Abstract:
A tension sensing assembly for a seat restraint system in a vehicle is provided. The tension sensing assembly comprises an anchor, a movable mechanism configured to be secured to a portion of a buckle, at least one magnet coupled to the movable mechanism, a Hall effect sensor coupled to the anchor, at least one tension spring secured to the anchor at a first end and the movable mechanism at a second end. The movable mechanism moves the at least one magnet relative to the Hall effect sensor to induce an output from the Hall effect sensor. The output indicates a tension level being applied to the tension sensing assembly.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     The present invention claims the priority date of copending U.S. Provisional Patent Application Ser. No. 60/464,761, filed Apr. 23, 2003. 
    
    
     TECHNICAL FIELD 
     The present invention relates generally to seat restraint systems for vehicles and, more particularly, to a tension sensing assembly for a seat restraint system in a vehicle. 
     BACKGROUND OF THE INVENTION 
     It is known to provide a seat restraint system such as a seat belt in a vehicle to restrain an occupant in a seat of the vehicle. In some vehicles, the seat restraint system may be a lap belt, a shoulder belt, or both. Typically, the lap belt and shoulder belt are connected together at one end. The seat restraint system includes a latch plate at the connected end. The seat restraint system also includes a buckle connected at one end by webbing or the like to vehicle structure. The buckle receives the latch plate to be buckled together. When the buckle and latch plate are buckled together, the seat restraint system restrains movement of the occupant to help protect the occupant during a collision. 
     Smart inflatable restraint systems need to know what is occupying a seat of the vehicle. Decisions on deployment of inflatable restraints depend on information supplied by sensors in the seat in determining weight of an object in the seat. When a child seat is placed in the seat and cinched down, the sensors may read a large mass instead of a child seat. With this condition, there will be high tension in the seat restraint system. Comfort studies have shown that no human occupant would wear their seat restraint that tight. With this information on seat restraint tension, the inflatable restraint system can decide on deployment of the inflatable restraints. 
     Conventional belt tension sensors typically include compression springs for sensing capability. However, these compression springs do not provide adequate sensing capability at low tension levels. In addition, these tension sensors may exhibit rattle noise and have a relatively large package size. Further, these tension sensors may be subject to environmental contamination. Additionally, these tension sensors have an inability to be packaged on either an inboard side or outboard side of a passenger seat of the vehicle. Also, these tension sensors are not compatible with buckle pretensioners. 
     Therefore, it is desirable to provide an assembly for sensing tension in a seat restraint system of a vehicle. It is also desirable to provide an assembly for sensing tension in a seat restraint system in a vehicle that allows a control module to decide on deployment of the inflatable restraints. It is further desirable to provide an assembly for sensing tension in a seat restraint system in a vehicle that provides an indication of low-tension forces in the seat restraint system. It is still further desirable to provide an assembly for sensing tension in a seat restraint system having a smaller package size. Therefore, there is a need in the art to provide a tension sensing assembly that meets these desires. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention is a tension sensing assembly for a seat restraint system in a vehicle including at least one anchor for operative connection to vehicle structure. The tension sensing assembly also includes a movable mechanism for operative connection to a buckle assembly of the seat restraint system. The tension sensing assembly includes at least one magnet operatively supported by the movable mechanism and a Hall effect sensor operatively supported by the at least one anchor and cooperable with the at least one magnet. The tension sensing assembly further includes at least one tension spring extending between the at least one anchor and the movable mechanism. The movable mechanism moves the at least one magnet relative to the Hall effect sensor to change an output of the Hall effect sensor to indicate a tension level in the seat restraint system when the at least one tension spring is stretched. 
