Abstract:
A reel device is assembled with a wire harness routed between a fixed member and a movable member. A casing has a first port to which a fixed first portion of the wire harness is fixed and lead out therefrom, and a second port from a movable second portion of the wire harness is lead out. A roller is rotatably provided in the casing. The roller includes a partition plate for partitioning inside of the casing a first accommodating space and a second accommodating space. A shaft member is formed on the partition plate so as to be located in the first accommodating space, on which the first portion of the wire harness is wound. A reel drum is formed on the partition plate so as to be located in the second accommodating space and having a belt member a first end of which is fixed thereon. The reel drum winds a predetermined length of the second portion of the wire harness thereon together with the belt member the second end of which is attached to the second portion of the wire harness. A notch is formed on an outer periphery of the partition plate, to which a third portion defining a boundary between the first and second portions of the wire harness is engaged. A reel spring is provided in the reel drum for urging the roller toward a direction for taking up the second portion of the wire harness into the casing.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a reel device for a wire harness which is assembled onto a wire harness for being routed between a fixed body and a movable member, and which is suitable for use for a wire harness which is routed between, for example, the vehicle body of a vehicle such as an automobile and a door which is openably mounted therein. 
     Various electric equipment such as a motor for a power window and a door-mounted speaker are generally assembled in a door for a vehicle such as an automobile, and a wire harness needs to be routed between the vehicle body and the door so as to electrically connect such electric equipment on the one hand, and a power source, a control unit, and various sensors located on the vehicle body side on the other hand. 
     FIG. 14 shows a related reel device for a flat-cable disclosed in Japanese Patent Publication No. 11-116145A. This reel device is comprised of a flat cable  72  having a distal end portion connected to a movable connector  70  and a proximal end portion connected to a fixed connector  71 ; a fixed shaft member  73  on which the fixed connector  71  is disposed; and a carrier  74  supported by the shaft member  73  and adapted to rotate around its outer periphery. The arrangement provided is such that the carrier  74  is drawn out in a direction opposite to the taking-up direction of the flat cable  72 , and the flat cable  72  is taken up onto an outer peripheral face of the shaft member  73  and an outer peripheral face of the carrier  74  in such a manner as to be oriented in mutually opposite directions as the carrier  74  is rotated. 
     In addition, FIGS. 15 and 16 show another related reel device for a wire harness disclosed in Japanese Patent Publication No. 63-176272A. In this reel device, a movable connector  81  is disposed at one end of a flat cable  80 , while a fixed connector  82  is disposed at the other end thereof. A lengthwise intermediate point of the flat cable  80  is passed through an opening  84  provided in a side face of a reel body  83 , and is fixed to the reel body  83  in the vicinity of the opening  84 . One half of the flat cable  80  extending from the intermediate point to the movable connector  81  is wound around the reel body  83 , and can be drawn out from a casing  85  against the spring force of a reel spring. The remaining half of the flat cable  80  is placed on the outer side of the reel body  83  and is positioned in such a manner as to be capable of being tightened around an extended shaft of the reel body  83 . Further, the fixed connector  82  is provided in such a manner as to be exposed on the outer side of the casing  85 . 
     The above-described former and latter related techniques have the following problems, respectively. 
     (1) Each of the related techniques is a reel device for a flat cable, and the apparatus is difficult to be assembled onto a wire harness composed of a plurality of electric wires (wires having circular cross sections) which are routed between a fixed member and a movable member. 
     (2) Each time the flat cable is drawn out from the casing or rewound into the casing depending on the movement of the movable member, a force is applied to the flat cable, and the stress to which the flat cable is subjected is large. Hence, there is a possibility of the flat cable becoming disconnected. 
     (3) Connectors to be connected to other wires need to be provided at opposite ends of the flat cable, and connectors are also required on the other wire sides. In addition, since the cost of the flat cable itself is high, the manufacturing cost increases. 
     (4) The operation of assembling the flat cable into the casing is troublesome. For example, with the above-described latter related technique, a troublesome operation is required in which the intermediate point of the flat cable  80  is passed through the opening  84  in the reel body  83 , and its one half is wound around the reel body  83 . 
