Abstract:
In order to provide an air passage structure and an air-filling cushioning material using the same which facilitates an air-supplying operation via an air passage and does not increase in the production costs in comparison with the conventional one. An air passage structure is provided for a bag  1  that is formed with flexible sheets  1   a,    1   b  by adhering the overlapped sheets  1   a,    1   b  at predetermined spots, comprising a closed portion  2  having a space where air can be circulated, and an air passage  3  for passing air between the outside of the bag  1  and the closed portion  2 , wherein the air passage  3  is provided with an enlarged portion  31  having an opening portion  3   a  opened to the outside of the bag  1 , and the enlarged portion  31  is formed by enlargement of the air passage  3  by deforming at least one of the sheets.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to, in an air-filling cushioning material for packing so as to prevent damaging an article to be protected, an air passage structure and an air-filling cushioning material using the same.  
         [0003]     2. Description of Background Art  
         [0004]     Conventionally, an air-filling cushioning material manufactured by overlapping soft resin sheets and forming an air-filling portion having a space where air can be filled between the sheets has been widely used. By bringing the whole or part of the article to be protected in contact with the air-filling portion of the air-filling cushioning material, the article can be protected against an external shock.  
         [0005]     As an example of such an air-filling cushioning material as described above, an air-filling cushioning material by the applicant of the present application as disclosed in Japanese Published Unexamined Patent Application No. H07-285581 exists. Like the air-filing cushioning material shown in  FIG. 1 , cells of air-filling portions in this cushioning material are the same in a planar view are formed in a sectioned manner by adhering airtight soft resin sheets. An article brought in contact with the air-filling cushioning material is protected by a cushioning effect of the cells where air is filled.  
         [0006]     Herein, the cells are plurally formed in parallel, and an air passage is formed at one side end thereof so as to be orthogonal to the respective cells. This air passage is closed at one side end in the longitudinal direction and is opened at the other side end.  
         [0007]     Accordingly, air can be supplied through a nozzle inserted into this opening end portion and filled in the cells via the air passage.  
         [0008]     This conventional air passage is, however, a flat air passage formed by one and the other sheets constituting an air-filling cushioning material. It is necessary to have a space between the overlapped sheets by separating them in inserting an air-supplying nozzle into the opening end portion of the air passage. In the case the sheets closely contact, the supply of air can be hindered, causing a decline in production efficiency.  
         [0009]     In order to prevent such a situation, a cylindrical body made of a hard resin or the like is disposed at the opening end portion of the air passage in some cases. Although the supply of air into the air passage can be easily carried out in comparison with the above-described case, attachment of a cylindrical body like that may increase the production costs and is not preferable in the end.  
       SUMMARY AND OBJECTS OF THE INVENTION  
       [0010]     In view of the above-described problem, it is an object of the present invention to provide an air passage structure and an air-filling cushioning material using the same which facilitates the supply of air into an air passage and leads to a decrease in the production costs in comparison with the conventional one.  
         [0011]     In order to achieve the above-described object, an aspect of the present invention according to claim  1  provides an air passage structure provided for a bag  1  that is formed with flexible sheets  1   a ,  1   b  by adhering the overlapped sheets  1   a ,  1   b  at predetermined spots, comprising a closed portion  2  having a space where air can be circulated, and an air passage  3  for passing air between the outside of the bag  1  and the closed portion  2 . The air passage  3  is provided with an enlarged portion  31  having an opening portion  3   a  opened to the outside of the bag  1 . The enlarged portion  31  is formed by enlargement of the air passage  3  by deforming at least one of the sheets.  
         [0012]     Also, an aspect of the present invention according to claim  2  provides an air passage structure provided for a bag  1  that is formed with flexible sheets  1   a ,  1   b  by adhering the overlapped sheets  1   a ,  1   b  at predetermined spots, comprising a closed portion  2  having a space where air can be circulated, and an air passage  3  for passing air between the outside of the bag  1  and the closed portion  2 . The air passage  3  is provided with an enlarged portion  31  having an opening portion  3   a  opened to the outside of the bag  1  and a flat portion  32 . The enlarged portion  31  and the flat portion  32  are situated from the opening portion  3   a  in this order. And, viewing a cross sectional shape of the air passage  3 , the side length L2 of the enlarged portion  31  is formed longer than the side length L1 of the flat portion  32 .  
