Abstract:
A corrugated tube with a longitudinal slit is loaded with electrical wires and the slit is locked. This process is effected using one device and in a single step. The corrugated tube is provided on its outer surface with circular peaks and troughs alternating along the axial direction. The portions facing one another across the slit are provided with convex and concave shapes along the circumference of the tube forming female and male locking portions. The male locking portion is inserted under the female locking portion, so as to lock the slit. An automatic locking device has a tubular guiding unit having a slanted tube part, and a tubular locking unit. The wires pass through the slanted tube part and the tubular locking unit. The tubular guiding unit is inserted into the slit, and the corrugated tube inside the tubular locking unit. When the device and the corrugated tube are moved relative to each other in the longitudinal direction, the wires are transferred from the device into the corrugated tube and the slit is automatically locked.

Description:
This is a division of U.S. patent application Ser. No. 08/922,352, filed Sep. 3 1997, U.S. Pat. No. 6,024,329 the contents of which are herein incorporated by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a wiring harness used in automobiles, and a device for protecting the wiring harness. More specifically, the invention concerns a corrugated tube, through which the wiring harness passes and is protected thereby. Such a corrugated tube may have a longitudinal slit along the axial direction. In this construction, the tube is first opened along the slit, a group of electrical wires is loaded through the opening, and the opening is closed. The invention also relates to a device for inserting a group of electrical wires into the corrugated tube, which can create a longitudinal slit in the corrugated tube, insert the group of wires therein, and close and lock the tube at the slit. 
     2. Description of Background Information 
     In the prior art wiring harness used in automobiles, the main portion of the harness is placed within a corrugated tube for protection. As shown in FIG. 1A, a corrugated tube  1 -— 1  can have a longitudinal slit S along the axial direction; as shown in FIG. 1C, the slit portion can have an overlapping zone R in the axial direction. As shown in FIG. 1B, a corrugated tube  1 - 2  may be uniform (i.e., no slit). 
     In the case of the corrugated tube  1 - 2  without a slit, a connector housing (not shown) to be mounted on an end portion cannot pass through the corrugated tube  1 - 2 . Therefore, the electrical wires must first be inserted through the corrugated tube  1 - 2 , whereupon the connector housing is then mounted on the end portion of the wires as a final step. A such, the end portion of each electrical wire cannot be loaded into the connector housing by an automatic process. This prevents automating the mounting process of the wiring harness. 
     For the corrugated tube  1 -— 1  with a slit, the group of electrical wires are loaded simply by opening the tube at the slits. The connector housing can thus be connected to the group of electrical wires beforehand. Accordingly, the end portion can be inserted into the connector housing by automation. However, when the corrugated tube  1 -— 1  is bent as shown in FIG. 2, the slit S may open. It is therefore necessary to seal the slit after the electrical wires are inserted into the tube. To this end, tape can be wound around the outer circular surface of the tube  1 -— 1 . However, this tape-winding step is cumbersome, increasing manufacturing time and costs. This step is also necessary for the corrugated tube  1 - 2  with an overlapping slit shown in FIG.  1 C. 
     Referring now to FIG. 3, a prior art device  3  inserts the electrical wires into the above-mentioned tubes  1 -— 1  or  1 - 3  with a slits. The electrical wires W are inserted initially through the device  3 . Device  3  open&#39;s slits and installs wires W into the corrugated tube  1  as device  3  moves down the length of the tube. In this construction, the connector housing C can be connected beforehand to the wire end portion. 
     However, device  3  only serves to pass the wires W into the corrugated tube, and does. not otherwise obviate the need for tape. 
     SUMMARY OF THE INVENTION 
     To overcome this problem, longitudinal zones flanking the slit may be defined on the outer surface of the tube. Peak portions in those zones may be provided with corresponding female and male locking portions extending from the slit in the circumferential direction. For example, these female and male portions may use sequential concave and convex structures, viewed from the axial direction of the tube. This configuration extends from the slit side along the circumferential direction of the tube. When these male and female configurations are superposed, the tube is locked. 
