JPH02191163A - Metal container lid with pilfer proof property - Google Patents

Abstract

PURPOSE:To avoid generating a sharp remaining part after fracture by a method wherein on the majority of bridges among a plurality of bridges, bending to generate fracture is applied along the upper end edges. CONSTITUTION:At the position of a slit 16 on a weakened line 10, cutting is applied on an annular projected part 8, and the slit 16 is provided by the cutting. In the meantime, at the position of a bridge part 18 (excepting a wide bridge part 18a) on the weakened line 10, a bend with a bending angle alpha is generated along an upper end edge 30 of the bridge part 18 by applying bending along the upper end edge 30 of the bridge part 18. For the bending angle alpha, 120-170 deg. is desirable. When the bending angle alpha is smaller, the strength of the bridge part 18 becomes smaller. On the contrary, when the bending angle alpha is larger, the purpose to give fracture to the bridge part 18 along the upper end edge can not be assuredly achieved. On the bridge parts 18, which should be fractured at the time of opening, a bend has been formed, and the bridge parts 18 are fractured in a straight line along the upper end edge 30. Thus the generating of remaining parts after fracture, which protrude downward from a main part 12 of a skirt wall 6, can be avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention comprises a metal container lid having pilfer-proof properties, and more particularly, a top wall and a cylindrical skirt wall depending from the periphery of the top wall, The present invention relates to a metal container lid in which a weakened line is provided in the skirt wall, the weakening line consisting of a plurality of slits extending in the circumferential direction at intervals in the circumferential direction and a plurality of bridge portions located between the slits. .

[Prior art]

As is well known, metal container lids having pilfer-proof properties are widely used as container lids for containers such as glass or synthetic resin bottles for beverages and the like.

The container lid, which is formed from a thin metal sheet such as a thin aluminum foil, a chromic acid-treated steel sheet, or a thin tin plate, includes a top wall and a cylindrical skirt wall depending from the periphery of the top wall. The skirt wall is provided with a weakened line extending in the circumferential direction, and the skirt wall is divided into a main portion above the weakened line and a pilfer-proof hem portion below the weakened line. The weakened line is composed of a plurality of slits extending in the circumferential direction at intervals in the circumferential direction and a plurality of bridge portions located between the slits.

The inner surface of the top wall is typically provided with a sealing liner made of a suitable synthetic resin.

The container lid described above is applied to a container in which a male thread and a locking jaw located below the male thread are formed on the outer peripheral surface of the mouth and neck. When attaching a container lid to the mouth and neck of a container to seal the mouth and neck, the container lid is fitted onto the mouth and neck, and pressing force is applied to the outer surface of the top wall of the container lid to seal the sealing liner to the upper end of the mouth and neck. Close to. And while maintaining this state,
A female thread is formed in the main part of the skirt wall of the container lid along the female thread of the mouth and neck, and the lower end of the skirt wall of the container lid, that is, the lower end of the pilfer-proof hem is bent inward. and lock it in the locking jaw at the mouth and neck.

When opening the neck of the container, the container lid is rotated in the opening direction. In this way, the female thread of the container lid moves along the male thread of the mouth and neck, thus raising the container lid relative to the mouth and neck.

However, since the pilfer-proof hem of the container lid is locked to the locking jaws of the mouth and neck, it is prevented from rising, and thus considerable stress is generated in the weakened line, more specifically in its bridging area, and multiple (in some forms of container closures, all bridges are broken to completely separate the pilfer-proof hem from the main portion of the skirt wall; In other forms of container lids, there are one or several wide bridges with a relatively large circumferential width, and normal bridges other than the wide bridges are broken, and the pill is also broken. A break line extending in the axial direction is formed on the fur-proof hem, and the break line is broken to open the pilfer-proof hem from an endless ring shape to an end band shape. The container lid is removed from the mouth and neck of the container, leaving the hem at the neck and the mouth of the container, or including the pilfer-proof hem,
The mouth and neck are opened.

[Problems with conventional technology]

However, in the conventional container lid of the above configuration, when the bridging portion is broken when opening the neck of the container, a sharp broken portion is generated that protrudes downward from the main portion of the container lid. There are issues to be addressed. If a consumer's finger accidentally comes into contact with the sharp breakage after opening, there is a high risk of damage.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned facts, and its main purpose is to improve the structure so that it is possible to substantially avoid the generation of the sharp breakage residue due to the breakage of the bridge portion.

[Means for solving the invention]

As a result of intensive research and experiments, the inventors have found that when bending the bridge portion along the upper edge, fractures at the end of the bridge are generated along the upper edge of the bridge, thus causing the container It has been found that the formation of sharp breakage residues projecting downwardly from the main part of the lid can be substantially avoided.

