JP4098797B2 - Plastic container lid - Google Patents

Description

  The present invention includes a synthetic resin container lid integrally formed of synthetic resin, more specifically, a circular top wall and a cylindrical skirt wall depending from the periphery of the top wall, and the inner surface of the top wall is provided below. The present invention relates to a synthetic resin container lid having a cylindrical seal piece that extends.

As a container lid for a beverage container, a synthetic resin container lid formed as a whole from an appropriate synthetic resin such as polypropylene or polyethylene has been proposed and put into practical use. Such a container lid includes a circular top wall and a cylindrical skirt wall depending from the periphery of the top wall, and a cylindrical seal piece extending downward is formed on the inner surface of the top wall. In the container lid disclosed in FIG. 3 of Patent Document 1 below, two cylindrical pieces extending downward, that is, an outer cylindrical piece and an inner cylindrical seal piece are formed on the inner surface of the top wall. ing. An annular seal ridge adjacent to the base of the outer cylindrical piece is further formed on the inner surface of the top wall. A female thread is formed on the inner peripheral surface of the skirt wall. Such a container lid is attached to a container in which a male thread is formed on the outer peripheral surface of the mouth and neck. When the female thread of the container lid is screwed onto the male thread of the mouth and neck, and the container lid is attached to the mouth and neck, the inner cylindrical seal piece is brought into close contact with the inner peripheral surface of the mouth and neck, and is also annular The seal ridge is brought into close contact with the boundary region between the outer peripheral surface and the top surface in the mouth and neck. The outer cylindrical piece is not in close contact with the outer peripheral surface of the mouth-and-neck portion, but is brought into relatively weak contact with each other, and assists in close contact of the annular seal protrusion with the boundary region between the outer peripheral surface and the top surface in the mouth-and-neck portion.
Japanese Patent Laid-Open No. 10-35699

  Thus, the conventional container lid of the above-described form has the following problems to be solved. In the conventional container lid of the above-described form, when the container lid is attached to the mouth / neck portion of the container, the mouth / neck portion is sufficiently securely sealed, and when opening the mouth / neck portion, it is appropriate without requiring excessive torque. It is necessary to satisfy the basic requirement that the container lid can be detached from the mouth-and-neck portion by applying a sufficient torque to the container lid and rotating the container lid. In addition, when opening the mouth and neck, it is also important that the sealing of the mouth and neck is released after the container lid has been rotated over the required rotation angle. This point will be described in more detail. Usually, a weakening line extending in the circumferential direction is formed on the skirt wall of the container lid, and the skirt wall has a main portion above the weakening line and a tamper below the weakening line. The female thread is formed on the inner peripheral surface of the main portion, and a locking means which may be in an appropriate form is formed on the inner peripheral surface of the tamper evidence hem. ing. When the container lid is attached to the mouth and neck portion of the container, the locking means is locked to the locking jaw portion formed on the outer peripheral surface of the mouth and neck portion. When the container lid is rotated in the opening direction in order to open the mouth and neck of the container, the weakening line is broken at least partially, thereby releasing the locking means from the locking jaw and releasing the locking of the mouth and neck. It is allowed to remove the container lid from the container. When rotating the container lid in the opening direction, it is important that the mouth-and-neck seal is released after the weakening line is at least partially broken. If the mouth and neck seal is released before the weakening line is at least partially broken, the container lid is pushed and rotated in the open direction, and the mouth and neck seal is released, but the weakening line is released. Will not break, so there will be no evidence that the container lid has been lifted and the mouth-and-neck seal has been released. However, in the conventional container lid of the above-described form, the container lid is rotated at a predetermined rotation angle due to manufacturing tolerances of the container lid and / or mouth / neck portion or thermal changes received by the container lid and / or mouth / neck portion. There is a tendency for the mouth and neck to become unsealed before being rotated to the full, and it may also fail to meet the basic requirements described above.

  The present invention has been made in view of the above-mentioned facts, and its main technical problem is that when the container lid is attached to the mouth and neck of the container, the mouth and neck are sufficiently sealed, and the mouth and neck are opened. The container lid can be detached from the mouth and neck by applying an appropriate torque to the container lid and rotating the container lid without requiring excessive torque, and the container can be opened when opening the mouth and neck. To provide a new and improved synthetic resin container lid in which the sealing of the mouth and neck is released after the lid is rotated over the required rotation angle.

