CN114423688B - build - Google Patents

Abstract

The invention provides a cover capable of inhibiting the increase of the bolt opening torque and the bolt closing torque and realizing the improvement of the air tightness. The cover has: a housing (1) having a top wall (3) and a side wall (4) depending from the periphery of the top wall (3), wherein an internal thread (5) that is screwed with an external thread (M1) of a container mouth (M) is formed in the side wall (4); and a gasket (2) that is held in the case (1) and seals the container mouth (M), wherein the gasket (2) is provided with: a top plate (10) that covers the container mouth (M); and a middle leg (11) which is connected to the lower surface of the top plate (10) and is tightly attached to the inner peripheral surface of the container mouth (M), wherein the top plate (10) pressed downward by the top wall (4) is elastically deformed when the closure is closed, and the central part of the top plate (10) is displaced downward more than the peripheral part.

Description

build

Technical Field

The present invention relates to a cap having a two-piece structure including, for example, a shell and a gasket which is separate from the shell.

Background technique

A cap having a two-piece structure of a shell and a liner (so-called two-piece cap) generally has a structure as shown in FIG3 (see, for example, Patent Document 1). That is, the cap shown in FIG3 has a shell 1 and a liner 2 held in the shell 1 and sealing the container mouth M, and the liner 2 is provided with a middle leg 11 that is embedded in the container mouth M when the plug is closed.

Prior art literature

Patent Literature

Patent Document 1: Japanese Patent No. 5735744

Summary of the invention

Problems to be solved by the invention

In such a cap, it is important to strongly and closely fit the outer peripheral surface of the middle leg 11 to the inner peripheral surface of the container mouth M when the cap is closed, which is important in maintaining a high degree of airtightness of the container. Therefore, conventionally, the close fit of the outer peripheral surface of the middle leg 11 to the inner peripheral surface of the container mouth M is adjusted mainly by adjusting the amount of bulging of the outer peripheral surface of the middle leg 11 toward the outside. However, if the bulging amount is increased, although the above-mentioned close fit and thus the airtightness are improved, there is a problem that it also leads to an increase in the closing torque related to the defective situation such as poor capping, and an increase in the opening torque directly related to the reduction of usability.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a cap which can suppress increases in a plug-opening torque and a plug-closing torque and achieve improved airtightness.

Means for solving problems

In order to achieve the above-mentioned purpose, the cover of the present invention comprises: a shell having a top wall and a side wall hanging down from the periphery of the top wall, wherein an internal thread is formed on the side wall and screwed with the external thread of the container mouth; and a gasket, which is retained in the shell to seal the container mouth, wherein the gasket comprises: a top plate, which covers the container mouth; and a middle leg, which is connected to the lower surface of the top plate and tightly fits with the inner peripheral surface of the container mouth, and the cover is constructed so that when the plug is closed, the top plate pressed downward by the top wall is elastically deformed, and the central part of the top plate is displaced downward more than the peripheral part (Technical Solution 1).

In the above-mentioned cover, the lower surface of the top wall may be formed as a curved surface that is convex downward as a whole, and the upper surface of the top plate may be formed as a curved surface that is convex upward as a whole (technical solution 2).

In the above-mentioned cover, the gasket may also have a bending portion that bends downward from the periphery of the top plate and fits tightly with the outer peripheral surface of the container mouth, and a force-applying portion that protrudes toward the inner side of the shell is provided near the boundary between the top wall and the side wall of the shell, or a force-applying portion that protrudes toward the outer side is provided on the outer peripheral surface of the gasket (Technical Solution 3).

Effects of the Invention

In the present invention, it is possible to obtain a cap that can suppress increases in the plug-opening torque and the plug-closing torque and achieve improved airtightness.