That is, the present invention includes a top wall and a cylindrical skirt wall that hangs down from the periphery of the top wall, the skirt wall is provided with a weakened line extending in the circumferential direction, and the skirt wall is provided with a weakened line extending in the circumferential direction. The wall is divided into a main portion above the weakened line and a pilfer-proof hem below the weakened line, and the weakened line includes a plurality of slits extending circumferentially at intervals in the circumferential direction. In a metal container lid having a pilfer-proof property and comprising a plurality of bridge sections located between the slits, at least a majority of the bridge sections have an upper end thereof. Container lids are provided, characterized in that they are bent along their upper edges to create a break along the edge.

120 degrees to 170 degrees by bending
In particular, it is preferable to bend the bridge portions along their upper edges at a bending angle α of 130 degrees to 160 degrees. If the bending angle α is too small, in other words, if the degree of bending is too high, the strength of the bridge will be too low.
When attaching the container lid to the neck of the container, there is a tendency for the bridging portion to break. If the bending angle α is too large, in other words if the degree of bending that is applied is too low, the fracture of the bridge will not occur with sufficient certainty along the upper edge.

In a container lid in which the plurality of bridging portions include a wide bridging portion having a relatively wide circumferential width, the wide bridging portion is not subjected to the above bending process, and the wide bridging portion is It is desirable to completely avoid strength loss.

Incidentally, the inventors of the present invention initially conducted various experiments by forming so-called scores generated by reducing the material wall thickness by a considerable amount instead of bending the bridge portion, but such In such cases, the strength of the bridge was significantly reduced, and there was a significant tendency for the bridge to break when the container lid was attached to the neck and neck of the container.

[Preferred specific example]

BRIEF DESCRIPTION OF THE DRAWINGS Reference will now be made in further detail to the accompanying drawings, which illustrate preferred embodiments of container closures constructed in accordance with the present invention.

Referring to FIG. 1, the illustrated container lid 2, which can be formed from a suitable metal sheet such as an aluminum-based alloy sheet or a chromic acid treated steel sheet, includes a circular top wall 4 and a peripheral edge of the top wall 4. and a cylindrical skirt wall 6 depending from the cylindrical skirt wall 6. In the lower part of the skirt wall 6 there is an annular portion 8 which is somewhat bulged in the radial direction, and a weakened line IO extending in the circumferential direction is formed in the annular bulge portion 8 .

This weakened line 10 extends the skirt wall 6 between the main part 12 above it and the pilfer-proof hem 14 below it.
It is divided into The weakened line 10 is composed of a plurality of slits 16 extending in the circumferential direction at intervals in the circumferential direction, and a plurality of bridge portions 18 located between the slits 16. A specific one of the plurality of bridge parts 18
This is made into a wide bridging portion 18a having a larger width in the circumferential direction than the other bridging portions 18. Main part 1 of skirt wall 6
An anti-slip uneven portion 20 is formed at the upper end portion of 2. Further, below this uneven portion 20,
An annular groove portion 22 is formed.

The pilfer-proof hem 14 of the skirt wall 6 is connected to the pilfer-proof hem 1 from one end of the wide bridging portion 18a.
An axial break line 24 is formed that extends downwardly to the lower end of 4. This breaking line 24 may be a so-called score formed by reducing the material thickness.A sealing liner 26 that can be molded from a suitable synthetic resin is disposed on the inner surface of the top wall 4. There is. This sealing liner 26 has a disk shape as a whole, and an annular sealing portion 28 having two concentric sealing protrusions is formed at its peripheral edge.

The above-described configuration of the illustrated container M2 is already well known and does not constitute a novel feature improved in accordance with the present invention, and therefore a detailed explanation of such configuration will be omitted.

Continuing the explanation with reference to FIGS. 2 to 4 together with FIG. 1, at the portion of the slit 16 in the weakened line 10,
As shown in FIG. 2, the annular bulging portion 8 is cut, and a slit 16 is created by the cutting. On the other hand, the bridge portion 1B in the weakened line 10
Conventionally, the portion of the wide bridge portion 18a (excluding the wide bridge portion 18a) has not been subjected to any processing as shown by the two-dot chain line in FIG. It is important to create a bend at a bending angle α along the upper edge 30 of the bridge portion 18 by performing the bending process along the bending process. The above bending angle α is 120 degrees to 170 degrees,
In particular, if the bending angle α, which is preferably 130 degrees to 160 degrees, is excessively small, in other words, the degree of bending is excessively high, the strength of the bridge portion 18 will be insufficient. On the other hand, if the bending angle α is too large, in other words, the degree of bending is too small, the intended purpose of breaking the bridge portion 18 along its upper edge will be achieved with sufficient certainty. On the other hand, as shown in FIG. 4, the wide bridging portion 18a is preferably left as it is without being bent, as in the conventional case.

The above-mentioned bending process can be carried out at the same time as or subsequent to cutting the slit 14 by adding a processing tool for bending to a rotary processing device disclosed in Japanese Patent Publication No. 58-1520. can be carried out.

