Abstract:
A seatbelt assembly is provided with buckle device having a holder located therein to segregate overlapping sections of the structural wire and/or signal cables.

Description:
BACKGROUND 
   The present invention relates generally to the field of vehicle seatbelts. 
   Seatbelts are installed in vehicles to increase passenger safety. A tongue, which is provided at an end of a seatbelt webbing, is fixed to engage with a buckle device on the floor of the vehicle. When the seatbelt is buckled the passenger is constrained by the seatbelt. 
   As disclosed for example in Japanese Patent Publication No. 2002-321593 (incorporated by reference herein) a seatbelt apparatus may include a wire strap. The wire-strap type buckle includes a buckle section with an opening at one end for inserting the tongue therein. The buckle section includes latch members that engage the inserted tongue; the buckle section is supported on both sides by a U-shaped frame so as to enable rotation of the buckle. The latch members are provided with two switches, one on a “hall” side and another on a “substrate” side for detecting engagement between the tongue and buckle. 
   Within the enclosure of the buckle, both ends of a wire are bent into two parts so as to form a loop (with overlapping portions) rotatably mounted to the vehicle floor. The looped portion of the wire is rotatably supported by a fixed member on the vehicle floor so that the enclosure is supported on the floor of the vehicle body and may swing freely therefrom. A protective cover (or boot) of an accordion shape is mounted between the enclosure and the fixed member for storing the wire and/or signal cables connected to the switches. 
   When a passenger engages the tongue of the seatbelt to the buckle device, an upper end of the buckle device is pulled in the longitudinal (or fore/aft direction) by a tensile force applied to the seatbelt. Therefore, the protective cover and the wire in the protective cover are bent in the longitudinal direction with respect to the vehicle. At this time, as shown in  FIG. 6   a - 6   b , for example, a portion of the protective cover  18  is significantly bent at an acute angle causing a concentrated bending stress in that area. The wire  14  may be significantly bent or crossed at a portion near the corresponding area(s) of the protective cover  18 . 
   Accordingly, it is desirable to provide a seatbelt apparatus that can prevent the wire from being bent excessively or portions of the wire from intertwining when the seatbelt is buckled. 
   SUMMARY 
   In one exemplary embodiment a seatbelt apparatus includes a seatbelt having a tongue and a buckle configured to engage with the tongue. The buckle may include a switch configured for sensing engagement between the buckle section and the tongue. A wire is configured for fixing the buckle device to a vehicle body side. A protective cover, covers an outer side of the wire so as to house the wire. A signal cable may be connected to the switch and extends on an inner side of the protective cover. A holder may be located on the inner side of the protective cover and fitted on the outer side of the wire. 
   It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only, and are not restrictive of the invention as claimed. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other features, aspects, and advantages of the present invention will become apparent from the following description, appended claims, and the accompanying exemplary embodiments shown in the drawings, which are briefly described below. 
       FIG. 1  is a schematic depiction of a seatbelt apparatus according to an exemplary embodiment. 
       FIG. 2  is a schematic depiction of a buckle device according to an exemplary embodiment. 
       FIG. 3  is a schematic depiction of a side cross-sectional view of the buckle device of  FIG. 2 . 
       FIG. 4  is a cross-sectional view taken along the line  4 - 4  in  FIG. 2 . 
       FIG. 5  is a schematic depiction of a buckle device according to an exemplary embodiment. 
       FIG. 6   a  is a schematic depiction of a prior art buckle device in a design position. 
       FIG. 6   b  is a schematic depiction of a prior art buckle device in a use position. 
   

   DETAILED DESCRIPTION 
   The seatbelt assembly  1  includes a seatbelt  4  with tongue  9 , a buckle device  10  having a buckle section  12  configured to engage with the tongue  9  and a set of switches  13   a ,  13   b  for sensing engagement between the buckle section and the tongue. Also provided is a wire  14  for fixing the buckle device  10  to the vehicle body frame. A protective cover  18  on an outer peripheral side of the wire encloses (or stores) the wire  14 . A signal cable  17  is connected to the switches  13   a ,  13   b  and extends on the inner peripheral side of the protective cover  18 . A holder  19  is located on the inner peripheral side of the protective cover  18  and fitted on the outer periphery of the wire  14 . 
   An upper end of the buckle device  10  is pulled in the longitudinal (or fore-and-aft) direction with respect to the vehicle. The protective cover  18  and the wire  14  encased in the protective cover are bent in the longitudinal direction when the seatbelt  4  is worn or buckled. The holder  19  is fitted on the outer periphery of the wire  14  on the inner peripheral of the protective cover  18 . The protective cover  18  and wire  14  are restricted from bending at a sharp acute angle. Therefore, the stress concentration factor within the wire  14  can be significantly reduced by the inclusion of the holder  19  in the seatbelt assembly  1 . Excessive bending of the wire or crossing of the parts of the wire can be prevented by inclusion of the holder  19 . 
