Synthetic resin container closure, and combination thereof with container
A deformable contact piece in the container lid addresses the issue of overtightening by absorbing force, ensuring easy opening and effective sealing despite positive pressure.
Patent Information
- Application Number
- JP2024095833
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-06-13
- Publication Date
- 2025-12-25
AI Technical Summary
Existing synthetic resin container lids tend to be overtightened, leading to increased initial opening torque due to the deformation of the top wall under positive pressure, which is not adequately addressed by existing designs.
The container lid features a deformable contact piece extending radially downward, allowing it to absorb and reduce the force exerted on the neck surface, preventing excessive torque buildup.
The deformable design prevents excessive initial opening torque even when the lid is overtightened, maintaining effective sealing and ease of opening.
Smart Images
Figure 2025187216000001_ABST
Abstract
Description
[Technical Field]
[0001] The present invention relates to a synthetic resin container lid and a combination of the lid and a container. [Background technology]
[0002] For example, as shown in Patent Document 1 below, a synthetic resin container lid has already been widely used, which includes a top wall and a cylindrical skirt wall hanging down from the periphery of the top wall, and has a cylindrical inner seal wall and a cylindrical outer seal wall extending downward from the outer peripheral edge of the lower surface of the top wall, a contact piece positioned radially between the inner seal wall and the outer seal wall, and an internal thread formed on the inner peripheral surface of the skirt wall. Such a container lid can be applied to the mouth and neck of a container in which the contents contained therein, such as a carbonated beverage, create a positive pressure (pressure greater than atmospheric pressure) inside. A male thread is formed on the outer peripheral surface of the mouth and neck of the container, and when the female thread of the container lid is threaded onto the male thread of the mouth and neck and the container lid is attached to the mouth and neck, the outer peripheral surface of the inner sealing wall of the container lid is brought into tight contact with the inner peripheral surface of the mouth and neck, and the inner peripheral surface of the outer sealing wall of the container lid is brought into tight contact with the outer peripheral surface of the mouth and neck, and the abutment piece of the container lid is brought into contact with the top surface of the mouth and neck, thus sealing the mouth and neck of the container.
[0003] In the container lid disclosed in Patent Document 1 below, when the lid is attached to the mouth and neck portion, the abutment piece abuts against the top surface of the mouth and neck portion. That is, the top surface of the mouth and neck portion abuts locally against the underside of the top wall of the container lid. Therefore, the area of contact between the top surface of the mouth and neck portion and the underside of the top wall is reduced compared to when the abutment piece is not present and the entire top surface of the mouth and neck portion abuts against the underside of the top wall of the container lid. This reduces the frictional force generated between them, and therefore reduces the initial torque required to open the mouth and neck portion when it is rotated in the opening direction to open it. [Prior art documents] [Patent documents]
[0004] [Patent Document 1] Patent No. 5891002 Summary of the Invention [Problem to be solved by the invention]
[0005] However, according to the research of the present inventors, when filling a container with contents, the container lid tends to be overtightened, i.e., exceeding the required design seaming angle, onto the neck of the container to prevent the contents from leaking from the neck of the container. When the container lid is overtightened onto the neck of the container, the contact piece is pressed with a strong force by the top surface of the neck, and the contact piece is fixed to the top surface of the neck, increasing the initial torque for opening.
[0006] Here, when the contents, such as a carbonated beverage, create positive pressure inside the container, the positive pressure causes the top wall of the container lid to deform upward into a dome shape, reducing the adhesive force between the abutment piece and the top surface of the neck portion, and it is thought that the increase in the initial opening torque is suppressed to some extent. However, this depends on the magnitude of the pressure generated by the contents, i.e., the gas volume. In other words, when the gas volume of the contents is large, the top wall is deformed relatively greatly, which significantly reduces the adhesive force between the abutment piece and the top surface of the neck portion, and the initial opening torque is significantly reduced. On the other hand, when the gas volume of the contents is relatively small, the amount of deformation of the top wall is small, so the reduction in the adhesive force between the abutment piece and the top surface of the neck portion is also small, and therefore the reduction in the initial opening torque is also slight.
