Patent Publication Number: US-2007096535-A1

Title: Restraint system for a vehicle

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates generally to occupant restraint systems used in motor vehicles, and more specifically to a restraint system incorporating a presenter making it easier for an occupant to grasp and secure the belt.  
      2. Background Art  
      Occupant restraint belt systems (also known as seat belts) are fitted to most types of passenger vehicles in order to protect vehicle occupants from injury during a crash or other abrupt deceleration of the vehicle. One limitation to the effectiveness of modern seat belts is that they require a voluntary and optional act by the occupant to fasten the belt properly around their body. Some persons do not use their vehicle&#39;s seat belts because they find it difficult or inconvenient to don the seat belt.  
      This difficulty in donning the belt is sometimes due to the fact that when the belt is in the unfastened condition, it must assume a stowed position in which it does not obstruct the occupant while entering or exiting the vehicle. Consequently, the seat belt is typically configured so that it is pulled to the rear by a retractor mechanism. With the belt in this stowed position, portions of the belt that the occupant must grasp in order to don the belt may be difficult to see and/or reach when in the seated position.  
      Systems have been proposed for moving a seat belt inwardly and/or forwardly to a more easily grasped position after the occupant is seated in the seat. Examples of such systems are disclosed in U.S. Pat. Nos. 6,550,805 and 6,676,612, which are hereby incorporated by reference. It would be advantageous to provide a restraint system for a vehicle seating area which includes a belt presentation and securement system which assists the user in securing the belt while seated in the vehicle seat.  
     SUMMARY OF THE INVENTION  
      The present invention provides a restraint system for use in a passenger seating area of a motor vehicle. The restraint system includes a seat belt assembly disposed adjacent the passenger seating area which is adjustable between a stowed position and at least one deployed position. The seat belt assembly including a webbing positionable across the body of an occupant extending between a lower anchor mounted adjacent a lower side portion of the seat and a belt retractor disposed adjacent an upper side portion of the seat.  
      An inflatable section disposed within the webbing for presenting the belt assembly is adjustable between a deflated condition and an inflated condition by a source of gas pressure. The gas pressure source is operable to alternatively inflate and deflate the inflatable section. An anchor is disposed opposite the seat belt assembly adjacent the seating area and includes a receiving element adapted to engage and secure the belt assembly.  
      A controller monitors vehicle conditions with one or more sensors. The controller instructs the source of gas pressure to inflate the inflatable section, which positions the belt assembly in a deployed position for grasping by the occupant and/or securement around an occupant in a vehicle when the controller receives a signal from the one or more sensors indicating a change in vehicle conditions.  
      Other features and advantages of the present invention will be readily appreciated and better understood after reading the subsequent description when considered in connection with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a side view of a restraint system for use in a passenger seating area of a motor vehicle in accordance with the present invention;  
       FIG. 2  is a perspective view of the restraint system in combination with a vehicle seat of the present invention;  
       FIG. 3  is a front plan view of the vehicle seating area with the restraint system in a stowed position;  
       FIG. 4  is a perspective view of the vehicle seating area with the restraint system in an activated or deployed position;  
       FIG. 5  is a perspective view of the vehicle seating area with the restraint system in a secured position;  
       FIG. 6  is a schematic view of the restraint system in accordance with the present invention;  
       FIG. 7  is a cross-sectional view of the belt assembly with the inflatable section in a deflated condition;  
       FIG. 8  is a cross-sectional view of the belt assembly with the inflatable section in an inflated condition;  
       FIG. 9  is a cross-sectional view of the belt assembly of the restraint system having an inflatable section in accordance with a second aspect of the present invention; and  
       FIG. 10  is a cross-sectional view of the belt assembly of the restraint system having an inflatable section in accordance with a third aspect of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)  
      Referring now to the Figures, a restraint system incorporating a belt presenter in accordance with the present invention is shown installed in a vehicle having a seating area. It is understood that the restraint system may be used in either the front or rear passenger seating areas. For purposes of this disclosure, the restraint system will be installed in the front passenger seating area.  