     SUMMARY OF THE INVENTION 
     The invention has been devised in view of the above-described problems of the related arts, and its object is to provide a reel device which permits easy assembly onto an elongated wire harness at its arbitrary position, and which reduces stress on the electric wires and makes it possible to reduce the manufacturing cost. 
     In order to achieve the above object, according to the present invention, there is provided a reel device assembled with a wire harness routed between a fixed member and a movable member, comprising: 
     a casing having a first port to which a fixed first portion of the wire harness is fixed and lead out therefrom, and a movable second port from a second portion of the wire harness is lead out; 
     a roller rotatably provided in the casing, the roller including a partition plate for partitioning inside of the casing a first accommodating space and a second accommodating space; 
     a shaft member formed on the partition plate so as to be located in the first accommodating space, on which the first portion of the wire harness is wound; 
     a reel drum formed on the partition plate so as to be located in the second accommodating space and having a belt member a first end of which is fixed thereon, the reel drum for winding a predetermined length of the second portion of the wire harness thereon together with the belt member the second end of which is attached to the second portion of the wire harness; 
     a notch formed on an outer periphery of the partition plate, to which a third portion defining a boundary between the first and second portions of the wire harness is engaged; and 
     a reel spring provided in the reel drum for urging the roller toward a direction for taking up the second portion of the wire harness into the casing. 
     In accordance with the above-described arrangement, when the reel device is assembled onto the wire harness, the belt member is drawn out, the third portion of the wire harness is retained at the notch, and the movable second portion of the wire harness is fixed to the belt member. If the belt member is released, the roller rotates by the urging force of the reel spring, so that the second portion of the wire harness, together with the belt member, is automatically taken up onto the outer periphery of the reel drum. The fixed first portion of the wire harness is loosely wound around the shaft member, is fixed at the first port of the casing, and is led to the outside. Moreover, since the slack wire harness can be accommodated in the first accommodating space, the apparatus can be assembled onto the elongated wire harness at its arbitrary position. 
     When a tensile force is applied to the belt member, this force is transmitted to the roller through the belt member. In turn, the roller rotates against the urging force of the reel spring, so that the second portion of the wire harness, together with the belt member, is drawn out to the outside. Meanwhile, when the tensile force is canceled, the roller rotates in the taking-up direction by the urging force, and this rotation is transmitted to the second portion of the wire harness through the belt member, thereby taking up the second portion of the wire harness together with the belt member. Thus, since practically no force is applied to the wire harness during both the drawing out and taking up of the movable-side wire harness, the stress to which the electric wires of the wire harness are subjected is small. 
     In addition, since this device is directly assembled onto the wire harness which is routed between the fixed member and the movable member, the device does not require connectors and can be manufactured at low cost. 
     Preferably, a retainer for fixing the second portion of the wire harness to either the fixed member or the movable member is provided on the second end of the belt member. 
     In accordance with the above-described arrangement, the movable second portion of the wire harness can be easily fixed to either the fixed member or the movable member by means of the retainer. 
     Preferably, the casing including an upper casing body and a lower casing body for accommodating the roller therebetween. The roller is rotatably supported on a cylindrical shaft member projected from a bottom face of the lower casing body. 
     In accordance with the above-described arrangement, the roller can be assembled easily onto the lower casing body merely by rotatably fitting to the cylindrical shaft member of the lower casing body. Thus, the assembling operation can be performed simply. 
     Preferably, the reel spring is a torsion coil spring or a spiral spring, one end of which is fixed on an outer peripheral face of the cylindrical shaft member, and the other end of which is fixed on an inner peripheral face of the reel drum. The reel spring is compressed between the bottom face of the lower casing body and a lower face of the partition plate of the roller. 
