Patent Publication Number: US-7584848-B2

Title: Structure of air-packing device

Description:
FIELD OF THE INVENTION 
   This invention relates to a structure of an air-packing device for use as packing material, and more particularly, to a structure of an air-packing device and check valves incorporated therein for achieving an improved shock absorbing capability to protect a product from a shock or impact by packing the product within a space having a shape unique to the product while allowing easy placement and takeout of the package. 
   BACKGROUND OF THE INVENTION 
   In product distribution channels such as product shipping, a Styrofoam packing material has been used for a long time for packing commodity and industrial products. Although the styrofoam package material has a merit such as a good thermal insulation performance and a light weight, it has also various disadvantages: recycling the styrofoam is not possible, soot is produced when it burns, a flake or chip comes off when it is snagged because of it&#39;s brittleness, an expensive mold is needed for its production, and a relatively large warehouse is necessary to store it. 
   Therefore, to solve such problems noted above, other packing materials and methods have been proposed. One method is a fluid container of sealingly containing a liquid or gas such as air (hereafter also referred to as an “air-packing device”). The air-packing device has excellent characteristics to solve the problems involved in the styrofoam. First, because the air-packing device is made of only thin sheets of plastic films, it does not need a large warehouse to store it unless the air-packing device is inflated. Second, a mold is not necessary for its production because of its simple structure. Third, the air-packing device does not produce a chip or dust which may have adverse effects on precision products. Also, recyclable materials can be used for the films forming the air-packing device. Further, the air-packing device can be produced with low cost and transported with low cost. 
     FIG. 1  shows an example of structure of an air-packing device in the conventional technology. The air-packing device  20  includes a plurality of air containers  22  and check valves  24 , a guide passage  21  and an air input  25 . The air from the air input  25  is supplied to the air containers  22  through the air passage  21  and the check valves  24 . Typically, the air-packing device  20  is composed of two thermoplastic films which are bonded together at bonding areas  23   a.    
   Each air container  22  is provided with a check valve  24 . One of the purposes of having multiple air containers with corresponding check valves is to increase the reliability, because each air container is independent from the others. Namely, even if one of the air containers suffers from an air leakage for some reason, the air-packing device can still function as a shock absorber for packing the product because other air containers are still inflated because of the corresponding check valves. 
     FIG. 2  is a plan view of the air-packing device  20  of  FIG. 1  when it is not inflated which shows bonding areas for closing two thermoplastic films. The thermoplastic films of the air-packing device  20  are bonded (heat-sealed) together at bonding areas  23   a  which are rectangular periphery thereof to air tightly close the air-packing device  20 . The thermoplastic films of the air-packing device  20  are also bonded together at bonding areas  23   b  which are boundaries of the air containers  22  to air-tightly separate the air containers  22  from one another. 
   When using the air-packing device, each air container  22  is filled with the air from the air input  25  through the guide passage  21  and the check valve  24 . After filling the air, the expansion of each air container  22  is maintained because each check-valve  24  prevents the reverse flow of the air. The check valve  24  is typically made of two small thermoplastic films which are bonded together to form an air pipe. The air pipe has a tip opening and a valve body to allow the air flowing in the forward direction through the air pipe from the tip opening but the valve body prevents the air flow in the backward direction. 
   Air-packing devices are becoming more and more popular because of the advantages noted above. There is an increasing need to store and carry precision products or articles which are sensitive to shocks and impacts often involved in shipment of the products. There are many other types of product, such as wine bottles, DVD drivers, music instruments, glass or ceramic wares, antiques, etc. that need special attention so as not to receive a shock, vibration or other mechanical impact. Thus, it is desired that the air-packing device protects the product to minimize the shock and impact. An air-packing structure is desired that can securely hold a package to be protected while facilitating easy placement of the package. 
   SUMMARY OF THE INVENTION 
   It is, therefore, an object of the present invention to provide a structure of an air-packing device for packing a product that can minimize a shock or vibration and protect the product. 
   It is another object of the present invention to provide a structure of an air-packing device for packing a product by a packing space created by the air-packing device through a top opening which is designed to easily open and close the air-packing device. 
   In one aspect of the present invention, an air-packing device inflatable by compressed air for protecting a product therein when stored in a container box, comprising: first and second thermoplastic films superposed with each other where predetermined portions of the first and second thermoplastic films are bonded, thereby creating a plurality of air containers; a plurality of heat-seal lands each sealing the first and second thermoplastic films in a small area of the air container in a manner to allow air flow between the air cells, thereby creating a plurality of series connected air cells for each air container; a plurality of check valves for corresponding air containers established between the first and second thermoplastic films for allowing the compressed air to flow in a forward direction; an air input commonly connected to the plurality of check valves to supply the compressed air to all of the air cells through the check valves. A part of a set of the air cells at one end of the air-packing device and a part of a set of the air cells at another end of the air-packing device are not bonded to create a top opening having a pair flap portions symmetrical with one another to open and close the air-packing device. 
   In another aspect, a most part a set of the air cells at one end of the air-packing device is not bonded to create a top opening having a flap portion to open and close the air-packing device, and wherein an end of the flap portion comes under the air cells at another end when the air-packing device is closed. 
   The heat-seal lands at the bottom of the air-packing device promote to downwardly bend the air-packing device, thereby widely opening the top opening for installing a product therein or removing the product therefrom. 
   The air-packing device made of the first and second thermoplastic films with the air containers and air cells is first produced in a sheet like form, and is then folded in a predetermined manner and bonded at predetermined locations to create a three dimensional shape for packing a particular product therein. 