[0007] The present invention was made in consideration of the above facts, and its main technical objective is to provide a new and improved synthetic resin container lid and a combination thereof with a container, which prevents the initial opening torque from increasing excessively even if the lid is excessively tightened when attached to the mouth and neck. [Means for solving the problem]
[0008] As a result of extensive research, the inventors have found that the above-mentioned main technical problem can be solved by extending the contact piece downward at an inclination in the radial direction to make it deformable.
[0009] That is, according to the present invention, a synthetic resin container lid that solves the above-mentioned main technical problems is provided, which comprises a top wall and a cylindrical skirt wall hanging down from the periphery of the top wall, and has a cylindrical inner seal wall and a cylindrical outer seal wall extending downward from the outer peripheral edge of the lower surface of the top wall, as well as a contact piece located radially between the inner seal wall and the outer seal wall, and a female thread formed on the inner surface of the skirt wall, and the contact piece extends downward at an inclination in the radial direction and is freely deformable.
[0010] Preferably, the contact pieces are disposed spaced apart from the inner seal wall and the outer seal wall. It is preferable that the contact pieces extend continuously over the entire circumferential direction. It is preferable that the contact pieces extend downward and inclined radially outward. In this case, the vertical cross-sectional shape of the inner peripheral surface of the contact piece is preferably a convex arc. Furthermore, it is preferable that the vertical cross-sectional shape of the outer peripheral surface of the contact piece is a straight line or a concave arc. Furthermore, a preferred combination is a combination of the above-mentioned synthetic resin container lid and a container to which the container lid is applied, in which the top surface of the mouth and neck portion of the container has a flat, annular central portion, and a male thread is formed on the outer peripheral surface of the mouth and neck portion, and when the female thread is threaded onto the male thread and the container lid is attached to the mouth and neck portion, the outer peripheral surface of the inner sealing wall is brought into close contact with the inner peripheral surface of the mouth and neck portion and the inner peripheral surface of the outer sealing wall is brought into close contact with the outer peripheral surface of the mouth and neck portion, and the contact piece abuts against the central portion of the top surface of the mouth and neck portion and is deformed. [Effects of the Invention]
[0011] In the container lid of the present invention, the abutment piece is deformable by extending at an inclination in the radial direction downward, so that when it is attached to the mouth and neck of the container, the abutment piece abuts against the top surface of the mouth and neck and is deformed, thereby absorbing and reducing the force with which the abutment piece presses against the top surface of the mouth and neck. Therefore, with the container lid of the present invention, even if the container is over-tightened when attached to the mouth and neck, an excessive increase in the initial opening torque is prevented. [Brief explanation of the drawings]
[0012] [Figure 1] 1 is a front view, partly in cross section, showing a state in which a container lid constructed according to the present invention is attached to the mouth and neck portion of a container. [Figure 2] 2 is a partially enlarged cross-sectional view showing the process of attaching the container lid shown in FIG. 1 to the mouth and neck of the container. [Figure 3] 2 is an enlarged cross-sectional view of a portion of the container after the container lid shown in FIG. 1 has been attached to the mouth and neck portion of the container and the inside of the container is under positive pressure. DETAILED DESCRIPTION OF THE INVENTION
[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a more detailed description will be given with reference to the accompanying drawings showing preferred embodiments of a container lid and a combination thereof constructed according to the present invention.
[0014] 1, a container lid constructed in accordance with the present invention, generally designated by the numeral 2, can be compression molded or injection molded from a suitable synthetic resin such as polyethylene or polypropylene. The container lid 2 has a circular top wall 4 and a cylindrical skirt wall 6 depending from the outer periphery of the top wall 4.
