Patent Application
20230373688
The present invention relates generally to a cap for sealing a can container containing a beverage and a method for manufacturing the cap.
Conventionally, a cap for sealing a mouth portion of a can container has a configuration in which a sealing member made of a resin material that comes into close contact with the mouth portion is provided on an inner surface of a cap body. As such a cap, Jpn. Pat. Appln. KOKAI Publication No. 2004-217295 and Jpn. Pat. Appln. KOKAI Publication No. 2017-178421 disclose a technique in which a cap body and a sealing member are not mutually bonded in order to reduce cap opening torque at the time of opening the cap.
For the cap described above, the sealing member is engaged with a vent slit projecting inward of a skirt portion to prevent the sealing member from falling off. However, in a case where the internal pressure of the container becomes negative, the sealing member tends to adhere to the container mouth portion side, and there is a concern that the sealing member may fall off the cap body at the time of opening the cap.
On the other hand, in a case where the vent slit is formed deeply inward in a radial direction in order to sufficiently engage with the sealing member, there is a concern that a crack may occur at an end portion of the vent slit. It is also conceivable to provide the skirt portion with a recessed portion which protrudes inward of the slitless skirt portion. However, even in a case where the sealing member is engaged with the recessed portion provided in the skirt portion, there are concerns the skirt portion may be damaged if the recessed portion is formed too deeply.
It is therefore an object of the present invention to provide a cap and a method for manufacturing the cap which can reliably prevent a sealing member from falling off without damaging a skirt portion.
According to one aspect of the present invention, a cap includes: a cap body including a top plate portion and a cylindrical skirt portion provided on a peripheral edge portion of the top plate portion; a sealing member provided in the cap body and separately from the cap body so as to face the top plate portion; a plurality of locking portions arranged in a circumferential direction in the skirt portion, the locking portions protruding inward in a radial direction of the skirt portion and supporting the sealing member; a plurality of small diameter portions arranged between the top plate portion and the locking portions of the skirt portion, the small diameter portions being respectively provided on a top plate portion side of the locking portions in the axial direction; and a plurality of large diameter portions provided adjacent to the small diameter portions in the circumferential direction and having an inscribed circle diameter larger than an inscribed circle diameter of the plurality of small diameter portions.
According to one aspect of the present invention, a method for producing a cap includes: arranging a molded product having a top plate portion and a skirt portion integrally formed with the top plate portion via an annular and curved corner portion in a first tool having a plurality of first protrusions on an outer peripheral surface thereof, a plurality of large-diameter-portion forming portions adjacent to the first protrusions in an axial direction, and small-diameter-portion forming portions adjacent to the large-diameter-portion forming portions in a circumferential direction; and forming a plurality of recessed portions, a plurality of small diameter portions, and a plurality of large diameter portions in the skirt portion by relatively rotating the first tool and a second tool having second protrusions arranged between the adjacent first protrusions of the first tool and causing the second protrusions to enter between the adjacent first protrusions.
Hereinafter, a cap 1 according to an embodiment of the present invention, a method for manufacturing the cap 1, and a manufacturing apparatus 200 for the cap 1 will be described with reference to
As shown in
As shown in
The jaw portion 111 is configured to protrude annularly. The curl portion 113 is formed to have a smaller diameter than the male screw portion 112. The curl portion 113 is configured to be smaller than the inner diameter of the cap 1. The curl portion 113 is formed by folding the end portion of the mouth portion 110 once or more. The curl portion 113 forms an opening through which the beverage contained in the can container 100 is discharged.
As shown in
The cap body 11 is made of a material obtained by forming a resin coating layer on a metal material such as an aluminum alloy. The cap body 11 is formed into a cup shape by drawing, knurling, roll-on molding, press molding or the like of the material in the form of a thin flat plate.
