Abstract:
An occupant protection system includes a side air bag to be inflated at a side of an occupant in a vehicle, a curtain sheet situated adjacent to a window opening at the side of the occupant, and an actuation device attached to the curtain sheet. The curtain sheet is generally located away from a position covering the window opening. The actuation device is operated in an emergency situation, to cover the window opening by the curtain sheet to support the side air bag.

Description:
BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT  
       [0001]     The present invention relates to an occupant protection system for protecting an occupant in a vehicle when the vehicle is involved in a side collision or turns on a side.  
         [0002]     A side air bag device and curtain air bag device are known as an occupant protection system for protecting an occupant by preventing the occupant from hitting a side door when a vehicle is involved in a side collision or turns on a side (for example, see Patent References 1 and 2). In this specification, turning on a side includes a rollover. 
        Patent Reference 1: Japanese Patent Application Publication (Kokai) No. 10-175499     Patent Reference 2: Japanese Patent Application Publication (Kokai) No. 2000-62562        
 
         [0005]     An object of the present invention is to provide an occupant protection system having a side air bag device and a curtain sheet disposed in a limited space in a vehicle for effectively protecting an occupant in an event of a side collision or turning on a side.  
         [0006]     Further objects and advantages of the invention will be apparent from the following description of the invention.  
       SUMMARY OF THE INVENTION  
       [0007]     In order to attain the objects described above, according to a first aspect of the present invention, an occupant protection system includes a side air bag to be inflated at a side of an occupant of a vehicle. The occupant protection system further includes a curtain sheet situated away from a position covering a window at a side of a seat in a normal state and to be deployed to cover the window from a cabin side of the vehicle in an emergency state.  
         [0008]     According to a second aspect of the invention, in the occupant protection system in the first aspect, the side air bag is inflated at least at a side of a portion between a hip and a head of the occupant.  
         [0009]     According to a third aspect of the invention, in the occupant protection system in one of the first and second aspects, the curtain sheet has an upper portion secured to a chassis above the window. A pulling device pulls a lower portion of the curtain sheet to be deployed to cover the window.  
         [0010]     According to a fourth aspect of the invention, in the occupant protection system in the third aspect, a linear member is mounted along the lower portion of the curtain sheet. One end of the linear member is fixed to the chassis, and the pulling device pulls the other end of the linear member.  
         [0011]     According to a fifth aspect of the invention, in the occupant protection system in one of the third and fourth aspects, the pulling device is provided with a stopper for preventing the pulling device from retracting after being pulled.  
         [0012]     According to a sixth aspect of the invention, in the occupant protection system in one of the first to fifth aspects, the curtain sheet is situated between the side air bag and the window when the side air bag is completely inflated and the curtain sheet is completely deployed.  
         [0013]     In the present invention, when a vehicle having the occupant protection system is involved in a side collision or turns on a side, the curtain sheet is deployed along the window at a side of the seat, and the side air bag is inflated on a cabin side of the curtain sheet, so that the side air bag receives the occupant to absorb an impact. Even when the window is open or broken, the curtain sheet prevents the side air bag from moving out of the window, thereby effectively absorbing the impact. The curtain sheet also holds the occupant inside the cabin of the vehicle.  
         [0014]     In the present invention, the occupant protection system includes the curtain sheet instead of a curtain air bag device. Accordingly, it is possible to retain the occupant protection system in a space in the vehicle smaller than that of a curtain air bag device.  
         [0015]     In the present invention, the occupant protection system preferably includes the side air bag to be inflated at least at a side from the hip to the head of the occupant. Accordingly, it is possible to receive an entire side portion of the occupant sitting on the seat with the side air bag, thereby effectively protecting the occupant.  
         [0016]     In the present invention, the curtain sheet may have the upper portion secured to the chassis above the window, and the pulling device may pull the lower portion of the curtain sheet, so that the curtain sheet is deployed to cover the window. When the pulling device pulls the curtain sheet, it is possible to quickly deploy the curtain sheet even when the curtain sheet slides on a pillar of the chassis.  
         [0017]     In the present invention, the linear member may be provided along the lower portion of the curtain sheet. One end of the linear member is fixed to the chassis, and the pulling device pulls the other end of the linear member. Accordingly, it is possible to stretch the curtain sheet with the linear member so that the lower portion is pulled with a sufficient tensile force (so that the lower portion is tightly stretched).  
