JP2020083388A - Synthetic resin cap - Google Patents

Abstract

To provide a synthetic resin cap capable of achieving certainty of whitening and breakage prevention of a tamper-evident band while achieving prevention of occurrence of slipping-out.SOLUTION: A synthetic resin cap has a nearly cylindrical lateral wall 14 including a skirt wall 3 provided with a female screw 5 screwed with a male screw formed in the outer periphery of a container mouth, and a band (tamper-evident band) 9 which is connected to the lower part of the skirt wall via an annular weakened part 10, and in which a plurality of engaging parts 11 engaged with engaged parts formed in the outer periphery of the container mouth are provided at intervals in the circumferential direction. In the inner peripheral surface of the band, fitting parts 12 protruding inward from the upper end part inner surface of the band are provided in the whole circumference above the engaging parts. The fitting part is constituted of a direct upper part 12A positioned just above the engaging part, and a connection part 12B for connecting the direct upper parts adjacent in the circumferential direction of the band. The connection part protrudes inward from the upper end part inner surface of the band, and has an inward-protruding quantity to the band smaller than that of the direct upper part.SELECTED DRAWING: Figure 2

Description

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

BACKGROUND ART A cap that is attached to the mouth of a container that stores contents such as beverages and that can be checked at a glance whether or not the container has been opened is widely known. For example, as shown in FIGS. 4(A) and 4(B), the cap disclosed in Patent Document 1 has a cap body 53 having a skirt wall 52 provided with a female screw 51 that is screwed into the male screw M1 of the container opening M. And a tamper evidence band 55 connected to the lower part of the skirt wall 52 via an annular weakening portion 54.

In the above cap, the engaging portion (hook) 56 provided on the inner circumference of the tamper evidence band 55 is attached to the container mouth portion M when the opening operation (first opening operation) from the state where the container mouth portion M is attached is performed. After being locked to an annular protrusion (an example of an engaged portion) M2 provided on the outer periphery of the tamper evidence band 55 and the skirt wall 52, the annular weakened portion 54 is broken, and the cap body 53 and the tamper evidence band are separated. 55 and 55 are separated from each other. Therefore, it is possible to easily confirm whether or not the opening operation is performed by visually observing whether or not the bridge (bridge portion) formed between the perforated slits forming the annular weakening portion 54 is broken. it can.

Patent No. 5291175

By the way, in the conventional synthetic resin cap described above, the fitting portion 57 protruding inward from the inner surface of the upper end portion of the tamper evidence band 55 is provided above the engaging portion 56 on the inner peripheral surface of the tamper evidence band 55. The fitting portion 57 is provided so as to be continuous in the circumferential direction of the band 55, and is configured to be fitted to the outer peripheral surface of the engaged portion M2 of the container mouth portion M. Accordingly, when the stopper is opened, the fitting portion 57 fits on the outer peripheral surface of the annular protrusion M2 of the container mouth portion M, and the engaging portion 56 surely engages with the annular protrusion M2. It is possible to prevent occurrence of so-called slip-out, in which the engaging portion 56 rides over the annular protrusion M2 without breaking.

However, in the above-described conventional synthetic resin cap, if the contact (fitting) between the fitting portion 57 and the annular protrusion M2 of the container mouth portion M is too strong, the tamper evidence band 55 may be whitened or cracked. ..

The present invention has been made in consideration of the above-mentioned matters, and an object thereof is a synthetic resin which can ensure prevention of whitening and cracking of a tamper evidence band while preventing the occurrence of a slip-off. To provide a cap.

In order to achieve the above object, the synthetic resin cap according to the present invention has a substantially cylindrical side wall, and the side wall is provided with a female screw that is screwed into a male screw formed on the outer periphery of the container mouth. A skirt wall and a plurality of engaging portions, which are connected to a lower portion of the skirt wall via an annular weakening portion and engage with an engaged portion formed on the outer periphery of the container mouth, are provided at intervals in the circumferential direction. A tamper-evidence band formed on the inner peripheral surface of the tamper-evidence band, the fitting portion protruding inward from the inner surface of the upper end portion of the tamper-evidence band over the entire circumference of the engaging portion. The fitting part is provided, and the fitting part is composed of a part directly above the engaging part and a connecting part connecting the parts directly adjacent to each other in the circumferential direction of the tamper evidence band. The tamper-evidence band protrudes inward from the inner surface of the upper end of the tamper-evidence band, and has a smaller amount of inward projection than the upper part.

According to the invention of the present application, a synthetic resin cap is obtained which can prevent whitening and cracking of the tamper evidence band while ensuring prevention of the occurrence of a slip-out.

