Abstract:
The invention relates to a belt reel ( 10 ) for a seat belt of a vehicle, said reel comprising a plastic base body ( 22 ) with a receiving chamber ( 26 ) that contains a belt strap pin ( 34 ) for securing a belt strap ( 36 ). In said reel, a first end ( 52 ) of the belt strap pin ( 34 ) is directly supported on the base body ( 22 ) of the belt reel ( 10 ) and a second end ( 56 ) of the belt strap pin ( 34 ) is secured in a separate receiving part ( 54 ) that is attached to the base body ( 22 ).

Description:
RELATED APPLICATIONS 
       [0001]    This application corresponds to PCT/EP2013/002785, filed Sep. 16, 2013, which claims the benefit of German Application No. 10 2012 018 263.5, filed Sep. 17, 2012, the subject matter, of which are incorporated herein by reference in their entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The invention relates to a belt reel for a seat belt of a vehicle, including a base body composed of plastic that which has a receiving space, in which a belt strap pin is provided for fixation of a belt strap. 
         [0003]    To fix a belt strap on a belt reel, belt reels have a belt strap pin that is arranged in a receiving space of the reel body. At the end of the belt strap, a loop is provided, which is guided into the receiving space through a receiving gap. The belt strap pin is guided through this loop and fastened in the coil body so that the belt strap is securely held in the coil body. 
         [0004]    When the belt strap is not completely uncoiled from the belt reel, the tensile forces affecting the belt strap are partly transferred to the outer surface of the belt reel. When the belt strap is fully unwound, however, the load is fully transmitted via the belt strap pin so that the belt strap pin or its bearing has to be dimensioned correspondingly stable. For cost reasons, belt reels are frequently made of plastic, for instance of fiber-reinforced plastics. However, these belt reels are subject to the same strength requirements as conventional belt reels. Additionally, a simple assembly and disassembly is desired, for example to replace the belt reel. In belt reels provided with a torsion bar in the receiving space, the belt strap pin is capable of supporting itself on the torsion bar in order to reduce the load on the reel body. 
       SUMMARY OF THE INVENTION 
       [0005]    It is an object of the invention to provide a belt reel with a base body made of plastic that ensures a fastening of the belt strap pin within the receiving space independent of further components in the receiving space, and also enables a simple assembly or disassembly of the belt strap pin or the belt strap. 
         [0006]    To achieve this object, a belt reel for a safety belt in a vehicle is provided, including a base body made of plastic and having a receiving space in which a belt strap pin is provided to fixate the belt strap, wherein a first end of the belt strap pin is directly held on the base body of the belt reel and a second end of the belt strap pin is held in a separate receiving part that is fixed to the base body. 
         [0007]    According to the invention, two bearings are provided on the belt reel in which the belt strap pin can be inserted and which fixate the belt strap pin in the receiving space. Because one of these bearings is situated on a separate receiving part, the belt strap pin can be inserted with one end into the bearing that is directly provided on the base body, and subsequently the receiving part together with the second bearing can be pushed onto the second end of the belt strap pin and fixated on the base body. This enables a simple and fast fixation of the belt strap pin because the belt strap pin can simply be inserted into the receiving space and is fixated by the receiving part. Since both ends of the belt strap pin are securely fixated on the belt reel, a shifting of the belt strap pin is not possible. The belt reel may be reinforced in the area of these bearings so that these can safely absorb and transmit the occurring loads. The remaining areas of the belt reel may be dimensioned more lightweight. 
         [0008]    A first end side of the receiving space may for instance be closed, and the first end of the belt strap pin held in this end side. The receiving space may for example be configured cylindrical, wherein the cylinder axis corresponds to the rotation axis of the belt reel. This receiving space is open on one of the flanges so that the belt strap pin is inserted into the receiving space in axial direction. 
         [0009]    In this embodiment, an opening is provided at the second end side of the receiving space and the receiving part is fixated in this opening. This means that the opening and the receiving space are sealed by the receiving part, wherein the belt strap pin is securely held in axial direction. 
