Insect intrusion prevention cap

Abstract

Provided is a cap-equipped container comprising: a container having a cylindrical mouth / neck part and a bottom part, with a male screw thread formed on an outer peripheral surface of the mouth / neck part; and a cap attached to the mouth / neck part. The cap includes a top surface wall and a cylindrical skirt wall that hangs down from a peripheral edge of the top surface wall. A female screw thread, which is screwed to the male screw thread, is formed on an inner peripheral surface of the skirt wall. The cap-equipped container is characterized by the following. The male screw thread comprises one or more male screw projection strips. One male screw projection strip and a male screw projection strip adjacent to said one male screw projection strip have an overlap portion where both are present in an axial direction. A protruding part is formed in a portion of a recess between the one male screw projection strip and the adjacent male screw projection strip in the overlap portion. The female screw thread comprises at least one female screw projection strip. The female screw projection strip has a thick screw region in which a screw width becomes wider, and in a closed lid state, an upper surface of the thick screw region and a lower surface of the male screw projection strip positioned above the protruding part are brought into contact with each other.

Description

Insect prevention cap

[0001] The present invention relates to a capped container having an insect-proof function.

[0002] A widely used capped container for beverages is a container such as a glass bottle, which is fitted with a synthetic resin cap formed into a desired shape by injection molding the resin. When attaching the cap to the mouth of the container, some caps are fitted onto the mouth of the container by tapping, while others are attached by screwing the cap onto a threaded portion formed on the outer periphery of the cylindrical side wall of the mouth of the container and then seaming.

[0003] For example, Patent Document 1 proposes a composite cap consisting of a synthetic resin outer lid and a metal inner lid, and describes that the composite cap has a so-called guarantee characteristic that indicates that the container has been properly maintained in a reduced pressure state until it is opened, as well as a so-called pilfer-proof characteristic that indicates a trace of the cap being removed from the neck of the container once it has been removed. In a container equipped with such a cap, the hermeticity of the container is ensured by a liner (sealing material) formed on the metal inner lid.

[0004] However, in hot and humid climates such as Southeast Asia, when a cap is screwed onto a container and in a closed (unopened) state, depending on the storage environment of the container, there is a risk that tiny insects such as ants may invade the threaded portion, travel along the gap between the male thread formed on the container and the female thread formed on the cap, reach the resin seal inside the cap, and break through the seal, thereby invading the inside of the container. Furthermore, when a low-height (so-called short-height) cap is used, the number of turns of the screw is reduced, shortening the travel distance, making it easier for tiny insects to invade. Furthermore, if a seal point or the like is provided to fill the entry point (threaded portion) to prevent such insect intrusion, there is a risk of an increase in opening torque and a deterioration in screwability.

[0005] Special Publication No. 7-86020

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a capped container that is characterized in that it prevents the entry of microscopic insects when the lid is closed.

[0007] According to the present invention, there is provided a capped container comprising a container having a cylindrical neck and bottom, with a male thread formed on the outer peripheral surface of the neck, and a cap attached to the neck, the cap including a top wall and a cylindrical skirt wall hanging down from the periphery of the top wall, with a female thread formed on the inner peripheral surface of the skirt wall to be threaded onto the male thread, wherein the male thread comprises one or more male mating ridges, one male mating ridge and an adjacent male mating ridge have an overlapping portion where the two ridges exist in the axial direction, and a protrusion is formed in part of a recess between the one male mating ridge and the adjacent male mating ridge in the overlapping portion, the female thread comprises one or more female mating ridges, and the female mating ridge has a thick thread region where the thread width is thickened, A capped container characterized in that, in a closed state, the upper surface of the thick screw region abuts against the lower surface of the male thread engagement convex rib located above the protrusion.

