CN113412224B

CN113412224B - Cover

Info

Publication number: CN113412224B
Application number: CN202080013498.9A
Authority: CN
Inventors: 黑岩靖文; 川村伸生; 小野淳史; 梅木慎吾
Original assignee: Nihon Yamamura Glass Co Ltd
Current assignee: Nihon Yamamura Glass Co Ltd
Priority date: 2019-03-07
Filing date: 2020-02-27
Publication date: 2023-01-13
Anticipated expiration: 2040-02-27
Also published as: CN113412224A; JP2020142836A; JP6655741B1; WO2020179608A1; KR20210126105A

Abstract

The invention provides a cover capable of preventing blow-off and overrun. A cap (1) which is attached to a container mouth so as to cover the container mouth, and which is provided with a top wall (2) and a substantially cylindrical skirt wall (3) extending downward from the outer periphery of the top wall (2), wherein an internal thread (5) to be screwed with an external thread formed on the outer periphery of the container mouth is provided on the skirt wall (3), and the wall thickness of a lower portion (14) located below the internal thread (5) is made larger than the wall thickness of an upper portion (15) located above the internal thread (5) on the skirt wall (3).

Description

Cover

Technical Field

The present invention relates to a cap to be attached to a mouth of a container for storing contents such as drinks.

Background

As shown in fig. 3 (a) and (B), a cap 51 is widely used for various containers for beverages and the like, and the cap 51 is detachably attached to a mouth portion M of the container by screwing, and serves to close and open the mouth portion M of the container (patent document 1).

Documents of the prior art

Patent literature

Patent document 1: japanese patent No. 5291175

Disclosure of Invention

Problems to be solved by the invention

However, in the above-described conventional cap 51 attached to the container mouth portion M by screwing, the engagement range (area) of the female screw 52 of the cap 51 with the male screw M1 of the container mouth portion M becomes narrow with the opening operation, but the cap 51 does not fall off from the container mouth portion M as long as the male screw M1 is engaged with the female screw 52. However, for example, when a carbonated beverage is filled in the container, if the lid 51 is pushed up in a state where the male screw M1 is engaged with the female screw 52 due to an increase in the internal pressure of the container by the gas pressure from the carbon dioxide gas, and the engagement is released by an increase in the diameter of the skirt wall 53 of the lid 51 to such an extent that the skirt wall can get over the male screw M1, a phenomenon called blow-off occurs in which the lid bursts.

In the conventional cap described above, if the cap is screwed too tightly when the cap is attached to the container mouth, overrun (overrun) occurs (the female screw of the cap gets over the male screw of the container mouth), and the cap may not be closed sufficiently.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a cover capable of achieving blow-off prevention and overrun.

Means for solving the problems

In order to achieve the above object, a cap according to the present invention is attached to a container mouth portion so as to cover the container mouth portion, and includes: a top wall; and a substantially cylindrical skirt wall extending downward from an outer peripheral portion of the top wall, wherein the skirt wall is provided with a female screw to be screwed with a male screw formed on an outer periphery of the container mouth, and a thickness of a lower portion of the skirt wall positioned below the female screw is made larger than a thickness of an upper portion of the skirt wall positioned above the female screw (claim 1).

In the lid, the thickness of the portion of the skirt wall other than the female screw may be increased downward in the region from the upper portion to the lower portion (claim 2).

Effects of the invention

According to the invention, the cover capable of preventing blow-off and overrun can be obtained.

That is, in the cap of the present invention, since the thickness of the lower portion is made larger than the thickness of the upper portion, the skirt wall is less likely to be deformed in an enlarged diameter as compared with the case where the thickness of the lower portion is equal to or smaller than the thickness of the upper portion. Therefore, for example, in the case where a carbonated beverage is filled in the container, even if the internal pressure of the container rises due to the gas pressure from the carbon dioxide gas and a force pushing up the lid is applied in a state where the male screw of the container mouth portion is engaged with the female screw of the lid, the skirt wall is less likely to expand in diameter as described above, and therefore, it is possible to prevent the engagement from being released by the expansion of the diameter of the skirt wall to such an extent that the diameter can get over the male screw, and it is possible to prevent the occurrence of blowing.

