JP7096023B2 - Resin screw cap with opening tab and its manufacturing method - Google Patents

Description

The present invention relates to a resin cap that is wound around the mouth of a container such as a bottle or a resin bottle and seals the contents contained in the container.

Conventionally, as a cap to be attached to the mouth of the container described above, a metal cap with a tab (so-called maxi cap) having a ring-shaped grip portion on which a finger can be hung is known. Such maxi caps are provided with a tearing score from the side to the top. Then, at the time of opening, the tab is pulled up by putting a finger on the grip portion to tear a part of the maxi cap along the score, and by further pulling up the tab, the maxi cap is separated from the mouth of the container and the opening is completed.

However, with the above-mentioned maxi cap, it cannot be said that there is no possibility of cutting a finger or the like with a metal piece torn at the time of opening, and there is a problem that the usability cannot be said to be high. On the other hand, in addition to the maxi cap described above, the contents of the container can be sealed by winding the mouth of the container in which the screw portion is formed with the screw portion formed in the cap body. Resin or metal screw caps are also known.

However, since the screw cap described above also has a structure in which the cap is closed via a screw, for example, it is often screwed relatively strongly, and a high torque is required for opening the cap, or the outer wall of the cap is gripped. There is also a problem that it is difficult to open, especially for users with weak turning power such as elderly people, such as slipping when opening the cap.

On the other hand, in Patent Document 1, for example, as shown in FIGS. 20 to 27, a synthetic resin bottle lid that opens and closes by forming a spiral groove 43 on the inner surface of the side surface portion 3 of the bottle lid and rotating it. On the other hand, a bottle lid in which a pulling handle-shaped cutting groove 50 is provided on the side surface portion 3 and connected to the cutting groove 51 on the upper surface portion is disclosed. According to the bottle cap of Patent Document 1 having such a structure, it is said that a bottle lid made of synthetic resin that can be easily removed by a one-touch method and does not have a sharp portion after removal can be provided. ..

Japanese Unexamined Patent Publication No. 7-69358

However, it cannot be said that the techniques including the above-mentioned patent documents still meet the needs of the market, and at least the following problems exist.
That is, according to the bottle lid shown in Patent Document 1, since the cap is made of synthetic resin, it is possible to suppress the risk that the user accidentally injures his hand when opening the cap, and in addition, a high torque for opening the cap is suppressed. Has the advantage of improving usability because it is relatively unnecessary.

On the other hand, in the bottle lid shown in Patent Document 1, it is indispensable to form a cutting groove 51 on the upper surface portion and a cutting groove 50 on the side surface portion due to its structure, and the strength and rigidity of the cutting groove are inevitably lowered. It ends up. Therefore, for example, when the bottle lid is wound around the mouth of the container after the container is filled with the contents, the cutting groove on the upper surface is formed due to the closing torque (for example, a force that turns clockwise) or an unintended pressure. It is undeniable that it may break.

One of the objects of the present invention under such a background is that there is no risk of hand injury while improving convenience at the time of opening, and yet a part of the cap is intended at the time of winding the cap, for example. It is an object of the present invention to provide a resin cap which is prevented from breaking without breaking.

In order to solve the above problems, the resin screw cap with a tab for opening in one embodiment of the present invention is provided with (1) an inner ring on the lower surface which is in close contact with the inner surface of the cylindrical side wall of the container mouth to form a seal. An opening tab having a top plate, a tab body that is bent from a part of the peripheral edge of the top plate and descends along the axial direction, and a grip portion formed at the bottom of the tab body, and the top plate. As well as descending from the rest of the peripheral edge of the face plate , the inner peripheral surface includes a skirt wall in which a screw portion formed on the outer surface of the cylindrical side wall of the container mouth portion is formed and a screw thread is formed. A breakable weakening line is formed in at least a part of the upper end portion of the skirt wall connected to the peripheral edge of the face plate, and a part of the skirt wall is cut out so that the cut-out part is inside the cut-out part. A tab body can be attached, and the tab body has a first locking portion that engages with a first locked portion formed on the skirt wall to restrict the movement of the tab body in the axial direction. The first locking portion is formed of a side sleeve portion extending in the circumferential direction from the tab body so as to intersect the axial direction, and the first locked portion is formed. Is characterized by being composed of a pair of upper and lower convex portions protruding in the radial direction from the skirt wall so as to sandwich the lateral sleeve portion in the axial direction .

Further, in the resin screw cap with a tab for opening according to any one of the above ( 1 ), ( 2 ) the first locking portion starts from the tab body so as to intersect the axial direction. The first locked portion is composed of lateral sleeve portions extending on both sides in the circumferential direction, and the first locked portion is a pair of upper and lower convex portions arranged on both sides in the circumferential direction with respect to the tab body in the axial direction. It is preferably configured.