As shown in
The top plate portion 21 is formed in a disk shape. As shown in
One end of the skirt portion 22 is continuous with the top plate portion 21 via the corner portion 23, and the other end is open. As shown in
A cup-shaped molded product 11A composed of the top plate portion 21, the cylindrical skirt portion 22 where the plurality of locking portions 31, the plurality of vent slit portions 32, the female screw portion 33, and the tamper evidence band portion 34 are not formed, and the corner portion 23 is subjected to processing such as knurling molding or roll-on molding to form the plurality of locking portions 31, the plurality of vent slit portions 32, the female screw portion 33, and the tamper evidence band portion 34 in the skirt part 22. The female screw portion 33 is formed in a state in which the cap 1 is attached to the can container 100.
The plurality of locking portions 31 restrict movement of the sealing member 12 and hold the sealing member 12 by the skirt portion 22 being recessed inward in the radial direction. The locking portion 31 is a recessed portion in which a slit penetrating the skirt portion 22 is not formed. As shown in
As shown in
For example, in the present embodiment, thirteen locking portions 31 are provided and four vent slit portions 32 are formed along the circumferential direction of the skirt portion 22. The plurality of vent slit portions 32 are set at equal or substantially equal intervals in the circumferential direction of the skirt portion 22, and the plurality of locking portions 31 and the plurality of vent slit portions 32 are set at equal or substantially equal intervals in the circumferential direction of the skirt portion 22. The plurality of locking portions 31 are provided on the top plate portion 21 side (upper annular portion 35 side) in the axial direction of the skirt portion 22 with respect to the plurality of vent slit portions 32.
The female screw portion 33 is configured to be screwed with the male screw portion 112 of the can container 100. The female screw portion 33 is formed together with the can container 100. That is, the female screw portion 33 is not formed in a finished product of the cap 1 before being attached to the can container 100, but is formed when the cap 1 is integrally combined with the can container 100.
The tamper evidence band portion 34 engages with the jaw portion 111 of the can container 100 in a direction in which the cap 1 moves away from the can container 100 and in an axial direction of the cap 1. In addition, the tamper evidence band portion 34 has a breaking portion 34a, which is broken and detached from the skirt portion 22 when the cap 1 is opened. That is, the tamper evidence band portion 34 is configured by forming a slit on the end portion side of the skirt portion 22 while leaving the breaking portion 34a, and is formed into the shape of the jaw portion 111 of the can container 100 when integrally combined with the can container 100, thereby engaging with the jaw portion 111, in a manner similar to the female screw portion 33.
The upper annular portion 35 is formed at a portion located between the top plate portion 21 and the plurality of locking portions 31 of the skirt portion 22. For example, the upper annular portion 35 is formed in a part of the corner portion 23. The upper annular portion 35 has a plurality of small diameter portions 35a and a plurality of large diameter portions 35b in the circumferential direction thereof. The inscribed circle diameter (inner diameter) of the plurality of small diameter portions 35a is relatively smaller than the inscribed circle diameter (inner diameter) of the plurality of large diameter portions 35b.
The small diameter portion 35a is adjacent to the locking portion 31 in the axial direction of the cap 1. The inscribed circle diameter (inner diameter) of the plurality of small diameter portions 35a is set to be smaller than the outer diameter of the sealing member 12, and the inscribed circle diameter (inner diameter) of the plurality of large diameter portions 35b is set to be larger than the outer diameter of the sealing member 12.
In the upper annular portion 35 described above, when the plurality of locking portions 31 are formed, the plurality of small diameter portions 35a are formed by recessing portions of the upper annular portion 35 adjacent to the upper portions of the respective locking portions 31 inward in the radial direction. In the upper annular portion 35, portions where the plurality of small diameter portions 35a are not formed, that is, portions between the plurality of small diameter portions 35a in the circumferential direction, respectively constitute the plurality of large diameter portions 35b.
In the present embodiment, the plurality of vent slit portions 32 are set at equal or substantially equal intervals in the circumferential direction of the skirt portion 22, and the plurality of locking portions 31 and the plurality of vent slit portions 32 are set at equal or substantially equal intervals in the circumferential direction of the skirt portion 22. Therefore, the circumferential length of the large diameter portion 35b corresponding to the portion where the two locking portions 31 are adjacent in the circumferential direction of the skirt portion 22 is shorter than the circumferential length of the large diameter portion 35b corresponding to the portion where the two locking portions 31 between which the vent slit portion 32 is disposed are adjacent in the circumferential direction of the skirt portion 22.
