Abstract:
A seat belt anchorage system for securing an inflatable seat belt in a vehicle has an inflator generating inflation-fluid and supplying the fluid through a fluid distribution member to a fluid receiving tube connected to the inflatable seat belt. The system shown being fully self-contained, that is not relying on external power, is adaptable to be secured to the vehicle during the initial manufacture of a vehicle or can be field retrofitted on existing vehicles. The seat belt anchorage system may be secured to the seat, seat back, seat frame, vehicle floor or vehicle structural member. The inflator is either coupled by a conduit or directly connected to the fluid distribution member. Of course if external power is available, the only portion of the anchorage system that will be changed is the configuration of the control of the inflator. Therefore, this system is transparent to the type and style of inflator devices.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of Invention  
           [0002]    This invention relates to safety restraint systems in general and more particularly to systems for anchoring an inflatable seat belt assembly including the inflator, inflatable and seat belt to a passenger position in a vehicle be it a land, sea or air vehicle.  
           [0003]    2. Description of the Related Art  
           [0004]    Inflatables such as air bags in most vehicles rely on a single forward placed sensor for determining when and the severity of a crash of the vehicle. In most instances, the crash is a frontal crash causing the occupants due to inertia to continue in the direction of the vehicle movement. In automobiles, for instance, the sensor and the inflator for the inflatable are generally located forward of the occupant. Although in some instances, such as Inflataband™ restraint systems, available from Universal Propulsion Company, Phoenix, Arizona, the inflator may be located in various positions around the occupant including behind him in the seat back, above him in the roof rails and below him in the seat. In such instances, the sensor can be located in proximity of the inflator or in the front of the vehicle.  
           [0005]    In large capacity vehicles such as buses and airplanes, wherein there are rows of seats for occupants, it is desirable to have self-contained, i.e. all in one, inflation systems at each occupant seat position. This is so because the crash event may cause sequential peak deceleration signals to occur at different seating positions due to the time that it takes the signal to transverse through the vehicle. The first or beginning signal occurs at the time that the vehicle receives its first sudden deceleration signal and continuing in sequence through the transverse length of the vehicle.  
         SUMMARY OF INVENTION  
         [0006]    It is a principle advantage of the present invention to provide a seat belt anchorage system containing an inflator, an inflatable and the various sensing systems necessary to protect the occupant in the event of a sudden deceleration of the vehicle.  
           [0007]    It is yet another advantage of the present invention to have a seat belt anchorage system that is adapted to be retrofitted to existing seats.  
           [0008]    It is still another advantage of the present invention to have a seat belt anchorage system that appears to the vehicle occupant to be nothing more than a seat belt system that is similar to all previous systems the occupant has used in vehicles such as automobiles, airplanes, etc.  
           [0009]    It is yet still another advantage of the present invention to have a self-contained seat belt anchorage system to sense the crash deceleration signal at each occupant seating location as the crash signal or crash pulse travels the distance from the initial signal reception point to an aft seating position. The timing of such travel distance is in dozens of milliseconds after the initial reception of the crash pulse to the detection of the crash pulse at the aft occupant seating position.  
           [0010]    These and other advantages will become apparent in a seat belt anchorage for securing an inflatable seat belt to a seat in a vehicle. The anchorage has a fluid distribution member. The fluid distribution member is operatively connected to a source of inflatable fluid for distributing the inflation fluid. A chamber member is coupled to the fluid distribution member to receive the inflation fluid from the fluid distribution member. The chamber member is secured to the seat by a mounting member rotatively mounted in a position proximate the intersection of and outboard of the seat back member and the seat member of the seat. Attached to the fluid distribution member is an Inflator to provide an inflation fluid or gas that exits the inflator through its outlet to the fluid distribution member. These and other advantages of the present invention will become apparent from the following detailed description including the following drawings. 