   According to the present invention, the air-packing device forms a flap portion that allows a user to easily enlarge the opening of the air-packing device for placement and removal of the package to be protected. The structure of the air-packing device under the present invention allows to securely hold the package in the air-packing device. Reliability is improved due to check valves that are provided to each air container. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic perspective view showing an example of basic structure of an air-packing device in the conventional technology. 
       FIG. 2  is a plan view of the air-packing device  20  of  FIG. 1  when it is not inflated for showing bonding areas for closing two thermoplastic films. 
       FIGS. 3A and 3B  are perspective views showing an example of structure of the air-packing device of the present invention where  FIG. 3A  shows air-packing device without a product and  FIG. 3B  shows the air-packing device in which a product to be protected is placed therein. 
       FIGS. 4A and 4B  are front view showing the situation for opening the top of the air-packing device of the present invention where  FIG. 4A  shows the steady state thereof without a product therein and  FIG. 4B  shows the situation where flaps are opened for placing the product therein and taking out the product therefrom. 
       FIGS. 5A and 5B  are top views showing an example of structure of the air-packing device of the present invention where  FIG. 5A  shows the air-packing device without the product and  FIG. 5B  shows the air-packing device having the product to be protected therein. 
       FIG. 6  is a plan view showing a sheet form of the air-packing device of the present invention which is not inflated and is not folded or bonded to form the structure shown in  FIGS. 3A-3B ,  4 A- 4 B and  5 A- 5 B. 
       FIGS. 7A-7D  are cross sectional front views showing the process for forming the air-packing device from the sheet form shown in  FIG. 6  to the form of  FIGS. 3A-3B ,  4 A- 4 B and  5 A- 5 B by folding and bonding the predetermined portions of the air-packing device where the air-packing device in  FIGS. 7A-7D  is not inflated by the air. 
       FIGS. 8A-8C  are perspective views showing another embodiment of the air-packing device of the present invention where the air-packing device is closed in  FIG. 8A , the air-packing device is opened for installing or removing the product in  FIG. 8B , and the product is packed in the air-packing device in  FIG. 8C . 
       FIG. 9  is a top view showing the outer structure of the embodiment of the air-packing device of  FIGS. 8A-8C  in accordance with the present invention. 
       FIG. 10  is a plan view showing a sheet form of the air-packing device of the present invention which is not inflated and is not folded of bonded to form the structure shown in  FIGS. 8A-8C  and  9 . 
       FIGS. 11A-11D  are cross sectional front views showing the process for forming the air-packing device from the sheet form shown in  FIG. 10  to the form of  FIGS. 8A-8C  and  9  by folding and bonding the predetermined portions of the air-packing device where the air-packing device in  FIGS. 11A-11D  is not inflated by the air. 
       FIGS. 12A-12B  are diagrams showing an example of detailed structure and operation of the check-valve in the present invention where  FIG. 12A  shows a cross sectional plan view of the check valve,  FIG. 12B  shows a cross sectional side view thereof. 
       FIG. 13  shows a cross sectional side view of the air-packing device at the portion of the check valve for explaining the operation of the check valve. 
       FIGS. 14A-14D  show another example of check valve of the present invention where  FIG. 14A  is a plan view showing a structure of a check valve on an air-packing device,  FIG. 14B  is a plan view showing the check valve including flows of air when a compressed air is supplied thereto,  FIG. 14C  is a plan view showing the portions for bonding the check valve sheet to a thermoplastic film of the air-packing device, and  FIG. 14D  is a plan view showing the portions for bonding the check valve sheet and the two plastic films of the air-packing device. 
       FIG. 15  is a cross sectional view showing an example of inner structure of the check valve in the present invention configured by a single layer film and formed on one of the thermoplastic films of the air-packing device. 
       FIG. 16  is a cross sectional view showing another example of the inner structure of the check valve in the present invention configured by double layer films and formed on one of the thermoplastic films of the air-packing device. 
       FIGS. 17A and 17B  are cross sectional views showing the inner structure of a check valve of the present invention where  FIG. 17A  shows air flows in the air cells of the air-packing device when being inflated, and  FIG. 17B  shows a situation where the air-packing device is fully inflated and the check valve is closed. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The air-packing device of the present invention will be described in more detail with reference to the accompanying drawings. It should be noted that although the present invention is described for the case of using an air for inflating the air-packing device for an illustration purpose, other fluids such as other types of gas or liquid may also be used. The air-packing device is typically used in a container box to pack a product during the distribution channel of the product. 
   A first embodiment of the air-packing device according to the present invention is described with reference to  FIG. 3A-3B ,  4 A- 4 B,  5 A- 5 B,  7  and  7 A- 7 D. This embodiment of the air-packing device can be advantageously used to pack a product having a substantially flat box shape, such as a notebook computer, a DVD player, etc. The air-packing device of the present invention is designed to have a top opening which allows easily opening and closing operations for installing or removing the product to be protected through the top opening. 
     FIG. 3A  is a perspective view of an air-packing device  101  which is inflated by the compressed air but a product to be protected is not placed therein. The air-packing device  101  has a top opening  131  through which a product or a package having the product is introduced to the inner space.  FIG. 3A  shows the situation where the air-packing device is slightly opened at the top from the steady state. 
   Typically, the air-packing device  101  is configured by a plurality of air-containers where each air-container has a plurality of air cells  125   a - 125   g  connected in series. The air-packing device  101  is first produced in a sheet like form as shown in  FIG. 6  and is folded and bonded through the process of  FIGS. 7A-7D . Then, by supplying the compressed air, the air-packing device is inflated to a generally cubic shape of  FIG. 3A  for packing the product therein. 
   Reference is now made to a plan view of  FIG. 6  which shows a sheet like form of the uninflated air-packing device  101  to describe its overall structure and components thereof. The air-packing device  101  is created by bonding two sheets of thermoplastic films. Each of the thermoplastic films is typically made of three layers of materials: polyethylene, nylon and polyethylene which are bonded together with appropriate adhesive. The nylon is provided between the polyethylene to increase the physical strength of the thermoplastic film. 
