Patent Publication Number: US-9901476-B2

Title: Expansion band with unilateral strain and manufacturing method thereof

Description:
CROSS REFERENCE OF RELATED APPLICATION 
     This is a Divisional application that claims the benefit of priority under 35 U.S.C. § 119 to a non-provisional application, application Ser. No. 13/065,622, filed Mar. 24, 2011. 
    
    
     BACKGROUND OF THE PRESENT INVENTION 
     1. Field of Invention 
     The present invention relates to an expansion band, and more particularly to an expansion band with unilateral resistance and a manufacturing method thereof. 
     2. Description of Related Arts 
     Generally, an expansion band always has an inner cavity capable of being filled with air or liquid to increase its volume, which causes the expansion of the band. However, this kind of expansion is nondirectional so that this expansion band could not provide a directional expansive force, such as a longitudinal expansive force, which is widely used to force vertebras to stretch to eliminate additional pressure between vertebras. 
     In U.S. Pat. No. 7,618,509, Ickchun Chang disclosed a wrinkled band as illustrated in  FIG. 1A  and  FIG. 1B . The wrinkled band comprises a first adhesion sheet  01  and a second adhesion sheet  01  overlapped with each other by an outer peripheral rim  01   a  and an adhesion line  012   a , and an elastic band  06  disposed in the inner space  04  of the overlapped adhesion sheets and connected to the above end and the below end of the adhesion sheets  01  by a connection adhesion band  05 . 
     Referring to  FIG. 2 , the elastic band  06  is stretched by the connection adhesion band  05  and the connection adhesion band  05  is further fixed onto the above below ends of a mounting die  09  to keep the elastic band  06  stretched. The adhesion sheets  01  respectively cover the top bottom surfaces of the mounting die  09  and then are pressed by a high-frequency operating die  08  to form the outer peripheral rim  01   a  and the adhesion line  012   a , thereby the adhesion sheets  01  are overlapped with the elastic band  05  and the connection adhesion band  06  enclosed therein. The outer peripheral rim  01   a  forms the inner space  04  and the adhesion line  012   a  further divides the inner space  04  with certain regularity to form an air passage  02 . As the elastic band  05  is enclosed in the overlapped adhesion sheets  01 , referring to  FIG. 1B , the elastic band  05  is enclosed within the air passage formed by the adhesion line  012   a.    
     The high-frequency operating die  08  further comprises a pressurizing means  07  to press the adhesion sheets  01  with the connection adhesion band  06  together. Hence, referring to  FIG. 1B , the connection adhesion band  06  is adhered to the adhesion sheets  01  on the outer peripheral rim  01  a to fix the elastic band  05  in the air passage  02 , i.e., one end of the elastic band  05  is fixed to an above end of the air passage  02  by a connection adhesion band  06  and another end the elastic band  05  is fixed to an below end the air passage  02  by a connection adhesion band  06 . 
     As mentioned above, the elastic band  05  is disposed within the air passage  02  and is adhered to the overlapped adhesion sheets  01 , when the wrinkled band relaxes, the elastic band  05  contracts to a relaxation situation to wrinkle the adhesion sheets  01  together with a smaller longitudinal length, then when air passage  02  is filled with air, the wrinkled band expands with a bigger longitudinal length and stretches the adhered elastic band  05 , which further strains the adhesion sheets  01  back. That means the elastic band  05  resists the expansion of the expansion band, and the resistance of the elastic band  05  affects the expansive force on all the laterals of the wrinkled band. 
     As the elastic band  05  and the adhesion sheets  01  are fixed together only by the outer peripheral rim  01   a , when the wrinkled band expands, the outer peripheral rim  01   a  not only bears the expansive force provided by the air inside, but also bears the strain force provided by the elastic band  05 . Then as the outer peripheral rim  01   a  is formed only by heated and pressed by the high-frequency operating die  08 , the outer peripheral rim  01   a  cannot bear these forces much, persistently and frequently. That means the outer peripheral rim  01   a  is very easily to be torn up by these forces, resulting that the air will leak out. Finally, the wrinkled band can not be used anymore. 
     Referring to  FIG. 3 , a body is surrounded by the wrinkled band, which is subsequently filled with air to expand, the expansive force on the surface touching the body forces the vertebras to stretch, thereby the additional pressure between the vertebras will be eliminated. However, as the elastic band  05  disposed within the air passage  02  strains all the adhesion sheets  01  back in the opposite direction, the strain force will balance a part of the expansive force. Hence, the expansive force of the wrinkled band is decreased by the resistance of the elastic band  5  and cannot be used effectively to obtain a satisfied treatment effect. 
     Furthermore, considering that the adhesion sheets  01  and the stretched elastic band  05  are pressed together by the high-frequency operating die  08  at the same time, it is very hard to control the pressure. If the pressure is a little smaller, the outer peripheral rim  01   a  will not be strong enough to bear the strain force of the elastic band  05 , then the adhesion sheets  01  will be torn up to cause a waste product. Besides, the high-frequency operating die  08  is always heated to weld the adhesion sheets  01  together, and then the adhesion sheets  01  are cooled to form the outer peripheral rim  01   a . However, if the heating time or the cooling time is not controlled well, a waste product will be obtained. 
