curtain air bag. The front pillar trim is attached to a flexible curtain air bag back plate in which a curtain air bag is embedded. A space is provided through which the curtain air bag deploys. The front pillar trim is attached to the front pillar by a simple fixing means, such as a screw.

Description:
FIELD OF THE INVENTION 
   Generally, the present invention relates to a curtain air bag device. More particularly, the curtain air bag device includes a front pillar trim attached to a flexible back plate of the curtain air bag such that the front pillar trim is prevented from detachment from the front pillar during deployment of the air bag. 
   BACKGROUND OF THE INVENTION 
   Typically, an air bag is a safety device used in a car. The air bag fills with nitrogen gas obtained from burning innoxious solid chemicals following the operation of an impact sensor. The gas makes the air bag swell in a range of 0.02 to 0.05 seconds. The inflated air bag then prevents a secondary impact between the body of a passenger and the car structure. Air bags have increased the safety for passengers during automobile accidents. 
   During a side impact, the death rate of passengers is high. U.S. car accident statistics show that the number of deaths per year for side impacts amounts to roughly 30% of the total deaths from automobile accident. Recently, there has been a trend toward positioning a curtain air bag on a side roof line of automobiles. However, the typical curtain air bag has a structural drawback in that the pillar trim prevents the curtain air bag from completely covering the windows of the driver and passenger seats, thereby failing to protect the passengers of the car. Furthermore, the front pillar trim generally becomes detached from the front pillar causing injury to the occupants of the vehicle. 
   U.S. Pat. No. 6,402,188 B1, European Patent Publication No. EP 0 873 916 A1, and German Patent Publication No. DE 198 38 069 A1 have addressed some of the above drawbacks. As disclosed therein, the front pillar trim is configured with a notch to ensure a space through which the curtain air bag may deploy. Additional, a hook is inserted and supported to a front pillar panel for the purpose of preventing the front pillar trim from deviating from the front pillar panel. However, when the notch is formed on the front pillar trim, an additional skin material is required because the notch portion is substantially thinner, which renders the production cost undesirably raised. Further, the addition of the hook needs a strap or a specific clip for securing the front pillar trim, which renders the configuration rather complicated and also reduces assembly efficiency. 
   SUMMARY OF THE INVENTION 
   The present invention provides a curtain air bag device for providing safety for passengers in an automobile by preventing a front pillar trim from being deviated from a front pillar panel upon the deployment of a curtain air bag. 
   The present invention also provides a curtain air bag device which can attach a front pillar trim to a flexible curtain air bag back plate, in which a curtain air bag is embedded, using a simple fixing means such as a screw, while providing space enough to deploy the curtain air bag. 
   According to an embodiment of the invention there is provided a curtain air bag device comprising a curtain air bag back plate that includes a first body into which a curtain air bag is provided. The first body is adapted to be cut at one end in a direction in accordance with the deployment of the curtain air bag. Also included is one or more flexible first coupling end portions each extending from the edge of the one side of the first body and having a first through hole, a cut part, and a first coupling hole. A front pillar trim has a plurality of detachable mounting support parts formed on one side. Coupling pins are secured on one end thereof and correspond to the detachable mounting support parts and are detachably coupled to a front pillar panel on the other end by passing through the cut part and the first coupling hole. Also included is a coupling support part protruded on one side adjacent to a second through hole formed on each of the both ends thereof in such a manner as to correspond to the second through hole. A plurality of mounting support members each including a hollow type of second body having a screw coupling hole formed on one surface and opened on the other surface. A coupling end portion having an end extended from the edge of one side of the second body having a coupling hole formed thereon. A plurality of fixing parts each including a first coupling bolt passed through the coupling hole corresponding thereto for coupling to the coupling support part, and a second coupling bolt passed sequentially through the second through hole, the screw coupling hole, and the first through hole corresponding thereto in such a manner as to be inserted into the corresponding portion of the front pillar panel. 
   It is preferable that the first body of the curtain air bag back plate has a section in the shape of a trapezoid such that the length of one surface on which the cut part is formed is substantially shorter than that of the opposite surface. 
   It is preferable that the first through hole is provided with a metal reinforcing member for enhancing the rigidity of the first through hole. The reinforcing member includes a hollow type of body inserted into the inside of the first through hole and a locking end portion that is placed on the surface of the first coupling end portion. The outer peripheral surface of one end of the hollow type of body has an outer diameter larger than the inner diameter of the first through hole. 
   It is preferable that the coupling end portion of each of the mounting support members is coupled to each of the coupling support parts by means of each of the first coupling bolts. The second body of each of the mounting support members is disposed in such a manner that the center thereof is on the same line as the center of each of the second through holes. 
   It is also preferable that the curtain air bag device further comprises a stopper adapted to be inserted from the opposite direction of the front pillar trim on which the mounting supporting members are placed, such that, the second through hole is opened and closed. The stopper having a plurality of locking ends formed on one side thereof in such a manner as to be passed through the second through hole and locked to the one side of the front pillar trim. 