      Restraint system  10  includes an associated seat belt assembly  12  incorporated in or disposed adjacent to a vehicle seat  14  or seating area. Vehicle seat  14  is of the type well known in the art. Seat  14  includes a generally upright seat back  16  for supporting the torso of a seated occupant  18  (indicated in phantom lines) and a generally horizontal seat bottom or cushion  20  projecting generally upward and forward from the bottom portion of the seat back  16  for supporting the pelvis and thighs of the occupant  18 .  
      For purposes of description only, the vehicle seat  14  will be referred to herein as having an inboard side and an outboard side, these terms referring to the sides of the seat adjacent to a center of a vehicle and an exterior side of a vehicle respectively, as is the case if the seat is located on the left side of the vehicle. This disclosure applies equally to a seat located at any position within a vehicle.  
      The belt assembly  12  comprises a length of flexible webbing  22  having an upper end secured to an upper anchor  24  adjacent the upper outboard portion  26  of the seat back  16 , and a lower end secured to a lower anchor  28  adjacent the rear portion of the seat bottom  20 . Webbing  22  serves as a main restraint member and includes an inflatable section (not shown) which will be described in greater detail below.  
      When the webbing  22  is inserted over and secured to a buckle or receiving element  30  extending from an anchor  32 , the webbing  22  defines a lap belt and a shoulder belt in a manner well known in the art to restrain the occupant  18  in the event of a crash or other abrupt deceleration of the vehicle. For purposes of description, anchor  32  is shown inboard of the vehicle seat. However, it is understood that the anchor may be positioned inboard or outboard in the three, four or five point belt assemblies.  
      As an alternative, the lap belt and shoulder belt may be formed as separate lengths of webbing connected by a fitting (not shown) that includes a receiving element engageable with the inboard anchor. It is also contemplated that belt restraint system  10  may be used with a three point, four point or five point belt assembly.  
      The upper anchor  24  preferably comprises a belt retractor  34  that may be housed within seat back  16  (as shown in  FIGS. 1 and 2 ), or mounted to a portion of the vehicle structure such as a roof rail or B-pillar as is shown in  FIGS. 3-5  and as is well known in the restraints art. The belt retractor  34 , operative to retract the webbing  22  when it is not fastened about the occupant  18 , provides for adjustment of the length of the belt for varying-sized seat occupants, and properly positions the seat belt restraint system as is well known in the art.  
      The belt retractor  34  may include load limiter and/or belt pretensioner devices (not shown) of the type well known in the restraints art. In one aspect of the present invention, belt retractor  34  includes an electric motor which assists in the deployment of belt assembly  12 . The belt retractor  34  tensions the belt when a spring force is exceeded in response to detection of a possible accident condition, such as vehicle deceleration, which causes the belt to spool out from the retractor. The electric motor, in response to a signal from the controller, automatically spools out webbing as the belt is inflated to overcome the spring force designed into retractor  34  to allow the belt to be presented to a deployed position. The motor may also assist the retractor when retracting the webbing on to the spool.  
      Referring now to  FIGS. 2 and 6 , the restraint system  10  includes a controller  36  that monitors the condition of the seat belt assembly  12 . One or more sensors  38 ,  40 ,  42  are disposed adjacent various portions of the passenger seating area or vehicle seat, including the belt retractor  34  and receiving element  30 . Sensors  38 ,  40 ,  42  are configured to monitor the condition of the belt assembly  12  and receiving element  30 , as well as the occupancy of the vehicle seat  14 .  
      In a preferred aspect of the present invention, sensor  38  monitors the state of belt retractor  34  to determine whether webbing  22  is drawn from a spooled condition in retractor  34  to a use position. Sensor  38  may detect the condition of belt retractor using a variety of sensing methods. For example, a sensor may be incorporated into the belt retractor to detect rotational movement of the retractor. Alternatively, a photocell may be disposed adjacent the belt retractor to sense when the webbing is spooled out from the retractor. In another embodiment, a microswitch senses a change in the diameter of the spooled belt, such that a decrease in diameter indicates a change in condition.  