That is, if the fitting portion 57 has a uniform wall thickness in the circumferential direction like the conventional synthetic resin cap shown in FIGS. 4(A) and 4(B), the fitting portion 57 and the container mouth M If the contact (fitting) with the annular protrusion M2 is too strong, the tamper evidence band 55 is more likely to be whitened or cracked. However, in the cap of the present invention, since the fitting portion is constituted by the upper portion and the connecting portion which have different protrusion amounts inward of the tamper evidence band, the fitting portion (immediate upper portion) and the annular protrusion of the container mouth portion M are formed. Even if the contact (fitting) with M2 is too strong, the fitting is alleviated by the connecting portion, so that it is possible to ensure the prevention of whitening and cracking of the tamper evidence band.

It is a bottom view which shows roughly the structure of the synthetic resin cap which concerns on one embodiment of this invention. 1A is a sectional view taken along line AA in FIG. 1, FIG. 1B is an enlarged view of a portion B in FIG. 1, and FIG. 3C is a sectional view taken along line DD in FIG. It is CC sectional view taken on the line in FIG. (A) is a conventional synthetic resin cap, (B) is a front view showing the state of mounting to the container mouth.

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 FIGS. 1 and 2A is a container port having a male screw M1 and an annular projection (an example of an engaged portion) M2 as shown in FIG. 4B. It is used by being attached to the portion M (for example, the mouth portion of a container such as a PET bottle), and is integrally formed of polyethylene by compression molding or injection molding. The material forming the cap 1 is not particularly limited, and polypropylene and the like are preferably used in addition to polyethylene used in the present embodiment.

The cap 1 has a substantially circular top wall 2 in a plan view and a substantially cylindrical skirt wall 3 extending downward from the outer peripheral portion of the top wall 2 (see FIGS. 1 and 2A). Here, as shown in FIG. 2A, 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 thereof. The female screw 5 is formed on the outer periphery of the container mouth M. It is possible to connect to the external thread M1 that is formed.

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, the inner surface (lower surface) of the top wall 2 shown in FIG. The annular middle foot (inner ring) 6, the annular rib 7 and the annular outer foot (outer ring) 8 which are continuously connected to each other closely contact the container mouth M, whereby the container mouth M is sealed. Become. That is, in the state where 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 attached to the container mouth M. The outer leg 8 is configured to be in close contact with the annular upper end surface and the outer peripheral surface 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 (not opened at all times), 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 separates from the container opening M, but the tamper evidence connected to the lower part of the skirt wall 3 A band (hereinafter, simply referred to as “band”) 9 (see FIG. 2A) is configured to remain in the container opening M.

That is, the band 9 is connected to the lower portion of the skirt wall 3 via the annular weakening portion 10 extending over the entire circumference of the skirt wall 3 (see FIG. 2A). And a band 9 are vertically defined so that the skirt wall 3 and the band 9 are intermittently extended (perforated) in the circumferential direction of the band 9 and a bridge existing between adjacent slits. Breaks when pulled with a predetermined force.

Here, in this example, the outer diameter of the band 9 is made uniform in the vertical direction, while the band 9 is configured so as to project inward on the inner peripheral side and the amount of inward projection increases toward the upper side. Five hooks (an example of engaging portions) 11 are provided at intervals (equal intervals in this example) in the circumferential direction (an example of a plurality of hooks) 11 (see FIGS. 1 and 2A). Each hook 11 is substantially below an annular protrusion M2 (see FIG. 4B) formed below the male screw M1 on the outer periphery of the container mouth M in a state where the cap 1 is attached to the container mouth M. And is locked to the annular protrusion M2 by the opening operation. That is, the hook 11 is configured to be capable of being locked to the annular protrusion M2 from below. The chain double-dashed line in FIG. 3 shows the cross-sectional shape of the portion where the hook 11 is not provided.

Further, as shown in FIG. 3, on the inner peripheral side of the band 9, above the hook 11, it projects inward from the inner surface of the upper end of the band 9, and the maximum projection amount thereof is larger than the maximum projection amount of the hook 11. A small fitting portion 12 (having an inner diameter larger than the inner diameter of the hook 11) is provided over the entire circumference of the band 9, and an inclined portion 13 having a larger inner diameter toward the upper side is provided above the fitting portion 12.

Thus, in a state in which the annular protrusion M2 is attached to the container opening M and is not opened, the annular protrusion M2 is positioned inside or above the inclined portion 13, and when the cap 1 is rotated in the opening direction from this state, the container opening M2 is opened. The cap 1 is relatively raised with respect to M, the fitting portion 12 is fitted into the annular protrusion M2, and the hook 11 is locked to the annular protrusion M2 from below. When the cap 1 is further rotated in the unsealing direction, the annular weakening portion 10 eventually breaks 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 above the container body It will be detached from the mouth M.

