Patent Publication Number: US-6907810-B2

Title: Perforated braid with dual core yarns and braiding apparatus

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a braiding apparatus and a perforated braid, which has dual cores. More particularly, a braiding apparatus for braiding the perforated braid with constant intervals of perforation forms a first braid section to braid one strand with a plurality of yarns, sequential braid section to braid a certain length of braid with two strands and another sequential braid section to braid final strand with the previous strands. The braiding apparatus equips a pair of carrier contour changers mounted underneath a carrier guide plate, which has a plurality of carriers, carrier contours and a pair of coupling holes to braid one or two strands of yarns by connecting or separating carrier contours. 
   2. Description of the Related Art 
   A braid is generally formed with a plurality of yarns that cross each other. The braid is used in various fields such as wire coatings, string hoses, binding twines and the like. The tubular braid is formed with a plurality of yarns braided around an outer circumferential surface of core yarns, wires or binding twine. This method allows the braided yarns to stretch or bend. Therefore, the flexible braided core yarns formed around the wire or twine provide protection for the inner substances from external impact or contamination. Currently, braids are widely used as binding twines for commodities such as shoes, apparels or the like as well as for specific uses. 
   A conventional braiding apparatus consists of a carrier guide plate provided with carrier contours along with a plurality of carriers, a plurality of feed goats for rotating a plurality of carriers along the carrier contours on the carrier guide plate, a drive gear for driving the plurality of feed gears and a plurality of rollers for winding the braided twine. 
   As shown in  FIG. 1 , a braiding apparatus for braiding a common tubular braid comprises two carriers crossed with each other and forming a slight in a zigzag pattern formed on a guide plate  100 . A plurality of feed gears opposed to the crossing center of the carrier contours is disposed at a lower portion of the guide plate  100 . Therefore, when the plurality of feed gears are driven altogether by the drive gears, a plurality of carriers  101 ,  101 ′ installed on the carrier guide plate  100  are rotated and moved along the carrier contours on the guide plate  100 . 
   The plurality of carriers  101 ,  101 ′ rotates around the center of the guide plate  100  while traveling along the carrier contours. In this way, each of the carriers  101 ,  101 ′ rotates and moves along the carrier contours of the guide plate  100  while crossing with each other. Thus, a plurality of yarns  102 ,  102 ′ are braided to form a tubular braid  103  by the crossing and rotating of the carriers  101 ,  101 ′, on the outer circumferential surfaces of core yarns. 
   However, the above-described tubular braid has a tubular common cross-section such as a shoe strap. The round braid is easily loosened due to loosing the friction force when the braid is moving very hard. For this reason, various kinds of binding means are introduced to solve the loosening problem. 
   To solve this problem, for example, a polygonal braid and its braiding apparatus are disclosed in Korean Patent No. 348360. The braiding apparatus for braiding a polygonal braid such as a rectangular braid as well as a triangular braid equips a carrier guide plate constructed such that a plurality of carrier contours are crossed with each other with an array of feed gears corresponding to the carrier contours. 
   Accordingly, the polygonal braids such as rectangular or triangular braids are used for binding twines of shoes or apparel. The polygonal braid has a larger sectional area than a tubular braid to increase the friction forces between the braids, which are leading to improve the binding force. The laces of shoes and apparels which are applied with the polygonal braids would not easily become loosened due to the increase in the binding force. 
   However, the above-described polygonal braid applied to the laces has disadvantages, particularly when knot is required to be frequently tied and untied. In this situation, the binding portion would have troubles or difficulties to untie easily. 
   When a knot is formed on a braid, the knot will exert unusual binding force on the braid depending on a person who makes knot. Thus, if the binding is made with strong force, it will be difficult to untie the knot. Contrary, if the binding is made with weak force, the knot will easily be loosened. Therefore, the binding means with proper binding force must be developed to solve such problems. 
   Relating to a fishing net or fishing line, there are used either tubular or polygonal braids to make continuous cross twines. The cross pattern is braided in such a manner that the branch lines are connected to the main lines with constant intervals. However, the cross patterns have a problem in that the binding portions of the branch line are easily slipped off thus displacing its original position and massing up the fishing net or fishing line after a certain time has elapsed. It would be burdensome and expensive to correct the displacement of the massed up binding portions in fishing net or fishing line. 
   Therefore, a new concept of braids with knot used for the various purposes is developed to prevent the displacement or loosening the binding portion. 
   SUMMARY OF THE INVENTION 
   An objective of the present invention is to provide a perforated braid with dual core yarns and a braiding apparatus which form a first braid section of a certain length to braid one strand with a plurality of yarns of carriers, sequential braid section of a certain length to braid with two strands of braid and another sequential braid section of a certain length to braid with previous strands to produce a perforated braid having continuous perforations with constant intervals. The braiding apparatus comprises a carrier contour changer mounted on a guide plate with a plurality of carriers to braid one strand and two strands of braid by connecting or separating carrier contours. Because the binding force is increased, the present braid is suitable applying to the binding twines as well as fishing nets or fishing lines that have binding portions between main lines and branch lines. 