      Sensor  40  is provided adjacent the receiving element  30  to detect the presence of the webbing  22  placed around the receiving element  30  for securement. It is understood that the controller  36  may monitor conditions of the seat  14  through the use of sensor  42  coupled to other vehicle systems, such as a seat weight sensor, a door status indicator switch, a buckle status switch, combined with or integrated into a pressure bladder and an ignition switch. For example, the controller may transmit a signal to inflate the inflating portion of the seat belt in response to a “seat occupied” indication from seat weight sensor, and/or a “door closed” indication from door condition sensor, and/or in response to an “on” indication from ignition key.  
      Referring now to  FIGS. 3-8 , a description of the belt presentation features of the restraint system of the present invention is described in greater detail. As is illustrated in  FIG. 3 , prior to an occupant being seated in seat  14 , the belt assembly is placed in a stowed position or first position, in which the belt is unfastened and belt retractor (not shown) draws webbing  22  upward so that it extends in a substantially straight line between the upper and lower anchors.  
      In this position, as shown in  FIGS. 3 and 7 , the inflatable section  50  of the belt assembly is in a deflated condition such that the belt is in the stowed position wherein the belt is unfastened and offers little or no interference with the seat occupant entering or exiting the vehicle. In the deflated condition, the inflatable section in webbing  22  does not significantly affect the flexibility of the belt assembly  12 .  
      Receiving element  30  connected to the anchor  32  is disposed adjacent the seat bottom  20 . Receiving element  30  is configured to receive and secure webbing  22  in a secured position. It is contemplated that receiving element  30  may include a buckle element which receives and secures a latch element disposed as the webbing of the belt assembly.  
      As is illustrated in  FIG. 4 , webbing  22  of belt assembly  12  is shown extending at least partially across vehicle seat  14  toward receiving element  30  in an activated or deployed position. The controller  36 , as shown in  FIG. 6 , in response to a signal output from one or more of sensors  38 ,  40 ,  42 , transmits a signal to a pressure source, shown as block  44 . Pressure source  44  may be located anywhere on board the vehicle and preferably comprises a pressure vessel that is recharged by an air compressor (not shown). Alternatively, the pressure source may comprise a vehicle component which supplies pneumatic power to other vehicle systems such as an air suspension system (not shown).  
      In yet another aspect of the present invention, a pressure bladder (not shown) may be disposed within the seat cushion and contain air or another gas. When an occupant sits on seat cushion, the pressure bladder is compressed by the occupant&#39;s body weight, and at least a portion of the gas contained in the bladder is forced into inflatable section, causing the belt assembly to move to the deployed condition.  
      Referring now to  FIGS. 6-8 , a description of the interconnection between an inflatable section  50  in webbing  22  of seat belt assembly  12  and the pressure source  44  is described in greater detail. A valve  46  may be provided to control the flow of gas from the pressure source  44  into a hose  48 . Controller  36  monitors and controls pressure source  44  and/or valve  46  to control the flow of pressurized gas from the pressure source through hose  48  into the inflatable section  50  of belt assembly  12 .  
      Controller  36  activates pressure source  44  and/or valve  46  so as to force gas through hose  48  and into inflatable section  50  after the occupant is seated in the vehicle seat and ready to don the seat belt. The controller may, for example, inflate the belt assembly in response to a “seat occupied” indication from a seat weight sensor, and/or a “door closed” indication from door condition sensor, and/or in response to an “on” indication from ignition key. It is also contemplated that the controller will instruct the valve to allow the inflatable section  50  to deflate upon detection of a secondary condition, such as a period of time elapsing without use of the restraint system, or detection of a “door open” indication from the door condition sensor or an “off” indication from the ignition key.  
