JP2811496B2 - Combination of container and lid - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a combination of a container and a lid, and more specifically, a sealing member made of foamed plastic pressed against the top surface of the mouth and neck of the container is provided on the inner surface of the top wall of the lid. The present invention relates to a combination of a container and a lid in a form provided.

(Prior art)

As a combination of a container and a lid suitable for alcoholic beverages such as sake and whiskey, a container having a cylindrical mouth and neck,
A combination with a lid attached to the mouth and neck of a container is widely used. The container is generally formed from glass or any suitable non-foamed plastic. An external thread is formed on the outer peripheral surface of the mouth and neck of such a container. The lid is made of a suitable non-foamed plastic or a suitable metal. Such a lid has a top wall and a cylindrical skirt wall hanging from the periphery of the top wall. On the inner surface of the skirt wall, a female thread is formed which is screwed into a male thread formed on the mouth and neck of the container. On the inner surface of the top wall, a sealing member made of foamed plastic, which may be circular or annular, is provided.
The sealing member is pressed against the top of the mouth and neck of the container, thus sealing the mouth and neck.

[Problems of the prior art]

As a result of conducting various experiments and analyzes on the conventional combination as described above, it was found that the conventional combination had the following problems.

In the content filling factory, after filling the contents of the container such as alcoholic beverages, cover the mouth and neck of the container,
For example, in the case of a lid having an outer diameter of 30 mm, the lid is attached to the mouth and neck with a tightening torque of about 22 kg · cm (the female thread of the skirt is screwed into the male thread of the mouth and neck). Thus, the sealing member arranged on the inner surface of the top wall of the lid is pressed against the top surface of the mouth and neck, and the mouth and neck are sealed. Containers filled with contents and fitted with a lid are housed in a case for transportation,
Then, they are stacked vertically with a pallet in between. In this case, the top of the bottom
A so-called loading load of about 50 to 80 kg is often applied.

In the conventional combination of a container and a lid, when the above-mentioned load is applied in addition to the initial tightening torque at the time of mounting the lid, excessive stress is generated in the foamed plastic sealing member, and the sealing member is excessively compressed. Be transformed. And
When the above-described vertical stacking is released, for a relatively short time, the pressing force of the sealing member against the top surface of the mouth and neck portion is excessively reduced, and as a result, the sealing of the mouth and neck portion is damaged. Will be done. When the pressing force of the sealing member against the top surface of the mouth and neck is excessively reduced, for example, when the container is laid down, leakage of the contents may occur.
(Such problems in the conventional combination will be further described later.) [Problems of the Invention] The present invention has been made in view of the above-mentioned facts. Even when a load is applied, the pressing force of the sealing member against the mouth and neck is reliably prevented from being excessively reduced, and thus the sealing of the mouth and neck is prevented from being damaged due to the loaded load. That is.

[Solution of the Invention]

In order to achieve the above technical solution, a solution of the present invention is to provide a female screw thread formed on the inner peripheral surface of the lid skirt wall with a male screw thread formed on the outer peripheral surface of the mouth and neck of the container. In a state in which the upper surface of the female thread is brought into contact with the lower surface of the externally threaded thread, the minimum axial distance d between the lower surface of the internal thread and the upper surface of the external thread is set to 0.1 to 0.4 mm.

That is, according to the present invention, there is provided a container having a cylindrical mouth-neck portion, an outer peripheral surface of the mouth-neck portion having an external thread formed thereon, a top wall, and a cylindrical skirt wall hanging down from the periphery of the top wall. A female screw thread is formed on the inner peripheral surface of the skirt wall to be screwed with the male screw thread, and a sealing member made of a foamed plastic pressed against the top surface of the mouth and neck portion is formed on the inner surface of the top wall. In combination with the lid where is arranged,
In a state where the female thread is screwed into the male thread and the upper face of the female thread is brought into contact with the lower face of the male thread, the minimum axial distance d between the lower face of the female thread and the upper face of the male thread is 0.1 to A combination characterized by being set to 0.4 mm is provided.

The top and skirt walls of the lid in the combination of the present invention can be formed from any suitable non-foamed plastic.
In order to reduce or avoid an increase in the consumption of the non-foamed plastic material used for molding the lid by adopting the above solution of the present invention, if necessary, the inner surface of the lid skirt is formed. It is possible to form a groove extending continuously in the width direction at the widthwise intermediate portion of the female screw thread to be formed, or to form a plurality of protrusions projecting downward from the lower surface of the female screw thread at circumferential intervals. it can.

