WO2020179607A1

WO2020179607A1 - Synthetic resin cap

Info

Publication number: WO2020179607A1
Application number: PCT/JP2020/007988
Authority: WO
Inventors: 靖文黒岩; 伸生川村; 広則見城; 淳史小野; 慎吾梅木
Original assignee: 日本山村硝子株式会社
Priority date: 2019-03-07
Filing date: 2020-02-27
Publication date: 2020-09-10
Also published as: CN113423648B; JP7434275B2; JPWO2020179607A1; KR20210129117A; CN113423648A

Abstract

Provided is a synthetic resin cap capable of improving sealability. A synthetic resin cap 1 is provided with: a top wall 2; and a skirt wall 3 that extends downward from the outer periphery of the top wall 2, and that has a female thread 5 to be screwed with a male thread M1 of a container mouth M, wherein an annular shank 6 tightly adhered to the inner circumferential surface of the container mouth M is integrally formed at the bottom surface of the top wall 2, and the longitudinal cross-section of the outer peripheral surface of a top part 13 extending from a base portion 12 of the shank 6 to a center portion 14 has a curved shape recessed toward the inner side of the shank 6.

Description

Synthetic resin cap

The present invention relates to, for example, a synthetic resin cap attached to the mouth of a container that stores contents such as beverages.

As a conventional synthetic resin cap, as shown in FIGS. 3A and 3B, a container mouth portion is formed on a top plate portion 51 of a cap having a top plate portion 51 and a tubular portion 52 hanging from the peripheral edge thereof. An annular inner seal protrusion 53 fitted into the container M, an annular open end seal protrusion 54 that abuts on the open end surface of the container mouth M, and an annular outer seal protrusion 55 that abuts on the outer surface of the container mouth M. It is known that the inner seal protrusion 53 is formed so as to come into contact with the inner surface of the container mouth M in a state of being slightly elastically curved inward (Patent Document 1).

In such a synthetic resin cap, the inner seal protrusion 53 is said to come into contact with the inner surface of the container mouth portion M with sufficient pressing force.

Japanese Patent No. 5977937

However, it is considered that the conventional synthetic resin caps mentioned above have room for improving the sealing performance.

The present invention has been made in consideration of the above-mentioned matters, and an object of the present invention is to provide a synthetic resin cap capable of improving the sealing property.

In order to achieve the above object, the synthetic resin cap according to the present invention includes a top wall and a skirt wall having a female screw extending downward from the outer peripheral portion of the top wall and screwing into the male screw of the container mouth portion. A synthetic resin cap integrally formed on the lower surface of the top wall with an annular inner foot that closely adheres to the inner peripheral surface of the container mouth, The vertical cross-sectional shape of the outer peripheral surface of the upper portion extending toward the portion has a curved shape that dents toward the inside of the middle leg (claim 1).

In the synthetic resin cap, the vertical cross-sectional shapes of the inner peripheral surface and the outer peripheral surface of the base portion of the middle foot are curved so as to be recessed toward the upper side of the middle foot, respectively, from the outer peripheral surface of the root portion. The inner peripheral surface may be gently curved (claim 2).

In the synthetic resin cap, the vertical cross-sectional shape of the outer peripheral surface of the base portion of the middle foot is curved toward the upper side of the middle foot, and the vertical section of the inner edge of the tip of the container mouth portion. It may be sharper than the surface shape (claim 3).

In the synthetic resin cap, on the lower surface of the top wall, an annular rib located on the outer peripheral side of the middle leg and in close contact with the upper end surface of the container mouth, and an annular rib located on the outer peripheral side of the annular rib, said. An annular outer leg that is in close contact with the outer peripheral surface of the container mouth is integrally formed, and a seal point having the maximum outer diameter is formed at the central portion in the vertical direction on the outer peripheral surface of the middle leg. The axial distance from the lower end of the annular rib to the seal point of the middle foot may be 1.5 mm or more and 3.5 mm or less (claim 4).

In the present invention, a synthetic resin cap capable of improving the sealing property can be obtained.

That is, in the synthetic resin cap of the present invention, when capping the container mouth portion, the middle leg with an elaborate shape of the upper outer peripheral surface easily adheres to the inner edge of the tip of the container mouth portion, and the sealing property is improved accordingly. be able to.

With the synthetic resin cap of the invention according to

claims

2 and 3, the above-mentioned effect of improving the sealing performance can be enhanced by devising the shape of the root of the metatarsal.

In the synthetic resin cap of the invention according to claim 4, the prevention of airtight leakage can be improved by devising the position of the seal point of the middle foot.

