Container lid made of synthetic resin

Abstract

A synthetic resin container lid includes: a main body having a top wall and a cylindrical skirt wall hanging down from the periphery of the top wall, wherein an internal thread is formed on the inner peripheral surface of the skirt wall; and a cylindrical anti-tampering skirt portion connected to the skirt wall of the main body through a plurality of breakable bridge portions arranged at circumferential intervals, wherein an engaging mechanism for engaging with the engaging claw portion is provided on the inner peripheral surface of the anti-tampering skirt portion. A protruding piece is provided on the skirt wall of the main body with a downward protruding piece. A non-breaking connecting piece is provided to connect the skirt wall of the main body to the anti-tampering skirt portion and allow the main body to move upward relative to the anti-tampering skirt portion. In at least the angular region where the protruding piece exists, an extension portion is formed on the engaging piece serving as the engaging mechanism, and the extension portion is located between the engaging claw portion of the mouth neck portion and the anti-tampering skirt portion in a state where the synthetic resin container lid is mounted on the mouth neck portion. A raised portion is formed on the outer surface of the protruding piece.

Description

Technical Field

[0001] The present invention relates to a synthetic resin container lid having an anti-tampering feature, which is applicable to a container having an external thread formed on the outer peripheral surface of the mouth neck portion and an engaging claw portion located below the external thread, and even after the mouth neck portion of the container is unsealed, the container lid does not entirely separate from the mouth neck portion of the container. Background Art

[0002] The following Patent Documents 1 to 3 disclose a synthetic resin container lid applicable to a container having an external thread formed on the outer peripheral surface of the mouth neck portion and an engaging claw portion located below the external thread. The synthetic resin container lid includes: a main body having a top wall and a cylindrical skirt wall hanging down from the periphery of the top wall, an internal thread being formed on the inner peripheral surface of the skirt wall for screwing with the external thread of the mouth neck portion; a cylindrical anti-tampering skirt portion connected to the skirt wall of the main body through a plurality of breakable bridge portions arranged at intervals in the circumferential direction, an engaging mechanism for engaging with the engaging claw portion being provided on the inner peripheral surface of the cylindrical anti-tampering skirt portion. The engaging mechanism is composed of a plurality of engaging pieces arranged at intervals in the circumferential direction and each of which extends upward and radially inward from the base end connected to the anti-tampering skirt portion, or is composed of a single engaging piece extending continuously in the circumferential direction and extending upward and radially inward from the base end connected to the anti-tampering skirt portion. A protruding piece protruding downward is provided on the skirt wall of the main body. On one side or both sides in the circumferential direction of the protruding piece, a non-breakable connecting piece for connecting the skirt wall of the main body to the anti-tampering skirt portion and allowing the main body to move upward relative to the anti-tampering skirt portion is provided.

[0003] When the container lid as described above is installed on the mouth-neck portion of the container to seal the mouth-neck portion, the container lid is fitted onto the mouth-neck portion and rotated in the closing direction so that the internal thread of the container lid engages with the external thread of the mouth-neck portion. As the engagement progresses, the container lid descends relative to the mouth-neck portion, and the engaging mechanism formed on the anti-tampering skirt elastically passes over the engaging claw portion of the mouth-neck portion to be located below the mouth-neck portion. When unsealing the mouth-neck portion, the container lid is rotated in the opening direction to release the engagement between the external thread of the mouth-neck portion and the internal thread of the container lid. As the engagement is released, the main body of the container lid is allowed to rise relative to the mouth-neck portion. On the other hand, the anti-tampering skirt is prevented from rising because the engaging mechanism engages with the engaging claw portion of the mouth-neck portion. Therefore, the breakable bridge portion is stressed and breaks. After the breakable bridge portion breaks, the main body continues to rise and separates upward from the anti-tampering skirt. This causes the non-breakable connecting piece to deform, but the non-breakable connecting piece does not break, and the anti-tampering skirt continues to be installed on the mouth-neck portion. Therefore, even after the main body is detached from the mouth-neck portion, the main body continues to be connected to the anti-tampering skirt via the non-breakable connecting piece. Therefore, the main body is never separated from the mouth-neck portion of the container. After the main body of the container lid is detached from the mouth-neck portion, the main body of the container lid can pivot away from the mouth-neck portion around a predetermined portion of the non-breakable connecting piece. When the main body of the container lid pivots beyond a predetermined angle, the front end portion of the protruding piece formed on the skirt wall elastically passes over the engaging claw portion of the mouth-neck portion until it is located on the upper surface side of the engaging claw portion. Thereby, the main body is prevented from returning toward the mouth-neck portion and is held at a position spaced apart from the mouth-neck portion, so that the mouth-neck portion remains unsealed. When the front end portion of the protruding piece elastically passes over the engaging claw portion, a sound is generated due to the elastic deformation and elastic recovery of the protruding piece, allowing the consumer to be aware that the main body of the container lid has pivoted to the desired open position.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2010-18290

[0007] Patent Document 2: Japanese Patent Application Laid-Open No. 2012-76771

[0008] Patent Document 3: Japanese Patent Application Laid-Open No. 2014-31202 Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] In recent years, from the viewpoints of environmental issues and material cost reduction, there has been a demand for lightweight packaging containers. At the same time, there has also been a demand for thin-walled container lids with reduced axial dimensions. In this situation, the present inventor has noticed from experience that the above-mentioned conventional container lids have the following problems to be solved, especially in the case where the neck portion is relatively short axially and accordingly the axial dimension of the container lid is relatively small (in other words, the container lid has a relatively small height in the vertical direction). When pivoting the body detached from the neck portion away from the neck portion to unseal the neck portion, the front end portion of the protruding piece elastically crosses over the engaging claw portion of the neck portion until it is located above the engaging claw portion. At this time, due to the relatively small axial dimension of the container lid, the protruding piece has a relatively short extending length, and thus the amount of mutual interference between the protruding piece and the engaging claw portion becomes too small. This results in the following problems: (1) Once the front end portion of the protruding piece is located above the engaging claw portion, the front end of the protruding piece has a tendency to accidentally return to the position below the engaging claw portion, so that the body may not be held in the required open position; and (2) The sound generated when the protruding piece elastically crosses over the engaging claw portion is unsatisfactory, so that consumers often cannot realize that the body has been pivoted to the required open position.

