JP2015101360A - Synthetic resin container lid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a synthetic resin container lid capable of surely avoiding incidental breakage of a breakage line (18) when a container lid (2) is attached to a neck (38) of the container, and avoiding separation of the container lid from the neck without breakage of the breakage line when the neck of the container is opened.SOLUTION: A thin part (36) extending in an axial direction between engagement projections (34) is formed on a tamper-evident skirt part (22).

Description

  The present invention relates to a synthetic resin container lid having tamper-evident characteristics, more specifically, a circular top wall and a cylindrical skirt wall depending from the periphery of the top wall. The skirt wall is partitioned into a main part above the breaking line and a tamper evidence hem below the breaking line, and a female screw is formed on the inner peripheral surface of the main part of the skirt wall. The present invention relates to a synthetic resin container lid in which strips are formed and a plurality of locking projections are formed at intervals in the circumferential direction on the inner circumferential surface of the tamper evidence skirt.

  As is well known, a synthetic resin container lid for a beverage container having a cylindrical mouth and neck portion having a male thread and a locking jaw located below the male thread on the outer peripheral surface. For example, as disclosed in Patent Document 1 below, a circular top surface wall and a cylindrical skirt wall hanging from the periphery of the top surface wall are provided, and a rupture line extending in the circumferential direction is formed on the skirt wall. The skirt wall is divided into a main part above the breaking line and a tamper evidence hem below the breaking line. A female thread is formed on the inner peripheral surface of the main part of the skirt wall. Synthetic resin container lids, in which a plurality of locking projections are formed at intervals in the circumferential direction on the inner peripheral surface of the evidence skirt, are widely used in practice.

  The synthetic resin container lid as described above is fitted on the mouth and neck of the container and rotated in the closed rotation direction, that is, clockwise when viewed from above, and the female screw of the container lid is threaded on the male thread of the mouth and neck. It is attached to the mouth and neck by screwing the strips together. The locking protrusion formed on the inner peripheral surface of the tamper evidence skirt is elastically over the locking jaw of the mouth and neck and is positioned below the locking protrusion. When opening the mouth / neck portion of the container to consume the contents of the container, the container lid is rotated in the opening rotation direction, that is, counterclockwise as viewed from above. In this way, the threaded engagement of the female thread with the male thread is gradually released, and the main part of the top wall and the skirt wall of the container lid does not rise with the rotation in the opening direction. The locking protrusion formed on the peripheral surface is locked to the locking jaw portion of the mouth and neck portion, and ascending is prevented. Thus, stress is generated in the breaking line, the breaking line is broken, and the tamper evidence hem portion Is separated from the main part of the skirt wall. After that, the tamper-evidence hem is left in the mouth and neck, and the main part of the top wall and skirt wall is freely raised along with the rotation in the opening rotation direction and detached from the mouth and neck. Is opened. In the case of a synthetic resin container lid in which a rupture line extending in the axial direction is formed at the skirt of the tamper evidence, the rupture of the rupture line extending in the circumferential direction is broken not in the circumferential direction but in part. The axially extending break line formed in the tamper evidence hem is broken and the tamper evidence hem is changed from an endless annular shape to an end band shape, thereby The locking of the locking means to the locking jaw of the part is released, and then the entire container lid including the tamper evidence hem is freely raised along with the rotation in the opening rotation direction and detached from the mouth and neck, The mouth and neck are opened.

JP 2011-143942 A

  In the case of the synthetic resin container lid as described above, (1) when the container lid is attached to the mouth and neck of the container, there is a locking protrusion disposed on the inner peripheral surface of the tamper evidence hem. When elastically climbing over the locking jaw of the mouth and neck, it should be ensured that the break line will not be accidentally broken. (2) When opening the mouth and neck of the container It is important that the so-called “slip-out” that causes the container lid to be detached from the mouth and neck without breaking the breaking line is sufficiently reliably avoided. However, the above-mentioned two requirements are not sufficiently satisfied in the conventional synthetic resin container lid of the form as described above, and the break line is accidentally broken when the container lid is attached to the mouth and neck of the container. Alternatively, when opening the mouth and neck of the container, there is a possibility that the entire container lid may be detached from the mouth and neck without breaking the breaking line.

  The present invention has been made in view of the above-mentioned facts, and its main technical problem is to reliably avoid accidental breakage of the break line when the container lid is attached to the mouth and neck of the container. And a new and improved synthetic resin container lid that reliably prevents the container lid from being detached from the mouth and neck without breaking the breaking line when opening the mouth and neck of the container. Is to provide.

  As a result of intensive studies, the present inventors have found that the main technical problem can be achieved by forming a thin portion extending between the locking projections in the axial direction at the skirt portion of the tamper evidence.