[0008] The capped container of the present invention preferably employs the following features. (1) The thick thread region is formed at least at the terminal end of the effective thread portion of the female thread ridge. (2) The overlap portion is formed at the starting end of one male thread ridge and the terminal end of the male thread ridge adjacent to that one male thread ridge. (3) The distance from the radial tip of the thick thread region to the protrusion is 0.05 to 0.3 mm. (4) The distance from the lower surface of the thick thread region to the upper surface of the male thread ridge located below the protrusion is 0.05 to 0.3 mm. (5) The male thread consists of three male thread ridges, and the female thread consists of three female thread ridges. (6) The cap is a composite cap consisting of a synthetic resin outer lid having an opening on its top surface and a metal panel portion that closes the opening.

[0009] In the capped container of the present invention, a thick thread region with a large thread width is formed on the female thread formed on the cap, a protrusion is formed between the male threads formed on the container neck, and the upper surface of the thick thread region abuts against the lower surface of the male thread ridge located above the protrusion, thereby significantly reducing the gap between the male thread formed on the container and the female thread formed on the cap, thereby effectively preventing insect intrusion through the thread. Even when a low-height (so-called short-height) cap is used, insect intrusion through the thread can be effectively prevented for the same reasons as above. Furthermore, when the thick thread region is formed at least at the end of the effective thread portion of the female thread ridge, there is no effect on the initial capping after filling the contents, allowing for capping equivalent to conventional products and allowing consumers to open the cap smoothly.

[0010] (a) A partially enlarged cross-sectional view of the upper part and (b) a schematic cross-sectional view of the entire cap of an example of a capped container of the present invention in a closed state. A partially enlarged side view showing an enlarged neck portion of the container used in the capped container shown in Figure 1. (a) A side view and (b) a bottom view of the cap used in the capped container shown in Figure 1. A side cross-sectional view of the cap of Figure 3. A diagram showing the positional relationship between the female thread formed on the inner surface of the cap and the male thread formed on the container for each seaming angle in the case of a triple-thread screw. Schematic cross-sectional views of a capped container in a closed state using the triple-thread cap shown in Figure 5 for each seaming angle.

[0011] The capped container of the present invention will be described with reference to the specific example shown in the accompanying drawings.

[0012] <Capped container 1> The capped container 1 of the present invention generally comprises a container 2 having a cylindrical neck portion 11 and a bottom portion 12, and a cap 3 attached to the neck portion 11, as shown in Figure 1.

[0013] <Container 2> As shown in Fig. 2, the container 2 has a cylindrical neck portion 11 and a bottom portion 12, and a male thread 13 is formed on the outer peripheral surface of the neck portion 11. This male thread 13 can be threadably mated with a female thread 23 formed on the cap 3, which will be described later. The male thread 13 can be made up of one or more male mating ridges 14, but from the standpoint of ease of capping and quick opening, it is preferable that the male thread 13 be a triple thread made up of three male mating ridges 14, as shown in Fig. 2.

[0014] As is clear from Figure 2, one male thread ridge 14 and an adjacent male thread ridge 14 have an overlap portion 15 where they exist in the axial direction. A protrusion 18 is formed in a portion of the recess between the adjacent male thread ridge 14 in the overlap portion 15. In the capped container of the present invention, it is important that, in the closed state, the upper surface of the thick thread region 24a (described below) abuts against the lower surface of the male thread ridge 14 located above the protrusion 18. This abutment significantly reduces the gap between the male thread ridge 13 formed on the container 2 and the female thread ridge 23 formed on the cap 3, thereby preventing the entry of microscopic insects. The radial protrusion amount of the protrusion 18 can be appropriately set according to the distance A (described below).

[0015] The male thread ridge 14 is composed of an effective thread portion and an incomplete thread portion. The effective thread portion is the portion of the male thread ridge 14 where the upper surface of the female thread ridge 24 (described later) abuts against the lower surface of the male thread ridge 14. On the other hand, the incomplete thread portion is provided on both ends of the effective thread portion, and the thread width decreases toward the tip. This narrowing of the thread width makes it easier to thread the female thread ridge 23 when starting to wind or unscrew the package.

