Abstract:
A cable reel for installation on the steering apparatus of a vehicle is disclosed. The cable reel includes a stationary member, a rotatable member, a reverse member and a flat cable. The reverse member has a plurality of reverse portions integral with an annular member, the reverse portions being disposed at regular intervals in a circumferential direction around the annular member. The reverse portions may be reverse rings formed by bending and looping arms connected to the annular member. Alternatively the reverse portions may be vacuum-moulded projections. The cable reel winds the flat cable, accommodated by reversal of winding of the flat cable by the reverse member.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The present invention relates to cable reels of reverse type to be installed on a steering apparatus of a vehicle, and to methods of their formation. More particularly, the present invention relates to the improvement of a reverse ring for reversing a flat cable accommodated in an annular hollow space formed by a movable member and a stationary member. 
     2. Description of Related Art 
     A cable reel of reverse type to be installed on the steering apparatus of a vehicle, as shown in FIGS. 8A and 8B, has been proposed. In the cable reel of FIGS. 8A and 8B, a stationary member  19  serving as an outer cylinder is fixed to a steering column (not shown), and a movable member  12  serving as an inner cylinder is fixed to a steering wheel (not shown). The stationary member  19  and the movable member  12  are connected so as to be rotatable relative to each other. An annular rotary ring  17  made of synthetic resin is freely rotatably accommodated in the annular hollow space  18  formed by the stationary member  19  and the movable member  12 . Reverse rings  15  and  16  made of synthetic resin are locked to the rotary ring  17 . 
     In the annular hollow space  18 , flat cables  13  and  14  each having one end connected to the movable member  12  are wound in a space C 5  disposed between the movable member  12  and the reverse rings  15  and  16  and pass through two reverse gaps C 6  disposed between the reverse rings  15  and  16 . Then the flat cables  13  and  14  are wound in the opposite direction in a space C 4  disposed between the stationary member  19  and the reverse rings  15  and  16 . The other end of each of the flat cables  13  and  14  is connected to the stationary member  19 . 
     In this cable reel, when the steering handle or steering wheel is rotated in one direction, the flat cables  13  and  14  pass through the reverse gaps C 6  of the reverse rings  15  and  16  by sliding around the U-shape bends at the ends of the reverse rings  15  and  16 . In this way, the flat cables  13  and  14  move to the inner side of the reverse ring and are wound on the peripheral surface of the movable member  12 . On the other hand, when the steering handle or steering wheel is rotated in the opposite direction, the rewound flat cables  13  and  14  pass through the reverse gaps C 6  while they are moving back around the U-shaped bends. The flat cables  13  and  14  move to the outer side of the reverse rings  15  and  16  and are wound on the inner peripheral surface of the stationary member  19 . 
     In the cable reel described above, the reverse rings  15  and  16  are required to reverse the direction of winding of the flat cables  13  and  14 . To prevent vibrations of the reverse rings  15  and  16  in the annular hollow space  18 , the reverse rings  15  and  16  are locked to the rotary ring  17 . That is, to construct the member for reversing the flat cable, three parts are required. These are the two reverse rings  15  and  16  and one rotary ring  17 . 
     With an increase of the number of flat cables in such a cable reel, it is necessary to increase the number of reverse rings. This leads to an increase in the number of component parts and makes the manufacturing cost high. 
     The reverse rings  15  and  16  are fixed to the rotary ring  17  and thus they are incapable of moving in directions other than the rotary direction. Further, because the reverse rings  15  and  16  are not flexible, there is no change in the width of the space C 4  between the stationary member  18  and each of the reverse rings  15  and  16  and that of the space C 5  between the movable member  12  and each of the reverse rings  15  and  16 . 
     Accordingly, with an increase in the number of flat cables which pass through each space C 5  and C 6  due to the rotation of the movable member  12 , the width of each space is set, for example, during manufacture by adding an allowance thereto, i.e. each space is made wider if the cable reel carries a larger number of bundles of flat cables. This has the defect that the flat cables  13  and  14  may move freely or loosely in a wider portion of the passage when they are moved in each passage by the rotation of the movable member  12 . As a result, the flat cables  13  and  14  generate vibrations and abnormal sounds. 