     SUMMARY OF THE PRESENT INVENTION 
     It will be appreciated that the present invention provides an expansion band capable of expanding when filled with air. 
     It will be appreciated that the present invention provides an expansion band with an inner space and a plurality of air passages formed by bonding a first layer and a second layer in accordance with a pre-determined pattern. 
     It will be appreciated that the present invention provides an expansion band with an inner space and a plurality of air passages formed by bonding a first layer and a second layer along a bond line. 
     It will also be appreciated that the present invention provides an expansion band with a shrinking layer for shrinking the expansion band. 
     It will also be appreciated that the present invention provides an expansion band with enhanced expansive force. 
     Accordingly, the present invention is directed to an expansion band, which comprises a first layer, a second layer, a shrinking layer for shrinking the first layer and the second layer, a bond line for sealing the first layer and the second layer to form an inner space therein and dividing the inner space into a plurality of air passages communicated with each other, a plurality of air passages formed between the first layer and the second layer, and an air nozzle for communicating with the air passage. 
     In a preferred embodiment of the present invention, the shrinking layer is bonded to the outline of the second layer. 
     In a preferred embodiment of the present invention, the shrinking layer comprises a third layer and a plurality of elastic bands attached thereon. 
     In a preferred embodiment of the present invention, the expansion band comprises a bond line for forming an inner space between the first layer and the second layer, dividing the inner space into a plurality of air passages communicated with each other, and forming a plurality of passages between the second layer and the third layer, a plurality of air passages formed between the first layer and the second layer. 
     In a preferred embodiment of the present invention, the expansion band comprises a plurality of passages for guiding the elastic band to pass through, wherein the elastic band is disposed between the second layer and the third layer. 
     In a preferred embodiment of the present invention, the bond line bonds the first layer, the second layer and the third layer together. 
     In a preferred embodiment of the present invention, the bond line bonds outline and pre-determined regions of the first layer and the second layer together, and the shrinking layer attaches to the second layer to shrink the first layer and the second layer, the plurality of air passages disposed between the first layer and the second layer. 
     The present invention further provide a method of manufacturing an expansion band, which comprises the steps: 
     (a) bonding a first layer, a second layer and a third layer of a shrinking layer together to form a bond line, wherein the first layer and the second layer are sealed by the bond line on outline to form an inner space between the first layer and the second layer, the inner space is divided by the bond line into a plurality of air passages; 
     (b) providing a plurality of elastic bands to extend between the second layer and the third layer, and fixing the elastic bands onto outline of the first layer, the second layer and the third layer. 
     In a preferred embodiment of the present invention, step (a) further comprises: 
     pressing the first layer, the second layer and the third layer to a die with pre-determined pattern; 
     forming the bond line in accordance to the pre-determined pattern of the die to bond the first layer, the second layer, and the third layer together; 
     wherein the bond line seals outline of the first layer and second layer to form the inner space and bonds regions of the first layer and second layer to divide the inner space into the plurality of air passages capable of communicating with each other. 
     In a preferred embodiment of the present invention, step (b) further comprises: 
     guiding the elastic bands to enter the passages; 
     stretching the elastic bands to pass through the passages; 
     fixing the elastic bands in stretching state onto the first layer, the second layer and the third layer. 
     In a preferred embodiment of the present invention, the method further comprises a step (c) of connecting an air nozzle to the air passage. 
     These and other objectives, features, and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a perspective view of a wrinkled band according to the prior art. 
         FIG. 1B  is an enlarged partial view of the connection adhesion band and the elastic band of  FIG. 1A . 
         FIG. 2  is a cross-section view showing the procedure of pressing the adhesion sheets, the connection adhesion band and the elastic band by the high-frequency operating die. 
         FIG. 3  illustrates the force distribution of the expanded wrinkled band of  FIG. 1 . 
         FIG. 4  is an exploded view of an expansion band according to a first preferred embodiment of the present invention. 
         FIG. 5A  is a perspective view of the unexpanded expansion band according to the above preferred embodiment of the present invention. 
         FIG. 5B  is a perspective view of the expanded expansion band according to the above preferred embodiment of the present invention. 
         FIG. 6A  is a perspective view illustrating the pressing procedure according to the above preferred embodiment of the present invention. 
         FIG. 6B  is a perspective view of the product manufactured by the pressing procedure of  FIG. 6A . 
         FIG. 7A  is an A-A section view of the product of  FIG. 6B . 
         FIG. 7B  is a B-B section view of the product of  FIG. 6B . 
         FIG. 7C  is a C-C section view of the product of  FIG. 6B . 
         FIG. 7D  is a D-D section view of the product of  FIG. 6B . 