Further, in the resin screw cap with a tab for opening according to the above ( 1 ) or ( 2 ), ( 3 ) the tab body engages with a second locked portion formed on the skirt wall. Therefore, it is preferable that a second locking portion that regulates the expansion of the diameter of the tab body in the radial direction of the skirt wall is formed.

Further, in the resin screw cap with a tab for opening according to any one of (1) to ( 3 ) above, ( 4 ) the opening is performed from another part of the peripheral edge of the top plate so as to straddle the weakening line. It is also preferred to further provide a reinforcing strap that is connected to the tab to prevent breakage of the weakening line when unopened.

Further, in the resin screw cap with the opening tab described in ( 4 ) above, ( 5 ) the weakening line is in the circumferential direction with the center of the bending point of the opening tab on the peripheral edge of the top plate as a base point. It is preferably formed so as to extend to both sides by more than 90 degrees, and the reinforcing strap straddles the vicinity of the center of the weakening line and is connected to the peripheral edge of the top plate.

Further, in the resin screw cap with a tab for opening according to any one of (1) to ( 5 ) above, ( 6 ) the inner peripheral surface of the skirt wall is rotated below the thread . A plurality of locking protrusions are formed so as to line up in the direction, and when the locking protrusions of the skirt wall get over the circumferential protrusions formed on the tubular side wall of the container mouth portion, the threads of the skirt wall are formed. It is preferable that the meshing with the screw portion of the container mouth portion is completed.

Further, in order to solve the above-mentioned problems, the method for manufacturing a resin screw cap with a tab for opening in one embodiment of the present invention is ( 7 ) in close contact with the inner surface of the cylindrical side wall of the container mouth to form a seal. A part of the skirt wall hanging from the peripheral edge of the top plate provided with the inner ring on the lower surface is cut out, and the inner peripheral surface of the skirt wall is a screw formed on the outer surface of the cylindrical side wall of the container mouth portion. A method for manufacturing a resin screw cap with an opening tab , in which a thread to be screwed with a portion is formed and an opening tab is attached to the cutout portion, and is formed on the main surface of the top plate. By forming the opening tab extending from a part of the peripheral edge of the top plate so as to be parallel to the top plate, and by bending the opening tab in the axial direction starting from the peripheral edge of the top plate. The step of lowering the opening tab from the peripheral edge of the top plate and attaching the opening tab to a part of the notched skirt wall, and the opening tab is attached to the notched skirt wall. When attached to the portion, the first locking portion formed on the tab body of the opening tab engages with the first locked portion formed on the skirt wall, whereby the tab body is said to be said. The movement in the axial direction is restricted, and the first locking portion is composed of a side sleeve portion extending in the circumferential direction from the tab body so as to intersect the axial direction, and the first engaging portion is engaged. The stop portion is characterized by being composed of a pair of upper and lower convex portions protruding in the radial direction from the skirt wall so as to sandwich the lateral sleeve portion in the axial direction .

According to the resin screw cap with an opening tab of the present invention, the opening tab enhances convenience at the time of opening and is made of resin, so that there is no risk of injury to the hand or the like, and further, the first locking It is possible to prevent the opening tab from being unintentionally detached from the cap body by the portion.

It is an external view of the resin screw cap 100 with a tab for opening according to an embodiment. It is a top view, a sectional view and a side view of the resin screw cap 100 with a tab for opening. It is a cross-sectional view of AA in the case where the cross section is cut by AA of the upper surface of FIG. A cross-sectional view when the opening tab 40 is attached to the skirt wall 50, a partially enlarged view showing the engagement between the first locking portion 21 and the first locked portion 51, and a tubular shape of the container mouth portion 201. It is sectional drawing which shows the state which the resin screw cap 100 with a tab for opening is wound around the side wall 202. It is an external view of the resin screw cap 100 with the opening tab in the state where the opening tab 40 is opened, as seen from the bottom side. An external view of the container 200 with an excerpt of the container mouth 201, and a schematic view illustrating a meshed state when a resin screw cap 100 (partially excerpted) with a tab for opening is wound around the container mouth 201. Is. It is a flowchart for demonstrating the manufacturing method of the resin screw cap 100 with a tab for opening. It is a top view of the resin screw cap 100 with a tab for opening according to the modification 1. It is a top view of the resin screw cap 100 with a tab for opening which concerns on modification 2. FIG.

