JPH0442253B2 - - Google Patents

Description

[Detailed description of the invention]

<Technical Field> The present invention relates to a container lid made of synthetic resin having a pilfer-blue characteristic, and more specifically, a container lid made of a synthetic resin having a pilfer-blue characteristic, and more specifically, a container lid having a male thread and a locking jaw located below the male thread on the outer circumferential surface. Applies to containers with a neck and neck,
The present invention relates to a synthetic resin container lid having pilfer-blue characteristics. <Prior Art> Recently, container lids with pilfer-a-bluff properties for containers such as beverage bottles have been developed.
Synthetic resin container lids have been proposed and put into practical use in place of metal container lids. A typical example of such a synthetic resin container lid is disclosed in Japanese Patent Application Laid-open No. 1983-
Publication No. 74445, Japanese Patent Application Publication No. 58-30949, and Japanese Patent Application Publication No. 1987-30949
The container lid disclosed in Japanese Patent No. 58-51116 can be mentioned. The container lid disclosed in the above publication has a top wall and a cylindrical skirt wall that hangs down from the periphery of the top wall. A weakened line extending in the circumferential direction is formed in the skirt wall, and the skirt wall is divided into a main portion above the weakened line and a pilferable blue hem portion below the weakened line. A female thread is formed on the inner surface of the main part, and a female thread is formed on the inner surface of the hem of the pilfer valve, which is inclined in the opposite direction to the direction of rotation of the container lid when the container lid is attached to the mouth and neck of the container. A plurality of locking flap pieces projecting radially inward are formed at intervals in the circumferential direction. The synthetic resin container lid as described above is applied to a container having a neck portion in which a male thread and a locking jaw portion located below the male thread are formed on the outer peripheral surface. When closing the mouth and neck of a container with a container lid, the container lid is fitted onto the mouth and neck and rotated in a predetermined direction, that is, the closing direction, and the female thread on the container lid is screwed into the male thread on the mouth and neck. Match. As a result, the container lid rotates in the closing direction relative to the mouth and neck and moves downward in the axial direction. At this time, the locking flap piece formed on the inner surface of the hem of the pillowcase is interfered with by the locking jaw formed on the outer surface of the mouth and neck, and is elastically bent radially outward. . When it completely passes through the locking jaw, it elastically returns radially inward and locks onto the lower surface of the locking jaw. When opening the neck of the container, the container lid is rotated in the opposite direction to the closing direction, that is, in the opening direction. In this way, the female thread of the container lid is moved along the male thread of the mouth and neck, so that the container lid rotates in the opening direction and moves upward in the axial direction.
However, since the locking flap piece formed on its inner surface engages with the lower surface of the locking jaw of the mouth and neck, the pillfer flap hem of the container lid cannot move upward in the axial direction. Therefore, considerable stress is generated in the line of weakness formed in the skirt wall of the container lid. In this way, the weakened line is completely broken and the skirt wall is separated into the main part and the hem of the pilfer jacket, or the weakened line is broken leaving only a part and is attached to the hem of the pilfer jacket. The line of weakness extending in the axial direction is broken, and the hem of the pilfer jacket is opened from an endless ring shape to an end band shape. After that, the other parts of the container lid, leaving the separated pilf-fur-bloof hem, or the entire container lid including the pilf-fur-bloof hem are removed from the neck and neck, and the mouth and neck are opened. <Problem to be solved by the invention> Therefore, the container lid of the above form has the following two problems.