[0016] The circumferential length of the protrusion 18 may be formed in at least a part of the recess between one male thread engagement ridge 14 and an adjacent male thread engagement ridge 14 in the overlap portion 15. Furthermore, as shown in Figures 2 and 5, the protrusion 18 may be formed across the effective thread portion and the incomplete thread portion of one male thread engagement ridge 14 and the adjacent male thread engagement ridge 14.

[0017] The overlap portion 15 is preferably formed at the start portion 16 of one male thread ridge 14 and the end portion 17 of the male thread ridge 14 adjacent to that one male thread ridge 14. If the overlap portion 15 is long, it will be too long to prevent insect intrusion, which is disadvantageous in terms of cost. The start portion 16 of the male thread ridge 14 in the container 2 is the portion including the incomplete thread portion on the neck portion 11 side of the male thread ridge 14, and the end portion 17 in the container 2 is the portion including the incomplete thread portion on the bottom portion 12 side of the male thread ridge 14. In addition, in the case of a single-thread screw in which only one male thread ridge 14 is formed, it is preferable that the overlap portion 15 be formed by the start portion 16 of one male thread ridge 14 and the end portion 17 of that one male thread ridge 14.

[0018] The container 2 used in the present invention is not limited to this, but examples thereof include glass bottles and known bottles made of olefin resins, polyester resins, etc.

[0019] <Cap 3> As shown in Figures 3 and 4, the cap 3 includes a top wall 21 and a cylindrical skirt wall 22 that hangs down from the periphery of the top wall 21. An internal thread 23 is formed on the inner peripheral surface of the skirt wall 22. This internal thread 23 can be threadably mated with the external thread 13 formed on the container. The internal thread 23 can be composed of one or more internal thread ridges 24. However, from the viewpoint of ease of capping and quick opening, it is preferable that the internal thread 23 be a triple thread composed of three internal thread ridges 24, as shown in Figure 4. Furthermore, the number of external thread ridges 14 of the external thread 13 formed on the container is usually the same as the number of internal thread ridges 24 of the internal thread 23 formed on the cap 3.

[0020] The female thread ridge 24 is composed of an effective thread portion 41 and an incomplete thread portion 42. The effective thread portion 41 is the portion where the upper surface of the female thread ridge 24 and the lower surface of the male thread ridge 14 abut against each other. On the other hand, the incomplete thread portion 42 is provided on both ends of the effective thread portion 41, and is a portion where the thread width decreases toward the tip. This narrowing of the thread width makes it easier to thread the male thread ridge 13 when starting to wind or unscrew the package.

[0021] The effective thread portion of the female thread ridge 24 has a thick thread region 24a where the thread width is larger and a normal thread region 24b. In the present invention, it is important that, in the closed state, the upper surface of the thick thread region 24a abuts against the lower surface of the male thread ridge 14 located above the protrusion 18, and since the gap between the female thread ridge 23 formed on the cap and the male thread ridge 13 formed on the container 2 becomes very small, it is possible to prevent the entry of microscopic insects.

[0022] The thick thread region 24a may be formed at any position on the female thread ridge 24 as long as the upper surface of the thick thread region 24a abuts against the lower surface of the male thread ridge 14 located above the protrusion 18 and the gap between the female thread ridge 23 formed on the cap 3 and the male thread ridge 13 formed on the container 2 can be made very small, but as shown in the figure, from the viewpoint of capping and unscrewing properties, it is preferable that the thick thread region 24a be formed at least at the terminal end portion of the effective thread portion of the female thread ridge 24. That is, referring to Figure 5, the thick thread region 24a is formed at the terminal end portion of the effective thread portion so as to straddle the boundary between the effective thread portion 41 and the incomplete thread portion 42 of the female thread ridge 24, thereby eliminating any effect on the initial capping after filling the contents, thereby enabling capping equivalent to conventional products and allowing consumers to open the cap smoothly. The terminal end of the effective thread portion of the female thread ridge 24 in the cap 3 is formed in the direction of the top wall 21 of the female thread ridge 24 .