Hereinafter, embodiments for preferably carrying out the present invention will be described.
In the present embodiment, for convenience of explanation, the container 200 to which the resin screw cap 100 with a cap for opening is mounted is shown centering on the container mouth 201, but in a portion of the container 200 not shown. As the structure, a known structure can be applied. Further, although the X, Y and Z directions are appropriately set in the explanation using each figure, this orientation is for convenience of explanation and does not excessively limit the present invention.

<Resin screw cap 100 with tab for opening>
The resin screw cap 100 with a tab for opening according to the present embodiment will be described with reference to FIGS. 1 to 6 as appropriate. In addition to the configurations described below, known structures may be appropriately applied as long as the gist of the present invention is met.
The resin screw cap 100 with a tab for opening has a function of being attached to the container mouth 201 of the container 200, which will be described later, to seal the contents contained in the container 200, and has a function of sealing the contents contained in the container 200. It is configured to include at least a tab 40 and a skirt wall 50.

The material of the resin screw cap 100 with a tab for opening is not particularly limited, but for example, an olefin resin such as polyethylene resin (for example, high-density polyethylene also referred to as HDPE), polypropylene resin, or other known synthetics. Resin can be applied. Further, examples of the container 200 suitable for this embodiment include PET bottles made of synthetic resin, but the material thereof is not limited to synthetic resin, and various known materials such as glass bottles may be applied. The contents contained in the container 200 are not particularly limited, and examples thereof include dairy products, various beverage liquids such as water and tea, and seasoning liquids such as soy sauce and noodle soup.

Hereinafter, each component of the resin screw cap 100 with a cap for opening (hereinafter, also appropriately referred to as “screw cap 100”) will be described in detail.
As shown in FIGS. 1, 2 and 4, the top plate 10 includes an inner ring 11, an outer ring 12, and the like.

The inner ring 11 has a function of forming a seal in close contact with the inner surface 202a of the tubular side wall 202 of the container mouth portion 201, and is a tubular portion that hangs downward from the lower surface of the top plate 10. .. More specifically, the outer peripheral surface of the inner ring 11 hangs down while expanding its diameter toward the outer side in the circumferential direction about the Z axis so as to be slightly larger than the inner diameter of the tubular side wall 202. It can be fitted to the inner surface 202a.

The outer ring 12 is a tubular portion that hangs downward from the lower surface of the top plate 10 so as to be on the outer peripheral side of the inner ring 11 described above. Further, as is clear from the figure, the height of the outer ring 12 hanging from the top plate 10 is set to be lower than that of the inner ring 11. In such an outer ring 12, since the inner peripheral surface of the outer ring 12 is arranged along the outer surface 202b of the tubular side wall 202, the cap is displaced, for example, when a large impact is applied to the screw cap 100. It also functions as a protective wall to prevent it from happening.

Next, the structure of the opening tab 40 in the present embodiment will be described in detail.
As shown in FIG. 2, for example, the opening tab 40 includes a tab body 20 that is bent from a part 10b of the peripheral edge of the top plate 10 and descends along the axial direction (Z-axis direction). It is composed of a grip portion 30 formed in a ring shape downward from the lower portion of the tab body 20 (the side opposite to the connection portion to the top plate 10).
Of these, the tab body 20 includes a side sleeve portion 21a, a reinforcing strap 22, a locking groove portion 23a, and the like.

The side sleeve portion 21a is circumferentially oriented (θz direction) from the tab body 20 so as to intersect the axial direction (Z direction) of the screw cap 100 when attached to the notched part 50b of the skirt wall 50. Extend to. In the present embodiment, the screw cap 100 extends so as to be orthogonal to the axial direction (Z direction), but it does not necessarily have to be orthogonal to each other and may intersect. Further, the side sleeve portion 21a extends along the main surface so as to be substantially parallel to the X direction, but becomes a curved main surface so as to imitate the skirt wall 50 described later, and becomes a circumferential direction (θz direction). May be extended to.

This side sleeve portion 21a functions as the first locking portion 21 in the present embodiment, and engages with the first locked portion 51 formed on the skirt wall 50, which will be described later, in the axial direction of the tab body 20. It has a function to regulate the movement to.
The side sleeve portion 21a as the first locking portion 21 in the present embodiment is located on both sides in the circumferential direction (both clockwise and counterclockwise sides) starting from the tab body 20 so as to intersect with respect to the axial direction. However, the present invention is not limited to this form, and the side sleeve portion 21a may be formed so as to extend to at least one side with respect to the tab body 20.

The reinforcing strap 22 is connected to the opening tab 40 from the other portion 10a of the peripheral edge of the top plate 10 so as to straddle the weakening line WL described later, and has a function of suppressing breakage of the weakening line WL when it is not opened. ing. Although the width of the reinforcing strap 22 is not particularly limited, it is preferably smaller than the width of the tab body 20, for example, from the viewpoint of cost reduction and aesthetics.