   The two thermoplastic films are bonded (heat-sealed) at separation seals  129 , side seals  127 , and the heat-seal lands  121  shown in  FIG. 6 . The separation seals  129  air-tightly separate the thermoplastic films to create a plurality of air containers  125  each having a check valve  42 . In a later heat-seal process for forming the three dimensional structure of the air-packing device, the side seals  127  are further heat-sealed at bonding (heat-seal) areas  127   a  and  127   b  after folding the air-packing device  101  in the manner shown in  FIGS. 7A-7D . 
   In this example, the check valve  42  is formed at the left end of each air container  125  where an air input  63  is commonly connected to all of the check valves  42  to supply the compressed air. The check valve  42  is an air valve that prevents reverse flow of the compressed air. Since the check valve  42  is provided to each air container  125 , the air containers  125  of the air-packing device  101  can hold the air (fluid) independently from each other. 
   A plurality of heat-seal lands  121   a - 121   f  are provided within each air container  125  so that the two thermoplastic films of each air container are bonded to one another. Thus, each of the heat-seal lands  121   a - 121   f  partially blocks the flow of air, although the air can pass through the space at both sides of the heat-seal land  121  within the same air container. As a result, each air container  125  is partially separated by the heat-seal lands  121   a - 121   f  to create a plurality of air cells  125   a - 125   g  which has a sausage like shape when inflated by the compressed air. 
   Since the two thermoplastic films are bonded at each of the heat-seal lands  121   a - 121   f  so that the thermoplastic films at the heat-seal lands  121   a - 121   f  will not inflate, the heat-seal lands  121   a - 121   f  are used for folding the air packing device  101  to a desired shape. As noted above, since each strip of the air container  125  has its own check valve  42 , the air containers  125   a - 125   g  are independent from one another. That is, even if one air container  125  is punctured, the other air containers  125   a - 125   g  are not affected, thereby improving reliability of the air packing device  101 . The check valve  42  that can be advantageously implemented in the present invention will be described later in detail with reference to  FIGS. 12A-17B . 
   As noted above, each heat-seal land  121  divides the air container  125  to create a plurality of air cells  125   a - 125   g . For example, with respect to each air container  125 , the heat-seal land  121   a  forms the air cell  125   a , the heat-seal land  121   b  forms the air cell  125   b , and the heat-seal land  121   c  forms the air cell  125   c , and so forth. The sheet like form of the air-packing device  101  is folded and a heat-seal process is conducted to bond predetermined portions thereof for creating a three dimensional structure of  FIGS. 3A-3B ,  4 A- 4 B and  5 A- 5 B. 
   Referring back to  FIG. 3A , the inflated air packing device  101  has a box-like shape with an opening  131 , through which the product to be protected is inserted or removed. As noted above, since the thermoplastic films are bonded at the heat-seal lands  121 , the air-packing device  101  are easily folded at the heat-seal lands  121  as folding points.  FIG. 3A  shows the condition where the air-packing device  101  is forcefully bent at both sides of the bottom by user&#39;s hands as shown by arrows. As a result, each of the air cells  125   a  and  125  at both ends works as a flap so that the size of the top opening  131  is increased to easily insert the product in an inner space of the air-packing device. 
     FIG. 3B  is a perspective view similar to  FIG. 3A , except that a product  201  to be protected is placed inside of the air packing device  101 , and thus, the bottom is returned to the steady condition. The product  201  is snugly packed within the inner space of the air packing device  101 . In this example, the product  201  has a substantially flat box shape and its outer surfaces contact with the air cells  125   a - 125   g  of the air packing device  101 . Typically, the air-packing device  101  having the product  201  therein is further installed in a container box, made of hard paper, corrugated fiber board, etc., commonly used in the industry. Therefore, the product  201  is protected from the shock and vibration. 
     FIGS. 4A and 4B  are front views of the inflated air-packing device  101  of the present invention.  FIG. 4A  shows the condition where the top opening  131  of the air packing device  101  is “closed” in the steady state.  FIG. 4B  shows the condition wherein the top opening  131  of the air packing device  101  is “opened” for installation or removal of the product. In this example, the left side of the air-packing device  101  is configured by the air cells  125   a ,  125   b , and  125   c , and the right side of the air packing device  101  comprises the air cells  125   g ,  125   f , and  125   e  where the bottom portion is connected by the air cell  125   d.    
   As shown in  FIG. 4B , when increasing the size of the top opening  131 , the heat-seal lands  121   c  and  121   d  at the bottom allow user to easily bend the air-packing device  101  downwardly as the folding points. As a result, the air-packing device  101  is widened at the top opening  131  to easily place a product to be protected therein or to easily take out the product therefrom. Thus, the air-packing device  101  is able to hold the package securely while allowing easy placement and removal of the product. 
     FIGS. 5A and 5B  are top views showing the structure of the air-packing device  101  of the present invention which is inflated by the compressed air.  FIG. 5A  shows the condition where the air-packing device  101  does not contain a product to be protected therein such as shown in  FIG. 3A .  FIG. 5B  shows the condition where the air-packing device  101  contains a product  201  to be protected therein such as show in  FIG. 3B . 
   As noted above, the sheet like form of the air-packing device  101  shown in  FIG. 6  is folded and a heat-seal process is conducted to bond the predetermined portions of the air-packing device  101  for creating the three dimensional structure of  FIGS. 3A-5B . Such a procedure of folding and bonding the sheet of the air-packing device  101  of  FIG. 6  is explained with reference to  FIGS. 7A-7D .  FIGS. 7A-7D  are schematic cross sectional front views of the air-packing device  101  before being inflated by the compressed air. In  FIGS. 7A-7D , the check valves  42  are omitted for simplicity of illustration. 