[0011] To solve the above problems, the present inventor has proposed in the specification of Japanese Patent Application No. 2019-025644 to form an extension portion on the engaging piece at least in the angular region where the protruding piece exists. This extension portion is located between the engaging claw portion of the neck portion and the anti-tampering skirt portion of the neck portion in the state where the container lid is mounted on the neck portion. Therefore, even if the container lid has a relatively short length axially, once the body detached from the neck portion is pivoted to the required open position, it can be held in the required open position sufficiently reliably and a sound that can be heard by the user can be generated sufficiently reliably.

[0012] However, the synthetic resin container lid previously proposed by the present inventor is not completely satisfactory, and the following problems still remain. The body of the container lid is held in the required open position by the outer surface of the lower portion of the protruding piece contacting the outer surface of the upper portion of the extension portion at the required open position. In the case where the container lid is relatively short axially, the axial dimension of the protruding piece is also relatively small. Therefore, when the body is in the required open position, its pivoting angle with respect to the neck portion of the container is not large enough. As a result, when the user puts his / her mouth against the upper end portion of the neck portion of the container, the lower end of the skirt wall contacts the user's face, which makes the user feel uncomfortable. Further, due to the relatively small axial dimension of the protruding piece, the outer surface of the lower portion of the protruding piece cannot contact the outer surface of the upper portion of the extension portion sufficiently reliably, so that the body of the container lid may not be held in the required open position.

[0013] The present invention has been accomplished in view of the above facts. Its main technical challenge lies in further improving the synthetic resin container lid previously proposed by the present inventor, so as to ensure a sufficiently large pivoting angle of the main body relative to the mouth neck portion of the container when the main body is in the desired open position, and to hold the main body in the desired open position sufficiently reliably, even when the container lid is relatively short axially.

[0014] Means for Solving the Problem

[0015] As a result of further in-depth research, the present inventor has found that the aforementioned main technical challenge can be solved by forming a raised portion on the outer surface of the protruding piece. More specifically, when the main body rotates in the opening direction to unseal the mouth neck portion sealed with the container lid mounted thereon, the breakable bridge portion breaks, so that the main body moves up from the anti-tampering skirt portion. When the main body pivots relative to the anti-tampering skirt portion around a predetermined portion of the non-breakable connecting piece by more than a predetermined angle, the lower portion of the protruding piece elastically crosses over the extension portion until the raised portion of the protruding piece contacts the outer surface of the extension portion.

[0016] Furthermore, as a result of further in-depth research, the present inventor has found that the aforementioned main technical challenge can be solved by forming a mating interlocking mechanism on the outer surface of the extension portion and an interlocking mechanism formed on the outer surface of the protruding piece that interlocks with the mating interlocking mechanism. More specifically, when the main body rotates in the opening direction to unseal the mouth neck portion sealed with the container lid mounted thereon, the breakable bridge portion breaks, so that the main body moves up from the anti-tampering skirt portion. When the main body pivots relative to the anti-tampering skirt portion around a predetermined portion of the non-breakable connecting piece by more than a predetermined angle, the lower portion of the protruding piece elastically crosses over the extension portion until the interlocking mechanism of the protruding piece interlocks with the mating interlocking mechanism of the extension portion.

[0017] According to a first aspect of the present invention, there is provided a synthetic resin container lid adapted for use with a container having an external thread formed on the outer peripheral surface of a mouth neck portion and an engaging claw portion located below the external thread, the synthetic resin container lid comprising:

[0018] A main body having a top wall and a cylindrical skirt wall hanging down from the periphery of the top wall, wherein an internal thread adapted to be screwed with the external thread is formed on the inner peripheral surface of the skirt wall; and

[0019] A cylindrical anti-tampering skirt portion connected to the skirt wall of the main body by a plurality of breakable bridge portions arranged at circumferential intervals, wherein an engaging mechanism adapted to engage with the engaging claw portion is provided on the inner peripheral surface of the anti-tampering skirt portion;

[0020] The engaging mechanism is composed of a plurality of engaging pieces that are circumferentially spaced apart and extend upward and radially inward from the base end connected to the anti-tampering skirt, or is composed of an annular engaging piece that extends continuously in the circumferential direction and extends upward and radially inward from the base end connected to the anti-tampering skirt;

[0021] A protruding piece that protrudes downward is provided on the skirt wall of the main body; and

[0022] A non-breaking connecting piece is provided that connects the skirt wall of the main body to the anti-tampering skirt and allows the main body to move upward relative to the anti-tampering skirt;

[0023] Wherein, at least in the angular region where the protruding piece exists, an extension portion is formed on the engaging piece, and the extension portion is located between the engaging claw portion of the mouth neck portion and the anti-tampering skirt in a state where the synthetic resin container cap is installed on the mouth neck portion;

[0024] A raised portion, which is formed on the outer surface of the protruding piece; and

[0025] When the main body rotates in the opening direction to unseal the mouth neck portion sealed with the synthetic resin container cap installed thereon, the breakable bridge portion breaks, so that the main body moves upward from the anti-tampering skirt, and when the main body pivots relative to the anti-tampering skirt around a predetermined portion of the non-breaking connecting piece by more than a predetermined angle, the lower portion of the protruding piece elastically crosses over the extension portion until the raised portion of the protruding piece contacts the outer surface of the extension portion.