The weakening line WL of the present embodiment is formed so as to extend over 90 degrees on both sides in the circumferential direction from the center of the bending point of the opening tab 40 on the peripheral edge of the top plate 10 as a base point. The strap 22 straddles the vicinity of the center of the weakening line WL and connects the peripheral edge of the top plate 10 and the opening tab 40. The weakening line WL of the present embodiment is formed long in the circumferential direction as described above, and has a structure in which portions other than both ends are relatively easy to break.

That is, the vicinity of the connection with the opening tab 40 and the end on the opposite side thereof have relatively high rigidity and have a certain degree of resistance to unintended opening pressure, but if the ease of opening is to be ensured, a weakening line is used. The WL cannot increase its strength excessively, and the vicinity of the center of the weakening line WL only secures the rigidity by the breakable bridge WLb described later, and becomes vulnerable to unintended breakage. However, in the present embodiment, since the reinforcing strap 22 straddles the fragile portion (near the center) of the weakening line WL, it is possible to secure resistance to such an unintended breakage.

The arrangement position of the reinforcing strap 22 is not limited to the above, and as long as the weakening line WL has resistance to unintended breakage, it straddles a portion other than the vicinity of the center of the weakening line WL and is used for opening the peripheral edge of the top plate 10. It may be connected to the tab 40. The term "near the center" in the present embodiment means a position where the point is closer to the center than the end.
Further, since the reinforcing strap 22 is molded by injection molding as described later, it is integrally formed with the top plate 10 and the opening tab 40, but it is not limited to such a form and is formed separately from these. It may be in the form of being retrofitted by a known fixing means such as an adhesive.

The locking groove portion 23a functions as the second locking portion 23 in the present embodiment, and engages with the second locked portion 52 (engagement hook 52a) formed on the skirt wall 50 described later to be the skirt wall. It has a function of restricting the expansion of the diameter of the tab body 20 in the unintended radial direction (outward direction around the Z axis) of the 50. That is, the engagement between the second locking portion 23 and the second locked portion 52 makes it more reliable that the tab body 20 maintains the stored state in the notched part 50b of the skirt wall 50. There is. More specifically, the locking groove portion 23a of the present embodiment is arranged at a position closer to the grip portion 30 than the side sleeve portion 21a of the tab main body 20. In other words, the locking groove portion 23a is formed on the tab body 20 so as to be located below the side sleeve portion 21a (on the side opposite to the top plate 10) when the tab body 20 is attached to the skirt wall 50. Has been done.

More specifically, the locking groove portion 23a in the present embodiment is a rectangular through hole formed in the tab body 20, and has a shape to which an engaging hook 52a described later can be inserted. However, the shape of the locking groove portion 23a is not limited to a rectangular shape, and may be various circular shapes including an ellipse. Further, if the engaging hook 52a can be engaged, it is not a through hole but a bottomed recess. It may be.

The locking groove portion 23a as the second locking portion 23 in the present embodiment is arranged on both sides in the circumferential direction (both clockwise and counterclockwise sides) starting from the center of the tab body 20 with respect to the axial direction. It is configured to be. However, not limited to this form, the locking groove portion 23a extends to at least one side with respect to the center of the tab body 20 as long as the diameter expansion of the tab body 20 in the unintended radial direction of the skirt wall 50 can be regulated. It may be formed to be present.

The grip portion 30 is a portion formed in a ring shape downward from the lower part of the tab body 20. At the time of opening, the tab body 20 is detached from the skirt wall 50 by first inserting a finger or the like into the grip portion 30 and pulling it upward, and then the weakening line WL is broken. The screw cap 100 can be detached from the container mouth 201. Become.

Subsequently, the structure of the skirt wall 50 in the present embodiment will be described in detail.
The skirt wall 50 is formed so as to descend from the remaining portion 10a (the region not connected to the opening tab 40) of the peripheral edge of the top plate 10, as shown in FIGS. 2, 4 and 5, for example. As described above, in the present embodiment, since the screw cap 100 is formed by injection molding, the skirt wall 50 is integrally formed with the top plate 10.

Further, as shown in FIG. 2, at least a part of the upper end portion 50a of the skirt wall 50 connected to the remaining portion 10a of the peripheral edge of the top plate 10 is formed with a breakable weakening line WL. As described above, in the present embodiment, as an example, a weakening line WL is formed along the peripheral edge of the top plate 10 in a region up to about 120 degrees on both sides in the circumferential direction with the center of the bending point of the opening tab 40 as a base point. ing.