It is important that two requirements are met. First, when the neck of the container is closed with the container lid, the locking flap piece can be elastically deflected radially outward with sufficient ease to pass through the locking jaw; It is thus important to ensure that excessive stress is not created in the line of weakness, leading to rupture of the line of weakness. Second, when opening the neck of the container, the locking flap piece is sufficiently securely locked in the locking jaw, thus allowing the so-called slip-off without causing the intended rupture of the line of weakness. (The locking flap bends outward in the radial direction and passes through the locking jaw.) This causes the container lid to separate from the mouth and neck (thus, the pilfer roof characteristics are damaged). It is important to ensure that this is avoided. In order to satisfy these two requirements, it is necessary to sufficiently reduce the required downward rotational torque that must be applied to the container lid when the locking flap piece is passed through the locking jaw from axially upward to downward. , the necessary upward rotational torque that must be applied to the container lid when the locking flap piece is to be passed axially from below upwards through the locking jaw is made sufficiently large, and the line of weakening is adjusted as desired. It is necessary to set the necessary rotational torque that must be applied to the container lid in order to cause it to break between the above-mentioned necessary downward rotational torque and the above-mentioned necessary upward rotational torque. However, in conventional container lids, it is not possible to create a sufficient difference between the above-mentioned required downward rotational torque and the above-mentioned necessary upward rotational torque, and therefore, due to manufacturing errors etc., the above-mentioned first requirement is not met. Or, the second requirement above was often not met. The present invention has been made in view of the above-mentioned facts, and the technical problem to be solved is to improve the container lid of the above-mentioned form to sufficiently reduce the required downward rotational torque and to sufficiently reduce the required upward rotational torque. The objective is to make the difference large enough to create a sufficient difference between the two, thereby ensuring that both the first and second requirements are satisfied. <Means for Solving the Problems> In order to achieve the above-mentioned technical problems, in the present invention, at least a part of each of the locking flap pieces, which conventionally had a single planar shape, is made so that the upper part is higher than the lower part. The shape is twisted in the radially inward direction. That is, according to the present invention, a container having a neck portion having a male thread and a locking jaw portion located below the male thread on the outer circumferential surface has a pilfer-blue characteristic. The container lid is made of synthetic resin and includes a top wall and a cylindrical skirt wall that hangs down from the periphery of the top wall, the skirt wall has a weakened line extending in the circumferential direction, and the skirt wall is divided into a main part above the weakened line and a hem part of the pilfer jacket below the weakened line, and the inner surface of the main part is screwed to the male thread of the mouth and neck part. A female thread is formed on the inner surface of the hem of the pilfer blue, and projects radially inward while being inclined in a direction opposite to the direction of rotation of the container lid when the container lid is attached to the mouth and neck. In a container lid in which a plurality of locking flap pieces are formed at intervals in the circumferential direction; at least a portion of each of the locking flap pieces:
There is provided a container lid characterized in that the upper part is twisted in a direction in which the upper part is more radially inward than the lower part. <Function> According to the container lid of the present invention, <Example> described below
As can be clearly understood from the descriptions of ``Comparative Example'' and ``Comparative Example'', the required downward rotational torque is considerably reduced and the required upward rotational torque is considerably reduced compared to the conventional container lid in which each of the locking flap pieces has a single planar shape. Torque is increased considerably. The theoretical reason for this is not necessarily clear, but when the container lid is lowered relative to the mouth and neck, the lower part of each of the locking flap pieces that first interferes with the locking jaw is twisted radially outward. (therefore, the amount of interference with the locking jaw is reduced), the required downward rotational torque is reduced, and when the container lid is raised relative to the mouth and neck. , the upper part of each of the locking flap pieces that locks on the lower surface of the locking jaw and prevents it from rising is twisted radially inward (therefore, the amount of interference with the locking jaw is increased). ), it is presumed that the required upward rotational torque is increased. <Preferred Embodiments of the Invention> Hereinafter, preferred embodiments of the improved synthetic resin container lid according to the present invention will be described in more detail with reference to the accompanying drawings. To explain with reference to FIG.
It has an integrally formed body with a cylindrical skirt wall 6 depending from the periphery of the body. Such a main body can be formed from a suitable synthetic resin material such as polyolefin resin by compression molding or injection molding. In the illustrated example, an annular protrusion 8 is formed at the upper end of the inner surface of the skirt wall 6 and projects radially inward therefrom, and this annular protrusion 8 and the inner surface of the top wall 4 A generally circular sealing liner 10, formed separately from the body, is disposed within an area defined by. Such a sealing liner 10 can be molded in position from a suitable synthetic resin material, for example after molding the main body, by an embossing method which is known per se. If desired, instead of forming the sealing liner 10 separately from the main body, a sealing ridge of a suitable form can be integrally formed on the inner surface of the top wall 4. The skirt wall 6 has a weakened line 1 extending in the circumferential direction.
