Abstract:
The present invention is to prevent an interference between a wire harness and a member disposed in the vicinity of the wire harness, and improve an endurance of the wire harness and stability of an electric power supply. A rotatable clamp for a wire harness includes an inner clamp for holding the wire harness and an outer clamp rotatably supporting the inner clamp, wherein the inner clamp is rotatable in one direction and is regulated to rotate in another direction orthogonal to the one direction. A unit utilizing the rotatable clamp has the wire harness swingably arranged between a sliding structure and the rotatable clamp disposed on a main body, wherein the wire harness is allowed to swing in the one direction so as to prevent the wire harness from interfering with a member disposed in the another direction. A minor axis and major axis of a protection tube with a flat shape for the wire harness correspond with the one direction and the another direction, respectively.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a rotatable clamp for swingably supporting a wire harness to supply electric power from a vehicle body to a sliding door thereof, and a unit utilizing the same.  
         [0003]     2. Description of the Related Art  
         [0004]      FIGS. 4 and 5  show a conventional power supply apparatus for a sliding door of a motor vehicle and a unit utilizing the same (for example, FIGS. 4 and 7 in JP, 2001-354085, A).  
         [0005]     The power supply apparatus  50  includes a synthetic resin protector  42  installed vertically in a sliding door  41 , a leaf spring  44  for urging a wire harness  43  to upwardly bend in the protector  42 , and a rotatable clamp  51  disposed in a vehicle body  47  supporting rotatably the wire harness  43  in a circumferential direction thereof.  
         [0006]     The protector  42  has a base and a cover (not shown). The base has a vertical base plate  52  and an outer wall  53 . When the cover is attached to the protector  42  with facing to the base plate  52 , an elongated lower opening  45  is formed at a lower end of the protector  42  for leading out the wire harness  43 .  
         [0007]     One side portion  43   a  of the wire harness  43  is led out through a front opening  54  of the protector  42  and connected to auxiliary units of the sliding door  41 . Another portion  43   b  of the wire harness  43  is guided through a step space  46  between the sliding door  41  and the vehicle body  47 , and supported at the rotatable clamp  51  in the vicinity of a step portion  48 . The wire harness  43  is connected to a wire harness, not shown, of the vehicle body  47  at the rotatable clamp  51  for supplying the electric power to the sliding door  41 .  
         [0008]      FIGS. 4 and 5  show the sliding door  41  fully closed and half opened, respectively. When the sliding door  41  is closed, the wire harness  43  is pulled backwardly with the rotatable clamp  51  against the urging force of the leaf spring  44 . When the sliding door  41  is half opened and the protector  42  comes closest to the rotatable clamp  51 , the leaf spring  44  urges upwardly the wire harness  43  to avoid drop-down and sandwiching of the wire harness  43  between the sliding door  41  and the vehicle body  47 .  
         [0009]     When the sliding door  41  is further moved backwardly, the wire harness  43  is forwardly pulled out against the urging force of the leaf spring  44  with the rotatable clamp  51  as a supporting point. When the sliding door  41  is started to open from the fully closed state, the sliding door  41  separates away from a curved guide rail, not shown, of the vehicle body  47 .  
         [0010]      FIGS. 6 and 7  show a conventional rotatable clamp  51  for a wire harness  43  and a unit utilizing the same disclosed in FIGS. 1 and 2 of JP, 2004-282879, A. The rotatable clamp  51  of  FIG. 6  has a horn-shaped harness guide  55  in contrast with that of  FIG. 7 . The detailed explanation for the portions of  FIG. 6  same as those of  FIG. 7  is omitted.  
         [0011]     The rotatable clamp  51  has an outer clamp  56  with a rectangular tube shape, which is separable above and below and has a separating face  60  as seen in  FIG. 6 , and an inner clamp  57  with a sphere shape supported rotatably in the outer clamp  56 . As shown in  FIG. 7 , the outer clamp  56  has inner supporting faces  58  with a circular section, which are disposed in an inner wall of the outer clamp  56  and facing to the inner clamp  57 , and a wide groove  59  with a circular section disposed between the inner supporting faces  58 . The groove  59  is formed around the inner wall of the outer clamp  56 .  