     When such a tube is used, there is no need to close the slit with tape. However, after the wires are installed, a supplementary step of superposing the female and male locking portions must be performed. 
     When the locking portions are installed on all the peak portions along the entire length of the corrugated tube, locking work is rather cumbersome. Further, when the electrical wires are tightly contained in the tube, a strong outward force is exerted on the slit of the tube. A correspondingly strong force is therefore needed to superpose the female and male locking portions. Such a locking step can be extremely difficult for the assembly workers. Moreover, after the electrical wires are installed through the tube, the tube must be locked during a separate step. This procedure requires a two-step operation (i.e., installation followed by locking), increasing manufacturing time and associated costs. 
     To enable automation of the operation of inserting the wire end portion into the connector housing, a corrugated tube preferably has a slit. The slit may be designed such that it can be closed easily. There is therefore no need for the application of tape. Further, it is desirable to combine the loading of the electrical wires into the tube and the automatic locking of the tube thereafter into a single step. 
     To this end, there is provided a corrugated tube for protecting a wiring harness including of a plurality of electrical wires. The tube extends in a longitudinal direction and has an outer surface with alternating peak and trough sections formed along the longitudinal direction thereof The tube has a longitudinal slit with two sections facing each other across the slit. Each section has a sequential concave and convex shaped cross sections extending from the slit along the circumference of the tube defining female and male locking portions, respectively. The male locking portion fits into the female locking portion, when locked, from the inside of the tube, so that the concave and convex configurations of the malelocking portion are securely superposed with the corresponding concave and convex configurations of the female locking portion to close and lock the slit. 
     In this corrugated tube, the female locking portion is wider in the longitude direction of the tube that than the male locking portion. 
     The female locking portion may have sequential convex, concave and convex shapes forming a series of a successive L-shapes extending from the slit along the circumference of the tube. The male locking portion has sequential concave and convex shapes forming; a series of successive V-shapes extending from the slit along the circumference of the tube. The plurality of electrical wires are loaded by opening the slit, and the slit is subsequently closed and locked by superposing the male and female locking portions. 
     There is also provided a method of automatically loading and locking a plurality of electrical wires into a corrugated tube. A device is prepared having tubular guiding unit and a tubular locking unit. The guiding At has a top projection part, a bottom slit-opening part and a slant tube part therebetween, and first and second ends, the slant tube part being obliquely arranged from the top projection part at the first end towards the bottom slit-opening part at the second end. The locking unit has a first and a second end, and accommodates the corrugated tube and locks the female and male locking portions. The second end of the tubular guiding unit and the first end of the tubular locking unit are longitudinally connected, such that the slant tube part and the tubular locking unit are inclined relative to each other. The plurality of electrical wires are loaded into the tubular guiding and locking units. The bottom slit-opening part of the tubular guiding unit is inserted into the slit The corrugated tube is inserted into the tubular locking unit. The tubular locking unit is moved relative to the corrugated tube, whereby the slit is opened, the electrical wires are loaded into the corrugated tube, and the female and male locking portions are locked. 
     There is further provided a device for loading and locking a plurality of electrical wires into the corrugated tube having an inner and an outer diameter. The device includes a tubular guide unit for guiding the plurality of electrical wires. The unit has a first and a second end. At least a slant tube part obliquely extends from the first end towards the second end. The slant tube part has an external diameter smaller than the internal diameter of the corrugated tube. A tubular locking unit has a first and a second end to lock the slit The unit has an inner circular surface along a longitudinal direction and a gradually decreasing inner diameter from the first end towards the second end along the longitudinal direction. The diameter at the second end is equal to the external diameter of the corrugated tube when it is locked. The tubular locking unit can accommodate the corrugated tube and locking female and male locking portions. The second end of the tubular guiding unit and the first end of the tubular locking unit are longitudinally connected, such that the slant tube part and the tubular locking unit are inclined with respect to each other. In use, the unit accommodates the plurality of electrical wires. When the when the slit-opening part is inserted into the slit, the tubular locking unit contains the corrugated tube and such that when there is a relative movement between the tubular guiding unit and the corrugated tube, the plurality of electrical wires are transferred into the corrugated tube, the female and male locking portions are gradually brought closer together towards the second end of the tubular locking unit, and the slit is locked. 