         FIG. 8A  is a perspective view illustrating the procedure of providing the elastic means to the product in  FIG. 6B . 
         FIG. 8B  is a perspective view illustrating the product manufactured by the procedure of  FIG. 8A . 
         FIG. 9A  is an A-A section view of the product of  FIG. 8B . 
         FIG. 9B  is a B-B section view of the product of  FIG. 8B . 
         FIG. 9C  is a C-C section view of the product of  FIG. 8B . 
         FIG. 9D  is a D-D section view of the product of  FIG. 8B . 
         FIG. 10A  is a perspective view illustrating the pressing procedure according to another preferred embodiment of the present invention. 
         FIG. 10B  is a perspective view of the product manufactured by the pressing procedure of  FIG. 10A . 
         FIG. 11A  is an A-A section view of the product of  FIG. 10B . 
         FIG. 11B  is a B-B section view of the product of  FIG. 10B . 
         FIG. 11C  is a C-C section view of the product of  FIG. 10B . 
         FIG. 11D  is a D-D section view of the product of  FIG. 10B . 
         FIG. 12A  is a perspective view illustrating the procedure of providing the elastic means to the product in  FIG. 10B . 
         FIG. 12B  is a perspective view illustrating the product manufactured by the procedure of  FIG. 12A . 
         FIG. 13A  is an A-A section view of the product of  FIG. 12B . 
         FIG. 13B  is a B-B section view of the product of  FIG. 12B . 
         FIG. 13C  is a C-C section view of the product of  FIG. 12B . 
         FIG. 13D  is a D-D section view of the product of  FIG. 12B . 
         FIG. 14A  is a perspective view illustrating the pressing procedure with a protection layer according to another preferred embodiment of the present invention. 
         FIG. 14B  is a perspective view of the product manufactured by the pressing procedure of  FIG. 10A . 
         FIG. 15A  is an A-A section view of the product of  FIG. 14B . 
         FIG. 15B  is a B-B section view of the product of  FIG. 14B . 
         FIG. 15C  is a C-C section view of the product of  FIG. 14B . 
         FIG. 15D  is a D-D section view of the product of  FIG. 14B . 
         FIG. 15E  is an E-E section view of the product of  FIG. 14B . 
         FIG. 16A  is a perspective view illustrating the procedure of providing the elastic means to the product in  FIG. 14B . 
         FIG. 16B  is a perspective view illustrating the product manufactured by the procedure of  FIG. 16A . 
         FIG. 17A  is an A-A section view of the product of  FIG. 16B . 
         FIG. 17B  is a B-B section view of the product of  FIG. 16B . 
         FIG. 17C  is a C-C section view of the product of  FIG. 16B . 
         FIG. 17D  is a D-D section view of the product of  FIG. 16B . 
         FIG. 17E  is an E-E section view of the product of  FIG. 16B . 
         FIG. 18A  is an enlarged partial view of the product manufactured by the pressing procedure illustrating the cut thereon. 
         FIG. 18B  is a perspective view illustrating the sewing procedure of the expansion band according to the above preferred embodiment. 
         FIG. 19  illustrates the force distribution of the expansion band of  FIG. 4 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIG. 4 ,  FIG. 5A  and  FIG. 5B , an expansion band according to a preferred embodiment of the present invention is illustrated. The expansion band comprises a first layer  1   a , a second layer  1   b , a bond line  3  for sealing the first layer  1   a  and the second layer  1   b  to form an inner space  10  therein and dividing the inner space  10  into a plurality of air passages  4 , as shown in  FIGS. 7A-7D , communicated with each other, a shrinking layer  2  for shrinking the first layer  1   a  and the second layer  1   b , and an air nozzle  40  capable of communicating with the air passage  4 . 
     The first layer  1   a  and the second layer  1   b  are pressed to a die  9  having pre-determined pattern, thereby the outlines  11  of the first layer  1   a  and the second layer  1   b  are bonded together to form the inner space  10  therein, which is sealed. Furthermore, in accordance to the pre-determined pattern of the die  9 , a plurality of regions  12  in the central areas of the first layer  1   a  and the second layer  1   b  are bonded together to divide the inner space  10  into the plurality of air passages  4 , which are communicated with each other. So not only are the outlines  11  of the first layer  1   a  and the second layer  1   b  are adhered, but also some regions  12  are adhered in accordance to the pre-determined pattern; hence the inner space  10  formed between the first layer  1   a  and the second layer  1   b  is actually composed of a plurality of line-shape inner spaces, which let the air pass through to form a plurality of air passages  4 . The bonded outlines  11  and the bonded regions  12  form the bond line  3 , which means the bond line  3  seals the first layer  1   a  and the second layer  1   b  to form the inner space  10  and further divide the inner space  10  into the plurality of air passages  4 . 
     The shrinking layer  2  is bonded to the outline  11  of the second layer  1   b  and is capable of shrinking. Hence, when the expansion band is unexpanded as illustrated in  FIG. 5A , the shrinking layer  2  shrinks and further strains the first layer  1   a  and the second layer  1   b  to the centre, so that the first layer  1   a  and the second layer  1   b  are shrunk and have wrinkles thereon. 