   Alternatively, a curtain air bag device of the present invention comprises a front pillar trim defining at least one hole therethrough and including at least one detachable mounting support member. Also included are coupling pins coupled on a first end with the detachable mounting support member and coupling on a second end with a front pillar of a vehicle with at least one mounting support member coupling the front pillar trim with the front pillar. A flexible curtain air bag back plate configured to couple between the front pillar trim and the front pillar by the coupling pins and the mounting support member. Also included is an air bag chamber comprising a flexible substantially box shaped chamber open along one side wherein the air bag chamber is coupled with the flexible air bag back plate. 
   In an alternative embodiment the air bag chamber is substantially trapezoidal in cross section. 
   In yet another embodiment the flexible curtain air bag back plate further comprises reinforcing members reinforcing the coupling between the mounting support member and the flexible curtain air bag back plate. The reinforcing member can be substantially a metal washer shaped device. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings: 
       FIG. 1  is a perspective view showing a curtain air bag device assembled within a front pillar panel according to an embodiment of the present invention; 
       FIG. 2  is an exploded perspective view of the curtain air bag device of  FIG. 1 ; 
       FIG. 3  is a cross-sectional view taken along the line III—III in  FIG. 1 ; 
       FIG. 4  is a cross-sectional view taken along the line IV—IV of  FIG. 1 ; and 
       FIG. 5  is a cross-sectional view showing a state in which the curtain air bag device is deployed according to an embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   According to  FIGS. 1–4 , the curtain air bag device according to the present invention is constructed such that a curtain air bag back plate  10  ( FIG. 2 ) into which a curtain air bag A ( FIG. 3 ) is received, is assembled with a front pillar trim  20  and then mounted on a front pillar panel  100  of a side chassis of a car. The curtain air bag back plate  10  includes a hollow type of body  12  ( FIG. 3 ) in which the curtain air bag A is received. The body  12  is cut along the end of one side in a lengthwise direction corresponding to a direction in which the curtain air bag A deploys. The body  12  has a section in the shape of a trapezoid such that the length of one surface on which the cut part is formed is substantially shorter than that of the opposite surface, which enables the curtain air bag A to be easily deployed. The body  12  is integrally formed with one or more first coupling end portions  14  ( FIGS. 2 and 4 ). Each of the first coupling end portions  14  includes a through hole  14   a  through which a second screw  44  of a fixing part  40  and a mounting support member  30  are coupled. The first coupling end portions  14  also include a cut part  14   b , formed on one end of the first coupling end portion  14  and a first coupling hole  14   c  that corresponds to a first coupling pin  24  formed on the other end. 
   It is preferred that the first coupling end portion  14  be formed of a flexible, synthetic resin. Being flexible, a space can be provided through which the curtain air bag A can fully deploy (see  FIG. 5 ). 
   The cut part  14   b  is provided for the purpose of avoiding an interference caused when the first coupling pin  24  of a first detachable mounting support part  22  is assembled with a second coupling hole  103  of the front pillar panel  100  (described below). The cut part  14   b  may be in the form of a hole like the first coupling hole  14   c  and a second coupling hole  15   a  in configurations where no interference occurs. 
   Preferably, the first coupling end portion  14  is provided on both ends of the body  12 . More preferably, between the first coupling end portions  14  are provided one or more second coupling portions  15  on which the second coupling hole  15   a  is formed. 
   A distance ‘d’ between the through hole  14   a  of the first coupling end portion  14  and the first coupling hole  14   c , as shown in  FIGS. 2 and 3 . The distance ‘d’ provides for the movement of the front pillar trim  20  upon the deployment of the curtain air bag A, described in detail below. 
   The front pillar trim  20  includes the first detachable mounting support part  22 . The detachable mounting support part  22  is formed on one surface of the front pillar trim  20  such that it corresponds to the cut part  14   b  and a second detachable mounting support part  25   a  corresponding to the first coupling hole  14   c . First and second coupling pins  24  and  25   b  are disposed on top portions of the first and second detachable mounting support parts  22  and  25   a  such that they can be detachably coupled to the front pillar panel  100 . The front pillar trim  20  also includes a through hole  26  on both ends of the front pillar trim  20 . A coupling support part  28  protrudes adjacent to the through hole  26 . In one embodiment, the coupling support part  28  preferably includes a screw groove formed in the middle of the support part  28 . A first coupling bolt  42  couples the fixing part  40  to the front pillar trim  20 . 
   Each of the mounting support members  30  includes a hollow type of body  32  that has a screw coupling hole  32   a  on one surface and is opened on the other side. Each of the mounting support members  30  further includes a coupling end portion  34  extended from the edge of one side of the body  32 . The coupling end portion  34  has a coupling hole  34   a  that corresponds to the first coupling bolt  42  of the fixing part  40 . 
