Technical Field

The present invention relates to a plastic tethered stopper for bottle.

Background

The present invention relates to the field of liquid packaging, wherein it is very common to seal the aperture of a container with a stopper as “caps”.

Such a container is an individual object. The container is usually made of plastic, glass or metal material. The container can be a bottle filled with a fluid or a liquid, especially of a food or a cosmetic product.

The includes a neck at a top part where the bottle neck comprises a peripheral wall and at a top end an aperture through which the bottle is filled and emptied. The aperture is sealed by a stopper.

Such a stopper can be made of metal or plastic material. The stopper is made of one or several piece(s). A plastic stopper is mainly obtained through a molding process. Other parts or elements of the stopper are created into the plastic piece through a cutting or slitting step during the manufacturing process, after molding.

Such a stopper globally has a tubular or cylindrical shaped body closed at its top edge by a roof wall. The stopper body comprises a closure shell bottomly attached to a tamper band (so called “tamper evident band”) through a weakness line. Such weakness line is made of bridges, distributed around the closure shell and the tamper band. Thus, the bridges link the closure shell and the tamper band together. Moreover, the bridges are made when molding the stopper or after molding through a cutting step.

Moreover, in a container sealing position of the stopper, the tamper band is secured around said container neck through a hoop or beads. Such hoop or beads are attached at the bottom of the tamper band. The hoop or the beads inwardly extend relating to the inner wall of the tamper band. In a stopper sealing position, the hoop or beads cooperate under a tamper evident ring outwardly extending from the outer wall of the neck. So, the hoop or beads of the tamper band come in support from bottom to top against the tamper evident ring of the container neck.

Such hoop is so called “folded band”, due to the stopper fabrication process by molding, wherein the stopper is released from a central core of a mold and the hoop downwardly extend relating to the tamper band. Then, the hoop must be reverted inside the stopper, from bottom to top, to get into an inward position relating to the tamper band and the stopper where the hoop will cooperate with the tamper evident ring when the stopper is engaged to seal the container. When the hoop is folded in the inward position, the stopper is placed on the container neck in order to seal it.

Where the tamper band includes beads, the beads are molded on the interior surface of the tamper evident band such as to provide a locking of the tamper band against the container neck. Specifically, the beads are molded, using a fabrication process, such that the beads inwardly extend to come in contact with the neck of the container, into a locking position against the tamper evident ring of the neck.

In order to engage the stopper to seal the container, its neck comprises outer fixation feature, such as thread(s) for screw type stopper. As known, according to a screw type stopper, the closure shell comprises inner thread(s) arranged inside side walls. The container neck fixation feature comprises outer thread(s). Such combination of outer and inner thread(s) allows the stopper to be screwed on the container neck to seal said container and unscrewed for container entirely opening.

Usually, the closure shell is removable. During container or bottle opening, when user unscrews the closure shell of the stopper, the folded band blocks the tamper band against the underside of the bottle tamper evident ring, until the bridges of the weakness line are torn apart from the closure shell, so it is separated from the bottle. After opening, the closure shell can stay attached to the tamper band secured on the container neck through a link. Such stopper is so called a “tethered stopper”.

Known tethered stoppers have at least one link with a bottom end connected to the tamper band and a top end connected to the closure shell. Such link is made into the stopper body, along its periphery, either into the tamper band and/or the closure shell. Moreover, the link is separately fixed along its length to the tamper band through a bottom weakness line and to the closure shell through a top weakness line.

As previously mentioned, the bottom and top weakness lines are made of bridges, respectively bottom bridges and top bridges. The bottom and top weakness lines are made through a slitting or cutting step. Moreover, the slitting or cutting is radially made by blades into a transverse direction from outside to inside the stopper, by applying a rotation movement to the stopper against a cutting edge of each of the blades, which are fixed. Usually the cutting edge are curved but can also be straight.

It is to be noticed that the rotation movement is usually applied to the stopper through knurls, managed around the stopper body, especially outwardly extending around the periphery of the closure shell. Such knurls also further facilitate the hand gripping of the consumer when opening the bottle by unscrewing the closure shell. Usually each blade includes a cutting edge having a thickness greater than or equal to the body thickness of the stopper to slit or cut, to entirely cut through the body thickness (i.e., the width from outside to inside). Specifically, the blade is sufficiently dimension such that allows cutting through the entire thickness of the tamper band (i.e., thru cut).