     Then when the expansion band is filled with air through the air nozzle  40  to expand, the first layer  1   a  and the second layer  1   b  are unfolded as illustrated in  FIG. 5B . Along the expansion of the expansion band, the unfolded first layer  1   a  and the second layer  1   b  are stretching the shrinking layer  2  to extend, and then the shrinking layer  2  will generate a strain force to resist the extension. The strain force of the shrinking layer  2  is increased along the extension and further strains the first layer  1   a  and the second layer  1   b  back against the expansion. However, along the expansion of the expansion band, the expansive force is also being increased to gradually balance the strain force. Finally, the expansion band is expanded as illustrated in  FIG. 5B , with the shrinking layer  2  stretched. 
     Then when the air in the expansion band is discharged through the air nozzle  40 , the expansive force is decreased along the discharging and cannot balance the strain force of the shrinking layer  2  anymore. As a result, the shrinking layer shrinks and strains the first layer  1   a  and the second layer  1   b  to the centre, and finally the expansion band is shrunk as illustrated in  FIG. 5A . 
     In a preferred embodiment of the present invention, the shrinking layer  2  comprises a third layer  21  and a plurality of elastic bands  22  attached thereon, wherein the elastic bands  22  parallel extends on the outer surface of the second layer  1   b  in the width direction thereof. 
     In order to shrink the first layer  1   a  and the second layer  1   b , the elastic band  22  is fixed to the outline  11  on two sides of the second layer  1   b  in a stretching state. That means after the air passages  4  are formed, the elastic bands  22  are respectively stretched to extend on the outer surfaces of the second layer  1   b  and then two ends of each elastic band  22  are fixed onto the outline  11  on two sides of the second layer  1   b.    
     Hence, when there is no expansive force, the stretched elastic bands  22  will strain the sealed first layer  1   a  and second layer  1   b  along the width direction, so that the sealed first layer  1   a  and second layer  1   b  are shrunk by the elastic bands  22  and have the width decreased. 
     In a preferred embodiment of the present invention, the elastic band  22  extends along the outer surface of the air passage  4 . And at least one elastic band  22  extends along the bond line  3 . 
     In a preferred embodiment of the present invention, the first layer  1   a , the second layer  1   b  and the shrinking layer  2  are bonded together as illustrated in  FIG. 6A . 
     The third layer  21  of the shrinking layer  2 , the second layer  1   b  and the first layer  1   a  are provided onto the die  9  in turn, wherein the die  9  has pre-determined pattern disposed thereon. Then the first layer  1   a , the second layer  1   b  and the third layer  21  are pressed down to the die  9  with a pre-determined pressure. It is preferred that the die  9  has already been heated to a pre-determined temperature to heat the third layer  21 , the second layer  1   b  and the first layer  1   a  provided thereon. Due to the press and/or the heat, the bond line  3  is formed in accordance to the pre-determined pattern of the die  9  to bond the first layer  1   a , the second layer  1   b  and the third layer  21  together. 
     As mentioned above, the bond line  3  bonds the outline  11  of the first layer  1   a  and second layer  1   b  to seal them and to form the inner space  10  therein, and bonds some regions  12  of the first layer  1   a  and second layer  1   b  to divide the inner space  10  into the plurality of air passages  4  communicated with each other. It is preferred that the third layer  21  is also bonded to the second layer  1   b  by the bond line  3 . 
     Referring to  FIG. 6B , the first layer  1   a , the second layer  1   b  and the third layer  21  are bonded together on the positions of the bonded regions  12 , so that the air passages  4  are generated in the inner space  11  between the first layer  1   a  and the second layer  1   b  while a plurality of passages  23  are also generated between the second layer  1   b  and the third layer  21  for guiding the elastic bands  22  to drill through. 
     Referring to  FIG. 7A , the first layer  1   a  and the second layer  1   b  are bonded together on the outline  11  to form the inner space  10 . An air passage  4  is generated in the inner space  10 , while a passage  23  is generated between the second layer  1   b  and the third layer  21  to let the elastic band  22  pass through. 
     Referring to  FIG. 7B , the first layer  1   a , the second layer  1   b  and the third layer are bonded together not only on the outline  11 , but also on the regions  12 . The air passages  4  are generated in the inner space  10  formed between the first layer  1   a  and the second layer  1   b.    
     Referring to  FIG. 7C , the first layer  1   a , the second layer  1   b  and the third layer  21  are bonded together on the regions  12  to form the air passages  4  in the inner space  10  between the first layer  1   a  and the second layer  1   b  and to form the passages  23  between the second layer  1   b  and the third layer  21  to let the elastic bands  22  pass through. 