[Function of the invention]

In the combination of the present invention, the external thread formed on the outer peripheral surface of the mouth and neck of the container is screwed with the internal thread formed on the inner peripheral surface of the lid skirt wall, and the lower surface of the external thread is screwed on the lower surface of the external thread. In the state where the surface was touched,
The minimum distance d in the axial direction between the lower surface of the internal thread and the upper surface of the external thread is set to be considerably smaller than that of the conventional combination. Therefore, when the above-mentioned load is applied to the upper surface of the lid, when the compression of the foamed plastic sealing member is increased due to the load, the lid is lowered in the axial direction with respect to the mouth and neck of the container, and the lid is closed. The lower surface of the female thread formed on the skirt wall is brought into contact with the upper surface of the external thread formed on the mouth and neck of the container. Thus, the load applied to the upper surface of the lid is transmitted from the female thread of the skirt wall to the male thread of the mouth and neck, and is supported by the mouth and neck of the container, thereby preventing the stress of the sealing member from further increasing. . In this way, excessive stress is generated in the sealing member, and it is ensured that excessive compression deformation of the sealing member is avoided. Therefore, even when the loading load is applied to the upper surface of the lid, the pressing force of the seal member against the mouth and neck is reliably prevented from excessively decreasing, and the sealing of the mouth and neck is damaged due to the loading load. Is reliably avoided.

[Specific examples of the invention]

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

Referring to FIG. 1, the illustrated combination constructed in accordance with the present invention comprises a combination of a container 2 (only a portion of which is shown) and a lid 4 mounted on the container 2. The container 2, which can be made of a suitable non-foamed plastic such as glass or polyethylene terephthalate (PET), has a substantially cylindrical mouth and neck 6 at its upper end. An external thread 8 is formed on the outer peripheral surface of the mouth and neck portion 6. The lid 4 has a circular top wall 10 and this top wall 10
Has a cylindrical skirt wall 12 depending from the periphery of the skirt wall.
A female thread 14 is formed on the inner peripheral surface of the skirt wall 12. The top wall 10, the skirt wall 12, and the internal thread 14 on the inner peripheral surface of the skirt wall 12 of the lid 4 can be integrally formed by injection or compression molding from a suitable non-foamed plastic such as polypropylene or polyethylene. If desired, the top wall 10 of the lid 4, the skirt wall 12, and the internal threads 14 of the inner peripheral surface of the skirt wall 12 can be formed from any suitable metal, such as aluminum or tinplate. A circular seal member 16 is provided on the inner surface of the top wall 10 of the lid 4. The sealing member 16 can be formed in a required shape from a suitable foamed plastic such as foamed polyethylene separately from the lid body, and can be inserted into the inner peripheral surface of the top wall 10 of the lid 4. Instead of the circular seal member 16, an annular seal member can be used. If desired, an unfoamed plastic material can be applied to the inner surface of the top wall 10 of the lid 4 and the plastic material can be foamed on the inner surface of the top wall 10.

The container 2 is filled with required contents such as alcoholic beverages, and then the lid 4 is attached to the mouth and neck 6. In order to attach the lid 4, the lid 4 is fitted to the mouth and neck 6, and a required tightening torque (for example, approximately 22 kg when the outer diameter of the lid 4 is 30 mm)
The cover 4 is rotated clockwise as viewed from above in FIG.
The internal thread 14 formed on the inner peripheral surface of the screw 12 is screwed into the external thread 8 formed on the outer peripheral surface of the mouth and neck portion 6. Thus, as clearly shown in FIG. 1, the sealing member 16 is pressed against the top surface of the mouth and neck 6 and is compressed between the top wall 10 of the lid 4 and the top surface of the mouth and neck 6. Thus,
The mouth and neck 6 are sufficiently sealed. Since the sealing member 16 is compressed between the top wall 10 of the lid 4 and the top surface of the mouth and neck 6, an upward force in the axial direction acts on the top wall 10 of the lid 4 from the sealing member 16. Therefore, the upper surface of the internal thread 14 formed on the inner peripheral surface of the skirt wall 12 is brought into contact with the lower surface of the external thread 8 formed on the outer peripheral surface of the mouth and neck portion 6.

Thus, the above-described configuration in the illustrated combination is already known, and does not constitute a new configuration improved by the present invention. In the present invention, the upper surface of the female thread 14 formed on the inner peripheral surface of the skirt wall 12 of the lid 4 is mounted on the mouth and neck 6 of the container 2 as required, as shown in FIG. Is in contact with the lower surface of the external thread 8 formed on the outer peripheral surface of the mouth-and-neck portion 6 of the container 2, the minimum axial distance d between the lower surface of the external thread 14 and the upper surface of the external thread 8 is the conventional value. It is important that it is set to 0.1 to 0.4 mm, which is much smaller than the one.

In the conventional combination, as shown in FIG. 2, a lid 104 is attached to the mouth and neck 106 of the container 102 as required, and
Female thread 114 formed on the inner peripheral surface of the skirt wall 112
Is in contact with the lower surface of the external thread 108 formed on the outer peripheral surface of the mouth-neck portion 106 of the container 102, the minimum axial distance d between the lower surface of the internal thread 114 and the upper surface of the external thread 108 is It is quite large and 0.6 mm or more, usually 0.8 to
It was about 1.6 mm. In such a case, as will be described in more detail below, when a load is applied to the upper surface of the lid 104, the seal of the cervix 106 may be damaged.

