JP7302959B2 - Synthetic resin container lid - Google Patents

Description

In the present invention, the inner peripheral surface of the tamper-evident hem portion of the skirt wall is formed with locking means composed of a plurality of locking ridges extending in the circumferential direction, and The present invention relates to a synthetic resin container lid in which a fitting portion having a fitting surface whose inner diameter gradually increases upward from the upper surface of a locking projection is formed.

As is well known, a male thread and a locking jaw positioned below the male thread are disposed on the outer peripheral surface of the mouth and neck portion which is formed of glass, synthetic resin or thin metal plate and has a cylindrical shape. A container lid for a container is provided with a circular top wall and a cylindrical skirt wall hanging down from the periphery of the top wall. The skirt wall is divided into a main portion above the breaking line and a tamper-evident bottom portion below the breaking line. Synthetic resin container lids are widely used in practice. A female thread is formed on the inner peripheral surface of the main portion of the skirt wall, and a locking means is formed on the inner peripheral surface of the tamper-evident bottom portion. The locking means comprises a plurality of radially inwardly projecting and circumferentially extending locking ridges .

When sealing the mouth and neck of a container filled with contents, the container lid is fitted over the mouth and neck and rotated in the closing rotation direction so that the male thread of the mouth and neck engages the female thread of the container lid. screw together. Thus, when the container lid is properly attached to the mouth/neck, the locking means of the container lid resiliently overcomes and lies below the locking jaws of the mouth/neck. When opening the mouth and neck to consume the contents of the container, the container lid is rotated in the opening direction. Thus, the container lid is lifted with respect to the mouth/neck portion in accordance with the disengagement of the male thread and the female thread. When the container lid is lifted somewhat, the locking means of the container lid are locked into the locking jaws of the mouth and neck, thereby preventing the tamper-evident skirt from rising. When the container lid continues to rotate in the opening direction, the circumferential break line formed on the skirt wall is broken, and the tamper-evident bottom portion of the skirt wall is separated from the main portion (or the tamper-evident bottom portion If an axial break line is formed in the main part, the axial break line is broken and the tamper-evident bottom part develops from an endless ring to a band with ends, and the tamper-evident bottom part is completely separated from the main part. continue to be connected to the main part in a part of the circumferential direction without being connected). When the container lid continues to rotate in the opening direction, the container lid (or the entire container lid including the tamper-evident bottom) is detached from the mouth and neck with the tamper-evident bottom remaining. to be unsealed.

In Patent Document 1 below, the inner peripheral surface of the tamper-evident hem part is described in order to avoid the so-called slip-off in which the entire container lid is detached from the mouth and neck of the container without breaking the breaking line. 2, 3, 4, 5, 7, 8, 9, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, and 11, disclose forming a fitting portion having an annular fitting surface which is continuous in the circumferential direction and whose radial inner diameter gradually increases upward from the upper surface of the locking ridge. In a container lid formed with such a fitting portion, when the locking projection is locked to the lower surface of the locking jaw portion of the mouth/neck portion, the fitting surface of the fitting portion is not in contact with the locking jaw. The bottom portion of the tamper-evident hem is prevented from being elastically deformed or displaced by being brought into close contact with the outer peripheral surface of the tamper-evident portion. However, if the fitting portion having the fitting surface as described above is formed, the required torque (generally referred to as "first torque") at the start of rotation of the container lid when separating the container lid from the mouth and neck of the container. The required torque between the required torque for breaking the break line (generally called "second torque") does not become a sufficiently small value, and the consumer feels uncomfortable, that is, the container lid It has been found to give a so-called drag feeling that resists rotation.

Japanese Unexamined Patent Application Publication No. 2002-200003 proposes roughening the fitting surface of the fitting portion in order to reduce the required torque between the first torque and the second torque. In addition, in Patent Document 3 below, a locking means is configured to flow down a cleaning liquid that is sprayed onto the mouth and neck in order to clean the contents adhering to the mouth and neck when the contents are filled into the container. It is disclosed that the fitting portion is omitted between a plurality of locking projections to define a drainage channel. Omitting the fitting portion between the locking ridges reduces the contact area between the locking jaws and the fitting surface, and reduces the required torque between the first torque and the second torque to some extent. reduced.