[0026] According to a second aspect of the present invention, there is provided a synthetic resin container cap suitable for a container having an external thread formed on the outer peripheral surface of a mouth neck portion and an engaging claw portion located below the external thread, the synthetic resin container cap comprising:

[0027] A main body having a top wall and a cylindrical skirt wall hanging down from the periphery of the top wall, wherein an internal thread that engages with the external thread is formed on the inner peripheral surface of the skirt wall; and

[0028] A cylindrical anti-tampering skirt is connected to the skirt wall of the main body through a plurality of breakable bridge portions arranged at intervals in the circumferential direction, wherein an engaging mechanism that engages with the engaging claw portion is provided on the inner peripheral surface of the anti-tampering skirt;

[0029] The engaging mechanism is composed of a plurality of engaging pieces that are circumferentially spaced apart and extend upward and radially inward from the base end connected to the anti-tampering skirt, or is composed of an annular engaging piece that extends continuously in the circumferential direction and extends upward and radially inward from the base end connected to the anti-tampering skirt;

[0030] A protruding piece that protrudes downward is provided on the skirt wall of the main body; and

[0031] There is a non-breaking connecting piece that connects the skirt wall of the main body to the anti-tampering skirt and allows the main body to move upward relative to the anti-tampering skirt;

[0032] Wherein, at least in the angular region where the protruding piece exists, an extension is formed on the engaging piece. The extension is located between the engaging claw portion of the mouth neck portion and the anti-tampering skirt when the synthetic resin container lid is installed on the mouth neck portion, and a mating interlocking mechanism is formed on the outer surface of the extension;

[0033] An interlocking mechanism that interlocks with the mating interlocking mechanism is formed on the outer surface of the protruding piece;

[0034] When the main body rotates in the opening direction to unseal the mouth neck portion sealed with the synthetic resin container lid installed thereon, the breakable bridge portion breaks, so that the main body moves upward from the anti-tampering skirt. And when the main body pivots relative to the anti-tampering skirt around a predetermined portion of the non-breaking connecting piece by more than a predetermined angle, the lower part of the protruding piece elastically crosses over the extension until the interlocking mechanism of the protruding piece interlocks with the mating interlocking mechanism of the extension.

[0035] Preferably, an engagement protrusion is formed on the inner surface of the engagement piece, and the engagement protrusion protrudes radially inwardly below the engagement claw portion when the synthetic resin container lid is installed on the mouth and neck. Advantageously, the extension portion is also formed in an area outside the angle area where the protruding piece exists. Suitably, the engagement mechanism is composed of a plurality of engagement pieces arranged at intervals in the circumferential direction and extending upward and radially inwardly from the base end connected to the anti-tampering skirt, and the extension portion is formed on the circumferential two sides of each of the engagement pieces. Preferably, the outer surface of the extension portion gradually protrudes radially outwardly in the upward direction, and then gradually retracts radially inwardly in the upward direction, and the portion on the outer surface of the extension portion that gradually protrudes radially outwardly in the upward direction is concave arc-shaped in the longitudinal section. Desirably, except for a specific area, an arc-shaped protrusion extending continuously in the circumferential direction is formed in the lower end portion of the outer peripheral surface of the skirt wall and the upper end portion of the outer peripheral surface of the anti-tampering skirt; and the radial protrusion amount of the protrusion corresponds to the radial protrusion amount of the protrusion. Suitably, a matching interlocking mechanism is formed on the outer surface of the extension, and an interlocking mechanism interlocking with the matching interlocking mechanism is formed on the raised portion of the protruding piece. Particularly suitably, the outer surface of the extension gradually protrudes radially outward in an upward direction and then gradually retracts radially inward in the upward direction; the boundary area between the portion gradually protruding radially outward in the upward direction and the portion gradually retracting radially inward in the upward direction serves as the matching interlocking mechanism; and at least one protrusion or groove extending in the circumferential direction is formed on the raised portion of the protruding piece to serve as the interlocking mechanism.

[0036] Effects of the Invention

[0037] In the synthetic resin container cap according to the first aspect of the present invention, the raised portion formed on the outer surface of the protruding piece is used to hold the main body in the desired open position by contacting the outer surface of the extension. Therefore, even if the container cap is relatively short in the axial direction, a large pivot angle of the main body relative to the mouth and neck of the container can be ensured when the main body is in the desired open position. Further, since the raised portion contacts the outer surface of the extension sufficiently reliably, the main body is sufficiently reliably held in the desired open position.

[0038] In the synthetic resin container cap according to the second aspect of the present invention, the interlocking mechanism formed on the outer surface of the protruding piece is used to hold the main body in the desired open position by interlocking with the matching interlocking mechanism formed on the outer surface of the extension. Therefore, even if the container cap is relatively short in the axial direction, the main body can be sufficiently reliably held in the desired open position. Further, a large pivot angle of the main body relative to the mouth and neck of the container can be ensured when the main body is in the desired open position. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a perspective view showing a preferred embodiment of a container lid constructed according to the present invention.

[0040] Figure 2 is Figure 1 a front view of the container lid shown in

[0041] Figure 3 is Figure 1 a front view in which a part of the container lid shown in

[0042] Figure 4 is Figure 1 a bottom view of the container lid shown in

[0043] Figure 5 is Figure 1 a right view in which a part of the container lid shown in

[0044] Figure 6 is Figure 1 a front view of the main body of the container lid in an intermediate state of the unsealing operation in which it rotates and rises in the opening direction to disengage from the mouth neck of the container.