[0015] The top wall 4 is divided into a relatively thin circular central portion 8 and a relatively thick annular outer peripheral edge portion 10. A circular recess 12 is formed on the outer peripheral edge portion of the lower surface of the central portion 8. A cylindrical inner seal wall 14 extending downward is formed on the inner peripheral edge of the lower surface of the outer peripheral edge portion 10. The base end edge of the inner peripheral surface of the inner seal wall 14 is connected to the outer peripheral edge of the central portion 8. The vertical cross-sectional shape of the outer peripheral surface of the inner seal wall 14 is convex and bulges outward in the radial direction, while the vertical cross-sectional shape of the inner peripheral surface is approximately linear. A cylindrical outer seal wall 16 is formed on the lower surface of the outer peripheral edge portion 10 outside the inner seal wall 14. The vertical length of the outer seal wall 16 is shorter than the vertical length of the inner seal wall 14, and the entire outer seal wall 16 is inclined radially inward as it faces downward.
[0016] 2(a) in conjunction with FIG. 1, an abutment piece 18 is also formed on the underside of the outer peripheral edge portion 10, radially between the inner seal wall 14 and the outer seal wall 16. The abutment piece 18 is disposed at a distance from the inner seal wall 14 and the outer seal wall 16. This minimizes the influence of the abutment piece 18 on the formation of the inner seal wall 14 and the outer seal wall 16 within the mold when molding the container lid 2. Furthermore, when the container lid 2 is released from the mold, the abutment piece 18 is released from the mold smoothly enough, thus achieving the desired shape of the abutment piece 18. The lower end of the abutment piece 18 is located above the lower end of the outer seal wall 16, and therefore above the lower end of the inner seal wall 14, when viewed from the vertical direction. In a container lid constructed according to the present invention, it is important that the abutment piece 18 extends downward at an inclination in the radial direction and is therefore deformable. In the illustrated embodiment, the abutment piece 18 extends downward, inclined radially outward, and continuously around the entire circumference. As shown in FIG. 2(a), the vertical cross section of the inner peripheral surface 20 of the abutment piece 18 is convex arc-shaped, and the vertical cross section of the outer peripheral surface 22 is linear. This shape of the abutment piece 18 further improves the releasability of the abutment piece 18 from the mold. If desired, the vertical cross section of the outer peripheral surface 22 of the abutment piece 18 may be concave arc-shaped.
[0017] Continuing the explanation with reference to Figure 1, in the illustrated embodiment, a circumferential breakable line 24 extending in the circumferential direction is disposed on the lower part of the skirt wall 6, and the skirt wall 6 is divided into a main part 26 above the circumferential breakable line 24 and a tamper-evident skirt 28 below the circumferential breakable line 24. The tamper-evident skirt 28 is composed of a plurality of circumferentially extending slits 30 spaced equally apart in the circumferential direction and a plurality of breakable bridges 32 remaining between each pair of circumferentially adjacent slits 30, and the tamper-evident skirt 28 is connected to the main part 26 by the plurality of breakable bridges 32.
[0018] The outer peripheral surface of the main portion 26 of the skirt wall 6 is formed with so-called knurls (repeated uneven shapes) 34 to prevent slippage of fingers placed thereon. The inner peripheral surface of the main portion 26 of the skirt wall 6 is formed with a female thread 36. The inner peripheral surface of the tamper-evident bottom portion 28 is formed with a locking ridge 38 extending in the circumferential direction. Although not necessarily shown in the drawings, a plurality of locking ridges 38 are formed at intervals in the circumferential direction.
[0019] FIG. 1 also shows a container neck portion 100 to which the above-described container closure 2 is applied. The container neck portion 100, which can be formed from a suitable synthetic resin such as polyethylene terephthalate or glass, has an overall cylindrical shape. Referring to FIG. 2(a) in addition to FIG. 1, the longitudinal cross-sectional shape of the top surface of the neck portion 100 has a flat central portion 102 and a pair of arcuate end portions 104 located on both radial sides of this central portion 102. Therefore, the central portion 102 of the top surface of the neck portion 100 has a flat annular shape. The outer peripheral surface of the neck portion 100 is formed with a male thread 106, a locking jaw portion 108 located below the male thread 106, and a support ring 110 located further below the locking jaw portion 108.