According to the present invention, a synthetic resin integrally formed from a synthetic resin, comprising a circular top wall and a cylindrical skirt wall depending from the peripheral edge of the top wall as a container lid for achieving the main technical problem. In the container lid,
On the inner surface of the top wall, the outer cylindrical seal piece extending downward, the inner cylindrical seal piece extending downward, and the outer cylindrical seal piece and the inner cylindrical seal piece are positioned. An annular seal ridge bulging downward is formed,
When the container lid is attached to the mouth and neck of the container, the inner peripheral surface of the outer cylindrical seal piece is brought into close contact with the outer peripheral surface of the mouth and neck portion, and the outer peripheral surface of the inner cylindrical seal piece is the inner periphery of the mouth and neck portion. The annular seal ridge is brought into close contact with the top surface of the mouth and neck,
In the state before the container lid is attached to the mouth / neck portion of the container, the maximum outer diameter D3 of the outer peripheral surface of the inner cylindrical sealing piece, which is in close contact with the inner peripheral surface of the mouth / neck portion, is the covering of the mouth / neck portion. Closely larger than the inner diameter D4 of the inner peripheral surface, and 0.25 mm ≦ (D3−D4) ≦ 1.50 mm,
The outer peripheral surface of the inner cylindrical seal piece extends obliquely outwardly in the downward direction at an inclination angle θ1 of 5 to 25 degrees with respect to the central axis of the container lid, and then extends toward the central axis. With a tilt angle θ2 of 5 to 30 degrees with respect to the bottom and extending radially inward and extending downward,
The upper part of the inner peripheral surface of the inner cylindrical seal piece is inclined radially outwardly downward at an inclination angle θ3 of 7 to 30 degrees with respect to the central axis and larger than the inclination angle θ1. Extended,
The wall thickness of the inner cylindrical seal piece is gradually decreased downward,
An inner peripheral surface of the outer cylindrical seal piece extends with an inclination angle θ6 with respect to the central axis and inclining radially outwards downward, and then circularly outwards downward. Extending in an arc,
A container lid is provided.

  The container lid of the present invention is not limited thereto, but a container formed from an appropriate synthetic resin such as polyethylene terephthalate is filled with contents at room temperature in a sterile or sterilized state (so-called aseptic filling). And can be used particularly advantageously. As is well known to those skilled in the art, a synthetic resin container filled with contents at room temperature usually does not crystallize when the mouth and neck are heated, and the dimensional accuracy of the mouth and neck is considerably high.

The outer peripheral surface of the outer cylindrical seal piece is preferably cylindrical with the central axis as the central axis. Moreover, it is preferable that the lower part of the inner peripheral surface of the inner cylindrical seal piece has a cylindrical shape with the central axis as the central axis. Preferably, the outer peripheral surface of the inner tubular seal pieces that have a said maximum outer diameter D3 at a position spaced downwardly by a length L1 which is 2.50 to 3.50mm from the inside surface of the top wall.

  When (D3-D4) becomes too small, the sealing of the mouth and neck tends to be insufficient, and the mouth and neck before the container lid is rotated over the required rotation angle when opening the mouth and neck. There is a tendency for the seal to be released. On the other hand, when (D3-D4) becomes excessive, the torque that must be applied to the container lid when opening the mouth-neck portion tends to be excessive. The inner peripheral surface of the outer cylindrical seal piece extends downward and inclined radially outward at an inclination angle θ6 with respect to the central axis, and then radially downwards in a circular arc shape. Due to the extension, the attachment of the container lid to the mouth-and-neck portion can be carried out with sufficient ease, and there is virtually no possibility of a defective attachment of the container lid.

  In the container lid of the present invention, when the container lid is attached to the mouth / neck portion of the container, the mouth / neck portion is sufficiently sealed, and an appropriate torque is not required when opening the mouth / neck portion without requiring excessive torque. The container lid can be removed from the mouth and neck by rotating the container lid and the container lid is rotated, and when opening the mouth and neck, the container lid is rotated over the required rotation angle. The mouth and neck are unsealed.