[0045] Figure 7 is partially shown in cross-section Figure 1 a side view of the main body of the container lid shown in

[0046] Figure 8 is partially shown in cross-section Figure 1 a side view of the main body of the container lid shown in

[0047] Figure 9 is Figure 8 an enlarged view near the tab shown in

[0048] Figure 10 is similar to Figure 9 an enlarged view showing another preferred embodiment of a container lid constructed according to the present invention.

[0049] Explanation of Reference Numerals

[0050] 2: Container lid; 4: Main body; 6: Tamper-evident skirt; 8: Top wall; 10: Skirt wall; 18: Internal thread; 22: Engaging mechanism; 24a - 24i: Engaging piece; 26: Extension; 34: Tab; 35: Ridge; 37a - 37b: Protrusion (engaging mechanism); 38a: Non-breaking connecting piece; 38b: Non-breaking connecting piece; 48: Breakable bridging portion; 50: Mouth neck; 52: External thread; 54: Engaging claw portion. Detailed Description of the Invention

[0051] Preferred embodiments of a synthetic resin container lid according to the present invention will now be described in further detail with reference to the accompanying drawings.

[0052] Reference Figures 1 to 4 , which shows a preferred embodiment of a synthetic resin container lid according to the present invention, the synthetic resin container lid as a whole denoted by reference numeral 2 can be advantageously integrally formed by injection molding or compression molding from a suitable synthetic resin such as polyethylene or polypropylene. The container lid 2 includes a main body 4 and a tamper-evident skirt 6. The main body 4 has a circular top wall 8 and a cylindrical skirt wall 10 hanging down from the peripheral edge of the top wall 8. Two sealing protrusions, namely an inner annular protrusion 12 and an outer annular protrusion 14, are formed on the outer peripheral edge portion of the inner surface of the top wall 8. A deformation prevention mechanism 15 is provided in the central region of the inner surface of the top wall 8. The deformation prevention mechanism 15 is composed of a protrusion 15a protruding downward from the center of the inner surface of the top wall 8, a plurality of ribs (eight ribs in the illustrated embodiment) 15b radially extending from the outer peripheral surface of the protrusion 15a, and an annular surface protrusion 15c, and the inner surface of the annular surface protrusion 15c is connected to the radially outer ends of the ribs 15b. The presence of the deformation prevention mechanism 15 helps to increase the stiffness of the top wall 8. Therefore, even when there is a positive pressure inside the container by using, for example, a carbonated beverage filling container and sealing the mouth neck portion of the container with the container lid 2, deformation of the top wall 8 can be prevented. Concavo-convex portions 16 for preventing finger slipping acting thereon are repeatedly formed in the middle portion in the vertical direction of the outer peripheral surface of the skirt wall 10. Except for a specific region described later, an arcuate protrusion 17 is formed at the lower end portion of the outer peripheral surface of the skirt wall 10, and the protrusion 17 continuously extends in the circumferential direction along the lower edge of the skirt wall 10. The radially outer protruding amount of the protrusion 17 will be described later. An internal thread 18 is formed on the inner peripheral surface of the skirt wall 10. Notches 20 are formed at circumferential intervals on the internal thread 18.

[0053] The anti-tampering skirt portion 6 is integrally tubular and is connected to the skirt wall 10 of the main body 4 via a breakable bridge portion and a pair of non-breakable connecting pieces, which will be described later. At the upper end portion of the outer peripheral surface of the anti-tampering skirt portion 6, a protrusion 21 is continuously formed along the circumferential direction of the upper edge of the anti-tampering skirt portion 6, and the protrusion 21 corresponds to the protrusion 17 formed on the outer peripheral surface of the skirt wall 10. The radially outward protruding amount of the protrusion 21 will be described later. A engaging mechanism 22 is provided on the inner peripheral surface of the anti-tampering skirt portion 6. In the illustrated embodiment, the engaging mechanism 22 is composed of nine arc-shaped engaging pieces 24a to 24i formed at circumferential intervals. Each of the arc-shaped engaging pieces 24a to 24i extends axially upward and radially inward from the base end connected to the inner peripheral surface of the anti-tampering skirt portion 6. Although in the illustrated embodiment, the engaging mechanism 22 is constituted by nine arc-shaped engaging pieces 24a to 24i arranged at circumferential intervals, if necessary, the engaging mechanism 22 may be composed of an annular engaging piece that extends continuously in the circumferential direction and extends axially upward and radially inward from the base end connected to the inner peripheral surface of the anti-tampering skirt portion 6.

[0054] In the container lid 2 configured according to the present invention, an extension portion 26 extending from the front end of each of the engaging pieces 24a to 24i is formed at least in the region where the following protruding piece 34 is formed. In the illustrated embodiment, two rectangular extension portions 26 are formed to extend from two side portions in the circumferential direction of each of the engaging pieces 24a to 24i. By referring to Figure 9 and Figure 3 and Figure 4 it can be clearly understood that preferably, the outer surface of each of the extension portions 26 gradually protrudes radially outward in the upward direction and then gradually retracts radially inward in the upward direction. Preferably, the portion 26a that gradually protrudes radially outward in the upward direction is concave arc-shaped in the longitudinal section. The portion 26b that gradually retracts radially inward in the upward direction may have a frustum shape. The inner side surface of each of the extension portions 26 may be flat. Desirably, engaging protrusions 28 that protrude radially inward are formed on the inner surface of the main portion of each of the engaging pieces 24a to 24i, that is, the portion other than the extension portion 26. Appropriately, the engaging protrusions 28 further gradually protrude in the upward direction, and the upper surface thereof extends substantially horizontally. The engaging protrusions 28 are formed at the circumferential central portion of each of the engaging pieces 24a to 24i, that is, the region where the extension portion 26 does not exist. If desired, the engaging protrusions 28 may be formed over the entire circumferential length of each of the engaging pieces 24a to 24i.