     In the above device, the tubular guiding unit may further comprise a slit-opening part having a substantially round cross-section at the first end of the tubular guiding unit. The slit-opening part gradually fuses with the slant tube part towards the second end thereof. When there is a relative motion between the slit-opening part and the corrugated tube, the slit is gradually opened and the plurality of electrical wires are loaded into the corrugated tube. 
     The tubular guiding unit may further include a projection along the slant tube part at a position distal to the slit-opening part. The tubular guiding unit and the tubular locking unit are connected by this projection. 
     The inner circular surface of the tubular locking unit may be provided with a pair of longitudinal ribs spaced from each other and adapted to mate with corresponding concave shape of the female and male locking portions. The space between the pair of ribs gradually narrows from the first end of the tubular locking unit towards the second end thereof When the corrugated tube approaches the second end, the female and male locking portions are superposed by virtue of a force exercised by the narrowing ribs. 
    
    
     BRIEF DESCRIPTION OF THE FIGURES 
     The above and other objects, features and advantages of the invention will be made apparent from the following description of the preferred embodiments, given as a non-limiting example, with reference to the accompanying drawings, in which: 
     FIGS. 1A,  1 B and  1 C show prior art corrugated tubes with a slit, without slit and with an overlapping zone, respectively; 
     FIG. 2 schematically shows a prior art corrugated tube when the slit is deflected; 
     FIG. 3 shows a prior art device for loading electrical wires into a corrugated tube, and illustrates its operation; 
     FIGS. 4A and 4B respectively show a cross-sectional view the cross-section being taken through the ridge portions, and a perspective view of an embodiment of the corrugated tube according to the present invention; 
     FIG. 5 shows a cross-sectional view of the corrugated tube with a slit, when the slit is closed and locked, a cross-sections being taken through the ridge portions; 
     FIG. 6 shows a plan view of female and male locking portions before locking; 
     FIGS. 7A and 7B, show a perspective view of a preliminary formed corrugated tube and a cross-sectional view thereof the cross-sections being taken through the ridge portions, when forming the slit in a container, respectively; 
     FIGS. 8A ad  8 B, show a cross-sectional view of the corrugated tube when loaded with electrical wires and when locked, respectively the cross-section being taken through ridge portions and a member around the wires; 
     FIG. 9 illustrates a process of loading wires into the corrugated tube using the loading- and-locking and-locking device acccording to the invention; 
     FIG. 10 shows a perspective view of the loading-and-locking device of FIG. 9; 
     FIG. 11 shows a cross-sectional view of the loading-and-locking device of FIG. 9; 
     FIG. 12 shows a schematic side view of the loading-and-locking device of FIG. 9; 
     FIG. 13 shows a schematic plan of the loading-and-locking device of FIG. 9; 
     FIGS. 14A and 14B, show cross sections along the lines A—A and B—B, respectively; of FIG. 9 the cross-sections being taken through ridge portions and a member around the wires; and 
     FIG. 15 shows a variant type of the loading-and-locking device according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As shown in FIGS. 4A and 4B, the corrugated tube  10  according to the present invention has a plurality of circular peak sections  12  and trough sections  13  on its outer surface, alternatively provided on tube  10  at a predetermined pitch along the axial (longitudinal) direction. Tube  10  has a longitudinal slit  11  along the longitudinal direction of the tube. 
     The longitudinal slit  11  forms separated first and second longitudinal zones along the slit. The first longitudinal zone defines a plurality of first peak sections  12   a , while the second longitudinal zone defines a plurality of second peak sections  12   b . The first and second peak sections  12   a  and  12   b  are provided with a concave and convex shapes respectively. As discussed below, these shapes are closed in single motion to lock slit  11 . 