That is, in the cap of the invention of each technical solution of the present application, when the plug is closed, as the center of the top plate of the gasket is elastically deformed to be displaced downward more than the peripheral portion, the middle leg is elastically deformed in a manner that the diameter of the lower end (open end) side is expanded, thereby the outer peripheral surface of the middle leg is tightly fitted to the inner peripheral surface of the container mouth, and the airtightness can be improved. In addition, it is not necessary to make the outer peripheral surface of the middle leg bulge outward particularly large as in the past, so that the increase of the plug closing torque and the plug opening torque can be suppressed, and it can also help to reduce them.

The cap of the invention according to claim 2 can realize reliable effects such as the improvement of the airtightness described above.

In a cap having a force-applying portion, usually, when closing the plug, during the process of the container mouth entering between the middle leg and the bent portion, the bent portion applied by the force-applying portion abuts against the outer peripheral side of the upper end of the container mouth, and may be difficult to close. However, in the cap of the invention of Technical Solution 3, when closing the plug, the lower end (front end) side of the bent portion elastically deforms in an expanded manner as the central portion of the top plate of the gasket is displaced downward more elastically than the peripheral portion, thereby enabling easy closing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing the structure of a cap and a container mouth portion to which the cap is attached according to an embodiment of the present invention.

FIG. 2(A) and FIG. 2(B) are half longitudinal sectional views showing the structures of the main parts of the housing and the gasket of the cover.

FIG. 3 is a semi-longitudinal sectional view showing the structure of the cover.

Detailed ways

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

As shown in Fig. 1 and Fig. 3, the cap of this example is mounted on the container mouth M, and has a housing 1 made of, for example, a polypropylene resin and molded by injection molding, and a liner 2 made of, for example, a polyethylene resin and molded by injection molding, etc. It should be noted that the container having the container mouth M is, for example, a PET bottle, which contains contents such as carbonated beverages and soft drinks.

As shown in FIGS. 1 and 3 , the housing 1 has a circular top wall 3 in plan view and a substantially cylindrical side wall 4 hanging from the periphery of the top wall 3 . An internal thread 5 screwed with an external thread M1 of the container mouth M is formed on the side wall 4 .

In addition, the cover of this example is a peeling cover, and an annular belt (anti-bite belt) 8 is connected to the lower side of the side wall 4 via multiple breakable bridge parts 7, and a locking piece (blocking piece) 9 is provided on the belt 8 to engage with the annular protrusion (convex part) M2 of the container mouth M.

On the other hand, the gasket 2 has a circular top plate 10 that covers the container mouth M in a closed state, a roughly cylindrical middle leg 11 that is concentrically connected to the lower surface of the top plate 10 and tightly fits with the inner circumference of the container mouth M, and a bent portion 12 that is bent downward from the periphery of the top plate 10 and tightly fits with the outer circumference of the container mouth M. The gasket 2 is configured to be able to seal the container mouth M (refer to Figure 3).

Moreover, the gasket 2 is retained in the shell 1 for use. Specifically, if the uppermost portion of the internal thread 5 of the shell 1 is used as the gasket anti-detachment portion, and the bent portion 12 of the gasket 2 is pressed between the gasket anti-detachment portion and the top wall 3, the gasket 2 is retained in the shell 1 in a state where it can perform relative movement in the direction of the central axis of the shell 1 and around the central axis.

In the cap of this structure, during the process of closing the plug, the locking piece 9 of the shell 1 passes over the annular protrusion M2, and in the closed state after the closing operation is completed, the locking piece 9 elastically returns to a posture that can be locked under the annular protrusion M2. In addition, in the closed state, the middle leg 11 of the gasket 2 is embedded in the opening of the container mouth M, and the part (connecting part) 13 between the middle leg 11 and the bent part 12 in the top plate 10 is in a state of being sandwiched by the upper end of the container mouth M and the top wall 3 of the shell 1.

Furthermore, in this example, in order to make the bent portion 12 fit firmly and tightly against the outer peripheral surface of the container mouth M in the closed state, an annular force-applying portion 14 (refer to FIG. 3 ) protruding toward the inner side of the shell 1 is provided near the boundary between the top wall 3 and the side wall 4 of the shell 1. In the closed state, the force-applying portion 14 applies downward force to the bent portion 12, and the force is reliably and efficiently converted into a force pressing the bent portion 12 against the outer peripheral surface of the container mouth M.