         [0013]     The “side length” referred hereinto in the present invention as claimed in the application means, in the air passage  3  on which seals  4  have been formed by heat-sealing or the like to form the sheets in a sectioned manner, a path length along the sheets between one seal  4  and the other seal  4 .  
         [0014]     In addition, an aspect of the present invention according to claim  3  provides the air passage structure as set forth in claim  1  or  2 , wherein, viewing a cross sectional shape of the air passage  3 , the side length L2 of the other sheet  1   b  is formed longer than the side length L3 of the one sheet  1   a  where the enlarged portion  31  of the air passage  3  is constituted.  
         [0015]     Further, an aspect of the present invention according to claim  4  provides an air-filling cushioning material having the air passage  3  as set forth in any of claims  1  through  3 , wherein a closed portion  2  is composed of a plurality of cells formed in a manner so as to be in parallel. And the respective cells  21  are formed so as to branch off in a direction to cross the air passage  3  and have a space closed except for a communicating portion  5  that communicates with the air passage  3 . The communicating portion  5  is provided with a check valve  51  for permitting an air-flow from the air passage  3  to the cells  21  and checking an air-flow in a reverse direction. The respective cells  21  are filled with air supplied from an opening portion  3   a  via the air passage  3 , thus producing a cushioning effect to an article which is brought into contact with the inflated cells  21 .  
         [0016]     The present invention as claimed in the application can provide an air passage structure, wherein an opening portion  3   a  is provided at an enlarged portion  31  formed by enlarging the air passage  3 , thus the supply of air from the enlarged portion  3   a  into the air passage  3  is efficient. Moreover, since the air-filling cushioning material  1 , contrary to the conventional one, does not need to be disposed with a cylindrical body made of a hard resin or the like at the opening portion  3   a , the production costs will not increase.  
         [0017]     Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
     
    
     DESCRIPTION OF THE DRAWINGS  
       [0018]     The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings, which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:  
         [0019]      FIG. 1  is a plan view showing an air-filling cushioning material;  
         [0020]     FIGS.  2 (A) to  2 (C) are explanatory drawings of sectional views exemplifying the shapes of an enlarged portion of an air passage, and  FIG. 2 (D) is an explanatory drawing of a sectional view exemplifying the shape of a flat portion of the air passage. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0021]     Hereinafter, an air-filling cushioning material with an air passage structure according to an embodiment of the present invention will be described together with the drawings.  
         [0022]     For the material of an air-filling cushioning material  1  of this invention, used are airtight sheets  1   a ,  1   b  which are deformable in response to the later-described cells  21  (a closed portion  2 ) when air is filled therein. In the present embodiment, soft resin sheets, concretely, two flat sheets of a multi-layer structure by way of sticking polyethylene, non-stretch nylon or the like together are used.  
         [0023]     These sheets  1   a ,  1   b  being overlapped, seals  4  are formed thereon at a plurality of spots by means of heat-sealing or the like, whereby a closed portion  2  having a space where air can be circulated is formed. In the present embodiment, as shown in  FIG. 1 , a plurality of cells  21  paralleled in the horizontal direction are formed as a closed portion  2 . And, together with an air passage  3  positioned above the cells  21  and communicating with the cells  21 , a planar air-filling cushioning material  1  is formed.  
         [0024]     The cells  21  formed in the present embodiment as shown in  FIG. 1  are strip-like cells that are long and thin in the vertical direction and are adjacent to each other in the horizontal direction. However, the present invention is not limited to these cells, a single closed portion  2  may be formed without being divided. Also, the shape of the cells  21  is not limited to the illustrated mode. The present invention can be carried out in various modes, such as circular or elliptic connecting cells, or cells  21  which widths are different depending on the position.  