     One advantage of the present invention is that a new tension sensing assembly is provided for a seat restraint system in a vehicle. Another advantage of the present invention is that the tension sensing assembly may be mounted on a buckle or inboard side of the vehicle or an anchor or outboard side of the vehicle. Yet another advantage of the present invention is that the tension sensing assembly incorporates at least one tension spring that provides low tension sensing capability (0 to 30 lb.). Still another advantage of the present invention is that the tension sensing assembly is compatible with a buckle pretensioner. A further advantage of the present invention is that the tension sensing assembly provides a reduction in overall package size and reduces the amount of parts. Yet a further advantage of the present invention is that the tension sensing assembly has a reduced number of wire-harness breakouts and electrical connectors. Still a further advantage of the present invention is that the tension sensing assembly has reduced component, system, and material costs. Another advantage of the present invention is that the tension sensing assembly reduces rattle noise. Yet another advantage of the present invention is that the tension sensing assembly has a plastic overmold to prevent environmental contamination. Still another advantage of the present invention is that the tension sensing assembly improves performance by eliminating friction caused by webbing sliding against sensor body. A further advantage of the present invention is that the tension sensing assembly may incorporate a cable attachment to provide flexible presentation of the buckle assembly and allows for attachment to a pretensioner, if required. Yet a further advantage of the present invention is that the tension sensing assembly may incorporate a flexible cable to reduce bending moment due to inboard loading and allows the tension sensing assembly to stay in line with the buckle assembly. 
     Other objects, features, and advantages of the present invention will be readily appreciated, as the same becomes better understood, after reading the subsequent description taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a tension sensing assembly, according to the present invention, illustrated in operational relationship with a seat restraint system of a vehicle. 
         FIG. 2  is a perspective view of the tension sensing assembly of  FIG. 1 . 
         FIG. 3  is an exploded perspective view of the tension sensing assembly of  FIGS. 1 and 2 . 
         FIG. 4  is a sectional view taken along line  4 - 4  of  FIG. 2 . 
         FIG. 5  is a sectional view taken along line  5 - 5  of  FIG. 2 . 
         FIG. 6  is an exploded perspective view of another embodiment, according to the present invention, of the tension sensing assembly of  FIG. 1 . 
         FIG. 7  is a partial fragmentary elevational view of a portion of the tension sensing assembly of  FIG. 6 . 
         FIG. 8  is a perspective view of yet another embodiment, according to the present invention, of the tension sensing assembly of  FIG. 1 . 
         FIG. 9  is a perspective view of still another embodiment, according to the present invention, of the tension sensing assembly of  FIG. 1 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings and in particular  FIG. 1 , one embodiment of a tension sensing assembly  10 , according to the present invention, is shown for a seat restraint system, generally indicated at  12 , in a vehicle (partially shown), generally indicated at  14 . The vehicle  14  includes a vehicle body  16  and a seat  18  mounted by suitable means to vehicle structure such as a floorpan (not shown) in an occupant compartment  20  of the vehicle body  16 . In this embodiment, the seat  18  is a front seat of the vehicle  14 . It should be appreciated that the seat  18  could be a rear, second row, or third row seat for the vehicle  14 . 
     Referring to  FIG. 1 , the vehicle  14  includes the seat restraint system  12  for restraining an occupant (not shown) in the seat  18 . The seat restraint system  12  includes a latch tongue or plate  22  connected to belt webbing  23  at an end of either one of a lap belt, shoulder belt, or both which have another end connected to a retractor (not shown). The seat restraint system  12  also includes a buckle assembly  24  for receiving the latch plate  22 . The buckle assembly  24  is connected by suitable means such as belt webbing  25  to the tension sensing assembly  10 . The tension sensing assembly  10  is connected to vehicle structure in a manner to be described. It should be appreciated that the tension sensing assembly  10  may be mounted on either an inboard side or outboard side of the seat  18  of the vehicle  14 . It should also be appreciated that the latch plate  22  is engageable and disengageable with the buckle assembly  24 . It should further be appreciated that, except for the tension sensing assembly  10 , the seat restraint system  12  and vehicle  14  are conventional and known in the art. 