  Hereinafter, a preferred embodiment of a synthetic resin container lid constructed according to the present invention will be described in more detail with reference to the accompanying drawings.

  Referring to FIG. 1, a container lid, generally designated 102, constructed according to the present invention is a container filled with room temperature contents in a sterile or sterilized state (a container to which aseptic filling is applied). It is conveniently applied to the mouth and neck, and is formed integrally from an appropriate synthetic resin such as polypropylene or polyethylene. The container lid 102 includes a circular top wall 104 and a skirt wall 106 depending from the periphery of the top wall 104. The skirt wall 106 is formed with a breakable line 108 extending in the circumferential direction. The skirt wall 106 has a main portion 110 above the breakable line 108 and a tamper evidence skirt 112 below the breakable line 108. It is divided into. An annular shoulder surface 114 facing downward is formed on the inner peripheral surface of the skirt wall 106, and a plurality of protrusions 116 extending downward from the annular shoulder surface 114 are formed at appropriate intervals in the circumferential direction. ing. The breakable line 108 causes a cutting blade (not shown) to act from the outer peripheral surface of the skirt wall 106 at an intermediate portion in the axial direction of the ridge 116, and at least a part of the ridge 116 remains to leave the skirt wall 106. It is formed by cutting. The portions of the ridges 116 that remain without being cut constitute a so-called bridge portion 118, and the tamper evidence skirt portion 112 is connected to the main portion 110 of the skirt wall 106 via the bridge portion 118. ing.

  On the outer peripheral surface of the main portion 110 of the skirt wall 106, a truncated cone-shaped portion 120 whose outer diameter gradually increases downward is formed in the vicinity of the lower end portion thereof. The outer peripheral surface of the tamper evidence skirt 112 is also formed into a truncated cone shape whose outer diameter gradually increases downward. A concave / convex shape 122 for preventing slipping of a finger hung thereon is formed on a portion of the outer peripheral surface of the main portion 110 located above the truncated cone-shaped portion 120. A female thread 124 is formed on the inner peripheral surface of the main portion 110 of the skirt wall 106. The female thread 124 is formed with a notch 126 extending in the axial direction at an appropriate interval in the circumferential direction. The notch 126 forms a so-called air passage when the mouth and neck of the container is opened.

  Locking means 128 is formed on the inner peripheral surface of the tamper evidence skirt 112. The locking means 128 in the illustrated embodiment is composed of a plurality of, for example, eight, protruding pieces 130 disposed at intervals in the circumferential direction. Each of the protruding pieces 130 protrudes from the base edge connected to the inner peripheral surface of the tamper evidence skirt 112 so as to incline upward in the radial direction. If desired, the locking means can be constituted by other appropriate forms of protruding pieces, protrusions or protrusions.

  On the inner surface of the top wall 104, there are an outer cylindrical seal piece 132, an inner cylindrical seal piece 134, and an annular seal protrusion 136 disposed between the outer cylindrical seal piece 132 and the inner cylindrical seal piece 134. It is important that it is formed.

  The description will be continued with reference to FIG. 2 together with FIG. 1. The central portion of the top wall 104, that is, the portion radially inward of the inner cylindrical seal piece 134 has a relatively large thickness T 3. The wall thickness T3-A of the top wall 104 at a portion radially outward from the annular seal protrusion 136 formed to be connected to the outer peripheral surface base of the inner cylindrical seal piece 134 is somewhat larger than the wall thickness T3. small. The wall thickness T3 may be 1.10 to 1.80 mm, and the wall thickness T3-A may be 0.90 to 1.70 mm.