   The protective cover  18  is configured to rotate (or swing freely) with respect to the vehicle floor. The wire  14  is fixed at each end of the enclosure  11  of the buckle device  10 . In one exemplary embodiment, the wire  14  includes a bent end pivotably coupled to or supported by a fixed member  8  (or anchor) coupled to the vehicle frame or the vehicle seat. The protective cover  18  is formed into an accordion shaped member (or boot) which supports the enclosure  11  and enables the buckle device  10  to rotate. The holder is located within the cover or enclosure and covers the wire to thereby provide additional rigidity to the wire when the enclosure is subject to a bending moment in a plane extending in the longitudinal direction of the vehicle. 
   The upper end of the buckle device  10  is rotatable in the longitudinal direction with respect to the vehicle. The holder  19  resists the bending moment resulting from the buckle device  10  rotating with respect to the vehicle floor and thereby reduces the stress concentration factor in the wire  14 . In one exemplary embodiment, the holder  19  is fitted on the wire  14  at a portion of the protective cover  18  proximate a constricted portion of the protective cover  18  located on the fixed member  8  side. Bending of the wire  14  at the constricted portion on the fixed member  8  side can reliably be alleviated with the implementation of the holder  19 . Hence excessive bending of the wire  14  can reliably be prevented. In one exemplary embodiment, an adhesive tape  20  is wound around the holder  19  and the wire  14  so as to fix the holder  19  to the wire  14 . 
   Referring now to the figures, particularly to  FIG. 1 , the seatbelt assembly  1  for use with a driver or passenger seat in a motor vehicle in shown. The seatbelt apparatus  1  includes a seatbelt (webbing)  4  which is supported at one end by an anchor  2  fixed to the vehicle floor. A retracting device  3  is coupled to the seatbelt at the other end and fixed to the vehicle floor. The retracting device applies pressure to the seatbelt which is configured to be retracted while constraining the occupant. A midsection of the seatbelt  4  is passed through a shoulder anchor  5  rotatably held at a position on a center pillar (not shown) of the vehicle body. In the illustrated exemplary embodiment, the center pillar is attached to an upper side of the vehicle body. The tongue  9  is attached to the seatbelt  4  below the shoulder anchor  5 . The buckle device  10  is connected to a fixed side member  8  provided on a side of a seat (not shown) opposite the anchor  2 . The seatbelt assembly  1  is fixed to the vehicle floor. The fixed side member  8  may be provided on a floor side of the vehicle body. 
   In one exemplary embodiment, the buckle device  10  includes a buckle section  12  having a flat enclosure  11  opened at one end for inserting the tongue  9  (as shown in  FIG. 2  to  FIG. 5 ). The buckle section  12  includes latch members configured to engage the tongue  9  when inserted into the enclosure  11  from an opening  11   a  at one end. The latch members are supported on both sides of a base  12   a  in a U-shaped frame to enable rotation. The latch members are provided with two switches  13   a ,  13   b  on a hall side and a substrate side for detecting engagement with the tongue. 
   The wire  14  is folded into at least two parts so as to form a loop pivotably secured at each end in the enclosure  11  via a wheel  16 . The wire  14  is pivotably supported by the fixed member  8  on the side of the seat via a wheel  16 . A looped portion  14   a  on the bent end of the wire  14  is wound around the wheel  16 . The protective cover  18  is mounted between the enclosure  11  and the fixed member  8  for storing the wire  14  and signal cables  17  connected to the switches  13   a,    13   b . When the occupant buckles the seatbelt  4 , the upper end of the buckle device  10  is pulled in the longitudinal direction by the seatbelt. The protective cover  18  and the wire  14  are bent in the longitudinal direction of the vehicle. 
   In one exemplary embodiment, the holder  19  is a resilient member composed of aluminum or resin. In another exemplary embodiment, the holder  19  is fitted on the wire  14  in the vicinity of the constricted portion  18   a  of a lower section of the protective cover  18 . An adhesive tape  20  is wound around the holder  19  so as to ride across the wire  14 , so that the holder  19  is fixed to the wire  14 . Accordingly, the holder  19  and the wire  14  can be fixed reliably in a simple method. 
   The holder  19  provides support to the wire  14 , as shown in  FIG. 5 . The holder  19  prevents the protective cover  18  and the wire  14  from being significantly bent at an acute angle in the vicinity of the protective cover  18 . Bending stresses are less concentrated and the wire  14  is prevented from being excessively bent or crossed with each other. 
   The priority application, Japanese Patent Application No. 2005-205078, filed on Jul. 14, 2005, is hereby incorporated by reference herein in its entirety. 
   Given the disclosure of the present invention, one versed in the art would appreciate that there may be other embodiments and modifications within the scope and spirit of the invention. For example, the teachings herein can be applied to any seatbelt assembly and are not limited to a three-point seatbelt assembly.