         [0012]     The inner clamp  57  is separable into two parts in a radial direction of the wire harness  43  and has a pair of projections  62  disposed in an outer wall of the inner clamp  57 . The projections  62  movably engage with the groove  59 . The backward and forward directions are defined here the inserting direction of the wire harness  43  to the rotatable clamp  51 .  
         [0013]     The inner clamp  57  has ribs  67  to be engaged with grooves  65  of a corrugated tube  64 , which is made of a synthetic resin and protects the wire harness  43 , at an inner wall of a harness insertion hole  63 . The corrugated tube  64  has the grooves  65  and ridges  66 , which are disposed in a circumference direction of the tube and arranged along a longitudinal direction thereof, and has a good flexibility. As shown in  FIG. 6 , the corrugated tube  64  terminates at the rotatable clamp  51  and an end portion of the corrugated tube  64  is supported with the inner clamp  57  and a plurality of covered electric wires  68  are led out to the motor vehicle body from the inner clamp  57 .  
         [0014]     As shown in  FIG. 7 , the wire harness  43  is guided out of the elongated lower opening  45  of the protector  42  having a base  69  and a cover  70 , and supported with the inner clamp  57 . The inner clamp  57  is rotatably supported with the outer clamp  56 . The outer clamp  56  is fixed to the vehicle body  47  with a bracket  71  as shown in  FIG. 6 .  
         [0015]     When the sliding door  41  is closed or opened as in  FIGS. 4 and 5 , the wire harness  43  swings backwardly and forwardly between the sliding door  41  and the vehicle body  47  and the inner clamp  57  rotates integrally with the wire harness  43  in the circumferential direction of the wire harness  43  so that twisting of the wire harness  43  is prevented.  
         [0016]     In the conventional rotatable clamp  51  and the unit utilizing the same  51 , when members such as a weather strip  72 , a part, or a structure are disposed in the vicinity of the inner clamp  57 , the member  72  may interfere with the corrugated tube  64  and damage the corrugated tube  64 .  
       SUMMARY OF THE INVENTION  
       [0017]     An object of the present invention is to provide a rotatable clamp for a wire harness and a unit utilizing the same to prevent an interference between a wire harness and a member disposed in the vicinity of the wire harness, and improve an endurance of the wire harness and stability of an electric power supply.  
         [0018]     According to a first object of the present invention, a rotatable clamp for a wire harness includes an inner clamp for holding the wire harness and an outer clamp rotatably supporting the inner clamp, wherein the inner clamp is rotatable in one direction and is regulated to rotate in another direction orthogonal to the one direction.  
         [0019]     Preferably, the outer clamp rotatably supports the inner clamp with engagement of a pair of projections and a pair of recesses.  
         [0020]     Preferably, a gap is formed between the pair of projections and the pair of recesses so as that the inner clamp is a little rotatable in the another direction.  
         [0021]     According to a second aspect of the present invention, a unit utilizing the rotatable clamp has the wire harness swingably arranged between a sliding structure and the rotatable clamp disposed on a main body, wherein the wire harness is allowed to swing in the one direction so as to prevent the wire harness from interfering with a member disposed in the another direction.  