     Referring to  FIG. 7D , some portions of the first layer  1   a , the second layer  1   b  and the third layer  21  are not bonded together. Hence, the inner space  10  between the first layer  1   a  and the second layer  1   b  forms an air passage  4  here, which is communicates with the air passages  4  shown in  FIGS. 7A and 7B . 
     The elastic band  22  is guided to pass through the passage  23  formed between the second layer  1   b  and the third layer  2  as illustrated in  FIG. 8A . As mentioned above, the elastic band  22  is in a stretching state in the passage  23 . That means, the elastic band  22  is guided to enter the passage  23  and stretched to pass through the passage  23 . 
     It is preferred that one end of the elastic band  22  is fixed onto an external frame  91 , then another end of the elastic band  22  is guided to enter the passage  23  and is stretched to pass through the passage  23  and is fixed onto another external frame  92 . 
     Hence, the elastic band  22  keeps the stretching state in the passage  12  when and after being guided to pass through the passage  23 . 
     Referring to  FIG. 18B , when the required elastic bands  22  are all passed through the passages  23 , stretched elastic bands  22  are fixed with the first layer  1   a , the second to layer  1   b  and the third layer  21  on the outline  11 . Better still, the first layer  1   a , the second layer  1   b  and the third layer  21  are sewn together alone the outline  11 , thereby the elastic bands  22  are also sewn with the first layer  1   a , the second layer  1   b  and the third layer  21 . That causes the elastic bands  22  are in stretching state when being fixed or sewed to the first layer  1   a , the second layer  1   b  and the third layer  21 . Hence, the elastic bands  22  will shrink to strain the first layer  1   a , the second layer  1   b  and the third layer  21  back as illustrated in  FIG. 5A . 
     Referring to  FIG. 8B , the elastic band  22  is stretched and guided to extend on the outer surface of the second layer  1   b  and to pass through the passage  23  formed between the second layer  1   b  and the third layer  21 . 
     Referring to  FIG. 9A , an elastic band  22  has been guided to pass through the passage  23  formed between the second layer  1   b  and the third layer  21 . The elastic band  22  is disposed on the outer surface of the second layer  1   b  and on the air passage  4  formed between the first layer  1   a  and the second layer  1   b.    
     Referring to  FIG. 9B , as the first layer  1   a , the second layer  1   b  and the third layer are bonded together not only on the outline  11 , but also on the regions  12 , only the air passages  4  are formed, while no passage  23  is formed between the second layer  1   b  and the third layer  21 . Hence, no elastic band  22  is disposed here. 
     Referring to  FIG. 9C  and  FIG. 9D , as the first layer  1   a , the second layer  1   b  and the third layer  21  are bonded together on the regions  12 , not only air passages  4  are formed in the inner space  10  between the first layer  1   a  and the second layer  1   b , but also the passages  23  are formed between the second layer  1   b  and the third layer  21 . Hence, the elastic bands  22  can be guided to pass through these passages  23  in the stretching state. These elastic bands  22  are disposed on the outer surface of the second layer  1   b  and on the air passages  4 . 
     In another preferred embodiment of the present invention, a first plurality of elastic bands  21  are pre-provided on the third layer  21  of the shrinking layer  2 , which is bonded together with the first layer  1   a  and the second layer  1   b  as illustrated in  FIG. 10A . 
     The first plurality of elastic bands  22  could be adhered to the third layer  21  before the pressing procedure, or could be bonded to, be sewn to or be fixed to the third layer  21  by any other suitable method before the pressing procedure. Furthermore, these elastic bands  22  are fixed to the third layer  21  in stretching state, which means these elastic bands  22  are stretched to extend along the wide direction of the third layer  21  and then are fixed onto the corresponding positions of the outline of the third layer  21 . 
     As illustrated in  FIG. 10A  and  FIG. 10B , the third layer  21  of the shrinking layer  2 , the second layer  1   b  and the first layer  1   a  are provided onto the die  9  in turn, wherein the die  9  has pre-determined pattern disposed thereon, and wherein the first plurality of elastic bands  22  pre-provided on the third layer  21  are disposed between the second layer  1   b  and the third layer  21 . 
     Then the first layer  1   a , the second layer  1   b  and the third layer  21  are pressed down to die  9  with a pre-determined pressure. As mentioned above, it is preferred that the die  9  has been pre-heated to a pre-determined temperature to heat the third layer  21 , the second layer  1   b  and the first layer  1   a  provided thereon. Due to the press and/or the heat, the bond line  3  is formed in accordance to the pre-determined pattern of the die  9  to bond the first layer  1   a , the second layer  1   b  and the third layer  21  together. 
     Better still, the first plurality of elastic bands  22  are arranged in such a manner that the elastic bands  22  are bonded to the second layer  1   b  by the bond line  3  on parts of the regions  12  in the pressing procedure. As illustrated in  FIG. 10B , two air passages  4  are separated by the bond line  3  on the nearby regions  12 , which has no elastic band  22  disposed thereon in the pressing procedure as illustrated in  FIGS. 6A and 6B , but has an elastic band  22  crossing the third layer  21  fixed or bonded thereon in the pressing procedure as illustrated in  FIGS. 10A and 10B . 
