JP6276972B2 - Plastic container lid - Google Patents

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. A plurality of locking protrusions are disposed on the inner peripheral surface of the tamper evidence skirt at intervals in the circumferential direction, and each of the locking protrusions extends radially inward. The present invention relates to a synthetic resin container lid having a stop surface.

  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. A synthetic resin container lid, in which the skirt wall is divided into a main portion above the breaking line and a tamper evidence skirt below the breaking line, is widely used. Female threads are formed on the inner peripheral surface of the main part of the skirt wall. A number of locking projections are disposed on the inner peripheral surface of the tamper evidence skirt at intervals in the circumferential direction, and each of the locking projections has a locking upper surface extending radially inward.

  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 upper surface of the locking projection formed on the peripheral surface is locked to the locking jaw portion of the mouth-neck portion to prevent the rise, thus generating stress in the breaking line and breaking the breaking line. The evidence hem 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 projection of the locking jaw is released from the locking jaw of the part, 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.

Japanese Patent Laid-Open No. 54-83588

  According to the experience of the present inventor, the conventional synthetic resin container lid of the form as described above has (1) a finger or an appropriate tool engaged with the end of the tamper evidence hem, and outward in the radial direction. By rotating the container lid in the opening rotation direction while displacing it, there is no possibility that the entire mouth of the container lid will be detached from the mouth and neck without breaking the breaking line and the mouth and neck may be illegally opened. (2) When the container lid is attached to the mouth / neck portion of the container, the locking protrusion disposed on the inner peripheral surface of the tamper-evidence hem portion elastically overcomes the locking jaw portion of the mouth / neck portion. At this time, there is a problem to be solved that the break line may be accidentally broken.

  The present invention has been made in view of the above-mentioned facts, and the main technical problem thereof is to reliably prevent the mouth and neck from being tampered with as described above. It is intended to provide a new and improved synthetic resin container lid in which it is possible to prevent as much as possible the accidental breakage of the break line when mounting the container.

  As a result of intensive studies, the present inventor has ensured that the neck and neck portion are illegally opened as described above when the radially extending length of the locking upper surface of each locking projection is relatively long. In view of the fact that the breaking line tends to be accidentally broken when the container lid is attached to the mouth and neck, the radial extension length of the locking upper surface is x. It has been found that the main technical problem described above can be achieved by disposing a normal locking projection and a specific locking projection whose radial extension length of the locking upper surface is x + α larger than x.

That is, according to the present invention, the synthetic resin container lid for 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 has a circumferential direction. The skirt wall is partitioned into a main portion above the break line and a tamper evidence skirt below the break line, and the main portion of the skirt wall. A female thread is formed on the inner peripheral surface of the tamper-evident skirt, and a plurality of locking projections are disposed on the inner peripheral surface of the tamper evidence skirt at intervals in the circumferential direction. Is a synthetic resin container lid having a locking upper surface extending radially inward,
The locking protrusion includes a normal locking protrusion having a radial extension length of x on the locking upper surface and a unique locking protrusion having x + α having a radial extension length of the locking upper surface larger than x. and de,
There is provided a synthetic resin container lid characterized in that the specific locking projections are arranged in a plurality of specific regions at equal intervals in the circumferential direction .

The specific region is an odd number arranged,該特is diametrically opposite of the different regions preferably no said specific region. In a preferred embodiment, 55 to 65 locking projections including the normal locking projection and the specific locking projection are arranged at equal intervals in the circumferential direction.

  In the synthetic resin container lid of the present invention, the radial extension length of the locking upper surface includes a specific locking projection of x + α larger than x, so that the finger or It is effectively prevented that an appropriate tool is locked and displaced radially outward to damage the locking. On the other hand, the specific locking projection is a part, and the other locking projections are normal locking projections whose radial extension length of the locking upper surface is x, so a container lid is attached to the mouth and neck of the container In particular, the break line may be accidentally broken, especially when the locking protrusions arranged on the inner peripheral surface of the tamper evidence hem elastically move over the locking jaw of the mouth and neck. Is avoided as much as possible.