   Another objective of the present invention is to provide a braiding apparatus which has a carrier guide plate formed with carrier contours, a base plate spaced underneath the guide plate at a certain interval, a plurality of carriers moving along the carrier contours formed on the carrier guide plate, a plurality of feed gears rotatably mounted on the base plate corresponding to feed discs fixed to the top of a feed gear shaft, the feed discs interposed to the carrier base disposed lower part of the carrier, wherein the carrier guide plate is provided with two core yarn holes, a plurality of coupling holes radially formed circumferential core yarn holes, two tracks of carrier contours formed in a zigzag pattern to a certain depth along the circumferential coupling holes and four square slots formed at crossing portions of the carrier contours in four directions from the center of the carrier guide plate, and each of the carrier contours are separately formed with inner and outer path around the coupling holes to cross the carrier contours repetitively; the feed discs mounted on top of the shafts interposed to the carrier base disposed at the lower part of the carrier; carrier contour changers mounted underneath the carrier guide plate. A pair of carrier contour changers mounted underneath the carrier guide plate and inserted into four square slots for operationally providing alternative tracks of said carrier contours to cross and separate the carriers at crossing portions of said carrier contours, and a pair of actuators mounted underneath said base plate connected to said carrier contour changers through operating rod, link and change rod, for repetitively crossing and separating operations. A pair of carrier contour changers mounted underneath the carrier guide plate further comprises a pair of change block assemblies and operating frames, the change block assemblies. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view showing a braiding apparatus for producing a common tubular braid. 
       FIG. 2  is an exploded perspective view illustrating a substructure of braiding apparatus of the perforated braid according to the present invention. 
       FIG. 3  is a cross-sectional view showing the semi-assembled substructure of the braiding apparatus of the perforated braid according to the present invention. 
       FIG. 4  is an overall perspective view of a carrier contour changer according to the present invention. 
       FIG. 5  is an exploded perspective view of principle parts of the carrier contour changer according to the present invention. 
       FIG. 6   a  is a side cross-sectional view showing the operating state of the carrier contour changer crossing the carrier contours. 
       FIG. 6   b  is a cross-sectional perspective view showing the operating state of the carrier contour changer crossing the carrier contours. 
       FIG. 7   a  is a side cross-sectional view showing the operating state of the carrier contour changer splitting the carrier contours. 
       FIG. 7   b  is a cross-sectional perspective view showing the operating state of the carrier contour changer splitting the carrier contours. 
       FIG. 8  is a plane view showing an arrangement of a plurality of carriers and feed discs on a carrier guide plate according to the present invention. 
       FIG. 9  is a diagram showing two tracks of the carriers on the carrier guide plate when one strand of carriers is braided by the braiding apparatus according to the present invention. 
       FIG. 10  is a diagram showing tracks of the carriers on the carrier guide plate when two strands of carriers are braided by the braiding apparatus according to the present invention. 
       FIG. 11  is an expansive perspective view of a perforated braid formed by the braiding apparatus of the present invention. 
       FIG. 12  is an expansive perspective view of a cross-section of the perforated braid produced by the braiding apparatus of the present invention. 
       FIG. 13  is a plane view showing the perforated braid produced by the braiding apparatus according to the present invention. 
       FIG. 14  is a plane view showing an arrangement of eight coupling holes on the carrier guide plate for the braiding apparatus according to another embodiment of the present invention. 
       FIG. 15  is a plane view showing an arrangement of sixteen coupling holes on the carrier guide plate for the braiding apparatus according to another embodiment of the present invention. 
       FIG. 16  is a plane view showing an arrangement of sixteen coupling holes on the carrier guide plate for the braiding apparatus according to another embodiment of the present invention for producing a perforate braid with a rectangular cross-section. 
       FIG. 17  is an expansion perspective view of the perforated braid with a rectangular cross-section produced by the carrier guide plate of FIG.  16 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   In order to achieve the above-mentioned objectives, the preferred embodiments of the present invention will now be described accompany with drawings. 
   A braid generally comprises multiple core yarns disposed at the center and a common coating braided with a plurality of yarns on the circumferential multiple interior core yarns. 
   Referring to  FIGS. 11 and 12 , the structure of perforated braid according to the present invention consists dual core yarns  1 ,  1 ′ combined together with the common exterior braid  3 . The common exterior braid  3  has a plurality of holes  4 ,  4 ′ with constant intervals. A binding means or knot is provided, then a pair of braids is passed through the perforations. 
