JP2000247346A - Resin cap - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin cap having a superior sealing performance which can be opened easily and surely, showing a superior cap-in operation and molding characteristic and can easily take a balance between opposing performances such as sealing characteristic and opening characteristic. SOLUTION: A resin cap is comprised of a top plate 2 having at its inner surface a sealing engagement part 10 with an opening part of a container; and a skirt part 3 having at the inner surface an inner diametric engagement protrusion 4 engaged with an outer circumferential surface of the opening part of the container and having at a lower part of an outer surface side a cap opening tab 11 protruded in an outer diametric direction. The engagement protrusion 4 is comprised of an upper part 6 of which diameter is reduced inwardly to reach up to the top part; and a lower part 9 including a cap-in guide section 7 of which diameter is increased from the top part in a downward direction and including a recess 8 of which upper end edge is positioned at the top part and positioned below the top part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin cap excellent in opening property, and more particularly to a resin cap suitably applied to a milk bottle.

[0002]

2. Description of the Related Art Hitherto, a milk bottle has been provided with a paper cap fitted in a bottle mouth and a cover made of a resin film applied thereon. In such a cap, a special opening tool is required to easily open the cap, and a cap that can be easily opened without the opening tool has been demanded. In order to solve such a problem, an inner plug is formed at the center of the top plate to protrude downward to fit inside the container mouth, and a ridge engaging with the container mouth is provided on the inner surface of the skirt. In addition, there has been proposed a resin cap characterized in that breakable thin portions are provided on both sides of an opening tab (Japanese Utility Model Publication No. 47-13109). This cap is capable of removing the cap from the container opening by breaking the thin section by pulling up the opening tab and breaking the cap, and does not require a special opening tool. Is preferred.

[0003]

However, in such a cap, a certain amount of force is required to break the skirt portion along the thin portion, and the contents may be spilled when the cap is opened. There is also. In particular, when the content is applied to a wide range of consumers from children to the elderly, such as milk, it is necessary to easily and securely open the bottle without applying force. is there. The resin cap configured as described above is fitted by sealing the container by filling the contents with a stopper and engaging a ridge provided on the inner surface of the skirt portion of the cap with a concave portion of the container mouth. I do. At this time, in general, in order to improve the sealing performance of the cap and improve the preservability of the contents, the amount of protrusion of the ridge provided on the inner surface of the skirt portion of the cap is increased to fit tightly into the container mouth. Although the fitting is performed, if the fitting becomes strong, the opening force increases, and the opening property becomes a problem. Further, when the thin portion is excessively reinforced to prevent the thin portion from being broken at the time of tapping, there is also a problem that opening the plug becomes extremely difficult, and it becomes difficult to control the dimensions of the thin portion. .

Accordingly, an object of the present invention is to provide an excellent sealing performance and to easily and reliably open the plug, and also excellent in the plugging property and the moldability, and to balance the opposing performances of the sealing property and the opening property. An object of the present invention is to provide a resin cap which can be easily taken.

[0005]

According to the present invention, a top plate portion provided with a sealing engagement portion with a container mouth portion on the inner surface side, and a radially inwardly engaging portion with the outer peripheral surface of the container mouth portion on the inner surface side. And a skirt portion provided with a locking tab protruding radially outward on a part of the lower side of the outer surface side, wherein the locking protruding portion faces downward. It is characterized by comprising an upper part whose diameter is reduced and reaches a top part, and a lower part comprising a stopper guide part whose diameter increases from the top part downward and a notch part whose upper end edge is located below the top part. A resin cap is provided.

[0006] In the resin cap of the present invention, the locking projection has a notch except that the notch portion is adjacent to the tapping guide portion in the circumferential direction, and except for the opening tab. And each of the locking projections has a stopper guide at least at an end in the circumferential direction or in the vicinity thereof, and a notch between the stopper guides. In addition, a window-shaped concave portion is provided on the outer surface side of the skirt portion except for the lower end side of the skirt portion in a circumferential direction, and the window-shaped concave portion is provided with the stopper guide portion and the radial direction. It is particularly preferable that they are provided in a positional relationship overlapping each other.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Operation] In order to improve the sealing performance of the cap, the diameter of the cap at the top of the above-mentioned locking projection must be small, that is, the locking projection protrudes largely inward and the container opening is formed. It is desirable that the outer peripheral surface is firmly engaged with the outer peripheral surface. On the other hand, if the locking projections protrude largely inward, the skirt portion of the cap becomes thicker and lacks flexibility, resulting in poor openability. From such a viewpoint, the resin cap of the present invention is characterized in that the upper and lower locking projections each have an upper part whose diameter decreases downward and reaches the top and a lower part whose diameter increases from the top and lowers below the skirt part. The lower stoppering guide portion retains the locking force with the container opening, and the notch portion is provided below the vicinity of the top of the locking projection, so that the function of the locking projection is not impaired. The flexibility is given to the cap to improve the openability.