[0055] Further referring to Figures 2 to 4, in a specific area indicated by reference numeral 30, the lower edge of the skirt wall 10 of the main body 4 (connected to the following projection piece 34) is displaced to be higher than the lower edge of the remaining area, while the upper edge of the anti-tampering skirt 6 (relative to the lower edge of the following projection piece 34) is displaced to be lower than the upper edge of the remaining area. Thus, a horizontally elongated opening 32 is formed between the skirt wall 10 and the anti-tampering skirt 6 in the front view. In the circumferential central portion of the opening 32, a substantially rectangular projection piece 34 protruding downward from its lower end is formed on the skirt wall 10. By referring to Figure 9 and Figure 2 it can be clearly understood that the projection piece 34 extends substantially vertically downward. It is important for the container lid 2 constructed according to the present invention that a raised portion 35 is formed on the outer surface of the projection piece 34. By referring to Figure 1 and Figure 5 it can be understood that the raised portion 35 is formed over the entire circumferential area of the lower half of the outer surface of the projection piece 34. If desired, the raised portion 35 can be formed over the entire vertical area of the outer surface of the projection piece 34. The raised portion 35 is substantially rectangular in cross-section, and its radially protruding amount corresponds to the radially protruding amounts of the protrusions 17 and 21 respectively formed on the outer peripheral surfaces of the skirt wall 10 and the anti-tampering skirt 6. In the illustrated embodiment, the radially protruding amounts of the raised portion 35, the protrusion 17, and the protrusion 21 are substantially the same. Thus, during the conveyance of the container lid 2 by itself or together with a container mounted to its neck portion, it is possible to prevent certain components from getting stuck at the circumferential end faces of the raised portion 35 as much as possible. Further, the upper end of the raised portion 35 and the upper end of the protrusion 17 are substantially at the same height when viewed vertically.

[0056] As Figure 2 and Figure 3 clearly shown, in the specific area 30, a pair of non-breaking connection pieces 38a and 38b are provided adjacent to the circumferential sides of the projection piece 34. The non-breaking connection piece 38a in the illustrated embodiment is composed of an upper end portion 40a connected to the lower edge of the skirt wall 10, a first inclined portion 42a that extends substantially horizontally toward the circumferential side (to the right side in Figure 2 and Figure 3 ) adjacent to the upper end portion 40a, an intermediate portion 44a, and a second inclined portion 46a that is adjacent to the intermediate portion 44a and extends substantially horizontally along the circumferential side (to the left side in Figure 2 and Figure 3 ) below the first inclined portion 42a and is connected to the anti-tampering skirt 6. Similarly, the non-breaking connection piece 38b is composed of an upper end portion 40b connected to the lower edge of the skirt wall 10, a first inclined portion 42b that extends substantially horizontally toward the circumferential side ( Figure 2 and Figure 3 to the left side in Figure 2 andFigure 3 extends substantially horizontally to the right and is connected to the second inclined portion 46b of the anti-tampering skirt 6. If desired, the first inclined portion 42a and the second inclined portion 46a of the non-breaking connecting piece 38a and the first inclined portion 42b and the second inclined portion 46b of the non-breaking connecting piece 38b may not be substantially horizontal, but may be inclined in a predetermined direction. By referring to Figure 2 it will be clearly understood that the non-breaking connecting piece 38a and the non-breaking connecting piece 38b are not axisymmetric with each other, and the circumferential dimensions of their constituent components are different (for the reasons, please refer to the description in the above-mentioned patent document 2).

[0057] In the region outside the specific region indicated by the reference numeral 30 (where there are the protruding piece 34 and a pair of non-breaking connecting pieces 38a and 38b), a plurality of breakable bridging portions 48 that connect the anti-tampering skirt 6 to the lower end connection of the skirt wall 10 of the main body 4 are arranged at circumferential intervals. In the illustrated embodiment, six narrow protrusions extending axially are formed at circumferential intervals on the inner surface of the skirt wall 10 and the inner surface of the anti-tampering skirt 6. The portion of each narrow protrusion located between the skirt wall 10 and the anti-tampering skirt 6 serves as the breakable bridging portion 48 (refer to Figure 3 ). If desired, the breakable bridging portion may also be provided in the region where there is a pair of non-breaking connecting pieces 38a and 38b. For example, the breakable bridging portion may be provided between the first inclined portions 42a, 42b and the skirt wall 10, or between the second inclined portions 46a, 46b and the anti-tampering skirt 6, or between the protruding piece 34 and the anti-tampering skirt 6.

[0058] Figure 5 The container neck portion 50 together with the container lid 2 is shown. The container neck portion 50, which can be formed of a suitable synthetic resin such as polyethylene terephthalate or glass, is integrally cylindrical and has an open upper surface. An external thread 52 and an engaging claw portion 54 located below the external thread 52 are formed on the outer peripheral surface of the neck portion 50.