In order to manage the bridges, each blade cutting edge has several notches, located along the blade edge relative to the position of the bridges to be managed into the stopper body. Moreover, the cutting edge has a slot, longer than a notch, located along the corresponding blade relative to the position of the bottom end or the top end of the link to be managed. In other words, the slot allows no slitting or no cutting along an angular portion of the stopper body, the angular portion corresponding to the bottom end or the top end of the link to be maintained respectively with the tamper band or with the closure shell.

Especially there are offset along the cutting edge at each extremity of the slit, each of the offsets has a shift edge radially separating the cutting edge protruding relative to the inside of the slit. The slit inside has an inner wall which is not sharp to avoid slitting or cutting.

According to a known configuration of blades, the offsets are managed in a sharp way, the offset edge extending orthogonally relative to the cutting edge and relative to the slit inner wall. Thus, when cutting, the square orientation of the offsets provides a straight cut located on each side of the bottom end or at the top end of the link. Such straight cut is detrimental to the integrity of the corresponding link end, which is required to maintain the tethered link of the closure shell with the tamper band secured on the bottle neck. In other words, the straight cut manages weakness points, which are likely facilitating the tearing and breaking of the tethered link.

Summary of Invention

An object of the present invention is to improve a tethered stopper for bottle with a bottom end and/or a top end of the link with more resistant sides, avoiding too weak tearing and breaking. Therefore, such tethered stopper comprises end sides managed along specific orientations, different compared to the known end sides (which are straight and in a square way, into the known radially and orthogonally direction, and through the known entire thickness of the stopper body). The specific orientations confer smooth or gentle characteristics to the end sides along angular portions.

According to the invention, the tethered stopper for bottle comprises a tamper band, a closure shell, and a tethered link managed between the tamper band and the closure shell. Two weakness lines separably connect the tethered link to the tamper band and the closure shell. The tethered link further comprising two ends, the two ends linking the tethered link respectively to the tamper band and to the closure shell, each of the two ends having an arc-like shape defined by the perimeter of the tamper band and comprising two sides located approximately opposite to each other relative to the arc shape, the two sides delimiting an angular length of each of the two ends.

At least one of the two sides of one of the two ends comprises

- a first angular portion connected to the one of the two ends, the first angular portion comprising a depth less than a thickness of the tamper band, the first angular portion depth being equal along the first angular portion, and

- a second angular portion connected at an extremity to the first angular portion and opened at an opposite extremity to the one of the two weakness lines, the second angular portion being inclined from the first angular portion to the one of the two weakness lines.

At least one of the two sides of the other of the two ends comprises

- the first angular portion connected to the other of the two ends, the first angular portion comprising a depth less than a thickness of the tamper band, the first angular portion depth being equal along the first angular portion, OR

- the first angular portion connected to the other of the two ends, the first angular portion being inclined from the other of the two ends to the other of the two weakness lines.

According to an embodiment, at least one of the two sides of the other of the two ends comprises, the first angular portion connected to the other of the two ends, the first angular portion comprising a depth less than a thickness of the tamper band, the first angular portion depth being equal along the first angular portion.

Additionally, the second angular portion connected to the other of the two ends, the second angular portion being inclined from the first angular portion to the other of the two weakness lines.

According to an embodiment, each of the two sides of each of the two ends comprises the first angular portion and the second angular portion.

According to an embodiment, the one of the two weakness lines is a top or a bottom weakness line, the one of the two ends is a bottom end, the other of the two weakness lines is a top weakness line, the other of the two ends is a top end. According to an embodiment, the bottom end and the top end are approximately located diametrically opposite to each other.

According to an embodiment, the first angular portion is located outside the stopper,

- the second angular portion is extending inwardly relative to the stopper from the first angular portion. According to an embodiment, the first angular portion is located inside the stopper, the second angular portion is extending outwardly relative to the stopper from the first angular portion.

According to an embodiment, the first angular portion has a depth of cut that is up to 90% of the thickness of the tamper band. According to an embodiment, the first angular portion has an angular length from 5° to 60°, and in a particular embodiment an angular length from 5° to 20°.

According to an embodiment, the second angular portion has a linear wall. According to an embodiment, the second angular portion has a curved wall, especially a concave wall.

According to an embodiment, the second angular portion has an angular length from 5° to 60°, and in a particular embodiment an angular length from 5° to 20°.

According to an embodiment, the angular length of the one of the two ends is greater than the angular length of the other of the two ends.