[0020] A typical example of how the above-mentioned container lid 2 is used will be described with reference to Figures 1 and 2. First, a required amount of content, such as a carbonated beverage, is filled into the container. Next, the container lid 2 is fitted onto the mouth and neck portion 100 of the container and rotated in the closing direction, i.e., clockwise as viewed from above in Figure 1, thereby threading the male thread 106 of the mouth and neck portion 100 onto the female thread 36 of the container lid 2. As the male thread 106 and the female thread 36 thread together, the container lid 2 is gradually lowered. As a result, the inner seal wall 14 disposed on the top wall 4 of the container lid 2 enters the mouth and neck portion 100 and is brought into tight contact with the inner circumferential surface of the mouth and neck portion 100, and the outer seal wall 16 disposed on the top wall 4 is brought into tight contact with the outer circumferential surface of the mouth and neck portion 100. Furthermore, the locking protrusion 38 disposed on the tamper-evident skirt 28 elastically overcomes the locking jaw 108 of the neck portion 100 and is positioned below it. When the container lid 2 is lowered to the position shown in Figure 2(a), the lower end of the inner peripheral surface 20 of the abutting piece 18 disposed on the top wall 4 of the container lid 2 abuts against the central portion 102 of the top surface of the neck portion 100. When the container lid 2 is further lowered from the position shown in Figure 2(a), the abutting piece 18 is pressed and deformed by the central portion 102 of the top surface of the neck portion 100, as shown in Figure 2(b), and then prevents further lowering of the container lid 2. The abutting piece 18 is preferably plastically deformed, but may also be elastically deformed. In the state shown in Figure 2(b), the inner seal wall 14 of the container lid 2 is tightly fitted to the inner surface of the mouth and neck portion 100, and the outer seal wall 16 of the container lid 2 is tightly fitted to the outer surface of the mouth and neck portion 100, so that the mouth and neck portion 100 is sealed.
[0021] In the container closure of the present invention, the abutment piece 18 is deformable by extending at an inclination in the radial direction downward. Therefore, when the abutment piece 18 is attached to the container neck portion 100, the abutment piece 18 abuts against the top surface of the neck portion 100, more specifically, the central portion 102 thereof, and is deformed. This absorbs and reduces the force with which the abutment piece 18 presses against the top surface of the neck portion 100. Therefore, with the container closure of the present invention, even if the closure is excessively tightened when attached to the neck portion 100, an excessive increase in the initial opening torque is prevented. In the illustrated embodiment, the outer peripheral surface 22 of the abutment piece 18 is linear. Therefore, when the abutment piece 18 abuts against the top surface of the neck portion 100 and is deformed, excessive stress is not applied to the base end of the abutment piece 18, and the abutment piece 18 is prevented from breaking. Furthermore, since the inner surface 20 of the abutment piece 18 is convex arc-shaped, when the abutment piece 18 is brought into contact with the top surface of the mouth and neck portion 100, the force that the abutment piece 18 receives from the top surface of the mouth and neck portion 100 is dispersed, which also prevents the abutment piece 18 from breaking.
[0022] In the illustrated embodiment, the contents contained in the container are a carbonated beverage, and therefore, when the neck portion 100 is sealed, a positive pressure is created inside the container. As a result, the top wall 4 is slightly deformed upward into a dome shape, as shown in FIG. 3 . This causes the abutment piece 18 to be spaced slightly upward from the top surface of the neck portion 100. This is because, in the illustrated embodiment, the abutment piece 18 is plastically deformed. As can be clearly understood by referring to FIG. 3 , when the top wall 4 is deformed as described above, the inner seal wall 14 is maintained in intimate contact with the inner circumferential surface of the neck portion 100 without being spaced apart from the inner circumferential surface, and the outer seal wall 16 is brought into even more firm and intimate contact with the outer circumferential surface of the neck portion 100. Therefore, the sealing of the neck portion 100 is not impaired due to the deformation of the top wall 4.