JP 2013-126881 A JP 2016-155589 A Japanese Patent Application Laid-Open No. 2016-16900

Therefore, according to the container lids disclosed in Patent Documents 2 and 3, the required torque between the first torque and the second torque is greater than that of the container lid disclosed in Patent Document 1. Although it is somewhat reduced, according to the experience of the present inventors, the reduction in the necessary torque between the first torque and the second torque is still not sufficient, and consumers feel uncomfortable, that is, the container lid is stuck. Giving a so-called drag feeling that resists rotation cannot be avoided with sufficient certainty.

The present invention has been made in view of the above facts, and the first technical problem thereof is to provide a new and improved synthetic resin in which the required torque between the first torque and the second torque is sufficiently reduced. To provide a manufacturing container lid.

A second technical problem of the present invention is that, in addition to achieving the above first technical problem, an undercut is formed on the inner peripheral surface of the tamper-evident skirt portion due to the presence of the locking ridge. As a result, when the molded container lid is taken out from the mold, so-called forcible extraction occurs, and although a relatively large force is applied to both ends of the locking projection in the circumferential direction, the locking projection does not move. To provide a new and improved synthetic resin container lid in which deformation of both ends in the circumferential direction is suppressed.

A third technical object of the present invention is to achieve the above first and second technical objects, and in addition, each of the plurality of locking ridges constituting the locking means is arranged so that the bottom portion of the tamper evidence is An upper surface extending radially inward from the inner peripheral surface, a lower surface whose inner diameter gradually increases downward, and an inner surface located at the boundary between the upper surface and the lower surface, and both circumferential ends of the locking projection. , the radially inwardly extending length of the upper surface is gradually reduced toward both ends in the circumferential direction and/or the lower end of the lower surface is gradually displaced upward toward both ends in the circumferential direction. Even if both ends of the strip have lower rigidity than the central part, deformation of the both ends of the locking protrusion can be reliably avoided when the molded container lid is removed from the mold. An object of the present invention is to provide an improved synthetic resin container lid.

As a result of intensive studies, the inventors of the present invention have found that by forming a plurality of fitting portions having fitting surfaces at intervals in the circumferential direction and appropriately setting the arrangement of the fitting portions in the circumferential direction, the above-mentioned It has been found that one technical object can be achieved and also the second and third technical objects can be achieved together with the first technical object.

According to the present invention , as a synthetic resin container lid that achieves the first technical object,
It comprises a circular top wall and a cylindrical skirt wall hanging down from the periphery of the top wall, the skirt wall having a plurality of circumferentially spaced slits extending in the circumferential direction and a plurality of slits existing between the slits. The skirt wall is divided into a main portion above the break line and a tamper-evident bottom portion below the break line. A female thread is formed on the inner peripheral surface of the main portion, and a plurality of locks protruding radially inward and extending in the circumferential direction are formed on the inner peripheral surface of the tamper-evident skirt portion. In a synthetic resin container lid provided with a locking means composed of a ridge,
On the inner peripheral surface of the tamper evident hem, a fitting portion having a fitting surface whose inner diameter gradually increases upward from the upper surface of the locking protrusion when viewed in the vertical direction is provided. are arranged at intervals in the circumferential direction, and the fitting portions are arranged corresponding to at least both ends of the locking projection in the circumferential direction. A synthetic resin container lid is provided .

The second technical object of the present invention is achieved by adopting a form in which the fitting portions are arranged corresponding to both ends of the locking projection in the circumferential direction.

The third technical problem of the present invention is that each of the locking ridges has an upper surface extending radially inward from the inner peripheral surface of the tamper-evident skirt portion, and the inner diameter gradually increases downward. It has a lower surface and an inner surface positioned at the boundary between the upper and lower surfaces, and the radially inwardly extending length of the upper surface extends toward both circumferential ends at both circumferential ends of the locking projection. and/or the lower end of the lower surface is gradually displaced upward toward both ends in the circumferential direction,
One fitting portion having a relatively large circumferential width is provided corresponding to each of the circumferentially opposite end portions of the locking ridge, and corresponding to the circumferentially central portion of the locking ridge. This is achieved by forming a form in which at least one fitting portion having a relatively small circumferential width is provided.