     Therefore, before the pressing procedure, the first plurality of elastic bands  22  are provided in stretching state onto the third layer  21  on the pre-determined positions as mentioned above, and then are bonded together with the first layer  1   a , the second layer  1   b  and the third layer  21  by the bond line  3 . Hence, the first plurality of elastic bands  22  extend on the outer surface of the air passages  4  and part of the bond line  3  to cross the width of the third layer  21 . 
     Referring to  FIG. 11A , the first layer  1   a  and the second layer  1   b  are bonded together on the outline  11  to form the inner space  10 . An air passage  4  is generated in the inner space  10 , while a passage  23  is generated between the second layer  1   b  and the third layer  21  to let the elastic band  22  pass through. 
     Referring to  FIG. 11B , the first layer  1   a , the second layer  1   b  and the third layer  21  are bonded together not only on the outline  11 , but also on the regions  12 , wherein an elastic band  22  of the first plurality of elastic bands  22  are disposed between the second layer  1   b  and the third layer  21  and are bonded with the first layer  1   a , the second layer  1   b  and the third layer  21  on the regions  12 . The air passages  4  are generated in the inner space  10  formed between the first layer  1   a  and the second layer  1   b.    
     Referring to  FIG. 11C , the first layer  1   a , the second layer  1   b , the third layer  21  and the first plurality of elastic bands  22  are bonded together on the regions  12 , resulting that the air passages  4  in the inner space  10  are formed between the first layer  1   a  and the second layer  1   b , and the passages  23  are formed between the second layer  1   b  and the third layer  21  to let the second plurality of elastic bands  22  pass through. 
     Referring to  FIG. 11D , some portions of the first layer  1   a , the second layer  1   b  and the third layer  21  are not bonded together. Hence, the inner space  10  between the first layer  1   a  and the second layer  1   b  forms an air passage  4  here, which is communicated with the air passages  4  shown in  FIGS. 11A and 11B . And the first plurality of elastic bands  22  are disposed on the outer surface of this air passage  4  without being bonded to the second layer  1   b  and the third layer  21 . Hence, these no-bonded portions of the first plurality of elastic bands  22  will strain to provide the strain force and further shrink the first layer  1   a  and the second layer  1   b  nearby. 
     The elastic bands  22  pre-provided on the third layer  21  are better coupled with the first layer  1   a  and the second layer  1   b  than those in  FIGS. 6A and 6B , hence, the elastic bands  22  pre-provided on the third layer  21  will better shrink the first layer  1   a  and the second layer  1   b  and more easily form the wrinkles thereon. However, as the elastic bands  22  pre-provided on the third layer  21  are partly fixed to the second layer  1   b  on the regions  12 , they cannot provide strain forces as large as those in  FIGS. 6A and 6B . 
     In order to provide enough strain forces to expansion band by the shrinking layer  2 , it is preferred that a second plurality of elastic bands  22  are guided to drill through the passages  23  formed between the second layer  1   b  and the third layer  21  by the bond line  3 . 
     The elastic band  22  of the second plurality of elastic band  22  is guided to pass through the passage  23  formed between the second layer  1   b  and the third layer  2  as illustrated in  FIG. 12A . As mentioned above, the elastic band  22  is in a stretching state in the passage  23 . That means, the elastic band  22  is guided to enter the passage  23  and is stretched to pass through the passage  23 . As mentioned above, one end of the elastic band  22  is fixed onto an external frame  91 , and then another end of the elastic band  22  is guided to enter the passage  23  and is stretched to pass through the passage  23  and is fixed onto another external frame  92 . Theses stretched elastic bands  22  are fixed with the first layer  1   a , the second layer  1   b  and the third layer  21  on the outline  11  as mentioned above. 
     Referring to  FIG. 12B , while the first plurality of elastic bands  22  have already been disposed between the second layer  1   b  and the third layer  21 , each elastic band  22  of the second plurality of elastic bands  22  is stretched and guided to extend on the outer surface of the second layer  1   b  and to pass through the passage  23  formed between the second layer  1   b  and the third layer  21 . 
     Referring to  FIG. 13A , an elastic band  22  has been guided to pass through the passage  23  formed between the second layer  1   b  and the third layer  21 . The elastic band  22  is disposed on the outer surface of the second layer  1   b  and on the air passage  4  formed between the first layer  1   a  and the second layer  1   b.    
     Referring to  FIG. 13B , as the first layer  1   a , the second layer  1   b  and the third layer are bonded together not only on the outline  11 , but also on the regions  12 , 
     Referring to  FIG. 13B , an elastic band  22  of the first plurality of elastic bands  22  are disposed between the second layer  1   b  and the third layer  21  and are bonded with the first layer  1   a , the second layer  1   b  and the third layer  21  on the regions  12 . Hence, only the air passages  4  are formed, while no passage  23  is framed between the second layer  1   b  and the third layer  21 , so that, no elastic band  22  of the second plurality of elastic bands  22  is disposed here. 