       
    
    
     DESCRIPTION OF THE DRAWINGS  
       [0011]    In the drawings:  
         [0012]    [0012]FIG. 1 is side view of the seat belt anchorage system mounted on a seat frame;  
         [0013]    [0013]FIG. 2 is a perspective view of a fluid distribution member;  
         [0014]    [0014]FIG. 3 is a top view of an air chamber;  
         [0015]    [0015]FIG. 4 is a sectional view taken along line  4 - 4  in FIG. 3;  
         [0016]    [0016]FIG. 5 is a sectional view taken along line  5 - 5  in FIG. 3;  
         [0017]    [0017]FIG. 6 is a perspective view of the bracket supporting the air chamber;  
         [0018]    [0018]FIG. 7 is an enlarged sectional view of the air chamber with the inflatable seat belt system attached thereto;  
         [0019]    [0019]FIG. 8 is a schematic view of the inflator control system; and  
         [0020]    [0020]FIG. 9 is a front view, partially in section of a portion of the seat and the inflatable system. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0021]    Referring to the Figs by the characters of reference there is illustrated in FIG. 1 a fragmentary side view of a vehicle seat  10  such as is found in aircraft vehicles. To this seat  10  there is added a seat belt anchorage system  12  that is adapted to be fitted to an existing vehicle seat  10 . The anchorage system has an inflator  14 , a conduit member  16  including the necessary fittings connected to the inflator, a fluid destribution member  18 , a chamber member or an air chamber  20  and a mounting member  22  to secure the air chamber  20  to the vehicle seat  10 . The inflator  14  may be that as shown and described in co-pending patent application assigned to a common assignee and entitled High Thermal Efficiency Inflator and Passive Restraints Incorporating Same which is a continuation-in-part of co-pending U.S. application Ser. No. 08/587,773, filed Dec. 22, 1995 and having Docket Number 9424-50.  
         [0022]    The inflator  14  is securely mounted to the vehicle seat  10  at location that is below or beside the cushion  24  or seat bottom portion of the seat and proximate the intersection of the seat back  26  and the seat cushion  24 . As an alternative embodiment, the inflator  14  can be securely mounted to any structural member of the vehicle such as a pillar or the floor. Typically the inflator  14  is mounted on the vehicle seat  10  and below and to the rear of the seat cushion  24  so as to be out of the way of the occupant and also, out of the way of the occupant in the row behind. Another position of the inflator  14  is its attachment to the separator member, not shown, between adjacent seats in a seating row such as found in the passenger cabin of an airplane.  
         [0023]    The output  28  of the inflator  14 , through which inflation fluid or gas passes, is connected by a conduit member  16  to the fluid distribution member  18 . The conduit is typically a metal tube although other tubing materials such as reinforced rubber or plastic may be used. The function of the conduit member  16  is to conduct the inflation fluid from the inflator  14  to the fluid distribution member  18  wherever it is located.  
         [0024]    Referring to FIG. 2, there is illustrated the fluid distribution member  18  of the preferred embodiment. The member  18  is a stepped diameter tubular member  30  having an inlet  32  at one end connected to the conduit member  16 . The opposite end of the member  18  is closed. At each end of the tubular member  30  there are bearing surfaces  34 ,  36  and circumferentially extending slots  38 ,  40  to locate and hold O-rings  42 . As will hereinafter be shown, the O-rings  42  function to seal the fluid distribution member  18  and the chamber  20 . Located around the perimeter of the intermediate section of the member is a plurality of radially extending orifices  44 . These orifices  44  extend in a direction that is orthogonal to the axis of the tubular member and function to direct the flow of the inflation fluid from inside the member  30  to the outside.  