     SUMMARY OF THE INVENTION 
     The present invention seeks to reduce or avoid the above-described problem. Accordingly, it is an object of the present invention to reduce the number of component parts in a cable reel of reverse type. A further object is to reduce or prevent generation of vibrations and/or abnormal sounds when a movable member rotates, by improving members for reversing a flat cable which is accommodated in an annular hollow space of a cable reel of reverse type. 
     Accordingly, the present invention provides a cable reel that includes: 
     a stationary member; 
     a rotatable member located with respect to the stationary member so as to define an annular hollow space between the rotatable and stationary members; 
     a reverse member accommodated in the annular hollow space, the reverse member including a plurality of reverse portions and an annular member, the reverse member being formed in one piece from; and 
     a flat cable accommodated in the annular hollow space, the flat cable having respective spaced portions fixed with respect to the stationary member and with respect to the rotatable member and an intermediate portion between the spaced portions which is wound on one of the reverse portions. 
     The reverse member may be made from a resiliently flexible sheet. 
     Preferably, the reverse portions are radially expansible loops formed so as to press part of the intermediate portion of the flat cable against the stationary member. Typically, each reverse portion is formed by looping an arm projecting from the annular member. Each arm may have a fixed end, fixed to the annular member, and a free end, the free end being slidably movable with respect to the fixed end. Alternatively, each arm may have a fixed end, fixed to the annular member, and a free end., the free end being engageable with the fixed end in order to retain the loop. In that case, the free end of the arm may be engageable with or lockable to the fixed end of the arm via a slot. 
     The annular member may be disposed centrally of circumferential arm projections which are bent and looped to form the reverse portions. 
     Preferably, the arm projections are L-shaped. 
     Each L-shaped arm projection may include a short transverse portion and a long longitudinal portion, the transverse portion connecting the longitudinal portion to the annular member. The slot may be formed on the longitudinal portion, near the fixed end of the arm. 
     Preferably, to form one of the reverse portions, the transverse portion is bent perpendicularly to the central annular member and the longitudinal portion is looped to form one of the reverse portions. The part of the flat cable wound on each reverse portion may be sandwiched between the outer surface of each reverse ring and the outer wall of the annular hollow portion and, optionally, between the adjacent reverse rings. Thus, when the flat cable moves with the rotation of the movable member, it can be difficult for the flat cable to move freely. This can assist in the suppression of the generation of vibrations and abnormal sounds. 
     Typically, the central annular member serves as a rotary ring and is disposed on a bottom surface of the annular hollow space. A gap between an inner peripheral surface of each reverse portion and a peripheral surface of the movable member may be identified as an inner peripheral passage for each flat cable to be fixed with respect to the movable member. A gap between the reverse portions adjacent to each other circumferentially may be identified as a reversing passage for each flat cable. A gap between a peripheral surface of each reverse portion and an inner peripheral surface of the stationary member may be identified as an outer peripheral passage for each flat cable. 
     In use, the rotary ring rotates with the rotation of each reverse ring because the rotary ring is integral with the reverse rings. Thus the rotary ring holds the position of the reverse rings, thus holding the reverse rings in the annular hollow space, with the reverse rings spaced at equal intervals. 
     In various exemplary embodiments. the reverse member is freely rotatable within the cable reel. That is, the reverse member is not fixed with respect to the rotary member or fixed member. Rotation of the reverse member typically occurs due to tension in the flat cables during winding of the flat cables into the inner peripheral passage. Rotation of the reverse member in the other direction may occur since the flat cables are preferably rigid enough to be capable of pushing the reverse portions during unwinding of the flat cables from the inner peripheral passage. 
     When the flat cable is wound tightly, the number of turns of the flat cable usually increases. In that case, it may be necessary to increase the width of the inner peripheral passage to accommodate the flat cable. However, in the case where each reverse portion is flexible, the width of the inner peripheral passage is widened according to the number of turns of the flat cable. In this way, it is possible to ensure smooth operation of tight winding of the flat cable. 