Therefore, the inclined portion 13 contacts the annular protrusion M2 and the fitting portion 12 fits on the outer peripheral surface of the annular protrusion M2 until the hook 11 is locked to the annular protrusion M2 from below. As a result, the band 9 is prevented from being lifted up obliquely, and the annular weakened portion 10 is substantially evenly broken without being biased, so that the tamper evidence is improved. When the stopper is opened, the fitting portion 12 fits on the outer peripheral surface of the annular protrusion M2 of the container mouth portion M, and the hook 11 surely engages the annular protrusion M2, so that the annular weakening portion 10 is broken. Without the hook 11, it is possible to prevent occurrence of so-called slip-out, in which the hook 11 gets over the annular protrusion M2.

By the way, when the fitting portion 12 is provided as described above, when the cap 1 is attached to the container mouth portion M, the resistance generated between the both 1 and M becomes large, and the annular weakened portion 10 is more likely to be broken. Therefore, in this example, in order to enhance the function of preventing the annular weakened portion 10 from breaking when the cap 1 is attached to the container mouth portion M, the substantially cylindrical side wall 14 including the skirt wall 3 and the band 9 (see FIG. A groove 15 continuous in the circumferential direction of the side wall 14 is provided in a region between the annular weakened portion 10 and the lowermost position of the internal thread 5 on the inner peripheral surface (see A)) to deform (expand) the side wall 14. Made easier

Specifically, as shown in FIG. 3, the groove 15 is formed in a taper shape so as to become deeper from the upper end toward the lower end. Further, in the present example, the outer peripheral surface of the side wall 14 is located above the annular weakened portion 10 and apart from the lowermost position of the internal thread 5 to the lower side (in the illustrated example, the annular weakened portion 10 is located below the lowermost position of the internal thread 5). A thick annular protrusion 16 is provided at a position close to the groove 15. The groove 15 extends above the annular protrusion 16, and the lower end of the groove 15 is continuous with the inclined portion 13 below the annular weakening portion 10. is doing.

By providing the groove 15 as described above, the portion of the side wall 14 above the annular weakened portion 10 (in this example, the portion from the lower portion of the skirt wall 3 to the upper portion of the band 9) is thinned and deformed (diameter expansion). ) Is facilitated and at least a part of the force applied from the container mouth portion M to the annular weakening portion 10 when the cap 1 is attached to the container mouth portion M is converted into the deformation, so that the fracture preventing function of the annular weakening portion 10 is improved. In addition, the amount of resin used can be reduced as the side wall 14 becomes thinner.

In particular, in this example, as described above, the groove 15 is extended to above the thick annular protruding portion 16, so that a thin portion that is easily deformed to a portion above the annular protruding portion 16 on the side wall 14 is inevitable. Since it is formed, the above-mentioned fracture prevention function is surely enhanced. Then, from the viewpoint of more reliably obtaining such an effect, it is preferable that the upper end of the groove 15 is closer to the lowermost position of the female screw 5 than the annular weakening portion 10, and in this case, the side wall 14 ( Since the diameter of the band 9) is increased, it is possible to make the annular weakened portion 10 less likely to break. On the other hand, the lower end of the groove 15 does not need to extend below the annular weakening portion 10, and may extend to the height position of the lower end of the annular protrusion 16, for example.

In this example, as shown in FIGS. 2(B), (C) and FIG. 3, the fitting portion 12 provided over the entire circumference of the band 9 is provided with the immediately upper portion 12A located above each hook 11, The band 9 is formed by a connecting portion 12B that connects the immediately upper portions 12A adjacent to each other in the circumferential direction of the band 9. The connecting portion 12B projects inward from the inner surface of the upper end portion of the band 9 and is higher than the band 9A from the upper portion 12A. The amount of inward projection of is reduced by, for example, about 0.1 mm to 0.3 mm. For example, in the band 9, when the thickness of the portion corresponding to the upper portion 12A is 0.75 mm and the thickness of the portion corresponding to the connecting portion 12B is 0.6 mm, the outer diameters of both portions are the same, This means that the amount of protrusion of the portion 12B inward of the band 9 is 0.15 mm smaller than that of the portion 12A immediately above, and the thickness of the portion of the band 9 corresponding to the connecting portion 12B (that is, the circumferential direction of the band 9 in the circumferential direction). Is preferably 0.5 mm or more.

Here, as in the conventional synthetic resin cap shown in FIGS. 4(A) and 4(B), the fitting portion 12 has a uniform wall thickness in the circumferential direction, and the connecting portion 12B is located just above the upper portion 12A. When the inner surface is flush with the inner surface, the band 9 is more likely to be whitened or cracked when the fitting portion 12 and the annular protrusion M2 of the container mouth M are abutted (fitted) to each other too strongly. However, in the cap 1 of this example, since the fitting portion 12 is configured by the upper portion 12A and the connecting portion 12B having different amounts of inward protrusion of the band 9, the fitting portion 12 and the annular protrusion of the container mouth portion M are formed. Even if the contact (fitting) with M2 is too strong, the fitting is relaxed by the connecting portion 12B, so that the whitening and cracking of the band 9 can be reliably prevented.

