pressure vessel

Abstract

The objective is to provide a pressure-resistant container that can securely fasten the cap while suppressing spillage of the contents to the outside. [Solution] A pressure vessel 1 having a cylindrical mouth portion 10 with an internal thread 15 on its inner circumferential surface 10a, wherein an intermittent portion 20 is provided on the inner circumferential surface 10a of the mouth portion 10, in which the internal thread 15 is intermittently spaced at the same circumferential position, and the circumferential width of the intermittent portion 20 gradually narrows from top to bottom.

Description

Technical Field

[0001] The present invention relates to a pressure-resistant container having a cylindrical mouth portion with an internal thread on its inner peripheral surface.

Background Art

[0002] Conventionally, as a container used for applications such as containing a foaming liquid as a content liquid, such as soft drinks containing carbon dioxide gas such as carbonated water and soda, and alcoholic beverages such as beer and sparkling wine, a pressure-resistant container having a cylindrical mouth portion with an internal thread on its inner peripheral surface is known (see, for example, Patent Document 1).

[0003] In such a pressure-resistant container, the mouth portion is closed by the cap by screw-coupling a male thread provided on the outer peripheral surface of the cap's peripheral wall to a female thread provided on the inner peripheral surface of the mouth portion. Thus, even if the internal pressure of the container increases due to carbon dioxide gas, deformation of the cap's peripheral wall radially outward is restricted by the mouth portion, ensuring the sealing performance of the mouth portion by the cap.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the above conventional pressure-resistant container, when a configuration is adopted in which a plurality of turns of internal threads are provided on the inner peripheral surface of the mouth portion, after the container is tilted and the content liquid is poured out from the mouth portion, when the container is returned to a upright position, the flow of the content liquid back into the container is obstructed by the internal threads, and there is a problem that the content liquid remaining on the internal threads may leak out.

[0006] On the other hand, there are known pressure vessels with multiple female threads on the inner surface of the opening, which have intermittent sections (vent slots) where the female threads are spaced apart on the inner surface of the opening. When the cap is opened, the pressure of the carbon dioxide gas inside the container is released to the outside through these intermittent sections, preventing the cap from being blown off. In such pressure vessels, the intermittent sections function as flow channels that direct the liquid contents remaining in the female threads towards the inside of the container.

[0007] However, in conventional pressure vessels, the intermittent section is formed by making multiple turns of female threads straight and intermittent from top to bottom with the same width. If the width of the intermittent section is made wide enough so that the flow of the liquid contents into the container is not obstructed by the female threads, the engagement force of the female threads on the male threads of the cap becomes small, and the cap cannot be fixed to the opening with sufficient strength.

[0008] The present invention aims to solve these problems, and its objective is to provide a pressure-resistant container that can securely fasten a cap while suppressing spillage of the contents to the outside. [Means for solving the problem]

[0009] The pressure vessel of the present invention is a pressure vessel having a cylindrical mouth portion with an internal thread on its inner circumferential surface, wherein the inner circumferential surface of the mouth portion is provided with an intermittent portion in which the internal thread is intermittently spaced at the same circumferential position, and the circumferential width of the intermittent portion gradually narrows from top to bottom.

[0010] In the pressure-resistant bottle container of the present invention, it is preferable that a plurality of the aforementioned intermittent portions are provided on the inner circumferential surface of the mouth portion at intervals in the circumferential direction.

[0011] In the pressure vessel of the present invention, it is preferable that a cylindrical portion without female threads is provided above the portion of the mouth where the female threads are formed.

[0012] In the pressure vessel of the present invention, it is preferable that a cylindrical enlarged diameter portion having a larger diameter than the opening is integrally provided at the upper end of the opening, and the non-threaded portion is provided in the enlarged diameter portion.