The front view which shows a suitable embodiment of the synthetic resin container lid comprised according to this invention in part in a cross section. The bottom view of the container lid of FIG. The fragmentary sectional view which shows the latching protrusion in the container lid shown in 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 FIG. 1, a container lid 2 that can be injection-molded or compression-molded from a suitable synthetic resin such as polyethylene or polypropylene includes a circular top wall 4 and a cylindrical skirt depending from the periphery of the top wall 4. 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 16, and the skirt wall 6 is partitioned 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.

  2 and FIG. 3 together with FIG. 1, a number of locking projections 34 a and 34 b are disposed on the inner peripheral surface of the tamper evidence skirt 22 at intervals in the circumferential direction. . The locking protrusions 34a and 34b are arranged in a large number, for example, 55 to 65 (60 in the illustrated embodiment) at equal intervals in the circumferential direction, and the circumferential width of each of the locking protrusions 34a and 34b. Are preferably substantially the same. Each of the locking projections 34a and 34b has locking upper surfaces 36a and 36b extending radially inward, tip surfaces 38a and 38b having a substantially semicircular arc shape in a longitudinal sectional view, and radially outwardly downward. It has guide lower surfaces 40a and 40b extending in an inclined manner. And in the container lid 2 comprised according to this invention, the latching protrusion 34a is a normal latching protrusion whose radial direction extension length of the latching upper surface 36a is x, and the latching protrusion 34b is the latching upper surface 36b. It is important that the radial extension length is a unique locking projection having x + α larger than x. α is 0.2 mm, and is preferably about 0.1 to 0.3 mm. In the illustrated embodiment, each of the five singular regions 42 arranged at equal intervals in the circumferential direction is provided with three singular locking protrusions 34b. Usually, a locking projection 34a is provided. In the illustrated embodiment, the radial extending lengths of the three specific locking projections 34b are all set to be the same, but the radial extending lengths of the specific locking projections 34b located at the center in the circumferential direction are the same. The radial extension length of the specific locking projections 34b on both sides in the circumferential direction can be set to x + α2 (α1> α2) as x + α1. It is desirable that an odd number of the singular regions 42 where the singular locking projections 34b are disposed are arranged at equal intervals in the circumferential direction, and the singular region 42 does not exist on the opposite side of the singular region 42 in the diameter direction. The number of normal locking projections 34a, the radial extension length x of the locking upper surface 36a of the normal locking projection 34a, the number of specific locking projections 34b, and the radial extension of the locking upper surface 36b of the specific locking projection 34b The length x + α depends on the hardness of the synthetic resin material forming the container lid 2, the thickness of the tamper evidence skirt 22, the shape of the locking jaw in the mouth and neck of the container to which the container lid 2 is applied, and the like. Based on this, it can be set appropriately.

  FIG. 1 also shows the mouth / neck portion 44 of the container together with the container lid 2. The mouth and neck portion 44 of a container that can be formed from a suitable synthetic resin such as polyethylene terephthalate, glass, or a metal thin plate has a cylindrical shape as a whole. A locking jaw portion 48 located below 46 is formed. The locking jaw portion 48 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 / neck portion 44 is a support ring 50 located below the locking jaw portion 48 (the support ring 50 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 44 after the contents are filled in the container and the mouth and neck portion 44 is sealed, the container lid 2 is fitted on the mouth and neck portion 44 and the container lid 2 is closed. 1, the female screw 30 of the container lid 2 is screwed to the male screw 46 of the mouth-and-neck portion 44. When the female thread 30 is screwed onto the male thread 46 until the state shown in FIG. 1, the inner seal piece 8 of the container lid 2 enters the mouth neck part 44 and is brought into close contact with the inner peripheral surface of the mouth neck part 44. The annular protrusion 12 is brought into close contact with the top surface of the mouth-and-neck portion 44, and the outer seal piece 10 is brought into intimate contact with or close to the outer peripheral surface of the mouth-and-neck portion 44, thus sealing the mouth-and-neck portion 44.