     FIG. 7A  shows the condition where the sheet form of the air-packing device  101  lies flat.  FIG. 7B  shows the condition where the air packing device  101  is folded at the heat-seal lands  121   a ,  121   b ,  121   f  and  121   e . The heat-seal lands  121   c  and  121   d  are straight and not bent unlike other heat-seal lands. In reality, since the air-packing device  101  is not inflated, it can be bent in any form without regard to the locations of the heat-seal lands  121 . However, it should be noted that, to show the relationship between the folding process and the final structure of the air-packing device  101 , shapes (ex. bending points) shown  FIGS. 7A-7D  are exaggerated. 
     FIG. 7C  shows the condition where the air-packing device  101  is further bent at the middle section of the air cells  125   b  and  125   f .  FIG. 7D  shows the condition where the air-packing device  101  is completely bent flatly to perform a heat-seal process. When folded in the manner of  FIG. 7D , the heat-seal areas  127   a  (see also  FIG. 6 ) at each side of the air-packing device  101  are bonded with each other in such a way that the heat-seal area  127   a  extending along the sidemost air cells  125   a ,  125   b  and  125   c  is bonded. Similarly, the heat-seal areas  127   b  (see also  FIG. 6 ) at each side of the air-packing device  101  are bonded with each other in such a way that the heat-seal area  127   b  extending along the sidemost air cells  125   g ,  125   f  and  125   e  is bonded. 
   Therefore, a pocket like space is created at each of the left end and the right end of the air-packing device  101 . Preferably, an end portion of the air cells  125   a  (flap portion) and an end portion of the air cells  125   g  (flap portion) are not bonded in the above heat-sealing process so that the end portions promote to easily open the air-packing device  101  as shown in  FIG. 4B . When the air packing device  101  shown in  FIG. 7D  is inflated by supplying the compressed air, the air packing device  101  takes the form shown in  FIGS. 3A-3B ,  4 A- 4 B and  5 A- 5 B. 
   It should be noted that the number of the air containers  125  and the number of air cells  125   a - 125   g  for each air container may vary to better accommodate a particular product to be protected. In the foregoing example, the flap portions (air cells  125   a  and  125   g ) cover a part of the product shown in  FIG. 5B  and has a relatively large opening at the top of the air-packing device  101 . However, the size of the flap portion (air cells  125   a  and  125   g ) for forming the top opening  131  can be changed such that a whole product will be enclosed by the air-packing device  101 . 
   A second embodiment of the air packing device under the present invention is explained next with reference to  FIGS. 8A-8C ,  9 ,  10  and  11 A- 11 D. The second embodiment is suited for packing a product having a generally cylindrical shape such as a bottle although it can effectively pack other product as well. In the second embodiment, the air-packing device  201  is configured to have a top opening in a manner similar to the first embodiment. However, the air-packing device  201  in the second embodiment has one long flap portion where an end of the flap portion is configured to fit-in the top opening of the air-packing device  201 . 
     FIG. 8A  is a perspective view showing the second embodiment of the air-packing device of the present invention where the air-packing device  201  is closed. The air-packing device  201  is configured by a plurality of air-containers where each air-container has a plurality of air cells  225   a - 225   f  connected in series. In  FIG. 8A , the air-packing device  201  is closed, in  FIG. 8B , the air-packing device  201  is opened for installing or removing the product, and in  FIG. 8C , a product such as a bottle is packed in the air-packing device  201 . In this example, a flap portion for opening and closing the air-packing device  201  is mainly comprised of the air cells  225   a.    
   Typically, the air-packing device  201  is configured by a plurality of air-containers where each air-container has a plurality of air cells  225   a - 225   f  connected in series. The air-packing device  201  is first produced in a sheet like form as shown in  FIG. 10  and is folded and bonded through the process of  FIGS. 11A-11D . Then, by supplying the compressed air, the air-packing device  201  is inflated to a generally cylindrical shape of  FIGS. 8A-8C  for packing the product therein. 
     FIG. 10  is a top view showing an example of structure of the second embodiment of the air-packing device  201  in a sheet like form before being folded or inflated to form a three dimensional structure of  FIGS. 8A-8C . Similar to the air packing device  101  in the first embodiment described above, the air-packing device  201  is created by bonding the two sheets of thermoplastic films. Each of the thermoplastic films is typically made of three layers of materials: polyethylene, nylon and polyethylene which are bonded together with appropriate adhesive. The nylon is provided between the polyethylene to increase the physical strength of the thermoplastic film. 
   The two thermoplastic films are bonded (heat-sealed) at separation seals  229 , side seals  227 , and the heat-seal lands  221  as shown in  FIG. 10 . The separation seals  229  air-tightly separate the thermoplastic films to create a plurality of air containers  225  each having a check valve  42  and air cells  225   a - 225   f . In a later heat-seal process for forming the three dimensional structure of the air-packing device, the side seals  227  are further heat-sealed at bonding (heat-seal) areas  227   a  and  227   b  after folding the air-packing device  201  in the manner shown in  FIGS. 11A-11D . 
   In this example, the check valve  42  is formed at the left end of each air container  225  where an air input  63  is commonly connected to all of the check valves  42  to supply the compressed air. The check valve  42  is an air valve that prevents reverse flow of the compressed air. Since the check valve  42  is provided to each air container  225 , the air containers  225  of the air-packing device  201  can hold the air (fluid) independently from each other. 