[0013] In the pressure vessel of the present invention, it is preferable that a projection is provided on the outer circumferential surface of the lower end portion of the enlarged diameter section, projecting radially outward. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a pressure-resistant container that can securely fasten the cap while suppressing spillage of the contents to the outside. [Brief explanation of the drawing]

[0015] [Figure 1] This is a front view with a portion of a pressure vessel according to one embodiment of the present invention cut out. [Figure 2] Figure 1 is a plan view of the pressure vessel. [Figure 3] This is a cross-sectional view along line AA in Figure 2. [Figure 4] This is a cross-sectional view along line BB in Figure 2. [Modes for carrying out the invention]

[0016] A pressure vessel according to one embodiment of the present invention will be described in more detail below with reference to the drawings.

[0017] The pressure vessel 1 according to one embodiment of the present invention shown in Figures 1 and 2 is used to contain beverages containing carbon dioxide as its contents, such as carbonated water, soft drinks such as soda, and alcoholic beverages such as beer and sparkling wine. For example, the pressure vessel 1 is used to contain a contents containing 2 GV or more of carbon dioxide. "GV" is a unit that represents the amount of carbon dioxide dissolved in a liquid, and under standard conditions, 1 GV (gas volume) is defined as 1 L of carbon dioxide dissolved in 1 L of liquid.

[0018] In addition, if the pressure-resistant container 1 contains a liquid with foaming properties, it may be used for the purpose of containing a liquid other than a beverage containing carbon dioxide gas as the content liquid. Further, the pressure-resistant container 1 may be used for the purpose of containing a non-foaming content liquid.

[0019] In this embodiment, the pressure-resistant container 1 is a blow-molded container made of synthetic resin formed by blow-molding a preform formed by injection-molding a synthetic resin material such as polyethylene terephthalate resin.

[0020] Note that the pressure-resistant container 1 may be made of a synthetic resin other than polyethylene terephthalate resin, or may be formed of a material other than synthetic resin such as glass. Further, the pressure-resistant container 1 may be formed by a manufacturing method other than blow molding, for example.

[0021] The pressure-resistant container 1 has a bottle shape having a cylindrical mouth portion 10 centered on an axis O, a cylindrical body portion 11 coaxial with the mouth portion 10 that is integrally connected to the lower end of the mouth portion 10, and a petaloid-shaped bottom portion 12 that closes the lower end of the body portion 11. The outer diameter of the body portion 11 is larger than the outer diameter of the mouth portion 10, and the body portion 11 is connected to the mouth portion 10 via a shoulder portion 13. Further, a neck ring 14 may be integrally provided on the outer peripheral surface of the mouth portion 10.

[0022] Note that the shape of the pressure-resistant container 1 may be other than the bottle shape as long as it has a cylindrical mouth portion 10.

[0023] The inner diameter of the mouth portion 10 is preferably at least 1 / 2 of the outer diameter of the body portion 11. Thereby, the pressure-resistant container 1 becomes a so-called wide-mouth container, and the ease of drinking when directly attaching the mouth to the mouth portion 10 to drink the content liquid can be improved. Note that the inner diameter of the mouth portion 10 is preferably 30 mm to 45 mm, more preferably 37 mm to 45 mm, but is not limited to these numerical ranges.

[0024] The inside of the body portion 11 is a storage space (not shown) connected to the opening portion 10, and the pressure vessel 1 can store liquid contents inside the storage space through the opening portion 10, and can also pour the liquid contents stored in the storage space to the outside through the opening portion 10.

[0025] Herein, in the claims and this specification, the vertical direction means the vertical direction when the pressure vessel 1 is in an upright position as shown in Figure 1, the circumferential direction means the direction of rotation around the axis O, and the radial direction means the direction perpendicular to the axis O.