     In accordance with the above-described arrangement, even if the casing vibrates, a reaction force is constantly applied to that spring, and the vibration is absorbed by the spring. Accordingly, it is possible to prevent the occurrence of abnormal noise attributable to the free play of the reel spring. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the accompanying drawings: 
     FIG. 1 is a perspective view illustrating a reel device in accordance with a first embodiment of the invention; 
     FIG. 2 is a perspective view illustrating the external appearance of the embodiment shown in FIG. 1; 
     FIG. 3 is an exploded perspective view of the embodiment shown in FIG. 1; 
     FIG. 4 is a vertical cross-sectional view of the embodiment shown in FIG. 1; 
     FIG. 5 is a plan view illustrating a portion where a wire harness is fixed to a casing of the embodiment shown in FIG. 1; 
     FIG. 6 is a perspective view illustrating a portion where the wire harness is fixed to a roller of the embodiment shown in FIG. 1; 
     FIGS. 7A to  7 C are explanatory diagrams illustrating the procedure of assembly onto the wire harness in the embodiment shown in FIG. 1; 
     FIGS. 8A to  8 C are diagrams explaining the operation of the embodiment shown in FIG.  1  and illustrate how the movable-side wire harness operates; 
     FIGS. 9A to  9 C are diagrams explaining the operation and illustrate how the fixed-side wire harness operates. 
     FIG. 10 is a partial cross-sectional view illustrating a reel device in accordance with a second embodiment of the invention; 
     FIG. 11 is a plan view of a reel spring shown in FIG. 10; 
     FIG. 12 is a front elevational view illustrating a reel spring in a reel spring according to a third embodiment of the invention; 
     FIG. 13 is a plan view of the reel spring shown in FIG. 12; 
     FIG. 14 is a horizontal cross-sectional view illustrating a first related reel device; 
     FIG. 15 is a perspective view illustrating a second related reel device; and 
     FIG. 16 is a plan view illustrating the interior of the second related reel device. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereafter, a description will be given of preferred embodiments of the reel device in accordance with the present invention. 
     FIGS. 1 to  4  show a reel device in accordance with a first embodiment of the invention, in which FIG. 1 is a perspective view illustrating an internal structure of the apparatus, FIG. 2 is a perspective view illustrating the external appearance of the apparatus, FIG. 3 is an exploded perspective view of the apparatus, and FIG. 4 is a vertical cross-sectional view of the apparatus. 
     The reel device is an apparatus for establishing electrical connection between a fixed member and a movable member, e.g. between the vehicle body of a vehicle such as an automobile and a door which is openably mounted therein, and the apparatus is assembled onto a wire harness which is routed between the fixed body and the movable member. For instance, this reel device is used in a front door, a back door, a sunroof, a luggage door (the door of a trunk room), or the like of a vehicle such as an automobile. As shown in FIGS. 1 to  4 , this reel device has a pair of upper and lower covers  1  and  2  which are combined to form a casing  3  in which two harness leading-out ports are formed, and a roller  4  which is rotatably provided in the casing  3 . 
     As shown in FIGS. 3 and 4, the lower cover  2  has a bottom wall  6  having a tubular supporting shaft  5  formed projectingly on a central portion thereof, as well as a pair of opposing side walls  7  and  8  disposed uprightly on peripheral edges of the bottom wall  6 . The supporting shaft is a hollow cylindrical portion whose upper and lower ends are open and which has a stepped portion  5   a  at its heightwise substantially intermediate portion, and a bolt insertion hole  9  is formed in its upper hollow cylindrical portion  5   c  having a smaller diameter than a lower hollow cylindrical portion  5   b . In addition, harness leading-out ports  10  and  11  are formed by opposite ends of the side walls  7  and  8  at positions substantially symmetrical about the axis of the supporting shaft  5 . Meanwhile, the upper cover  1  is a cover member for the lower cover  2  and has a circular bore  12  in its center, and projecting pieces  14  each having a locking hole  13  are formed at a plurality of (in this embodiment, six) positions in its peripheral edges. The upper and lower covers  1  and  2  are joined together as a plurality of (altogether six) engagement projections  15  which are respectively provided projectingly on the side walls  7  and  8  of the lower cover  2  are respectively fitted in the locking holes  13  in the projecting pieces  14 . 
