JP2023118381A - Synthetic resin-made container lid - Google Patents

Abstract

To provide a new synthetic resin-made container lid which can reduce resistance when engagement means 32 elastically gets over an engagement jaw part 104 of a mouth neck part 100 in a process of mounting a container lid on the mouth neck part of the container while reducing a used amount of a material.SOLUTION: Lightened parts 44 are provided on not only an upper surface of engagement means 32 but also a lower surface 42 thereof.SELECTED DRAWING: Figure 1

Description

The present invention relates to a synthetic resin container lid.

According to the present invention, the inner peripheral surface of the tamper-evident skirt portion of the skirt wall is composed of a plurality of locking projections extending in the circumferential direction or an annular locking projection extending continuously in the circumferential direction. The present invention relates to a synthetic resin container lid having locking means.

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 skirt main portion above the break line and a tamper-evident bottom portion below the break line. Synthetic resin container lids are widely used in practice. A female thread is formed on the inner peripheral surface of the skirt main portion, and a locking means is formed on the inner peripheral surface of the tamper-evident hem portion. The locking means comprises a plurality of radially inwardly projecting and circumferentially extending locking projections or a radially inwardly projecting and circumferentially continuous annular locking ridge. there is The inner peripheral edge of the main portion of the locking means continues in the circumferential direction along the inner peripheral surface of the tamper-evident bottom portion.

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 hem of the skirt wall is separated from the skirt main portion (or the tamper-evident hem If an axial break line is formed in the part, the axial break line is broken and the tamper-evident hem expands from an endless ring to a band with ends, and the tamper-evident hem is completely separated from the main part of the skirt. continue to be connected to the skirt main part in a part of the circumferential direction without being separated into two). 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 recent years, from the viewpoint of reducing environmental load and manufacturing costs, it is required to reduce the amount of material used for manufacturing container lids. Patent Literature 1 listed below discloses an example of a container lid in which the amount of material used is reduced by providing a plurality of hollowed portions at intervals in the circumferential direction on the upper surface of a locking means.

Japanese Patent Application Laid-Open No. 2020-70031

Therefore, in the container lid disclosed in Patent Document 1, when the locking means elastically climbs over the locking jaw portion of the mouth/neck portion in the process of attaching the container lid to the mouth/neck portion of the container, In particular, due to the large contact area between the lower surface of the locking means and the upper surface of the locking jaw, the locking means exerts a large resistance when it elastically climbs over the locking jaw. Therefore, when the locking means elastically climbs over the locking jaw in the above process, the skirt main portion tends to be rotated with respect to the tamper-evident bottom portion, causing the skirt main portion and the tamper-evident bottom portion to be separated. There is a risk that the connecting bridging portion will be stretched and broken. In addition, since the resistance is large, a facility for properly attaching the container lid to the mouth and neck of the container is required, which may increase the manufacturing cost and deteriorate the manufacturing efficiency.

The present invention has been made in view of the above-mentioned facts, and its main technical problem is to reduce the amount of material used for manufacturing the container lid, and to reduce the amount of material used for manufacturing the container lid, and to reduce the amount of material involved in the process of attaching the container lid to the mouth and neck of the container. To provide a new and improved synthetic resin container lid capable of reducing resistance when a stopper means elastically climbs over an engaging jaw part of a mouth and neck part.

As a result of intensive studies, the present inventor found that the above main technical problem can be solved by providing hollowed portions not only on the upper surface of the engaging means but also on the lower surface thereof.

That is, according to the present invention, a synthetic resin container lid that solves the above main technical problems is provided with a circular top wall and a cylindrical skirt wall that hangs down from the peripheral edge of the top wall. A circumferentially extending rupture line is formed by a plurality of circumferentially spaced slits and a plurality of bridging portions between the slits, and the skirt wall is ruptured. It is divided into a skirt main part above the line and a tamper-evident hem part below the breaking line, and a female thread is formed on the inner peripheral surface of the skirt main part, and the tamper-evident hem A plurality of radially inwardly projecting and circumferentially extending locking projections or a radially inwardly projecting annular locking ridge continuously extending in the circumferential direction are formed on the inner peripheral surface of the part. In a synthetic resin container lid, a locking means is disposed, and the inner peripheral edge of the main portion of the locking means continues in the circumferential direction along the inner peripheral surface of the tamper-evident skirt,
A synthetic resin container lid is provided, characterized in that a plurality of lightening portions are formed on the lower surface of the main portion at intervals in the circumferential direction.