As shown in
As shown in
For example, as illustrated in
The sliding layer 41 is made of a resin material having a relatively higher hardness (harder) than the sealing layer 42. The sliding layer 41 is made of a resin material having neither adhesiveness nor stickiness to the resin coating layer of the cap body 11. That is, the sliding layer 41 is not bonded to the top plate portion 21 and slides on the top plate portion 21 in a state of being in contact with the top plate portion 21.
Examples of the resin material used for the sliding layer 41 include olefin-based resins such as polypropylene resin and polyethylene resin, polyester-based resins such as polyethylene terephthalate, styrene-based resins, and acrylic-based resins. In the present embodiment, the sliding layer 41 is made of, for example, polypropylene resin. A pigment, a lubricant, a softener, and the like can be appropriately added to the resin material used for the sliding layer 41. In the example of the present embodiment, the hardness of the sliding layer 41 is D10 to D70 in terms of the durometer D hardness according to JIS K7215.
As shown in
As illustrated in
The first curved surface portion 41b is configured such that the portion from the outer peripheral side of the portion of the mouth portion 110 facing the curl portion 113 to the outer peripheral edge gradually decreases in thickness toward the outer peripheral edge. The protruding portion 41c is configured in an annular protruding shape that is inclined with respect to the axial direction of the sliding layer 41 and the surface direction of the top plate portion 21, and is curved or inclined toward the open end portion side of the skirt portion 22. The protruding portion 41c gradually decreases in thickness from the first curved surface portion 41b toward the distal end.
The sealing layer 42 is made of a resin material having a relatively lower hardness (softer) than the sliding layer 41. Examples of the resin material used for the sealing layer 42 include an olefin-based resin, a polyester-based resin, a styrene-based resin, an acrylic-based resin, and the like, and more preferably include a blended material of a styrene-based elastomer and a polypropylene resin, a blended material of low-density polyethylene and a styrene-based elastomer, a polyester-based elastomer, and the like. The resin material used for the sealing layer 42 has adhesion to the resin material used for the sliding layer 41. In the present embodiment, the sealing layer 42 is made of, for example, a blended material of a styrene-based elastomer and a polypropylene resin. A pigment, a lubricant, a softener, and the like can be appropriately added to the resin material used for the sealing layer 42.
As shown in
As illustrated in
The second curved surface portion 42b has, for example, a main surface flush with the main surface of the second flat plate portion 42a facing the curl portion 113. The second curved surface portion 42b is configured such that the portion from the outer peripheral side of the portion of the mouth portion 110 facing the curl portion 113 to the outer peripheral edge gradually decreases in thickness toward the outer peripheral edge. The second curved surface portion 42b is laminated on the first curved surface portion 41b and the protruding portion 41c. The second curved surface portion 42b constitutes the curved surface portion 12b of the sealing member 12 together with the first curved surface portion 41b and the protruding portion 41c.
The thick portion 42c is an annular protrusion protruding from the main surface of the second flat plate portion 42a on the side opposite to the sliding layer 41. The thick portion 42c constitutes a sealing portion which abuts the mouth portion 110 of the can container 100. The sliding layer 41 may have a configuration in which a thin portion that is a recess is provided at a portion facing the thick portion 42c, with the thick portion 42c protruding annularly from both main surfaces of the second flat plate portion 42a so as to secure a collapse margin of the thick portion 42c.
The sliding layer 41 and the sealing layer 42 are configured such that the first curved surface portion 41b, the protruding portion 41c, and the second curved surface portion 42b are each thinner than the first flat plate portion 41a and the second flat plate portion 42a.
Next, a method for manufacturing the cap 1 configured as described above will be described with reference to
First, a sheet-like metallic material is drawn by a shell press apparatus to form a molded product 11A (step ST1). Next, the sliding layer 41 is molded on the top plate portion 21 of the molded product 11A by a sliding layer forming apparatus (step ST2).