     The flexible sheet is preferably an insulating plastics material sheet. By using an insulating plastics material sheet, it is possible to manufacture a reverse member light in weight and at a low cost which is capable of securely insulating the flat cables in contact with the reverse ring. 
     Bending of the insulating plastics material sheet may be facilitated by making a bending portion thin. Preferably, the bending applied to the plastics material sheet is not a fully permanent deformation. However, the bending may leave the plastics material with a partial permanent deformation. 
     It is preferable to provide four reverse portions in the annular hollow space. 
     Of course, when four reverse portions are disposed in the annular hollow space, they can be used in any case where, for example, one, two, three or four flat cables are used. 
     When four reverse portions are disposed in the annular hollow portion, it is preferable that each of the four reverse portions (or rings) contacts the flat cable over a sufficient area to ensure that when the movable member rotates, the flat cable has a stable locus. 
     The number of the reverse portions is not limited to four but one, two or three reverse rings, or more than four reverse rings, may be used. 
     In another exemplary embodiment, the present invention provides a cable reel including: 
     a stationary member; 
     a rotatable member located with respect to the stationary member so as to define an annular hollow space between the rotatable and stationary members; 
     a reverse member accommodated in the annular hollow space, the reverse member being formed in one piece from a flexible sheet and including a plurality of reverse portions and an annular member, the annular member being disposed centrally of the reverse portions, each reverse portion being formed by bending and looping an L-shaped arm projection which is disposed at a circumference of said annular member; and 
     a flat cable accommodated in the annular hollow space, the flat cable having respective spaced portions fixed with respect to the stationary member and with respect to the rotatable member and an intermediate portion between the spaced portions which is wound on one of the reverse portions. 
     In another aspect, the present invention provides a method of forming a cable reel including the formation of a reverse member, wherein the reverse member has a plurality of reverse portions and a central annular member, the reverse portions being disposed at regular intervals in a circumferential direction around the central annular member, the reverse member being formed in one piece from a flexible sheet, the method including the step of bending and looping arm projections to form the plurality of reverse portions. 
     In another exemplary embodiment, the sheet is an annular sheet and the reverse portions are projections from a surface of the central annular member, the projections being formed by moulding of the annular sheet. 
     Preferably, the moulding operation gives reverse portions of a kidney shape. Preferably, the moulding is vacuum moulding. The reverse portions may be radially resiliently flexible. 
     Again, preferably the sheet is an insulating plastics material sheet. 
     As mentioned above, the reverse member including a plurality of the reverse portions may be formed in one piece by vacuum moulding of an annular sheet. Thus, the reverse member, which is accommodated in the annular hollow space, may be a single component. In this way, the number of component parts may be reduced. 
     The number of the flat cable-reversing portions required in the cable reel increases with the number of flat cables. However, since a plurality of reverse portions may be formed from one flexible sheet, it is possible to form the required number of reverse portions as a single reverse member component. Therefore, it is possible to reduce the number of component parts in the cable reel. 
     The formation of the reverse portions may be completed at the time of vacuum moulding. Assembly of the cable reel may be facilitated since the reverse portions are formed on the reverse member prior to assembly, so that it is only necessary simply to insert the reverse member into the annular hollow portion. 
     In an exemplary embodiment, the present invention provides a cable reel including: 
     a stationary member; 
     a rotatable member located with respect to the stationary member so as to define an annular hollow space between the rotatable and stationary members; 
     a reverse member accommodated in the annular hollow space, the reverse member being formed by vacuum moulding from an annular sheet to give an annular member with moulded projections from a surface of the annular member, the projections being disposed at regular intervals in a circumferential direction around the annular member, each moulded projection being a reverse portion; and 
     a flat cable accommodated in the annular hollow space, the flat cable having respective spaced portions fixed with respect to the stationary member and with respect to the rotatable member and an intermediate portion between the spaced portions which is wound on one of the reverse portions. 