     Referring to  FIGS. 1 through 5 , the tension sensing assembly  10 , according to the present invention, includes a lower anchor  26  extending longitudinally. The lower anchor  26  has an anchor portion  28  that is generally planar and rectangular in shape. The anchor portion  28  has a mounting aperture  30  extending therethrough to act as a mounting hole for a function to be described. The lower anchor  26  has a base portion  32  extending generally perpendicular to the anchor portion  28  and a tongue portion  34  extending generally longitudinally from the base portion  32 . The base portion  32  and tongue portion  34  are generally rectangular in shape. The tongue portion  34  has a slot  36  extending therethrough for a function to be described. The lower anchor  26  is made of a metal material. It should be appreciated that the anchor portion  28  is offset from the tongue portion  34  and can be customized if required for in-vehicle packaging. 
     The tension sensing assembly  10  includes a moveable mechanism  96  comprising at least one, preferably a pair of upper anchors  38  extending longitudinally. Each upper anchor  38  has an anchor portion  40  that is generally planar and rectangular in shape. The anchor portion  40  has a mounting aperture  42  extending therethrough to act as a mounting hole for a function to be described. Each upper anchor  38  has a base portion  44  extending generally perpendicular to the anchor portion  40  and a tongue portion  46  extending generally longitudinally from the base portion  44 . The base portion  44  and tongue portion  46  are generally rectangular in shape. The tongue portion  46  has an aperture  48  extending therethrough and a counterbore  49  disposed about the aperture  48  for a function to be described. Each upper anchor  38  has a projection  50  on one side of the base portion  40  and a cavity  52  on the other side of the base portion  40  to locate the upper anchors  38  relative to each other. Each upper anchor  38  is made of a metal material and overmolded with a plastic material to protect bearing surface from environmental contamination. 
     The tension sensing assembly  10  includes a fastener  54  to secure the upper anchors  38  and lower anchor  26  together. The fastener  54  is of a rivet type having a head portion  56  and a shaft portion  58 . The shaft portion  58  extends through the apertures  48  in the upper anchors  38  and the slot  36  in the lower anchor  26 . The head portion  56  is disposed in the counterbore  49  of one of the upper anchor  38  and the free end of the shaft portion  58  is expanded to form another head portion  56  that is disposed in the counterbore  49  of the other upper anchor  38 . The fastener  54  is made of a metal material. It should be appreciated that the fastener  54  is fixed to the upper anchors  38  and the slot  36  in the lower anchor  26  allows for longitudinal motion of the lower anchor  26  relative to the upper anchors  38 . It should be appreciated that the fastener  42  is conventional and known in the art. 
     The tension sensing assembly  10  includes a plurality of spring mounts  60  extending longitudinally from the upper anchors  38  and the lower anchor  26 . Preferably, each upper anchor  38  has one spring mount  60  on one side on the base portion  40  and the lower anchor  26  has a pair of spring mounts  60  spaced laterally on the base portion  28 . 
     The tension sensing assembly  10  also includes at least one, preferably a plurality of, more preferably two, springs  62  extending between the upper anchors  38  and the lower anchor  26 . The springs  62  are tuned to a predetermined force for a high-tension condition to have an output of approximately eight pounds (8 lb.) to approximately thirty pounds (30 lb.). The springs  62  are of a coil type having a first end connected to the spring mounts  60  of the lower anchor  26  by suitable means such as spring crimps  64  and a second end connected to the spring mounts  60  of the upper anchors  38  by suitable means such as spring crimps  64 . The springs  62  are made of a spring material. It should be appreciated that the springs  62  are tensioned when the lower anchor  26  is moved relative to the upper anchors  38 . 
     Referring to  FIGS. 3 and 4 , the tension sensing assembly  10  includes at least one, preferably a plurality, more preferably a pair, of magnet  66  disposed in recesses  68  of the upper anchors  38 . One of the magnets  66  is disposed in the recess  68  on the tongue portion  46  of one of the upper anchors  38  and the other magnet  66  is disposed in the recess  68  on the tongue portion  46  of the other one of the upper anchors  38 . The magnets  66  are spaced laterally from each other. The magnets  66  are mounted on the tongue portions  46  of the upper anchors  38 , preferably molded or die-cast into the tongue portions  46  of the upper anchors  38  and charged during assembly. 