  The inner cylindrical seal piece 134 in the container lid 102 extends downward from the inner surface of the top wall 104. The outer peripheral surface of the inner cylindrical seal piece 134 hangs down from the inner surface of the top wall 104 over a certain length substantially parallel to the central axis 138 (FIG. 1) of the container lid 102, and then the central axial line 138. Is inclined downward and radially outward (leftward in FIG. 2) at an inclination angle θ1, and then downwards at an inclination angle θ2 with respect to the central axis 138. Inclining and extending inward in the direction (rightward in FIG. 2). Therefore, the outer circumferential surface of the inner cylindrical seal piece 134 has a refracting portion 140 whose inclination direction is reversed. The inclination angle θ1 is preferably about 5 to 25 degrees, and the inclination angle θ2 is preferably about 5 to 30 degrees. In the cross-sectional view illustrated in FIG. 2, the upper end portion of the outer peripheral surface of the inner cylindrical seal piece 134 extends substantially linearly, and the main portion including the refracting portion 140 has a convex shape having a relatively large radius of curvature (such a convex portion). The inclination angles θ1 and θ2 are angles formed by tangent lines at the respective portions and the central axis 138), and the lower end portion extends in a substantially arc shape. Since the outer peripheral surface of the inner cylindrical seal piece 134 has the form as described above, the inner cylindrical seal piece 134 has a maximum outer diameter D3 at the bent portion 140. As can be understood by referring to FIG. 2, the bent portion 140 of the inner cylindrical seal piece 134 is brought into intimate contact with the inner peripheral surface 162 of the mouth-and-neck portion 150 of the container, so that the maximum outer diameter D3 is the inner cylindrical shape. This is the maximum outer diameter of the portion of the seal piece 134 that is brought into close contact with the mouth / neck portion 150 of the container. The portion having the maximum outer diameter D3 is preferably a position spaced downward from the inner surface of the top wall 104 by a length L1 of 2.50 to 3.50 mm.

The upper part of the inner peripheral surface of the inner cylindrical sealing piece 134, has been extended to be inclined radially outward downward at an inclination angle θ3 with respect to the central axis 138, inner cylindrical sealing piece The lower part of the inner peripheral surface of 134 has a cylindrical shape with the central axis 138 as the central axis . The inclination angle θ3 may be about 7 to 30 degrees. Since the outer peripheral surface and inner peripheral surface of the inner cylindrical seal piece 134 are formed as described above, the wall thickness of the inner cylindrical seal piece 134 is lowered as clearly understood by referring to FIG. It is gradually decreased toward the center.

The outer cylindrical seal piece 132 in the container lid 102 is also extended downward from the inner surface of the top wall 104. The extension length of the outer cylindrical seal piece 132 is shorter than the extension length of the inner cylindrical seal piece 134, and the extension length of the outer cylindrical seal piece 132 is equal to the extension length of the inner cylindrical seal piece 134. About one third. In the case of a container to which aseptic filling is applied, it is not necessary to heat and crystallize the mouth and neck after forming the container into a required shape, and therefore the dimensional accuracy of the mouth and neck is relatively high. Therefore, according to the experience of the inventors, the requirement for sealing the mouth and neck is basically sufficient to be sealed by the inner cylindrical seal piece 134. The outer cylindrical seal piece 132 contributes to the positioning of the container lid 102 when the container lid 102 is attached to the mouth / neck portion or prevention of bacteria from entering from the outside. From such a point of view, the inner peripheral surface of the outer cylindrical seal piece 132 is inclined outwardly in the radial direction at an inclination angle θ6 with respect to the central axis 138, and then extends linearly. It extends in a circular arc shape outward in the radial direction downward. The inclination angle θ6 may be about 10 to 25 degrees. As can be seen by referring to FIG. 2, when the container lid 102 is mounted as required to the container neck 150, the annular seal ridge 136 is brought into close contact with the top surface 156 of the mouth neck 150, The outer cylindrical seal piece 132 is in close contact with the outer peripheral surface 158 of the mouth-and-neck portion 150 from the portion indicated by the number 132A in FIG. Therefore, the inner diameter of the portion indicated by the number 132A on the inner peripheral surface of the outer cylindrical seal piece 132 is the minimum inner diameter D1 at the portion that is brought into close contact with the outer peripheral surface 158 of the mouth-and-neck portion 150. The outer peripheral surface of the outer cylindrical seal piece 132 has a cylindrical shape with the central axis 138 as the central axis .

  The annular seal protrusion 136 is formed to be connected to the outer peripheral surface base portion of the inner cylindrical seal piece 134 and has a substantially rectangular shape as a whole, and the lower end portion of the outer peripheral surface has an arc shape with a small radius of curvature. Have. The protruding amount of the annular seal protrusion 136 is considerably smaller than the extended length of the inner cylindrical seal piece 134 and the outer cylindrical seal piece 132, and the inner cylindrical seal piece 134 and the outer cylindrical seal piece 132 are radially inward. However, the annular seal ridge 136 has substantially no flexibility.