[0026] As shown in Figure 3, a female thread 15 is formed on the inner circumferential surface 10a of the mouth portion 10. In this embodiment, a female thread 15 with multiple turns is formed on the inner circumferential surface 10a of the mouth portion 10. Here, "multiple turns" means that the female thread 15 is provided on the inner circumferential surface 10a of the mouth portion 10, extending spirally around the axis O over a range of 360 degrees or more in the circumferential direction, and that multiple threads 15a constituting the female thread 15 are arranged in multiple rows in the vertical direction at any circumferential position on the inner circumferential surface 10a of the mouth portion 10. In this embodiment, the female thread 15 with multiple turns is composed of a single thread, and is configured such that at least three threads 15a are arranged in the vertical direction at any circumferential position on the inner circumferential surface 10a of the mouth portion 10.

[0027] Furthermore, the female thread 15 is not limited to being composed of a single thread, but may also be a multi-start thread with multiple threads 15a. In this case, if the threads 15a of different threads are arranged in multiple rows in the vertical direction, each thread 15a may have only one turn.

[0028] The opening 10b at the top of the mouth portion 10 is closed by attaching a cap (not shown). The cap is made of synthetic resin, for example, and has male threads on the outer surface of its peripheral wall. The male threads are screw-connected to female threads 15 formed on the inner surface 10a of the mouth portion 10, so that the cap can be attached to the mouth portion 10 in a detachable manner.

[0029] In this embodiment, the female thread 15 is formed by a plurality of core molds arranged circumferentially when injection molding a preform for forming the pressure vessel 1 by blow molding. The plurality of core molds are configured to move radially inward after forming the female thread 15, thereby detaching from the female thread 15 and being removed from the inside of the opening 10. As a result, a parting line extending vertically is formed on the inner circumferential surface 10a of the opening 10 after molding. Therefore, when a cap is attached to the opening 10, the sealing performance is hindered by the parting line, making it difficult to ensure a proper seal on the inner circumferential surface 10a with the cap.

[0030] In contrast, in this embodiment, a cylindrical enlarged diameter portion 16, which is larger in diameter and coaxial with the mouth portion 10, is integrally attached to the upper end of the mouth portion 10. The inner circumferential surface of the enlarged diameter portion 16 is larger in diameter than the inner circumferential surface 10a of the mouth portion 10. Furthermore, the inner circumferential surface of the enlarged diameter portion 16 is a non-threaded portion 16a where the female thread 15 is not formed. When a cap (not shown) is attached to the mouth portion 10, the sealing cylinder portion provided on the cap fits liquid-tightly around the non-threaded portion 16a over its entire circumference. This eliminates the obstruction of sealing performance by the parting line and improves the sealing performance of the mouth portion 10 by the cap.

[0031] When an enlarged diameter portion 16 is provided at the upper end of the opening portion 10, it is preferable to replace the opening portion 10 with an inner diameter of 30 mm to 45 mm, and more preferably 37 mm to 45 mm, but it is not limited to these numerical ranges. Alternatively, instead of providing an enlarged diameter portion 16 at the upper end of the opening portion 10, a non-threaded portion where the female thread 15 is not formed may be provided above the portion where the female thread 15 is formed on the inner circumferential surface 10a of the opening portion 10. The vertical range of the non-threaded portion is preferably 40 to 80% of the vertical range where the female thread 15 is formed on the inner circumferential surface 10a of the opening portion 10.

[0032] If an enlarged diameter portion 16 is provided at the upper end of the opening portion 10, a projection 16b projecting radially outward may be provided on the outer circumferential surface of the lower end portion of the enlarged diameter portion 16. In this embodiment, the projection 16b is an annular shape extending around the entire circumference of the outer circumferential surface of the enlarged diameter portion 16. The projection 16b can be used, for example, to engage with a virgin ring provided at the lower end of the peripheral wall of the cap.

[0033] The inner circumferential surface 10a of the opening 10 is provided with intermittent sections 20 in which multiple turns of female thread 15 are intermittently spaced at the same circumferential position. As shown in Figure 2, in this embodiment, the inner circumferential surface 10a of the opening 10 is provided with four intermittent sections 20 arranged at equal intervals in the circumferential direction. The four intermittent sections 20 differ only in their circumferential positions; their basic shape and configuration are identical to each other.