Preferably, the inner peripheral edge of the main portion is circumferentially continuous in parallel with the inner peripheral surface of the tamper-evident skirt portion. Preferably, the lower surface of the main portion is downwardly inclined radially outwardly and connected to the inner peripheral surface of the tamper-evident skirt portion. Preferably, when the locking means is composed of a plurality of locking projections, the inner peripheral edges of both ends of the locking projections in the circumferential direction extend from the circumferential ends of the inner peripheral edges of the main portion. It is connected to the inner peripheral surface of the tamper-evident hem portion so as to be inclined radially outward toward the outer side in the circumferential direction. In this case, the lower surface of the end portion is preferably provided with a reinforcing portion whose inner diameter gradually increases downward and which is connected to the inner peripheral surface of the tamper-evident skirt portion.

In the present invention, since the lower surface of the locking means is provided with the lightening portion, the amount of material used for manufacturing the container lid can be reduced, and the container lid can be used as the mouth and neck of the container. When the locking means elastically climbs over the locking jaws of the mouth and neck in the process of attaching to the mouth and neck, the contact area between the lower surface of the locking means and the locking jaws is reduced, and the resistance when climbing over is reduced. The torque and the force itself required to climb over are reduced. When the inner peripheral edge of the main portion of the locking means continues in the circumferential direction parallel to the inner peripheral surface of the tamper-evident skirt portion, the locking projection is less likely to deform, that is, the locking projection has sufficient rigidity. .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial cross-sectional view of a preferred embodiment of a synthetic resin container lid constructed in accordance with the present invention; FIG. 2 is a bottom view of the container lid shown in FIG. 1; 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 inner peripheral surface of the tamper evident hem part of the container lid shown in FIG. FIG. 10 is a diagram showing an expanded inner peripheral surface of a tamper-evident bottom portion in a modification of the container lid configured according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a more detailed description will be given with reference to the accompanying drawings showing a preferred embodiment of a synthetic resin container lid constructed according to the present invention.

1 and 2, a container lid 2, which can be injection molded or compression molded from a suitable synthetic resin such as polyethylene or polypropylene, has a circular top wall 4 and depends from the periphery of the top wall 4. a cylindrical skirt wall 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 . Between the inner seal piece 8 and the outer seal piece, an annular minute ridge 12 slightly projecting downward from the inner surface of the top wall 4 is also formed.

A fracture line 14 extending in the circumferential direction is formed in the skirt wall 6, and the skirt wall 6 is divided into a skirt main portion 16 above the fracture line 14 and a tamper-evident bottom portion 18 below the fracture line 14. there is The fracture line 14 is composed of a plurality of slits (cut grooves) 20 extending in the circumferential direction at intervals in the circumferential direction and a plurality of bridging portions 22 existing between the slits 20. 18 is connected to skirt main portion 16 via a plurality of bridging portions 22 .

Non-slip knurls 24 are formed on the outer peripheral surface of the skirt main portion 16 and are formed of uneven shapes alternately present when viewed in the circumferential direction. A female thread 26 is formed on the inner peripheral surface of the skirt main portion 16 of the skirt wall 6 . A plurality of missing portions 28 are provided on the female thread 26 at intervals in the circumferential direction.

3 and 4 as well as FIGS. 1 and 2, locking means are provided on the inner peripheral surface of the tamper-evident bottom portion 18. As shown in FIG. In the illustrated embodiment, the locking means consist of a plurality (five in the illustrated embodiment) of locking projections 32 projecting radially inward and extending in the circumferential direction. The locking projection 32 has a main portion 34 whose inner peripheral edge continues in the circumferential direction parallel to the inner peripheral surface of the tamper-evident bottom portion 18 , and the main portion 34 located on both sides in the peripheral direction of the main portion 34 and having an inner peripheral edge of the main portion 34 . It is divided into an end portion 36 that is connected to the inner peripheral surface of the tamper-evident skirt portion 18 by sloping radially outward from the peripheral end of the inner peripheral edge toward the outer side in the peripheral direction. As shown in FIG. 3, the upper surface of the main portion 34 of the locking protrusion 32 is composed of a locking upper surface 38 positioned radially inward and extending substantially horizontally, and a locking upper surface 38 positioned radially outward and having an inner diameter increasing upward. It is divided into a fitting upper surface 40 that gradually increases and is connected to the inner peripheral surface of the tamper-evident skirt portion 18 . In the illustrated embodiment, the fitting upper surface 40 has a vertical cross-sectional shape that extends linearly upward and then extends radially outward at an angle. On the other hand, the lower surface 42 of the main portion 34 of the locking projection 32 is connected to the inner peripheral surface of the tamper-evident bottom portion 18 while being inclined downward and radially outward. 1 and 4, a plurality of lightening portions 44 are formed in the lower surface 42 of the main portion 34 at intervals in the circumferential direction. The lightening portion 44 is formed by notching the lower surface 42 of the main portion 34 so that the inner peripheral surface of the tamper-evident skirt portion 18 is exposed, and the lower surface of the notched portion is substantially horizontal. . Referring to FIG. 4, in the illustrated embodiment, four lightening portions 44 are formed at equal intervals in the circumferential direction, and all have the same width in the circumferential direction. A plurality of lightening portions 44 are arranged at equal intervals in the circumferential direction and have the same width in the circumferential direction. The effect of reducing the resistive torque and the resistance to climb over when the locking jaw 32 climbs over is obtained evenly in the circumferential direction. In addition, the circumferential width of the lightening portion 44 is wider than the circumferential width of the residual portion 50 remaining between the two lightening portions 44 adjacent to each other in the circumferential direction, and the residual portion 50 has a rib shape. It's becoming The upper surface of the end portion 36 of the locking protrusion 32 has an inner diameter that gradually increases upward and is connected to the inner peripheral surface of the tamper-evident skirt portion 18 , and the locking upper surface 38 and the fitting upper surface 40 of the main portion 23 are connected to each other. and circumferentially. The lower surface of the end portion 36 is provided with a lower reinforcing portion 52 whose inner diameter gradually increases downward and is connected to the inner peripheral surface of the tamper-evident skirt portion 18. The lower surface of the end portion 36 is lightened. It has not been. Further, in the illustrated embodiment, the inner diameter of the lower reinforcing portion 52 gradually increases in the direction away from the main portion 34 in the radial direction. In addition, the lower edge of the lower surface of the end portion 36 is gradually inclined upward toward the outer side in the circumferential direction. A ridge 54 extending continuously in the circumferential direction between two locking projections 32 arranged adjacent to each other in the circumferential direction is also formed on the inner peripheral surface of the tamper-evident skirt portion 18 . Circumferential ends of the protrusion 46 are connected to circumferential end faces of the locking protrusions 32, respectively.