In addition, since the skirt wall is difficult to expand in diameter, it is also possible to prevent the occurrence of overrun (the internal thread of the cap overrides the external thread of the container mouth).

On the other hand, if the thickness of the portion of the skirt wall excluding the female thread in the female thread forming region in which the female thread is formed is equal to or less than the thickness of the upper portion, there is a possibility that the diameter of the female thread forming region is enlarged, and the prevention of the blow-off and the overrun cannot be sufficiently achieved.

Drawings

Fig. 1 (base:Sub>A) isbase:Sub>A bottom view schematically showing the structure ofbase:Sub>A cap according to an embodiment of the present invention, and (B) isbase:Sub>A cross-sectional view taken along linebase:Sub>A-base:Sub>A of (base:Sub>A).

FIG. 2 is a sectional view taken along line B-B in FIG. 1 (A).

Fig. 3 (a) is a front view showing a conventional synthetic resin cap, and (B) is a front view showing a state of being attached to a mouth portion of the container.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings.

A synthetic resin cap (hereinafter referred to as a cap) 1 shown in fig. 1 a and B is used by being attached to and covering a container mouth M (for example, a mouth of a container such as a PET bottle) having a male screw M1 and an annular protrusion (an example of an engaged portion) M2 shown in fig. 3B, and is integrally molded from polyethylene by compression molding or injection molding. The material for forming the cap 1 is not particularly limited, and polypropylene or the like is suitably used in addition to polyethylene used in the present embodiment.

The cap 1 has a top wall 2 having a substantially circular shape in plan view, and a substantially cylindrical skirt wall 3 extending downward from an outer peripheral portion of the top wall 2 (see fig. 1 (a) and (B)). As shown in fig. 1 (B), a knurled groove 4 is provided on the outer peripheral surface of the skirt wall 3, and a female screw 5 is provided on the inner peripheral surface, and the female screw 5 can be coupled to a male screw M1 formed on the outer periphery of the container mouth M.

When the cap 1 is rotated so that the female screw 5 of the skirt wall 3 is coupled to the male screw M1 of the container mouth M and attached to the container mouth M, an annular center leg (inner ring) 6, an annular rib 7, and an annular outer leg (outer ring) 8, which are continuously provided on the inner surface (lower surface) of the top wall 2 shown in fig. 1B, are brought into close contact with the container mouth M, whereby the container mouth M is sealed. That is, in the state where the cap 1 is attached to the container mouth M, the center leg 6 is inserted into the container mouth M and is in close contact with the inner peripheral surface of the container mouth M, the annular rib 7 is in close contact with the annular upper end surface of the container mouth M, and the outer leg 8 is in close contact with the outer peripheral surface of the container mouth M.

The cap 1 is a tamper-proof cap having a function of proving that it is not opened (not opened at a time), and is configured such that: when the unopened cap 1 attached to the container mouth portion M is unsealed (first opened), the cap 1 is rotated to release the engagement between the male screw M1 and the female screw 5, and the cap 1 is detached from the container mouth portion M, but a tamper evident band (hereinafter, simply referred to as "band") 9 (see fig. 1B) connected to the lower portion of the skirt wall 3 remains in the container mouth portion M.

That is, the band 9 is connected to the lower portion of the skirt wall 3 by the annular weakened portion 10 extending along the entire circumference of the skirt wall 3 (see fig. 1B), and the annular weakened portion 10 is constituted by slits (slit-like slits) intermittently extending in the circumferential direction of the skirt wall 3 and the band 9 so as to divide the skirt wall 3 and the band 9 vertically and bridges (bridge portions) present between the adjacent slits, and the bridges are broken when they are stretched with a predetermined force.