   Referring to  FIGS. 2  to  5 , a typical braiding apparatus includes a carrier guide plate  10  formed with carrier contours  14 ,  14 ′, a base plate  40  located at a certain gap from a lower portion of guide plate  10 , a plurality of carriers  20  moving along the carrier contours  14 ,  14 ′ formed on the carrier guide plate  10 , a plurality of feed gears  30  rotatably mounted on the base plate  40  corresponding to the carriers  20  and a feed disc  31  fixed to the upper end of the shaft  30   a  of the feed gear  30  and interposed at a carrier base  21  mounted to the lower end of the carrier  20 . Herein, when the feed gear  30  is rotated, the feed disc  31  is repetitively inserted into and removed from the carrier base  21  of the carrier  20 . Thus, the carrier  20  is repetitively rotated along the carrier contours  14 ,  14 ′, thereby enabling the braiding of the braid  3 . 
   To produce a perforated braid with dual core yarns, the braiding apparatus according to the preferred embodiment of the present invention is constructed as follows: The carrier guide plate  10  provides two separated core yarn holes  12 ,  12 ′ located at the center of each half of the carrier guide plate  10 , two sets of coupling holes  13 ,  13 ′ arranged circumferentially around each core yarn hole  12 ,  12 ′, two sets of carrier contours  14 ,  14 ′ formed in zigzag patterns with a certain depth along the circumferential coupling holes  13 ,  13 ′ and four slots  15 ,  15 ′ diposed at the contacting portion of the carrier contours at a certain distance from the center of the carrier guide plate  10 . Each carrier contour  14 ,  14 ′ is separately formed inward and outward of the coupling holes  13 ,  13 ′ to alternately cross each other. 
   Each feed gear  30  is mounted on the upper portion of the base plate  40  so that the circumferential feed disc  31  exposed above the coupling holes  13 ,  13 ′ of the carrier guide plate  10  is interposed at the carrier base  21  located at the lower end of carrier  20 . 
   Additionally, the carrier contour changers  50 ,  50 ′ disposed under the carrier guide plate  10  are inserted through the slots  15 ,  15 ′ of the carrier guide plate  10 . A pair of change rods  51 ,  51 ′ is inserted to these carrier contour changers  50 ,  50 ′ so that the carrier contours  14 ,  14 ′ can be crossed and separated repetitively at the crossing portion. 
   Moreover, a plurality of actuators  42 ,  42 ′ having operating rods  41 ,  41 ′ is mounted perpendicularly under the base plate  40 . The actuators  42 ,  42 ′ enable operation of the carrier contour changers  50 ,  50 ′ via links  43 , operating rods  41 ,  41 ′ and change rods  51 ,  51 ′ repetitively crossing and separating the carrier contours  14 ,  14 ′. 
   As shown in  FIGS. 4 and 5 , a pair of carrier contour changers  50 ,  50 ′ connected to each end of change rods  51 ,  51 ′ is constructed on each operating frame  52 ,  52 ′. The carrier contour changers  50 ,  50 ′ are crossed and coupled to each other. A pair of change block assemblies  90 ,  90 ′ are coupled on the operating frames  52 ,  52 ′ by fixing pins  53 . 
   As shown in  FIG. 5 , the change block assembly  90  includes a main block  60 , an intermediate cross block  70  and an inner split block  80 . The main block  60  comprises a longitudinal slot  61  formed at lower center of both lateral surfaces for transversely penetrating through the block, a pair of vertical coupling holes  67 ,  67 ′ formed at opposite ends and perforated at a right angle, a protruded portion  62  formed at the center between both coupling holes  67 ,  67 ′ and a concave recess  63 , a vertical split rising opening  65  forming a rectangular shape at the center of the concave recess  63  and both side projections  64 ,  64 ′ constituting the protruded portion  62  and cross rising openings  66  formed a triangular shape at opposite sides of the split rising openings  65 . The intermediate cross block  70  comprises an inclined slot  71  penetrating through the block, a vertical inserting opening  72  formed at the center and a pair of cross guide flaps  73 ,  73 ′ formed at opposite sides of the vertical insertion opening  72  for mating with the cross rising opening  66  of the main block  60 . The inner split block  80  comprises a declined slot  81  formed at lateral surface in the opposite direction of the inclined slot  71  of the intermediate cross block  70  and a split guide flap  82  formed at the center of upper portion to mate with the split rising opening  65  of the main block. 
   Herein, a pair of fixing pins  53  inserted from one side of operating frame  52  is sequentially passed through the longitudinal slot  61  of the main block  60 , the inclined slot  71  of intermediate cross block  70  and the declined slot  81  of the inner split block  80 , thereby coupling the change block assembly  90  to the operating frame  52 . 
   Additionally, an inner lateral surface of the concave recess  63  of the main block  60  has a convex shape protruded inwardly and an outer lateral surface of the cross guide flaps  73 ,  73 ′ of the intermediate cross block  70  and both lateral faces of the split guide flaps  82  of the inner split block  80  has an inwardly recessed concave shape. In this manner, the carrier base  21  is able to move smoothly along the carrier contours  14 ,  14 ′. 
