Patent Publication Number: US-2005126036-A1

Title: Sole structure with complex waterproof and gas-permeable material and manufacturing method thereof

Description:
BACKGROUND OF THE INVENTION  
      The present invention is related to a waterproof and gas-permeable sole structure and a manufacturing method thereof, and more particularly to an improved sole structure which overcomes the problem that the vapor tarries between the large substrate and the middle substrate (or insole) of the conventional gas-permeable shoe.  
      The conventional waterproof gas-permeable film such as Gore-Tex film (so-called century fabric) is composed of two kinds of unique polymers. One of the polymers is a nearly thermoplastic polyurethane (TPU) material which provides high stiffness. The other is ePTFE which provides waterproof and gas-permeable effect. Nine billion micro-voids are distributed over each square inch area of such material. The size of such void is two hundred millionth the size of liquid water molecule. However, the size of such void is seven hundred times the size of vapor. Therefore, the water molecule cannot pass through the voids, while the vapor is permitted to be exhausted through the voids. The waterproof gas-permeable film such as Gore-Tex can be attached to inner side of nylon and other fabric for making clothes, shoes, gloves, etc. to achieve windproof, waterproof and gas-permeable characteristics. A user wearing such clothes or shoes can keep dry, warm and comfortable.  
       FIG. 1  shows that the waterproof gas-permeable film such as Gore-Tex is adhered to inner side of a sole for waterproof effect and exhaustion of vapor to keep a user&#39;s feet dry. The sole  10  includes a large substrate  11 , a middle substrate  12  connected on the large substrate  11  and an insole  13  overlaid on the middle substrate  12 . The large substrate  11  is generally made of thermoplastic rubber (TPR) material which is cheaper. Alternatively, the large substrate  11  can be made of TPU or PVC. In the conventional measure, the Gore-Tex has a characteristic closer to that of TPU so that the Gore-Tex can hardly combined with TPR material. Therefore, in manufacturing, the more expensive waterproof and gas-permeable film  40  is adhered between the large substrate  11  and the middle substrate  12  to prevent the water from entering the middle substrate  12  and the insole  13 . As known by those skilled in this field, in actual use, although the vapor is isolated from the inner layer of the shoe, the water still often remains between the large substrate  11  and the middle substrate  12  in the positions as shown by the arrows of  FIG. 1 . This makes a user feel uncomfortable. Moreover, in use of the shoe, the sole will bear great bending force and impact. Therefore, it is quite hard to combine the materials with each other with glue.  
      In the above structure, the waterproof and gas-permeable film  40  is adhered to the sole  10  to isolation of water and exhaustion of vapor of a user&#39;s feet. However, such structure fails to overcome the problem that the water tarries between the large substrate  11  and the middle substrate  12 . The melting point of the large substrate  11  is about 180° C. The melting point of the waterproof and gas-permeable film  40  is about 120° C. In addition, these two materials are incompatible with each other. As a result, during the molding procedure, when filling the material of higher temperature into the sole, the waterproof and gas-permeable film  40  is often previously molten or unexpectedly damaged. Therefore, it is hard to associate the waterproof and gas-permeable film  40  with the large substrate  11 . This obstructs the waterproof and gas-permeable film  40  from successfully associating with the large substrate  11 .  
     SUMMARY OF THE INVENTION  
      It is therefore a primary object of the present invention to provide a sole structure with complex waterproof and gas-permeable material and a manufacturing method thereof. The sole provides waterproof and gas-permeable effect to prevent water from tarrying between the large substrate and middle substrate of the sole. A plane blank having a through with a pattern of an array is provided. A waterproof and gas-permeable film made of a material identical to or compatible with the material of the plane blank is combined with the plane blank to cover the through hole. The plane blank with the film is located in a predetermined position inside a sole mold. Then a molten plastic material is filled into the mold to associate the plane blank and the film with the plastic material to form an integral sole.  
      According to the above object, the sole structure includes a large substrate and a middle substrate overlaid on an inner face of the large substrate. The plane blank combined with the waterproof and gas-permeable film is disposed in a predetermined position on inner face of the large substrate. The water on outer side of the large substrate is isolated and prevented from getting into the shoe through the through hole of the large substrate. However, the air can pass through the waterproof and gas-permeable film into the shoe to achieve gas-permeable and humidity proof effect. The area of the plane blank is larger than that of the film. The molten plastic material at high temperature is fused with the peripheral section of the plane blank. However, by means of a mold core, the plastic material is isolated from the film without contacting and damaging the film.  