The weakening line WL is preferably torn by a force within an appropriate range when the opening tab 40 is pulled up at the time of opening, and as a specific structure, for example, the peripheral edge of the top plate 10 and the upper end 50a of the skirt wall 50. It is preferably composed of at least one breakable bridge WLb that intermittently connects the bridges.
If an excessive tearing force is not required at the time of opening, for example, the weakening line WL may be formed as a continuous thinned score line in the circumferential direction.
Further, although the weakening line WL is formed on the skirt wall 50 in the present embodiment, the weakening line WL may be formed on the peripheral edge of the top plate 10.

On the other hand, as illustrated in FIGS. 2 (c) and 5, the skirt wall 50 of the present embodiment has a tab body in which a part 50b of the skirt wall 50 is cut out and the part 50b is cut out. 20 can be attached. That is, when viewed from the side (+ Y direction) in FIG. 2C, a part 50b of the skirt wall 50 is cut out along the circumferential direction so as to be substantially symmetrical with respect to the center of the tab body 20. A first locked portion 51 and a second locked portion 52 are provided at both ends of the skirt wall 50 forming a part of the 50b, respectively.

The first locked portion 51 has a function of restricting the axial movement of the tab body 20 mounted on the skirt wall 50. More specifically, as shown in FIG. 2, the first locked portion 51 in the present embodiment is a pair of upper and lower parts protruding in the radial direction from the skirt wall 50 so as to sandwich the side sleeve portion 21a in the axial direction described above. It is composed of the convex portions 51a and 51b.

In other words, when the tab body 20 is attached to the skirt wall 50, the side sleeve portion 21 is sandwiched between the convex portion 51a and the convex portion 51b in the axial direction, for example, as shown in FIG. 1 (b). Is done. As described above, in the present embodiment, since the first locking portion 21 and the first locked portion 51 are arranged on both sides of the center of the tab main body 20 as a reference, the tab main body 20 including the first locking portion 21 is provided. Is in the shape of a cross, and each side sleeve portion 21a is accommodated in a region surrounded by a pair of convex portions 51a and 51b.

Further, in the present embodiment, in order to prevent the first locking portion 21 from unintentionally detaching from the first locked portion 51, the first locking portion 21 and the first locked portion 51 are mutually connected with each other. A meshing structure is adopted. That is, at the lower end (on the gripping portion 30 side) of the above-mentioned lateral sleeve portions 21a, an engaging projection 21af that protrudes downward in the axial direction when mounted on the skirt wall 50 is formed. There is. On the other hand, of the pair of convex portions 51a and 51b described above, the convex portion 51b located on the lower side in the axial direction is similarly formed with an engaged projection 51bf protruding upward in the axial direction. ..

Therefore, as shown in FIGS. 4A and 4B, when the tab body 20 is attached to the skirt wall 50, the engaging projection 21af gets over the engaged projection 51bf and engages with each other. Become. The protruding lengths of the engaging protrusions 21af and the engaged protrusions 51bf are appropriately adjusted so that the opening tab 40 does not excessively stay on the skirt wall 50 at the time of opening.

The second locked portion 52 has a function of restricting the expansion of the diameter of the tab body 20 in the radial direction of the skirt wall 50 by engaging with the second locking portion 23 described above. More specifically, as shown in FIGS. 2A and 2C, the second locked portion 52 formed on the skirt wall 50 in the present embodiment is a notched part of the skirt wall 50. It is an engaging hook 52a that protrudes outward in the circumferential direction (inside a part of the cutout 50b) from the end portion forming the 50b.

Therefore, as is clear from FIG. 1 (b), when the second locking portion 23 and the second locked portion 52 are engaged with each other, the tab body 20 exerts a function like a fastener and the tab body 20 exhibits a function like a fastener. It is configured so that the skirt wall 50 can be fastened on both sides in the circumferential direction.
In the present embodiment, the second locking portion 23 has a groove shape and the second locked portion 52 has a hook shape, but the combination is not limited to this, and both may have the opposite configuration. It may have a hook shape.

Further, as shown in FIGS. 3 and 5, a screw thread screwed on the inner peripheral surface of the skirt wall 50 in the present embodiment with a screw portion 203 formed on the outer surface 202b of the tubular side wall 202 of the container mouth portion 201. 53 is formed.
Further, on the inner peripheral surface of the skirt wall 50, a plurality of locking projections 54 are formed so as to line up in the circumferential direction below the above-mentioned screw 53 (on the opening side opposite to the top plate 10).