         [0022]     Preferably, a minor axis and major axis of a protection tube with a flat shape for the wire harness correspond with the one direction and the another direction, respectively. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0023]      FIG. 1  is a vertical sectional view showing an embodiment of a rotatable clamp for a wire harness and a unit utilizing the same of the present invention;  
         [0024]      FIG. 2A  is a front view showing an inner clamp holding a protection tube with an oval shaped section;  
         [0025]      FIG. 2B  is a vertical sectional view showing a rotatable clamp holding the inserted protection tube with the oval shaped section;  
         [0026]      FIG. 3A  is a front view of the inner clamp rotated with 90 degrees from  FIG. 2A ;  
         [0027]      FIG. 3B  is a horizontal sectional view of the rotatable clamp rotated with 90 degrees from  FIG. 2B ;  
         [0028]      FIG. 3C  is a horizontal sectional view showing a wire harness swung to the right and left;  
         [0029]      FIG. 4  is a perspective view showing an embodiment of an arrangement of a wire harness of a conventional power supply apparatus of a sliding door when the sliding door is closed;  
         [0030]      FIG. 5  is a perspective view showing the arrangement of the wire harness when the sliding door is opened;  
         [0031]      FIG. 6  is an essential perspective view showing the arrangement of the wire harness utilizing the conventional rotatable clamp; and  
         [0032]      FIG. 7  is a vertical sectional view showing the arrangement of the wire harness utilizing the conventional rotatable clamp. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0033]      FIGS. 1-3  show an embodiment of a rotatable clamp for a wire harness and an embodiment of a unit utilizing the same according to the present invention. The reference signs of the present invention same as the conventional clamp and unit are not explained in detail.  
         [0034]     As shown in  FIG. 1 , a wire harness  43  is connected between a protector  42  disposed in a sliding door  41  and a rotatable clamp  1  disposed in a vehicle body  47 , which has a weather strip  72  for waterproof in the vicinity of the rotatable clamp  1 , similar to the conventional rotatable clamp and unit.  
         [0035]     The rotatable clamp  1  is made of a synthetic resin and has an inner clamp  57  and an outer clamp  4 . The inner clamp  57  is ball-shaped and has a pair of cylindrical projections (axles or protrusions)  62 , hereinafter projections, at an outer wall  61  thereof. The outer clamp  4  has a pair of bores (recesses)  2  with a circular section at an inner wall  3  thereof. The pair of projections  62  engage the inner clamp  57  with the outer clamp  4  with a very small angle θ of swing.  
         [0036]     The inner clamp  57  is vertically separable. The inner clamp  57  has coaxially a circular or oval-shaped (flat-shaped) insertion hole  63 , which has ribs  67  (projections) at an inner wall of the insertion hole  63  for engaging with grooves  65  of a corrugated tube  64  of the wire harness  43 .  
         [0037]     Front and rear ends of the inner clamp  57  are cut out in planes. In order to support the corrugated tube  64  with the inner clamp  57 , the inner clamp  57  is firstly separated into an upper and lower parts and the grooves  65  of the corrugated tube  64  are engaged with the ribs  67  of the inner clamp  57 . Then, the upper and lower parts are engaged together with a locking means such as locking claw and locking groove so as to support the wire harness  43  in the inner clamp  57 .  
         [0038]     The pair of the projections (axles)  62  are disposed at the outer wall  61  of the inner clamp  57  opposed to each other with respect to the center of the inner clamp  57 . It is preferable to resin-mold the projections  62  integrally with the inner clamp  57 .  
         [0039]     The outer clamp  4  has an outer wall  5  with a rectangular tube shape and a thick holding wall  6 , which is integrally disposed at an inner wall of the outer clamp  4  and at the center of the longitudinal direction of the outer wall  5 . A long inner wall of the holding wall  6  has a circular section and extends along the backward and forward directions of the rotatable clamp  1 . The long inner wall acts as the inner supporting face  3  for the inner clamp  57 . An inner diameter of the supporting face  3  is a little larger than the outer diameter of the inner clamp  57 .  
         [0040]     The inner supporting face  3  has the pair of bores  2  at the centers of an upper and lower walls of the holding wall  6 . An inner diameter of the bores  2  is a little larger than an outer diameter of the projections  62  of the inner clamp  57 . The pair of projections  62  are aligned with an axis line m. The inner clamp  57  is rotatable (swingable) to the right and left (the forward and backward directions of the vehicle body) with facing to the inner supporting face  3 . The inner clamp  57  rotates (swings) by a very small angle of θ 2  along the inner supporting face  3  so as that the corrugated tube  64  moves vertically with a small amount compared to the conventional unit.  