   In the thusly constructed braiding apparatus, a perforated braid with a different number of braided yarns  2 ,  2 ′ and different shape can be produced depending on a number of the coupling holes  13 ,  13 ′ formed on the carrier guide plate  10 , shape of the carrier contours  14 ,  14 ′ corresponding to the coupling holes  13 ,  13 ′ and a number of the carriers  20  mounted on the feed disc  31 . 
   For instance, the coupling holes  13 ,  13 ′ radially formed circumferential each core yarn hole  12 ,  12 ′ are able to be arranged in the manner that: for producing a perforated braid having sixteen strands of braided yarns  2 ,  2 ′, total of eight coupling holes  13 ,  13 ′ and corresponding carrier contours  14 ,  14 ′ are radially formed circumferential each core yarn hole  12 ,  12 ′. Thus, eight feed discs  31  and sixteen carriers  20  are arranged at the coupling holes  13 ,  13 ′ for circulating around the carrier contours  14 ,  14 ′. 
   For producing a perforated braid having twenty-four strands of braided yarns  2 ,  2 ′, total of twelve coupling holes  13 ,  13 ′ and corresponding carrier contours  14 ,  14 ′ are radially formed circumferential each core yarn hole  12 ,  12 ′. The twelve feed discs  31  and twenty-four carriers  20  are arranged at the coupling holes  13 ,  13 ′ for circulating around the carrier contours  14 ,  14 ′. 
   When a total of sixteen coupling holes  13 ,  13 ′ and the corresponding carrier contours  14 ,  14 ′ are radially formed circumferential each core yarn hole  12 ,  12 ′ and sixteen feed discs  31  and thirty two carriers  20  are arranged at the coupling holes  13 ,  13 ′ for circulating around the carrier contours  14 ,  14 ′, a perforated braid having thirty-two strands of braided yarns  2 ,  2 ′ could be produced. 
   Further, a total of twenty coupling holes  13 ,  13 ′ and the corresponding carrier contours  14 ,  14 ′ are formed radially circumferential each core yarn hole  12 ,  12 ′ and twenty feed discs  31  and forty carriers  20  are arranged at the coupling holes  13 ,  13 ′ for circulating around the carrier contours  14 ,  14 ′, another perforated braid having forty strands of braided yarns  2 ,  2 ′ is produced. 
   The perforated braid having multiple strands of braided yarns  2 ,  2 ′ produced by the plurality of feed discs  31  and carriers  20  can be applied depending on the purpose or usage of perforated braids. For instance, forty eight or fifty six strands of perforated braids or the like can be produced as well as the above-described sixteen, twenty four, twenty six, thirty two or forty strands of perforated braids. 
   Hereinafter, a process for producing the perforated braid by using the braiding apparatus of the present invention will describe in detail with reference to the accompanying drawings. 
   First, according to the preferred embodiment of the present invention, a structure of braiding apparatus for producing a perforated braid comprised of twenty-four strands of braided yarns will be described with reference to the accompanying drawings. 
   As shown in  FIG. 2 , a pair of core yarn holes  12 ,  12 ′ is formed at each center of half carrier guide plate  10 . Each core yarn  1 ,  1 ′ is supplied through each of the core yarn holes  12 ,  12 ′ under the guide plate  10 . A plurality of coupling holes  13 ,  13 ′ is circumferentially formed around the core yarn holes  12 ,  12 ′. 
   The carrier contours  14 ,  14 ′ having a certain depth on the circumferential coupling holes  13 ,  13 ′ are paths for traveling the carrier base  21  which is disposed at lower part of the carrier  20 . The carrier contours  14 ,  14 ′ are continuously connected along the contour of the coupling holes  13 ,  13 ′ in a zigzag pattern. The zigzag pattern of inner carrier contour  14 ′ is formed in the opposite side of the outer carrier contour  14 , whereby the two carrier contours  14 ,  14 ′ are repetitively crossed with each other. 
   A feed disc  31  is located above the carrier guide plate  10  to interpose the carrier base  21 . The feed disc  31  is coupled to the upper end of the shaft  30   a  of the feed gear  30  fitted to the coupling holes  13 ,  13 ′ and rotated by rotation of feed gear  30 . When the feed disc  31  is rotated by feed gear  30 , the carrier base  21  and the carrier  20  travels along the carrier contours  14 ,  14 ′. 
   Herein, a base plate  40  is located at a certain interval under the carrier guide plate  10 . The feed gear  30  is rotatably mounted on the base plate  40  to match with the coupling holes  13 ,  13 ′ of the carrier guide plate  10 . Additionally, two actuators  42 ,  42 ′ are mounted under the base plate  40 . 
