The present invention relates to an air bag to be mounted in a cargo container for facilitating the discharge of powder granular material (i.e., powder and/or granular material) from a liner filled with the powder granular material.
Patent Documents 1 and 2 below disclose an air bag to be mounted in a cargo container for facilitating the discharge of powder granular material from a liner filled with the powder granular material. This airbag includes a synthetic resin film bag that assumes a triangle or trapezoid shape in a state where the bag has a flat form with no air injected. For example, the air bag is arranged at a predetermined position in a liner that includes an outlet on its one end wall, i.e., in such a manner that the base of the triangle or the lower base of the trapezoid is adjusted to the one end wall of the liner so that the air bag extends along the inner surface of one side wall and the top surface of a bottom wall of the liner. Alternatively, the air bag is arranged at a predetermined position between the liner and a cargo container mounted with the liner, i.e., in such a manner that the base of the triangle or the lower base of the trapezoid is adjusted to the one end wall of the liner so that the air bag extends along the outer surface of the one side wall and the under surface of the bottom wall of the liner. The cargo container is inclined so that the one end wall of the liner is directed downward, and the outlet is opened to discharge approximately the whole powder granular material from the liner. Thereafter, the air bag is inflated with injected air, thereby forcing powder granular material remaining in one lower part of the one end wall of the liner toward the outlet to facilitate the discharge of the residue.
The conventional air bag as described above has the following problems: (1) When the bag is inflated, the base of the triangle or the lower base of the trapezoid is deformed into a convex arc shape toward the vertex of the triangle or the upper base of the trapezoid to form a so-called pocket space, which impedes powder granular material remaining in the one lower part of the one end wall of the liner from being forced toward the outlet in a sufficiently effective manner, resulting in a substantial amount of powder granular material remaining in the pocket space (Patent Document 1 discloses providing the air bag with an extension part to suppress the pocket space creation, which, however, leads to another problem that the extension part interferes with one or more of a plurality of the outlets formed in the liner); (2) When the bag is inflated, the bag, especially its heat-sealed portions (both side portions of the triangle or both leg portions of the trapezoid), may be broken; and (3) The air bag is non-reusable and is thrown away after a single use.
The present invention has been made in view of the aforementioned facts, and a main technical object thereof is to provide a novel and improved air bag that brings a solution to at least one of the above-described problems of the conventional air bag.
As a solution to the above-described problem (1) of the conventional air bag, a first aspect of the present invention provides an air bag to be mounted in a cargo container for facilitating discharge of powder granular material from a liner filled with the powder granular material. The air bag includes a synthetic resin film bag that assumes a triangle or trapezoid shape in a state where the bag has a flat form with no air injected. A gusset is formed in a base part of the triangle or a lower base part of the trapezoid by folding the synthetic resin film inward.
As a solution to the above-described problem (2) of the conventional air bag, a second aspect of the present invention provides an air bag to be mounted in a cargo container for facilitating discharge of powder granular material from a liner filled with the powder granular material. The air bag includes a synthetic resin film bag that assumes a triangle or trapezoid shape in a state where the bag has a flat form with no air injected. Flexible reinforcing covers having a triangle or trapezoid shape in accordance with the shape of the bag are laminated respectively on one surface and the other surface of the bag.
As a solution to the above-described problem (3) of the conventional air bag, a third aspect of the present invention provides an air bag to be mounted in a cargo container for facilitating discharge of powder granular material from a liner filled with the powder granular material. The air bag includes a synthetic resin film bag that assumes a triangle or trapezoid shape in a state where the bag has a flat form with no air injected. A short air outlet tube, as well as an air inlet tube, is connected to one side part of the triangle or one leg part of the trapezoid of the bag.
It is desirable that the one surface and the other surface of the bag are welded to each other along both sides of the triangle or both legs of the trapezoid, and the reinforcing covers are bonded respectively to the one surface and the other surface of the bag along the both sides of the triangle or the both legs of the trapezoid of the bag. It is preferable that the air inlet tube and the air outlet tube are made of a synthetic resin film. It is suitable that the air bag is arranged between an inner surface of a side wall as well as a top surface of a bottom wall of the container and an outer surface of a side wall as well as an outer surface of a bottom wall of the liner that respectively face the inner surface of the side wall as well as the top surface of the bottom wall of the container, in such a manner that the base of the triangle or the lower base of the trapezoid of the bag is adjusted to one end wall of the liner on which an outlet is formed.
In the air bag according to the first aspect of the present invention, the gusset is formed in the base part of the triangle or the lower base part of the trapezoid by folding the synthetic resin film inward from both one surface side and the other surface side. Thus, an approximately flat bottom is formed at the base of the triangle or the lower base of the trapezoid when the bag is inflated. As a result, the bag is prevented from being deformed into a convex arc shape toward the vertex of the triangle or the upper base of the trapezoid to form a so-called pocket space. Therefore, powder granular material remaining in one lower part of the one end wall of the liner can be forced toward the outlet in a sufficiently effective manner.
In the air bag according to the second aspect of the present invention, the flexible reinforcing covers having a triangle or trapezoid shape in accordance with the triangle or trapezoid shape of the bag are laminated respectively on the one surface and the other surface of the bag. Thus, the bag, especially its heat-sealed portions (both the side portions of the triangle or both the leg portions of the trapezoid), is prevented as much as possible from being broken when the bag is inflated.