The container lid 2 constructed according to the invention is applied to the neck of the container as shown in FIG. The neck portion 32 of the container, which may be made of glass or a suitable synthetic resin, is approximately cylindrical, and its outer peripheral surface is formed with a female thread 34 and a locking jaw 36 located below the female thread 34. 0 mouth neck 3
In order to attach the container lid 2 to the container lid 2 and seal the neck part 32, as in the case of conventional container lids, the container lid 2 is fitted onto the mouth neck part 32, and the outer surface of the top wall 4 of the container lid 2 is sealed. A pressing force is applied to bring the annular sealing portion 28 of the sealing liner 26 into close contact with the upper end of the mouth and neck region 32 . Then, while maintaining this state, a female thread 38 is attached to the main part 12 of the skirt wall 6 of the container lid 2 along the male thread 34 of the neck part 32, more specifically, in a region below the annular groove part 22. form. In addition, the lower end of the pilfer-proof hem 14 is bent radially inward and engaged with the locking jaws 36 of the mouth and neck section 32.

In order to open the mouth part 32 of the container, the container lid 2 is rotated in the opening direction, that is, in the counterclockwise direction when viewed from above in FIG. In this way, the container lid 2 is raised as it rotates due to the cooperation of the male thread 34 and the female thread 38. However, since the pilfer-proof hem 14 is locked at its lower end by the locking jaws 36, it cannot rise freely, and thus the circumferentially extending weakened line 10 and the axial break line 24 Substantial stresses are generated.

Due to this stress, the fracture line 24 along with the bridge portion 18 excluding the wide bridge portion 18a at the weakened line IO
is broken, and as shown in FIG. 6, the endless annular pilfer-proof hem 14 is opened into an edged band shape. Thereafter, the entire container 12 is rotated and freely raised and separated from the neck part 32, and the neck part 32 is opened.

Therefore, in the conventional container lid, when the mouth and neck are opened, the bridge in the weakened line is broken in an unspecified shape at an unspecified location, and as shown in FIG. A sharp breakage remnant 40 protrudes downward from the main part of the skirt wall after
could not be prevented from being generated. If a consumer's finger or the like comes into contact with the sharp broken portion 40, there is a considerable risk that it will be damaged.

In the container lid 2 constructed according to the present invention, the bridging portions 18 that are to be broken when opening the neck portion 32 are bent along their upper edges 30, and therefore, As shown in FIG. 8 together with FIG. 6, the bridge portions 18 are fractured in a straight line along their upper edges 30, and a fractured remainder 40 protruding downward from the main portion 12 of the skirt wall 6 is sufficiently generated. definitely avoided.

〔Effect of the invention〕

As mentioned above, according to the invention, the bridges are broken in a straight line along their upper edges, so that due to the breakage of the bridges there is no downward protrusion from the main part of the skirt wall. The formation of sharp breakage residues is avoided with sufficient certainty, and damage to the consumer's fingers etc. is prevented.

[Brief explanation of the drawing]

FIG. 1 is a side view, partially in section, of a preferred embodiment of a container lid constructed in accordance with the present invention. 2, 3, and 4 are lines n-n in FIG. 1, respectively.
, mm and IV-IV. FIG. 5 is a side view, partially in section, showing a state in which the container lid of FIG. 1 is applied to the mouth and neck of the container to seal the mouth and neck. 6 is a side view showing the container lid of FIG. 5 removed from the mouth and neck of the container; FIG. 7 and 8 are partial side views showing the broken state of the bridge portion in the conventional container lid and the broken state of the bridge portion in the container lids of FIGS. 1 to 6, respectively. 2...Container lid 4...Top wall 6...Skirt wall 10...Weakening line 12...Skirt wall main portion 14...Pilfur proof hem 16...Slit 18... Bridge section 8a 24, 26, 30, 32, 40, Wide bridge section axial fracture line Sealing liner Upper edge of bridge section Sharp fracture remains at neck and neck of container (prior art) Fig. 5

Claims (1)

[Claims] 1. A top wall and a cylindrical skirt wall that hangs down from the periphery of the top wall, the skirt wall is provided with a weakened line extending in the circumferential direction, and the skirt The wall is divided into a main portion above the weakened line and a pilfer-proof hem below the weakened line, and the weakened line includes a plurality of slits extending circumferentially at intervals in the circumferential direction. In a metal container lid having a pilfer-proof property and comprising a plurality of bridge sections located between the slits, at least a majority of the bridge sections have an upper end thereof. Container lids characterized in that they are bent along their upper edges to produce breaks along the edges. 2. The container according to claim 1, wherein at least most of the plurality of bridges are bent at a bending angle α of 120 degrees to 170 degrees at their upper edges. lid. 3. The container lid according to claim 2, wherein the bending angle α is 130 degrees to 160 degrees. 4. At least one of the plurality of bridge portions is a wide bridge portion having a relatively large circumferential width, and the wide bridge portion is not subjected to the bending process. The container lid described in any of items 3 to 3 above.