[0023] Furthermore, as described above, the thick thread region 24a has a larger thread width than the normal thread region 24b, but it is preferable that the thread width be larger on the lower surface side of the female mating ridge 24. If the thread width on the upper surface side of the female mating ridge 24 becomes too large, the frictional force with the lower surface of the male mating ridge 14 increases, which may prevent smooth mating with the male mating ridge 14 and may result in insufficient capping.

[0024] The normal thread region (region where the thread width is not increased) is the portion excluding the thick thread region 24a of the female thread ridge 24. The thread width of the thick thread region 24a of the female thread ridge 24 can be set appropriately according to the interval B described below, but may be set to 105 to 150% of the thread width of the normal thread region.

[0025] In addition, the circumferential length of the thick thread region 24a of the female threaded ridge 24 can be set appropriately depending on the setting of the allowable winding angle described below, but it may also be set to 10 to 50% of the circumferential length of the female threaded ridge 24.

[0026] In order to improve sealing performance, it is preferable that a cushioning seal material 25 is formed around the inner surface of the top wall 21 at the contact area between the inner surface of the top wall 21 and the neck portion 11 of the container 2. It is also preferable that a knurling is formed on the skirt wall 22 to prevent fingers from slipping.

[0027] The cap 3 is preferably a composite cap made up of a synthetic resin outer lid 3 a having an opening 26 on the top surface, and a metal panel portion 3 b that closes the opening 26 .

[0028] In the case of a composite cap, the synthetic resin outer lid 3a preferably has a retaining ridge formed on the inner peripheral surface of the main portion of the skirt wall in addition to the female thread 23, and has an outward curled portion 28 on the outer periphery of the metal panel portion 3b. The inner diameter of this retaining ridge is larger than the maximum outer diameter of the portion of the metal panel portion 3b other than the outward curled portion 28, but smaller than the outer diameter of the outward curled portion 28, so that the metal panel portion 3b can be held within the outer lid 3a by cooperation of the outward curled portion 28 and the retaining ridge.

[0029] Even if rust develops on the sharp cut edges generated during press-forming of the metal panel portion 3b, the sharp cut edges are rolled up inside the outward curled portion 28, making the rust invisible to consumers. The smooth outer periphery of the outward curled portion 28 of the metal panel portion 3b acts on the retaining ridges of the outer lid 3a to hold the metal panel portion 3b in the required position within the outer lid, so that resistance to relative rotation between the metal panel portion 3b and the outer lid at the beginning of the opening operation is relatively small, and only the outer lid rotates at the beginning of the opening operation, so that the rotational torque required during the opening operation is sufficiently small.

[0030] After the cap 3 has been removed from the mouth and neck 11 of the container 2, when the metal panel 3b is pushed downward through the opening 26 formed in the center of the top wall 21 of the outer lid 3a, the outward curled portion 28 of the metal panel 3b acts on the retaining ridges and female threads 23 of the outer lid 3a, thereby elastically deforming the skirt wall of the outer lid 3a. Therefore, just as when the metal panel 3b is inserted into the outer lid 3a, the metal panel 3b can be removed from the outer lid 3a with sufficient ease, and the two can be separated.

[0031] The outward curled portion 28 formed on the metal panel portion 3b can increase the rigidity of the metal panel portion 3b, and therefore, the occurrence of warping in the metal panel portion 3b is sufficiently and reliably prevented, and the occurrence of poor sealing is reliably avoided.

[0032] To prevent unauthorized use, it is preferable that a tamper-evident band (TE band) 31 is provided at the lower end of the skirt wall of the cap 3 via a breakable weakened portion 32. It is preferable that a locking protrusion 34 is formed on the inner peripheral surface of the TE band 31 so as to be able to lock onto an annular locking jaw 33 formed on the outer peripheral surface of the neck portion 11.