   A plurality of heat-seal lands  221   a - 221   e  are provided within each air container  225  so that the two thermoplastic films of each air container are bonded to one another. Thus, each of the heat-seal lands  221   a - 221   e  partially blocks the flow of air, although the air can pass through the space at both sides of the heat-seal land  221  within the same air container. As a result, each air container  225  is partially separated by the heat-seal lands  221   a - 221   e  to create a plurality of air cells  225   a - 225   f  which has a sausage like shape when inflated by the compressed air. 
   Since the two thermoplastic films are bonded at each of the heat-seal lands  221   a - 221   e  so that the thermoplastic films at the heat-seal lands  221   a - 221   e  will not inflate, the heat-seal lands  221   a - 221   e  are used for folding the air packing device  201  to a desired shape. As noted above, since each strip of the air container  225  has its own check valve  42 , the air containers  225   a - 225   f  are independent from one another. That is, even if one air container  225  is punctured, the other air containers  225   a - 225   f  are not affected, thereby improving reliability of the air packing device  201 . The check valve  42  that can be advantageously implemented in the present invention will be described later in detail with reference to  FIGS. 12A-17B . 
   As noted above, each heat-seal land  221  divides the air container  225  to create a plurality of air cells  225   a - 225   f . For example, with respect to each air container  225 , the heat-seal land  221   a  forms the air cell  225   a , the heat-seal land  221   b  forms the air cell  225   b , and the heat-seal land  221   c  forms the air cell  225   c , and so forth. The sheet like form of the air-packing device  201  shown in  FIG. 10  is folded and a heat-seal process is conducted to bond predetermined portions thereof for creating a three dimensional structure of  FIGS. 8A-8C . 
   As shown in  FIG. 8B , when the flap portion (air cells  225   a ) is opened, the heat-seal lands  221   c  at the bottom left allow the user to easily bend the air packing device  201  downwardly at the bottom. In this example, since the air cells  225  (flap portion) are long enough to extend from the left end to the right side of the air packing device  201 , when in the “open” condition, it creates an elongated opening at the top between the air cells  225  and the air cells  225   f . As a result, the user can easily insert the product in the air-packing device  201  or remove the product from the air-packing device  201 . 
     FIG. 8C  shows the condition where a product to be protected, such as a wine bottle  261 , is placed in the inner space of the air-packing device  201 . As shown in  FIG. 8B , the user can fully open the air-packing device  201  easily by opening the air cells  225   a  while downwardly bending the bottom left portion (heat-seal lands  221   c ) to install the bottle  261 . Then, the flap portion comprising the air cells  225   a  is closed as shown in  FIG. 8C . 
   Preferably, the flap portion (air cells  225   a ) is designed to be long enough such that an end thereof can come inside of the air-packing device  201  under the air-cells  225   f . Since the end of the flap portion comes inside of the air-packing device  201 , i.e., a part of the air cells  225   a  comes underneath the air cells  225   f , it is possible to securely pack the product  261  therein. Typically, the air-packing device  201  having the product  261  therein is further installed in a container box, made of hard paper, corrugated fiber board, etc., commonly used in the industry. In this manner, the product  261  is fully protected from the shock and vibration. 
     FIG. 9  is a top view showing the inflated air packing device  201  under the present invention. This view shows the condition wherein the flap is closed. As noted above, the right end of the air cells  225   a  is inserted in the top opening, i.e., it is located under the air cells  225   f  to firmly close the air-packing device  201 . Compared to the top view shown in  FIG. 5A , the air packing device  201  has long sideways with fewer air containers to create the generally cylindrical shape. Moreover, unlike the symmetrical shape of the air-packing device  101  which has a pair of flap portions, only one flap portion made of the air cells  225   a  functions to open and close the air-packing device  201 . 
   As noted above, the sheet like form of the air-packing device  201  shown in  FIG. 10  is folded and a heat-seal process is conducted to bond predetermined portions of the air-packing device  201  for creating the three dimensional structure of  FIGS. 8A-9 . Such a procedure of folding and bonding the sheet of the air-packing device  201  of  FIG. 10  is explained with reference to  FIGS. 11A-11D .  FIGS. 11A-11D  are schematic cross sectional front views of the air-packing device  201  before being inflated by the compressed air. In  FIGS. 11A-11D , the check valves  42  are omitted for simplicity of illustration. 
     FIG. 11A  shows the condition where the sheet form of the air-packing device  201  lies flat.  FIG. 11B  shows the condition where the air packing device  201  is folded at the heat-seal lands  221 . In reality, since the air-packing device  201  is not inflated, it can be bent in any form without regard to the locations of the heat-seal lands  221 . However, it should be noted that, to show the relationship between the folding process and the final structure of the air-packing device  201 , shapes (ex. bending points) shown  FIGS. 11A-11D  are exaggerated. 
     FIG. 11C  shows the condition where the air-packing device  201  is further bent at the middle section of the air cells  225   b  and  225   e .  FIG. 11D  shows the condition where the air-packing device  201  is completely bent flatly to perform a heat-seal process. When folded in the manner of  FIG. 11D , the heat-seal areas  227   a  (see also  FIG. 10 ) at each side of the air-packing device  201  are bonded with each other in such a way that the heat-seal area  227   a  extending along the sidemost air cells  225   b  and  125   c  and a small part of the air cells  225   a  is bonded. Similarly, the heat-seal areas  127   b  (see also  FIG. 10 ) at each side of the air-packing device  201  are bonded with each other in such a way that the heat-seal area  227   b  extending along the sidemost air cells  225   f  and  225   e  and a part of the air cells  225   d  is bonded. 
   Therefore, a pocket like space is created at each of the left end and the right end of the air-packing device  201 . The pocket like space in the left is small since the heat-seal areas  227   a  extends only a small portion of the air cells  225   a . Therefore, the flap portion formed by the air cells  225   a  is free from the other portions of the air-packing device  201  to easily open and close the air-packing device  201  as shown in  FIGS. 8A-8C . 