[0034] In this embodiment, four intermittent sections 20 are provided on the inner circumferential surface 10a of the opening 10, arranged at equal intervals in the circumferential direction. However, as long as at least one intermittent section 20 is provided, the number and arrangement can be changed as appropriate.

[0035] As shown in Figure 4, the intermittent portion 20 is provided extending vertically between the upper end position 21 and the lower end position 22 of the female thread 15 on the inner circumferential surface 10a of the opening 10, by cutting out three threads 15a arranged vertically in the female thread 15 of the multi-turn female thread 15 at the same circumferential position. More specifically, the intermittent portion 20 is the portion where the female thread 15 is not provided, enclosed by the upper end position 21, the lower end position 22, a virtual line 23 connecting the tip portions on one side of the cut-out circumferential direction of each thread 15a, and a virtual line 24 connecting the tip portions on the other side of the cut-out circumferential direction of each thread 15a. In this embodiment, the tip portions that demarcate the intermittent portion 20 of each thread 15a have a linear shape along the virtual line 23 or virtual line 24, and the thread height gradually increases from the tip portion toward the opposite side of the intermittent portion 20.

[0036] Here, the intermittent section 20 has a shape in which the circumferential width gradually narrows from top to bottom. That is, the circumferential width D1 at the upper end position 21 of the intermittent section 20 is wider than the circumferential width D2 at the lower end position 22 of the intermittent section 20.

[0037] In this embodiment, the intermittent portion 20 has a tapered shape in which the width in the circumferential direction gradually narrows from top to bottom. This is achieved by cutting out three threads 15a of the female screw 15 such that, with respect to a virtual line 25 extending vertically on the inner circumferential surface 10a of the opening portion 10, one virtual line 23 in the circumferential direction is inclined so that it moves further away from the virtual line 25 as it goes higher, and the other virtual line 24 in the circumferential direction is inclined so that it moves further away from the virtual line 25 as it goes higher, resulting in a tapered shape in which the width in the circumferential direction gradually narrows from top to bottom. In this embodiment, the width in the circumferential direction D1 at the upper end position 21 of the intermittent portion 20 is 10 mm, and the width in the circumferential direction D2 at the lower end position 22 is 8 mm.

[0038] Furthermore, the intermittent portion 20 is not limited to the tapered shape described above. It can take any shape as long as multiple rows of threads 15a arranged vertically in the female thread 15 with multiple turns are cut out at the same circumferential position, and the circumferential width gradually narrows from top to bottom. For example, it could be a shape where either imaginary line 23 or imaginary line 24 is parallel to imaginary line 25, or a shape where imaginary lines 23 and 24 are curved. In addition, the circumferential width D1 at the upper end position 21 and the circumferential width D2 at the lower end position 22 of the intermittent portion 20 are not limited to the 10 mm and 8 mm described above, but can be changed as appropriate.

[0039] In this embodiment, the inner diameter of the portion of the inner circumferential surface 10a of the mouth portion 10 in which the intermittent portion 20 is provided is the same as the inner diameter of the other portion in which the intermittent portion 20 is not provided. However, the inner diameter of the portion in which the intermittent portion 20 is provided may be larger than the inner diameter of the other portion in which the intermittent portion 20 is not provided. That is, the intermittent portion 20 may be a groove-like shape that is recessed radially outward relative to the other portion of the inner circumferential surface 10a of the mouth portion 10. In this case, the recessed groove-like portion may extend beyond the range of the intermittent portion 20, from the opening 10b at the upper end of the mouth portion 10 to the lower end of the mouth portion 10.