      As shown in  FIG. 8 , when inflatable section  50  inflates to present the belt to the occupant, it expands in cross-section so that it is no longer flat and, as a result, becomes substantially more rigid than when deflated. In the deployed condition shown in  FIG. 4 , the inflatable section in webbing  22  causes belt assembly  12  to extend generally forward and inward with respect to the seat  14  and occupant so that the occupant may grasp webbing  22 , pull the belt across his/her body, and secure the webbing  22  to receiving element  30  on the anchor. Movement of the belt to the deployed, graspable condition may require some amount of the webbing  22  to be drawn out of retractor  34 , so inflation of inflatable section  50  must provide sufficient force to overcome the winding force of the retractor. Alternatively, use of an electric motor with the retractor assists in feeding webbing when the inflatable section is inflated to overcome the spring force of the belt retractor and retracting the webbing in the deflated condition.  
      In the deployed condition, belt assembly  12  is preferably adjacent or above the upper surface of the occupant&#39;s thigh and far enough forward and inward for the occupant to easily see and grasp the webbing  22 . The inflatable section remains somewhat flexible and compliant when in the inflated condition so that it does not cause any discomfort to occupant if it contacts the occupant&#39;s body as it extends inward to present the belt. If, due to the geometry of the vehicle seat, anchors, or other vehicle structure, the inflatable section must assume a complicated shape in order to properly position the belt in the deployed condition. This may be achieved by designing the inflatable section to include a variety of shapes and geometries, which will be described in greater detail below.  
      Referring now to  FIG. 5 , belt assembly  12  of restraint system  10  is shown in the secured position. It is contemplated that belt assembly  12  may be secured around receiving element  30  with or without the aid of the seat occupant. In a first aspect of the present invention, when the inflated section in webbing  22  inflates, the belt assembly extends at least partially across the occupant&#39;s body towards the receiving element  30 . The seat occupant grasps webbing  22  and places the webbing  22  over receiving element  30 . Receiving element  30  may comprise an anchor that includes a locking element to secure webbing. Alternatively, the receiving element may include a fixed tether with one or more protruding sections which are designed to engage and secure the webbing.  
      In one aspect of the present invention, the sensor positioned adjacent receiving element  30  detects the presence of the webbing  22  and transmits a signal to the controller. Controller, in response to this signal, commands the valve to open, thereby deflating inflatable section. When the inflatable section at least partially deflates, the belt assembly  12  will secure the occupant within the vehicle seat  14 . It is also contemplated that the controller will instruct the pressure source and/or valve to deflate the inflatable section in the webbing  22  based on the detection of other conditions, including the belt retractor sensor detecting the occupant grasping the belt assembly, expiration of a set time period, or by any other appropriate condition or combination of conditions of vehicle systems.  
      In another aspect of the present invention, the belt assembly  12  may inflate and extend around the receiving element  30  during the inflation process. During this process, the inflatable section fills and expands the webbing such that the webbing extends across the occupant in seat  14  such that the webbing inflates over the receiving element adjacent a locking element  52 . Once positioned in locking element  52 , the controller will transmit a signal to the pressure source and/or valve to at least partially deflate the inflatable section in webbing  22  to secure the occupant in vehicle seat  14 .  
      Referring now to  FIGS. 7-10 , a more detailed description of belt assembly  12  of restraint system  10  is provided. The inflatable section  50  of webbing  22  is attached to the lower anchor of the restraint system. The inflatable section  50  in the inflated condition has an expanded circular shape in cross-section and is more rigid than when in the deflated condition and urges the belt assembly to the at least one deployed position in which the belt is unfastened and is positioned so that the seat occupant may easily grasp the belt to permit fastening of the belt, as shown in  FIG. 4 . It is understood that the inflatable section may be positioned anywhere along the length of the belt, including adjacent an upper belt anchor. An inflatable section disposed adjacent an upper anchor will move so that its lower end moves forward and/or inward when it deploys.  
      In the deflated condition shown in  FIG. 7 , inflatable section  50  and webbing  22  are positioned adjacent one another. In a preferred aspect of the present invention, As shown in  FIG. 8 , inflatable section  50  when inflated has a cross section circumference which is significantly less than that of the surrounding webbing. This difference in width allows inflatable section  50  to freely expand to a generally circular shape in cross-section and to a generally curved shaped longitudinally within the webbing  22  while allowing the webbing  22  to maintain sufficient flexibility to extend from the stowed position to a deployed position.  