(A) and (B) are a vertical sectional view and an enlarged explanatory view of a main part which substantially show the structure of the synthetic resin cap which concerns on one Embodiment of this invention. It is explanatory drawing which shows roughly the structure of the principal part of the said synthetic resin cap. (A) is a vertical sectional view showing a conventional synthetic resin cap, and (B) is an enlarged vertical sectional view showing a main part thereof.

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

The synthetic resin cap (hereinafter referred to as a cap) 1 shown in FIGS. 1 (A) and 2 is used by being attached to the mouth M (see FIG. 2) of a container such as a PET bottle, and is used for compression. It is integrally molded of polyethylene by molding or injection molding. The material for forming the cap 1 is not particularly limited, and polypropylene or the like is preferably used in addition to the polyethylene used in the present embodiment.

Further, the cap 1 has a top wall 2 having a substantially circular shape in a plan view and a substantially cylindrical skirt wall 3 extending downward from an outer peripheral portion of the top wall 2. Here, 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 is connected to a male screw M1 (see FIG. 2) formed on the outer periphery of the container mouth. It is possible.

Then, when the cap 1 is attached to the container mouth M by rotating the cap 1 so that the female screw 5 of the skirt wall 3 is coupled to the male screw M1 of the container mouth M, an annular shape continuous with the inner surface (lower surface) of the top wall 2 is formed. The middle leg (inner ring) 6, the annular rib 7, and the annular outer leg (outer ring) 8 are in close contact with the container mouth portion M, whereby the container mouth portion is sealed. That is, when the cap 1 is attached to the container mouth M, the middle foot 6 is inserted into the container mouth M and comes into close contact with the inner peripheral surface of the container mouth M, and the annular rib 7 is the container mouth M. The outer leg 8 is configured to be in close contact with the annular upper end face and the outer peripheral face of the container mouth M.

In addition, the cap 1 is a pill fur-proof cap having a function of proving that it has not been opened (the cap has never been opened), and when the unopened cap 1 attached to the container mouth M is opened (first When the cap 1 is rotated so that the connection between the male screw M1 and the female screw 5 is released, the cap 1 is detached from the container opening M, but the tamper evidence connected to the lower part of the skirt wall 3 The band (hereinafter, simply referred to as “band”) 9 is configured to remain in the container opening M.

That is, a band 9 is connected to the lower part of the skirt wall 3 via an annular weakening portion 10 extending over the entire circumference of the skirt wall 3, and the annular weakening portion 10 is within the boundary between the skirt wall 3 and the band 9. It is composed of a plurality of bridges 10a existing on the circumferential side and slits 10b extending in the circumferential direction of the skirt wall 3 and the band 9 so as to vertically define the skirt wall 3 and the band 9, and the bridge 10a is acted with a predetermined force. A part (outer peripheral portion) of the bridge 10a is also cut by the slit 10b so as to be broken when pulled.

Further, on the inner peripheral side of the band 9, a plurality (in this example, eight) of locking pieces (flaps) 11 projecting inward are provided at intervals in the circumferential direction. Each locking piece 11 has an annular protrusion (bead portion) M2 (see FIG. 2) formed below the male screw M1 on the outer circumference of the container mouth portion M with the cap 1 attached to the container mouth portion M. It is located substantially downward and is locked to the annular protrusion M2 by the opening operation. That is, the locking piece 11 is configured to be able to be locked to the annular protrusion M2 from below, and when the seal is opened, the cap body portion (skirt wall 3 and top wall 2) above the annular weakening portion 10 is the container mouth portion. The band 9 which is separated from M and is below the annular weakening portion 10 remains in the container mouth portion M, and the annular weakening portion 10 is broken accordingly.

Here, the band 9 is integrally molded with the cap main body (skirt wall 3 and top wall 2), and the locking piece 11 provided on the band 9 projects downward when the cap 1 is molded, but the container mouth portion M When the cap 1 is mounted on the cap 1, it is pushed up by the annular protrusion M2 and inverted, and is in a state of protruding upward as shown in FIGS. 1(A) and 2.

Then, in the present embodiment, as shown in FIG. 1 (B), the outer peripheral surface of the middle foot 6 has an outer root portion 12 and an outer upper portion from the root side to the tip side when the vertical cross-sectional shape thereof is observed. It can be divided into four regions, namely, 13, an outer central portion 14, and an outer lower portion 15.