2 is formed, and the skirt wall 6 is divided into a main part 14 above the weakened line 12 and a pilfer blouf hem part 16 below the weakened line 12. The weakened line 12 may be a so-called score formed by reducing the thickness of the material, but in the illustrated example, the weakened line 12 is formed by a plurality of circumferentially extending slits ( The pilfer roof hem 16 is connected to the main portion 14 by the plurality of bridges 20. It is connected. In the illustrated example, a plurality of bridge sections 2
One specific bridge portion 20A among the bridge portions 20 has a larger width in the circumferential direction than the other bridge portions 20, and therefore has increased strength. A weakened line 22 extending in the axial direction is formed in the pilfer jacket hem 16 at a position adjacent to one edge in the circumferential direction of the specific bridge portion 20A. This weakened line 22 may be a score or a perforation. As clearly shown in FIG. 1, it is generally convenient that the main portion 14 of the skirt wall 6 is relatively thick and the pilfered buff hem 16 is relatively thin. A female thread 24 is formed on the inner surface of the main portion 14 . Further, it is convenient that the outer surface of the main portion 14 is formed with an uneven or knurled shape 26 to prevent fingers from slipping when rotating the container lid 2 by placing a finger thereon. On the other hand, a plurality of (22 in the illustrated case) locking flap pieces 28 are formed on the inner surface of the pilfer roof hem 16 at intervals in the circumferential direction. Referring to FIG. 2 in conjunction with FIG. 1, each of the locking flap pieces 28 extends from a base edge 30 connected to the inner surface of the pillow flap hem 16 in the direction indicated by arrow 32 in FIG. (In other words, this is the rotation direction of the container lid 2 when the container lid 2 is attached to the mouth and neck of the container as described later, and is tilted in the opposite direction to the clockwise direction when viewed from above in FIG. 1). , projecting radially inward. Locking flap piece 2 in the illustrated example
8 itself is approximately rectangular in shape. If desired, each of the locking flap pieces 28 itself can have an appropriate shape such as a generally trapezoidal shape or a generally triangular shape, the axial width of which gradually decreases from the base edge 30 toward the free end. Furthermore, in the illustrated embodiment, the base edge 30 of each of the locking flap pieces 28 extends substantially vertically in the axial direction of the container lid 2. However, if desired, the base edge 30 of each locking flap piece 28 can be angled axially downwardly in a suitable direction, i.e., in the direction indicated by arrow 32 in FIG. 2, or in the opposite direction. It can also be made to extend at an angle. The above-described configuration of the illustrated container lid 2 does not constitute a new feature of the container lid 2 improved according to the present invention, but merely represents an example of the container lid to which the present invention is applied. According to the present invention, it is important that at least a portion of each of the locking flap pieces 28 has a twisted shape such that the upper portion is more radially inward than the lower portion. Referring to FIGS. 2 and 3, in the conventional container lid, each of the locking flap pieces 28 has a single planar shape as shown by the two-dot chain line. In contrast, in the illustrated embodiment constructed in accordance with the present invention, each of the locking flap pieces 28 has its free end oriented in its entirety relative to the base edge 30 in the direction indicated by arrow 34 in FIG. As can be seen from FIG. 3, each of the locking flap pieces 28 is formed into a relatively twisted shape, and as can be seen from FIG. I am forced to become. Thus, in the bottom view shown in FIG. 3, the radially inner surface 36 of each locking flap piece 28 is visible. As clearly illustrated in Figure 3,
In the illustrated embodiment, both the lower edge 38 and the upper edge 40 of each of the locking flap pieces 28 are smooth curves, preferably arcs, in the bottom view, FIG. The radially inner surface 36 (and radially outer surface) of each of 28 is defined by a smoothly extending curved surface from the lower edge 38 to the upper edge 40. In this case, it is important that the radius of curvature of the lower edge 38 in the bottom view, FIG. 3, is smaller than the radius of curvature of the upper edge 40. Bottom view i.e. 3rd
If the radius of curvature of the lower edge 38 in the figure is larger than the radius of curvature of the upper edge 40, the twisting direction of the locking flap piece 28 is reversed, and the radius of the locking flap piece 28 in the bottom view, that is, FIG. The radially outer surface appears instead of the radially inner surface 36 (and in such a case, the above-mentioned required downward rotational torque increases rather than decreases, and the above-mentioned necessary upward rotational torque decreases rather than increases). ). The synthetic resin container lid 2 as described above is applied to a container provided with a neck portion 42 having the shape shown in FIG. The neck portion 42, which is known per se, has a cylindrical outer circumferential surface with a male thread 44 and a locking jaw 46 located below the male thread 44.