The fitting surface of the fitting portion is preferably a rough surface having an arithmetic average roughness (Ra) defined in JIS B0601 of 2 to 20 μm.

In the synthetic resin container lid of the present invention, a plurality of fitting portions are appropriately arranged at intervals in the circumferential direction instead of the fitting portion continuously extending in the circumferential direction. The contact area between the outer peripheral surface of the locking jaw portion of the neck and the fitting surface of the fitting portion is greatly reduced, resulting in a sufficiently reduced torque required between the first torque and the second torque. be done.

In the case of the configuration in which the fitting portions are arranged corresponding to both ends of the locking projection in the circumferential direction, the engagement is caused by the existence of the fitting portions arranged at both ends in the circumferential direction. Since the ribs are reinforced, deformation of both ends of the locking ribs is suppressed even if the locking means is forcibly pulled out when the molded container lid is removed from the molding die.

Each of the locking projections has an upper surface extending radially inward from the inner peripheral surface of the tamper-evident skirt portion, a lower surface whose inner diameter gradually increases downward, and a boundary between the upper surface and the lower surface. The radially inwardly extending length of the upper surface is gradually reduced at both circumferential ends of the locking ridge and/or the lower end of the lower surface is In the case of the configuration in which the locking protrusion is gradually displaced upward toward both ends in the circumferential direction, the rigidity of both ends of the locking protrusion is reduced, but the circumferential width corresponding to each of the ends of the locking protrusion in the circumferential direction is reduced. If one fitting portion having a relatively large width in the direction is provided, forcible removal of both ends of the locking means when the molded container lid is taken out from the molding die can be prevented due to the relatively large width in the circumferential direction. This is mitigated by the presence of the large fitting portion, and it is reliably avoided that the ends of the locking ridge are deformed when the molded container lid is removed from the mold.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view, partly in cross section, of a preferred embodiment of a synthetic resin container lid constructed in accordance with the present invention ; The figure which expands and shows a part of mouth-and-neck part of the container lid shown in FIG. 1, and the container with which this was mounted|worn. The figure which expand|deploys and shows the tamper evidence hem part of the container lid shown in FIG .

BEST MODE FOR CARRYING OUT THE INVENTION A preferred embodiment of a synthetic resin container lid constructed according to the present invention will be described in further detail below with reference to the accompanying drawings.

Referring to FIG. 1, a container lid 2, which 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. walls 6; A relatively long tubular inner seal piece 8 that hangs downward and a relatively short tubular outer seal piece 10 that hangs downward are formed on the outer peripheral edge of the inner surface of the top wall 4 .

A fracture line 12 extending in the circumferential direction is formed in the skirt wall 6, and the skirt wall 6 is divided into a main portion 14 above the fracture line 12 and a tamper-evident bottom portion 16 below the fracture line 12. . The fracture line 12 is composed of a plurality of slits (cut grooves) 18 extending in the circumferential direction at intervals in the circumferential direction and a plurality of bridging portions 20 existing between the slits 18. 16 is connected to main section 14 via a plurality of bridging sections 20 .

Anti-slip knurls 22 are formed on the outer peripheral surface of the main portion 14 of the skirt wall 6. The non-slip knurls 22 are composed of uneven shapes alternately present when viewed in the circumferential direction. A female thread 24 is formed on the inner peripheral surface of the main portion 14 of the skirt wall 6 . A plurality of thread height reduction portions 26 are provided on the female thread 24 at intervals in the circumferential direction.