[0059] When the container lid 2 is mounted on the neck portion 50 to seal the neck portion 50, the container lid 2 is fitted into the neck portion 50 and rotated in the closing direction (clockwise when viewed from above in Figure 5 ) so that the internal thread 18 of the container lid 2 is screwed with the external thread 52 of the neck portion 50. As the internal thread 18 is screwed with the external thread 52, the container lid 2 gradually descends relative to the neck portion 50. When the container lid 2 descends relative to the neck portion 50 to Figure 5After the state shown, the inner annular projection 12 and the outer annular projection 14 formed on the inner surface of the top wall 8 of the main body 4 of the container lid 2 are in close contact with the inner peripheral surface and the outer peripheral surface of the mouth neck portion 50, respectively, thereby sealing the mouth neck portion 50. In each of the engaging pieces 24a to 24i provided on the inner peripheral surface of the anti-tamper skirt portion 6 of the container lid 2, the main portion (i.e., the portion other than the extending portion 26) is elastically deformed to be located below the engaging claw portion 54 of the mouth neck portion 50, and at the same time, the upper surface of the engaging projection 28 formed on the inner surface faces the lower surface of the engaging claw portion 54. At the same time, the extending portion 26 of each of the engaging pieces 24a to 24i is located between the skirt wall 10 of the main body 4 and the engaging claw portion 54 of the mouth neck portion 50, specifically, between the inner peripheral surface of the skirt wall 10 and the outer peripheral surface of the engaging claw portion 54.

[0060] When unsealing the mouth neck portion 50, the container lid 2 is rotated in the opening direction (counterclockwise when viewed from above in Figure 5 ), so as to gradually release the screwing engagement between the internal thread 18 of the container lid 2 and the external thread 52 of the mouth neck portion 50. When the screwing engagement is gradually released, the main body 4 of the container lid 2 is allowed to rise as it rotates in the opening direction. On the other hand, since the upper surface of the engaging projection 28 of each of the engaging pieces 24a to 24i is engaged with the lower surface of the engaging claw portion 54 of the mouth neck portion 50, the anti-tamper skirt portion 6 is prevented from rising. As a result, a relatively large stress is applied to the breakable bridge portion 48 and it is broken. Then, the main body 4 of the container lid 2 rises as it rotates in the opening direction and gradually moves upwardly away from the anti-tamper skirt portion 6. By referring to Figure 6 it can be clearly understood that when the main body 4 gradually moves upwardly away from the anti-tamper skirt portion 6, the first inclined portion 42a of the non-breakable connecting piece 38a and the second inclined portion 46b of the non-breakable connecting piece 38b pivot clockwise about the intermediate portion 44a and the lower end of the second inclined portion 46b, respectively, that is, with the Figure 6 clockwise inclination in Figure 6 . However, the second inclined portion 46a of the non-breakable connecting piece 38a and the first inclined portion 42b of the non-breakable connecting piece 38b pivot counterclockwise about the lower end and the upper end, respectively, that is, with the Figure 7 counterclockwise inclination in Figure 6 . According to these movements, the inclination angles of the first inclined portions 42a and 42b and the second inclined portions 46a and 46b of the non-breakable connecting pieces 38a and 38b with respect to the vertical line gradually decrease. By referring to Figure 7 and Figure 6 it can be clearly understood that when the screwing engagement between the internal thread 18 of the container lid 2 and the external thread 54 of the mouth neck portion 50 is completely released, the main body 4 of the container lid 2 is detached from the mouth neck portion 50. However, since the main body 4 continues to be connected to the anti-tamper skirt portion 6 that remains mounted on the mouth neck portion 50 via the non-breakable connecting pieces 38a and 38b, the main body 4 does not move away from the mouth neck portion 50 of the container.

[0061] After the main body 4 of the container lid 2 is detached from the mouth neck portion 50, the main body 4 pivots away from the mouth neck portion 50 about the intermediate portions 44a and 44b of the non-breaking connection pieces 38a and 38b which serve as fulcrums ( Figure 7 in the clockwise direction in the figure). At this time, as Figure 7 shown, the extended end of the protruding piece 34 contacts one side portion of the engaging pieces 24a to 24i ( Figure 4 the left side of the engaging piece 24a and the right side of the engaging piece 24i in the figure), and the protruding piece 34 elastically deforms to rise along the outer surface of the engaging pieces 24a to 24i, and then along the extension portions 26 of the engaging pieces 24a to 24i ( Figure 4 the extension portion 26 on the left side of the engaging piece 24a and the extension portion 26 on the right side of the engaging piece 24i in the figure) on the concave arc-shaped portion 26a of the outer surface. Then, the lower portion of the protruding piece 34 elastically crosses over the concave arc-shaped portion 26a of the extension portion 26 until the raised portion 35 of the protruding piece 34 contacts Figure 8 and Figure 9 the outer surface of the extension portion 26 as shown in the figure. In this way, the main body 4 of the container lid 2 is held in the Figure 8 and Figure 9 open position shown in the figure. When the protruding piece 34 crosses over the arc-shaped portion 26a of the extension portion 26 and elastically returns, a sound is generated.

[0062] In the container lid 2 according to the present invention, the raised portion 35 formed on the outer surface of the protruding piece 34 is used to hold the main body 4 in the required open position by contacting the outer surface of the extension portion 26. Therefore, even if the container lid is relatively short in the axial direction, a large pivoting angle with respect to the mouth neck portion 50 of the container can be achieved when the main body 4 is in the required open position. Further, since the raised portion 35 contacts the outer surface of the extension portion 26 sufficiently reliably, the main body 4 is held in the required open position sufficiently reliably.

[0063] In the case of interrupting the intake of the contents, the main body 4 held in the Figure 8 position shown in the figure is forced to pivot in the direction approaching the mouth neck portion 50 ( Figure 8 the counterclockwise direction in the figure), and is again fitted into the mouth neck portion 50. Then, the container lid 2 is rotated in the closing direction to screw the internal thread 18 of the container lid 2 with the external thread 52 of the mouth neck portion 50. In this way, the container lid 2 is again in the Figure 5 position shown in the figure, whereby the mouth neck portion 50 can be temporarily sealed.