     As shown in FIGS. 3 and 4, the roller  4  has a partition plate  18  for partitioning the interior of the casing  3  into a first accommodating space  16  and a second accommodating space  17 ; a supporting shaft  19  and a hollow cylindrical reel drum  20  which are respectively provided on the upper side and the lower side of the partition plate  18  at its central portion; and a bottom plate  29  which extends from a lower end of the reel drum  20  in parallel with the partition plate  18  and comes into face contact with the bottom wall  6  of the lower cover  2 . The roller  4  is rotatably provided in the casing  3 . The supporting shaft  19  has a through hole  21  through which the aforementioned upper hollow cylindrical portion  5   c  is inserted, a circular recessed portion  22  which is rotatably fitted to the stepped portion  5   a  of the supporting shaft is formed in a lower portion of the supporting shaft  19 . Further, a circular recessed portion  25  for accommodating a head of a bolt  23  and a washer  24  is formed in an upper portion of the supporting shaft  19 . In a state in which the circular recessed portion  22  of the supporting shaft  19  is fitted to the stepped portion  5   a  of the supporting shaft, the upper hollow cylindrical portion  5   c  of the supporting shaft is fastened by a nut  26  and the bolt  23  inserted in the bolt insertion hole  9  by means of the washer  24 , whereby the supporting shaft  19  of the roller  4  is set free between the stepped portion  5   a  and the washer  24  and is rotatably held on the lower hollow cylindrical portion  5   b  of the supporting shaft. As the bottom plate  29  of the roller  4  is brought into face contact with the bottom wall  6  of the lower cover  2  with the roller  4  thus assembled rotatably inside the lower cover  2 , the roller  4  is able to rotate smoothly inside the casing  3 . 
     A circular notched portion  28  for passing a wire harness  27  therethrough is provided in an outer periphery of the partition plate  18 . The wire harness  27  is a continuous elongated member composed of a plurality of electric wires (wires having circular cross sections), and a bent portion  30  formed by bending a portion of the wire harness  27  is retained in the notched portion  28  (see FIGS.  1  and  4 ). 
     Of the wire harness  27 , a movable-side wire harness  27   a  extending from the notched portion  28  to the interior of the second accommodating space  17  has one end  31  a fixed to a belt member  31  fixed to an outer periphery of the reel drum  20 , is wound, together with the belt member  31 , around an outer periphery of the reel drum  20  by a predetermined length, and extends to the outside from one harness leading-out port  10  of the casing  3 . The movable-side wire harness  27   a  and the belt member  31  are fixed together by taping  32  at one or a plurality of locations (in this embodiment, three locations as shown in FIG.  7 B). 
     Meanwhile, of the wire harness  27 , a fixed-side wire harness  27   b  which extends from the notched portion  28  in the roller  4  to the interior of the first accommodating space  16  is loosely wound around the supporting shaft  19 , is accommodated in the first accommodating space  16 , is fixed at the other harness leading-out port  11  of the casing  3 , and extends to the outside from the harness leading-out port  11 . As shown in FIG. 5, the fixed-side wire harness  27   b  is fixed to the other wire harness leading-out port  11  by means of taping  33 , a band, or the like. 
     In addition, a reel spring (power spring)  34  for urging the roller  4  in the direction of rewinding the movable-side wire harness  27   a  into the casing  3  is accommodated inside the reel drum  20  of the roller  4 . Namely, the reel spring  34  is accommodated in the reel drum  20  such that when a tensile force is applied to the belt member  31 , and this force is transmitted to the roller  4  through the belt member  31  so as to rotate the roller  4 , the diameter of the reel spring  34  is reduced, and when the tensile force is canceled, the reel spring  34  urges the roller  4  so as to rotate the roller  4  in the taking-up direction by means of its restoring force from the state of the reduced diameter. One end  34   a  of the reel spring  34  is fixed to the lower hollow cylindrical portion  5   b  of the supporting shaft, and its other end  34   b  is fixed to the reel drum  20 . 