According to an embodiment, the angular length of the other of the two ends is greater than the angular length of the one of the two ends. According to an embodiment, the angular length of the one of the two ends is equal to the angular length of the other of the two ends.

Brief description of the Drawings

The invention can be better understood on reading the following description given merely by way of example and with reference to the accompanying drawings.

FIG. 1 is a perspective view of an embodiment of a tethered stopper according to the invention.

FIG. 2 is a front view of the FIG. 1.

FIG. 3 is cross section view along an axis A-A' from top to bottom of the FIG. 2.

FIG. 4 is a cross section view along an axis B-B' from top to bottom of the FIG. 2.

FIG. 5 is a detailed partial cross section view of FIG. 3 on the left and FIG. 4 on the right, respectively showing the shape of the bottom end on the left and the shape of the top end on the right.

FIG. 6 is a similar view of FIG. 5 of a second embodiment, especially showing on the right each side of the top end with only a first angular portion with a regular depth.

FIG. 7 is a similar view of FIG. 5 of a third embodiment, especially showing on the right each side of the top end with only a first angular portion which is inclined inwardly relative to the stopper.

FIG. 8 is a similar view of FIG. 5 of a fourth embodiment, especially showing only one left side of the two sides of the two ends, while the other opposite side of the two sides extending radially and orthogonally.

FIG. 9 is a similar view of FIG. 5 of a fifth embodiment, especially showing on the left a second angular portion with a curved concave wall; and

FIG. 10 is a similar view of FIG. 5 of a fifth embodiment, especially showing and inside first angular portion and an outward second angular portion.

Description of Embodiments

The present invention relates to a tethered stopper 1, so called “tethered stopper” or “stopper”. Such a stopper 1 is dedicated to close and seal the aperture of a container, such as a bottle. Stoppers 1 are also usually named “caps.” The stopper 1 can be made of any material, such as a metal or plastic material.

The stopper 1 comprises a body made of one or several piece(s). A stopper 1 is mainly manufactured through a molding process. Other parts or elements of the stopper 1 are created into the plastic piece during the manufacturing process, after molding, through a cutting or slitting step, so called “slitting/cutting”. Such stopper 1 globally has a tubular or cylindrical shaped body closed at its top edge by a roof wall 2.

According to an embodiment, such as visible in the example of FIG. 1 , the closure shell 4 of the stopper 1 comprises knurls 40. The knurls 40 extend vertically along the outer wall of the closure shell 4. Such knurls 40 facilitate the hand gripping of the consumer when opening the bottle by unscrewing the closure shell 4. The knurls 40 also allow the rotation movement usually applied to the stopper 1 during slitting/cutting operations.

According to the invention, the stopper 1 comprises a closure shell 4. So, the roof wall 2 is a top part of the closure shell 4. Moreover, the closure shell 4 is bottomly attached to a tamper band 6 (also called “tamper evident band”).

As the stopper 1 is a “tethered stopper”, the stopper 1 comprises a tethered link 8. The tethered link 8 connects the tamper band 6 and the closure shell 4. Therefore, the stopper 1 comprises two weakness lines 10,12, especially a bottom weakness line 10 and a top weakness line 12. The two weakness lines 10,12 separably connect the tethered link 8 to the tamper band 6 and the closure shell 4. So, the tethered link 8 is managed along and between the two weakness lines 10,12.

According to an embodiment, the weakness lines 10,12 include bridges 100,120, distributed around the perimeter of the closure shell 4 and the tamper band 6. Specifically, the bottom weakness line 10 includes bottom bridges 100, while the top weakness line 12 includes top bridges 120. So, the bridges 100,120 seperably connect the closure shell 4 and the tamper band 6 to the tethered link 8 respectively. Specifically, the bottom bridges 100 link the top of the tamper band 6 to the bottom of the tethered link 8, while the top bridges 120 link the bottom of the closure shell 4 to the top of the tethered link 8. Moreover, the bridges 100,120 are distributed around the perimeter of the stopper 1 along their respective weakness line 100,120, having regularly spaced intervals between the bridges 100,120 or not. The bridges 100,120 are made when molding the stopper 1 or after molding by slitting/cutting.

When opening the bottle sealed by the stopper 1 , the closure shell 4 is removed, while the tamper band 6 remains secured on the bottle neck. During opening, the bridges 100,120 of the weakness lines 10,12 are torn apart, releasing the closure shell 4 which remains attached to the tamper band 6 thanks to the tethered link 8.