   It should be noted that the number of the air containers  225  and the number of air cells  225   a - 225   f  for each air container may vary to better accommodate a particular product to be protected. In the foregoing example, the flap portion (air cells  225   a ) covers all of the product shown in  FIG. 8C  and the end of the flap portion is locked inside (under the air cells  225   f ) of the air-packing device  201 . However, the size, length, and shape of the flap portion (air cells  225   a ) for forming the top opening can be changed depending on the size and shape of the product to be protected. 
     FIGS. 12A-12B  show example of structure of a check valve that can be implemented in the present invention. In  FIGS. 12A-12B , the check valve is denoted by a numeral  44  and the air container is denoted by a numeral  42 .  FIG. 12A  is a top view of the check valve  44 ,  FIG. 12B  is a cross sectional side view of the check valve  44  taken along the line X-X in  FIG. 12A  when the compressed air is not supplied to the air-packing device, and  FIG. 13  is a cross sectional side view of the check valve  44  when the compressed air is supplied to the air-packing device. 
   In the example of  FIGS. 12A and 12B , reinforcing seal portions  72  are formed near a check valve inlet  63   a . These portions are placed in a manner of contacting each edge of the inlet portion  63   a . The seal portions  72  are provided to reinforce a boundary between the guide passage  63  and the air container  42  so as to prevent the air container from a rupture when it is inflated. In the check valve  44  of the present invention, the reinforcing seal portions  72  are preferable but not essential and thus can be omitted. 
   In the air-packing device, the two check valve films  92   a  and  92   b  are juxtaposed (superposed) and sandwiched between the two air-packing films  91   a  and  91   b  near the guide passage  63 , and fixing seal portions  71 - 72 ,  65  and  67 . The fixing seal portions  71 - 72  are referred to as outlet portions, the fixing seal portion  65  is referred to as an extended (or widened) portion, and the fixing seal portion  67  is referred to as a narrow down portion. These fixing seal portions also form the structure of the check valve  44  and fix the valve to the first air-packing film  91   a  at the same time. The fixing seal portions  65  are made by fusing the check valve films  92   a  and  92   b  only with the first air-packing film  91   a.    
   The check valve  44  is made of the two check valve films (thermoplastic films)  92   a - 92   b  by which an air pipe (passage)  78  is created therebetween. How the air passes through the check valve  44  is shown by arrows denoted by the reference numbers  77   a ,  77   b  and  77   c  in  FIG. 12A . The compressed air is supplied from the guide passage  63  through the air pipe  78  to the air container  42 . 
   In the check valve  44 , the regular air relatively easily flows through the air pipe  78  although there exist the fixing seal portions  65 ,  67  and  71 - 72 . However, the reverse flow of the air in the valve will not pass through the air pipe  78 . In other words, if the reverse flow occurs in the air pipe  78 , it is prevented because of a pressure of the reverse flow itself. By this pressure, the two surfaces of check valve films  92   a  and  92   b  which face each other, are brought into tight contact as shown in  FIG. 13  as will be explained later. 
   As has been described, in  FIGS. 12A-12B , the fixing seal portions  65 ,  67  and  71 - 72  also work for guiding the air to flow in the check valve  44 . The fixing seal portions are comprised of the portions  71   a ,  72   a ,  65   a  and  67   a  which bond the two check-valve films  92   a  and  92   b  together, and the portions  71   b ,  72   b ,  65   b  and  67   b  which bond the first air-packing film  91   a  and the first check valve film  92   b  together. Accordingly, the air pipe  78  in the check valve  44  is created as a passage formed between the two check valve films  92   a - 92   b.    
   Further in  FIG. 12A , the fixing seal portions  67  are composed of two symmetric line segments extended in an upward direction of the drawing, and a width of the air pipe  78  is narrowed down by the fixing seal portions (narrow down portions)  67 . In other words, the regular flow can easily pass through the air pipe  78  to the air container  42  when passing through the wide space to the narrow space created by the narrow down portions  67 . On the other hand, the narrow down potions  67  tend to interfere the reverse flow from the air containers  42  when the air goes back through the narrow space created by the narrow down portions  67 . 
   The extended portion  65  is formed next to the narrow down portions  67 . The shape of the extended portion  65  is similar to a heart shape to make the air flow divert. By passing the air through the extended portion  65 , the air diverts, and the air flows around the edge of the extended portion  65  (indicated by the arrow  77   b ). When the air flows toward the air container  42  (forward flow), the air flows naturally in the extended portion  65 . On the other hand, the reverse flow cannot directly flow through the narrow down portions  67  because the reverse flow hits the extended portion  65  and is diverted its direction. Therefore, the extended portion  65  also functions to interfere the reverse flow of the air. 
   The outlet portions  71 - 72  are formed next to the extended portion  65 . In this example, the outlet portion  71  is formed at the upper center of the check valve  44  in the flow direction of the air, and the two outlet portions  72  extended to the direction perpendicular to the outlet portion  71  are formed symmetrically. There are several spaces among these outlet portions  71  and  72 . These spaces constitute a part of the air pipe  78  through which the air can pass as indicated by the arrows  77   c . The outlet portions  71 - 72  are formed as a final passing portion of the check valve  44  when the air is supplied to the air container  42  and the air diverts in four ways by passing through the outlet portions  71 - 72 . 
   As has been described, the flows of air from the guide passage  63  to the air containers  42  is relatively smoothly propagated through the check valve  44 . Further, the narrow down portions  67 , extended portions  65  and outlet portions  71 - 72  formed in the check valve  44  work to interfere the reverse flow of the air. Accordingly, the reverse flow from the air containers  42  cannot easily pass through the air pipe  78 , which promotes the process of supplying the air in the air-packing device. 