In FIG. 1, the container lid 2 and the mouth/neck portion 100 of the container are indicated by two-dot chain lines. The mouth/neck portion 100 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 104 located below 102 is formed. Locking jaw 104 has an arcuate upper surface with a downwardly gradually increasing outer diameter, a cylindrical outer peripheral surface and a substantially horizontally extending lower surface. A support ring 106 positioned below the locking jaw 104 is also disposed on the outer peripheral surface of the mouth/neck portion 100 (such support ring 106 is used to transport containers as is well known to those skilled in the art). ing.

After filling the contents in the container, the container lid 2 is fitted onto the mouth-and-neck portion 100, and the container lid 2 is rotated in the closing rotation direction, which is clockwise as viewed from above in FIG. The female thread 26 is screwed into the male thread 102 of the mouth and neck portion 100 . When the female thread 26 is screwed into the male thread 102 to the state shown in FIG. , the outer seal piece 10 is brought into close contact with the outer peripheral surface of the mouth/neck portion 100, and the annular minute ridge 12 is brought into close contact with the top surface of the mouth/neck portion 100, thus sealing the mouth/neck portion 100. As shown in FIG. The locking projections 32 disposed on the inner peripheral surface of the tamper-evident bottom portion 18 elastically engage the locking jaw portion 104 of the mouth/neck portion 100 (that is, by elastic deformation or displacement of the tamper-evident bottom portion 18). It climbs over and is positioned below the locking jaw 104 . When the locking projection 32 elastically rides over the locking jaw portion 104 of the mouth/neck portion 100, the lower surface 42 of the locking projection 32 is inclined downward and radially outward, thereby preventing the tamper-evident hem. The portion 18 is smoothly elastically deformed. In this state, as will be understood by referring to FIG. 3 together with FIG. be kept close.

In the present invention, since the recessed portion 44 is provided on the lower surface 42 of the locking projection 32, the amount of material used for manufacturing the container lid is reduced, and the container lid 2 is When the locking projection 32 elastically climbs over the locking jaw 104 of the mouth/neck portion 100 in the process of attaching to the mouth/neck portion 100 of the container, the lower surface 42 of the locking projection 32 and the locking jaw portion 104 are Since the contact area is reduced, the resistive torque and the force itself required for getting over are reduced. When the inner peripheral edge of the main portion 34 of the locking projection 32 continues in the circumferential direction in parallel with the inner peripheral surface of the tamper-evident skirt portion 18, the locking projection 32 is further difficult to deform. It has sufficient rigidity. Further, the provision of the lower reinforcing portion 52 on the lower surface 42 of the end portion 36 also allows the locking projection 32 to have sufficient rigidity.