  1 and 2, a part of the mouth and neck of the container to which the container lid 102 is applied is also shown by a two-dot chain line. A container that can be formed from an appropriate synthetic resin such as polyethylene terephthalate has a substantially cylindrical mouth-and-neck portion 150. A male thread 152 and an annular locking jaw 154 (FIG. 1) positioned below the male thread 152 are formed on the outer peripheral surface of the mouth and neck portion 150. The upper end located above the male thread 152 has an annular top surface 156 that extends substantially horizontally and a cylindrical outer peripheral surface 158 that extends substantially vertically. The inner peripheral surface 162 of the mouth-and-neck portion 150 has a cylindrical shape that extends substantially vertically. When the container lid 102 is attached to the mouth-and-neck portion 150 of such a container and the mouth-and-neck portion 150 is sealed, the container lid 102 is fitted on the mouth-and-neck portion 150 and closed, that is, FIG. 1 and FIG. , The screw thread 124 of the container lid 102 is screwed onto the male thread 152 of the mouth-and-neck portion 150. When the container lid 102 is rotated in the closing direction with the required torque so as to be in the state shown in FIGS. 1 and 2, the inner cylindrical seal piece 134 is caused to enter the mouth-and-neck portion 150, and the inner cylindrical seal piece 134. The outer peripheral surface of the refracting portion 140 is brought into close contact with the cylindrical inner peripheral surface 162 of the mouth-and-neck portion 150. The annular seal protrusion 136 is brought into intimate contact with the annular top surface 156 of the mouth and neck portion 150, and the inner peripheral surface of the outer cylindrical seal piece 132 is brought into intimate contact with the cylindrical outer peripheral surface 158 of the mouth and neck portion 150. The locking means 128 formed on the tamper evidence skirt 112 of the container lid 102 is elastically deformed radially outward and passes through the annular jaw 154 of the mouth-and-neck 150, and then elastically restored. To be locked to the lower surface of the annular jaw 154.

  As clearly understood by referring to FIG. 2, in the container lid 102 configured according to the present invention, the outer cylindrical seal piece 132 is in a state before the container lid 102 is attached to the mouth / neck portion 150 of the container. The minimum inner diameter D1 is smaller than the outer diameter D2 of the outer peripheral surface 158 of the mouth-and-neck portion 150 to which the outer cylindrical seal piece 132 is brought into close contact, 0.05 mm ≦ (D2-D1) ≦ 0.60 mm, and The maximum inner diameter D3 of the inner cylindrical seal piece 134 is larger than the inner diameter D4 of the inner peripheral surface 162 of the mouth-and-neck portion 150 to which the inner cylindrical seal piece 134 is brought into close contact, and 0.25 mm ≦ (D3-D4) ≦. It is desirable that it is 1.50 mm. According to the experience of the present inventors, when (D2-D1) and (D3-D4) are too small, the sealing of the mouth-and-neck portion 150 tends to be insufficient, and the mouth-and-neck portion 150 is opened. Therefore, before the container lid 102 is rotated over the required rotation angle, the mouth / neck portion 150 tends to be unsealed. On the other hand, if (D2-D1) and (D3-D4) are excessive, they must be added to the container lid 102 when attaching the container lid 102 to the mouth / neck portion 150 and when removing the container lid 102 from the mouth / neck portion 150. There is a tendency for excessive torque to be excessive.

  When opening the mouth-and-neck portion 150 of the container, the container lid 102 is rotated in the opening direction, that is, counterclockwise when viewed from above in FIGS. In this way, the tamper evidence skirt 112 has the locking means 128 formed on the inner peripheral surface thereof locked on the lower surface of the annular jaw portion 154 formed on the outer peripheral surface of the mouth-and-neck portion 150. The other portion of the container lid 102 is raised as the male screw 152 and the female screw 124 are unscrewed by rotation. Accordingly, a considerable stress is generated in the breakable line 108 formed in the skirt wall 106, more specifically, in the bridge portion 118, so that the bridge portion 118 is broken, and the tamper evidence skirt 112 is formed on the skirt wall 106. It is separated from the main part 110. Next, the portion of the container lid 102 other than the tamper evidence skirt 112 is freely moved upward with rotation and detached from the mouth-and-neck portion 150.