     In a further aspect, the present invention provides a method of forming a cable reel including the formation of a reverse member, wherein the reverse member has a plurality of reverse portions, and an annular member, the reverse portions being disposed in a circumferential direction around said annular member. 
     The reverse member is formed in one piece by moulding of an annular sheet to give the reverse portions which project from a surface of the annular member. 
     In another aspect, the present invention provides a vehicle having a steering assembly including a cable reel according to any one of the above aspects. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Embodiments of the invention will now be described by way of non-limitative example with reference to the drawings, in which: 
     FIG. 1 is an exploded perspective view of component parts of a cable reel which is a first embodiment of the present invention; 
     FIGS. 2A,  2 B and  2 C show a process of forming a reverse member of the cable reel of the first embodiment, in which FIG. 2A is a view showing a punched sheet to form the reverse member and FIGS. 2B and 2C are perspective views each showing a bending process; 
     FIG. 3 is a vertical sectional view of the cable reel of the first embodiment; 
     FIG. 4 is a horizontal sectional view of the cable reel of the first embodiment; 
     FIG. 5 is a perspective view of the cable reel of the first embodiment when the cable reel is viewed from above; 
     FIGS. 6A,  6 B and  6 C show a process of forming a reverse member of a cable reel of a second embodiment of the invention, in which FIG. 6A is a view of a punched sheet to form the reverse member and FIGS. 6B and 6C are perspective views each showing a bending process; 
     FIGS. 7A and 7B show a reverse member of a cable reel of a third embodiment of the invention, in which FIG. 7A is a perspective view in which the reverse member is viewed from above, and FIG. 7B is a perspective view in which the reverse member is viewed from below; and 
     FIG. 8A is a horizontal sectional view of a known cable reel, and FIG. 8B is a perspective view showing a flat cable-reversing member of the known cable reel of FIG.  8 A. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     A cable reel  1  of the present invention is described below with reference to FIGS. 1 to  5 . A rotor  3  (rotatable or movable member) serving as an inner cylinder is relatively rotatably connected to a base case (stationary member)  7  serving as an outer cylinder. The base case  7  is fixed to a steering column (not shown) and has a peripheral wall  7   a  projecting from the periphery of an annular bottom wall  7   b . The rotor  3  is fixed to a steering wheel (not shown) and has a closed portion  3   d  projecting from the periphery of one end surface of a cylindrical portion  3   a.    
     A reverse member  6  having four reverse rings  6   a  continuous with the periphery of a rotary ring  6   b  is accommodated in an annular hollow space  8  between the base case  7  and the rotor  3  in such a way that the rotary ring  6   b  is freely rotatable with respect to the inner and outer walls of the annular hollow space  8  (see FIGS.  3  and  4 ). The annular hollow space  8  accommodates flat wiring cables  4  and  5  each having a first end connected to connector portions  3   b  and  3   c , respectively, of the rotor  3 , with the flat cables  4  and  5  wound on the reverse rings  6   a  respectively. A connector accommodation portion  7   c  (see FIG. 4) fixed to the base case  7  accommodates connectors  4   a  and  5   a  connected to the other end of the flat cables  4  and  5 , respectively. 
     The flat wiring cables  4  and  5  are provided for electrical connection of electrical components housed, e.g. in the steering wheel. Examples of such components are electrical sensors and actuators associated with an airbag located in the steering wheel, which must be electrically connected with other parts of the vehicle, e.g. the battery, to form operable electrical circuits. The cables  4  and  5  may extend further from the stationary member than shown in the drawings. For example, the flat cables may extend away from the steering assembly. 
     The rotor  3  has a top cover  9 , and a locking member  2  (FIGS. 1 and 3) fixes the rotor  3  to a steering shaft (not shown). 
     The reverse member  6  is formed in a flat shape from a resiliently flexible electrically insulating plastics material sheet, and is bent into the required configuration. The thickness of this sheet is preferably in the range of from about 0.1 to about 1.0 mm and more preferably from about 0.4 to about 0.6 mm to allow the reverse member  6  to be suitably flexible. Any suitable materials can be used to form the sheet so long as they are flexible and resilient (preferably with electrically insulating properties). A polypropylene sheet is one example of a preferable material because it is lightweight and inexpensive. 