         [0025]    The inflation fluid leaves the output  28  of the inflator  14  at a relatively high pressure and flows through the conduit member  16  and into the fluid distribution member  18 . Since the member  18  is closed at the end opposite the inlet  32 , the inflation fluid is directed out of the radially extending orifices  44 . The cross-sectional area of the various parts of the system described, i.e. the output  28  of the inflator  14 , the conduit member  16  and the fluid distribution member  18  increases in the direction of fluid flow. The number and the size of the orifices  44  determines the cross-sectional area to the passage of the inflation fluid from the fluid distribution member  18 . In the present embodiment, the fluid distribution member  18  has sufficient cross-sectional area in the orifices along with the orientation of the orifices  44  to cause the fluid distribution member  18  to be thrust-neutralized to the flow and force of the inflation-fluid. The orifices  44  allow the inflation fluid to change its flow direction approximately ninety degrees and into a much larger flow area of the air chamber  20 .  
         [0026]    Referring to FIGS.  3 - 5 , here is Illustrated the air chamber  20  of the preferred embodiment. As will be shown, the air chamber  20  and the fluid distribution member  18  rotate relative to each other or are integrally connected to rotate as a unit. In the preferred embodiment, the air chamber  20  being connected to the seat belt assembly  55  must rotate as the seat occupant moves the seat belt webbing  70 . In an alternate embodiment, both the air chamber and the fluid distribution member are integral or of an unitary construction so that the complete device comprising the fluid distribution member  18  and the air chamber  20  rotate relative to the mounting bracket  22 .  
         [0027]    As illustrated in FIG. 4, the air chamber  20  has an elongated tubular member  48  that has an inside diameter equal to the diameter of the bearing surfaces  34 ,  36  of he fluid distribution member  18 . This permits the two, the fluid distribution member  18  and the air chamber  20 , to be free to relatively rotate while maintaining the seal formed by the O-rings  42 . Intermediate the ends of the elongated member there is a slot  50  which opens the inside of the tubular member  48  to an elongated output section or nozzle  46  of the air chamber  20 .  
         [0028]    [0028]FIG. 5 is a cross-sectional view of the air chamber  20  showing the nozzle shape of the output section. The nozzle  46  is basically a rectangular cross-section having an extended height extending away from the tubular member portion  48 . At the outlet end of the nozzle  46  there is a ridge or a rim  52  that extends around the outside surface of the nozzle  46 . The ridge or rim  52  defines the outer limits of a flat surface  54  between the rim  52  and a similar ridge  56  of substantially equal height at the tubular member  48 . This flat surface  54 , as will hereinafter be shown, supports the seat belt assembly  55 .  
         [0029]    Again the cross-sectional area of the inside of the nozzle  46  is greater than the cross section area of the slot  50  and the total of the areas of the orifices  44  of the fluid distribution member  18 . As the inflation fluid leaves the output  28  of the inflator  14 , each new section has a cross-sectional area that is larger than the previous cross-sectional area, each new cross-sectional area is less than twice the preceding cross-sectional area. This reduction in the cross-sectional area reduces the pressure of the inflation fluid at each step and minimizes the formation of deleterious shock waves.  
         [0030]    The mounting member  22  is illustrated in FIG. 6 and is a generally U-shaped member having a base  58 , a pair of outwardly extending arms  60 ,  62  and a back member  63 . The mounting member or bracket  22  is rotatively mounted to the vehicle seat  10  or seat frame at its base  58  via mounting hole  61  or back member  63  via mounting hole  65  and functions to locate the seat belt assembly  55 . Prior to a crash, when the seat belt assembly  55  experiences a crash event, the mounting member  22  rotates relative to the vehicle seat  10 , seat frame, or vehicle structural member. This rotation facilitates a more even transfer of the load from the air chamber  20  to the seat belt assembly  55 . In the alternate embodiment, the air chamber  20  and the fluid distribution member  18  being integral, axially rotate about an axis extending through the bearing holes  64 ,  66  in the outwardly extending arms  60 ,  62  of the mounting member  22 .  
         [0031]    The fluid distribution member  18  is inserted in one of the bearing holes  64  or  66  in the arms  60 ,  62 . The air chamber member  20  is then slid over the fluid distribution member  18  including its O-rings  42 . The end of the fluid distribution member  18  is then inserted in the other bearing hole  66  or  64  in the other arm  62  or  60  and secured there by a c-clip  68  or other similar holding device.  