Locking means 27 are arranged on the inner peripheral surface of the tamper-evident skirt portion 16 . In the illustrated embodiment, the locking means 27 consist of a plurality of (five in the illustrated embodiment) locking ridges 28 projecting radially inward and extending in the circumferential direction. Referring to FIG. 2 together with FIG. 1, the vertical cross-sectional shape of each main portion (portions other than both ends) of each of the locking ridges 28 is a substantially right-angled triangular shape. It has an upper surface 30 extending radially inward from the inner peripheral surface of the evidence skirt portion 16, a lower surface 32 whose inner diameter gradually increases downward, and an inner surface 34 located at the boundary between the upper surface 30 and the lower surface 32. ing. At both circumferential ends of the locking projection 28, the radially inwardly extending length of the upper surface 30 is gradually reduced toward both circumferential ends, and/or the lower end of the lower surface 32 is gradually reduced toward both circumferential ends. It is preferably displaced upwards. In the illustrated embodiment, the radially inwardly extending length of the upper surface 30 at the circumferential ends of the locking ridge 28 (although not necessarily clearly shown) gradually increases toward the circumferential ends. The lower end of the lower surface 32 is gradually displaced upward toward both ends in the circumferential direction.

An annular ridge 36 that protrudes radially inward is also formed on the inner peripheral surface of the tamper-evident skirt portion 16 . As can be clearly understood by referring to FIG. 2, the annular protrusion 36 is provided at a portion connected to the upper surface 30 of the locking protrusion 28 when viewed in the vertical direction. Continuing the description with reference to FIG. 3 together with FIG. 1, in the container lid of the present invention, a It is important that a plurality of fitting portions 40 having fitting surfaces 38 whose inner diameter gradually increases upward are arranged at intervals in the circumferential direction with respect to each of the locking projections 28 . . In the illustrated embodiment, one fitting portion 40a having a relatively large circumferential width is provided corresponding to each of the circumferential ends of the locking ridge 28, and the locking ridge 28 is fitted in the circumferential direction. A plurality of (three in the illustrated embodiment) fitting portions 40b having relatively small circumferential widths are provided corresponding to the central portion. Focusing on one locking projection 28, the plurality of fitting portions 40 formed on the upper surface 30 of the locking projection 28 are all equally spaced in the circumferential direction. Each of the fitting surfaces 38 of the fitting portion 40 extends upward from the upper surface of the locking projection 28 . Here, as shown in FIG. 3, the circumferential width of the fitting portion 40a having a relatively large circumferential width is d1, the circumferential width of the fitting portion 40b having a relatively small circumferential width is d2, and one locking projection A plurality of fitting portions 40 formed on the upper surface 30 of the ridge 28 are spaced apart in the circumferential direction by d3, and fitting portions 40a adjacent in the circumferential direction in two locking projections 28 arranged adjacent in the circumferential direction. Assuming that the circumferential interval is d4, d1=3d2, d3=2d2, and d4=d2. The vertical cross-sectional shape of the fitting surface 38 is arcuate, and the fitting surface 38 and the inner surface of the annular ridge 36 are substantially flush with each other. If desired, mating surface 38 may have a linear longitudinal cross-sectional shape and the inner surface of annular ridge 36 may be positioned radially outwardly of mating surface 38 . Further, in the illustrated embodiment, the fitting surface 38 is a rough surface with an arithmetic average roughness (Ra) defined in JIS B0601 of 2 to 20 μm.

As in the illustrated embodiment, each of the locking ridges 28 has an upper surface 30 extending radially inward from the inner peripheral surface of the tamper-evident skirt 16, a lower surface 32 having a gradually increasing inner diameter downward, and an inner surface 34 located at the boundary between the upper surface 30 and the lower surface 32, and the radially inwardly extending length of the upper surface 30 extends toward both circumferential ends at both circumferential ends of the locking projection 28. In the case of a configuration in which the lower end of the lower surface 32 is gradually reduced and/or the lower end of the lower surface 32 is gradually displaced upward toward both ends in the circumferential direction, the rigidity of both ends of the locking ridge 28 is reduced, but the rigidity of the locking ridge 28 is reduced. If one fitting portion 40a having a relatively large circumferential width is provided corresponding to each of the circumferentially opposite ends, the locking means 27 ( Forcible removal of both ends of the locking ridge 28) is mitigated by the presence of the fitting portion 40a having a relatively large circumferential width, and both ends of the locking ridge 28 are removed when the molded container lid is removed from the mold. It is possible to reliably avoid deformation of the part.