is formed. When closing the neck part 42 with the container lid 2, the container lid 2 is fitted onto the mouth neck part 42, and the container lid 2 is rotated in the closing direction, that is, clockwise when viewed from above in FIG. In this way, the female thread 24 formed on the container lid 2 is screwed into the male thread 44 formed on the neck part 42, and thereby the container lid 2 is moved downward in the axial direction as it rotates. . When the container lid 2 is moved downward, each of the locking flap pieces 28 formed on the container lid 2 passes through a male thread 44 formed in the neck portion 42 and then through the locking jaws. 46, but when passing through the locking jaw 46, the locking flap piece 2 is interfered with by the locking jaw 46.
8 are elastically deflected radially outward.
Connect the female thread 24 of the container lid 2 to the male thread 44 of the neck part 42.
When fully screwed together, each of the locking flap pieces 28 engages with the locking jaw 46, as shown in FIG.
, the locking flap pieces 28 are no longer interfered with by the locking jaws 46, and each of the locking flap pieces 28 elastically returns to its original state. Therefore, as will be clearly understood from the description of Examples and Comparative Examples to be mentioned later, in the container lid 2 constructed according to the present invention, the locking flap piece 28
The necessary downward rotational torque that must be applied to the container lid 2 when the container lid 2 is elastically deflected and forced to pass through the locking jaw 46 is determined by the locking flap having the configuration shown in phantom lines in FIGS. 2 and 3. The required downward rotational torque in conventional container lids with a tab is considerably reduced. Therefore, the mouth and neck region 42
It is reliably avoided that excessive stress is generated in the weakened lines 12 and 22 and that the weakened lines 12 and 22 break when the container lid 2 is attached to the container. When each of the locking flap pieces 28 has been fully restored to its original state, each of the locking flap pieces 28 has moved back into the locking jaw 46, as shown in FIG.
It is locked to the bottom surface of the. In addition, when the female thread 24 of the container lid 2 is fully screwed into the male thread 44 of the neck part 42, the sealing liner 10 is brought into close contact with the end surface of the neck part 42, as shown in FIG. The mouth and neck region 42 is thus sealed. The container lid 2 attached to the mouth and neck part 42 as described above is detached from the mouth and neck part 42 and the mouth and neck part 42 is removed.
When opening the container lid 2, the container lid 2 is rotated in a direction opposite to the direction of rotation when it is attached, that is, in a counterclockwise direction when viewed from above in FIG. In this way, since the female thread 24 formed on the container lid 2 is moved along the male thread 44 formed on the neck portion 42, the container lid 2 does not move upward in the axial direction. However, the locking flap piece 28 formed on the inner surface of the pilfer flap hem 16 of the container lid 2 does not fit the locking jaw portion 46 of the neck portion 42.
Since it is locked to the lower surface of the pilfer jacket, upward movement of the pilfer jacket hem 16 in the axial direction is prevented. In this way, considerable stress is generated in the weakened line 12 formed in the container lid 2, and the bridge portion 20 at the weakened line 12 is a specific bridge portion 20A having a large circumferential width and increased strength.