[0064] Figure 10Another preferred embodiment of a container lid constructed in accordance with the present invention is shown. According to this embodiment, the interlocking mechanism is provided on the raised portion 35 of the projecting piece 34, and the mating interlocking mechanism is provided on the outer surface of each of the engaging pieces 24a to 24i. More specifically, three projections 37a, 37b, and 37c extending circumferentially are formed to be vertically spaced apart over the entire width of the surface of the raised portion 35. These projections 37a, 37b, and 37c serve as the interlocking mechanism. At the same time, on the outer circumferential surface of each of the extensions 26 of the engaging pieces 24a to 24i, a junction region 26c is provided between a concave arc-shaped portion 26a that gradually projects radially outward in the upward direction and a portion 26b that gradually retracts radially inward in the upward direction. The junction region 26c serves as the mating interlocking mechanism. In Figure 10 the illustrated embodiment, when the lower portion of the projecting piece 34 passes over the concave arc-shaped portion 26a of the extension 26 until the main body pivots to the open position, the junction region 26c of each of the extensions 26 is locked between the projection 37a and the projection 37b (or between the projection 37b and the projection 37c) of the projecting piece 34. In this way, the main body 4 is reliably held in Figure 10 the illustrated open position.

[0065] In Figure 10 the illustrated embodiment, the interlocking mechanism is provided on the raised portion 35 of the projecting piece 34. If desired, the raised portion 35 may be omitted, and the interlocking mechanism may be provided on the outer surface of the projecting piece. Further, the interlocking mechanism consists of three projections 37a, 37b, and 37c formed to be vertically spaced apart. However, the interlocking mechanism may consist of one, two, or at least four projections, or may consist of one or more grooves extending circumferentially over the entire width of each of the extensions 26. Figure 10 The other components of the illustrated embodiment other than the above components may be substantially the same as those in Figures 1 to 9 the illustrated embodiment.

[0066] The preferred embodiments of the container lid constructed according to the present invention have been described in detail with reference to the accompanying drawings. The present invention is not limited to these embodiments and various modifications can be made without departing from the scope of the present invention. For example, in the illustrated embodiment, the extensions 26 are formed on both circumferential side portions of each of the engaging pieces 24a to 24i. However, one or at least three extensions may also be formed at appropriate positions (such as the central portion or a plurality of circumferentially spaced positions) of each of the engaging pieces 24a to 24i. If desired, one extension having a width substantially the same as the circumferential width of each of the engaging pieces 24a to 24i may also be formed. Further, in the illustrated embodiment, the extensions 26 are formed on the corresponding engaging pieces 24a to 24i. If desired, the extensions may be formed only on a plurality of specific engaging pieces or on the engaging pieces provided in the angular region where the protruding piece 34 is present. In the illustrated embodiment, there are two engaging pieces 24a and 24i in the angular region where the protruding piece 34 is present. However, only one engaging piece may be provided in the angular region where the protruding piece 34 is present and the extension may be formed only on this engaging piece. In the case of a circumferentially continuously extending annular engaging piece, one or more extensions may be formed in the angular region where the protruding piece 34 is present; a plurality of extensions spaced circumferentially not only in the angular region where the protruding piece 34 is present but also through the entire remaining angular region. Further, in the illustrated embodiment, the protruding piece 34 is composed of a single piece. However, the protruding piece may be composed of a plurality of pieces or composed of a single piece which is divided into a plurality of parts by one or more slits extending from the protruding end (lower end) of the single piece toward the base end (upper end). In the illustrated embodiment, two non-breaking connecting pieces 38a and 38b are provided on both circumferential sides of the protruding piece 34. However, one or at least three non-breaking connecting pieces may also be provided.

Claims

1. A synthetic resin container lid adapted for a container having an external thread formed on the outer peripheral surface of its mouth neck portion and engaging claw portions located below the external thread, the synthetic resin container lid comprising: A main body having a top wall and a cylindrical skirt wall hanging down from the periphery of the top wall, wherein an internal thread adapted to be screwed with the external thread is formed on the inner peripheral surface of the skirt wall; and A cylindrical anti-tampering skirt portion connected to the skirt wall of the main body through a plurality of breakable bridge portions arranged at intervals in the circumferential direction, wherein an engaging mechanism adapted to engage with the engaging claw portions is provided on the inner peripheral surface of the anti-tampering skirt portion; The engaging mechanism is composed of a plurality of engaging pieces arranged at intervals in the circumferential direction and extending upward and radially inward from the base end connected to the anti-tampering skirt portion, or is composed of an annular engaging piece extending continuously in the circumferential direction and extending upward and radially inward from the base end connected to the anti-tampering skirt portion; A protruding piece protruding downward is provided on the skirt wall of the main body; And A non-breakable connecting piece is provided for connecting the skirt wall of the main body and the anti-tampering skirt portion and allowing the main body to move upward relative to the anti-tampering skirt portion; Wherein, at least in the angular region where the protruding piece exists, an extension portion is formed on the engaging piece, and the extension portion is located between the engaging claw portion of the mouth neck portion and the anti-tampering skirt portion in a state where the synthetic resin container lid is mounted on the mouth neck portion; A raised portion is formed on the outer surface of the protruding piece; And When the main body is rotated in the opening direction to unseal the mouth neck portion sealed by the synthetic resin container lid mounted thereon, the breakable bridge portions break, such that the main body moves upward from the anti-tampering skirt portion, and when the main body pivots relative to the anti-tampering skirt portion around a predetermined portion of the non-breakable connecting piece by more than a predetermined angle, the lower portion of the protruding piece elastically crosses over the extension portion until the raised portion of the protruding piece contacts the outer surface of the extension portion.