The outer root portion 12 has a vertical cross-sectional shape that is curved so as to have a constant radius of curvature from the position inside the annular rib 7 on the lower surface of the top wall 2 and to be recessed upward of the middle foot 6. ing. Further, the outer root portion 12 is curved downward from the upper end thereof so that the outer diameter becomes smaller toward the lower side, and conversely, at the lower portion, the outer root portion is curved such that the outer diameter becomes larger toward the lower side. ..

The outer upper part 13 has a vertical cross-sectional shape that is curved from the lower end of the outer root 12 so as to have a constant radius of curvature and is recessed toward the inner side of the middle foot 6.

The outer central portion 14 has a vertical cross-sectional shape that is curved so as to have a constant radius of curvature from the lower end of the outer upper portion 13 and to be convex (protruding) toward the outside of the middle foot 6. There is. Further, a seal point 14a having a maximum outer diameter of the middle foot 6 is provided at the central portion of the outer central portion 14 in the vertical direction, and the outer central portion 14 is lowered from the upper end toward the seal point 14a. It is curved so that the outer diameter becomes larger toward the side, but conversely, it is curved so that the outer diameter becomes smaller toward the lower side from the seal point 14a.

The outer lower portion 15 has a vertical cross-sectional shape extending linearly from the lower end of the outer central portion 14 so as to have a constant inclination angle and the outer diameter becomes smaller toward the lower side.

Further, in the present embodiment, as shown in FIG. 1 (B), the inner peripheral surface of the middle foot 6 has the inner root portion 16 and the inner side from the root side to the tip side when the vertical cross-sectional shape thereof is observed. It can be divided into two regions of the body part 17.

The medial root portion 16 has a vertical cross-sectional shape that is curved so as to have a certain radius of curvature from the position inside the midfoot 6 on the lower surface of the top wall 2 and to be recessed upward of the midfoot 6. ing. Further, the inner root portion 16 is curved such that the inner diameter thereof becomes larger toward the lower side from the upper end thereof toward the lower side.

The inner main body portion 17 has a vertical cross-sectional shape extending linearly from the lower end of the inner root portion 16 so as to have a constant inclination angle (1 ° in this example) and to increase the inner diameter toward the lower side. doing.

Here, in the vertical cross-sectional shape of the middle leg 6, the radius of curvature of the inner root portion 16 is larger than the radius of curvature of the outer root portion 12 (the inner root portion 16 is gently curved than the outer root portion 12). ), the radius of curvature of the outer central portion 14 is larger than that of the inner root portion 16, and the radius of curvature of the outer upper portion 13 is larger than that of the outer central portion 14. Further, in the middle foot 6, the vertical width of the outer root part 12 is larger than the vertical width of the inner root part 16, and the outer root part 12 extends below the inner root part 16. While the vertical width of the outer upper portion 13 is larger than the vertical width of the portion 12, the vertical width of the outer central portion 14 is smaller than the vertical width of the outer root portion 12 and further the vertical width of the inner root portion 16.

In the middle foot 6 configured as described above, the vertical cross-sectional shape of the outer upper portion 13 occupying the largest area above the seal point 14a on the outer peripheral surface thereof is curved toward the inside of the middle foot 6. Therefore, when the cap 1 is attached to the container opening M (when capping), the outer upper portion 13 is easily brought into close contact with the inner edge of the tip of the container opening M, and the sealing performance can be improved accordingly. The effect of this effect is that the upper part of the outer peripheral surface of the middle foot 6 (above the seal point 14a) is not provided with a portion extending linearly in the vertical direction, and the upper part of the inner peripheral surface is provided with a portion extending linearly (inner body). This is further enhanced by providing the portion 17), that is, by not providing a portion extending in parallel inside and outside the upper part of the middle foot 6.

Further, the vertical cross-sectional shapes of the outer root portion 12 and the inner root portion 16 of the middle foot 6 are curved so as to be recessed toward the upper side of the middle foot 6, respectively, and the inner root portion 16 is larger than the outer root portion 12. Since it is gently curved, this also enhances the above-described effect of improving the sealing performance.

Here, the vertical cross-sectional shape of the outer root portion 12 of the middle leg 6 is such that the radius of curvature of the vertical cross-sectional shape of the outer root portion 12 is made smaller than the radius of curvature of the vertical cross-sectional shape of the inner edge of the tip of the container mouth portion M. The above-mentioned effect of improving the sealing property is also enhanced by making the shape of the inner edge of the tip of the container mouth M curved steeper than the vertical cross-sectional shape.