In the airbag according to the third aspect of the present invention, the air outlet tube, in addition to the air inlet tube, is connected to the one side part of the triangle or the one leg part of the trapezoid of the bag. Thus, injected air in the bag can be sufficiently easily exhausted through the short air outlet tube, which allows for reuse of the air bag.
Hereinafter, a preferred embodiment of an air bag constructed in accordance with the present invention will be described in more detail with reference to the attached drawings.
The liner 2, the cargo container, and the bulkhead as described above themselves are well-known and do not constitute a part of the air bag constructed in accordance with the present invention; thus a detailed description thereof will be omitted in the specification.
An air inlet tube 50 and an air outlet tube 52 are connected to the leg 38a of the trapezoid bag 32. It is important that the air inlet tube 50 is relatively long, while the air outlet tube 52 is relatively short (the reason will be described later.) Each of the air inlet tube 50 and the air outlet tube 52, which needs to communicate with the inside of the bag 32, can be connected to the bag 32 in the following manner: A tube formed from an appropriate synthetic resin film such as a polyethylene film is cut to a required length; one end of the cut tube is located between both the surfaces of the tube 42 prior to welding along the welding line 46a; and both the surfaces of the tube 42 are welded together along the welding line 46a. In order to prevent the air inlet tube 50 and the air outlet tube 52 themselves from being welded and closed during the welding of both the surfaces of the tube 42, a non-welding sheet material piece (not shown) such as a paper sheet piece can be inserted into the one end of each of the air inlet tube 50 and the air outlet tube 52.
The description will continue with reference to
As shown in
Next, a description will be given of a typical way of using the air bag 30 as described above. According to the embodiment shown in
When powder granular material is to be discharged from the liner 2, the cargo container is tilted, so that the liner 2 is inclined in such a manner that the one end wall 4 is directed downward while the other end wall 6 is directed upward. Prior to the tilting of the cargo container, one of the paired doors, i.e., the door on the user's right, of the cargo container is opened, so that the outlet 18b of the liner 2 is exposed. Thereafter, the binding cord tied to the tube forming the outlet 18b is untied to open the outlet 18b, to which an appropriate outlet guide pipe (not shown) is connected. Then, powder granular material is discharged from the liner 2 through the outlet 18b and the outlet guide pipe. Even after most powder granular material in the liner 2 has been discharged, a substantial amount of powder granular material still remains in the lower corner between the one end wall 4 and the side wall 12 of the liner, due to the fact that powder granular material is discharged through the outlet 18b located in the lower right part of the one end wall 4 of the liner 2. In order to facilitate the discharge of such residual powder granular material, the relatively long air inlet tube 50 attached to the air bag 30 is pulled out from the cargo container, and air is injected into the bag 32 through the air inlet tube 50. As a result, the bag 32 is inflated as shown in
The bag 32 of the air bag 30 constructed in accordance with the present invention includes the gusset 40 in its lower base part. Thus, as clearly shown in
Further, according to the air bag 30 constructed in accordance with the present invention, the reinforcing covers 54a and 54b are laminated on both the surfaces of the air bag 32. Thus, for example, the air bag 32 is prevented as much as possible from being broken in the vicinity of the legs 38a and 38b of the air bag 32 when air is injected into the air bag 32.
After powder granular material in the liner 2 has been sufficiently discharged due to the action of the air bag 30, the liner 2 is usually removed from the cargo container and discarded. Afterwards, the cargo container becomes available to a field user, who then enters the cargo container, inserts an aspiration nozzle (not shown) of an air suction machine brought in from outside the cargo container into the air bag 32 through the air outlet tube 52 of the air bag 30, and gets the air suction machine working to exhaust air from the air bag 32 (if the aspiration nozzle of the air suction machine is merely connected to the outer end of the air outlet tube 52 to exhaust air in the air bag 32, the air outlet tube 52 is closed during air aspiration, making it impossible to exhaust air.) According to the air bag 30 constructed in accordance with the present invention, the air inlet tube 50, which is used in a state where the liner 2 is mounted in the cargo container, is relatively long because it needs to be pulled out from the cargo container. On the other hand, the air outlet tube 52, which becomes available to a field user who enters the cargo container after the removal of the liner 2 from the cargo container, is relatively short. Thus, it is sufficiently easy to insert the aspiration nozzle of the air suction machine into the air bag 32 through the air outlet tube 52. After air has been exhausted from the bag 32, the airbag 30 can be used repeatedly for another liner to be mounted in a cargo container and filled with powder granular material.
In a case where the two doors of the cargo container are opened, so that powder granular material in the liner 2 is discharged not only through the outlet 18b but also through the outlet 18a, only a slight amount of powder granular material remains in the liner 2, and accordingly the air bag 30 is not necessarily required to be activated. Meanwhile, in a case where the liner has only one outlet at the center of the one end wall in the width direction, powder granular material tends to remain in both side parts of the liner. In such a case, two air bags 30 can be attached, one to one side of the liner and the other to the other side of the liner.
Number | Date | Country | Kind |
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2019-223416 | Dec 2019 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2020/041579 | 11/6/2020 | WO |