Therefore, as aforementioned, in a bottle sealing position of the stopper 1, the tamper band 6 is secured around the bottle neck through a hoop 14 or beads. Such hoop 14 is especially visible in FIG. 1. The hoop 14 or beads are attached at the bottom of the tamper band 6. The hoop 14 or the beads inwardly extend relating to the inner wall of the tamper band 4. In the stopper sealing position, the hoop 14 or beads cooperate under a tamper evident ring outwardly extending from the outer wall of the bottle neck. So, the hoop 14 or beads of the tamper band 6 come in support from bottom to top against the tamper evident ring of the bottle neck.

According to an embodiment, where the tamper band 4 comprises such a hoop 14, so called “folded band”, due to the stopper fabrication process by molding, wherein the stopper 1 is released from a central core of a mold and the hoop 14 downwardly extends relating to the tamper band 4, such as visible in FIG. 1. Then, the hoop 14 is reverted inside the stopper 1, from bottom to top, to get into an inward position relating to the tamper band 6 and the stopper 1, where the hoop 14 will cooperate with the tamper evident ring of the bottle neck when the stopper 1 is engaged to seal the bottle. Once the hoop 14 is folded in the inward position, the stopper 1 is placed on the bottle neck in order to seal it.

According to another embodiment, where the tamper band 4 comprises beads, the beads are molded on the interior surface of the tamper evident band 4, in order to provide a locking of the tamper band 4 against the container neck. Specifically, the beads are molded, using a fabrication process, such that the beads inwardly extend to come in contact with the neck of the container, into a locking position against the tamper evident ring of the neck. In order to engage the stopper 1 to seal the bottle, the bottle neck comprises outer fixation feature, such as thread(s) for screw type stopper.

According to a screw type stopper, the closure shell 4 comprises inner thread(s) arranged inside and around an inner wall of the closure shell 4. The bottle neck fixation feature comprises outer thread(s). Such a combination of outer and inner thread(s) allows the stopper 1 to be screwed on the bottle neck to seal said bottle, and reversely unscrewed for bottle opening. Thus, as the closure shell 4 is removable, during bottle opening, when user unscrews the closure shell 4 of the stopper 1, the folded hoop 14 or beads block the tamper band 6 against the underside of the bottle tamper evident ring, until the bridges 100,120 of the weakness lines 10,12 are torn apart from the closure shell 4, so that the closure shell 4 is partially separated from the tamper band 6, except at the tethered link 8, and can be disengaged from the bottle neck. After opening, the closure shell 4 remains attached to the tamper band 6 secured on the bottle neck through the tethered link 8.

According to the invention, the tethered link 8 further comprises two ends 16,18, especially a bottom end 16 and a top end 18. The two ends 16,18 link the tethered link 8 respectively to the tamper band 6 and to the closure shell 4, so that after opening the closure shell 4 remains attached to the top end 18 of the tethered link 8, while the opposite bottom end 16 remains attached to the tamper band 6.

Moreover, each of the two ends 16,18 have an arc-like shape defined by the perimeter of the tamper band 6. Each of the two ends 16,18 comprises two sides 160,162/180,182 respectively located approximately opposite to each other relative to the arc shape. Specifically, the bottom end 16 comprises a left bottom side 160 and a right bottom side 162, while the top end 18 comprises a left top side 180 and a right top side 182. Thus, the sides 160,162/180,182 delimit an angular length 164,184 of each of the two ends 16,18. Especially the two bottom sides 160,162 delimits the bottom angular length 164 of the bottom end 16, while the two top sides 180,182 delimits the top angular length 184 of the top end 18. The angular length 164,184 is represented in FIGs. 3 and 4 by dotted lines.

According to an embodiment, the angular length 164 (or 184) of the one of the two end 16 (or respectively 18) is greater than the angular length 184 (or respectively 164) of the other of the two ends 18 (or respectively 16). In other words, the bottom end 16 is longer than the top end 18, or reversely.

Also, according to another embodiment, the angular length 184 (or 164) of the other of the two ends 18 (or 16) is greater than the angular length 164 (or 184) of the one of the two ends 16 (or 18). According to a specific embodiment, the angular length 164 (or 184) of the one of the two ends 16 (or 18) is equal to the angular length 184 (or 164) of the other of the two ends 18 (or 16). In other words, the angular lengths 164,184 of the ends 16,18 are the same, or approximately the same, such as visible for example in FIGs. 3 to 9.