     Further, the belt member  31  is formed of flexible cloth, thin metal plate, or the like. A retainer  35  is fixed to an end portion (other end)  31   b  of that portion of the belt member  31  which extends to the outside from one harness leading-out port  10 . This retainer  35  is made up of a main body  35   a  fixed to the end portion  31   b  and a clamp  35   b  provided projectingly on the main body  35   a . The movable-side wire harness  27   a  is fixed as the clamp  35   b  is engaged in a retaining hole or a groove in a harness fixing portion (e.g., an inner panel of the door) of either the fixed member or the movable member. Instead of the clamp  35   b , a retaining portion such as a retaining hole may be provided in the main body  35   a  of the retainer  35 . 
     Next, referring to FIGS. 7A to  7 C, a description will be given of the procedure of assembling the reel device having the above-described arrangement onto the wire harness. Here, a description will be given of a case in which the reel device is assembled onto the wire harness which is routed between the vehicle body (fixed member) and a door (movable member) of a vehicle such as an automobile. 
     First, the roller  4  in which the reel spring  34  is accommodated in the reel drum  20  thereof is rotatably assembled onto the lower cover  2  by means of the bolt  23  and the nut  267  as shown in FIG.  4 . In this state, as shown in FIG. 7A, the belt member  31  is drawn out from the harness leading-out port  10  until the notched portion  28  in the partition plate  18  is brought to a position facing one harness leading-out port  10  in the lower cover  2  (in the casing  3 ), and the main body  35   a  of the retainer  35  is fixed by being engaged in a retaining groove in a jig  36 . 
     Next, as shown in FIG. 7B, the bent portion  30  formed by bending a portion of the wire harness  27  is retained in the notched portion  28  in the partition plate  18  (see FIG.  6 ), and the movable-side wire harness  27   a  extending from the notched portion  28  toward the second accommodating space  17  side is fixed to the belt member  31  at a plurality of positions by the taping  32 . 
     Next, if the fixation of the belt member  31  is canceled by removing the main body  35   a  from the jig  36 , the roller  4  rotates clockwise from the position shown in FIG. 7B by the urging force of the reel spring  34 . Hence, the movable-side wire harness  27   a , together with the belt member  31 , is drawn into the lower cover  2 , and is automatically taken up onto the outer periphery of the reel drum  20  by a predetermined length (see FIG.  7 C). 
     Next, the fixed-side wire harness  27   b  extending from the notched portion toward the first accommodating space  16  side is loosely wound around the supporting shaft  19  (is wound, for instance, clockwise from the notched portion  28 ) by an appropriate length corresponding to the length of the movable-side wire harness  27   a  wound around the reel drum  20  (see FIG.  7 C). Subsequently, the fixed-side wire harness  27   b  is fixed to the other harness leading-out port  11  of the lower cover  2  by the taping  33 , a band, or the like (see FIGS.  5  and  7 C), and is led from the harness leading-out port  11  to the outside. 
     Subsequently, the upper cover  1  is fixed to the lower cover  2 , as shown in FIGS. 2 and 4. 
     Finally, the clamp  35   b  of the retainer  35  is fixed to the harness fixing portion of either the vehicle body or the door, and the casing  3  is fixed to the other harness fixing portion by an unillustrated retainer, thereby completing the assembly onto the wire harness  27 . 
     Next, referring to FIGS. 8A to  8 C and  9 A to  9 C, a description will be given of the operation of the above-described reel device. FIGS. 8A to  8 C are diagrams explaining the operation and illustrate how the movable-side wire harness operates. FIGS. 9A to  9 C are diagrams explaining the operation and illustrate how the fixed-side wire harness operates. 
     First, as shown in FIG. 8A, if an openable member such as a door is opened, a tensile force is applied to the retainer  35 , and this tensile force is transmitted to the roller  4  through the belt member  31 , so that the roller  4  rotates counterclockwise in the drawing against the urging force of the reel spring  34 . Due to this rotation, the movable-side wire harness  27   a , together with the belt member  31 , is drawn out from the harness leading-out port  10  (see FIG.  8 B). 