That is, according to the present invention, the synthetic resin container lid capable of achieving the main technical problem includes a circular top wall and a cylindrical skirt wall depending from the periphery of the top wall, and the skirt wall A rupture line extending in the circumferential direction is formed in the skirt wall, and the skirt wall is partitioned into a main portion above the rupture line and a tamper evidence skirt below the rupture line. A female thread is formed on the inner peripheral surface of the main portion of the main portion, and a plurality of locking projections are formed on the inner peripheral surface of the tamper evidence skirt portion at intervals in the circumferential direction. In the container lid,
A synthetic resin container lid is provided, characterized in that a thin-walled portion extending in the axial direction between the locking projections is formed in the tamper evidence skirt.

  Preferably, the thin-walled portion is inclined downward in the container lid closing rotation direction and extends linearly. The thin portion is preferably inclined by 30 to 60 degrees with respect to the central axis. It is preferable that one thin portion is formed between each of the locking projections.

  In the synthetic resin container lid constructed according to the present invention, when the container lid is attached to the mouth / neck portion of the container, in particular, the locking projections arranged on the inner peripheral surface of the tamper evidence hem portion are provided on the mouth / neck portion. When the tensile force is generated at the tamper evidence hem when elastically climbing over the locking jaw, the thin part is widened and the circumferential tensile stress is relaxed. The breakage can be avoided with certainty. When the container lid is removed from the mouth and neck of the container, the thin-walled portion is contracted by the circumferential compressive stress generated at the tamper evidence hem by rotation of the container lid in the opening rotation direction. The stop projection is firmly locked to the locking jaw, and it is sufficiently reliably avoided that the container lid is detached from the mouth and neck without breaking the breaking line.

The front view which shows the state which mounted | worn with the suitable embodiment of the synthetic resin container lid comprised according to this invention in the mouth neck part of a container in a cross section. Bottom view of the container lid of FIG.

  Hereinafter, a preferred embodiment of a synthetic resin container lid constructed according to the present invention will be described in more detail with reference to the accompanying drawings.

  Referring to FIGS. 1 and 2, a container lid 2 that can be injection-molded or compression-molded from a suitable synthetic resin such as polyethylene or polypropylene hangs down from a circular top wall 4 and a peripheral edge of the top wall 4. And a cylindrical skirt wall 6. A relatively short cylindrical outer seal piece 10 that hangs downward is formed on the outer peripheral edge of the inner surface of the top wall 4 together with a relatively long cylindrical inner seal piece 8 that hangs downward. An annular protrusion 12 is formed at the outer peripheral surface proximal end portion of the inner seal piece 8.

  The skirt wall 6 has a relatively thick thick upper portion 14 and a relatively thin thin thin portion 16. A rupture line 18 extending in the circumferential direction is formed at the upper end of the thin lower portion 14, and the skirt wall 6 is divided into a main portion 20 above the rupture line 18 and a tamper evidence skirt 22 below the rupture line 18. Has been. In the illustrated embodiment, the breaking line 18 includes a plurality of circumferentially extending slits (cut grooves) 24 and a plurality of bridging portions 26 that remain between the slits 24. The dent skirt 22 is connected to the main portion 20 via a plurality of bridging portions 26.

  On the outer peripheral surface of the main portion 20 of the skirt wall 6, anti-skid knurls 28 are formed which are formed of uneven shapes alternately present in the circumferential direction. On the inner peripheral surface of the main portion 20 of the skirt wall 6, a plurality of notches 32 extending in the axial direction together with the female threads 30 are formed. A plurality of locking protrusions 34 are disposed on the inner peripheral surface of the tamper evidence skirt 22 at intervals in the circumferential direction. In the illustrated embodiment, five locking projections 34 are arranged at equal intervals in the circumferential direction, and the cross-sectional shape of each main portion (portion excluding both ends) of the locking projection 34 is substantially perpendicular. It has a triangular shape and has an upper surface extending in a substantially horizontal direction.

  When the description is continued with reference to FIG. 2 together with FIG. 1, it is important that the tamper evidence skirt 22 is formed with a thin portion 36 extending between the locking projections 34 in the axial direction. In the illustrated embodiment, one thin portion 36 is formed between each of the adjacent locking projections 34. Each of the thin portions 36 is formed by generating a groove on the inner peripheral surface of the tamper evidence skirt 22. If desired, the thin-walled portion 36 is formed by generating a groove on the outer peripheral surface of the tamper evidence skirt 22 instead of or in addition to generating a groove on the inner peripheral surface of the tamper evidence skirt 22. You can also. The width of the thin portion 36 may be about 0.3 to 0.7 mm, and the thickness of the thin portion 36 may be about 0.1 to 0.3 mm. Each of the thin portions 36 is preferably extended in a straight line inclined downward in the closing rotation direction of the container lid 2. The inclination angle of the thin portion 36 with respect to the central axis of the container lid 2 is preferably 30 to 60 degrees. In the illustrated embodiment, the thin portion 36 extends from the upper end portion to the lower end edge of the tamper evidence skirt portion 22, but if desired, a portion slightly above the lower end edge of the tamper evidence skirt portion 22. Thus, the thin portion 36 can be terminated.