On the contrary, if the connecting portion 12B is flush with the inner surface of the upper end of the band 9 and the fitting portion 12 is composed of only the upper portion 12A, the pressure applied to the band 9 at the time of demolding etc. The band 9 is likely to be whitened or cracked by being concentrated near the edge. However, in the cap 1 of this example, since the connecting portion 12B is projected more inwardly of the band 9 than the inner surface of the upper end of the band 9, the concentration of the above pressure is suppressed, and the band 9 is whitened at the time of demolding or the like. It is also possible to ensure the prevention of cracks.

Further, by providing a difference in the amount of protrusion of the upper portion 12A and the connecting portion 12B inwardly of the band 9, the cleaning liquid for the container mouth portion M is set to the inner space of the connecting portion 12B (the gap between the connecting portion 12B and the annular protrusion M2). It can also be used as a drainage port.

It should be noted that the present invention is not limited to the above-described embodiments at all, 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 can be mentioned.

In the example of FIGS. 2(A) to 2(C), the upper portion 12A is provided in a region just above the hook 11, but the present invention is not limited to this, and the upper portion 12A extends laterally from the region directly above the hook 11. It may be slightly protruding, or conversely, the connecting portion 12B may be slightly overlapped with the region immediately above the hook 11. Further, in the example of FIG. 2C, the vertical width of the connecting portion 12B is the same as the vertical width of the direct upper portion 12A, but the present invention is not limited to this, and the vertical width of the connecting portion 12B is higher than the vertical width of the direct upper portion 12A. May be smaller. However, it is preferable that the vertical width of the connecting portion 12B is equal to or more than half of the vertical width of the immediately upper portion 12A in order to prevent stress concentration near the connecting portion 12B during demolding or opening.

In the example of FIG. 3, the groove 15 has a taper shape that becomes deeper toward the lower side, but the shape of the groove 15 is not limited to this. For example, the groove 15 may have a deeper taper shape toward the upper side or a constant depth vertically. The depth of the groove 15 may be changed regularly or irregularly in the vertical direction.

Further, although the groove 15 is continuous in the circumferential direction of the side wall in the example of FIG. 3, the present invention is not limited to this, and the groove 15 may be interrupted in the circumferential direction of the side wall 14. In this case, various configurations such as the number and width of the grooves 15 can be set within a range in which the side wall 14 can be easily deformed (diameter expansion) and the fracture preventing function of the annular weakened portion 10 can be enhanced.

A plurality of grooves 15 may be provided in the vertical direction. In particular, when the grooves 15 are intermittently provided in the circumferential direction of the side wall 14, the plurality of grooves 15 are arranged in a matrix or a staggered pattern along the circumferential direction of the inner peripheral surface of the side wall 14. It may be provided in.

It goes without saying that the above modified examples may be appropriately combined.

1 Cap 2 Top Wall 3 Skirt Wall 4 Knurled Groove 5 Female Screw 6 Middle Foot 7 Annular Rib 8 Outer Feet 9 Tamper Evidence Band 10 Annular Weakened Section 11 Hook (engagement section)
12 Fitting part 12A Direct upper part 12B Connecting part 13 Sloping part 14 Side wall 15 Groove 16 Annular protrusion 51 Female screw 52 Skirt wall 53 Cap body 54 Annular weakening part 55 Tamper evidence band 56 Engaging part 57 Fitting part M Container mouth part M1 Male screw M2 Annular protrusion (engaged part)

Claims (1)

It has a substantially cylindrical side wall,
The side wall is connected to a skirt wall provided with a female screw that is screwed with a male screw formed on the outer periphery of the container mouth, and is connected to the lower portion of the skirt wall via an annular weakening portion, and is formed on the outer periphery of the container mouth. An engaging portion that engages with the engaged portion, including a plurality of tamper evidence bands provided at intervals in the circumferential direction,
On the inner peripheral surface of the tamper evidence band, above the engaging portion, a fitting portion that projects inward from the inner surface of the upper end portion of the tamper evidence band is provided all around.
The fitting portion is configured by a portion directly above the engaging portion and a connecting portion that connects the upper portions adjacent to each other in the circumferential direction of the tamper evidence band, and the connecting portion is the tamper. A cap made of synthetic resin, which protrudes inward from an inner surface of an upper end portion of the evidence band, and has a smaller amount of inward projection of the tamper evidence band than the upper portion.