     The first peak section  12   a  makes up a female locking portion  14 . Female locking portion  14  includes, sequentially from the slit  11  counterclockwise in FIG. 4, an inserting convex shape  15  having an L-shaped cross-section and an open edge, a stopper concave shape  16 , a stopper convex shape  17 , and a positioning concave shape  18  for defining the position during cutting (discussed below). The second peak section  12   b  is a male locking portion  19 . Portion  19  includes, clockwise in FIG. 4, a receiving convex shape  20  preferably having a V-shaped cross-section, a stopper concave shape  21 , a stopper convex shape  22 , and a positioning concave shape  23  for defining the position during cutting. 
     As shown in FIG. 6, the insertion convex shape  15 , stopper concave shape  16  and stopper convex shape  17  of the female locking portion  14  have a width W1 along he longitudinal direction, which is wider than the width W2 of the corresponding shapes  20 ,  21 , and  22  of the male locking portion  19  (i.e., W1&gt;W2). Thus, the male locking portion  19  easily fits under the female locking portion  14  (viewed from the tube axis). 
     Also, the corrugated tube  10  is provided with a longitudinal notch  24  having a roughly inverted V-shaped cross-section. Notch  24  extends longitudinally along tube  11  at a position distal to slit  11 . Further, the stopper concave shape  16  of the female locking portion  14  has a length L1 around the circumference of tube  10 , which is shorter than the length L2 of the corresponding stopper concave shape  21  of the male locking portion  19  (i.e., L1&lt;L2). 
     As shown in FIGS. 7A and 7B, the corrugated tube  10  is initially fabricated in a circular form in which the edge of the inserting convex shape  15  of the female locking portion  14  and the receiving convex shape  20  of the male locking portion  19  are integrally connected by a radially rising wall  25 . The wall  25  is cut by a cutter  27  to form slit  11 , i e., female locking portion  14  and male locking portion  19  separate to define slit  11  therebetween. When cutting with the cutter  27 , the tube  10  is installed in a container  28  having a pair of holding ribs  29  which engage concave shapes  18  and  23  respectively, so that the tube  10  is held in the appropriate position. 
     A connector housing (not shown in the figures) is mounted at the end of a plurality of electrical wires. In this state, as shown in FIG. 8A, the slit  11  of the corrugated tube  10  is open and the connector housing is laterally inserted thereinto through the slit. 
     Subsequently, the female and male locking portions  14  and  19  on the opposing sides of the slit  11  are pressed together. The male locking portion  19  fits into the radially inner side of the female locking portion  14 , as shown in FIGS. 5 and 8B. Notch  24  provides sufficient flexibility to permit these opposing sides of slit  11  to be brought together and locked. 
     In this locking process, the receiving convex shape  20  (inverted V shape in the figures) is inserted under the convex shape  15  (L form), and then moves over the stopper concave shape  16  and finally fits into the stopper convex shape  17 . At the same time, the stopper concave shape  21  and convex shape  22  of the male locking portion  19  are tightly superposed on the inner side of the stopper concave shape  16  and the inserting convex shape  15  of the female locking portion  14 , respectively. 
     As discussed above, the three sequential concave and convex formations of the male locking portion  19  engage their counterparts at the underside of the female locking portion  14 . Especially, the fitted stopper concave shapes  16  and  21  are flanked by the respectively fitted stopper convex shapes. All the peak sections  12  at the sides of the slit  11  thus securely lock the female locking portion  14  and the male locking portion  19 . Accordingly, it is not necessary to wrap the tube  11  in tape as required in the prior art. 
     However, the present invention is not limited to the aforementioned embodiment. The locking mechanism may be provided using only some of the peak sections near the slit edges, or at a predetermined pitch along the slit  11 , instead of on all of the peak sections along the slit line as mentioned above. 
     Further, the locking mechanism is preferably provided on the peak sections of the tube, but not on the trough sections thereof. Thanks to this configuration, the flexibility of the tube is not impaired. After being loaded with a wiring harness, the tube can still be curved or bent as desired. 
     Moreover, only part of a circular corrugated tube is cut to define a slit between female and male locking mechanisms. Carrying into practice of the present invention is therefore very easy. 