     FIG. 13  is a cross sectional view showing an effect of the check valve  44  of the present invention. This example shows an inner condition of the check valve  44  when the reverse flow tries to occur in the air-packing device when it is sufficiently inflated. First, the air can hardly enter the air pipe  78  because the outlet portions  71  and  72  work against the air such that the reverse flow will not easily enter in the outlet portions. Instead, the air flows in a space between the second air-packing film  91   b  and the second check valve film  92   a  as indicated by the arrows  66 , and the space is inflated as shown in  FIG. 13 . By this expansion, in  FIG. 13 , the second check valve film  92   a  is pressed to the right, and at the same time, the first check valve film  92   b  is pressed to the left. As a result, the two check valve films  92   a  and  92   b  are brought into tight contact as indicated with the arrows  68 . Thus, the reverse flow is completely prevented. 
   Another example of the check valve of the present invention is described in detail with reference to  FIGS. 14A-14D ,  15 - 16  and  17 A- 17 B in which a check valve is denoted by a reference numeral  85 .  FIGS. 14A-14D  are plan views of the check valve used in the air-packing devices of the present invention.  FIG. 14A  shows a structure of a check valve  85  and a portion of the air-packing device. The air-packing device having the check valves  85  is comprised of two or more rows of air container each having serially connected air cells  83  which are equivalent to the air cells  125  and  225  in  FIGS. 3A-11D . As noted above, typically, each row of air container has a plurality of series connected air cells  83  although only one air cell is illustrated in  FIGS. 14A-14D . 
   Before supplying the air, the air-packing device is in a form of an elongated rectangular sheet made of a first (upper) thermoplastic film  93  and a second (lower) thermoplastic film  94 . To create such a structure, each set of series air cells are formed by bonding the first thermoplastic film (air packing film)  93  and the second thermoplastic film (air packing film)  94  by the separation seal (bonding area)  82 . Consequently, the air cells  83  are created so that each set of series connected air cells can be independently filled with the air. 
   A check valve film  90  having a plurality of check valves  85  is attached to one of the thermoplastic films  93  and  94  as shown in  FIG. 14C . When attaching the check valve film  90 , peeling agents  87  are applied to the predetermined locations on the separation seals  82  between the check valve film  90  and one of the thermoplastic films  93  and  94 . The peeling agent  87  is a type of paint having high thermal resistance so that it prohibits the thermal bonding between the first and second thermoplastic films  93  and  94 . Accordingly, even when the heat is applied to bond the first and second thermoplastic films  93  and  94  along the separation seal  82 , the first and second thermoplastic films  93  and  94  will not adhere with each other at the location of the peeling agent  87 . 
   The peeling agent  87  also allows the air input  81  to open easily when filling the air in the air-packing device  130 . When the upper and lower films  93  and  94  made of identical material are layered together, there is a tendency that both films stick to one another. The peeling agent  87  printed on the thermoplastic films prevents such sticking. Thus, it facilitates easy insertion of an air nozzle of the air compressor into the air inlet  81  when inflating the air-packing device. 
   The check valve  85  of the present invention is configured by a common air duct portion  88  and an air flow maze portion  86 . The air duct portion  88  acts as a duct to allow the flows of the air from the air port  81  to each set of air cells  83 . The air flow maze portion  86  prevents free flow of air between the air-packing device  130  and the outside, i.e., it works as a brake against the air flows, which makes the air supply operation easy. To achieve this brake function, the air flow maze portion  86  is configured by two or more walls (heat-seals)  86   a - 86   c . Because of this structure, the air from the common air duct portion  88  will not straightly or freely flow into the air cells  83  but have to flow in a zigzag manner. At the and of the air flow maze portion  86 , an exit  84  is formed. 
   In the air-packing device incorporating the check valve  85  of the present invention, the compressed air supplied to the air input  81  to inflate the air cells  83  flows in a manner as illustrated in  FIG. 14B . The plan view shown in  FIG. 14B  includes the structure of the check valve  85  identical to that of  FIG. 14A  and further includes dotted arrows  89  showing the flows of the air in the check valve  85  and the air cells  83 . As indicated by the arrows  89 , the air from the check valve  85  flows both forward direction and backward direction of the air-packing device. Thus, the check valve  85  can be formed at any locations of the air-packing device. Further, the check valve  85  requires a relatively low pressure of the air compressor when it is attached to an intermediate location of the air-packing device. 
   In  FIG. 14B , when the air is supplied to the air input  81  from the air compressor (not shown), the air flows toward the exit  84  via air duct portion  88  and the air flow maze portion  86  as well as toward the next adjacent air cell  83  via the air duct portion  88 . The air exited from the exit  84  inflates the air cell  83  by flowing both forward and backward directions (right and left directions of  FIG. 14B ) of the air-packing device. The air transferred to the next air cell flows in the same manner, i.e., toward the exit  84  and toward the next adjacent air cell  83 . Such operations continue from the first air cell  83  to the last air cell  83 . In other words, the air duct portion  88  allows the air to flow to either the present air cell  83  through the air flow maze portion  86  and to the next air cell  83 . 
     FIGS. 14C-14D  show an enlarged view of the check valve of the present invention for explaining how the check valves  85  are created on the air-packing device. As noted above, the check valve film  90  is attached to either one of the thermoplastic film  93  or  94 . The example of  FIGS. 14C and 14D  show the case where the check valve film  90  is attached to the upper (first) thermoplastic film  93 . The thick lines in the drawings indicate the heat-seal (bonding) between the thermoplastic films. 