     The tension sensing assembly  10  also includes a Hall effect sensor  70  disposed in a recess  72  of the tongue portion  34  of the lower anchor  26 . The Hall effect sensor  70  is spaced longitudinally between the magnets  66  and is mounted on a printed circuit board  74  connected to the base portion  32  and is potted or encapsulated and connected by electrical leads or wires  76  to a source of power such as a controller (not shown) of the vehicle. The Hall effect sensor  70  and magnets  66  are moved relative to each other during a high-tension condition. It should be appreciated that the magnets  66  and Hall effects sensors  70  are moved relative to each other in a pull-pull arrangement. It should also be appreciated that the position of the magnets  66  relative to the hall effect sensors  70  changes the output signal. It should be appreciated that the Hall effect sensor  70  is preferably centered between the magnets  66 . 
     The tension sensing assembly  10  includes a cover  78  disposed over the tongue portions  34  and  46  of the upper anchors  38  and the lower anchor  26 . The cover  78  is a generally rectangular tubular member. The cover  78  may be made of either a plastic or metal material. It should be appreciated that the cover  78  is disposed between the base portions  40  and  32  of the upper anchors  38  and the lower anchor  26 . 
     When installed in the vehicle  14  as illustrated in  FIG. 1 , the tension sensing assembly  10  has the belt webbing  25  extending through the anchor portions  40  of the upper anchors  38 . The tension assembly  10  has the anchor portion  28  of the lower anchor  26  connected to vehicle structure such as the floorplan, by suitable means such as an anchor bolt  80 . 
     In operation of the tension sensing assembly  10 , when the latch plate  22  is not latched with the buckle assembly  24 , the Hall effect sensor  70  transmits a no tension signal. 
     When the occupant buckles the seat restraint system  12 , the tension in the belt webbing  25  is lower than a predetermined load required to deflect the spring  62 . In this state, the tension sensing assembly  10  will send an output signal to the controller. The controller uses the output signal for weight compensation along with a weight signal from a bladder (not shown) in the seat  18  to decide on deployment of an inflatable restraint (not shown). It should be appreciated that the seat restraint system  12  is in a low-tension condition. It should also be appreciated that the tension sensing assembly  10  function similar to a load cell to measure load and send the signal to the controller. 
     When a child seat (not shown) is placed in the seat  18  and the seat restraint system  12  is buckled, the belt webbing  23  is cinched to pull the child seat tightly into the seat  18 . As the tension is increased in the belt webbing  25 , the contact force on the upper anchors  38  via the belt webbing  25  increases. The resistive force of the springs  62  reacts against the increased tension. When the tension in the belt webbing  25  exceeds the predetermined load, the upper anchors  38  move as the springs  62  are stretched, thereby moving the magnets  66  relative to the Hall effect sensor  70  in a pull-pull arrangement. This movement changes the output of the Hall effect sensor  70 . The translation of the magnets  66  is in proportion to the force due to the springs  62 . The controller uses the output signal for weight compensation along with a weight signal from a bladder (not shown) in the seat  18  to decide on deployment of an inflatable restraint (not shown). It should be appreciated that the seat restraint system  12  is in a high-tension condition. It should also be appreciated that an audible tone or visual indication may be provided when the tension in the belt webbing  25  is increased above a predetermined level. It should further be appreciated that the tension sensing assembly  10  could be used as an analogue device. 
     Referring to  FIGS. 6 and 7 , another embodiment, according to the present invention, of the tension sensing assembly  10  is shown for the seat restraint system  12  in the vehicle. Like parts of the tension sensing assembly  10  have like reference numerals increased by one hundred (100). In this embodiment, the tension sensing assembly  110  reduces components by eliminating the upper anchors, cover, and one magnet, while reducing package height. The tension sensing assembly  110  includes the lower anchor  126  as a strap having the anchor portion  128  and aperture  130 . The lower anchor  126  also includes the base portion  132  and the tongue portion  134  with the slot  136 . The tension sensing assembly  110  also includes a movable mechanism  196  comprising a housing  190  and a buckle frame  180  of the buckle assembly  24 . The buckle frame  180  has a base wall  182  and a pair of opposed side walls  184  extending generally perpendicular to the base wall  182 . The buckle frame  180  includes a tongue portion  186  extending longitudinally from the base wall  182  and having an aperture  187  extending therethrough for a function to be described. The tongue portion  186  also has a pair of opposed recesses  188  for a function to be described. 
