Patent Publication Number: US-2006000115-A1

Title: Method of making insole and insole made thereby

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a method of making an insole for shoes and more specifically, to the method of making an insole for shoe that has raised portions on the surface.  
      2. Description of the Related Art  
      An insole provides an elastic support to the sole of the user, enabling the user to walk comfortably. In order to enhance the elastic power and ventilation effect of an insole, the insole is made having raised portions protruding over the top surface. When the user pressed the sole on the raised portions of the insole, gaps are left in between the user&#39;s sole and the top surface of the insole for ventilation. An insole having raised portions may be molded from polymeric compound, foam material, rubber or the like. The mold has recessed portions in the cavity for forming raised portions on the surface of the insole. Usually, the insole molded integrally by this way has a bottom surface with recessed portions at areas corresponding to the raised portions of the top surface. When the insole is compressed, the raised portions tend to deform permanently after a long time of use of the insole, thereby reducing its elastic material property and ventilation effect.  
     SUMMARY OF THE INVENTION  
      It is the primary objective of the present invention to provide a method of making an insole, which is practical to make insoles that maintains a high elastic power and provides a satisfactory ventilation effect after a long time of use.  
      To achieve this objective of the present invention, the method of making an insole provided by the present invention comprises the steps of (a) providing a base sheet material made of a first compound, the base sheet material having a plurality of through holes through top and bottom sides thereof; (b) immersing the base sheet material in a fluid filling material prepared from a second compound to let the filling material fill up the through holes; (c) baking the base sheet material in a baking oven to cure the filling material; (d) splitting the base sheet material subject to a desired thickness; (e) bonding a fabric layer to a top surface of the base sheet material; (f) cutting the fabric layer bonded base sheet material thus obtained into a semi-finished insole with a predetermined shape; and (g) stamping the semi-finished insole to compact the base sheet material, for enabling the filling material to protrude over the top surface and a bottom surface of the base sheet material, thereby forming a plurality of raised portions at the fabric layer. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a flow chart according to a method of making an insole of the present invention.  
       FIG. 2  is a perspective view of a base material for insole according to the present invention.  
       FIG. 3  is a schematic drawing showing the filling material immersion procedure according to the present invention.  
       FIG. 4  is a sectional elevation of the base sheet material after filling material immersion according to the present invention.  
       FIG. 5  is a perspective view of the base sheet material after material splitting according to the present invention.  
       FIG. 6  is a perspective view of the base sheet material after fabric bonding according to the present invention.  
       FIG. 7  is a perspective view of a semi-finished insole obtained after cutting and baking procedure according to the present invention.  
       FIG. 8  is a perspective view of a finished insole made according to the present invention.  
       FIG. 9  is a sectional view in an enlarged scale of a part of the finished insole shown in  FIG. 8 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Referring to  FIG. 1 , a method of making an insole in accordance with the present invention includes the steps of (a) material preparation, (b) filling material immersion, (c) baking, (d) material splitting, (e) fabric bonding, (f) cutting and baking, and (g) stamping.  
      Referring to  FIG. 2 , a base sheet material  10  is provided during step (a) material preparation. The base sheet material  10  is molded from a polymeric compound, for example, EVA (Ethylene Vinyl Acetate), having a plurality of circular through holes  12  through the top and bottom sides thereof.  
      Referring to  FIGS. 3 and 4 , after step (a) material preparation, it proceeds to step (b) filling material immersion where the base sheet material  10  is immersed in a fluid filling material  14 , enabling the filling material  14  to fill in the through holes  12 . The filling material  14  is a different polymeric compound. According to this embodiment, the filling material  14  is latex. The filling material  14  is filled in the bottom die  16  of a mold  20  at first, and then the base sheet material  10  is put in the filling material  14  inside the bottom die  16 , and then a press  22  is operated to close the upper die  18  of the mold  20  on the bottom die  16 . When closing the upper die  18  on the bottom die  16 , the filling material  14  is forced to fill up the through holes  12  and to move over the top and bottom sides of the base sheet material  10 , and at the same time the base sheet material  10  is flattened. The flattened base sheet material  10  is kept in the mold  20  for several minutes to let the filling material  14  be hardened and fixedly positioned in the through holes  12 .  
      Thereafter, it proceeds to step (c) baking where the base sheet material  10  is removed from the mold  20  and then put in a baking oven and baked to cure the filling material  14 .  
      After step (c) baking, it proceeds to step (d) material splitting where the top and bottom layers are removed from the base sheet material  10  by splitting, thereby exposing the filling material  14  to the top and bottom side as shown in  FIG. 5 .  
      After step (d) material splitting, it proceeds to step (e) fabric bonding where a fabric layer  24  is covered on and bonded to the top side of the base sheet material  10  as shown in  FIG. 6 . The fabric layer  24  preferably has a color different from the color of the base sheet material  10  and the color of the filling material  14 , thereby producing a visual effect.  
      After step (e) fabric bonding, it proceeds to step (f) cutting and baking where the fabric layer  24  bonded base sheet material  10  is cut into semi-finished insoles  30  subject to the shape of the sole of a human being as shown in  FIG. 7 , and then the semi-finished insoles  30  are baked in a baking oven for several minutes to soften the material structure.  
      After step (f) cutting and baking, it proceeds to the last step (g) stamping where the softened semi-finished insoles  30  are put in a cold stamper and stamped into the desired finished products as shown in  FIG. 8 . Because the semi-finished insoles  30  are still soft when taken out of the baking oven, the semi-finished insoles  30  can be stamped into the desired three-dimensional configuration to fit the structure of the shoe. When each semi-finished insole  30  is stamped in the cold stamper, the base sheet material  10  is compacted. After stamping, the base sheet material  10  is maintained in the compacted status, however, due to the material property of latex, the filling material  14  immediately returns to the former shape to protrude over the top and bottom surfaces of the base sheet material  10  and to push a part of the fabric layer  24  outwards, thereby fonning a plurality of raised portions  28 .  
      Referring to  FIGS. 8 and 9 , an insole  30  in accordance with the present invention comprises a base sheet material  10 , a filling material  14 , and a fabric layer  24 . The base sheet material  10  is a sheet member having a plurality of circular through holes  12  through the top and bottom surfaces thereof. The base sheet material  10  is molded from EVA (Ethylene Vinyl Acetate). The filling material  14  is obtained from latex and fixedly secured to the circular through holes  12  and protruded over the top and bottom surfaces of the base sheet material  10 . The fabric layer  24  is covered on the top surface of the base sheet material  10  over the protruded part of the filling material  14 , thereby forming a plurality of raised portions  28 .  
      As indicated above, the invention provides numerous advantages as follows:  
      1. Because the filling material  14  fills up the circular through holes  12  of the base sheet material  10  and protrudes over the top and bottom surfaces of the base sheet material  10 , it is directly supported on the outsole of the shoe and maintained in contact with the user&#39;s sole to receive pressure from the user directly. Therefore, the filling material  14  is constantly maintained protruded over the top and bottom surfaces of the base sheet material  10  even after a long time of use of the insole  30 , giving an elastic support to the user&#39;s sole and good ventilation to the shoe.  
      2. The base sheet material  10  and the filling material  14  can be made of different materials having different hardness to fit different types of shoes.  
      3. The raised portions  28  of the insole  30  can be arranged to provide a massaging effect to massage the user&#39;s sole.