[0033] The synthetic resin outer lid 3a may be made of any material, but is preferably made of a resin that has been used in the past for molding plastic caps, such as an olefin-based resin such as polyethylene or polypropylene, and that can be molded by a conventionally known method such as injection molding or compression molding. The metal panel portion 3b that closes the opening may be made of any known metal, but from the viewpoint of ease of handling, it is preferably made of a metal sheet such as a thin tin plate or a thin chromated steel plate.

[0034] The capped container 1 of the present invention is sealed by a screw structure, by a method such as seaming or stoppering, and is usually manufactured by seaming the cap 3 onto the mouth and neck portion 11 of the container 2.

[0035] The positional relationship between the container 2 and the cap 3 in the closed state after seaming of the capped container 1 of the present invention is generally determined by the seaming angle, which is a value set based on various conditions such as the structure of the thread (single thread, multiple thread, etc.), the structure of the seal portion (inner ring seal, packing seal, etc.), and the required degree of sealing.

[0036] After filling the contents, the cap is sealed by setting the seaming angle to a predetermined value and capping with a constant seaming torque using a machine. However, even when the seaming torque is set to a constant value, the seaming angle may deviate (increase or decrease) from the set value (center value). This is due to dimensional errors during the manufacture of the container 2 and cap 3, the effects of expansion and contraction of materials due to the temperature environment during filling, and frictional forces, etc., which affect the ease of capping. Therefore, the seaming angle allowable during capping is set to a range including a lower limit, center, and upper limit. Even if there is a slight deviation from the center value, it is necessary to make the gap between the male thread 13 formed on the container 2 and the female thread 23 formed on the cap 3 very small to prevent insect intrusion.

[0037] Figure 5 shows the positional relationship between the female thread ridge 24 formed on the inner surface of the cap 3 and the male thread ridge 14 formed on the container 2 when the triple-thread thread is used and the threading angles are (a) 200°, (b) 215°, and (c) 230° in the capped container 1 of the present invention. The solid line indicates the female thread ridge 24 formed on the cap 3, and the dashed line indicates the male thread ridge 14 formed on the container 2. In the case shown in Figure 5, the right end of the figure (the start of the threads on the cap) is set to 0°, with a lower limit of 200°, a middle limit of 215°, and an upper limit of 230°. In this figure, the thread width of the thick thread region 24a of the female thread ridge is 1.6 mm, and the thread width of the normal thread region 24b is 1.4 mm, with the thread width of the thick thread region 24a being 114% of the thread width of the normal thread region 24b.

[0038] Figure 6 shows cross-sectional views of the capped container 1 at (a) a 190° A-A cross section at a seaming angle of 200°, (b) a 205° B-B cross section at 215°, and (c) a 220° C-C cross section at 230°, with the right end of Figure 5 being 0°. As shown in Figure 6, it can be seen that the gap between the male thread 13 formed on the container 2 and the female thread 23 formed on the cap 3 is sufficiently small regardless of the seaming angle. Therefore, with the capped container 1 shown in the figure, when capping is performed with 215° as the set value (center value) of the seaming angle, even if the seaming angle deviates from the center value, as long as the seaming angle is within the allowable range of 200° to 230°, the gap between the male thread 13 formed on the container 2 and the female thread 23 formed on the cap 3 can be sufficiently small, making it possible to effectively prevent insect intrusion.

[0039] The gap between the male thread 13 formed on the container 2 and the female thread 23 formed on the cap 3 is defined by two distances: a distance 51 (distance A) from the radial tip of the thick thread region 24a to the protrusion, and a distance 52 (distance B) from the lower surface of the thick thread region 24a to the upper surface of the male thread engagement ridge 14 located below the protrusion 18. The distance 51 (distance A) from the radial tip of the thick thread region 24a to the protrusion 18 is preferably 0.05 to 0.5 mm, and particularly preferably 0.05 to 0.3 mm. If distance A is less than 0.05 mm, threading may not be performed smoothly, and sufficient capping may not be achieved compared to when the distance is within the above range. If distance A is greater than 0.5 mm, depending on the size of the insect, it may be large enough to allow insects to enter, and insect intrusion may not be effectively prevented. The distance 52 (distance B) from the underside of the thick thread region 24a to the upper surface of the male thread engagement ridge 14 located below the protrusion 18 is preferably 0.05 to 0.5 mm, and particularly preferably 0.05 to 0.3 mm. If distance B is smaller than 0.05 mm, threading may not be performed smoothly, and sufficient capping may not be achieved compared to when the distance is within the above range. If distance B is larger than 0.5 mm, depending on the size of the insect, it may be large enough to allow entry, and insect intrusion may not be effectively prevented.