Next, the sealing layer 42 is molded on the sliding layer 41 in the molded product 11A by a sealing layer forming apparatus (step ST3). Thus, the sealing member 12 is molded in the molded product 11A.
Next, the sealing member 12 in the molded product 11A is removed by a sealing member conveying apparatus (step ST4). Next, the plurality of locking portions 31, the plurality of vent slit portions 32, the tamper evidence band portion 34, and the upper annular portion 35 are formed by a molded product processing apparatus in the molded product 11A from which the sealing member 12 has been removed (step ST5).
Next, the sealing member 12 is inserted by the sealing member conveying apparatus into the molded product 11A in which the plurality of locking portions 31, the plurality of vent slit portions 32, the tamper evidence band portion 34, and the upper annular portion 35 are molded (step ST6). Through these steps, the cap 1 is manufactured (step ST7).
For example, the manufactured cap 1 is collected in a collection unit. When a certain number of caps 1 are collected, they are conveyed to a next step, i.e., an inspection and packaging step, where they are subjected to quality inspection and packaging.
Next, a method for capping the mouth portion 110 of the can container 100 with the manufactured cap 1 will be described. For example, the cap 1 is put on the mouth portion 110 of the can container 100 so that the curl portion 113, which is the distal end portion of the mouth portion 110 of the can container 100, is in contact with the sealing layer 42 of the sealing member 12. In this state, a load is applied to the top plate portion 21 of the cap body 11, and the skirt portion 22 is roll-on molded while the corner portion 23 is drawn downward (toward the can container 100). As a result, as shown in
Next, an example of a configuration of the manufacturing apparatus 200 which is used in the molded product processing apparatus and molds the plurality of locking portions 31, the plurality of vent slit portions 32, and the upper annular portion 35 of the cap 1 in the aforementioned step ST5 will be described with reference to
In
As shown in
As illustrated in
The first base portion 221 is disposed in the skirt portion 22 of the cap body 11. The first base portion 221 has a cylindrical shape having an outer diameter smaller than the inner diameter of the skirt portion 22. The first base portion 221 has, for example, a hole 221a into which the rotary shaft 227 is inserted. The hole 221a has, for example, a key groove.
The first protrusion 222 has, for example, a semi-cylindrical shape whose axial direction is along the axial direction of the first base portion 221 or a triangular prism shape in which both side portions are curved. The plurality of first protrusions 222 are arranged in the circumferential direction with a predetermined distance between the adjacent first protrusions 222. Here, the predetermined distance is set to a width larger than a circumferential width of a second protrusion 232 of the second tool 212, which will be described later.
The cutter portion 223 is a protrusion that shears, breaks, or cuts a portion of the skirt portion 22 where the vent slit 32b is formed, together with the second protrusion 232 of the second tool 212. The cutter portion 223 is arranged between adjacent first protrusions 222 among the plurality of first protrusions 222 on one end side of each of the adjacent first protrusions 222.
The small-diameter-portion forming portion 224 is a recess provided adjacent to the end portion side of the first protrusion 222 of the first base portion 221 in the axial direction. The large-diameter-portion forming portion 225 is a protrusion formed adjacent to the small-diameter-portion forming portion 224 in the circumferential direction. The large-diameter-portion forming portion 225 is provided in a range adjacent to the cutter portion 223 in the axial direction. The plurality of small-diameter-portion forming portions 224 and the plurality of large-diameter-portion forming portions 225 are recesses and protrusions provided in the circumferential direction at the end portion of the first base portion 221.
The first tamper-evidence-band-portion forming portion 226 forms the skirt portion 22 in the shape of the tamper evidence band portion 34 and forms a plurality of breaking portions 34a by intermittently forming slits.
The rotary shaft 227 is fixed to the hole 221a of the first base portion 221. The rotary shaft 227 is connected to the driving device 213.