In addition, a stopper guide portion whose diameter increases downward from the top and a notch portion for partially reducing the thickness of the skirt portion are provided below the locking projection, so that the container mouth portion is provided. The skirt is expanded in the radial direction, the cap is smoothly introduced into the container mouth along the stoppering guide, and the upper portion of the locking projection and the outer peripheral surface of the container mouth (the outer peripheral portion of the container mouth protrudes. Is formed, the lower surface of the projection is engaged, and breakage of the cap at the time of tapping is effectively prevented.

[Embodiment] A preferred embodiment of a resin cap according to the present invention will be described with reference to the accompanying drawings. Note that the embodiments described below are described as being applied to milk bottles that are generally distributed, but the present invention is of course not limited to this. FIGS. 1A and 1B are for explaining the outline of the resin cap of the present invention, in which FIG. 1A is a bottom view, FIG. 1B is a side sectional view taken along the line XX of FIG. (C) is a side view of (A).

The resin cap of the present invention generally designated by 1 comprises a top plate portion 2 and a skirt portion 3 hanging down from an edge of the top plate portion 2, and an inner surface of the skirt portion 3 has a locking projection 4.
Are provided. As will be described in detail later, the locking projection 4 includes an upper portion 6, a stopper guide portion 7, and a lower portion 9 having a notch 8. On the inner surface of the top plate 2, an inner plug 10 is provided in an annular shape to be fitted inside a container opening (not shown). Further, the skirt portion 3 is provided with an opening tab 11 for opening. Further, a plurality of window-shaped concave portions 12 are provided on the outer surface side of the skirt portion 3 in the circumferential direction except for the vicinity of the lower end of the skirt portion 3.

FIGS. 2 and 3 are enlarged side sectional views for explaining in detail the locking projections 4 of the cap shown in FIG. The locking projection 4 is composed of an upper part 6 in a region indicated by m and a lower part 9 in a region indicated by n with the top part 5 as a boundary. The upper part 6 is reduced in diameter downward to reach the top part 5 and the lower part 9
Is a capping guide portion 7 whose diameter increases downward from the top portion 5.
And a notch 8 adjacent to the stoppering guide 7 in the circumferential direction and having an upper edge located at the top 5. Although the upper end edge of the notch 8 shown in FIGS. 2 and 3 is located at the top 5, the purpose of the notch can be achieved if the thickness below the thickest top 5 is reduced. The top edge of the section need not be the top.

As shown in FIG. 1A, it is preferable that a plurality of the locking projections 4 are provided in the circumferential direction except for the opening tab 11.
That is, flexibility is imparted to the skirt portion of the opening tab 11 by not providing the locking projection 4 at the portion corresponding to the opening tab 11 and keeping the skirt portion of this portion thin. Then, the cap can be easily deformed by pushing up the opening tab 11 upward, and the opening property can be improved. Further, by providing the plurality of locking projections 4 in the circumferential direction without being continuous, a thin portion 13 is formed between the locking projections, and flexibility is imparted to the entire skirt portion. It becomes possible to improve the pluggability and the pluggability.

Further, each of the locking projections 4 has a tapping guide at least at an end in the circumferential direction or in the vicinity thereof, and has a notch between the tapping guides. Is preferred. That is, as is clear from FIGS. 1A and 1B, the locking projections 4 a provided on both sides of the opening tab 11 form the notch 8 between the stoppering guides 7 a and 7 b. Have. The stopper projections 4b at portions other than both sides of the opening tab 11 are provided with stoppering guides 7a and 7b at both ends and a stoppering guide 7c and three stoppering guides at the center. Thus, two notches 8a and 8b are formed. As described above, since the notch portion is sandwiched between the stoppering guide portions, the cap is smoothly introduced into the container mouth along the stoppering guide portions on both sides at the time of stoppering, and the notch is formed. The upper end of the part does not become a resistance.

In the specific example shown in FIG. 1, the stopper projections on both sides of the opening tab are provided with stopper guides only at both ends, one notch is provided therebetween, and the other stoppers are provided. The projections are provided with stoppering guides at both ends and at the center, and two notches are provided. However, the combination of these notches is optional, and all of the protrusions may have one notch or may alternately It is of course possible to provide three notches. Further, in addition to dispersing as described above, the locking projection is provided in a U-shape excluding a portion of the annular or opening tab, and a plurality of stoppering guides and notches are provided at a lower portion. Is also good.