  In the container lid 102 described above, when opening the mouth / neck portion 150 of the container, all the bridging portions 118 in the breakable line 108 formed in the skirt wall 106 of the container lid 102) are broken, and the tamper The evidence skirt 112 is completely separated from the main portion 110 of the skirt wall 106, and the tamper evidence skirt 112 remains in the mouth neck 150 without being detached from the mouth neck 150, but if desired, At least one of the bridging portions 118 in the breakable line 108 is made to be a strong bridging portion that is maintained without being broken, and the breakable line (not shown) extends in the axial direction to the tamper evidence skirt 112. When the mouth / neck portion 150 is opened, the breakable line extending in the axial direction is broken to form the tamper evidence skirt 112. The tamper-evidence hem 112 that continues to be connected to the main part 110 of the skirt wall 106 via the strong bridge that is expanded from the endless ring to the end-band shape and is maintained without breaking is also detached from the mouth-and-neck part 150. Can also be made.

The figure which shows the suitable embodiment of the container lid comprised according to this invention in part with a side view, and a part with sectional drawing. The expanded partial sectional view which expands and shows a part of container lid of FIG.

Explanation of symbols

102: Container lid 104: Top wall 106: Skirt wall 132: Outer cylindrical seal piece 134: Inner cylindrical seal piece 136: Annular seal ridge 150: Container neck

Claims (4)

In a synthetic resin container lid integrally formed from synthetic resin, comprising a circular top wall and a cylindrical skirt wall depending from the periphery of the top wall,
On the inner surface of the top wall, the outer cylindrical seal piece extending downward, the inner cylindrical seal piece extending downward, and the outer cylindrical seal piece and the inner cylindrical seal piece are positioned. An annular seal ridge bulging downward is formed,
When the container lid is attached to the mouth and neck of the container, the inner peripheral surface of the outer cylindrical seal piece is brought into close contact with the outer peripheral surface of the mouth and neck portion, and the outer peripheral surface of the inner cylindrical seal piece is the inner periphery of the mouth and neck portion. The annular seal ridge is brought into close contact with the top surface of the mouth and neck,
In the state before the container lid is attached to the mouth / neck portion of the container, the maximum outer diameter D3 of the outer peripheral surface of the inner cylindrical sealing piece, which is in close contact with the inner peripheral surface of the mouth / neck portion, is the covering of the mouth / neck portion. Closely larger than the inner diameter D4 of the inner peripheral surface, and 0.25 mm ≦ (D3−D4) ≦ 1.50 mm,
The outer peripheral surface of the inner cylindrical seal piece extends obliquely outwardly in the downward direction at an inclination angle θ1 of 5 to 25 degrees with respect to the central axis of the container lid, and then extends toward the central axis. With a tilt angle θ2 of 5 to 30 degrees with respect to the bottom and extending radially inward and extending downward,
The upper part of the inner peripheral surface of the inner cylindrical seal piece is inclined radially outwardly downward at an inclination angle θ3 of 7 to 30 degrees with respect to the central axis and larger than the inclination angle θ1. Extended,
The wall thickness of the inner cylindrical seal piece is gradually decreased downward,
An inner peripheral surface of the outer cylindrical seal piece extends with an inclination angle θ6 with respect to the central axis and inclining radially outwards downward, and then circularly outwards downward. Extending in an arc,
A container lid characterized by that. The container lid according to claim 1, wherein the outer peripheral surface of the outer cylindrical seal piece has a cylindrical shape with the central axis as the central axis . The container lid according to claim 1 or 2, wherein a lower part of an inner peripheral surface of the inner cylindrical seal piece has a cylindrical shape having the central axis as the central axis . The outer peripheral surface of the inner cylindrical seal piece has the maximum outer diameter D3 at a position spaced downward by a length L1 of 2.50 to 3.50 mm from the inner surface of the top wall . The container lid in any one .

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