      The inflatable section of the belt assembly can be formed by a variety of materials and manufacturing methods. As shown in  FIGS. 7-8 , webbing  22  of belt assembly  12  is formed from a pair of woven strips which are stitched or otherwise secured together to form a recess to receive the inflatable section  50 . The inflatable section  50  is formed from a flexible, impermeable material, such as polyvinyl carbonate (PVC) or polyester. Inflatable section is preferably formed as a pair of strips that are sealed or secured to each other with adhesive or the like to allow for expansion of the material and provide a substantially gas-tight inner chamber. When expanded, the inflation section  50  provides webbing  22  a curved shape optimal for securement to a receiving element provided on the opposite side of the vehicle seat.  
      Referring now to  FIGS. 9 and 10 , alternative embodiments of the inflatable section  50  of the present invention are shown and disclosed.  FIG. 9  illustrates a inflatable section  50  disposed within a webbing  22  of seat belt assembly  12 . Inflatable section  50  includes an inflatable member  54  secured to a structural member  56 . Inflatable member  54  is preferably a one-piece elastic tube which forms an inner chamber therein. Structural member  56  may comprise a polymeric chord which can be either laminated or attached to a portion of the inflatable member  54 . In one aspect of the present invention, the inflatable member  54  inflates to a generally curved shape such that the structural member  56  is longitudinally shorter than the webbing  2  while maintaining more rigidity than webbing  22 . It is also understood that the inflatable member may be shaped based on the amount and application of air pressure entering the inner chamber.  
      As shown in  FIG. 10 , the inflation chamber of inflatable section  50  need not be one large, tubular section, but instead may be divided into multiple sections. Inflatable section  50  comprises a pair of inflatable tubes  58 ,  60 , each defining an inner chamber therein. Tubes  58 ,  60  are laminated together to form inflatable section  50  within webbing  22  of seat belt assembly  12 . The longitudinal curved shape of inflatable section  50  is preferably controlled by application of different pressures in each tube by the pressure source. Alternatively, tubes  58 ,  60  may have distinct elastic properties, allowing one tube to expand into the webbing, allowing the belt to deploy, while the remaining tube retains the desired curved shape. It is understood that tubes  58 ,  60  may be separated from one another, or they may be connected with one another to permit some amount of gas flow between them.  
      Alternatively, it is also possible to fabricate a belt according to the invention wherein the inflatable section is formed integrally with the webbing. This may be accomplished, by manufacturing the webbing as a flat, two-layer, tubular structure in, for example, a “one-piece woven” technique. This type of construction eliminates the need to stitch a separate top layer to the webbing. The upper end of the inflation chamber is defined by stitching or otherwise sealing off the chamber so that the portion of the belt above the stitching does not inflate.  
      The webbing should be manufactured to naturally maintain a flat condition. It is also possible to fabricate the inflatable section as a unit that is separate from webbing, and that is subsequently secured to the webbing. This may be achieved, for example, by fabricating a flexible tube (not shown) with closed ends that is sewn or otherwise secured to webbing in the desired location to define inflatable section.  
      It is also possible for an inflatable section according to the present invention to be maintained in a state of partial inflation at times when it is desired that the belt be in the stowed condition. Inflatable section will be configured such that the partially inflated state gives belt a shape and a degree of rigidity that serves (along with the belt tension provided by belt retractors) to help retain the belt in the desired stowed condition in which it will not interfere with occupants entering and exiting the vehicle. The state of partial inflation may constitute inflation of the same inflation chamber or group of chambers that are used to achieve deployment, but at a reduced pressure. Or the state of partial inflation may constitute inflation of an inflation chamber or a group of chambers separate from those used to achieve deployment. In either case, the controller is programmed to supply pressure to inflatable section in a manner to achieve the partially inflated state at desired times based on inputs from appropriate vehicle systems.  
      While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.