     As shown in FIG. 2A, the insulating sheet is punched into a configuration having the annular rotary ring  6   b  (central annular portion) and four inverted L-shaped arms  6   c  projecting from the periphery of the rotary ring  6   b  at regular intervals in its circumferential direction. Each of the L-shaped arms  6   c  has a short transverse portion  6   c - 1  continuous with the rotary ring  6   b  and a long longitudinal portion  6   c - 2  continuous with the transverse portion  6   c - 1  and perpendicular to the transverse portion  6   c - 1 . 
     The sheet punched in the configuration as shown in FIG. 2A is then bent so that each arm  6   c  is bent upwardly perpendicularly at the transverse portion  6   c - 1 , as shown in FIG.  2 B. Each arm  6   c  is curved to a closed loop in such a way that the surface of the longitudinal portion  6   c - 2  confronting the center of the rotary ring  6   b  is disposed at the outer side of the rotary ring. In this manner, four upstanding reverse rings  6   a  are formed, as shown in FIG.  2 C. In the first embodiment, the free end of the longitudinal portion  6   c - 2  is in excess in length and is not fixed but overlaps the near end of the reverse ring  6   a  when accommodated in the annular hollow space  8  to keep the reverse ring  6   a  as a closed loop of kidney shape. 
     As shown in FIGS. 3 and 4, the reverse member  6  obtained by bending the flat sheet is accommodated in the annular hollow space  8 . The gap between the upper surface of the rotary ring  6   b , namely, the peripheral surface of the rotor  3  and the inner peripheral surface of each reverse ring  6   a  provides an inner peripheral passage C 2  for the flat cables  4  and  5 . The gaps (four gaps in total) between the reverse rings  6   a  adjacent to each other circumferentially provide reverse gaps or portions C 3  for the flat cables. The gap between the inner peripheral surface of the base case  7  and the peripheral surface of each reverse ring  6   a  provides a peripheral outer passage C 1  for the flat cables. 
     More specifically, with one end of the flat cables  4  and  5  connected, respectively, to the connector portions  3   b  and  3   c  of the rotor  3 , the flat cables  4  and may be wound counterclockwise in the inner peripheral passage C 2 . Two of the reverse portions C 3  are selected as passages. The winding direction of the flat cables  4  and  5  are reversed in the selected reverse portions C 3 , and the flat cables  4  and  5  are wound clockwise in the peripheral passage C 1 . The connector accommodation portion  7   c  accommodates the connectors  4   a  and  5   a  connected to the other end of the flat cables  4  and  5 , respectively. 
     Further, because the reverse member  6  has four reverse rings  6   a , the reverse member  6  can be used in any of the cases where the required number of the flat cables is one, two, three or four. Thus, it is not necessary to provide the reverse member in accordance with the number of the flat cables. That is, it is possible to reduce the number of parts. 
     The rotating operation of the cable reel  1  of the first embodiment will be described below. 
     When the rotor  3  rotates in unison with the rotation of the steering wheel (not shown), the flat cables  4  and  5  connected to the rotor  3  are operated in unison with the rotation of the rotor  3 . 
     When the rotor  3  is rotated counterclockwise as seen in FIG. 4, a portion of each of the flat cables  4  and  5  present in the inner peripheral passage C 2  reverses its winding direction via the reverse portion C 3  and moves to the outer peripheral passage C 1 . Thus, most of the length of each of the flat cables  4  and  5  may be wound to a limit point in the outer peripheral passage C 1 . 
     On the other hand, when the rotor  3  is rotated in the reverse direction, namely clockwise, most of the length of the flat cables  4  and  5  is wound in the inner peripheral passage C 2  to a limit point. 
     Because the reverse rings  6   a  are made of a resilient plastics sheet, they have a restoring force urging them to a flat configuration. That is, the reverse rings  6   a  in the annular hollow space  8  tend to expand radially so as always to minimize the width of each of the outer peripheral passage C 1  and the inner peripheral passage C 2 . 