         [0032]    In the alternative, the fluid distribution member  18  maybe a multiple piece member, such as a two piece member. Each piece is terminated in a threaded portion. The air chamber member  20  is then inserted between the two arms  60 ,  62  with the tubular member  48  in line with the two bearing holes  64 ,  66  of the bracket  22 . Then each piece of the fluid distribution member  18  is inserted respectively through the two bearing holes in the arms of the bracket and then threaded together in a leak tight manner. C-clips  68  are used to secure the threaded assembly of the fluid distribution member  18  and the air chamber  20  in the bracket  22 .  
         [0033]    Prior to putting the air chamber  20  together with the fluid distribution member  18 , a seat belt assembly  55  is secured to the flanged nozzle  46  of the air chamber  20 . Referring to FIG. 7. there is illustrated how the seat belt assembly  55  for an inflatable seat belt is securely connected to the air chamber flanged nozzle  46 . The seat belt assembly  55  is described and claimed in co-pending patent application having a BFG docket number 1990027 and entitled Inflatable Air Bag For An Inflatable Restraint System and assigned to a common assignee and is incorporated herein by reference.  
         [0034]    As illustrated, the inflatable seat belt assembly  55  in the preferred embodiment has an elongated seat belt webbing  70  that is mounted to the air chamber nozzle  46  at one end of the seat belt webbing  70 . The other end of the seat belt webbing  70  extends to the other side of the seat wherein it typically has a tongue and buckle arrangement  72  with the buckle generally fixedly secured by some flexible means to the vehicle seat  10 . The seat belt webbing  70  has an inflatable member  74  mounted thereto intermediate its ends between the air chamber  20  and the tongue member  72 . As this portion of the assembly is not the subject of the invention, it is not shown here. In essence, the operation of the Inflatabelt™ system as far as an occupant hooking up is the same as in all previous uses of a seat belt.  
         [0035]    Since the subject of this application is an inflatable seat belt anchorage system  12 , the inflatable member  74  must be connected to receive inflation-fluid from the inflator  14 . The air chamber nozzle  46  directs the inflation fluid through an inflatable-fluid receiving tube or snout  76  that is mounted on one surface of the seat belt webbing  70  and connected to the inflatable member  74 .  
         [0036]    In FIG. 7, illustrates one way of connecting the inflatable seat belt assembly  55  to the air chamber  20 . The snout  76  is pulled over the outer rim  52  of the nozzle  46  and lies along the flat surface  54  between the outer rim  52  and an inner ridge or rim  56 . The fit between the snout  76  and the nozzle  46  is one that is substantially leak-tight. As described in the co-pending patent application, the seat belt webbing  70  has mounted to it the snout  76  and the inflatable member  74 . Thus, the webbing  70  is placed over the snout  76  and in order to secure the webbing  70  and to hold it against the high loads that it will be applied. The webbing  70  is then wrapped around the end of the air chamber  20 . The webbing  70  is then brought back to the outer rim  52  on the other side of the nozzle  46  where by means of a pin member  80  it is fed to the back of the air chamber  20 . The webbing  70  is typically bonded  81  to the air chamber  20 . However, it may not be bonded to the air chamber  20  if the designer feels that the clamping assembly  82  is strong or tight enough to hold the high seat belt loads that will develop when the inflatable member  74  is inflated.  
         [0037]    In the preferred embodiment, a frangible tubular cover  78  encloses the inflatable member  74 , the snout  76  and the seat belt webbing  70 . This frangible tubular cover  78  is shown and claimed in co-pending U.S. patent application having Ser. No. 09/099,858 filed on Jun. 18, 1998 by Hammer et al. and entitled Belt System with Inflatable Section Within an Outer Belt Section and Method of Restraint. This co-pending application is incorporated herein by reference.  