2. The synthetic resin container lid according to claim 1, wherein, An engaging protrusion is formed on the inner surface of the engaging piece, and the engaging protrusion protrudes radially inward below the engaging claw portion in a state where the synthetic resin container lid is mounted on the mouth neck portion.

3. The synthetic resin container lid according to claim 1, wherein, The extension portion is also formed in a region other than the angular region where the protruding piece exists.

4. The synthetic resin container lid according to claim 1, wherein, The engaging mechanism is composed of a plurality of engaging pieces arranged at intervals in the circumferential direction and extending upward and radially inward from the base end connected to the anti-tampering skirt portion, and the extension portion is formed on both circumferential side portions of each of the engaging pieces.

5. The synthetic resin container lid according to claim 1, wherein, The outer surface of the extension portion gradually protrudes radially outward in the upward direction and then gradually retracts radially inward in the upward direction.

6. The synthetic resin container lid according to claim 5, wherein, The portion where the outer surface of the extension portion gradually protrudes radially outward in the upward direction is concave arc-shaped in a longitudinal section.

7. The synthetic resin container lid according to claim 1, wherein An arc-shaped protrusion extending continuously in the circumferential direction is formed at the lower end portion of the outer peripheral surface of the skirt wall and the upper end portion of the outer peripheral surface of the anti-tampering skirt portion except for a specific region where the protruding piece and the non-breakable connecting piece exist; and The radially protruding amount of the raised portion corresponds to the radially protruding amount of the protrusion.

8. The synthetic resin container lid according to claim 1, wherein, A mating interlocking mechanism is formed on the outer surface of the extension portion, and an interlocking mechanism that interlocks with the mating interlocking mechanism is formed on the raised portion of the protruding piece.

9. The synthetic resin container lid according to claim 8, wherein the outer surface of the extension portion gradually projects radially outward in the upward direction and then gradually retracts radially inward in the upward direction; a boundary region between the portion that gradually projects radially outward in the upward direction and the portion that gradually retracts radially inward in the upward direction serves as the mating interlocking mechanism; and at least one protrusion or groove extending circumferentially formed on the raised portion of the protruding piece serves as the interlocking mechanism.

10. A synthetic resin container lid suitable for a container having an external thread formed on the outer peripheral surface of the mouth neck portion and an engaging claw portion located below the external thread, the synthetic resin container lid comprising: a main body having a top wall and a cylindrical skirt wall hanging down from the periphery of the top wall, wherein an internal thread that engages with the external thread is formed on the inner peripheral surface of the skirt wall; and a cylindrical anti-tampering skirt portion connected to the skirt wall of the main body by a plurality of breakable bridge joints arranged at circumferential intervals, wherein an engaging mechanism that engages with the engaging claw portion is provided on the inner peripheral surface of the anti-tampering skirt portion; the engaging mechanism is composed of a plurality of engaging pieces arranged at circumferential intervals and extending upward and radially inward from the base end connected to the anti-tampering skirt portion, or is composed of an annular engaging piece extending continuously in the circumferential direction and extending upward and radially inward from the base end connected to the anti-tampering skirt portion; a protruding piece protruding downward is provided on the skirt wall of the main body; and a non-breakable connecting piece that connects the skirt wall of the main body and the anti-tampering skirt portion and allows the main body to move upward relative to the anti-tampering skirt portion is provided; wherein, at least in the angular region where the protruding piece exists, an extension portion is formed on the engaging piece, the extension portion is located between the engaging claw portion of the mouth neck portion and the anti-tampering skirt portion when the synthetic resin container lid is installed on the mouth neck portion, and a mating interlocking mechanism is formed on the outer surface of the extension portion; an interlocking mechanism that interlocks with the mating interlocking mechanism is formed on the outer surface of the protruding piece; when the main body rotates in the opening direction to unseal the mouth neck portion sealed by the synthetic resin container lid installed thereon, the breakable bridge joints break, so that the main body moves upward from the anti-tampering skirt portion, and when the main body pivots relative to the anti-tampering skirt portion around a predetermined portion of the non-breakable connecting piece by more than a predetermined angle, the lower portion of the protruding piece elastically crosses over the extension portion until the interlocking mechanism of the protruding piece interlocks with the mating interlocking mechanism of the extension portion.

11. The synthetic resin container lid according to claim 10, wherein the outer surface of the extension portion gradually projects radially outward in the upward direction and then gradually retracts radially inward in the upward direction; a boundary region between the portion that gradually projects radially outward in the upward direction and the portion that gradually retracts radially inward in the upward direction serves as the mating interlocking mechanism; and At least one protrusion or groove extending circumferentially is formed on the outer surface of the protruding piece to serve as the interlocking mechanism.

12. The synthetic resin container lid according to claim 10, wherein, Engagement protrusions are formed on the inner surface of the engagement piece, and the engagement protrusions protrude radially inward below the engagement claw portion in a state where the synthetic resin container lid is mounted on the mouth neck portion.

13. The synthetic resin container lid according to claim 10, wherein, The extension portion is also formed in a region other than the angular region where the protruding piece is present.

14. The synthetic resin container lid according to claim 10, wherein the engagement mechanism is composed of a plurality of engagement pieces that are circumferentially spaced apart and extend upward and radially inward from a base end connected to the anti-tampering skirt portion, and the extension portion is formed on both circumferential side portions of each of the engagement pieces.

15. The synthetic resin container lid according to claim 10, wherein, The outer surface of the extension portion gradually protrudes radially outward in the upward direction and then gradually retracts radially inward in the upward direction.

16. The synthetic resin container lid according to claim 15, wherein, A portion of the outer surface of the extension portion that gradually protrudes radially outward in the upward direction is concave arc-shaped in a longitudinal section.

Images