     Therefore, when the rotor  3  rotates, the flat cables  4  and  5  are pressed against the peripheral surface of the reverse rings  6   a . Thus, the flat cables  4  and  5  are prevented from moving freely in the widthwise (radial) direction of each passage. Therefore, generation of vibrations or abnormal sounds can be suppressed. 
     The free end of each longitudinal portion  6   c - 2  is not fixed to the reverse ring  6   a , but overlaps a portion of the reversing  6   a . Thus, the diameter (radial dimension) of the reverse ring  6   a  can be flexibly enlarged or reduced with the reciprocation of the flat cables  4  and  5  in the peripheral passage C 1  and the inner peripheral passage C 2  caused by the rotation of the rotor  3 . 
     In the first embodiment, although the cable reel  1  has two flat cables, the flat cables  4  and  5  can be pressed against the reverse rings  6   a , with the flat cables  4  and  5  in contact with the reverse rings  6   a  over a wide area, by providing the cable reel with four reverse rings  6   a . Therefore, it is easy to stabilize the rotary locus of the flat cables  4  and  5  and achieve a smooth rotary motion. 
     The cable reel of a second exemplary embodiment, shown in FIG. 6, is similar to that of the first embodiment except for the construction of the reverse member  6 ′ of the second embodiment. Other parts will not be described again. 
     The reverse member  6 ′ of the second embodiment is different from the reverse member  6  of the first embodiment in that the extremity of the arm  6   c ′ which constitutes each reverse ring  6   a ′ of the second embodiment is locked at a locking portion. 
     More specifically, as shown in FIG. 6A, the insulating plastics material sheet is punched to give a shape having a rotary ring  6   b ′ and four L-shaped arms  6   c ′ projecting from the periphery of the rotary ring  6   b ′ at regular intervals in its circumferential direction. Each of the arms  6   c ′ has a short transverse portion  6   c - 1 ′ continuous with the rotary ring  6   b ′, a long longitudinal portion  6   c - 2 ′ continuous with the transverse portion  6   c - 1 ′ and perpendicular thereto, and a locking slot  6   c - 3 ′ in the form of a notch on a portion of the longitudinal portion  6   c - 2 ′ at the side of the transverse portion  6   c - 1 ′. The slot  6   c - 3 ′ is preferably perpendicular to the longitudinal direction of the longitudinal portion  6   c - 2 ′. 
     As shown in FIG. 6B, each arm  6   c ′ is bent upward at the transverse portion  6   c - 1 ′ lobe perpendicular to the rotary ring  6   b ′. Then each arm  6   c ′ is curved cylindrically in such a way that the surface of each longitudinal portion  6   c - 2 ′ facing the center of the rotary ring  6   b ′ is the outer surface of the arm  6   c ′. Thereafter, as shown in FIG. 6C, the extremity of the longitudinal portion  6   c - 2 ′ is inserted into the slot  6   c - 3 ′ and thus locked thereto. Thus it is easy to form the four reverse rings  6   a.    
     Since the longitudinal portion  6   c - 2 ′ is locked at the slot  6   c - 3 ′, it is prevented from restoring itself to a flat configuration. Thus, it is easy to perform an assembling operation when inserting the reverse rings  6   a ′ in the annular hollow space  8 . 
     Each reverse ring  6   a ′ is flexible and resilient. Thus, when it is locked at the slot  6   c - 3 ′, it has a restoring force urging it back towards a circular configuration from an elliptic configuration. That is, this restoring force acts to minimize the width of each of the outer peripheral passage C 1 , the inner peripheral passage C 2 . Similarly to the first embodiment, when the rotor  3  rotates, the flat cables  4  and  5  are pressed by the outer surfaces of the reverse rings  6   a ′. Accordingly, the flat cables  4  and  5  are prevented from freely moving in the widthwise (radial) direction of each passage. In this way, it is possible to suppress the generation of vibrations and abnormal sounds. 
     The cable reel of a third exemplary embodiment, shown in FIG. 7, is similar to that of the first and second embodiments except in the construction of the reverse member  6 ″ in the annular hollow space  8 . Other parts will not be described again. 