   The actuators  42 ,  42 ′ operate carrier contour changers  50 ,  50 ′, which are attached under the carrier guide plate  10 . When operating rods  41 ,  41 ′ move forward or backward according to the actuators  42 ,  42 ′, the movement of operating rods  41 ,  41 ′ is transmitted to the change rods  51 ,  51 ′ through links  43 . Subsequently, the carrier contour changers  50 ,  50 ′ connected to the change rods  51 ,  51 ′ operates the change block assemblies  90 ,  90 ′. Hence, each carrier  20  is separately crossing with each other at a crossing point to switch the traveling path of the carrier contours  14 ,  14 ′. At this time, the carrier  20  rotates on the carrier guide plate  10  while traveling along the carrier contours  14 ,  14 ′. 
   As shown in  FIG. 3 , the feed gear  30  integrally attached to a shaft  30   a  is mounted to the base plate  40  by a fixing axis  32  and nut  34 . The feed gear  30  is rotatably mounted between the carrier guide plate  10  and the base plate  40  by the fixing axis  32  and a pair of bearings  36 . When a power is transmitted through the shaft  30   a  by rotating of the feed gear  30 , the carrier base  21  is rotated as the rotating of the feed disc  31  mounted on the upper end of the shaft  30   a.    
   At the same time, when the actuators  42 ,  42 ′ operate as described above, the operating force is transmitted to the carrier contour changers  50 ,  50 ′ through the operating rods  41 ,  41 ′, the links  43  and the change rods  51 ,  51 ′. Thus, two carrier contour changers  50 ,  50 ′ operate the change block assemblies  90 ,  90 ′ that are inserted into the square slots  15 ,  15 ′. At this time, a guide projection  21   a  disposed at the carrier base  21  is installed in the carrier contours  14 ,  14 ′. As the rotation of the feed gear  30 , the feed disc  31  disposed above carrier guide plate  10  rotates the carriers  20  to travel along the carrier contours  14 ,  14 ′ of the carrier guide plate  10 . 
   In this manner, the plurality of yarns supplied through the core yarn holes  12 ,  12 ′ are braided, while a plurality of carriers  20  is rotated and traveled along the carrier contours  14 ,  14 ′. 
   Herein, the actuators  42 ,  42 ′ can be applied a cylindrical type as shown in the drawing or other operating means that can be performed a linear motion by electronic or mechanical means such as a solenoid or cam driving device. 
   As shown in  FIG. 4 , a pair of change block assemblies  90 ,  90 ′ installed inside the operating frames  52 ,  52 ′ is provided for crossing or separating operations of the plurality of carriers  20  along the carrier contours  14 ,  14 ′. The relative positions or tracks of the carrier contours  14 ,  14 ′ varies depending on the location of the fixing pins  53 ,  53 ′ mounted on the operating frames  52 ,  52 ′. The intermediate cross blocks  70  and inner split blocks  80  being disposed in the change block assemblies  90 ,  90 ′ move upward or downward depending on the position of fixing pins  53 ′,  53 ′. 
   Herein, a pair of operating frames  52 ,  52 ′ is arranged to cross each other. At this point, each position of fixing pins  53 ,  53 ′ mounted on the operating frames  52 ,  52 ′ is arranged to locate the same distance below the carrier guide plate  10 . Either one operating frame  52 , which is positioned above, has a fixing pin  53  at the center of the thickness of the operating frame  52 . Other operating frame  52 ′, which is positioned below, has formed a raised position of fixing pin  53 ′ to locate same position to the upper operating frame  52 . 
   Therefore, the height of change block assemblies  90 ,  90 ′ mounted inside the operating frames  52 ,  52 ′ in the cross arrangement is same with each other. Thereby, the change block assemblies  90 ,  90 ′ are inserted to the same level of the square slots  15 ,  15 ′ formed on the carrier guide plate  10 , and to match the same depth of the carrier contours  14 ,  14 ′. 
   As shown in  FIG. 5 , the change block assembly  90  disposed inside the operating frame  52  comprises a main block  60 , an intermediate cross block  70  and an inner split block  80 . 
   The main block  60  is constructed in such a manner that; a longitudinal slot  61  is formed for inserting the fixing pin  53  though the operating frame  52 , a pair of fastener mounting holes  67 ,  67 ′ are formed at opposite flat surfaces, and a protruded portion  62  is formed at the center of the block with a pair of arc-shaped projections  64 ,  64 ′ at both end-sides. Additionally, a concave recess  63  is formed in the middle of the protruded portion  62  with vertical split opening  65  and a triangular shaped cross opening  66 . 
   Next, the intermediate cross block  70  is constructed in such a manner that an inclined slot  71  is formed on a lateral surface and a vertical insertion opening  72  is formed at the center of the upper portion. Additionally, a pair of cross guide flaps  73 ,  73 ′ is formed at both sides of the upper surface for inserting to the cross opening  66  of the main block  60 . 
   The inner split block  80  is constructed in such a manner that: a declined slot  81  is formed at a lateral surface in the opposite direction of the inclined slot  71  of the cross block  70  and a split guide flap  82  for inserting to the split opening  65  of the main block  60  formed at the center of the upper portion. The split guide flap  82  is inserted to the insertion opening  72  of the intermediate cross block  70 . 