In this embodiment, four locking projections 54 are provided on the inner peripheral surface of the skirt wall 50 at equal intervals in the circumferential direction. The specific shape of the locking projection 54 is not particularly limited, but for example, a part of a screw shape (a protrusion having a predetermined length in the circumferential direction) such as a screw 53 or a first circumferential protrusion 204 described later. An example is an incomplete screw shape in which the tip is gradually thinned so that it can be easily overcome.

Here, the container 200 in the present embodiment will be described with reference to FIG.
The container 200 is, for example, a PET bottle made of synthetic resin, and includes a container mouth 201 to which the screw cap 100 of the present embodiment is wound. Such a container mouth portion 201 includes a tubular side wall 202, a screw portion 203, a circumferential first protrusion 204, and a circumferential second protrusion 205. Although the structure of the container mouth portion 201 or less is not shown, a known structure can be appropriately applied.

The tubular side wall 202 is wound with the screw cap 100 described above, and also functions as an outlet for the contents.
The screw portion 203 is a screw having a known shape formed on the outer surface 202b of the tubular side wall 202, and is a portion that meshes with the screw 53 on the inner peripheral surface of the skirt wall 50 described above at the time of winding.

The circumferential first protrusion 204 is formed on the tubular side wall 202 so that the plurality of locking protrusions 54 described above can be overcome immediately before the completion of winding. Once the locking projection 54 has passed over the circumferential first protrusion 204, the circumferential first protrusion 204 functions as a stopper so that the screw cap 100 does not easily come off.
Further, the circumferential second protrusion 205 is also referred to as a bead and is typically formed on the tubular side wall 202 so as to project more radially than the circumferential first protrusion 204. For example, when the container 200 is manufactured. It is gripped by a transport means (not shown).

In this embodiment, as can be understood by integrating FIGS. 5 and 6, the screw portion 203 is not formed in the vicinity of the upper end portion of the tubular side wall 202, and the inner peripheral surface of the skirt wall 50 corresponds to this. The screw 53 is not formed on the upper side (top plate 10 side) of the above. In particular, as shown in FIG. 6, in the present embodiment, when the locking projection 54 of the skirt wall 50 gets over the first circumferential projection 204 formed on the tubular side wall 202 of the container mouth portion 201, the skirt It is configured so that the meshing between the screw portion 53 of the wall and the screw portion 203 of the container mouth portion 201 is completed.

Therefore, by adopting the above configuration, once the locking projection 54 gets over the first circumferential projection 204, the screw does not mesh even if the screw cap 100 is turned in either the clockwise or counterclockwise direction. It is impossible to open the cap by the correct method other than idling and using the above-mentioned opening tab 40. When the opening tab 40 is used, at least the weakening line WL is broken, so that it is possible to secure the proof of opening (tamper evidence).

In the present embodiment, four locking projections 54 are provided on the inner peripheral surface of the skirt wall 50 at equal intervals in the circumferential direction, but a plurality of locking projections 54 other than the four may be provided, and at least not at equal intervals. One may be unequally spaced. Further, the circumferential second protrusion 205 is not always essential and may be omitted as appropriate.

<Manufacturing method of resin screw cap 100 with tab for opening>
Next, with reference to FIG. 7, a method for manufacturing the resin screw cap 100 with a tab for opening according to the present embodiment will be described.
As described below, in the method of manufacturing the screw cap 100 in the present embodiment, injection molding is performed so that the opening tab 40 is once parallel to the main surface of the top plate 10 (the state shown in FIG. 1A). After that, the opening tab 40 is bent from the peripheral edge of the top plate 10 and the tab main body 20 is attached to a notched part 50b of the skirt wall 50.

That is, first, in step 1, the screw cap 100 is injection-molded with the opening tab 40 extending so as to be parallel to the main surface of the top plate 10. At this time, the above-mentioned components such as the skirt wall 50 and the reinforcing strap 22 are also integrally molded.

Then, in step 2, the weakening line WL is formed when the weakening line WL is not integrally formed in step 1. The weakening line WL is formed, for example, at the upper end 50a of the skirt wall 50. The weakening line WL may be formed on the top plate 10 side instead of the skirt wall 50 side. The length of the weakening line WL in the circumferential direction is not particularly limited, but in consideration of openability and easiness of tearing, at least 90 degrees or more on both sides in the circumferential direction with the center of the bending point of the tab body 20 as the base point as described above. It is preferably formed in the range of (for example, 120 degrees).

As a method for forming the weakening line WL, for example, a known blade is attached to a jig to form the weakening line WL along the circumferential direction. As the weakening line WL, a plurality of breakable bridges WLb arranged intermittently along the circumferential direction may be formed, or a continuous thin-walled (score) line may be formed along the circumferential direction.
If the weakening line WL is formed at the same time in step 1, this step 2 is omitted.