On the other hand, if the minimum distance d in the axial direction is excessively reduced to be smaller than 0.1, the external thread 8 of the mouth and neck 6 and the internal thread 14 of the skirt wall 12 are mutually displaced when the lid 4 is attached to the mouth and neck 6. , There is a tendency that a smooth screwing of the two and thus a smooth mounting is hindered.

Referring to FIG. 3 together with FIG. 1 and FIG. 2, as already mentioned, the container 2 is used in the content filling factory.
The inside is filled with contents such as alcoholic beverages, and then the lid 4 is attached to the mouth and neck 6 with a required tightening torque. FIG. 3 is a diagram showing the stress and the compressive strain acting on the foamed plastic sealing member 16 in the lid with the vertical axis and the horizontal axis respectively. In FIG. 3, the solid line A shows the stress and the compressive strain of the sealing member 16 made of the foamed plastic when the lid 4 is attached to the mouth and neck 6 of the container 2 with a required tightening torque. This slight decrease in the stress at the end of the solid line A is due to permanent strain generated in the seal member 16 with time after the lid 4 is mounted.

After the contents such as alcoholic beverages are filled in the container 2 and the lid 4 is mounted on the mouth and neck 6 with a required tightening torque, the container 2 with the lid 4 is usually housed in a case, and Several tiers are stacked vertically with a pallet in between. Then, they are loaded on a truck or the like for transportation. In this case, a loading load of about 50 to 80 kg per one is applied to the upper surface of the lid 4 of the lowermost container 2. When the above-mentioned load is additionally applied to the upper surface of the lid 4, the stress and strain of the seal member 16 further change.

As shown by a two-dot chain line in FIG. 2, in the conventional combination, the above-mentioned loaded load acts on the seal member 116 as it is, continuously compressing the seal member 116 and lowering the lid 104 in the axial direction. The stress and strain of 116 continue to increase as shown by the two-dot chain line B and reach a considerably large value.
At the end of the two-dot chain line B, the stress does not change due to the permanent set of the seal member 116 over time, but only the strain changes. When the transportation is completed and the stacking is released, the loading load is released. Then, the lid 104 rises again and returns to the state shown by the solid line in FIG. On the other hand, the stress and the compressive strain of the seal member 116 change as shown by a two-dot chain line C in FIG. That is, both the stress and the compressive strain of the seal member 116 are initially reduced, and then the strain is further reduced, but the stress rises somewhat due to the elastic restoring action of the seal member 116. However, in the conventional combination, the stress of the sealing member 116 exceeds the K value which is an allowable value for a relatively short time after the loading load is released. If the stress of the sealing member 116 exceeds the K value, the pressing force of the sealing member 116 against the top surface of the mouth and neck 106 becomes excessively small, the seal of the mouth and neck 106 is damaged, and the container 102 is laid down. And the contents will leak.

On the other hand, in the combination improved by the present invention, when the sealing member 16 is further compressed somewhat by the above-mentioned load and the lid 4 is lowered downward in the axial direction,
As shown by a two-dot chain line in FIG. 1, the lower surface of the female thread 14 formed on the inner peripheral surface of the skirt wall 12 of the lid 4 is formed on the outer peripheral surface of the mouth and neck 6 of the container 2. It is brought into contact with the upper surface. Thus, the above load is applied to the skirt wall.
The twelve female threads 14 are directly transmitted and supported from the twelve female threads 8 to the male and female threads 8 of the mouth and neck part 6, and the load on the sealing member 16 is stopped. Accordingly, the increase in the stress and the compressive strain of the seal member 16 is stopped at a considerably lower value than the conventional case, as shown by the solid line B in FIG. When the stacking is released after the transportation is completed and the load is released, the lid 4 rises again and returns to the state shown by the solid line in FIG. At this time, the stress and the compressive strain of the seal member 16 change as shown by a solid line C in FIG. That is, both the stress and compressive strain of the seal member 16 are initially reduced, and then the strain is further reduced, but the stress increases somewhat due to the elastic restoring action of the seal member 16. Thus, in the combination improved by the present invention, since the minimum value of the stress acting on the seal member 16 is limited to a considerably higher value than in the conventional case, the reduction in the stress of the seal member 16 is reduced. The value is limited to a considerably higher value than in the case, and the minimum value of the stress is kept at a value much higher than in the conventional case. Thus, the sealing member 16
Is prevented from exceeding the allowable value K.