   In the assembling process, the fixing pins  53  are inserted from the lateral side of the operating frames  52  sequentially passing through the longitudinal slot  61  of the main block  60 , the inclined slot  71  of the intermediate cross block  70  and the declined slot  81  of the inner split block  80 . The operating frame  52  moves forward or backward by the actuators  42  through the transmitting mechanism, the relative position of the inclined slot  71  and declined slot  81  to the fixing pin  53  is varied. Accordingly, the intermediate cross block  70  and the inner split block  80  operationally coupled to the fixing pin  53  through the inclined slot  71  and declined slot  81  to ascend or descend in directions from each other. 
   As shown in  FIGS. 6   a  and  6   b , the upper end of the change block assembly  90  is mounted to the operating frame  52  by inserting from the underneath carrier guide plate  10  through the square opening  15 . In this state, when the operating frame  52  moves forward unilaterally, the intermediate cross block  70  ascends and the inner split block  80  descends. 
   Since the carrier contours  14 ,  14 ′ move to cross with each other, the carrier  20  is induced to move continuously without splitting the carrier contours  14 ,  14 ′. Hence, as described above, one strand of braid is produced by the carrier  20  traveling along the entire track of the carrier contours  14 ,  14 ′. 
   As shown in  FIGS. 7   a  and  7   b , the upper end of change block assembly  90  is inserted from underneath carrier guide plate  10  through the square opening  15 . When the operating frames  52  moves backward unilaterally, the intermediate cross block  70  descends and the inner split block  80  ascends. 
   In this case, since the carrier contours  14 ,  14 ′ move to be separated from each other, this operation induces the carrier  20  partially moving without crossing the carrier contours  14 ,  14 ′. Hence, the carrier  20  traveling produces two strands of braid along the track of the carrier contours  14 ,  14 ′. 
   Referring to  FIG. 8 , the twelve feed discs  31  are located on the upper portion carrier guide plate  10  and twenty-four carriers  20  are mounted on the feed discs  31 . At this point, since the feed gears  30  are engaged with each other, one feed disc  31  rotates while another adjacent feed gear  30  rotates reverse. As the result, one group of carriers proceeds in the forward direction by rotation of feed disc  31  and another group of carriers proceed in the reverse direction by reverse rotation of feed disc  31 . 
   For example, when the carrier number one to carrier number twenty proceed clockwise, the carrier letter A to carriers number twenty L proceed counterclockwise. 
   According to the proceeding directions as described above, the braided yarns  2 ,  2 ′ drawn from each carriers  20  are crossed each other at the crossing sections, a braid with circular section is braided. 
   As sown in  FIG. 9 , the pair of carrier contour changers  50 ,  50 ′ operates the change block assemblies  90 ,  90 ′ in the upward and downward directions for crossing operation and in the left and right directions for splitting operation by providing two carrier contours  14 ,  14 ′. Thus, one strand of braid having dual core yarns is braided with the plurality of carriers  20  by proceeding in the forward or backward direction along the entire track of the carrier contours  14 ,  14 ′. 
   As shown in  FIG. 10 , the traveling of the carriers is shown on the carrier guide plate when the two strands of carriers are braided. 
   The change block assemblies  90 ,  90 ′ operate in upward and downward directions for splitting operation and in leftward and rightward directions for crossing operation by the carrier contour changers  50 ,  50 ′. Subsequently, four carrier contours  14 ,  14 ′ are formed to produce two strands of braid having dual core yarns braided by the plurality of carriers  20  proceeding in forward or backward directions along the track of the carrier contours  14 ,  14 ′. 
   Thus, the perforated braid of the present invention is completed through the crossing and splitting operation by the carrier contour changers  50 ,  50 ′. 
   Herein, the size of perforation is controllable according to controlling the operating time of splitting and crossing of the carrier changers  50 ,  50 ′. If the operation of splitting time were prolonged, the size of perforation would be larger. Therefore, the size of perforation is proportional to the elapsed time of splitting operation. 
   Additionally, the interval of perforation is determined according to the cycle or alteration of the carrier contour changers  50 ,  50 ′ for crossing and splitting operation. That is, it is determined how often the crossing and splitting operations are repeated. At this point, one strand of braid is formed by the crossing operation while two strands of braid are being alternatively formed by the splitting operation. 
   Typically, the carrier contour changers  50 ,  50 ′ are operated by a general delay circuit or control circuit, so a detailed description thereof will be omitted. 
   As shown in  FIG. 11 , an end portion of perforated braid is produced by repeating the braiding with one strand and two strands of braid. The perforated braid  3  comprises dual interior core yarns  1 ,  1 ′ combined in parallel, a common exterior braid  3  with a plurality of perforations  4 ,  4 ′. The perforations  4 ,  4 ′ on the common exterior braid  3  are arranged with constant intervals. A binding means or knot is provided for combining a pair of braids by passing through the perforations each other. 