         [0010]    On the receiving part a bearing for the belt reel may also be provided. The further bearing is for example provided on the first end side of the base body. In this embodiment, the receiving part cannot be moved out of the opening in axial direction because the shifting of the receiving part out of the opening is prevented by a belt retractor frame or other components, in which the bearings are supported. As a result, a secure fixation of the receiving part on the base body of the belt reel and a secure fixation of the belt strap pin is ensured without further components or fastening devices. 
         [0011]    On the receiving element, a further mounting for components of a bell retractor, particularly a retractor spring can be provided. The receiving part can easily be exchanged so that a simple adaptation to specific retractor springs or other components of the belt retractor is possible. In such an embodiment, the receiving element is configured so that it cannot be rotated relative to the base body with regard to the rotation axis of the belt real, so that torques can be reliably transmitted between the receiving part and the base body. 
         [0012]    On the end sides of the base body, flanges can be provided, which in particular have toothings, in which for example a locking mechanism can engage. The ends of the belt strap pin can protrude into these flanges in longitudinal direction so that a direct load support from the belt strap pin to the flanges and from there to the belt retractor frame is accomplished. 
         [0013]    The receiving part can for example also extent into the receiving space and stabilize it. 
         [0014]    Preferably, the axis of the belt strap pin extends eccentrically to the axis of the base body. As a result, space is provided in the receiving space for an optional torsion bar or another force limiter, which has to be arranged centrically within the receiving space. Preferably, the axis of the belt strap pin is arranged on a side of the base body&#39;s axis, which faces away from the receiving gap. The belt strap is usually sewn as a loop, wherein the seam area is significantly more rigid than the remaining belt strap. The eccentric arrangement of the belt strap pin is preferably such that this more rigid seam area is situated within the belt reel so as to not impede the winding up of the belt strap to the belt reel. 
         [0015]    The base body has for example hollow spaces, which in particular are reinforced with longitudinal ribs and/or transverse ribs. This allows significantly saving material and with this reduce the weight of the belt reel while maintaining the same stability. The longitudinal ribs and/or transverse ribs can be arranged in areas exposed to particularly high stresses so that the belt reel has sufficient stability. 
         [0016]    The base body can for example have an outer surface, that is substantially closed in circumferential direction. 
         [0017]    In order to stabilize areas of the base body and the belt reel that are exposed to particularly high stresses, it is also possible to arrange inserts, in particular made of metal, within the base body, which provide higher strength than plastics. 
         [0018]    Preferably, the belt reel is produced by way of an injection molding process, in particular by a multi-component injection molding process. In such a multi-component injection molding process further components, for example inserts or components that for example provide a spring function, an elastic support for the belt reel or noise-insulated support, may be molded onto the belt reel in one piece. 
         [0019]    The belt strap pin preferably has a diameter between 7 and 10 mm. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]    Further advantages and features will become apparent from the following description in conjunction with the enclosed drawings. It is shown in: 
           [0021]      FIG. 1  a perspective view of a belt reel according to the invention, 
           [0022]      FIG. 2  a sectional view through a belt retractor with a belt reel according to the invention, 
           [0023]      FIG. 3  a sectional view through a belt retractor as shown in  FIG. 1 , and 
           [0024]      FIG. 4  a detailed view of the receiving part of the belt reel as shown in  FIG. 1 . 
       
    
    
     DESCRIPTION 
       [0025]      FIG. 1  shows a belt reel  10  for a belt retractor  12  as shown in  FIG. 2 . The belt retractor  12  is a conventional belt retractor with a frame  14 , bearings  16 ,  18  for the belt reel  10  as well as a locking mechanism  20  and a retractor mechanism for the belt reel  10  that is not shown in detail. 
         [0026]    The belt reel  12  has a base body  22  with a receiving gap  24 , through which a receiving space  26  within the base body  22  is accessible. The belt reel  10  also has a first flange  28 , which has connecting devices for the retractor mechanism as well as a second flange  32  with a toothing  33  into which the locking mechanism  20  can engages. 