         [0025]     The cell  21  of the present embodiment is opened at its upper end portion of the drawing as a communicating portion  5 , and its lower end portion is closed by a seal  4 . A check valve  51  is provided at the communicating portion  5 , and the cell  21  and the air passage  3  to be described later are communicated via this check valve  51 .  
         [0026]     Herein, without providing a check valve  51  for each cell  21  as in the present embodiment, for example, a check valve  51  may be provided in the vicinity of the enlarged portion  31  of the air passage  3 .  
         [0027]     In the present invention, a check valve  51  is not necessarily provided. For example, after being filled with air in the cells  21 , the communicating portion  5  may be closed by means of heat-sealing or the like. That is, it is sufficient to provide a closing means for closing the communicating portion  5  after filling air in the cell  21  so that the filled air does not escape outside the air-filling cushioning material. A concrete means is not limited thereto accordingly.  
         [0028]     Although not described in detail, the check valve  51  used in the present embodiment is made of a small piece of a soft resin sheet and has a flat and cylindrical shape where both ends are opened, thereby permitting an air-flow from one side end portion to the other, namely, an air-flow from the air passage  3  to the respective cells  21  in the present embodiment, and checking an air-flow in the reverse direction. Exemplified are a check valve disposed with a valve body seat capable of closing an air passage inside the check valve  51 , or a check valve formed with a partial seal so as to increase resistance against an air-flow in certain direction becomes large in comparison with one in the reverse direction. The mode for carrying out the check valve  51  is, however, not limited to these examples, and various check valves can be provided.  
         [0029]     Since the check valve  51  is provided for each cell  21  in the air-filling cushioning material  1  of the present embodiment 1, even if one of the cells  21  is damaged, deflation arises only on the damaged cell  21 . No influence is exerted on the other cells  21 , and a cushioning effect of the air-filling cushioning material  1  can be maintained.  
         [0030]     The air passage  3  in the present embodiment is a band-like passage positioned at an upper side of the cells  21  in the drawing and formed in the horizontal direction so as to be orthogonal to each of the respective cells  21 . This air passage  3  is opened at the right end side thereof in the drawing as an opening portion  3   a , and is closed at the left end side  3   b  thereof by a seal  4 . This opening portion  3   a  serves as an inlet to supply air in the internal space of the cells  21 .  
         [0031]     In other words, the cells  21  are formed so as to branch off from the air passage  3 , and air is filled in the cells  21  from the opening portion  3   a  of the air passage  3 . Air can thus be simultaneously filled in the plurality of cells  21  via the air passage  3 , achieving the efficient supply of air.  
         [0032]     The air passage  3  has a space thereinside where air can be circulated between the respective sheets  1   a ,  1   b  that are overlapped one sheet  1   a  and the other sheet  1   b  constituting an air-filling cushioning material  1 . In the present embodiment, the air passage  3  is composed of an enlarged portion  31  and a flat portion  32 , and the above-mentioned opening portion  3   a  corresponds to an end opening part of this enlarged portion  31 . The air passage  3  may be composed only of the enlarged portion  31  without the flat portion  32 .  
         [0033]     As shown in  FIG. 2 (D), the flat portion  32  is a portion simply formed by overlapping the flat sheets  1   a ,  1   b  like that of the conventional air-filling cushioning material.  
         [0034]     The enlarged portion  31  is a portion formed continuously to the flat portion  32 , and the internal space of the air passage  3  is formed at this enlarged portion  31  in an enlarged manner. That is, the air passage  3  has in this enlarged portion  31  the side length L2 (illustrated in  FIG. 2 (A)) of the enlarged portion  31  formed longer than the side length L1 (illustrated in  FIG. 2 (D)) of the flat portion  32  in terms of a cross sectional view. Since the side length is longer as such, the sheet  1   b  at the enlarged portion  31  is disposed in a slackening state in comparison with the flat portion  32 .  