   As shown in  FIG. 12 , one strand of braid  3  comprises dual interior core yarns  1  and  1 ′, which are combined in parallel and a common exterior braid  2 . In case of braiding two strands of braids, dual interior core yarns  1  and  1 ′ may be separated to locate each strand, respectively. 
   As shown in  FIG. 13 , the size and interval of perforations  4 ,  4 ′ of the perforated braid  3  can be varied depending on the purpose of usages. 
   Referring to  FIG. 14 , a carrier guide plate applied to sixteen carriers has the coupling holes  13 ,  13 ′ radially formed circumferential each core yarn  12 ,  12 ′. In this case a total of eight coupling holes  13 ,  13 ′ and corresponding carrier contours  14 ,  14 ′ are formed on the carrier guide plate  10 . It also provides eight feed-discs  31  and sixteen carriers  20  located at the coupling holes  13 ,  13 ′. Therefore, a perforated braid with sixteen strands of braided yarns  2 ,  2 ′ is produced by circulating around the carrier contours  14 ,  14 ′. It is appreciated that the perforated braid produced by the sixteen strands of braided yarns has the same shape as the perforated braid produced by twenty-four strands of braided yarns  2 ,  2 ′. But, it has relatively smaller number of strands of braided yarns  2 ,  2 ′. 
   Referring to  FIG. 15 , a carrier guide plate applied to thirty-two carriers comprises the coupling holes  13 ,  13 ′ radially formed circumferential each core yarns  12 ,  12 ′ on the carrier guide plate  10 . In this case, a total of sixteen coupling holes  13 ,  13 ′ and corresponding carrier contours  14 ,  14 ′ are formed on the carrier guide plate  10 . It also provides sixteen feed-discs  31  and thirty-two carriers  20  located at the coupling holes  13  and  13 ′. Therefore, a perforated braid with thirty-two strands of braided yarns  2 ,  2 ′ is produced by circulating around the carrier contours  14 ,  14 ′. 
   As shown in  FIG. 16 , a carrier guide plate  10  for producing a perforated braid with a rectangular cross-section comprises four coupling holes  13 ,  13 ′ circumferentially formed around each core yarn holes  12 ,  12 ′, and a pair of additional coupling holes  13 ,  13 ′ formed parallel to endmost left and right coupling holes  13 ,  13 ′. Therefore, the perforated braid with twenty-six strands of braided yarns  2 ,  2 ′ can be produced by twenty-six carriers  20  traveling along the carrier contours  14 ,  14 ′ formed by total of twelve coupling holes  13 ,  13 ′. 
   Referring to  FIG. 17 , a perforated braid with a rectangular cross-section being produced by aforementioned carrier guide plate comprises dual core yarns  1 ,  1 ′ bound parallel apart by a certain distant, and a common exterior braid  3 . The common exterior braid  3  has a plurality of perforations  4 ,  4 ′ with constant intervals. The perforated braid with rectangular cross-section is suitable to use for flat-type straps such as soccer shoe straps. When the perforated braid with rectangular cross-section is applied to the soccer shoes, it is possible to reduce the chances of loosening the strap during exercising. Because of the rectangular cross-section, it will increase the binding force on the strap. 
   Hereinafter, a process for braiding the yarns  2 ,  2 ′ by the braiding apparatus of the present invention is described according to the aforementioned explanations. 
   The multiple braided yarns  2 ,  2 ′ are wound on a plurality of carriers  20  which are engaged with the feed discs  31 . The core yarns  1 ,  1 ′ drawn from underneath the carrier guide plate  10  are inserted into the core yarn holes  12 ,  12 ′. 
   At this point, a plurality of feed gears  30  driven by feed motor (not shown) is arranged so that a group of feed gears  30  rotate clockwise. Simultaneously, the other group of feed gears  30  rotates counterclockwise at a constant speed. 
   As two groups of the feed gears  30  are rotating simultaneously in the opposite directions, the feed discs  31  mounted on top of the shaft  30   a  are also rotating in two groups of directions. The carrier base  21  disposed lower part of the carriers  20  engages with the feed discs  31  to travel along the carrier contours  14 ,  14 ′. The rotation of the feed discs  31  causes the carriers  20  to rotate. Thereby the carriers  20  are continuously traveling along the carrier contours  14  and  14 ′. 
   The multiple yarns  2 ,  2 ′ are braided for surrounding the outer surface of the core yarns  1 ,  1 ′ while the carriers  20  are traveling and rotating. At this point, the carriers  20  are crossed each other at the crossing sections of the carrier contours  14 ,  14 ′ for producing braiding yarns  2 ,  2 ′. The thusly produced braid is wound on the winding rollers (not shown), which are rotating with same braiding speed. 
   The process for braiding one strand of braid is described as follows. 