      In the above structure, multiple fixing holes are formed along the peripheries of the plane blank. When the plastic material is filled into the mold, the plastic material can fill into the fixing holes to form a key structure for firmly associating the plane blank with the plastic material.  
      In addition, a sheet material such as a mesh tissue sheet or porous sheet with high stiffness (such as TPU sheet) is associated with at least one face of the film to reinforce the film and prolong using life of the film.  
      The present invention can be best understood through the following description and accompanying drawings wherein:  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a sectional view of the sole of a conventional gas-permeable shoe;  
       FIG. 2  is a perspective exploded view of the sole of the gas-permeable shoe of the present invention;  
       FIG. 3  is a sectional view according to  FIG. 2 ;  
       FIG. 4  is a sectional assembled view according to  FIG. 3 ;  
       FIG. 5  is a bottom view according to  FIG. 4 ;  
       FIG. 6  is a perspective exploded view of the plane blank, sheet material and film of the present invention, showing the connection relationship thereof;  
       FIG. 6A  is a sectional assembled view according to  FIG. 6 , showing that the assembly of the plane blank, sheet material and the film is placed in a mold for molding the large substrate of the sole, in which the plastic material is not yet filled into the mold;  
       FIG. 6B  is a view according to  FIG. 6A , in which the plastic material is filled into the mold;  
       FIG. 7  is a perspective exploded view of the plane blank, sheet material and film of the present invention, showing another connection relationship thereof;  
       FIG. 7A  is a perspective exploded view showing that both the upper and lower faces of the film are associated with sheet materials;  
       FIG. 8  is a sectional assembled view according to  FIG. 7 , showing that the assembly of  FIG. 7  is placed in a mold;  
       FIG. 8A  is an enlarged view of circled area A of  FIG. 8 ;  
       FIG. 9  is a sectional view according to  FIG. 8 , showing that the plastic material is filled into the mold; and  
       FIG. 9A  is an enlarged view of circled area A of  FIG. 9 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Please refer to  FIGS. 2 and 3 . The sole structure  10  with complex waterproof and gas-permeable material of the present invention includes a large substrate  11 . The large substrate  11  can be selectively made of any of TPR, PVC, TPU and the likes. A middle substrate  12  and/or an insole  13  are overlaid on the large substrate  11 . A predetermined section of inner face of the large substrate  11  is formed with through holes  14 ,  15  which can have any geometric profile. The through holes  14 ,  15  are arranged on front half, rear half or other section of the large substrate  11 .  
      A plane blank  16  combined with waterproof and gas-permeable film  40  is laid on the inner face  111  of the large substrate  11  to correspondingly cover the through holes  14 ,  15 . The plane blank  16  is made of a material identical to or compatible with the material of the waterproof and gas-permeable film  40 . The plane blank  16  is formed with an array-type through hole  17  corresponding to the through hole  14  or  15  of the large substrate. In this embodiment, the array-type through hole  17  has an array of multiple oblique slats arranged as a blind. Such array prevents alien articles from directly getting into the shoe through the through hole  17 . The film  40  is fixedly combined with the plane blank  16  by means of pressing, high frequency or ultrasonic wave. The film  40  at least covers the through hole  17  of the plane blank  16 . In principle, the area of the plane blank  16  is larger than the area of the film  40 . In a preferred embodiment, a sheet material  22  such as a mesh tissue sheet or reinforcing sheet made of stiffer material (such as TPU sheet) is associated with at least one surface of the film  40 . The sheet material  22  is attached to the film  40 . In another embodiment, the position relationship between the film  40  and the sheet material  22  and the number thereof are exchangeable and variable. In other words, the sheet material  22  can be arranged between the large substrate  11  and the film  40  (not shown) or between the film  40  and the middle substrate  12 . Alternatively, the sheet material  22  can be laid on both the upper and lower faces of the film  40 .  
       FIGS. 4 and 5  show the improved sole structure to which the plane blank  16  combined with the film  40  is applied. The water on outer face  112  of the large substrate  11  is isolated and prevented from getting into the through hole and tarrying between the inner side of the large substrate  11  and the middle substrate  12 . However, the vapor generated by the foot of a user is permitted to be exhausted from the large substrate  11  through the waterproof and gas-permeable film  40  at the through hole  17  of the plane blank  16 .  