FIG. 1 also shows the mouth-and-neck portion 42 of the container together with the container lid 2 . The mouth-and-neck portion 42 of the container, which can be made of an appropriate synthetic resin such as polyethylene terephthalate, glass, or thin metal plate, has a cylindrical shape as a whole. A locking jaw 46 located below 44 is formed. The locking jaw 46 has an arcuate upper surface with a downwardly gradually increasing outer diameter, a cylindrical outer peripheral surface and a substantially horizontally extending lower surface. Also disposed on the outer peripheral surface of mouth/neck portion 42 is a support ring 48 positioned below locking jaws 46 (such support ring 48 is used for transporting containers, as is well known to those skilled in the art). ing.

After filling the container with the contents, normally, prior to attaching the container lid 2 to the mouth-and-neck portion 42 of the container, a washing liquid, which may be clean water, is sprayed on the outer peripheral surface of the mouth-and-neck portion 42 to clean the mouth. The contents adhering to the outer peripheral surface of the neck 42 are washed. After that, the container lid 2 is fitted onto the mouth/neck portion 42, and the container lid 2 is rotated in the closing rotation direction, which is clockwise when viewed from above in FIG. 42 is screwed into the male thread 44. When the female thread 24 is screwed into the male thread 44 to the state shown in FIG. , the outer seal piece 10 is brought into intimate contact with the outer peripheral surface of the mouth/neck portion 42, and thus the mouth/neck portion 42 is sealed. The locking projection 28 disposed on the inner peripheral surface of the tamper-evident bottom portion 16 elastically engages the locking jaw portion 46 of the mouth/neck portion 42 (that is, by elastic deformation or displacement of the tamper-evident bottom portion 16). ) over and below the locking jaw 46 . In such a state, as understood by referring to FIG. 2 together with FIG. It is brought into contact with or brought into close contact with the lower end of the outer peripheral surface of the locking jaw 46 . After the container lid 2 is attached to the mouth/neck portion 42 as required, a cleaning liquid, which may be clean water, is sprayed onto the container lid 2, and then a dry gas, which may be air, is sprayed onto the container lid following the spraying of the cleaning liquid. to remove the wash water. The cleaning liquid that has been sprayed onto the mouth/neck portion 42 of the container and remains on the mouth/neck portion 42 flows out from between the engaging ridges 28 that are arranged at intervals in the circumferential direction.

When opening the mouth/neck portion 42 to consume the contents, the container lid 2 is rotated in the opening direction, that is, counterclockwise when viewed from above in FIG. Thus, the male thread 44 and the female thread 24 are gradually unscrewed, and the main part 14 and the tamper-evident bottom part 16 are raised with respect to the mouth/neck part 42 along with the rotation. At this time, as understood by referring to FIG. 2, the inner diameter gradually increases upward from the inner surface of the fitting portion 40 provided in the tamper-evident skirt portion 16, that is, the upper surface of the locking projection 28. Since the fitting surface 38 is brought into close contact with the lower end of the outer peripheral surface of the locking jaw portion 46 of the mouth/neck portion 42, resistance torque is generated due to friction. Since the portions 40 do not extend continuously in the circumferential direction, but are appropriately arranged at intervals in the circumferential direction, the outer peripheral surface of the locking jaw portion 46 of the mouth/neck portion 42 and the fitting portion 40 contact area with the fitting surface 38 is greatly reduced, and as a result, the required torque between the first torque and the second torque is sufficiently reduced. When the container lid 2 is raised with respect to the mouth-and-neck portion 42 by a predetermined amount, the locking projection 28 is locked by the locking jaw portion 46 to prevent the tamper-evident skirt portion 16 from moving upward in the axial direction. be done. As a result, a stress is generated in the bridging portion 20 of the breaking line 12 to break the bridging portion 20 , and the tamper-evident skirt portion 16 is separated from the main portion 14 of the skirt wall 6 . When the breaking line 12 is broken, the inner surface of the fitting portion 40 provided in the tamper-evident bottom portion 16, that is, the fitting surface whose inner diameter gradually increases upward from the upper surface of the locking protrusion 28. 38 is brought into close contact with the lower end of the outer peripheral surface of the locking jaw portion 46 of the mouth/neck portion 42, elastic deformation or displacement of the tamper evident hem portion 16 is suppressed, and the breaking line 12 is engaged without being broken. It is possible to sufficiently reliably prevent the stop projection 28 from climbing over the locking jaw portion 46 and rising. After the break line 12 is broken, the tamper-evident bottom portion 16 remains in the mouth-neck portion 42, and the top wall 4 of the container lid 2 and the main portion 14 of the skirt wall 6 are free to move upward in the axial direction as they rotate. and is separated from the mouth/neck section 42, and thus the mouth/neck section 42 is unsealed. If desired, an axial break line is formed in the tamper-evident bottom portion 16 so that the axial break line is broken when opening the mouth-neck portion 42 of the container, while the break line 12 extending in the circumferential direction is broken. is maintained without being partially broken, the tamper-evident bottom portion 16 is expanded from an endless annular shape to an endless annular shape, and the entire container lid 2 is separated from the mouth-and-neck portion 42 together with the tamper-evident bottom portion 16. You can also make it