         [0038]    The frangible tubular cover  78  then pulled over the webbing  70  on the nozzle  46  up to the inner ridge or rim  56 . The clamping assembly  82  is placed around the frangible tubular cover  78 , the webbing  70  and the snout  76  to secure them to the nozzle  46 .  
         [0039]    The clamping assembly  82 , as illustrated in FIG. 7 comprises a metal band  84  that overlies a flat surface member  86  in order that the band  84  does not damage the frangible tubular cover  78 . The band  84  is tightened to keep the seat belt assembly  55  on the air chamber nozzle  46  when the inflation fluid flows to the inflatable member  74 . Forces in the range of  700  pounds or  318  Kilograms are experienced when the inflatable is inflated to restrain the occupant.  
         [0040]    This fully assembled air chamber  20  with the seat belt assembly  55  is then slipped on the fluid distribution member  18 , in a manner as previously described, and secured between the upright arms  60 ,  62  of the mounting bracket  22 . The mounting bracket  22  is secured to the vehicle seat  10  or a vehicle structure as previously mentioned. The air chamber  20  and fluid distribution member  18  are able to rotate as an integral or unitary member about an axis through the bearing holes  64 ,  66  of the mounting bracket  22 . The rotation follows the movement of the seat belt assembly  55  as an occupant secures the inflatable seat belt assembly about his or her waist. This is illustrated in FIG. 9 wherein the seat belt assembly is illustrated as extending from one side of the vehicle seat  10  to the other side of the vehicle seat. In FIG. 9, the occupant is not shown for purposes of clarity and the seat belt assembly  55  is rotated for better illustration.  
         [0041]    In the preferred embodiment, the control circuit  91  of the inflator  14  is similar to that schematically illustrated in FIG. 8. Inside the faraday shield housing  88  of the inflator, beginning at the end opposite the outlet  28  of the inflator  14 , there is a safety or arming switch  90 . The switch is ready for arming when the seat belt anchorage system  12  is bolted to the vehicle seat  10  and ready for operation. To arm the switch  90 , the setscrew  92  is removed. This switch  90  is represented as a single pole double throw switch wherein the normally open contact  94  is connected to one side of the firing capacitor  96  and the single pole  98  is connected to the other side of the capacitor  96 . In this manner, with the setscrew  92  in place, the firing capacitor  96  is shorted out and will not be charged.  
         [0042]    The normally closed contact  100 , which is held open by the setscrew  92 , is connected to the battery  102 . The battery  102  has a shelf-life of many years. This long life predisposes that there is not an external power source and the inflator  14  must be in place for a long time to supply the necessary power to the several circuit elements when a sudden deceleration of the vehicle or a crash occurs.  
         [0043]    These elements include a crash or acceleration sensor or switch  104  that will detect a sudden deceleration of the vehicle indicating the need for or conditions indicating the need for the deployment of the inflatable to protect the occupant. The sensor  104  is initially adjusted for working in the various force environments such as found in automobiles, airplanes, etc. The output of the control circuit of the inflator  14  is a squib  106  for igniting the propellant within the inflator. The control circuit  91  is enclosed in a faraday shield  88  in the inflator  14  for preventing external signals from activating the inflator elements.  
         [0044]    The details of the inflator  14  are not subject of this application other than how it is assembled in the system  12 . The inflation fluid has passed through a burst disk in the inflator  14  and through the conduit member  16 . The inflatable fluid distribution member  18  receives the fluid from the conduit member and directs the fluid to the air chamber  20 . From the air chamber  20  the inflation-fluid is delivered through the snout  76  to the inflatable member  74 .  
         [0045]    There has thus been shown and described an inflatable seat belt anchorage system for securing an inflatable seat belt to a seat in a vehicle. The vehicle can be an automobile, a bus, an airplane or any vehicle that carries occupants and that may be subject to sudden decelerations caused by a crash or similar action. It is to be appreciated that the seat belt anchorage system  12  can be used with inflatable seat belts of configurations other than those shown and described herein and with other crash or acceleration sensors and inflator systems.