   When the pair of actuator  42 ,  42 ′ operates corresponding carrier contour changer  50 ,  50 ′ forward or rearward, each intermediate cross block  70  and inner split blocks  80  in each change block assembly  90 ,  90 ′ moves ascending or descending, respectively. For instance, if the carrier contour changer  50  moves forward direction, the intermediate cross block  70  descends and the inner split blocks  80  ascends. If the carrier contour changer  50  moves rearward, the intermediate cross block  70  ascends and the inner split block  80  descends, due to the disposition of the fixing pin  53 . The crossed carrier contour changer  50 ′ operates in the same manner as the intermediate cross block  70  and inner split blocks  80  of the change block assembly  90 ′ ascending or descending respectively depending on the location of the fixing pin  53 ′. Through this operation, two carrier contours  14 ,  14 ′ are provided two tracks of forward and backward traveling for two groups of carriers  20 . 
   At this moment, one group of carriers  20 , the carrier numbers one to twelve move along the carrier contours  14 ,  14 ′ in the counterclockwise and the other group of carriers  20 , for example the carrier letters A to L move along the carrier contours  14 ,  14 ′ clockwise. 
   Thusly, the multiple yarns are braided while they are moving in forward and backward directions to form one strand of braid composed of twenty-four strands of yarns having dual core yarns  1 ,  1 ′. 
   For forming perforations at a certain section during the process of braiding one strand of braid, the core yarns  1 ,  1 ′ must be braided and separated with each other to form two braids having each core yarn  1 ,  1 ′. At this point, the carrier contour changers  50 ,  50 ′ are operated in the opposite direction by the actuators  42  and  42 ′ disposed underneath the base plate  40 . Accordingly, the left and right sides of two carrier contours  14 ,  14 ′ are provided for four carrier contours for the splitting operation. 
   For example, one strand of braid is produced that one group of the carriers (carrier number one, two, three, ten, eleven and twelve among the multiple carriers) rotates around the core yarn hole  12  while other group of the carriers (carrier number or letter A, B, C, D, K, and L among the multiple carriers) reverse rotate around the core yarn hole  12 . 
   Meanwhile, other side strand of braid is produced that one group of the carriers (carrier number four, five, six, seven, eight and nine among the plurality of carriers) rotates around the core yarn hole  12 ′, while another group of the carriers (carrier number or letter e, f, g, h, I and j among the plurality of carriers) rotate in a reverse direction around the core yarn hole  12 ′. 
   Hence, two carrier contours  14 ,  14 ′ are provided two tracks of circular-shaped zigzag pattern for splitting and forming the braid. Thusly, the braid having two strands of braid with twelve strands of yarns  2 ,  2 ′ is produced thru this device. 
   In this manner, the two strands of braided section is formed a perforation section. When a desired size of perforation  4 ,  4 ′ is produced by the two strands of braid, the carrier contour changers  50 ,  50 ′ are returned to the original position. 
   The path of carrier contours  14 ,  14 ′ are alternatively switched each other by the carrier contour changers  50 ,  50 ′. Thus, one strand or two strands of braid having perforations  4 ,  4 ′ with constant intervals are continuously produced by alternative splitting and braiding operation. 
   With thusly produced braid of the present invention, it is possible to bind the braids without a knot by piercing one braid passing through the perforations  4 ,  4 ′ with each other. Subsequently, the binding is comfortable and discreet to apply excessive force because it is not easily untied nor loosened. 
   On the other hand, if it were necessary to untie the binding portion, it would be untied easily by releasing the braid retreating from the perforations  4 ,  4 ′. Thus, it is easily and conveniently tie or releasing the binding portion. 
   If the perforated braid of the present invention is used for shoes straps, the problem of loosening or untie straps during an exercise can be solved due to the new binding device. Also, the strap length can be remarkably reduced to fit on the shoes with proper binding force. Consequently, the overall weight of the shoes can be reduced and the feasibility can be maximized. 
   If the perforated braid of the present invention is further applied to the fishing nets or mainlines, a branch line would be connected through perforations, which are formed with constant intervals. Due to the binding of perforations and branch lines, the displacement problem of the fishing nets can be solved. 
   As described above, the perforated braid of the present invention is applicable to various purposes by changing in size and intervals of the perforations. 
   The perforated braid with dual core yarns and the braiding apparatus according to the present invention provides firm binding as well as easy untie binding device because of a binding means without knit. Particularly, the perforated braid, when applied to fishing nets or fishing lines, provides easy binding means so that the branch lines are binding through the perforations with same intervals. The new binding means is also solves shifting problems of the branch lines. If the perforated braid were applied to the shoe straps, it could solve the loosening problem during exercise. It is also able to reduce the length of the shoe straps and maximize the flexibility. Further, the size and interval of the perforation can be changed depending on the various usages. 
   The present invention has been described in an illustrative manner and it is to be understood that the terminology used is intended to be in the nature of description rather than of limitation. Many modifications and variations of the present invention are possible in light of the above teachings. Therefore, it is to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.