     Referring to  FIG. 13C  and  FIG. 13D , as the first layer  1   a , the second layer  1   b  and the third layer  21  are bonded together on the regions  12 , not only air passages  4  are formed in the inner space  10  between the first layer  1   a  and the second layer  1   b , but also the passages  23  are formed between the second layer  1   b  and the third layer  21 . Hence, the second plurality of elastic bands  22  can be guided to pass through these passages  23  in the stretching state and disposed on the outer surface of the second layer  1   b  and on the air passages  4 . As the first plurality of elastic bands  21  have already been disposed between the second layer  1   b  and the third layer  21 , hence the first plurality and the second plurality of elastic bands  22  both exist in the expansion band. 
     In this embodiment, with the effect of the first and the second plurality of elastic bands  22 , the shrinking layer  2  could provide various strain forces to better shrink the expansion band. With various arrangements of the first and the second pluralities of elastic bands  22 , the expansion band could be manufactured with different strain force according to the requirement. 
     In another preferred embodiment of the present invention, the first layer  1   a , the second layer  1   b  and the shrinking layer  2  are bonded together as illustrated in  FIG. 14A  with a protection layer  5  for protecting the third layer  21  of the shrinking layer  2  from being bonded to the second layer  1   b  and the first layer  1   a . The protection layer  5  is disposed between the shrinking layer  2  and the second layer  1   b  and has a pre-determined pattern to cover corresponding portions of the third layer  21 . 
     The third layer  21  of the shrinking layer  2 , the protection layer  5 , the second layer  1   b  and the first layer  1   a  are provided onto the die  9  in turn, wherein the die  9  has pre-determined pattern disposed thereon. Then the first layer  1   a , the second layer  1   b , the protection layer  5  and the third layer  21  are pressed down to the die  9  with a pre-determined pressure. The pattern of the protection layer  5  is designed to cover part of the third layer  21  to resist the bonding to this part, and thereby a passage  23  for guiding an elastic band  22  to pass through is formed between the third layer  21  and the second layer  1   b.    
     Referring to  FIG. 14B , the first layer  1   a , the second layer  1   b  and the third layer  21  are bonded together on the positions of the bonded regions  12 , so that the air passages  4  are generated in the inner space  11  formed between the first layer  1   a  and the second layer  1   b  while a plurality of passages  23  are also generated between the second layer  1   b  and the third layer  21  for guiding the elastic bands  22  to drill through. 
     If not protected by the protection layer  5 , the regions  12  on the third layer  21  will be bonded to the second layer  1   b  by being pressed to the die  9 , but if protected by the protection layer  5 , the regions  12  will separate from the second layer  1   b  to form inner space therein. Hence, due to the protection layer  5  and its pre-determined pattern, part of the regions  12  of the third layer  21  are not bonded to the second layer  1   b  to form additional passages  23  as illustrated in  FIG. 14B . 
     As mentioned above, the bond line  3  is formed in accordance to the pre-determined pattern of the die  9  to bond the first layer  1   a , the second layer  1   b  and the third layer  21  together under the press and/or the heat of the die  9 . That means the material of the second layer  1   b  and the material of the third layer  21  could be heat-sealed, heat-welded, and adhered and so on to be bonded together, and even to be integrated together. Hence, the protection layer  5  should be made of the material which could stop these kinds of heat-sealing, hear-welding, and adhering and so on. 
     Referring to  FIG. 15A , the first layer  1   a  and the second layer  1   b  are bonded together on the outline  11  to form the inner space  10 . An air passage  4  is generated in the inner space  10 , while a passage  23  is generated between the second layer  1   b  and the third layer  21  to let the elastic band  22  pass through. 
     Referring to  FIG. 15B , the first layer  1   a , the second layer  1   b  and the third layer are bonded together not only on the outline  11 , but also on the regions  12 . The air passages  4  are generated in the inner space  10  formed between the first layer  1   a  and the second layer  1   b.    
     Referring to  FIG. 15E , the first layer  1   a  and the second layer  1   b  are bonded together not only on the outline  11 , but also on the regions  12 . However, these regions  12  of the third layer  21  are protected by the protection layer  5  from being bonded to the second layer  1   b , thereby that an additional passage  23  is formed on these regions  12 , which would be boned together if there is no protection layer  5 . 
     Referring to  FIG. 15C , the first layer  1   a , the second layer  1   b  and the third layer  21  are bonded together on the regions  12  to form the air passages  4  in the inner space  10  between the first layer  1   a  and the second layer  1   b  and to form the passages  23  between the second layer  1   b  and the third layer  21  to let the elastic bands  22  pass through. As the additional passage  23  is formed by non-bonding of the regions  12 , which actually separate the nearby passages  23 , the additional passage  23  actually integrates with two nearby passages  23  to form a wide passage  230 , which could permit at least two elastic bands  22  or a wide elastic band  220  to pass through. 