   The air-packing device of the present invention is manufactured by bonding the second (lower) thermoplastic film  94 , the check valve film  90 , and the first (upper) thermoplastic film  93  by pressing the films with a heater. Since each film is made of thermoplastic material, they will bond (welded) together when the heat is applied. In this example, the check valve film  90  is attached to the upper thermoplastic film  93 , and then, the check valve film  90  and the upper thermoplastic film  93  are bonded to the lower thermoplastic film  94 . 
   First, as shown in  FIG. 14C , the check valve film  90  is attached to the upper thermoplastic film  93  by heat-sealing the two films at the portions indicated by the thick lines. Through this process, the peeling agents  87  applied in advance to the check valve film  90  is attached to the upper thermoplastic film  93  by the bonding lines  79   a  and  79   b  to create the air duct portions  88 . Further, the air flow maze portions  86  are created by the bonding lines  86   a - 86   c , etc. At the end of the maze portion  86  is opened to establish the air exit  84 . 
   Then, as shown in  FIG. 14D , the check valve film  90  and the upper thermoplastic film  93  are attached to the lower thermoplastic film  94  by heat-sealing the upper and lower films at the portions indicated by the thick lines  82 . Through this process, each air cell  83  is separated from one another because the boundary between the two air cells is closed by the sealing line (boundary line)  82 . However, the range of the sealing line  82  having the peeling agent  87  is not closed because the peeling agent prohibits the heat-sealing between the films. As a result, the air duct portion  88  is created which allows the air to flow in the manner shown in  FIG. 14B . 
     FIG. 15  is a partial cross sectional front view showing an example of inner structure of the check valve  85   a  of the present invention configured by a single layer film and formed on a thermoplastic film of the air-packing device. As described in the foregoing, the common air duct portion  88  and the air flow maze portion  86  are created between the check valve film  90  and one of the upper and lower thermoplastic films  93  and  94 . In this example, the check valve film  90  is attached to the upper thermoplastic film  93  through the heat-sealing in the manner described with reference to  FIG. 14C . 
   The air flow maze portion  86  has a maze structure such as a zig-zaged air passage to cause resistance to the air flow such as reverse flow. Such a zig-zaged air passage is created by the bonding (heat-sealed) lines  86   a - 86   c . Unlike the straight forward air passage, the maze portion  86  achieves an easy operation for inflating the air-packing device by the compressed air. Various ways for producing the resistance of the air flow are possible, and the structure of the maze portion  86  shown in  FIGS. 14A-14D  and  15  is merely one example. In general, the more complex the maze structure, the less area of the maze portion  86  is necessary to adequately produce the resistance against the air flow. 
     FIG. 16  is a cross sectional view showing another example of the inner structure of the check valve  85   b  in the present invention configured by double layer films and formed on one of the thermoplastic films of the air-packing device. In this example, an addition film  95  is provided between the upper thermoplastic film  93  and the check valve film  90 . The additional film  95  and the check valve film  90  forms the check valves  85   b . The additional film  95  is so attached to the upper thermoplastic film  93  that the space between the upper thermoplastic film  93  and the additional film  95  will not transmit air. 
   The advantage of this structure is the improved reliability in preventing the reverse flows of air. Namely, in the check valve of  FIG. 15 , when the air is filled in the air cell  83 , the upper thermoplastic film  93  of the air cell having the check valve  85  is curved. Further, when a product is loaded in the air-packing device, the surface projection of the product may contact and deform the outer surface of the air cell having the check valve therein. The sealing effect created by the check valve can be weakened because of the curvature of the air cell. The additional film  95  in  FIG. 16  mitigates this problem since the film  95  is independent from the upper thermoplastic film  93 . 
     FIGS. 17A and 17B  are cross section views showing the inside of the air cell having the check valve  85 .  FIG. 17A  shows the condition wherein the compressed air is being introduced into the air-packing device through the check valve  85 .  FIG. 17B  shows the condition where the air-packing device is filled with air to an appropriate degree so that the check valve  85  is operated to effectively close by the inside air pressure. The dotted arrows  89  indicate the flow of air in  FIGS. 17A and 17B . 
   As shown in  FIG. 17A , when the air is pumped in from the air input  81  ( FIGS. 14A-14B ), the air will flow toward each air cell. While a part of the air flows toward the next row of air cells, the remaining air goes into the present air cell to inflate the air cell. The air will flow into the air cell due to the pressure applied from the air source such as an air compressor. The air goes through the air flow maze portion  86  and exits from the exit  84  at the end of the maze portion  86 . All of the air cells will eventually be filled with the compressed air. 
   As shown in  FIG. 17B , when the air cell having the check valve  85  is inflated to a certain extent, the inner pressure of the air will push the check valve film  90  upward so that it touches the upper thermoplastic film  93 .  FIG. 17B  mainly shows the air flow maze portion  86  of the check valve  85  to show how the check valve  85  works. When the inner pressure reaches a sufficient level, the check valve film  90  air-tightly touches the upper thermoplastic film  93 , i.e., the check valve  85  is closed, thereby preventing the reverse flows of the air. 
   As has been described above, according to the present invention, the air-packing device can minimize the shocks or vibrations to the product when the product is dropped or collided. The air-packing device is comprised of multiple rows of air containers each having a plurality of air cells connected in series. After being inflated by the compressed air, the air-packing device is folded, thereby creating a unique structure which is designed to protect the product. 
   As has been described above, the air-packing device of the present invention forms a flap portion that allows a user to easily enlarge the opening of the air-packing device for placement and removal of the package to be protected. The structure of the air-packing device under the present invention allows to securely hold the package in the air-packing device. Reliability is improved due to check valves that are provided to each air container. 
   Although the invention is described herein with reference to the preferred embodiments, one skilled in the art will readily appreciate that various modifications and variations may be made without departing from the spirit and the scope of the present invention. Such modifications and variations are considered to be within the purview and scope of the appended claims and their equivalents.