     The present invention also relates to a method for loading a plurality of electrical wires W into the above-mentioned corrugated tube  10  and locking the tube. It further concerns a device specifically designed for this purpose. 
     FIG. 9 shows a corrugated tube  10  and a wire-loading device  30  by which a plurality of electrical wires are installed in the corrugated tube, where the slit of the tube is closed and locked. 
     The shape of wireloading device  30  is shown in FIGS. 9-13. A tubular guiding unit  32  for guiding the electrical wires includes at least left and right wing parts (slant tube part)  32   a  and  32   b  integrally linked at the underside of each wing. Guiding unit  32  connects with a tubular locking unit  33  at a predetermined angle of inclination. The two units can be formed integrally from a resin. Tubular locking unit  33  has a left and a right wing  33   a  and  33   b  integrally linked at the underside of each wing. The wings of both units  32  and  3 : 3  extend upwardly to form a projection having opposed portions  34   a  and  34   b . Thus, the projection extends continuously from the tubular guiding unit  32  to the tubular locking unit  33 . The units  32  and  33  are opened by separating the opposed portions  34   a ,  34   b , so that the electrical wires W can be installed in units  32  and  33 . 
     Wings  32   a  and  32   b  of the tubular guiding unit  32  have an external diameter R 1  smaller than the internal diameter of the corrugated tube  10 . The tubular guiding unit  32  may also be provided with a slit-fitting part  35  for opening the slit  11  of the corrugated tube  10 . The slit-fitting part  35  is provided under wings  32   a  and  32   b  and extends vertically forward of device  30 . 
     This slit-fitting part  35  is formed by linking a semicircular shaped cross section to each of the wings  32   a  and  32   b  through a neck part  35   a . When both wings  32   a  and  32   b  Acre pressed against each other, the slit-fitting part  35  has a round cross-section. The shape of the slit-fitting part  35  gradually merges into wings  32   a  and  32   b  moving from the front of guiding unit  32  to the rear, ending in a substantially circular rear opening  32   d .    
     Wings  32   a  and  32   b  of the tubular guiding unit  32  are integrally formed with the left and right wings  33   a  and  33   b  of the tubular locking unit  33  at the top ends thereof, respectively, so that rear opening  32   d  of the tubular guiding unit  32  faces the front opening  33   c  of the tubular locking unit  33 . A space S formed between the bottom-side outer surface of the tubular guiding unit  32  and the bottom-side inner surface of the tubular locking unit  33  corresponds to the thickness of the corrugated tube  10 . 
     The tubular locking unit  33  has a gradually narrowing diameter along its axis, from the forward end towards the rear thereof The narrow end  33   d  has an inner diameter equal to the outer diameter of the corrugated tube  10  when it is locked. 
     The inner circular surface of the tubular locking unit  33  is provided with a pair of ribs  33   f  and  33   g  at both sides of the upper opening  33   e  thereof. The pair of ribs  33   f  and  33   g  mate with the concave shapes  18  and  23  of the female and male locking portions  14  and  19  of the tube  10 . Ribs  33   f  and  33   g  extend along the axial direction of unit  33 . The distance D between ribs  33   f  and  33   g  gradually narrows towards an end  33   d  of the tubular locking unit  33 . At the rear end  33   d  of tubular locking until  33 , distance D is small enough such that female locking portion  14  mates with male locking portion  19 . Further, as shown in FIG. 11, the inner surface of the tubular locking unit  33  is provided with a rib  33   h  at its bottom, which slidably mates with notch  24  in the corrugated tube  10 . 
     By using the above device, the electrical wires W are loaded into the corrugated tube  10 , and the slit locked, as follows. 
     The opposed portions  34   a  and  34   b  of the projection of the device  30  are opened. The wires are loaded through the&amp; tubular guiding unit  32  to the tubular locking unit  33 , as shown by the dotted lines in FIGS. 11-13. In this state, the wires pass from the opening  32   d  of the slant tube part  32  through the guide-side opening  33   c  of the tubular locking unit  33 . 