In the synthetic resin container lid shown in FIG. 1, both circumferential side surfaces of the fitting portion 40 extend linearly in the radial direction. Although they are connected vertically, the fitting surface 38 and both circumferential side surfaces of the fitting portion 40 may be connected in a curved line. By connecting the fitting surface 38 and both circumferential side surfaces of the fitting portion 40 in a curved line, the container lid 2 is rotated in the opening direction, and the fitting surface 38 engages the locking jaw portion 46 of the mouth/neck portion 42 . is brought into close contact with the lower end portion of the outer peripheral surface of the body to reduce the frictional resistance therebetween when moving in the circumferential direction against it. The frictional resistance can be further reduced by appropriately forming holes in the fitting surface 38 . Moreover, the respective upper end portions of the plurality of fitting portions 40 do not necessarily have to be aligned in the circumferential direction when viewed in the vertical direction. Furthermore, a reinforcing portion having a larger inner diameter than the fitting portion 40 may be appropriately provided between the fitting portions 40 adjacent in the circumferential direction .

2 : Container lid 4: Top wall 6: Skirt wall 12: Breaking line 14: Main part 16: Tamper evident hem part 18: Slit 20: Bridging part 24: Female thread 27: Locking means 28: Locking protrusion Article 38: Fitting surface 40: Fitting part

Claims (3)

It comprises a circular top wall and a cylindrical skirt wall hanging down from the periphery of the top wall, the skirt wall having a plurality of circumferentially spaced slits extending in the circumferential direction and a plurality of slits existing between the slits. The skirt wall is divided into a main portion above the break line and a tamper-evident bottom portion below the break line. A female thread is formed on the inner peripheral surface of the main portion, and a plurality of locks protruding radially inward and extending in the circumferential direction are formed on the inner peripheral surface of the tamper-evident skirt portion. In a synthetic resin container lid provided with a locking means composed of a ridge,
On the inner peripheral surface of the tamper evident hem, a fitting portion having a fitting surface whose inner diameter gradually increases upward from the upper surface of the locking protrusion when viewed in the vertical direction is provided. are arranged at intervals in the circumferential direction, and the fitting portions are arranged corresponding to at least both ends of the locking projection in the circumferential direction. Characteristic synthetic resin container lid. Each of the locking projections has an upper surface extending radially inward from the inner peripheral surface of the tamper-evident skirt portion, a lower surface whose inner diameter gradually increases downward, and a boundary between the upper surface and the lower surface. The radially inwardly extending length of the upper surface is gradually reduced at both circumferential ends of the locking ridge and/or the lower end of the lower surface is It is gradually displaced upward toward both ends in the circumferential direction,
One fitting portion having a relatively large circumferential width is provided corresponding to each of the circumferentially opposite end portions of the locking ridge, and corresponding to the circumferentially central portion of the locking ridge. 2. The synthetic resin container lid according to claim 1, wherein at least one fitting portion having a relatively small circumferential width is provided. 3. The synthetic resin container lid according to claim 1 , wherein the fitting surface of the fitting portion is a rough surface having an arithmetic mean roughness (Ra) defined in JIS B0601 of 2 to 20 μm.

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