Here, in this example, the outer diameter of the belt 9 is made uniform in the upper and lower portions, and on the other hand, 5 (one example of 2 or more) hooks (one example of engaging portions) 11 are provided on the inner peripheral side of the belt 9 at intervals in the circumferential direction (at equal intervals in this example), and the hooks protrude inward so that the amount of protrusion inward increases toward the upper side (see fig. 1 (a) and (B)). In a state where the cap 1 is attached to the container mouth portion M, each hook 11 is positioned slightly below an annular projection M2 (see fig. 3B) formed on the outer periphery of the container mouth portion M below the male screw M1, and is locked to the annular projection M2 by the unsealing operation. That is, the hook 11 is configured to be engageable with the annular projection M2 from below. The two-dot chain line in the lower part of fig. 2 shows the cross-sectional shape of the portion where the hook 11 is not provided.

As shown in fig. 1B and 2, a fitting portion 12 that projects inward of the inner surface of the upper end portion of the strap 9 and has a maximum projection amount smaller than the maximum projection amount of the hook 11 (an inner diameter larger than the inner diameter of the hook 11) is provided on the inner circumferential side of the strap 9 along the entire circumference of the strap 9 above the hook 11, and a slope portion 13 having an inner diameter that increases toward the upper side is connected above the fitting portion 12.

Accordingly, when the cap 1 is rotated in the unsealing direction from the state in which the cap 1 is attached to the container mouth portion M and is not unsealed, the cap 1 is relatively raised with respect to the container mouth portion M, the fitting portion 12 is fitted to the annular projection M2, and the hook 11 is engaged with the annular projection M2 from below. Further, when the cap 1 is further rotated in the unsealing direction, the annular weakened portion 10 is finally broken, and the band 9 remains in the container mouth portion M, while the cap body composed of the top wall 2 and the skirt wall 3 on the upper side than the band is detached from the container mouth portion M.

Therefore, until the hook 11 is engaged with the annular projection M2 from below, the inclined portion 13 abuts against the annular projection M2, and the fitting portion 12 is fitted to the outer peripheral surface of the annular projection M2, so that the band 9 is prevented from being obliquely lifted up, and the annular weakened portion 10 is broken substantially uniformly without being biased, and thus the theft performance is good. Further, at the time of opening, the fitting portion 12 is fitted to the outer peripheral surface of the annular projection M2 of the container mouth portion M, and the hook 11 is reliably engaged with the annular projection M2, so that the occurrence of so-called falling-off in which the hook 11 passes over the annular projection M2 without breaking the annular weakened portion 10 can be prevented.

In this example, as shown in fig. 2, the skirt wall 3 is formed such that the thickness of a lower portion 14 located below the female screw 5 (female screw forming region 5A) is larger than the thickness of an upper portion 15 located above the female screw 5.

Here, the lower portion 14 is a portion that is continuous with the lower portion of the female thread 5 (female thread forming region 5A) in the skirt wall 3. The inner peripheral surface of the lower portion 14 extends to be spaced apart from the outer side (outer peripheral surface) as the lower side is closer. The lower portion 16 connected to the lower portion 14 has a larger inner diameter in the vertical direction as the inner diameter becomes closer to the lower side, and the vertical inner diameter change rate is larger than the vertical inner diameter change rate of the lower portion 14.

On the other hand, the upper portion 15 is a portion that is continuous with the upper portion of the female thread 5 (female thread forming region 5A) in the skirt wall 3. The inner peripheral surface of the upper portion 15 also extends to be farther from the outside (outer peripheral surface) as the lower side becomes. A corner portion 17 extending so that the inner peripheral surface and the outer peripheral surface are curved inward is connected to the upper portion of the upper portion 15.

Since the female screw 5 extends spirally on the inner peripheral surface of the skirt wall 3, the position and the vertical width of the female screw 5 (female screw forming region 5A) do not coincide with each other in the circumferential direction of the skirt wall 3, and differ according to the phase, and accordingly, the vertical widths of the lower portion 14 and the upper portion 15 also differ according to the phase.

In this way, in this example, since the thickness of the lower portion 14 is made larger than the thickness of the upper portion 15, the skirt wall 3 is less likely to be deformed with increased diameter than in the case where the thickness of the lower portion 14 is equal to or smaller than the thickness of the upper portion 15. Therefore, for example, in the case where a carbonated beverage is filled in the container, even if the internal pressure of the container is increased by the gas pressure from the carbon dioxide gas and a force pushing up the lid 1 is applied in a state where the male screw M1 is engaged with the female screw 5, the skirt wall 3 is less likely to expand in diameter as described above, and therefore, it is possible to prevent the engagement and disengagement of the skirt wall 3 from expanding to such an extent that the diameter can get over the male screw M1, and further, it is possible to prevent the occurrence of blow-off.