When opening the mouth/neck portion 100 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 102 and the female thread 26 are gradually unscrewed, and the skirt main portion 16 and the tamper-evident hem portion 18 are raised with respect to the mouth/neck portion 100 along with the rotation. At this time, as will be understood by referring to FIG. 2 , the fitting upper surface 40 of the locking projection 32 provided on the tamper-evident skirt portion 18 is positioned at the lower end of the outer peripheral surface of the locking jaw portion 104 of the mouth/neck portion 100 . , the resistance torque due to friction gradually increases. When the container lid 2 is raised with respect to the mouth/neck portion 100 by a predetermined amount, the locking upper surface 38 of the locking protrusion 32 is locked to the lower surface of the locking jaw portion 104, and the tamper-evident bottom portion 18 is moved in the axial direction. Upward movement is blocked. At this time, the fitting upper surface 40 of the locking protrusion 32 is brought into close contact with the lower end of the outer peripheral surface of the locking jaw 104 of the mouth/neck portion 100 , so that the tamper evident skirt 18 is attached to the locking jaw 104 . strongly held. Then, by preventing the upward movement of the tamper-evident bottom portion 18 in the axial direction, stress is generated in the bridge portion 22 of the fracture line 14 , the bridge portion 22 is broken, and the tamper-evident bottom portion 18 is broken. is separated from the main skirt portion 16 . After the break line 14 is broken, the tamper-evident hem portion 18 remains in the mouth/neck portion 100, and the top wall 4 of the container lid 2 and the skirt main portion 16 of the skirt wall 6 are rotated upward in the axial direction. It is freely moved and detached from the mouth/neck part 100, and thus the mouth/neck part 100 is unsealed. If desired, an axial break line is formed in the tamper-evident bottom portion 18 so that the axial break line is broken when the container neck portion 100 is opened, while the circumferentially extending break line 14 is formed. is maintained without being partially broken, the tamper-evident skirt portion 18 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 100 together with the tamper-evident skirt portion 18. You can also make it

In the embodiments described above, the locking means consisted of a plurality of radially inward and circumferentially extending locking projections, but as in the variant shown in FIG. It may consist of a single radially inwardly projecting and circumferentially continuous annular locking ridge 32a. When the locking means is constituted by the annular locking projection 32a, the entire annular locking projection 32a serves as the main portion 34a of the locking means, and a plurality of lightening portions 44a are formed on the lower surface 42a of the main portion 34a. are circumferentially spaced apart.

Although the preferred embodiments of the container lid of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not limited to the above embodiments, and further modifications are possible within the scope of the present invention. For example, in the illustrated embodiment, on the upper surface of the locking means, the inner diameter gradually increases upward and extends substantially horizontally together with the fitting upper surface connected to the inner peripheral surface of the tamper-evident skirt. Although the engaging upper surface was also provided, the engaging upper surface may be omitted and the entire upper surface of the engaging means may be used as the fitting upper surface. Also, the lower surface of the locking means may be substantially horizontal. In addition, although the shape of the lightening portion 44 was rectangular in the embodiment and the modified example, it may have a curvilinear shape, such as connecting the lower ends of the residual portion in an arc shape (arch shape) when viewed in the circumferential direction. It can be without meat.

2: Container lid 4: Top wall 6: Skirt wall 14: Breaking line 16: Skirt main part 18: Tamper evident hem part 20: Slit 22: Bridge part 26: Female screw thread 32: Locking protrusion (locking means )
34: Main portion (of the locking projection) 40: Fitting upper surface (of the main portion of the locking projection) 42: Lower surface (of the main portion of the locking projection) 44: Lightening portion

Claims (5)

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 formed in the main part of the skirt above the breaking line and the tamper-evident bottom part below the breaking line. A female thread is formed on the inner peripheral surface of the skirt main portion, and a plurality of radially inwardly protruding and circumferentially extending threads are formed on the inner peripheral surface of the tamper-evident skirt portion. A locking means comprising a locking projection or an annular locking ridge projecting radially inwardly and extending continuously in the circumferential direction is provided, and the inner peripheral edge of the main portion of the locking means is In the synthetic resin container lid that is continuous in the circumferential direction along the inner peripheral surface of the tamper-evident hem,
A container lid made of synthetic resin, characterized in that a plurality of lightening portions are formed at intervals in the circumferential direction on the lower surface of the main portion. 2. The synthetic resin container lid according to claim 1, wherein the inner peripheral edge of the main portion continues in the circumferential direction in parallel with the inner peripheral surface of the tamper-evident bottom portion. 3. The synthetic resin container lid according to claim 1, wherein the lower surface of the main portion is downwardly inclined radially outward and connected to the inner peripheral surface of the tamper-evident skirt portion. When the locking means is composed of a plurality of locking projections, the inner peripheral edges of the ends of the locking projections on both sides in the circumferential direction are circumferentially outward from the circumferential ends of the inner peripheral edges of the main portion. 4. The synthetic resin container lid according to any one of claims 1 to 3, which is connected to the inner peripheral surface of the tamper-evident hem portion while sloping radially outward. 5. The synthetic resin container according to claim 4, wherein the lower surface of the end portion is provided with a reinforcing portion whose inner diameter gradually increases downward and is connected to the inner peripheral surface of the tamper-evident skirt portion. lid.

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