Moreover, in this example, as shown in FIG. 2 (A) and FIG. 2 (B), the lower surface of the top wall 3 of the shell 1 is formed as a "curved surface that is convex downward as a whole", and the upper surface of the top plate 10 of the gasket 2 is formed as a "curved surface that is convex upward as a whole", so that when the plug is closed, the top plate 10 of the gasket 2, the upper surface of which is pressed downward by the lower surface of the top wall 3 of the shell 1, is elastically deformed, and the central part of the top plate 10 is displaced downward more than the peripheral part. It should be noted that the "curved surface that is convex downward as a whole" and the "curved surface that is convex upward as a whole" respectively refer to areas that are allowed to partially exist without constituting a "curved surface that is convex downward" or a "curved surface that is convex upward", and as a specific example of an area that does not constitute a "curved surface that is convex downward" or a "curved surface that is convex upward", the concave portion 15 shown in FIG. 2 (B) and FIG. 3 can be cited.

In the cap of this example having such a structure, when the plug is closed, as the center portion of the top plate 10 of the gasket 2 is elastically deformed to be displaced downward more than the peripheral portion, the middle leg 11 is elastically deformed in such a way that the diameter of the lower end (open end) side thereof is expanded, thereby making the outer peripheral surface of the middle leg 11 strongly and closely fit the inner peripheral surface of the container mouth M, thereby achieving improved airtightness. Furthermore, it is not necessary to make the outer peripheral surface of the middle leg 11 bulge outward particularly much as in the past, so that the increase of the plug closing torque and the plug opening torque can be suppressed, and on the contrary, it can contribute to their reduction.

In addition, in the cap having the force-applying portion 14 as described above, usually, when the cap is closed, the bent portion 12 applied by the force-applying portion 14 abuts against the outer peripheral side of the upper end of the container mouth M during the process of the container mouth M entering between the middle leg 11 and the bent portion 12, and may be difficult to close. However, in this example, when the cap is closed, the lower end (front end) side of the bent portion 12 is elastically deformed in a manner of expanding the diameter along with the elastic deformation of the central portion of the top plate 10 of the gasket 2 that is displaced downward more than the peripheral portion, and thus it can be expected that the cap is easy to close. Of course, in the closed state, the bent portion 12 is in a state of strong and tight contact with the outer peripheral surface of the container mouth M due to the force applied by the force-applying portion 14.

The present invention is not limited to the above-described embodiment, and can be implemented with various modifications without departing from the gist of the present invention. For example, the following modifications can be given.

In the above-mentioned embodiment, as shown in Figure 2 (A) and Figure 2 (B), the lower surface of the top wall 3 of the shell 1 is formed as a "curved surface that bulges downward as a whole", and the upper surface of the top plate 10 of the gasket 2 is formed as a "curved surface that bulges upward as a whole". Thus, when the bolt is closed, the top plate 10 of the gasket 2, whose upper surface is pressed downward by the lower surface of the top wall 3 of the shell 1, is elastically deformed, and the central part of the top plate 10 is displaced downward more than the peripheral part. In short, when the bolt is closed, the top plate 10 of the gasket 2, whose upper surface is pressed downward by the lower surface of the top wall 3 of the shell 1, is elastically deformed, and the central part of the top plate 10 is displaced downward more than the peripheral part. The mechanism is not limited to the structures of Figure 2 (A) and Figure 2 (B).

For example, as shown in (B) of Figure 2, the upper surface of the top plate 10 of the gasket 2 can also be formed as a "curved surface that bulges upward as a whole". On the other hand, the lower surface of the top wall 3 of the shell 1 is formed to be flat (plane), and can also be formed as a "curved surface that bulges upward as a whole" that is smoother than the upper surface of the top plate 10 of the gasket 2.