[0023] When the contents of the container, i.e., the carbonated beverage, are to be consumed, the container lid 2 is rotated in the opening direction, i.e., counterclockwise in Figure 1, to gradually disengage the male thread 106 from the female thread 36. When starting to rotate the container lid 2 in the opening direction, the abutment piece 18 is separated from the top surface of the neck portion 100, so that excessive initial torque is not applied to open the container. As the male thread 106 and the female thread 36 are disengaged, the container lid 2 is raised, but the tamper-evident skirt 28 is prevented from rising because the locking projection 38 is locked by the locking jaw 108 of the neck portion 100. Thus, stress is generated in the bridging portion 32 of the circumferential breakable line 24, causing the bridging portion 32 to break, and the tamper-evident skirt 28 is separated from the main portion 26 of the skirt wall 6. Thereafter, as the container lid 2 is rotated in the opening direction, the main portion 26 of the skirt wall 6 together with the top wall 4 rises and is separated from the neck portion 100, but the tamper-evident skirt portion 28 remains in the neck portion 100. In this way, the neck portion 100 is opened.
[0024] While the container lid constructed according to the present invention and its combination with a container have been described in detail above using the example of filling a container with a cooled carbonated beverage, the container lid constructed according to the present invention is not limited to such applications and can also be advantageously used in cases where, for example, nitrogen gas is sealed in the neck of the container to create a positive pressure inside the container in order to prevent oxidation and deterioration of the contents. Furthermore, the container lid constructed according to the present invention is not only applicable to containers with a positive internal pressure, but can also be used with containers with an internal pressure equal to atmospheric pressure or a negative pressure.
[0025] Although the container lid and the combination thereof constructed in accordance with the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited to the above-described embodiment, and appropriate modifications and variations are possible within the scope of the present invention. For example, in the illustrated embodiment, the abutment piece extends continuously around the entire circumference, but multiple abutment pieces may be arranged at intervals around the circumference. Furthermore, in the illustrated embodiment, the abutment piece extends downward at an inclination radially outward, but may extend downward at an inclination radially inward. [Explanation of symbols]
[0026] 2: Container lid 4: Top wall 6: Skirt wall 14: Inner seal wall 16: Outer seal wall 18: Contact piece 36:Female thread 100: Container neck 102: Center (of the top surface) 104: (Top) edge 106: Male screw
Claims
1. The container has a top wall and a cylindrical skirt wall that hangs down from the periphery of the top wall, a cylindrical inner seal wall and a cylindrical outer seal wall extending downward from the outer peripheral edge of the lower surface of the top wall, and a contact piece located between the inner seal wall and the outer seal wall in the radial direction, and a female thread is formed on the inner peripheral surface of the skirt wall; The synthetic resin container lid is characterized in that the contact piece extends downward at an inclination in the radial direction and is deformable.
2. 2. The synthetic resin container lid according to claim 1, wherein the contact piece is disposed spaced apart from the inner seal wall and the outer seal wall.
3. 2. The synthetic resin container lid according to claim 1, wherein said contact piece extends continuously over the entire circumferential direction.
4. 2. The synthetic resin container closure according to claim 1, wherein said contact piece extends downward at an inclination radially outward.
5. 5. The synthetic resin container closure according to claim 4, wherein the vertical cross section of the inner peripheral surface of said contact piece is convex arc-shaped.
6. 6. A synthetic resin container lid according to claim 4, wherein the vertical cross section of the outer peripheral surface of said contact piece is linear or concave arc-shaped.
7. A combination of the synthetic resin container lid according to claim 1 and a container to which the container lid is applied, The top surface of the neck of the container has a flat circular central portion, and a male thread is formed on the outer circumferential surface of the neck, When the female screw thread is threaded onto the male screw thread and the container lid is attached to the neck portion, the outer peripheral surface of the inner seal wall is brought into close contact with the inner peripheral surface of the neck portion and the inner peripheral surface of the outer seal wall is brought into close contact with the outer peripheral surface of the neck portion, and the contact piece abuts against the center of the top surface of the neck portion and is deformed.
Citation Information
Patent Citations
Gasifying method of heavy oil by fluid catalytic partial oxidation
JP1983091002A