  When the description is continued with reference to FIG. 1, when the container lid 2 is attached to the mouth / neck portion 44 and the mouth / neck portion 44 is sealed, the tamper-evidence hem portion 22 is disposed on the inner peripheral surface. The normal locking protrusions 34 a and the specific locking protrusions 34 b elastically ride over the locking jaws 48 of the mouth / neck 44 and are positioned below the locking jaws 48. At this time, the normal locking projections 34a and the specific locking projections 34b are gradually displaced outward in the radial direction by the guiding action of the guide lower surfaces 40a and 40b of the normal locking projections 34a and the specific locking projections 34b. Get over the stop jaw 48. As described above, the radial extension length of the specific locking projection 34b located at the center in the circumferential direction is x + α1, and the radial extension length of the specific locking projections 34b on both sides in the circumferential direction is x + α2 (α1> α2). In this case, the specific locking projection 34b can get over the locking jaw 48 more smoothly. The radial extension length x + α of the locking upper surface 36b of the specific locking projection 34b is relatively large, but the radial extension length x of the locking upper surface 36a of the normal locking projection 34a is relatively small. It is avoided as much as possible that the breaking line 18 is accidentally broken when the normal locking projection 34a and the specific locking projection 34b elastically move over the locking jaw 48. In particular, an odd number of singular regions 42 where the singular locking protrusions 34b are arranged are arranged at equal intervals in the circumferential direction, and when there is no singular region 42 on the opposite side of the diametric region 42 in the diameter direction, When the locking protrusion 34a and the specific locking protrusion 34b elastically cross the locking jaw portion 48, it is more reliably avoided that the breaking line 18 is accidentally broken.

  When opening the mouth-and-neck portion 44 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 thread 46 and the female thread 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 normal locking projection 34 a and the specific locking projection 34 b are locked to the locking jaw 48, and thus the bridging portion of the breaking line 18. Stress is generated at 26, the bridging portion 26 is broken, and the tamper evidence skirt 22 is separated from the main portion 20 of the skirt wall 6. After the breaking line 18 is broken, the tamper evidence skirt 22 is left on the mouth and neck portion 44, 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 / neck 44 and thus the mouth / neck 44 is opened. If desired, an axial break line is formed in the tamper evidence skirt 22 and when the container neck 44 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 expanded from the endless ring to the end ring, and the entire container lid 2 is detached from the mouth and neck 44 together with the tamper evidence skirt 22. It can also be done.

  In the container lid 2 constructed according to the present invention, the locking upper surface 36b is extended in the radial direction in each of the singular regions 42 in addition to the normal locking projection 34a having a relatively small radial extension length x of the locking upper surface 36a. A unique locking projection 34b having a relatively long protruding length x + α is provided. Therefore, the break line 18 is broken by rotating the container lid 2 in the opening rotation direction while engaging a finger or an appropriate tool at the end of the tamper evidence skirt 22 and displacing it radially outward. The entire container lid 2 can be removed from the mouth / neck portion 44 without being opened, and the mouth / neck portion 44 can be prevented from being opened illegally.

2: Container lid 4: Top wall 6: Skirt wall 18: Break line 20: Main part 22: Tamper evidence hem part 26: Bridge part 30: Female thread 34a: Normal locking protrusion 34b: Specific locking protrusion 36a : Locking upper surface of normal locking projection 36b: locking upper surface of specific locking projection 38a: tip surface of normal locking projection 38b: tip surface of specific locking projection 40a: guide lower surface of normal locking projection 40b: specific relationship Guide lower surface of stop projection 42: Singular region 44: Mouth and neck 46: Male thread 48: Locking jaw

Claims (3)

A circular skirt wall and a cylindrical skirt wall depending from the peripheral edge of the top wall. 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 The surface is provided with a number of locking projections spaced apart in the circumferential direction, and each of the locking projections is a synthetic resin container lid having a locking top surface extending radially inward,
The locking protrusion includes a normal locking protrusion having a radial extension length of x on the locking upper surface and a unique locking protrusion having x + α having a radial extension length of the locking upper surface larger than x. and de,
The synthetic resin container lid, wherein the specific locking projections are arranged in a plurality of specific regions at equal intervals in the circumferential direction . Said specific region is an odd number arranged,該特is diametrically opposite of the different regions no said specific region, the synthetic resin container closure of claim 1, wherein. 3. The synthetic resin container lid according to claim 1, wherein 55 to 65 locking protrusions including the normal locking protrusion and the specific locking protrusion are arranged at equal intervals in the circumferential direction.

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