     The housing  190  of the tension sensing assembly  110  cooperates with the buckle frame  180  and the lower anchor  126 . The housing  190  is generally rectangular in shape and is made of a die-cast material. The housing  190  has an aperture  191  extending therethrough for a function to be described. The housing  190  also includes a pair of opposed tabs  192  extending outwardly therefrom to be received in the recesses  188  of the buckle frame  180 . 
     The tension sensing assembly  110  also includes a housing  190  to cooperate with the buckle frame  180  and the lower anchor  126 . The housing  190  is generally rectangular in shape and is made of a die-cast material. The housing  190  has an aperture  191  extending therethrough for a function to be described. The housing  190  also includes a pair of opposed tabs  192  extending outwardly therefrom to be received in the recesses  188  of the buckle frame  180 . 
     The tension sensing assembly  110  includes the fastener  154  to secure the housing  190  and lower anchor  126  together. The fastener  154  has the head portion  156  and the shaft portion  158 . The shaft portion  158  extends through the aperture  191  in the housing  190 , the slot  136  in the lower anchor  126 , and the aperture  187  in the buckle frame  180 . It should be appreciated that the fastener  154  is fixed to the housing  190  and buckle frame  180  and the slot  136  in the lower anchor  126  allows for longitudinal motion of the lower anchor  126  relative to the housing  190  and buckle frame  180 . 
     The tension sensing assembly  110  includes the spring mounts  160  extending longitudinally from the buckle frame  180  and the lower anchor  126 . The buckle frame  180  has a pair of spring mounts  160  spaced laterally on the base wall  182  and the lower anchor  126  has a pair of spring mounts  160  spaced laterally on the base portion  128 . 
     The tension sensing assembly  110  also includes the springs  162  extending between the buckle frame  180  and the lower anchor  126 . The springs  162  have a first end connected to the spring mounts  160  of the lower anchor  126  by suitable means such as spring crimps  164  and a second end connected to the spring mounts  160  of the buckle frame  180  by suitable means such as spring crimps  164 . It should be appreciated that the springs  162  are tensioned when the lower anchor  126  is moved relative to the buckle frame  180  and housing  190 . 
     The tension sensing assembly  110  includes a magnet  166  disposed in a recess  193  of the housing  190 . The magnet  166  is die-cast into the housing  190  and charged during assembly. 
     The tension sensing assembly  110  also includes the Hall effect sensor  170  disposed in a recess  172  of the tongue portion  134  of the lower anchor  126 . The Hall effect sensor  170  is mounted on the printed circuit board  174  connected to the base portion  132  and is potted or encapsulated and connected by electrical leads or wires  176  to a source of power such as a controller (not shown) of the vehicle. The Hall effect sensor  170  and magnet  166  are moved relative to each other during a high-tension condition. The operation of the tension sensing assembly  110  is similar to the tension sensing assembly  10 . 
     Referring to  FIG. 8 , yet another embodiment, according to the present invention, of the tension sensing assembly  10  is shown for the seat restraint system  12  in the vehicle. Like parts of the tension sensing assembly  10  have like reference numerals increased by two hundred (200). In this embodiment, the tension sensing assembly  210  is integrated with the buckle assembly  24 . The tension sensing assembly  210  includes a buckle frame  280  of the buckle assembly  24 . The buckle frame  280  has a base wall  282  and a pair of opposed side walls  284  extending generally perpendicular to the base wall  282 . The buckle frame  280  includes an aperture (not shown) extending through the base wall  282  for a function to be described. 