In the following step 3, the tab body 20 is brought close to the notched part 50b of the skirt wall 50 by bending the opening tab 40 with the peripheral edge of the top plate 10 as a base point. At this time, the reinforcing strap 22 connecting the peripheral edge 10 of the top plate 10 and the opening tab 40 is in a tense state due to tensile stress due to the rotation of the opening tab 40.
Therefore, when the tab body 20 of the opening tab 40 is finally attached to the notched part 50b of the skirt wall 50, the reinforcing strap 22 receives the pulling force without slackening, and the weakening line WL The other portion 10a of the peripheral edge of the top plate 10 and the tab body 20 of the opening tab are connected so as to straddle.

Next, in step 4, the opening tab 40 is lowered from the peripheral edge of the top plate 10 and the tab body 20 is attached to the notched part 50b of the skirt wall 50. At this time, the engaging projection 21af of the first locking portion 21 (side sleeve portion 21a) gets over the engaged projection 51bf and becomes engaged. As described above, when the opening tab 40 is attached to the notched part 50b of the skirt wall 50, the first locking portion 21 formed on the tab body 20 engages with the first locked portion 51. By doing so, the movement of the tab body 20 in the axial direction is restricted.

Further, in step 5, the second locking portion 23 (locking groove portion 23a) of the tab body 20 is locked to the second locked portion 52 (engaging hook 52a) of the skirt wall 50. This makes it possible to suppress the unintended radial expansion of the tab body 20 of the skirt wall 50.
It should be noted that step 4 and step 5 are executed substantially in parallel, but the present embodiment is not limited to this, and any of them may be performed first.

According to the synthetic resin screw cap 100 in the present embodiment described above, the cap can be easily opened by using the opening tab 40 with a finger or the like at the time of opening, but the resin makes the hand or the like scratched. There is no risk of sticking, and the first locking portion prevents the opening tab from unintentionally moving in the axial direction and detaching from the skirt wall 50.

The above-described embodiment can be modified in various ways without departing from the spirit of the present invention.
Hereinafter, modifications suitable for this embodiment will be described with reference to the drawings as appropriate. Of the configurations described below, configurations having the same functions as those of the embodiments are assigned the same numbers and the description thereof will be omitted as appropriate.

<Modification 1>
FIG. 8 shows the appearance of the screw cap 100 according to the first modification.
In the above-described embodiment, the first locking portion 21 and the second locking portion 23 are arranged at different positions with respect to the tab body 20, but in the present modification 1, the second locking portion 23 is the first engaging portion. The main difference is that it is integrated with the stop 21.

That is, the first locking portion 21 of this modification, which also serves as the second locking portion 23, intersects the axial direction (Z direction) when mounted on the notched portion 50b of the skirt wall 50 (not shown). The second locking has a side sleeve portion 21a extending in the circumferential direction (θz direction) from the tab body 20 so as to be orthogonal to each other, and further extends downward from the end portion of the side sleeve portion 21a. It has a part 23.

On the other hand, as shown in FIG. 8B, the first locked portion 51 and the second locked portion 52 provided on the skirt wall 50 are also the first locked portion 21 (and the second locked portion 21) described above. The shape corresponds to the shape of the portion 23). More specifically, first, the width of the convex portion 51b in the circumferential direction is the convex portion in the above-described embodiment, corresponding to the fact that the width of the engaging protrusion 21af is reduced by the amount of the second locked portion 23. It is smaller than the width of 51b.

Further, the engaging hook as the second locked portion 52 is not hooked from the radial outside to the second locking portion 23 (locking groove portion 23a) as in the above-described embodiment, and the first locked portion is not hooked. Similar to 51, it is a convex engaging hook that protrudes outward in the radial direction. Therefore, when the second locking portion 23 and the second locked portion 52 in this modification are engaged, the second locked portion 52 is placed between the tab body 20 and the second locking portion 23. It becomes the inserted form.

<Modification 2>
FIG. 9 shows the appearance of the screw cap 100 according to the modified example 2.
In the above-described embodiment, the second locking portion 23 is a through hole, but in this modified example, the main point is that the hole is not a closed hole but a notch in a part. There is a feature.

That is, as shown in FIG. 9A, the second locking portion 23 in this modification has a U-shape with the end portion on the first locking portion 23 side cut out. On the other hand, the second locked portion 52 has the same structure as that of the above-described embodiment. As a result, the second locked portion 52 can be more easily disengaged from the second locking portion 23 at the time of opening, and the load applied to the finger at the time of opening can be reduced.