, and a considerable stress is also generated in the weakened line 22 formed in the pilfer blue hem 16, causing the weakened line 22 to break and change the pilfer blue hem 16 from an endless ring to an end. Opened in strips. In this way, the locking jaw portion 4
After the locking of the locking flap piece 28 to the lower surface of the flap 6 is released, the pilfer roof connected to the main portion 1 by the specific bridge portion 20A, which is maintained without being broken, is released. Hem 16
The entire container lid 2 including the container lid 2 is rotated and moved upward in the axial direction, and thus the entire container lid 2 is separated from the neck portion 42 and the neck portion 42 is opened (the above-mentioned specific bridge in the weakened line 12 Part 2
0A also has substantially the same strength as the other bridge parts 20, and there is a weakened line 2 at the hem part 16 of the pilfer blue.
2 is not formed, the weakened line 12 is completely broken and the pilfer blob hem 16 is completely separated from the main part 14, thus leaving the pilfer bluf hem 16 and the rest of the container lid 2. portion is detached from the mouth and neck region 42). As will be clearly understood from the description of Examples and Comparative Examples to be mentioned later, when the container lid 2 is removed from the mouth and neck part 42, the procedure is as shown by the two-dot chain line in FIGS. 2 and 3. In the container lid 2 constructed in accordance with the present invention, the locking flap piece 28 locks considerably more strongly against the underside of the locking jaw 46 than in conventional container lids having a flap piece in the form of . In other words, the necessary upward rotational torque that must be applied to the container lid 2 when the locking flap piece 28 is elastically deflected and passed through the locking jaw 46 from below in the axial direction to above is limited by the present invention. In the container lid 2 constructed according to the above, the capacity is considerably increased compared to conventional container lids. Therefore, the break lines 12 and 22 are not broken as expected and the mouth and neck area 4
It is reliably avoided that the container lid 2 is detached from the container lid 2, thus ensuring the pilferable roof properties. 5 and 6 illustrate a modification of the locking flap piece. In the locking flap piece 128 shown in FIGS. 5 and 6, both the lower edge 138 and the upper edge 140 of the locking flap piece 128 are not smooth curves in the bottom view, that is, in FIG.
Each is defined by six interconnected straight lines 138a to 138f and 140a to 140f. The radially inner surface 136 (and radially outer surface) of the locking flap piece 128 is
It is defined by five planes 136a to 136f that are connected and inclined in a predetermined direction. Importantly, each of the six straight lines 140a-140f defining the upper edge 140 is longer than each of the corresponding six straight lines 138a-138f defining the lower edge 138, respectively. 5 straight lines 1
When each of 40a to 140e becomes shorter than each of the five straight lines 138a to 138e, the twisting direction of the locking flap piece 128 is reversed, and the locking flap piece 128 is The radially outer surface appears instead of the radially inner surface 136 (and in such a case, the required downward rotational torque described above increases rather than decreases, and the required upward rotational torque described above decreases rather than increases). ). FIGS. 7 and 8 illustrate further modifications of the locking flap piece. The locking flap piece 228 illustrated in FIG. 7 and FIG. The radially inner surface 236 (and the radially outer surface) of the piece 228 is a helically curved surface. <Example> Using polypropylene (melt index 2.0, density 0.90), the main body of the container lid 2 shown in FIGS. 1 to 3 except that the weakening line 12 and the weakening line 22 are not formed. Ten container lid bodies having substantially the same form as the above were molded. The inner diameter of the female thread d of the molded container lid body was 25.6 mm, the outer diameter of the upper part D was 30.0 mm, and the total height H was 19.0 mm. Also,
Each of the locking flap pieces formed on the inner surface of the hem of the pilfer jacket has a thickness t=0.35.
mm, the distance between the free end of the upper edge and the inner surface of the hem of the pilfer roof, d ₁ = 2.2 mm, the distance between the free end of the lower edge and the inner surface of the hem of the pilfer roof, d ₂ = 1.2 mm, the upper edge is shown in the bottom view. Arc with radius 5.5mm (arc length 3.1
mm), and the lower edge was an arc with a radius of 4.5 mm (arc length 2.1 mm) in the bottom view. Such a container lid was attached to the mouth and neck of a glass container having a nominal diameter of 28 mm in the form shown in FIG. 4, and the required rotational torque at this time, that is, the required downward rotational torque was measured. In addition, the container lid attached to the mouth and neck was forcibly removed from the mouth and neck, and the required rotational torque at this time, ie, the required upward rotational torque, was measured.