     The tension sensing assembly  210  also includes a housing  290  to cooperate with the buckle frame  280 . The housing  290  is generally rectangular in shape. The housing  290  has an aperture (not shown) extending therethrough for a function to be described. 
     The tension sensing assembly  210  includes at least one, preferably a pair of cable anchors  292  extending longitudinally. Each cable anchor  292  has an anchor portion  293  that is generally planar and rectangular in shape. The anchor portion  293  has a mounting aperture (not shown) extending therethrough to act as a mounting hole for a function to be described. Each cable anchor  292  has a tongue portion  294  extending generally longitudinally from the anchor portion  293 . The tongue portion  294  has an elongated slot (not shown) extending therethrough for a function to be described. Each cable anchor  292  is made of a metal material. 
     The tension sensing assembly  210  includes a fastener  295  to secure the cable anchors  292  together. The fastener  295  has a head portion  296  and a shaft portion (not shown). The shaft portion extends through the apertures in the cable anchors  292 . The end of the shaft portion is expanded to form another head portion  296  on the other side of the cable anchors  292 . 
     The tension sensing assembly  210  further includes a flexible cable  298  extending between the cable anchors  292  and cooperating with the cable anchors  292  for attachment to vehicle structure. The cable  298  is made of a flexible metal material such as steel. The cable  298  extends between the cable anchors  292  and about the fastener  295  and forms a generally arcuate portion about the fastener  295 . The free ends of the cable  298  are disposed outside of the cable anchors  292  and may be attached to vehicle structure or to a pretensioner (not shown). 
     The tension sensing assembly  210  includes the fastener  254  to secure the housing  290 , cable anchors  292 , and buckle frame  280  together. The fastener  254  has the head portion  256  and the shaft portion  258 . The shaft portion  258  extends through the aperture in the housing  290 , the slot in the cable anchors  292 , and the aperture in the buckle frame  280 . It should be appreciated that the fastener  254  is fixed to the housing  290  and buckle frame  280  and the slot in the cable anchors  292  allows for longitudinal motion of the cable anchors  292  relative to the housing  290  and buckle frame  280 . 
     The tension sensing assembly  210  includes the spring mounts  260  extending longitudinally from the buckle frame  280  and the cable anchors  292 . The buckle frame  280  has a pair of spring mounts  260  speed laterally and extending from the side walls  284  and the cable anchors  292  have a pair of spring mounts  260  spaced laterally and extending from the anchor portion  293 . 
     The tension sensing assembly  210  also includes the springs  262  extending between the buckle frame  280  and the cable anchors  292 . The springs  262  have a first end connected to the spring mounts  260  of the cable anchors  292  by suitable means such as spring crimps  264  and a second end connected to the spring mounts  260  of the buckle frame  280  by suitable means such as spring crimps  264 . It should be appreciated that the springs  262  are tensioned when the cable anchors  292  are moved relative to the buckle frame  280  and housing  290 . 
     The tension sensing assembly  210  includes a magnet  266  disposed in a recess (not shown) of the housing  290 . The magnet  266  is molded or die-cast into the housing  290  and charged during assembly. 
     The tension sensing assembly  210  also includes the Hall effect sensor  270  disposed in a recess (not shown) of the tongue portion  294  of the cable anchors  292 . The Hall effect sensor  270  is mounted on the printed circuit board  274 , which is connected to the base wall  282  of the buckle frame  280  and is potted or encapsulated and connected by electrical leads or wires (not shown) to a source of power such as a controller (not shown) of the vehicle. The Hall effect sensor  270  and magnet  266  are moved relative to each other during a high-tension condition. The operation of the tension sensing assembly  210  is similar to the tension sensing assembly  10 . 