     As shown in FIGS. 7A and 7B, the reverse member  6 ″ has four elliptically curved reverse portions  6   a ″ formed by, for example, vacuum-moulding an annular plastics material sheet. The four reverse portions  6   a ″ are spaced at regular intervals in the circumferential direction of the reverse member  6 ″. The reverse member  6 ″ has a planar peripheral flange providing an outer annular portion  6   c ″ between its outer periphery and the reverse portions  6   a ″ and an inner annular portion  6   b ″ between its inner periphery and the reverse portions  6   a′.    
     This construction allows the formation of the reverse member  6 ″ to be completed by vacuum moulding, for example, and permits the reverse member  6 ″ to be simply inserted into the annular hollow space  8 , with the projecting reverse portions  6   a ″ disposed at the upward side. That is, it is easy to perform the assembly work. 
     For the passage of the flat cables  4  and  5  in the annular hollow space  8 , the gap between the upper surface of the inner annular portion  6   b ″, the peripheral surface of the rotor  3  and the inner peripheral surface of each reverse portion  6   a ″ forms the inner peripheral passage C 2 . The gaps (four gaps in total) between the reverse portions  6   a ″ circumferentially adjacent to each other provide the reverse passages C 3 . The gap between the upper surface of the outer annular portion  6   c ″, the inner peripheral surface of the base case  7  and the peripheral surface of each reverse portion  6   a ″ provides the outer peripheral passage C 1 . 
     By setting the width of the inner peripheral passage C 2 , the outer peripheral passage C 1 , and the reverse passage C 3  without providing an allowance, it is possible for the above construction to suppress the free movement of the flat cables  4  and  5  in the widthwise direction of the passages to a higher extent than the conventional construction. Even though the thickness of a bundle of the flat cables  4  and  5  is equal to the width of the passages, the flat cables  4  and  5  do not become incapable of moving because the reverse portions  6   a ″ are flexible and thus capable of flexing inward. 
     Reverse portions  6   a ″ are kidney-shaped and are radially (i.e. in directions parallel to the plane of the planar peripheral flange) resiliently flexible. Thus, the reverse portions  6   a ″ may be distorted in this direction by flat cables sandwiched between the reverse portions  6   a ″ and the inner peripheral surface of the base case. In this way, the flat cables are sandwiched and pressed by the resilient reverse portions  6   a′.    
     As in the case of the first and second embodiments, the third embodiment has the effect of reducing the number of component parts. 
     As will be apparent from the foregoing description of the first and second embodiments, the flat cable-reversing member which is accommodated in the annular hollow space of the cable reel may be formed in one piece from a flexible sheet. Thus, a plurality of the reverse loops are formed from one piece of material. In this way it is possible to reduce the number of component parts and manufacturing cost. Further, assembly is easy and time and labor are reduced. In particular, when the reverse loops are formed from an insulating sheet, it is possible to reliably insulate the flat cables. 
     Each reverse loop is made of the resilient flexible plastics sheet curved in a kidney shape when assembled in the cable reel. Each loop is radially expansible. Thereby each flat cable is sandwiched between the outer surface of a reverse loop and the inner surface of the annular hollow space and pressed between them. When the flat cable is wound, this sandwiching makes it difficult for the flat cable to move freely in a direction perpendicular to its winding direction. Thus it is possible to suppress generation of vibrations and abnormal sounds. 
     In the second embodiment, the end of each of the reverse loops is inserted into and locked at the slot formed at the base end portion of the arm of the ring. Thereby it is easy to ensure that the reverse loop keeps its cylindrical configuration. Thus it is easy to perform an assembling operation when accommodating the reverse loop in the annular hollow space. 
     In the third embodiment, by forming a plurality of the reverse portions integrally by vacuum moulding or the like of an annular sheet, a single member is accommodated in the annular hollow space. Thus, it is possible to reduce the number of component parts. In this case, the formation of the reverse portions is completed at the time of vacuum moulding, or the like, and it is easy to perform the assembling work. 
     While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention.