JP2002068233A - Plastic cap - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plastic cap which prevents an internal pressure of the cap from increasing so that there is no fear that the cap accidentally removes from a bottle mouth. SOLUTION: The cap for a bottle having a flange 23 on an external surface of the mouth 11 includes a top wall 31 whose periphery is mounted on an upper end surface of the mouth 11 and a peripheral wall 33 hangingly connected with a periphery of the top wall 31 and put over an external surface of the flange 23. An inward annular engaging protrusion 48 to be engaged with the flange 23 from downward is provided at a lower end of an internal surface of the peripheral wall 33. The engaging protrusion 48 extends continuously along the entire periphery 33. The protrusion 48 includes a deaerating groove 49 for preventing an internal pressure of the cap from increasing as the cap is pressed down when the protrusion 48 is to be engaged with the flange 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic cap used for sealing a mouth of a milk bottle, for example.

[0002]

2. Description of the Related Art A plastic cap of this type is a bottle cap having a flange on an outer surface of a mouth, and has a top wall on which an edge is placed on an upper end surface of the mouth, and a drooping shape on the periphery of the top wall. And a peripheral wall that is coated on the outer surface of the flange portion, and at the lower end of the peripheral wall, an inward annular engagement ridge that is engaged with the flange portion from below is provided.
It is known that it extends continuously over the entire peripheral wall.

[0003]

In the above-mentioned plastic cap, when the engaging ridge is engaged with the flange,
As the cap is pressed down, the internal pressure of the cap may increase. If the cap is put on the bottle mouth while keeping this as it is, the internal pressure of the cap further rises due to temperature rise, etc., and this internal pressure acts to push up the cap, so the engaging ridge runs on the flange. In some cases, the cap came off the mouth of the bottle.

An object of the present invention is to provide a plastic cap which prevents an increase in the internal pressure of the cap and which does not have to be inadvertently detached from the mouth of the bottle.

[0005]

A plastic cap according to the present invention is a cap for a bottle having a flange on the outer surface of a mouth. The top wall has a peripheral portion mounted on the upper end surface of the mouth, and the peripheral portion of the top wall. And a peripheral wall that covers the outer surface of the flange portion and is provided with an inward annular engaging ridge that is engaged with the flange portion from below at the lower end of the inner surface of the peripheral wall. In a plastic cap in which the ridge extends continuously over the entire circumference of the peripheral wall, when the engagement ridge is engaged with the flange, the plastic cap is provided with air bleeding means for preventing an increase in the internal pressure of the cap due to the cap pressing down. It is assumed that.

In the plastic cap according to the present invention, even if the internal pressure of the cap is going to rise, the air venting means prevents this. Therefore, there is no fear that the cap is accidentally detached from the bottle mouth based on the rise in the cap internal pressure.

Further, when the air bleeding means comprises an air bleed groove provided so as to communicate the upper and lower portions of the engaging ridge, the air bleeding means can be constituted with a simple structure.

A knob is provided outward at the lower end of the outer peripheral surface of the peripheral wall, and the air bleeding means is provided with a plurality of engaging ridges at a plurality of portions in the circumferential direction which equally divide the engaging ridges including the inner portion of the knob. It consists of a plurality of air vent grooves provided so that the upper and lower sides of the knob communicate with each other. If there are multiple air vent grooves in the inner part of the knob and one air vent groove in the other part, the knob Due to the presence of, the engaging ridge is locally reinforced only at that portion, but the reinforcement of the engaging ridge by the pick is weakened by the plurality of air vent grooves present at the portion inside the knob, The engaging ridge is maintained at a constant strength over substantially the entire circumference. Therefore, the engaging ridge can be easily engaged with and disengaged from the flange, and the resistance of the engaging ridge to an increase in internal pressure can be stably exhibited. Furthermore, the flange outer surface has an outwardly smooth surface formed smoothly over the entire circumference, and the inner peripheral surface is
It has an inward smooth surface that is brought into close contact with the entire outward smooth surface, and if the bottom surface of the air vent groove is flush with the inward smooth surface, the engaging ridge is completely engaged with the flange. Until the engagement, the air vent groove performs its function, so it is possible to ensure the necessary air release, and after the engaging ridge is completely engaged with the flange, it is smooth outward. Since the surface and the inward smooth surface are brought into close contact with each other, ventilation between the inside and outside of the cap by the air vent groove is shut off, so that there is no fear that foreign substances such as bacteria enter the cap through the air vent groove. Moreover, since the gap between the mouth and the cap is kept to a minimum, the rise in the internal pressure of the cap due to the rise in temperature is suppressed to a minimum.

Further, the air venting means may be an air vent hole provided so as to communicate the inside and outside of the peripheral wall above the engaging ridge, instead of the air vent groove.

Further, the outer surface of the flange portion has an outwardly smooth surface formed smoothly over the entire periphery thereof, and the inner surface of the peripheral wall includes the periphery of the air vent hole and is brought into close contact with the outwardly smooth surface over the entire surface. It may have an inward smooth surface.

[0011]

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

Referring to FIG. 1, there is shown a well-known mouth 200 of a glass milk bottle having a capacity of 200 ml, and a cap 12 made of a monolithic polyethylene molded article which is fitted over the mouth.

As shown in detail in FIG. 2, an enlarged diameter portion 21 is formed at the upper end of the bottle mouth portion 11, and as a result, a shoulder is formed on the inner surface of the bottle mouth portion 11 with a step lower than the upper end surface of the bottle mouth portion 11. A portion 22 is formed, and a flange portion 23 is formed on the outer surface of the bottle mouth portion 11 so as to correspond to the shoulder portion 22 in order to keep the thickness of the entire bottle constant. The flange portion 23 has a cylindrical outward smooth surface 23a that extends smoothly over the entire circumference.

The shoulder 22 may be used to receive a peripheral portion of a disc-shaped paper lid (not shown) which is well known as a sealing device according to another embodiment of the present invention. Below the flange 23 on the outer surface of the mouth 11, a reinforcing rib 24 having a substantially semicircular cross section is provided.

An annular recess 25 is formed in the middle of the height of the inner surface of the enlarged diameter portion 21.
Are formed. The concave portion 25 is formed by sinking during cooling of the glass material when the bottle is formed, and has a substantially arc-shaped cross-sectional profile, but is extremely fine such that it cannot be visually recognized.

The cap 12 has a top wall 31 having a peripheral portion mounted on the upper end surface of the bottle mouth portion 11, and a concentrically provided hanging vertically on the peripheral portion of the top wall 31 and sandwiching the bottle mouth portion 11 from inside and outside. Inner and outer wall 3
It consists of 2, 33.

The top wall 31 is a flat disk having a substantially uniform thickness. At the center of the lower surface of the top wall 31, there is provided a spherical downward projection 41 forming a gate when the cap 12 is formed. Inner and outer peripheral walls 3 on the lower surface of the top wall 31
An annular seal rib 42 is provided between 2 and 33. Rib 42
Has a triangular cross section, and its tip is brought into contact with the upper end surface of the bottle opening 11.

The height of the inner peripheral wall 32 is substantially half the height of the outer peripheral wall 33. At the lower end of the outer surface of the inner peripheral wall 32, an outwardly facing annular inner engaging ridge 43 is provided. The inner engaging ridge 43 has a triangular cross section, and its tip is in contact with the bottom of the recess 25.

A plurality of substantially vertical rectangular depressions are formed on the outer surface of the outer peripheral wall 33.
44 are formed at intervals in the circumferential direction of the outer peripheral wall 33. The lower end of the depression 44 is not open, and a smooth ring-shaped portion 45 having a constant thickness is left at the lower end of the outer peripheral wall 33.
An elongated annular knob 46 is provided so as to be continuous with a part of the ring-shaped portion 45. Three vertical ribs 47 are provided on the upper surface of the knob 46 and the outer surface of the outer peripheral wall 33 adjacent thereto.

At the lower end of the inner surface of the outer peripheral wall 33, an inward annular outer engaging ridge 48 having a substantially triangular cross section engaged with the flange 23 from below.
Is provided. Outer engaging ridge 48 on the inner surface of outer peripheral wall 33
The upper part is a cylindrical inward smooth surface 33a that extends smoothly over the entire circumference of the outer peripheral wall 33, and is closely in contact with the outward smooth surface 23a.

The outer engaging ridge 48 is formed with an air vent groove 49 penetrating vertically. The depth of the air vent groove 49 is equal to the height of the outer engaging ridge 48, and the bottom surface 49a of the air vent groove 49 is flush with the inward smooth surface 33a above it.

As shown in FIG. 3, the number of air vent grooves 49 is five in total, and the five air vent grooves 49 are dispersed in four parts. One of them is an inner portion of the knob 46, and this portion is the four portions that divide the outer engaging ridge 48 into four equal parts in the circumferential direction. There are two air vent grooves 49 only in one part inside the knob 46, and one air vent groove 49 in the other three parts.

The greater the number of air vent grooves 49, the more
Although the function of air release is performed, the presence of the air release groove 49 reduces the strength of the outer engagement ridge 48. Therefore,
If the number of air vent grooves 49 is too large, the strength of the outer engaging ridges 48 will be insufficient, and it will be impossible to prevent the cap from coming off due to an increase in internal pressure as described in the section of the prior art at the beginning.

The strength of the outer engaging ridge 48 is preferably constant over the entire circumference. Otherwise, Tsubabe
It becomes difficult to stably engage and disengage the outer engaging ridges 48 with respect to 23, and the detachment of the cap due to an increase in the internal pressure is more likely to occur from the weak portion of the outer engaging ridges 48 as a starting point. . In the above, only the part inside the knob 46 is 2
The presence of the two air vent grooves 49 is effective in weakening the reinforcement of the outer engagement ridge 48 by the knob 46.

When the cap 12 is put on the bottle mouth 11, FIG.
As shown in (a), when the cap 12 is placed on the bottle mouth 11 and pressed down, the inner peripheral wall 32 is compressed inward and the outer peripheral wall 33 is pushed outward, Joint ridge 48 is collar
You will be over 23. Initially, the outer engaging ridge 48 rides on the flange 23, and in this case, the outer engaging ridge 48
The distal end of the cap 48 is brought into contact, but in this state, the inside and outside of the cap 12 are communicated through the air vent groove 49. Therefore, by pressing down the cap 12, the cap
Even if the pressure inside the cap 12 rises, the pressure is released through the air vent groove 49, so that the pressure inside the cap 12 is prevented from rising. The function of the air vent groove 49 is maintained until the outer engaging ridge 48 gets over the flange 23 and the outer engaging ridge 48 is completely engaged with the flange 23 from below.

Eventually, as shown in FIG.
8 is completely engaged with the flange 23 from below, the flange 23
The base of the outer engagement ridge 48 is brought into contact with the lower surface. In this state, ventilation between the inside and outside of the cap 12 through the air vent groove 49 is blocked by the outer engagement ridge 48. Further, since the outward smooth surface 23a and the inward smooth surface 33a are brought into close contact with each other, there is no fear that germs or the like flow from between the bottle mouth 11 and the cap 12. Further, since the gap between the outer surface of the flange portion 23 and the outer peripheral wall 33 of the cap is extremely small, an increase in the internal pressure of the cap 12 due to an increase in temperature or the like is very small.

As described above, when the bottle is sealed, the inner peripheral wall 32 is fitted into the inner surface of the bottle mouth 11 and the inner engaging ridge 43 is engaged with the concave portion 25. However, the recess 25 and the inner engaging ridge 43 fit exactly as if they snap. Thereby, in addition to the cap 12 being held in the bottle mouth portion 11 in a stable posture, it greatly contributes to the improvement of the sealing property.

FIG. 4 shows a modification of the air venting means. In this modification, an air vent hole 51 is employed instead of the air vent groove 49. Air vent hole 51
Is penetrated by the outer peripheral wall 33 in and out of the middle of its height. The diameter of the air vent hole 51 is about 1 mm. Although the illustration of the air vent hole 51 is shown at one place, the air vent hole 51 may be provided at a plurality of positions equally dividing the outer peripheral wall 33. Further, a portion of the inner surface of the outer peripheral wall 33 including the periphery of the air vent hole 51 and above the outer engaging ridge 48 is formed as a smooth surface 33a, and is brought into close contact with the flange smooth surface 23a. As with the air vent groove 49, the air vent hole 51 has a flange 48
Until the vehicle passes over 23, it functions to communicate between the inside and outside of the cap 12. When the outer engaging ridge 48 gets over the flange 23, the outer engaging ridge 48 is engaged with the flange 23 to perform a sealing function, and at the same time, both the smooth surfaces 23a,
By bringing the 33a into close contact, the inner end opening of the air vent hole 51 is closed by the outward smooth surface 23a, and even if various bacteria or the like enter through the air vent hole 51, the diffusion can be avoided.

[0029]

According to the present invention, there is provided a plastic cap which prevents an increase in the internal pressure of the cap and does not have to be inadvertently detached from the bottle mouth.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a plastic cap according to the present invention together with a bottle mouth.

FIG. 2 is an enlarged vertical vertical sectional view of a main part of a portion shown in FIG.

FIG. 3 is a bottom view of the cap.

FIG. 4 is a longitudinal sectional view showing another embodiment and corresponding to FIG. 2;

[Explanation of symbols]

 11 Bottle mouth 12 Cap 31 Cap top wall 33 Cap outer peripheral wall 48 Engagement ridge 49 Air vent groove 51 Air vent hole

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshiro Watanabe 1 No. 10 Nishikawa, Taro Yasu, Kitajima-cho, Itano-gun, Tokushima Prefecture Inside Shikoku Kakoki Co., Ltd. Taro Yasushi character No. 10 Nishikawa 1 Shikoku Kakoki Co., Ltd. F term (reference) 3E084 AA04 AA12 AB01 CA01 CC03 DA01 DB09 DB13 DC03 EA04 EC03 FA01 FA09 GA08 GB12 GB17 HA03 HB01 HD01 HD04

Claims (6)

[Claims] 1. A cap for a bottle having a flange on an outer surface of a mouth, wherein a top wall on which a peripheral portion is placed on an upper end surface of the mouth, and which extends downwardly from the peripheral edge of the top wall and covers the outer surface of the flange. And an inward annular engaging ridge engaged with the flange from below is provided at the lower end of the inner surface of the peripheral wall, and the engaging ridge is continuously formed over the entire circumference of the peripheral wall. What is claimed is: 1. A plastic cap, comprising: a plastic cap provided with air bleeding means for preventing an internal pressure of the cap from rising when the engaging ridge is engaged with the flange. 2. The plastic cap according to claim 1, wherein the air bleeding means comprises an air bleed groove provided to communicate the upper and lower portions of the engaging ridge. 3. A knob is provided outward at a lower end of the outer peripheral surface of the peripheral wall, and the air bleeding means is provided with a plurality of engaging ridges at a plurality of circumferentially equally dividing engaging ridges including an inner portion of the knob. A plurality of air vent grooves provided so as to communicate the upper and lower sides of the knob, a plurality of air vent grooves are present in a portion inside the knob, and one air vent groove is present in the other portion. 2. The plastic cap according to 1. 4. The outer surface of the flange portion has an outwardly smooth surface formed smoothly over the entire circumference thereof, and the inner surface of the peripheral wall has an inwardly smooth surface which is brought into close contact with the entire outwardly smooth surface. 4. The plastic cap according to claim 2, wherein a bottom surface of the air vent groove is flush with an inward smooth surface. 5. 5. The plastic cap according to claim 1, wherein the air bleeding means comprises an air bleed hole provided to communicate between the inside and outside of the peripheral wall above the engaging ridge. 6. The outer surface of the flange portion has an outwardly smooth surface formed smoothly over the entire circumference thereof, and the inner surface of the peripheral wall includes the periphery of the air vent hole and is brought into close contact with the outwardly smooth surface over the entire surface. The plastic cap according to claim 5, which has an inward smooth surface.