In FIG. 4, (A) shows a bottom view of the cap similarly to FIG. 1 (A), and (B) shows (A).
FIG. 3 is a side cross-sectional view taken along the line YY in FIG. 3, and FIG. As described above, in the present invention, it is particularly preferable that the window-shaped concave portion 12 is provided on the outer surface of the skirt portion 3 (FIG. 1C). By providing the window-shaped concave portion 12, a thin portion is provided in the skirt portion to give flexibility to the cap, to improve the opening property, and to facilitate the radial expansion of the cap at the time of plugging. Becomes possible. The shape of the window-shaped concave portion 12 is not particularly limited to the shape shown in FIG. 1C, but from the viewpoint of preventing the cap from being damaged by stoppering, and because the lower end of the skirt portion is used as a holding portion when the mold is removed during molding. From the viewpoint that it is necessary to secure a certain thickness at the lower end of the skirt portion, it is preferable that a plurality of the skirt portions are provided in the circumferential direction except for the lower end. Further, FIG.
As shown in (C), the window-shaped recess 12 is provided with the stopper guide portion 7.
It is preferably provided at a position that overlaps with the radial direction. Since the portion provided with the stoppering guide portion 7 is thick, by providing a concave window portion in this portion,
It is possible to reduce the thickness of the thick part in the skirt.

FIG. 5 is an enlarged sectional side view for explaining the opening tab 11 of the cap shown in FIG. The opening tab 11 includes a flange portion 14 and a plurality of ribs 15 for reinforcing the flange portion 14.
A ridge 16 for hooking a finger is provided at the lower end of the front end of the head. In the present invention, a thin skirt portion can be easily opened by stretching the thin skirt portion by applying a finger to the vicinity of the ridge 16 below the flange portion 14 of the opening tab 11 and pushing it upward. Can be. Since the cap of the present invention does not open by breaking the cap, it can be re-opened, for example, when it is left behind.

FIG. 6 is a side sectional view showing a case where the resin cap 1 of the present invention is applied to a milk bottle 20.
FIG. 7 is a side sectional view showing an enlarged portion of a mouth portion 21 of the milk bottle in FIG. 6. 6 and 7, the cap 1 is
The skirt portion 3 and the inner plug 10 are fitted into the mouth 21 of the milk bottle, and the outer surface of the inner plug, the inner surface of the skirt and the inner surface of the top plate are in close contact with the bottle opening 21 to maintain the sealing of the cap. As shown in FIG. 7, when the cap 1 is fitted into the bottle mouth 21, the region Q1 on the outer surface side of the inner plug and the region Q2 on the inner surface side of the skirt portion which overlap with the bottle mouth shape in FIG. At the same time, the inner plug is elastically deformed so that it can be pushed radially inward and the skirt portion can be pushed radially outward. Therefore, in the area Q, when the cap is applied, the cap is pressed against the container mouth by the force in the direction opposite to the direction in which the cap is spread. It is kept high. The milk bottle shown in FIGS. 6 and 7 is an example of a container to which the cap of the present invention is applied. According to this example, no step is provided on the outer peripheral surface of the mouth of the milk bottle, and the milk bottle is locked. Engagement is engaged by locking the outer peripheral surface inclined portion of the mouth, but when a protrusion is provided on the outer peripheral surface of the container mouth,
Of course, the lower surface of the projection and the upper portion of the locking projection are engaged to seal.

In the embodiment shown in FIGS. 1 to 7, the sealing engagement part provided on the cap is an inner plug 10,
This allows the sealing performance of the cap to be kept high, but is not limited to this. For example,
Conventionally known sealing engagement means, such as providing an annular seal member in contact with the tip of the container mouth on the inner surface of the cap top plate, can be employed.

In the locking projection of the cap of the present invention, the shape of the notch can be variously changed. FIG. 8A is an enlarged sectional view showing the shape of the cutout portion of the cap shown in FIGS. 1 to 7, and FIGS. 8B to 8E are enlarged views showing another example of the cutout portion. It is sectional drawing. (A) is as described above, but (B) is a cutout 8 formed by forming a rectangular recess in the radial direction below the top 5 of the lower portion 9 of the locking projection. A portion 17 serving as a stoppering guide is also provided below the notch 8. According to this aspect, the engagement between the cap and the container can be made stronger, and the sealing performance is improved.

(C) is a cutout 8 formed in the lower portion 9 of the locking projection by extending a recess extending from the lower end of the cap to the vicinity of the top 5 in the axial direction.
As in the case of (A), the mold can be easily removed at the time of molding and the moldability is excellent, and the portion of the cap that projects inward in the radial direction is not cut, so that the container has good sealing performance. Note that, in this mode, as in the case of FIG.
Since the lower surface 17 of the 8 serves as a stoppering guide portion, it can be provided over the entire circumferential direction corresponding to the locking projection without providing an independent stoppering guide portion, but the stoppering property is further improved. In order to improve the performance, it is more preferable to provide the stoppering guide portion independently from the top portion 5 to the lower end of the skirt portion as in the case of (A). (D) is obtained by dispersing the notched portions of (C) in the radial direction. According to this embodiment, the same effect as (C) can be obtained, and (C)
It is preferable to further provide an independent stoppering guide similar to the above. Further, (E) shows a shape in which the cutout portion has a substantially semicircular shape, and in this embodiment, the same effect as (A) can be obtained.