         [0035]     Followings are examples of the shape of this enlarged portion  31 .  FIG. 2 (A) shows a shape formed in combination with a flat sheet  1   a  and the other sheet  1   b  deformed in a semicircular form.  FIG. 2 (B) shows a shape formed in combination with a flat sheet  1   a  and the other sheet  1   b  deformed by bending in an approximately V-shape so that the side length L2 of the other sheet  1   b  becomes longer compared to the side length L3, viewing a cross sectional shape of the air passage  3 .  FIG. 2 (C) shows a shape formed in combination with one sheet  1   a  and the other sheet  1   b  deformed in a semicircular shape respectively. The shape of the enlarged portion  30  is, however, not limited to these examples. As long as a deformed sheet is used for at least either one sheet  1   a  or the other sheet  1   b  in the enlarged portion  31  and the internal space of the enlarged portion  31  is formed in an enlarged manner, the present invention may be modified and carried out in various modes.  
         [0036]     With regard to a depth dimension W and a width dimension H of the enlarged portion  31  shown in  FIG. 1 , the dimensions can be set corresponding to an air-supplying nozzle. In the present embodiment, the enlarged portion  31  is formed with a depth dimension of approximately 50 mm and a width dimension of approximately 20 mm so as to suit for a nozzle with a diameter of approximately 8 mm to 10 mm.  
         [0037]     As a method for forming the enlarged portion  31  in the present embodiment, while inserting a pipe or a stick-like body between one sheet  1   a  and the other sheet  1   b  in a position where the enlarged portion  31  is to be formed, seals  4  to adhere both sheets  1   a ,  1   b  are provided, thus an enlarged internal space is formed. But it is not limited hereto, the present invention can be carried out by various methods, such as a method of closely fitting, by suction or the like, at least either sheet to a metal mold having a concavity in a position where the enlarged portion  31  is to be formed and overlapping, in this condition, one sheet  1   a  and the other sheet  1   b  and forming seals  4 .  
         [0038]     Filling air into the cells  21  of the air-filling cushioning material  1  wherein the enlarged portion  31  has been formed as such is carried out like the conventional art by inserting a nozzle or the like into the opening portion  3   a . Thereby, air supplied by a nozzle or the like passes through the air passage  3  and reaches the respective cells  21  via the check valves  51 . In the present embodiment, since the check valves  51  are provided for the respective cells  21 , the cells  21  can maintain an inflated condition after being filled with air.  
         [0039]     The planar air-filling cushioning material  1  formed as shown in  FIG. 1  can be utilized in various modes. Air can be filled into the cells  21  while maintaining this planar form. Also, an envelop-like or box-like three-dimensional shape may be utilized by folding up the air-filling cushioning material  1 . The present invention can be carried out in various modes as usage.  
         [0040]     In order for the cells to be inflatable or deflatable cell by cell, the check valve  51  may be attached so as to be operable to open from the outside of the air-filling cushioning material  1 , or an opening and closing means such as a fastener may be provided on the respective cells  21 , whereby some usage can be possible, such as inflating the cells  21  only at necessary portion, or deflating the air-filling cushioning material  1  by deaering the air-filled cells  21  after use and refilling air in using the same again.  
         [0041]     A slit may be formed beforehand on the air-filling cushioning material  1  so that the cells  21  can be torn from the slit in dumping. Or a cover, e.g. a detachable one, for a deaering opening portion may be provided on the cell  21  so as to deflate the cell  21  easily, reducing the same in volume.  
         [0042]     Application of the structure of the air passage  3  in the present invention is not limited to such an air-filling cushioning material  1  as in the present embodiment. This structure of the air passage  3  is applicable to any type of a bag  1  as long as a closed portion  2  has been formed therein, such as a deaering bag or a balloon or an air mattress. As for a deaerating bag, the air in the closed portion  2  having a space where air can be circulated, is discharged outside of the bag  1 .  
         [0043]     The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.