In addition, since the diameter of the skirt wall 3 is difficult to be enlarged, it is also possible to prevent occurrence of overrun (the internal thread of the cap overrides the external thread of the container mouth).

On the other hand, if the thickness of the portion of the female thread forming region 5A other than the female thread 5 is equal to or less than the thickness of the upper portion 15, there is a possibility that the diameter of the female thread forming region 5A is enlarged, and the prevention of the blow-off and the overrun cannot be sufficiently achieved, but in this example, the thickness of the portion of the skirt wall 3 other than the female thread 5 is increased downward from the upper portion 15 to the lower portion 14 (the region including the female thread forming region 5A), and therefore the prevention of the blow-off and the overrun can be sufficiently achieved. Note that, the two-dot chain line shown in the upper part of fig. 2 shows the cross-sectional shape of the portion of the skirt wall 3 other than the female screw 5.

The present invention is not limited to the above embodiments, and it is needless to say that various modifications can be made without departing from the scope of the present invention. For example, the following modifications are possible.

In the example of fig. 2, the thickness of the portion other than the female screw 5 increases at a constant rate from the upper end of the upper portion 15 to the lower end of the lower portion 14, but the ratio is not limited to this, and for example, the ratio may be changed halfway, or a portion other than the female screw 5 may be provided in which the thickness does not change in the vertical direction.

Further, a portion corresponding to neither the lower portion 14 nor the lowermost portion 16 may be provided between the lower portion 14 and the lowermost portion 16, or the lower portion 14 may be continued to the lower end of the skirt wall 3 without providing the lowermost portion 16.

A portion corresponding to neither the upper portion 15 nor the corner portion 17 may be provided between the upper portion 15 and the corner portion 17.

It is needless to say that the above modifications can be appropriately combined with each other.

Description of the symbols

1. Cover

2. Top wall

3. Skirt wall

4. Knurling groove

5. Internal thread

5A internal thread forming region

6. Middle foot

7. Annular rib

8. External foot

9. Tamper evident band

10. Annular weakening portion

11. Hook (fastening part)

12. Fitting part

13. Inclined part

14. Lower part

15. Upper part of the body

16. The lowest part

17. Corner part

51. Cover

52. Internal thread

M container mouth

M1 external thread

M2 Ring-shaped protrusion (engaged part)

Claims

1. A cap to be attached to a container mouth portion so as to cover the container mouth portion, the cap comprising:

a top wall; and

a substantially cylindrical skirt wall extending downward from an outer peripheral portion of the top wall,

the skirt wall is provided with a female screw to be screwed with a male screw formed on the outer periphery of the container mouth,

in the skirt wall, the wall thickness of a lower part positioned below the internal thread is larger than the wall thickness of an upper part positioned above the internal thread,

in the skirt wall, an inner peripheral surface of the lower portion extends to be farther away from the outer peripheral surface toward a lower side, an inner diameter of a lowermost portion continuing to a lower side of the lower portion becomes larger toward the lower side, and a vertical inner diameter change rate is larger than a vertical inner diameter change rate of the lower portion,

the wall thickness of the portion other than the female screw is larger toward the lower side and the inner diameter of the lowermost portion is larger toward the lower side in the region from the upper portion to the lower portion over the entire circumference of the skirt wall,

an area in which the vertical width of the lowermost portion is larger than the vertical width of the lower portion is formed.

2. The lid as set forth in claim 1, wherein the skirt wall extends such that the inner peripheral surface of the lower portion is farther from the vertical outer peripheral surface toward the lower side.

3. The cap according to claim 1 or 2, wherein a tamper band is connected to a lower portion of the skirt wall by an annular weakened portion, and an engagement portion is provided on an inner peripheral side of the tamper band, the engagement portion being configured to be engageable from below with an annular protrusion formed on an outer periphery of the container mouth portion below the male screw.