         [0027]    Within the receiving space  26  a belt strap pin  34  is provided, to which a belt strap  36  of a safety belt may be fastened (see  FIG. 3 ). The end of the belt strap  38  is sewn into a loop  38  through which the belt strap pin  34  passes. Within the receiving space  26  bearings  40 ,  43  are provided on which the belt strap pin  34  is supported so as to be securely held within the receiving space  26  ( FIG. 2 ). 
         [0028]    As shown in  FIG. 2  the receiving space  26  is substantially configured cylindrical, wherein the central axis M of the receiving space  26  corresponds to the rotation axis D of the belt reel  10 . On a first end side  44 , the receiving space  26  is closed. On the second end side  46 , the receiving space  26  has an opening  48 . 
         [0029]    The first bearing  40  for the first end  52  of the belt strap pin  34  is provided on the first end side  44 . A receiving element  54  is inserted into the opening  48 , on which receiving element the second bearing  42  for the second end  56  of the belt strap pin  34  is located. 
         [0030]    In order to install the belt retractor  12 , the belt strap  36  is inserted with the loop  38  through the receiving gap  24  into the receiving space  26 . Subsequently, the belt strap pin  34  is pushed through the opening  48  into the receiving space  26  and through the loop  38  of the belt strap  36 , until the first end  52  of the belt strap pin  34  is inserted into the first bearing  40 . 
         [0031]    Then, the receiving element  54  is inserted into the opening  48 , wherein the second bearing  42  is placed onto the second end  56  of the belt strap pin  34 . As a result, the belt strap pin  34  is securely held between both bearings  40 ,  42 . 
         [0032]    As shown in  FIG. 2 , the first bearing  40  or respectively the first end side  44  is arranged within the first flange  28 . The receiving part  54  is arranged with the second support in the second flange  32 . As a consequence, loads can be transmitted directly from the belt strap pin  34  to the flanges  28 ,  34  and consequently to the frame  14  of the belt retractor  12 . 
         [0033]    As shown in  FIG. 1  and particularly in  FIG. 4 , the bearing of the second flange  32  is in this case arranged on the receiving element  54 . When the belt reel  10  is mounted in the belt retractor  12 , an axial shifting and thus a release of the belt strap pin&#39;s  34  fixation is not possible because the receiving element  54  abuts a bearing  16  of the belt retractor  12 . As a result, the belt strap pin  34  is securely fastened when the belt reel  10  is mounted in the belt retractor  12 . 
         [0034]    As shown in  FIG. 4 , the receiving element  54  and the second flange  32  are configured so that the receiving element  54  extends into the receiving space  26 , thereby providing a further stabilization of the receiving space  26  or the base body  22  of the belt reel  10 . 
         [0035]    In addition, the receiving element  54  and the second flange  32  provide an cooperating torque transmission profile, so that torques may be transmitted between receiving element  54  and belt reel  10 . Additional components can therefore engage on the receiving element  54  of the belt retractor  12 , for instance a spring retractor. 
         [0036]    The belt strap pin  34  may be arranged in any desired manner within the receiving space  26 . In the shown embodiment, the belt strap pin  34  is arranged eccentrically to the axis of the base body  22 . As a consequence, the seam area  60  of the belt strap  26  is held in the base body so that the seam area  60  does not protrude out of the receiving gap  24  and does not impede the winding up of the belt strap  36 . 
         [0037]    An eccentric support of the belt strap pin  34  also allows arrangement of further components in the receiving space, for example a torsion bar or another force limiter. 
         [0038]    For weight reasons, the base body is preferably made of plastic, wherein the base body  22 , in addition to the receiving space  26 , further includes hollow spaces  62 ,  64 , which are stiffened by longitudinal ribs or transverse ribs  66 . 
         [0039]    Additionally, inserts for example made of metal, may be arranged within the base body  22 , to reinforce areas that are exposed to particularly high stresses. The outer surface of the base body may, for example, be closed in circumferential direction, except for the receiving gap  24 . 
         [0040]    The belt reel  10  can for example be produced by way of an injection molding process, wherein a multi-component injection molding process allows molding-on further components. These components may, for example, provide a spring function or effect an elastic or noise-insulated support of the belt reel.