[0040] As described above, in the pressure vessel 1 according to this embodiment, an intermittent section 20 is provided on the inner circumferential surface 10a of the mouth 10, in which multiple turns of female thread 15 are intermittently spaced at the same circumferential position. This allows the contents to flow vertically along the intermittent section 20 between the internal storage space of the pressure vessel 1 and the opening 10b at the upper end of the mouth 10 without being obstructed by the female thread 15. As a result, when the pressure vessel 1 is tilted and the contents are poured out from the opening 10a of the mouth 10, the contents contained in the storage space of the pressure vessel 1 can be effectively poured out from the opening 10b along the inner circumferential surface 10a through the intermittent section 20. Furthermore, when the pressure vessel 1 is returned to an upright position after the contents have been poured out from the mouth 10, the contents can be effectively poured back into the storage space of the pressure vessel 1 through the intermittent section 20 without being obstructed by the female thread 15, thereby preventing the contents from remaining on the female thread 15 and spilling out.

[0041] Furthermore, in the pressure vessel 1 according to this embodiment, the intermittent section 20 has a shape in which its circumferential width gradually narrows from top to bottom. This ensures that the intermittent section 20 has sufficient width so that the flow of the liquid contents is not obstructed by the female thread 15, while the female thread 15, particularly the lower thread 15a, has a length sufficient to engage with the male thread of the cap, thereby ensuring the engagement force of the female thread 15 with the cap. As a result, the cap can be fixed to the opening 10 with sufficient strength.

[0042] Furthermore, in this embodiment, since multiple intermittent portions 20 are provided on the inner circumferential surface 10a of the mouth portion 10 at intervals in the circumferential direction, regardless of the direction in which the pressure vessel 1 is tilted, the liquid contents contained in the storage space of the pressure vessel 1 can be effectively poured out from the opening 10b along the inner circumferential surface 10a through the intermittent portions 20. In addition, when the pressure vessel 1 is returned to an upright position after the liquid contents have been poured out from the mouth portion 10, the liquid contents can be effectively flowed back into the storage space of the pressure vessel 1 through the intermittent portions 20, thereby suppressing spillage of the liquid contents to the outside.

[0043] Furthermore, in this embodiment, a cylindrical enlarged diameter portion 16, which has a larger diameter than the mouth portion 10, is integrally attached to the upper end of the mouth portion 10, i.e., the opening 10b. This allows the user to directly place their mouth on the enlarged diameter portion 16 and drink the contents, resulting in a pleasant mouthfeel.

[0044] The present invention is not limited to the embodiments described above, and it goes without saying that various modifications are possible without departing from the spirit of the invention.

[0045] For example, the female thread 15 may have only one turn, not necessarily multiple turns, as long as the engagement of the cap is not impaired by internal pressure. [Explanation of symbols]

[0046] 1. Pressure vessel 10 Mouth 10a Inner surface 10b opening 11 Torso 12 Bottom 13 Shoulder-shaped part 14 Neck Rings 15 Female thread 15a thread 16 Expanded diameter part 16a Non-threaded portion 16b Protrusion 20 Intermittent section 21 Top position 22 Bottom position 23 virtual lines 24 virtual lines 25 virtual lines O axis D1 width D2 width

Claims

1. A pressure vessel having a cylindrical opening with an internal thread on its inner surface, The inner circumferential surface of the opening is provided with intermittent portions in which the female threads are intermittently spaced at the same circumferential position. A pressure vessel characterized in that the circumferential width of the intermittent portion gradually narrows from top to bottom.

2. The pressure vessel according to claim 1, wherein a plurality of the intermittent portions are provided on the inner circumferential surface of the opening at intervals in the circumferential direction.

3. The pressure vessel according to claim 1 or 2, wherein a cylindrical portion without the female thread is provided above the portion of the mouth where the female thread is formed.

4. A cylindrical enlarged diameter portion, having a larger diameter than the aforementioned opening, is integrally attached to the upper end of the aforementioned opening. The pressure vessel according to claim 3, wherein the enlarged diameter portion is provided with the portion that does not form a female thread.

5. The pressure vessel according to claim 4, wherein a projection is provided on the outer circumferential surface of the lower end portion of the enlarged diameter section, projecting radially outward.

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