Further, it is preferable that the axial distance d1 from the lower end of the annular rib 7 to the seal point 14a of the middle foot 6 is 1.5 mm or more and 3.5 mm or less. If it is less than 1.5 mm, the seal point 14a is too close to the tip of the container mouth M, and conversely, if it is more than 3.5 mm, the upper part of the middle foot 6 from the seal point 14a tends to bend. Is also prone to airtight leakage.

Further, in the middle foot 6, the outer lower portion 15 is a portion that receives contact with the container mouth portion M during capping, and basically, the container mouth portion M is assumed to contact the center position 15a in the vertical direction. It is a place. Then, in the present embodiment, the axial distance d2 from the seal point 14a to the central position 15a in the middle foot 6 is made larger than the axial distance d3 from the central position 15a to the lower end of the middle foot 6. As a result, the amount of material used is reduced by downsizing the middle leg 6, and the lower part of the middle leg 6 is thickened to some extent to prevent it from breaking. Moreover, in the present embodiment, the center position 15a is located outside (outer peripheral side) of the minimum outer diameter position of the middle foot 6, and is set so as not to extend to the outer peripheral side of the outer root portion 12, so that the middle position during capping The foot 6 is likely to be deformed over a wide range from its root to the lower side, stress is not concentrated, and it is possible to make it less likely to receive a large resistance.

It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that the present invention can be variously modified and implemented without departing from the gist of the present invention. For example, the following modifications can be mentioned.

In the above embodiment, the inner main body portion 17 has a vertical cross section extending linearly from the lower end of the inner root portion 16 so as to have a constant inclination angle (1 °) and to increase the inner diameter toward the lower side. Although it has a shape and makes it easy to perform die cutting, the present invention is not limited to this, and the inner main body 17 may extend parallel to the axial direction of the cap 1, for example.

In the examples of FIGS. 1A and 2, a flap (a structure in which the lower portion of the band 9 is folded inward) 11 is provided, but instead of the flap 11, a hook (inner peripheral side of the band 9) is provided. (Provided with a portion having a protruding portion) may be provided so as to be engaged with the annular protrusion M2 of the container mouth portion M.

In the examples of FIGS. 1A and 2, the lower surface of the top wall 2 connected to the inner peripheral side of the middle foot 6 and the lower surface of the top wall 2 connected to the outer peripheral side are substantially the same height, but the height is limited to this. Alternatively, the former may be located above or below the latter.

Needless to say, the above modified examples may be appropriately combined.

1 Cap 2 Top Wall 3 Skirt Wall 4 Knurled Groove 5 Female Thread 6 Middle Foot 7 Annular Rib 8 Outer Foot 9 Tamper Evidence Band 10 Annular Weakened Section 11 Locking Piece 12 Outer Root 13 Outer Upper 14 Outer Central 14a Seal Point 15 Outer Lower part 16 Inner root part 17 Inner body part 51 Top plate part 52 Cylindrical part 53 Inner seal protrusion 54 Open end seal protrusion 55 Outer seal protrusion d1 Axial distance d2 Axial distance d3 Axial distance M Container mouth M1 Male screw M2 annular protrusion (engaged part)

Claims

A top wall and a skirt wall that extends downward from the outer peripheral portion of the top wall and has a female screw that is screwed into a male screw of the container mouth portion are provided. A synthetic resin cap in which an annular middle leg that adheres to the surface is integrally formed.
A synthetic resin cap in which a vertical cross-sectional shape of an outer peripheral surface of an upper portion extending from a root portion to a central portion of the middle foot is curved so as to be recessed toward the inner side of the middle foot.
The vertical cross-sectional shape of the inner peripheral surface and the outer peripheral surface of the root of the middle foot has a curved shape that is recessed upward of the middle foot,
The synthetic resin cap according to claim 1, wherein an inner peripheral surface of the root portion is curved more gently than an outer peripheral surface thereof.
The vertical cross-sectional shape of the outer peripheral surface of the base of the middle foot is curved toward the upper side of the middle foot, and is steeper than the vertical cross-sectional shape of the inner edge of the tip of the container mouth. The synthetic resin cap according to claim 1 or 2.
On the lower surface of the top wall, an annular rib located on the outer peripheral side of the middle leg and in close contact with the upper end surface of the container mouth portion, and an annular rib located on the outer peripheral side of the annular rib and on the outer peripheral surface of the container mouth portion. It is formed integrally with the ring-shaped outer foot that sticks,
Further, on the outer peripheral surface of the middle foot, a seal point having a maximum outer diameter is formed in a central portion in the vertical direction,
The synthetic resin cap according to any one of claims 1 to 3, wherein an axial distance from a lower end of the annular rib to the seal point of the middle leg is 1.5 mm or more and 3.5 mm or less.