Alternatively, as shown in (A) of Figure 2, the lower surface of the top wall 3 of the shell 1 can also be formed as a "curved surface that bulges downward as a whole". On the other hand, the upper surface of the top plate 10 of the pad 2 is formed to be flat (plane), and can also be formed as a "curved surface that bulges downward as a whole" that is smoother than the lower surface of the top wall 3 of the shell 1.

Alternatively, a protrusion protruding downward may be provided at the center of the lower surface of the top wall 3 of the housing 1, or a protrusion protruding upward may be provided at the center of the upper surface of the top plate 10 of the liner 2. In these cases, the size (height, lateral width), position, number, and shape of the protrusion may be appropriately determined within the following range: when the plug is closed, the top plate 10 of the liner 2, whose upper surface is pressed downward by the lower surface of the top wall 3 of the housing 1, is elastically deformed, and the center of the top plate 10 is displaced downward more than the peripheral portion.

Alternatively, the outer diameter and angle of the middle leg 11 may be adjusted so that when the middle leg 11 is inserted into the opening of the container mouth M, the central portion of the top plate 10 protrudes upward (outside the opening) more than the peripheral portion, and when the plug is closed, the lower surface of the top wall 3 is used to press the protruding central portion, so that the elastically deformed central portion of the top plate 10 is displaced downward more than the peripheral portion. In this case, the lower surface of the top wall 3 and the upper surface of the top plate 10 can be made flat (plane).

In addition, in the above-mentioned embodiment, a force-applying portion 14 protruding in a wedge shape toward the inner side of the housing 1 when viewed in longitudinal section is provided near the boundary between the top wall 3 and the side wall 4 in the housing 1, but the present invention is not limited thereto, and a force-applying portion 14 protruding toward the outer side may be provided on the outer peripheral surface of the gasket 2. In this case, it is considered that the force-applying portion 14 is removed from the housing 1, and the inner diameter thereof gradually increases toward the lower side near the boundary between the top wall 3 and the side wall 4.

Furthermore, it is of course possible to appropriately combine the above-mentioned modifications.

Description of symbols

1: Shell; 2: Gasket; 3: Top wall; 4: Side wall; 5: Internal thread; 7: Bridge piece; 8: Belt; 9: Locking piece; 10: Top plate; 11: Middle leg; 12: Bending part; 13: Connecting part; 14: Force-applying part; 15: Recessed part; M: Container mouth; M1: External thread; M2: Annular protrusion.

Claims (3)

1. A lid, having:

A housing having a top wall and a side wall depending from a periphery of the top wall, the side wall being formed with an internal thread for threaded engagement with an external thread of the container finish; and

A gasket which is held in the housing and seals the mouth of the container,

Wherein,

The gasket has:

A top plate covering the container mouth; and

A middle leg connected with the lower surface of the top plate and closely attached to the inner peripheral surface of the container mouth,

The lid is configured such that, when closing the closure, the top plate pressed downward by the top wall is elastically deformed, the central portion of the top plate is displaced downward more than the peripheral portion, the middle leg is elastically deformed so as to expand its open end side, and the contact area between the upper surface of the top plate and the lower surface of the top wall when closing the closure is completed is larger than the contact area between the upper surface of the top plate and the lower surface of the top wall when closing the closure is started, whereby the outer peripheral surface of the middle leg and the inner peripheral surface of the container mouth are strongly adhered to each other, and an improvement in air tightness can be achieved.

2. The cap of claim 1, wherein,

The lower surface of the top wall is formed as a curved surface that is convex downward as a whole, and the upper surface of the top plate is formed as a curved surface that is convex upward as a whole.

3. The cap of claim 1 or 2, wherein,

The liner has a bending part which is bent downwards from the periphery of the top plate and is closely attached to the outer peripheral surface of the container mouth part,

An urging portion protruding toward the inside of the case is provided near the boundary between the top wall and the side wall of the case, or an urging portion protruding toward the outside is provided on the outer peripheral surface of the pad.