      Referring to  FIG. 6 , the characteristic of the material of the large substrate  11  is different from that of the plane blank  16 . Therefore, they may be hard to associate with each other and incompatible. Accordingly, they are associated by a method including step (a), step (b) and step (c). In step (a), a sheet material  22  is laid between the plane blank  16  and the film  40  or on the inner face of the film  40 . The sheet material  22  can be stiffer sheet body such as TPU porous sheet densely formed with perforations or mesh tissue sheet. The stiffness of the TPU sheet can reinforce the plane blank  16  or film  40  to resist against intrusion or damage of rocks or other alien articles under the sole.  
      In step (b), the plane blank  16  associated with the film  40  and the sheet material  22  is located in a predetermined position inside a sole mold  20 . An isolating section or pile  21  is used to just cover the peripheral area of the through hole  17  of the blank  16 .  
      In step (c), a plastic (softened) material  30  is filled or placed into the mold  20  for integrally molding the large substrate  11 . The plastic material  30  is integrally associated with the periphery of the plane blank  16 . In the molding procedure, the plastic material  30  is isolated from the section of the film  40  corresponding to the through hole  17  by the mold  20 . Therefore, the plastic material  30  will not contact with or damage the section of the film  40 .  
      In order to solve the problem existing in the prior art that the water tends to tarry inside the large substrate  11  or between the large substrate  11  and the middle substrate  12 , the present invention has the following structural characteristics: 
          1. The large substrate  11  is formed with through holes  14 ,  15  in predetermined positions. A plane blank  16  combined with a film  40  is located on inner surface  111  of the large substrate  11  corresponding to the position of the through hole  14 .     2. The plane blank  16  is formed with an array-type through hole  17  corresponding to the through hole  14 . The film  40  at least covers the array-type through hole  17 , permitting the vapor of the foot to be exhausted from the large substrate through the through hole  17  of the film  40 . However, the water on outer side of the sole is isolated by the film  40  and prevented from getting into the shoe through the sole.     3. The area of the plane blank  16  should be larger than that of the film  40 . In step (b), the isolating section or pile  21  presses the plane blank  16  to cover the film  40 . Therefore, the filled high temperature plastic material  30  will flow to associate with the peripheral area of the plane blank  16 , while the plastic material  30  will not contact with and damage the section of the film  40  corresponding to the through hole  17 .        

       FIGS. 7, 7A ,  8  and  8 A show a partially modified embodiment of the present invention. In this embodiment, multiple fixing holes  18 ,  23  are formed along the periphery of the plane blank  16  or the sheet material  22 . When the plastic material  30  is filled into the mold  20 , the plastic material  30  can freely flow into the fixing holes  18 ,  23 . Accordingly, an insertion key structure can be formed between the plane blank  16  or sheet material  22  and the plastic material  30  as shown in  FIGS. 9 and 9 A. The periphery of the sheet material  22  can be also formed with an array fixing holes  23  as the plane blank  16 . The fixing holes  23  are aligned with the fixing holes  18  of the plane blank  16 . When filling the plastic material  30 , the plastic material  30  can be also well associated with the sheet material  22 . Accordingly, the large substrate  11 , plane blank  16 , film  40  and the sheet material  22  can be truly integrally adhered to each other.  FIG. 9A  shows that after the plastic material  30  enters the fixing holes  18 ,  23 , a part of the plastic material  301  will flow into the space between the bottom of the sheet material  22  and the mold to enclose or combine the plane blank  16 , film  40  and sheet material  22  into an integral body by means of the keys. When combined, due to high temperature, the film  40  may be partially molten. After molten, the formed voids is filled up with the plastic material  301 . This enhances the binding force for the integral body and prevents the parts of the integral body from detaching from each other when bent. It should be noted that the plane blank  16  can be previously formed with rough surface to enhance the binding force between the plane blank  16  and the plastic material  30 . For example, an interface activator or the like can be painted on the surface of the plane blank to clean and roughen the surface thereof. Alternatively, the surface of the plane blank  16  can be directly mechanically roughened to achieve better binding effect.  
      According to the above arrangement, the present invention can truly solve the problem existing in the conventional sole that the external water gets into shoe through the sole and tarries or accumulates on inner side of the large substrate  11  or between the large substrate  11  and the middle substrate  12 .  
      The above embodiments are only used to illustrate the present invention, not intended to limit the scope thereof. Many modifications of the above embodiments can be made without departing from the spirit of the present invention.