The resin cap of the present invention can be integrally formed by injection molding or compression molding using a synthetic resin such as polyethylene. In general, in the case of a synthetic resin cap, a punching die is used on the inner surface side of the cap,
The undercut on the inner surface of the cap is preferably small, but in the present invention, no undercut other than the locking projection is formed. When the mold is to be cut, a certain thickness is required at the lower end of the skirt portion. However, in the cap of the present invention, the window-shaped recess is also provided except for the lower end of the cap, so that the die can be easily cut. And excellent in moldability.

[0022]

In the resin cap of the present invention, a stopper guide portion whose diameter increases downward from the top and a notch portion for partially thinning the skirt portion are provided below the locking projection. This makes it possible to impart flexibility to the skirt portion without weakening the engaging force of the locking projection, thereby enabling easy and secure opening without requiring any force for opening, and sealing. It is possible to easily balance the conflicting performances of the property and the opening property. In addition, due to the presence of the stoppering guide, the cap is smoothly introduced into the container mouth along the stoppering guide, and the upper part of the locking projection and the outer peripheral surface of the container mouth are locked, and the cap is pressed. Breakage of the cap in the stopper can be effectively prevented. Furthermore, the locking projections are provided dispersed in the circumferential direction, and a thin portion is formed between the locking projections, so that the air in the cap is easily released at the time of plugging, and the resistance at the time of plugging is reduced. Can be reduced, and the plugging property is excellent. Furthermore, since the engaging member such as a locking projection and an inner plug is firmly fitted to the container mouth and has excellent sealing performance, not only does the content not leak, but also the content is prevented from leaking. It is suitable to be used for a glass container which is excellent in preservability, especially excellent in preservability such as a milk bottle.

[Brief description of the drawings]

FIG. 1 shows an example of a resin cap of the present invention, in which (A) is a bottom view, (B) is a side sectional view, and (C) is a side view.

FIG. 2 is a partially enlarged side sectional view of FIG. 1;

FIG. 3 is a partially enlarged side sectional view of FIG. 1;

4A and 4B are views of the resin cap shown in FIG. 1 viewed from another direction, wherein FIG. 4A is a bottom view, FIG.
(C) is a partially enlarged view of a P part of (A).

FIG. 5 is a partially enlarged side sectional view of FIG. 1;

FIG. 6 is a side sectional view showing a state in which the resin cap of the present invention is applied to a container mouth.

FIG. 7 is a partially enlarged side sectional view of FIG. 6;

FIG. 8 is a partially enlarged side sectional view showing another example of the shape of the notch in the resin cap of the present invention.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tetsuo Kubo 2-12 Nagatoro, Hiratsuka-shi, Kanagawa F-term in Hiratsuka Plant of Japan Crown Cork Co., Ltd. 3E084 AA04 AA12 AA32 AB01 BA01 CA01 CC03 DA01 DB09 DB13 DC03 EA04 EC03 FA09 FC09 GA08 GB12 GB17 HA03 HB01 HC03 HD04

Claims (7)

[Claims] 1. A top plate portion provided on the inner surface side with a sealing engagement portion with a container mouth portion, and a projection portion for inward locking to a radially inner side to be locked on the outer peripheral surface of the container mouth portion on the inner surface side, and In a resin cap comprising a skirt portion provided with an opening tab protruding radially outward at a part below the outer surface side, the locking projection has an upper part whose diameter is reduced downward and reaches the top. A cap made of resin, comprising: a stopper guide portion having a diameter increasing downward from the top portion; and a lower portion having a top portion or a cutout portion located below the top portion. 2. The resin cap according to claim 1, wherein the notch portion is circumferentially adjacent to the stoppering guide portion. 3. The resin-made resin according to claim 1, wherein a plurality of the locking protrusions are provided in a circumferential direction except for a part of an opening tab. cap. 4. Each of the plurality of locking projections has a tapping guide at least at an end in the circumferential direction or in the vicinity thereof, and has a notch between the tapping guides. The resin cap according to claim 3, wherein: 5. The resin cap according to claim 1, wherein the sealing engagement portion is an inner plug. 6. The method according to claim 1, wherein a plurality of window-shaped recesses are provided on an outer surface side of the skirt portion except for a lower edge of the skirt portion in a circumferential direction. The resin cap according to any one of the above. 7. The resin cap according to claim 6, wherein the window-shaped concave portion is provided in a positional relationship overlapping the stoppering guide portion in a radial direction.