         [0041]     The angle θ 2  can be adjusted by changing the difference between the outer diameter of the projections  62  and the inner diameter of the bores  2  to regulate the rotation of the inner clamp  57 . The adjustment, however, is limited to the angle with which a lower face  64   a  of the corrugated tube  64  does not interfere with the member, or the weather strip  72  in the embodiment, disposed in the lower vicinity of the rotatable clamp  1 .  
         [0042]     In the conventional rotatable clamp  51  shown in  FIG. 7 , the lower face  64   a  of the corrugated tube  64  contacts with an inner edge  74  of an opening of the outer clamp  56 . However, the setting of the small angle θ 2  prevents the outer clamp  4  from interfering with the corrugated tube  64  and also a sliding wear of the corrugated tube  64 . It is also possible to completely eliminate the vertical movement of the inner clamp  57 , or the corrugated tube  64 , by adjusting the difference of the diameters of the projections  62  and bores  2 .  
         [0043]     When the sliding door  41  is closed or opened and the protector  42  is moved backwardly and forwardly with the sliding door  41 , the wire harness  43 , or the corrugated tube  64 , swings in the forward and rearward directions of the vehicle and the inner clamp  57  also simultaneously rotates about the axis line m of the pair of projections  62 .  
         [0044]     When the sliding door  41  is fully closed or fully opened from half opened state, the wire harness  43  is pulled to the back-and forth direction of the vehicle and the inner clamp  57  rotates a little upwardly in an arrow A to absorb the tension. When the sliding door  41  is half opened and the wire harness  43  is slacked, the inner clamp  57  rotates a little downwardly in the arrow A to form a bending portion  64   b  close to the rotatable clamp  1  with a large radius. The rotation of the inner clamp  57  in the direction of the arrow A is achieved with the difference of the diameters between the projections  62  and bores  2 . The small rotation of the inner clamp  57  keeps endurance of the wire harness  43  more than without the movement.  
         [0045]     The rotatable clamp  1  of  FIG. 1  is utilized for the corrugated tube  64  having both the circle and oval shaped (flat-shaped) sections.  FIGS. 2A-2B  and  3 A- 3 C show a rotatable clamp  1  utilized for a corrugated tube  64 ′ having the oval shaped section. The same parts of  FIGS. 2A-2B  and  3 A- 3 C as those of  FIG. 1  are not explained in detail.  
         [0046]     As shown in  FIGS. 2A-2B , an inner clamp  57  of the rotatable clamp  1  holds the corrugated tube  64 ′ with the major axis D 1  being vertical and along the direction of the axis line m of the pair of projections  62 .  
         [0047]     The inner clamp  57  has an insertion hole  63  with an oval section and disposed concentrically with an outer wall, or sphere,  61 . The insertion hole  63  has ribs, not shown, in an inner wall thereof and the ribs engage with grooves  65  of the corrugated tube  64 ′.  
         [0048]     When the inner clamp  57  holds a wire harness  43 , a large gap S is formed between an lower face  64 ′ a  of the corrugated tube  64 ′ and a lower end  74  of an opening of the outer clamp  4 . Pair of projections  62  of the inner clamp  57  are held with the outer clamp  4  so that the inner clamp  57  hardly rotates in a direction of an arrow A about the projections  62  and the gap S is kept. Thus, the large gap S prevents the corrugated tube  64 ′ from interfering with a member disposed close to the lower end  74  of the opening.  