         [0018]     In the present invention, the pulling device may have the stopper for preventing the curtain sheet from retracting after the curtain sheet is pulled. Accordingly, the deployed curtain sheet is held under high tension, thereby effectively receiving the side air bag and the occupant for long time. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]     FIGS.  1 ( a ) and  1 ( b ) are perspective views showing an occupant protection system according to an embodiment of the present invention;  
         [0020]     FIGS.  2 ( a ) and  2 ( b ) are perspective views showing an occupant protection system according to another embodiment of the present invention; and  
         [0021]     FIGS.  3 ( a ) and  3 ( b ) are perspective views showing an occupant protection system according to a further embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0022]     Hereunder, embodiments of the present invention will be described with reference to the drawings. FIGS.  1 ( a ) and  1 ( b ) are perspective views of a front seat in a car provided with an occupant protection system according to an embodiment, respectively.  FIG. 1 ( a ) shows a state before a side air bag is inflated and a curtain sheet is deployed, and  FIG. 1 ( b ) shows a state after the side air bag is inflated and the curtain sheet is deployed.  
         [0023]     As shown in FIGS.  1 ( a ) and  1 ( b ), a seat  10  in the car includes a seat cushion  11 , a seat back  12 , and a headrest  13 . A shoulder anchor (not shown) is provided on a B-pillar  16 , and a shoulder belt is hung on the shoulder anchor. The shoulder belt is attached to a buckle  14  via a tongue. A side air bag device  20  includes a side bag  21  to be inflated along a front door  22  and an inflator (not shown) for inflation, and is provided at the front door  22  or the seat  10  (the seat  10  in the embodiment).  
         [0024]     A curtain sheet device  30  extends from an A-pillar  15  of the car to a C-pillar  17  through a roof side rail  18 . In a case of a side collision or rolling, a curtain sheet  31  is deployed between the A-pillar  15  and the C-pillar  17  to cover windows  22   a  and  23   a  of the front door  22  and a rear door  23 . The curtain sheet  31  is folded up in an elongated form, and is disposed along the roof side rail  18  while a shape is held by, for example, a breakable tape. The curtain sheet  31  is covered with a roof head lining (not shown).  
         [0025]     A plurality of lugs  31   a  projects from an upper portion of the curtain sheet  31 . The lugs  31   a  are fastened to the A-pillar  15  and the roof side rail  18  by, for example, bolts or rivets. A lower portion of the curtain sheet  31  is turned up and sewn to form a tunnel-shaped rope extending portion  31   b . A rope  32  extends through the rope extending portion  31   b . A front end of the rope  32  is connected to the bottom of the A-pillar  15  via a rope anchor  33 , and a rear end thereof is connected to the top of the C-pillar  17  via a rope anchor  34 .  
         [0026]     In the embodiment, the curtain sheet device  30  includes a guide rail  35  mounted on the C-pillar  17  as a pulling device for pulling the curtain sheet  31  downwardly and extending the curtain sheet  31  vertically; a slider  36  slidable along the guide rail  35 ; an actuator  37  for moving the slider  36  with a pressure of gas; and a one-way clutch  38  provided at the bottom of the guide rail  35 . The actuator  37  includes a gas generator, and a multistage piston (not shown) extending along the guide rail  35  by a pressure of gas from the gas generator. When the gas generator is activated, the piston extends to push the slider  36 , so that the slider  36  moves along the guide rail  35 . When the slider  36  reaches a lower end of the guide rail  35 , the slider  36  is latched with the one-way clutch  38 , thereby being prevented from retracting upwardly.  
         [0027]     The rear end of the rope  32  drawn out of a rear end of the rope extending portion  31   b  is hooked to the slider  36  and connected to the rope anchor  34 .  
         [0028]     When the car provided with the side air bag device  20  and the curtain sheet device  30  thus constructed is involved in a side collision or turns on its side, the actuator  37  and the inflator of the side air bag device  20  are activated. Upon the activation of the actuator  37 , the slider  36  moves along the guide rail  35 , and pushes down the rear portion of the rope  32 , thereby stretching the curtain sheet  31 , as shown in  FIG. 1 ( b ). The curtain sheet  31  pushes a side edge of the roof head lining open, and stretches downwardly along the cabin sides of the windows  22   a  and  23   a . In a state in which the slider  36  is latched by the one-way clutch  28 , the rope  32  is tightly extended between the slider  36  and the rope anchor  33 , and the curtain sheet  31  covers the windows  22   a  and  23   a  of the doors  22  and  23 .  
         [0029]     Upon the activation of the inflator of the side air bag device  20 , the side air bag  21  is inflated at a side of a part between the hip and head of an occupant on the seat  10 . The side air bag  21  is inflated and situated on the cabin side of the deployed curtain sheet  31 . Since the inflated side air bag  21  receives the occupant from the side, the impact applied to the occupant is absorbed.  
         [0030]     The deployed curtain sheet  31  covers the windows  22   a  and  23   a , even when the window glasses of the doors  22  and  23  are open or broken. Accordingly, the occupant remains inside the car. The deployed curtain sheet  31  also backs up the inflated side air bag  21 , and prevents the side air bag  21  from moving toward the outside of the car.  
         [0031]     While the multistage actuator  37  using the gas generator as a driving power source is adopted in the embodiment, a piston-shaped slider may be directly moved by the blow pressure of gas from the gas generator. FIGS.  2 ( a ) and  2 ( b ) show an example of such a method. A cylinder-shaped guide rail  40  extends in the front-rear direction of the vehicle body at the bottom of a C-pillar  17 . A piston-shaped slider  41  is placed inside a guide rail  40 . A rear end of a rope  32  is connected to the slider  41 . At least the rear end of the rope  32  is heat resistant. An end of the rope  32  is guided into the guide rail  40  by a sheave  42 .  
         [0032]     A front end of the guide rail  40  is closed by a head end plate. The head end plate has an insertion hole (not shown) for inserting the rope  32 . A gas generator  43  is connected to the guide rail  40  to supply gas between the head end plate and the slider  41 . A one-way clutch  44  is provided at a rear end of the guide rail  40 .  
         [0033]     When the gas generator  43  is activated, the slider  41  moves rearward along the guide rail  40  until it is latched with the one-way clutch  44 , as shown in  FIG. 2 ( b ). Consequently, the rope  32  is tightly deployed, and the curtain sheet  31  is deployed to cover windows  22   a  and  23   a . A side air bag  20  operates in a manner similar to that in the embodiment described above. In this embodiment, advantages similar to those in the above embodiment are obtained.  
         [0034]     While the guide rail  40  extends laterally in FIGS.  2 ( a ) and  2 ( b ), the guide rail  40  may extend vertically so that the end thereof at the one-way clutch  44  is placed on the upper portion. FIGS.  3 ( a ) and  3 ( b ) show a structure according to a further embodiment, in which expandable chambers  50  and  51  are provided in a curtain sheet  31 A. A gas generator  53  supplies gas to the expandable chambers  50  and  51  to be inflated, and a rope  32  is pulled by the force of inflation.  
         [0035]     As shown in  FIG. 3 ( b ), the chamber  50  extends in the front-rear direction of the vehicle body along an upper portion of the curtain sheet  31 A. The gas generator  53  is connected to a rear end of the chamber  50  via a duct  54 . The chamber  51  is branched from the chamber  50  at a longitudinal midpoint, extends downwardly through almost the center of a window  23   a , and reaches a lower portion of the curtain sheet  31 A.  
         [0036]     Sheaves  56 ,  57 , and  58  are provided at the bottom of the C-pillar  17  in the rear of a roof side rail  18 . A rope  32  extending from a rear end of a rope extending portion  31   b  is hung on the sheave  56 , is hung on the sheaves  57  and  58  provided above the window  23   a , and is guided into the chamber  51 . The rope  32  extends inside the chamber  51 , and is connected at the tail end to the curtain sheet  31 A near the lower end of the chamber  51 . A one-way rope clutch  59  is provided between the sheaves  56  and  57  to allow the rope  32  only to move from the sheave  56  to the sheave  57 .  
         [0037]     When the gas generator  53  is activated, gas blown from the gas generator  53  flows straight, and first inflates the chamber  50 . A roof lining covering the curtain sheet  31 A is thereby pushed open, and a space is formed between the roof lining and a side portion of the vehicle body. The gas flows from the chamber  50  into the chamber  51 , and the chamber  51  expands downwardly through the space. A portion of the curtain sheet  31 A adjoining the chamber  51  also stretches downwardly through the space while being dragged by the chamber  51 . With the downward expansion of the chamber  51 , the tail end of the rope  32  is pulled downwardly, and the entire curtain sheet  31 A is deployed downwardly through the space. Finally, in a stretch finished state shown in  FIG. 3 ( b ), the curtain sheet  31 A covers the windows  22   a  and  23   a . In this state, the rope  32  is latched with the rope clutch  59 , and is held under high tension.  
         [0038]     Other structures in FIGS.  3 ( a ) and  3 ( b ) are similar to those in the above embodiments, and the same reference numerals denote the same components.  
         [0039]     The embodiment provides advantages similar to those in the above embodiments. The embodiment is also advantageous in that the chamber  51  receives the head of the occupant on a rear seat and absorbs an impact.  
         [0040]     The above embodiments are exemplary embodiments of the present invention, and the present invention may also include embodiments other than the illustrated embodiments. For example, a wire, a belt, a soft resin rod, or a tube may be used as a linear member, instead of the rope. The pulling device is not limited to the one using the gas generator as a power source, and, for example, a motor and a linear solenoid may be used as the power source.  
         [0041]     The disclosure of Japanese Patent Application No. 2004-252630, filed on Aug. 31, 2004, is incorporated in the application.  
         [0042]     While the invention has been explained with reference to the specific embodiments of the invention, the explanation is illustrative and the invention is limited only by the appended claims.