   Each of the fixing parts  40  include a first coupling bolt  42  passed through the coupling hole  34   a  of each of the mounting support members  30  corresponding thereto and then coupled to the coupling support part  28 . Also included is a second coupling bolt  44  passed sequentially through the through hole  26 , the screw coupling hole  32   a  and the through hole  14   a  corresponding thereto and finally coupled to the corresponding part of the front pillar panel  100 . Referring to  FIGS. 3 and 4 , the center of the screw coupling hole  32   a  formed on the body  32  of each of the mounting support members  30  is desirably placed on the same line as the center of the through hole  26  of the front pillar trim  20 . A stopper  60  ( FIG. 1 ) is adapted to make the through hole  26  of the front pillar trim  20  opened and closed. The stopper  60  includes a plurality of locking end portions  62  formed on one surface to which the through hole  26  is coupled (see  FIGS. 3 to 5 ). A symbol ‘d 1 ’ represents an inner diameter of the through hole  103  of the front pillar panel  100 , symbol ‘d 2 ’ represents a diameter of the second coupling bolt  44 , and ‘s’ represents a distance between the inner diameter of the through hole  103  and the diameter of the second coupling bolt  44 . 
   The rigidity of the first coupling end portion  14  is increased by providing a reinforcing member  50 , preferably made of metal, on the first coupling hole  14   a  ( FIG. 3 ). The reinforcing member  50  has a hollow type of body  52  provided on the inner peripheral surface of the first coupling hole  14   a  and locking end portions  54  extending from the opened portions of both ends of the body  52  in a normal direction, such that the body  52  is not deviated from the through hole  14   a . Hence, the outer diameter of the both ends of each of the locking end portions  54  is designed to be larger than the outer diameter of the first coupling hole  14   a . Preferably, the inner peripheral surface of the reinforcing member  50  is in close contact with the second coupling bolt  44 . The body  52  is preferably provided with a screw thread on the inner peripheral surface thereof such that the screw thread is joined with the second coupling bolt  44 . In use, the reinforcing member  50  is provided to prevent the through hole  14   a  from breaking while the first coupling end portion  14 , assembled with the mounting support member  30 , is deviated upon the deployment of the curtain air bag A. 
   Now, a method of assembling the curtain air bag device according to the present invention will be described. 
   First, the coupling hole  34   a  formed on the coupling end portion  14  of both the mounting support member  30  and the detachable mounting support part  22  are respectively aligned such that the mounting support member  30  and the front pillar trim  20  are coupled to each other by using the first coupling bolt  42 . 
   Next, coupling pins  24 ,  25   b  and  27   b  of the front pillar trim  20  are passed through the cut part and the coupling holes  14   b ,  14   c  and  15   a  of the curtain air bag back plate  10 . Next, the front pillar trim  20  assembled with the curtain air bag plate  10  are aligned with corresponding coupling holes  103 ,  105  and  107  of the front pillar panel  100 . Thereafter, the front pillar trim  20  is secured to the front pillar panel  100  by using the palm of a hand or other tools. At this time, the second coupling bolt  44  is passed through the through hole  14   a  and inserted into the first through hole  101  of the front pillar panel  100 . 
   Finally, the stopper  60  is assembled on the outside of the through hole  26  of the front pillar trim  20 , thereby completing the assembling process of the curtain air bag device of the present invention. 
     FIG. 5  shows a state in which the curtain air bag device is deployed according to the present invention. The first and second coupling end portions  14  and  15  ( FIG. 2 ) of the curtain air bag back plate  10  elastically deform as the curtain air bag A is deployed, such that the curtain air bag A can be fully deployed. 
   The front pillar trim  20  of the present invention is inserted or attached to the top end of a crush pad, such as, for example, the top end of the front pillar trim  20  is slightly deviated or displaced along with the mounting support member  30 , whereas the bottom end thereof is hinge-pivoted on the portion attached to the crush pad. 
   According to an embodiment, the front pillar trim  20  assembled with the curtain air bag back plate  10  is secured to the front pillar panel  100  by the expansion force of the curtain air bag A as the air bag is deployed, and the body  32  is movable with reference to the front pillar panel  100 , such that the front pillar trim  20  moves by the distance that corresponds to the distances ‘d’ and ‘s’ as shown in  FIGS. 2 and 3 . 
   Therefore, with the expansion force of the curtain air bag A as the air bag is deployed, the second coupling bolt  44  and the first coupling end portion  14  are deviated from the front pillar panel  100  by the distance ‘d.’ Furthermore, the front pillar trim  20  is deviated while rotating in a clockwise direction with reference to the second coupling bolt  44  that acts as a stopper during the deployment of the curtain air bag A. More particularly, if both ends of the first coupling end portion  14  are not so deviated as to fully deploy the curtain air bag A, the air bag A is not fully drawn from the lower end of the front pillar trim  20  and even destroyed by the expansion force of the curtain air bag A. Therefore, the fully deployment of the curtain air bag A and the prevention of the deviation of the front pillar trim  20  are determined based on the distances ‘d’ and ‘s’. 
   The forgoing embodiments are merely exemplary and are not to be construed as limiting the present invention. The present teachings can be readily applied to other types of apparatuses. The description of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art.