         [0049]     The corrugated tube  64 ′ of  FIG. 2  has also a bending portion, not shown, same as in  FIG. 1  when extended to a sliding door. In the case of the oval shaped (flat shaped) section, the corrugated tube  64 ′ hardly bends in a direction of the major axis D 1 . As shown in  FIG. 2A , the major axis D 1  of the corrugated tube  64 ′ is vertical so that a bending diameter is significantly regulated and a slack of the corrugated tube  64 ′ is minimized.  
         [0050]     As shown in  FIGS. 3A-3B , a minor axis D 2  of the corrugated tube  64 ′ is orthogonal to the axis line m of the pair of projections  62 . A large gap S′ is formed between side faces of the corrugated tube  64 ′ and side ends  74 ′ of the opening of the outer clamp  4 . When the outer wall  5  of the outer clamp  4  is tube-shaped and has a square section, the gap S′ of  FIG. 3B  is larger than the gap S of  FIG. 2B  to the difference between the major axis D 1  and minor axis D 2 .  
         [0051]     As shown in  FIG. 3C , the large gap S′ prevents the corrugated tube  64 ′ from strongly interfering with the side ends  74 ′ of the opening when the sliding door is closed and opened. Accordingly, the corrugated tube  64 ′ has an improved endurance.  
         [0052]     In the embodiment, the outer clamp  4  has the straight outer wall  5 . The outer wall  5  may have a horn-shaped guide wall as shown in  FIG. 6  of the conventional type.  
         [0053]     In the embodiment, the inner clamp  57  has the spherical outer wall  61 . The inner clamp  57  may have a rugby ball shape with a pair of projections disposed along the major axis, and have a rectangular shape with a pair of projections  62 , or axles, disposed at an upper and lower surfaces. In the case of the rectangular shape, the inner clamp  57  is supported with the outer clamp having a large size and rotatable in the horizontal direction.  
         [0054]     In the embodiment, the pair of projections  62  are disposed on the inner clamp  57  and the bores  2  engaged with the projections  62  are disposed on the outer clamp  4 . The pair of projections  62  can be disposed on the inner wall of the outer clamp  4  and the bores  2  can be disposed on the outer wall  61  of the inner clamp  57 . The inner clamp  57  may have the projection  62  and bore  2  and the outer clamp  4  has the bore  2  and projection  62  corresponding to the inner clamp  57 . In the embodiment, the bores  2  are formed on the inner wall of the outer clamp  4 . Through-holes can be formed on the outer clamp  4 .  
         [0055]     In the embodiment, the corrugated tube  64  is utilized for protecting the wire harness  43  arranged between the vehicle body  47  and the sliding door  41 . A net tube made of a synthetic resin or a flat surface tube made of vinyl or urethane can be utilized in place of the corrugated tube  64 . In this case, a sharp projection is pierced into the protection tube for fixing or the protection tube is fixed to the inner clamp  57  with adhesion.  
         [0056]     In the embodiment, the rotatable clamp  1  is adapted to the power supply apparatus  50  having the protector  42  and the leaf spring  44  urging upwardly the wire harness  43 . The wire harness can be arranged in a loop or reel manner in a curved or rectangular shaped protector. The wire harness can be held vertically and swung like a pendulum. Other resilient members such as helical spring or coil spring can be utilized in place of the leaf spring  44 . A repulsive force against bending of the wire harness can be utilized in place of the resilient members.  
         [0057]     In the embodiment, the protector  42  is disposed vertically. The protector with a lower height can be disposed inside the sliding door. The protector can be disposed horizontally on the vehicle body in place of the sliding door  41 . The rotatable clamp  1  can be disposed in the sliding door in place of the vehicle body. The wire harness  43  can be arranged directly in the sliding door without the protector  42 .  
         [0058]     The rotatable clamp  1  and the unit utilizing the same can be adapted to a sliding door of a vehicle other than the motor vehicle and a sliding door of a machine tool or testing machine other than the vehicle for supplying electric power to the main body of the vehicle body, and the tool or machine. The present invention is adapted to a sliding structure such as the sliding door and a main body such as the vehicle body.