4 and 5 show a modification of the combination constructed according to the present invention. As can be easily understood by comparing FIGS. 1 and 2, the width of the internal thread 14 formed on the inner peripheral surface of the skirt wall 12 of the lid 4 is improved in order to make the above-mentioned improvement according to the present invention. Is increased, the lid 4
The amount of plastic material used to mold the material is considerably increased. In the modification shown in FIG. 4, in order to reduce or avoid the increase in the amount of plastic material used, a groove 18 extending continuously in the thread direction is formed at the widthwise intermediate portion of the internal thread 14. I have. In the modification shown in FIG. 5, a plurality of projections 20 projecting downward at intervals in the circumferential direction are formed on the lower surface of the female screw thread 14, and such projections 20 are formed.
Is set to 0.1 to 0.4 mm in the axial direction between the lower surface of the upper surface and the upper surface of the external thread 8 (FIG. 1) of the mouth and neck 6.

In the above-described specific example, the skirt wall of the lid 4 is set in order to set the minimum distance d in the axial direction to a required range.
The female thread 14 formed on the inner peripheral surface of the container 12 is modified, but if desired, the external thread 8 formed on the outer peripheral surface of the mouth and neck 6 of the container 2 may be alternatively or additionally provided. Deformations can also be made.

(Examples and Comparative Examples)

Example 1 A combination of a container and a lid as shown in FIG. 1 was produced. The container was made of glass, the top wall of the lid, the skirt wall and its internal thread were made of polypropylene, and the sealing member was made of expanded polyethylene having an expansion ratio of 2 times. The outer diameter of the lid was 30 mm, and the thickness of both the top wall and the skirt wall of the lid was 1.5 mm. Both the height of the internal thread and the height of the external thread were 1 mm.

Store the water colored in red in the container and tighten the tightening torque.
At 22 kg · cm, a lid was attached to the mouth and neck of the container. The minimum axial distance d between the lower surface of the internal thread formed on the inner peripheral surface of the skirt wall of the lid and the upper surface of the external thread formed on the outer peripheral surface of the mouth and neck of the container was 0.1 mm. An 80 kg weight was placed on the top of the lid for 24 hours, after which the weight was removed and the vessel was laid down for 10 minutes. Then, the presence or absence of water leakage was inspected by adhering red colored water to the blotting paper wound around a specific portion of the mouth and neck of the container (immediately below the skirt wall of the lid). The occurrence of leakage was zero as shown in Table 1 below for 100 combinations.

Example 2 A similar combination as in Example 1 was made except that the minimum distance d in the axial direction was 0.2 mm, and a similar leak test was performed. For the combination of 100 pieces, the first
It was zero as shown in the table.

Example 3 A combination similar to that of Example 1 was prepared except that the minimum distance d in the axial direction was 0.3 mm, and a similar leak test was performed. For the combination of 100 pieces, the first
There were two as shown in the table.

Example 4 A combination similar to that of Example 1 was prepared except that the minimum distance d in the axial direction was 0.4 mm, and a similar leak test was performed. For the combination of 100 pieces, the first
There were four as shown in the table.

Comparative Example For comparison, a combination similar to that of Example 1 was prepared except that the minimum distance d in the axial direction was 0.6 mm, and a similar leak test was performed. As shown in Table 1 below, 30 leaks occurred for 100 combinations.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a preferred embodiment of an improved combination according to the present invention. FIG. 2 is a cross-sectional view illustrating a conventional combination. FIG. 3 is a diagram showing changes in stress and strain of a seal member in the combination shown in FIGS. 1 and 2; FIG. 4 and FIG. 5 are cross-sectional views showing a modification of the female screw thread formed on the inner peripheral surface of the skirt wall of the lid. 2 ... container 4 ... lid 6 ... mouth and neck 8 ... male thread 10 ... top wall 12 ... skirt wall 14 ... female thread 16 ... sealing member

Claims (4)

(57) [Claims] 1. A container having a cylindrical mouth and neck, a container having an external thread formed on an outer peripheral surface of the mouth and neck, a top wall and a cylindrical skirt wall hanging down from a periphery of the top wall, On the inner peripheral surface of the skirt wall, a female screw thread to be screwed with the male screw thread is formed, and on the inner surface of the top wall, a sealing member made of foamed plastic pressed against the top surface of the mouth and neck portion is provided. When the female thread is screwed into the male thread and the upper face of the female thread is brought into contact with the lower face of the male thread, the lower face of the female thread and the upper face of the male thread are Is the minimum distance d in the axial direction of
A combination characterized by being set to 0.1 to 0.4 mm. 2. The combination of claim 1, wherein said top wall and said skirt wall of said lid are made of non-foamed plastic. 3. The combination according to claim 2, wherein the female screw thread is formed with a groove extending continuously in the thread direction at an intermediate portion in the width direction. 4. A plurality of projections projecting downward from the lower surface of the female screw thread at intervals in a circumferential direction.
A combination according to claim 2.