     Referring to  FIG. 9 , still another embodiment, according to the present invention, of the tension sensing assembly  10  is shown for the seat restraint system  12  in the vehicle. Like parts of the tension sensing assembly  10  have like reference numerals increased by three hundred (300). In this embodiment, the tension sensing assembly  310  is integrated with the buckle assembly  24 . The tension sensing assembly  310  includes a buckle frame  380  of the buckle assembly  24 . The buckle frame  380  has a base wall  382  and a pair of opposed side walls  384  extending generally perpendicular to the base wall  382 . The buckle frame  380  includes an elongated slot (not shown) extending through the base wall  382  for a function to be described. It should be appreciated that the buckle frame  380  has a continuous “U” shaped cross-section to provide resistance to bending loads. 
     The tension sensing assembly  310  includes at least one, preferably a pair of anchors  338  extending longitudinally. Each anchor  338  has an anchor portion  340  that is generally planar and rectangular in shape. The anchor portion  340  has a mounting aperture  342  extending therethrough to receive the belt webbing  25 . Each anchor  338  has a tongue portion  346  extending generally longitudinally from the anchor portion  340 . The tongue portion  346  is generally rectangular in shape. The tongue portion  346  is disposed between the side walls  384  of the buckle frame  380 , which provide guidance and side-to-side control of the anchors  338 . The tongue portion  346  has an aperture  348  extending therethrough and a counterbore  349  disposed about the aperture  348  for a function to be described. Each anchor  338  is made of a metal material and overmolded with a plastic material to provide webbing protection and to protect bearing surfaces from environmental contamination. It should be appreciated that the overmold surfaces interface the buckle frame  380  for control of the relative motion and to provide a low friction surface for translation. 
     The tension sensing assembly  310  includes the fastener  354  to secure the anchors  338  and buckle frame  380  together. The fastener  354  has the head portion  356  and the shaft portion  358 . The shaft portion  358  extends through the apertures  348  in the anchors  338  and the slot in the buckle frame  380 . It should be appreciated that the fastener  354  is fixed to the anchors  338  and the slot in the buckle frame  380  allows for longitudinal motion of the anchors  338  relative to the buckle frame  280 . 
     The tension sensing assembly  310  includes the spring mounts  360  extending longitudinally from the buckle frame  380  and the anchors  338 . The buckle frame  380  has a pair of spring mounts  360  spaced laterally and extending from the side walls  384 . Preferably, each anchor  338  has one spring mount  360  on one side thereof. 
     The tension sensing assembly  310  also includes the springs  362  extending between the buckle frame  380  and the anchors  338 . The springs  362  have a first end connected to the spring mounts  360  of the anchors  338  by suitable means such as spring crimps  364  and a second end connected to the spring mounts  360  of the buckle frame  380  by suitable means such as spring crimps  364 . It should be appreciated that the springs  362  are tensioned when the anchors  338  are moved relative to the buckle frame  380 . 
     The tension sensing assembly  310  includes a magnet  366  disposed in a recess (not shown) of the tongue portion  346  of the anchors  338 . The magnet  366  is molded or die-cast into the anchors  338  and charged during assembly. 
     The tension sensing assembly  310  also includes the Hall effect sensor  370  mounted on the printed circuit  374 , which is connected to the base wall  382  of the buckle frame  380  and is potted or encapsulated and connected by electrical leads or wires (not shown) to a source of power such as a controller (not shown) of the vehicle. The Hall effect sensor  370  and magnet  366  are moved relative to each other during a high-tension condition. The load path of the tension load in the restraint system  12  is transferred through the seat belt webbing  23  to the latch plate  22 , buckle latch, buckle frame  380 , anchors  338 , belt webbing  25 , and to the buckle anchor. The operation of the tension sensing assembly  310  is similar to the tension sensing assembly  10 . 
     During assembly, the buckle frame  380  is placed into an injection mold along with the printed circuit board  374  and an encapsulating material to create a subassembly. The printed circuit board  374  has the Hall effect sensor  370  along with resistors (not shown) and capacitors (not shown). It should be appreciated that the process of encapsulating the printed circuit board  374  onto the buckle frame  380  attaches, locates, and protects the Hall effect sensor  370 . 
     The present invention has been described in an illustrative manner. It is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than of limitation. 
     Many modifications and variations of the present invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the present invention may be practiced other than as specifically described.