  FIG. 1 also shows the mouth / neck portion 38 of the container together with the container lid 2. The mouth and neck portion 38 of the container which can be formed from an appropriate synthetic resin such as polyethylene terephthalate, glass or metal thin plate has a cylindrical shape as a whole, and a male screw 40 and a male screw are formed on the outer peripheral surface of the mouth and neck portion 38. A locking jaw portion 42 located below 40 is formed. The locking jaw 42 has an arcuate upper surface whose outer diameter gradually increases downward and a lower surface extending substantially horizontally. Further provided on the outer peripheral surface of the mouth-and-neck portion 38 is a support ring 44 positioned below the locking jaw 42 (this support ring 44 is used for transporting containers as is well known to those skilled in the art). ing.

  When the container lid 2 is attached to the mouth and neck portion 38 after the contents are filled in the container and the mouth neck portion 38 is sealed, the container lid 2 is fitted on the mouth neck portion 38 and the container lid 2 is closed. 1, the female screw 30 of the container lid 2 is screwed to the male screw 40 of the mouth-and-neck portion 38. When the female thread 30 is screwed onto the male thread 40 until the state shown in FIG. 1, the inner seal piece 8 of the container lid 2 enters the mouth neck 40 and is brought into close contact with the inner peripheral surface of the mouth neck 38. The annular protrusion 12 is brought into intimate contact with the top surface of the mouth and neck portion 38, and the outer seal piece 10 is brought into intimate or close proximity with the outer peripheral surface of the mouth and neck portion 38, thus sealing the mouth and neck portion 38.

  The description will be continued with reference to FIG. 1 and FIG. The locking protrusion 34 is elastically over the locking jaw 42 of the mouth-and-neck portion 38 and is positioned below the locking jaw 42. When the locking projection 34 elastically climbs over the locking jaw 42, the inner diameter of the tamper evidence skirt 22 is expanded, and therefore a circumferential tensile stress is generated in the tamper evidence skirt 22. In the container lid 2 configured in accordance with the present invention, since the thin portion 36 is formed at the tamper evidence skirt 22, the thin portion 36 is widened by the circumferential tensile stress, whereby the circumferential tensile stress is reduced. It is alleviated, and thus it is reliably avoided that the break line 18 is accidentally broken.

  When opening the mouth and neck portion 38 to consume the contents, the container lid 2 is rotated in the opening direction, that is, counterclockwise as viewed from above in FIG. Thus, the screwing of the male screw 40 and the female screw 30 is gradually released, and the main portion 20 of the skirt wall 6 is moved upward in the axial direction along with the rotation. On the other hand, the tamper evidence skirt 22 is prevented from moving upward in the axial direction because the locking projection 34 is locked to the locking jaw 42, and thus stress is generated in the bridging portion 26 of the breaking line 18. The bridging portion 26 is broken, and the tamper evidence skirt 22 is separated from the main portion 20 of the skirt wall 6. At this time, circumferential compression stress is generated in the tamper evidence skirt 22 due to frictional resistance against rotation of the container lid 2 in the opening rotation direction, and thereby the thin portion 36 is reduced in width. The locking projection 34 is firmly locked to the locking jaw 42, and thus it is sufficiently reliably avoided that the container lid 2 is detached from the mouth-and-neck portion 38 without breaking the breaking line 18. After the breaking line 18 is broken, the tamper evidence skirt 22 remains in the mouth and neck portion 38, and the top wall 4 of the container lid 2 and the main portion 20 of the skirt wall 6 are free to move upward in the axial direction along with the rotation. Is moved away from the mouth-and-neck portion 38, and thus the mouth-and-neck portion 38 is opened. If desired, an axial break line is formed in the tamper evidence skirt 22 and when the container neck 38 is opened, the axial break line is broken while the break line 18 extends in the circumferential direction. One end of the container lid 2 is maintained without being broken, and the tamper evidence skirt 22 is developed from the endless ring to the end ring, and the entire container lid 2 is detached from the mouth and neck 38 together with the tamper evidence skirt 22. It can also be done.

2: Container lid 4: Top wall 6: Skirt wall 18: Break line 20: Main part 22: Tamper evidence hem part 26: Bridge part 34: Locking protrusion 36: Thin part 38: Mouth and neck part 42: Locking Chin

Claims (4)

A circular skirt wall and a cylindrical skirt wall depending from the peripheral edge of the top wall. A rupture line extending in the circumferential direction is formed in the skirt wall, and the skirt wall is a main skirt wall above the rupture line. And a tamper evidence hem below the break line, and an internal thread is formed on the inner peripheral surface of the main part of the skirt wall, and an inner periphery of the tamper evidence hem In the synthetic resin container lid in which a plurality of locking projections are formed at intervals in the circumferential direction on the surface,
A synthetic resin container lid, characterized in that a thin-walled portion extending in the axial direction between the locking projections is formed at the tamper evidence skirt.   2. The synthetic resin container lid according to claim 1, wherein the thin-walled portion is inclined linearly and extends downward in a container lid closing rotation direction.   The synthetic resin container lid according to claim 2, wherein the thin portion is inclined at 30 to 60 degrees with respect to the central axis.   The synthetic resin container lid according to any one of claims 1 to 3, wherein one thin portion is formed between each of the locking projections.

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