     The corrugated tube  10  is then held with the slit  11  facing upwards. The neck  35   a  linking the tubular guiding unit  32  and the slit-fitting part  35  is then inserted into slit  1 . Thus, the slit-fitting part  35  is fitted into the corrugated tube  10 . 
     Thereafter, as device  30  moves along corrugated tube  10 , the shape of outer circular surface of the slit-fitting part  35  forces slit  11  gradually open wider and wider. When the edge of the corrugated tube  10  is advanced into the guiding-side opening  33   c  of the tubular locking unit  33 , the bottom part of the corrugated tube  10  is inserted into the space S formed between the tubular guiding unit  32  and the inner surface of the tubular locking unit  33 . The corrugated tube  10  is thus guided into the tubular locking unit  33 . 
     When notch  24  of the tube  10  engages with the rib  33   h  of the tubular locking unit  33 , the pair of ribs  33   f  and  33   g  on the tubular locking unit  33  engage concave shapes  18  and  23  provided at the upper part of the tube  10 , as shown in FIG.  14 A. 
     When the corrugated tube  10  is inserted along the inner circular surface of the tubular locking unit  33 , the electrical wires contained in the tubular guiding and locking units  32  and,  33  are inserted into the corrugated tube  10 , as shown in FIG.  14 A. Namely, the electrical wires contained in the tubular locking unit  33  automatically transfer into the corrugated tube  10  as locking unit  33  moves along tube  10 . 
     As the corrugated tube  10  advances relative to the tubular locking unit  33  towards its end  33   d , the distance between the ribs  33   f  and  33   g  narrows. The concave shapes  18  and  23  engaged with these ribs are brought closer together. As shown in FIG. 14B, when the tube  10  arrives at the edge  33   d  of the tubular locking unit  33 , the female and male locking portions  14  and  19  of the tube  10  completely superpose, closing slit  11 . 
     Accordingly, when the corrugated tube  10  exits from the edge  33   d  of the device  30 , the wires are loaded in the tube  10  and the slit  11  is locked. 
     Although, in the above-description, the corrugated tube  10  is moved vis-a-vis the device  30 , it can be done inversely to obtain the same result and/or both items can be moved simultaneously. 
     FIG. 15 shows a variant type of the device  30 , wherein the slit-fitting part  35 ′ provided at the bottom part of the tubular guiding unit  32  has a flat shape. This part  35 ′ is formed by flatly bending the left and right wings of the tubular guiding unit  32 , at the position located under (in FIG. 15) the wings  32   a  and  32   b . In this configuration, the slit-fitting part  35 ′ is inserted into the slit  11  of the tube  10 . The tube  10  or the device  30 ′ (or both) is then moved in the longitudinal direction. The slit  11  reaches the outer circular surface  32   c  of the wings  32   a  and  32   b , automatically widening slit  11 . The other functions are the same as in the aforementioned embodiment. 
     The bottom part of the tubular guiding unit  32  may be formed so as not to include a, slit-fitting part. In such a case, the slit  11  of the corrugated tube  10  is directly opened along the bottom outer surface of the guiding unit  32 . When the slit  11  is opened, the corrugated tube  10  is inserted into the tubular locking unit  33  and fitted therewith. Then, the electrical wires W are loaded in the tube  10  and the slit  11  is locked. 
     By using the device  30  according to the invention, it is unnecessary to wrap the tube in tape. Further, the wire is installed and the slit closed in a single step, substantially reducing manufacturing time and associated costs. A worker&#39;s workload is therefore greatly reduced and the work efficiency is enhanced. Further, device  30  can be easily manufactured by molding a resin and does not raise manufacturing costs. 
     Although the invention has been described with reference to particular means, materials and embodiments it is to be understood that the invention is not limited to the particulars disclosed and extends to all equivalents within the scope of the claims. 
     The present application is related to Japanese Patent Application No. 8-232783, filed Sep. 3, 1996, and Japanese Patent Application No. 8-273442, filed Oct. 16, 1996, the disclosure of which is incorporated by reference in their entireties herein.