Even if the configuration according to the modification described above is applied, the effect peculiar to the present embodiment described above can still be enjoyed. It should be noted that these modified examples may be appropriately combined to form a new composite cap having a structure other than that shown in the figure.

It is suitable for providing a cap that maintains high opening property without damaging fingers or the like and yet has sufficient resistance to unintended emergency opening.

10 Top plate 11 Inner ring 12 Outer ring 20 Tab body 21 1st locking part 22 Reinforcing strap 23 2nd locking part 30 Grip part 40 Opening tab 50 Skirt wall 51 1st locked part 52 2nd engaged Stop 53 Screw 54 Locking protrusion 100 Resin screw cap with tab for opening 200 Container 201 Container mouth 202 Cylindrical side wall 203 Screw part 204 Circumferential first protrusion 205 Circumferential second protrusion

Claims (7)

A top plate with an inner ring on the lower surface that adheres to the inner surface of the cylindrical side wall of the container mouth to form a seal, and
A tab body that is bent from a part of the peripheral edge of the top plate and descends along the axial direction, and a tab for opening having a grip portion formed at the bottom of the tab body.
Along with descending from the rest of the peripheral edge of the top plate, the inner peripheral surface includes a skirt wall on which a thread is formed to be screwed with a screw portion formed on the outer surface of the cylindrical side wall of the container mouth portion .
A breakable weakening line is formed in at least a part of the upper end portion of the skirt wall connected to the peripheral edge of the top plate, and a part of the skirt wall is cut out in the cutout part. The tab body can be attached to the
The tab body is formed with a first locking portion that engages with a first locked portion formed on the skirt wall to restrict the axial movement of the tab body .
The first locking portion is composed of lateral sleeve portions extending in the circumferential direction from the tab body so as to intersect the axial direction.
The first locked portion is characterized by being composed of a pair of upper and lower convex portions protruding radially from the skirt wall so as to sandwich the lateral sleeve portion in the axial direction. Resin screw cap with tab for. The first locking portion is composed of lateral sleeve portions extending on both sides in the circumferential direction starting from the tab body so as to intersect the axial direction.
The resin with a tab for opening according to claim 1 , wherein the first locked portion is composed of a pair of upper and lower convex portions arranged on both sides in the circumferential direction with respect to the tab body in the axial direction. Screw cap made. The tab body is formed with a second locking portion that engages with a second locked portion formed on the skirt wall to regulate the diameter expansion of the tab body in the radial direction of the skirt wall. The resin screw cap with a tab for opening according to claim 1 or 2 . 3 . The resin screw cap with the opening tab described in any one of the items. The weakening line is formed so as to extend over 90 degrees on both sides in the circumferential direction from the center of the bending point of the opening tab on the peripheral edge of the top plate.
The resin screw cap with a tab for opening according to claim 4 , wherein the reinforcing strap straddles the vicinity of the center of the weakening line and is connected to the peripheral edge of the top plate. On the inner peripheral surface of the skirt wall, a plurality of locking projections are formed so as to line up in the circumferential direction below the thread .
When the locking projection of the skirt wall gets over the circumferential protrusion formed on the tubular side wall of the container mouth portion, the engagement between the screw portion of the skirt wall and the screw portion of the container mouth portion ends. The resin screw cap with a tab for opening according to any one of claims 1 to 5 . A part of the skirt wall hanging from the peripheral edge of the top plate provided on the lower surface with an inner ring that adheres to the inner surface of the tubular side wall of the container mouth to form a seal is cut out, and the inner peripheral surface of the skirt wall is cut out. A resin with an opening tab is formed in which a screw thread is formed to be screwed with a screw portion formed on the outer surface of the tubular side wall of the container mouth portion, and an opening tab is attached to the notched portion. This is a method for manufacturing screw caps.
A step of forming an opening tab extending from a part of the peripheral edge of the top plate so as to be parallel to the main surface of the top plate.
A step of bending the opening tab in the axial direction starting from the peripheral edge of the top plate so that the opening tab is lowered from the peripheral edge of the top plate and attached to a part of the notched skirt wall. And, including
When the opening tab is attached to a notched portion of the skirt wall, the first locking portion formed on the tab body of the opening tab is the first covering formed on the skirt wall. By engaging with the locking portion, the movement of the tab body in the axial direction is restricted .
The first locking portion is composed of lateral sleeve portions extending in the circumferential direction from the tab body so as to intersect the axial direction.
The first locked portion is composed of a pair of upper and lower convex portions protruding radially from the skirt wall so as to sandwich the side sleeve portion in the axial direction.
A method for manufacturing a resin screw cap with a tab for opening.

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