The second tool 212 is a tool that is disposed on the outer peripheral surface side of the skirt portion 22 and forms the plurality of locking portions 31, the plurality of vent slit portions 32, the tamper evidence band portion 34, the plurality of small diameter portions 35a, and the plurality of large diameter portions 35b in the skirt portion 22 together with the first tool 211. As illustrated in
The second base portion 231 has, for example, an arc plate shape. For example, the outer diameter of the second base portion 231 is set to be larger than the outer diameter of the first base portion 221 and the outer diameter of the skirt portion 22. The second base portion 231 may have a disk shape, a quarter circle shape, or a semicircle shape as long as it has an outer peripheral surface with a radius of curvature capable of suitably forming the plurality of locking portions 31, the plurality of vent slit portions 32, the plurality of small diameter portions 35a, and the plurality of large diameter portions 35b together with the first tool 211. Further, the second base portion 231 may be rotatable, or may be configured not to be rotated if the first base portion 221 is configured to be rotated.
For example, the tip of the second protrusion 232 is formed in a curved surface shape, and one end side in the axial direction (the top plate portion 21 side of the skirt portion 22) is formed in a flat surface shape. In addition, the second protrusion 232 is formed in a shape in which the width gradually decreases toward the tip in the axial direction and the direction orthogonal to the axial direction.
As illustrated in
The second tamper-evidence-band-portion forming portion 233 forms the skirt portion 22 in the shape of the tamper evidence band portion 34 together with the first tamper-evidence-band-portion forming portion 226, and forms the plurality of breaking portions 34a by intermittently forming slits.
The end face of the tip of the second protrusion 232 enters between the adjacent first protrusions 222, thereby pressing the skirt portion 22 to form a recessed portion. As a specific example of step ST5 of the manufacturing method described above, the first tool 211 and the second tool 212 are relatively moved in a state in which the first base portion 221 of the first tool 211 is inserted into the molded product 11A. Then, as illustrated in
For example, in a case where the cutter portion 223 is adjacent to the first protrusion 222 in the axial direction, as shown in
In a case where the cutter portion 223 is not adjacent to the end portion of the first protrusion 222 in the axial direction, as shown in
Further, at this time, as shown in
The driving device 213 is a driving source that relatively rotates the first tool 211 and the second tool 212. The driving device 213 rotates, for example, the rotary shaft 227. The driving device 213 is, for example, a motor or a transmission mechanism that transmits rotation of the motor to the rotary shaft 227. The driving device 213 rotates the first tool 211 in one direction.
The driving device 213 need only relatively rotate the first tool 211 and the second tool 212, and may be configured to rotate the second base portion 231 of the second tool 212 instead of rotating the first base portion 221 via the rotary shaft 227 of the first tool 211, or may rotate both the first base portion 221 and the second base portion 231. For example, the driving device 213 may be configured to be movable between an initial position at which the cap body 11 is disposed on the first tool 211 and a molding position at which the first tool 211 and the second tool 212 are in a predetermined positional relationship to mold the cap body 11.
According to the cap 1 configured as described above and the method for manufacturing the cap 1, the skirt portion 22 (the upper annular portion 35) between the top plate portion 21 and the plurality of locking portions 31 has the small diameter portions 35a in which the inner diameter above the locking portions 31 is smaller than the inner diameter above the portion where the locking portions 31 are not formed. Thus, the metallic material that existed before formation of the small diameter portions 35a at the position where the small diameter portions 35a are set to be formed is drawn radially inward when the locking portions 31 are formed. Therefore, without damaging the skirt portion 22, the locking portions 31 can be formed deeply inward in the radial direction, and the inscribed circle diameter of the plurality of locking portions 31 can be reduced. That is, the inscribed circle diameter of the plurality of locking portions 31 can be smaller than the outer diameter of the sealing member 12. Since the sealing member 12 can be supported by the plurality of locking portions 31, it is possible to reliably prevent the sealing member 12 from falling off from the cap body 11.