[0040] The capped container 1 of the present invention is not limited to the specific example shown in the drawings, and various modifications are possible, as long as the threads formed on the container 2 and cap 3 satisfy the above-mentioned requirements. For example, in the specific example shown in the drawings, the cap is a composite cap consisting of a synthetic resin outer lid 3a and a metal panel portion 3b, but this is not limited thereto and the cap may be made of metal or synthetic resin and have a top wall 21 and a skirt wall 22 integrally molded. Furthermore, in the specific example shown in the drawings, the container 2 and cap 3 each have three threads, but this is not limited thereto and the number of threads can be determined to be one, two, or the like, to adjust the turning angle for opening depending on the height of the cap.

[0041] 1: container with cap, 2: container, 3: cap, 3a: synthetic resin outer lid, 3b: metal panel portion, 11: neck portion, 12: bottom portion, 13: male thread, 14: male thread engagement ridge, 15: overlap portion, 16: starting end portion, 17: ending end portion, 18: protrusion, 21: top wall, 22: cylindrical skirt wall, 23: female thread, 24: female thread engagement ridge, 24a: thick thread region, 24b: normal thread region, 25: sealing material, 26: opening, 28: outward curl portion, 31: tamper evident band (TE band), 32: weakened portion, 33: annular locking jaw portion, 34: locking protrusion, 41: effective thread portion of female thread engagement ridge, 42: incomplete thread portion of female thread engagement ridge, 51: spacing A, 52: spacing B

Claims

1. A container with a cap, comprising a container having a cylindrical neck and bottom, with a male thread formed on the outer peripheral surface of the neck, and a cap attached to the neck, the cap including a top wall and a cylindrical skirt wall hanging down from the periphery of the top wall, the inner peripheral surface of the skirt wall having a female thread formed to be screwed onto the male thread, the male thread is made of one or more male mating ridges, one male mating ridge and an adjacent male mating ridge have an overlapping portion where the two exist in the axial direction, a protrusion is formed in part of a recess between the one male mating ridge and the adjacent male mating ridge in the overlapping portion, the female thread is made of one or more female mating ridges, the female thread has a thick thread region where the thread width is thickened, A container with a cap, characterized in that, in a closed state, the upper surface of the thick screw region abuts against the lower surface of the male thread engagement convex rib located above the protrusion.

2. A container with a cap according to claim 1, wherein said thick thread region is formed at least at the terminal end portion of the effective thread portion of said female thread engagement convex streak.

3. A container with a cap according to claim 1 or 2, wherein the overlapping portion is formed at the start end portion of one male thread engaging ridge and the end portion of the male thread engaging ridge adjacent to said one male thread engaging ridge.

4. A capped container according to claim 1 or 2, wherein the distance from the radial tip of said thick screw region to said protrusion is 0.05 to 0.3 mm.

5. A capped container according to claim 1 or 2, wherein the distance from the lower surface of said thick screw region to the upper surface of the male thread engagement convex rib located below said protrusion is 0.05 to 0.3 mm.

6. A container with a cap according to claim 1 or 2, wherein said male thread comprises three male mating ridges, and said female thread comprises three female mating ridges.

7. A container with a cap according to claim 1 or 2, wherein the cap is a composite cap consisting of an outer lid made of synthetic resin having an opening on the top surface, and a metal panel portion for closing the opening.

Images