     Referring to  FIG. 15D , some portions of the first layer  1   a , the second layer  1   b  and the third layer  21  are not bonded together. Hence, the inner space  10  between the first layer  1   a  and the second layer  1   b  forms an air passage  4  here, which communicates with the air passages  4  shown in  FIGS. 15A and 15B . 
     The elastic band  22  is guided to pass through the passage  23  and/or the additional passage  23  formed between the second layer  1   b  and the third layer  2  in the stretching state as illustrated in  FIG. 16A . As mentioned above, the additional passage  23  actually integrates with two nearby passages  23  to form a wide passage  230 , a wide elastic band  220  could be guided to pass through, as illustrated in  FIGS. 16A and 16B . 
     Referring to  FIG. 16B , the elastic band  22  is stretched and guided to extend on the outer surface of the second layer  1   b  and to pass through the passage  23  formed between the second layer  1   b  and the third layer  21 . 
     Referring to  FIG. 17A , an elastic band  22  has been guided to pass through the passage  23  formed between the second layer  1   b  and the third layer  21 . The elastic band  22  is disposed on the outer surface of the second layer  1   b  and on the air passage  4  formed between the first layer  1   a  and the second layer  1   b.    
     Referring to  FIG. 17B , as the first layer  1   a , the second layer  1   b  and the third layer are bonded together not only on the outline  11 , but also on the regions  12 , only the air passages  4  are formed, while no passage  23  is formed between the second layer  1   b  and the third layer  21 . Hence, no elastic band  22  is disposed here. 
     Referring to  FIG. 17E , which is different from  FIG. 17B , the regions  12  of the third layer  21  are protected by the protection layer  5  from being bonded to the second layer  1   b , thereby that an additional passage  23  is formed here and has an elastic band drilled through. 
     Referring to  FIG. 17C  and  FIG. 17D , as the first layer  1   a , the second layer  1   b  and the third layer  21  are bonded together on the regions  12 , not only air passages  4  are formed in the inner space  10  between the first layer  1   a  and the second layer  1   b , but also the passages  23  are formed between the second layer  1   b  and the third layer  21 . Hence, the elastic bands  22  can be guided to pass through these passages  23  in the stretching state. Furthermore, as mentioned above, the additional passage  23  and two nearby passages  23  could compose a wide passage  230 , which could permit a wide elastic band  20  pass through. Hence, the expansion band illustrated in  FIGS. 17C and 17D  has a plurality of passages  23  with elastic bands  22  disposed therein and at least one wide passage  230  with wide elastic band  220  disposed therein. 
     In this embodiment, as the wide elastic band  220  has big strain force than the elastic band  22 , the wide passage  230  and the wide elastic band  220  could be used to partially enhance the shrinking of the shrinking layer  2 . If a portion of the expansion band is shrunk more, when expansion band is filled with air, this portion will expand more than the other portion, which means this portion will provide more expansive force. Hence, expansion band has partially enhanced expansive force. Hence, the protection layer  5  could be designed with a pattern to form the wide passage  230  on special position of the expansion band. And that will further made the expansion band could provide enhanced expansive force on special position according to the requirement. 
     Referring to  FIGS. 18A and 18B , a plurality of cuts  61  could be disposed on the outlines  11  of the expansion band with a pre-determined certain distance. When sewing along the outline  11  of the expansion band with a sleeve  62 , two edges of each cut  61  will be sewed together to reduce the perimeter of the expansion band. This will balance the elastic deformation of the expanded expansion band to make the expansion band fit the human body better. 
     Referring to  FIG. 19 , as the shrinking layer  2  is disposed on single side of the expansion band, the expansion band will be strained unilaterally by the shrinking layer  2 , which means the expansion band will bear a unilateral strain of the shrinking layer  2 . Hence, the expansive force on the side with shrinking layer  2  will be balanced by the unilateral strain force, resulting that the expansive deformation on the side with shrinking layer  2  is less than that on the other side. This will further make the expansion band fit the human body by surrounding the human body by the expansion band with the shrinking layer  2  attached to the human body. 
     Furthermore, when the side with shrinking layer  2  attaches to a human body, the side will directly provide an expansive force to the human body. As the other side has a bigger expansive deformation, its two ends will provide part of the expansive force on this side to the human body. Hence, the effective expansive force provided to the human body is actually increased and enhanced. 
     As the elastic bands  22  of the shrinking layer  2  are sewed to the first layer  1   a  and the second layer  1   b  instead of being adhered to the first layer  1   a  and the second layer, the strain force of the stretched elastic bands  22  will not directly effect on the bonded outline, the first layer  1   a  and the second layer  1   b  are bonded strong enough to avoid from being broken by the strain force of the elastic bands  22 . 
     One skilled in the art will understand that the embodiment of the present invention as shown in the drawings and described above is exemplary only and not intended to be limiting. 
     It will thus be seen that the objects of the present invention have been fully and effectively accomplished. It embodiments have been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.