Furthermore, by setting the inner diameter of the inscribed circle of the plurality of small diameter portions 35a to be smaller than the outer diameter of the sealing member 12, the inner peripheral surfaces of the small diameter portions 35a come into contact with the outer peripheral edge of the sealing member 12, so that the inner peripheral surfaces of the small diameter portions 35a retain the sealing member 12. Therefore, the cap body 11 can fix the outer peripheral portion of the sealing member 12 via the small diameter portions 35a in addition to support by the plurality of locking portions 31, and can more reliably prevent the sealing member 12 from falling off the cap body 11. In addition, the sealing member 12 disposed in the cap body 11 is positioned in the radial direction by the inner peripheral surfaces of the plurality of small diameter portions 35a. Therefore, when the cap 1 is attached to the can container 100, the thick portion 42c of the sealing member 12 reliably faces the mouth portion 110 of the can container 100, so that the cap 1 can reliably seal the can container 100.
As described above, according to the cap 1 and the method for manufacturing the cap 1 of the embodiment of the present invention, the plurality of locking portions 31 supporting the sealing member 12 can be formed without damaging the skirt portion 22, and the locking portions 31 can be formed deeply. Therefore, the cap 1 and the method for manufacturing the cap 1 can reliably prevent the sealing member 12 from falling off the cap body 11.
Note that the present invention is not limited to the embodiment described above. For example, although the numbers of the plurality of locking portions 31 and the plurality of vent slit portions 32 have been described as examples, the numbers of the locking portions 31 and the vent slit portions 32 can be set as appropriate. That is, the number of the locking portions 31 may be the same as the number of the vent slit portions 32, or greater or lesser than the number of the vent slit portions 32. In addition, the shapes of the locking portion 31 and the vent slit portion 32 can be appropriately set. In addition, the position and the opening area of the vent slit 32b of the vent slit portion 32 can be appropriately set.
That is, as long as the sealing member 12 can be supported by the plurality of locking portions 31, the numbers, shapes, and the like of the locking portions 31 and the vent slit portions 32 can be appropriately set depending on the shapes of the cap 1 and the can container 100, the contents to be contained in the can container 100, the internal pressure in the can container 100, and the like.
That is, the present invention is not limited to the above-described embodiment, and in the practical stage, various modifications may be made without departing from the spirit of the invention. Furthermore, embodiments may be appropriately combined and implemented, and in that case, the combined effects may be obtained. Furthermore, the embodiment described above includes various inventions, and various inventions can be extracted by a combination selected from structural elements disclosed herein. For example, if the object of the invention is achieved and the advantages of the invention are attained even after some of the structural elements disclosed in connection with the embodiments are deleted, the structure made up of the resultant structural elements can be extracted as an invention.
1: cap, 11: cap body, 11A: molded product, 12: sealing member, 12a: flat plate portion, 12b: curved surface portion, 21: top plate portion, 22: skirt portion, 23: corner portion, 31: locking portion, 31a: upper inclined surface, 31b: lower inclined surface, 32: vent slit portion, 32a: recessed portion, 32b: vent slit, 33: female screw portion, 34: tamper evidence band portion, 34a: breaking portion, 35: upper annular portion, 35a: small diameter portion, 35b: large diameter portion, 41: sliding layer, 41a: first flat plate portion, 41b: first curved surface portion, 41c: protruding portion, 42: sealing layer, 42a: second flat plate portion, 42b: second curved surface portion, 42c: thick portion, 100: can container, 110: mouth portion, 111: jaw portion, 112: male screw portion, 113: curl portion, 200: manufacturing apparatus, 211: first tool, 212: second tool, 213: driving device, 221: first base portion, 221a: hole, 222: first protrusion, 223: cutter portion, 224: small-diameter-portion forming portion, 225: large-diameter-portion forming portion, 226: first tamper-evidence-band-portion forming portion, 227: rotary shaft, 231: second base portion, 232: second protrusion, 232A: first teeth, 232B: second teeth, 233: second tamper-evidence-band-portion forming portion.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-016710 | Feb 2021 | JP | national |
This application is a Continuation Application of PCT Application No. PCT/JP2022/002840, filed Jan. 26, 2022 and based upon and claiming the benefit of priority from Japanese Patent Application No. 2021-016710, filed Feb. 4, 2021, the entire contents of all of which are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2022/002840 | Jan 2022 | US |
| Child | 18363988 | US |