     Subsequently, when the openable member is closed and the tensile force is canceled, the roller  4  is rotated clockwise from the position shown in FIG. 8C by the urging force of the reel spring  34 . Since the belt member  31  is drawn into the casing  3  by this rotation, the movable-side wire harness  27   a , together with the belt member  31 , is taken up onto the outer periphery of the reel drum  20 , and is returned to the state shown in FIG.  8 A. 
     Meanwhile, as shown in FIG. 9A, the fixed-side wire harness  27   b  is loosely wound around the supporting shaft  19  of the roller  4  in the state in which the movable-side wire harness  27   a  has been retracted into the casing  3  as shown in FIG.  8 A. In this state, if the roller  4  rotates counterclockwise in the drawing, the fixed-side wire harness  27   b  moves in the direction of being loosely wound around the supporting shaft  19  (see FIGS.  9 B and  9 C). 
     Subsequently, when the openable member is closed and the roller  4  is rotated clockwise from the position shown in FIG. 9C by the urging force of the reel spring  34 , the fixed-side wire harness  27   b  moves in a loosening direction, and returns to the state shown in FIG.  9 A. 
     In accordance with the reel device in the above-described embodiment, the assembling operation can be performed easily, as described above. Moreover, the slack wire harness can be accommodated in the first accommodating space  16 . Accordingly, the reel device can be assembled onto the elongated wire harness at its arbitrary position. 
     Further, since practically no force is applied to the wire harness  27  during both the drawing out and taking up of the movable-side wire harness  27   a , the stress to which the electric wires of the wire harness  7  are subjected is small. 
     In addition, since this device is directly assembled onto the wire harness which is routed between the fixed member and the movable member, the device does not require connectors and can be manufactured at low cost. 
     In addition, in accordance with the above-described embodiment, since the retainer  35  is provided on the end portion  31   b  of the belt member  31 , the movable-side wire harness  27   a  can be easily fixed to the harness fixing portion of either the fixed member or the movable member. 
     Further, in accordance with the above-described embodiment, in the state in which the circular recessed portion  22  of the supporting shaft  19  of the roller  4  is fitted to the stepped portion  5   a  of the supporting shaft, the upper hollow cylindrical portion  5   c  of the supporting shaft is merely fastened by the nut  26  and the bolt  23  inserted in the bolt insertion hole  9  by means of the washer  24 . As a result, the supporting shaft  19  is set free between the stepped portion  5   a  and the washer  24  and is rotatably held on the lower hollow cylindrical portion  5   b  of the supporting shaft. Accordingly, the roller  4  can be easily assembled onto the lower cover  2 . 
     FIGS. 10 and 11 show a reel device in accordance with a second embodiment of the above-described embodiment. Although in the above-described embodiment the power spring is used as the reel spring  34 , a torsion coil spring  37  shown in FIG. 11 is used as the reel spring  34  in this embodiment. One end of the torsion coil spring  37  is fixed to an outer periphery of the supporting shaft, and the other end thereof is fixed to an inner periphery of the reel drum  20 . Further, the torsion coil spring  37  is compressed between the bottom wall  6  of the lower cover  2  and the partition plate  18  of the roller  4 . By virtue of this arrangement, even if the casing  3  vibrates, a reaction force is constantly applied to the torsion coil spring  37 , and the vibration is absorbed by the spring  37 . Accordingly, it is possible to prevent the occurrence of abnormal noise attributable to the free play of the torsion coil spring (reel spring)  37 . 
     Furthermore, instead of the torsion coil spring  37 , a spiral spring  38  such as the one shown in FIGS. 12 and 13 may be used as the reel spring  34  by being compressed in the same way as in the second embodiment. In this case as well, it is possible to prevent the occurrence of the abnormal noise. 
     Although the present invention has been shown and described with reference to specific preferred embodiments, various changes and modifications will be apparent to those skilled in the art from the teachings herein. Such changes and modifications as are obvious are deemed to come within the spirit, scope and contemplation of the invention as defined in the appended claims.