The results were as shown in Table 1 below. <Comparative Example> For comparison, each of the locking flap pieces formed on the inner surface of the hem of the pilfer jacket was of the form shown by the two-dot chain line in FIGS. 2 and 3. Ten container lid bodies similar to those in the example were formed. Then, the required downward rotational torque and the required upward rotational torque were measured in the same manner as in the example. The results were as shown in Table 1 below.

[Table] <Effects of the Invention> As clearly understood from the experimental values in the above Examples and Comparative Examples, the container lid of the present invention has the advantage of lowering the required lowering rate when lowering the container lid relative to the mouth and neck of the container. The rotational torque is reduced and the required upward rotational torque for raising the container relative to the container neck is increased, so that a sufficient difference is created between the required downward rotational torque and the required upward rotational torque. Thus, the occurrence of inconveniences such as the weakened line being broken when the container lid is attached to the mouth and neck, or the container lid being removed from the mouth and neck without breaking the weakened line, can be reliably avoided.

[Brief explanation of the drawing]

FIG. 1 is a side view, partially in cross section, of a specific example of a container lid constructed in accordance with the present invention. 2 is a partial perspective view showing the locking flap piece of the container lid of FIG. 1; FIG. 3 is a partial bottom view showing the locking flap piece of the container lid of FIG. 1; FIG. Figure 4 shows
FIG. 2 is a side view, partially in section, showing a state in which the container lid of FIG. 1 is attached to the mouth and neck of the container to close the mouth and neck. FIG. 5 is a partial perspective view showing a modification of the locking flap piece. FIG. 6 is a partial bottom view showing the locking flap piece of FIG. 5. FIG. 7 is a partial perspective view showing still another modification of the locking flap piece. FIG. 8 is a partial bottom view showing the locking flap piece of FIG. 7. 2... Container lid, 4... Top wall, 6... Skirt wall, 1
2... Weakening line, 14... Main part of skirt wall, 16
...Pilfer blue hem, 24...Female thread, 2
8, 128 and 228...locking flap pieces, 42...
Mouth and neck portion, 44...male thread, 46...locking jaw portion.

Claims (1)

[Scope of Claims] 1. A composition having pilfer-blue characteristics for a container having a neck portion in which a male thread and a locking jaw portion located below the male thread are formed on the outer peripheral surface. The container lid is made of resin and includes a top wall and a cylindrical skirt wall that hangs down from the periphery of the top wall, the skirt wall is formed with a weakened line extending in the circumferential direction, and the skirt wall is It is divided into a main part above the weakened line and a hem part below the weakened line, and the inner surface of the main part has a female thread that is screwed into the male thread of the mouth and neck part. A plurality of screw threads are formed on the inner surface of the hem of the pill fur valve, and a plurality of screw threads are formed on the inner surface of the hem of the pill fur valve, and the threads are inclined in a direction opposite to the direction of rotation of the container lid when the container lid is attached to the mouth and neck, and protrude radially inward. In a container lid in which locking flap pieces are formed at intervals in the circumferential direction; at least a portion of each of the locking flap pieces
A container lid characterized by having a shape in which the upper part is twisted inward in the radial direction than the lower part. 2. In at least a portion of each of the locking flap pieces, the lower edge and the upper edge are curved in a bottom view, and the radius of curvature of the curve of the lower edge is greater than the radius of curvature of the curve of the upper edge. Small Claim 1
Container lid as described in section. 3. At least a portion of each of the locking flap pieces has a shape in which a plurality of planes are relatively inclined in a predetermined direction and connected, and the upper edge of each of the plurality of planes is longer than the lower edge. , a container lid according to claim 1. 4. The container lid according to claim 1, wherein at least a portion of each of the locking flap pieces is a spirally curved surface.