According to the invention, the tethered stopper 1 improves the ends 16,18 of the tethered link 8 with more resistant sides 160,162/180,182, avoiding too weak tearing and breaking. Therefore, such stopper 1 comprises ends 16,18 with sides 160,162/180,182 managed along specific orientations, in order to confer smooth or gentle characteristics to said sides 160,162/180,182.

Therefore, according to an embodiment of the stopper 1, at least one of the two sides 160,162 (or 180,182) of one of the two ends 16 (or 18) comprises a first angular portion 20 connected to the one of the two ends 16 (or 18). Moreover, the first angular portion 20 comprises a depth less than a thickness of the tamper band 6. For example, the depth of the first angular portion 20 can be comprised between 0,1 and 1 millimeter (mm). Moreover, the depth of the first angular portion 20 is equal along said first angular portion 20. In other words, the first angular portion 20 is alike a round slit managed into one end 16 (or 18), with an inner wall extending at a same distance than the outer or inner periphery of the stopper 1 , especially than the outer wall or inner wall of the tamper band 6.

In some embodiments the first angular portions 20 made by cutting to the material to a depth that is equidistant through the portion 20 (i.e., the depth of the cut is the same across section 20).

Moreover the at least one of the two sides 160,162 (or 180,182) of one of the two ends 16 (or 18) also comprises a second angular portion 22 connected at an extremity to the first angular portion 20 and opened at an opposite extremity to the one of the two weakness lines 10 (or 12). The second angular portion 22 is also inclined from the first angular portion 20 to the one of the two weakness lines 10 (or 12). In other words, the second portion 22 extends from the first portion 20 till crossing the entire thickness of the stopper 1.

Thus at least one side 160,162 (or 180,182) of the end 16 (or 18) comprises a first angular portion 20 and a second angular portion 22. Especially, only one of the two sides 160,162 (or 180,182) of the end 16 (or 18) comprises a first angular portion 20 and a second angular portion 22, such as visible in FIG. 8 on the right showing the bottom end 16. Thereby, the combination of the equal first angular portion 20 and of the inclined second angular portion 22 confers such an area of transition that prevents tearing of the tethered link along a perpendicular direction. Specifically, the inclined second angular portion 22 prevents tearing that would occur along a perpendicular direction to the area located adjacent the ends 16,18 regarding the known method.

Concerning the other of the two ends, according to alternative embodiments, at least one of the two sides 180,182 (or 160,162) of the other of the two ends 18 (or 16) comprises the first angular portion 20 connected to the other of the two ends 18 (or 16). Moreover, the first angular portion 20 comprises a depth less than a thickness of the tamper band 6 and said depth of the first angular portion 20 is equal along said first angular portion 20. In some embodiments, the first angular portion 20 is angled such that it meets the second angular portion 22 on one side and the hinged portion of end 16, 18 at the other side. The angular portion 20 is so dimensioned as to prevent an area of weakness at the location where the cut meets the end 16,18 on the other end. The depth of cut for the angular portion can depend on the material of the tamper band. For example, tamper band material can be cut through 50-90% of the thickness of the tamper band. The depth of the cut can also vary along the first angular portion 20. For example, at the area adjacent the hinged portion of end 16,18, the first angular portion 20 can have thickness that is 10% of the thickness of the tamper band 6 and increases (linearly or otherwise) to a cut depth that is 30% where it adjoins with the second angular section 22.

For materials with lower stiffness and strength characteristics, the depth of cut for the angular portions 20,22 can for example be between 10-50% of the thickness of the tamper band. However, for materials with higher stiffness and strength characteristics (e.g., polypropylene -PP), the depth of cut for the angular portions 20, 22 can be up to 90%.

So, according to such embodiment, at least one of the two sides of one of the two ends comprises the first angular portion 20 connected to the one of the two ends, the first angular portion depth being inclined with a first angle along the first angular portion, while the second angular portion 20 being inclined with a second angle from the first angular portion 20 to the one of the two weakness lines. Moreover, the first angle is less than the second angle, Then at least one of the two sides of the other of the two ends comprises the first angular portion depth being inclined along the first angular portion.

Alternatively, the first angular portion being inclined from the other of the two ends to the other of the two weakness lines. So, the first angular section 20 has a slighter first angle than the second angle of the second angular portion 22. According to an embodiment, when the first angular portion 20 is inclined, the depth of the first angular portion 20 varies linearly along the first angular portion 20.

Alternatively, at least one of the two sides 180,182 (or 160,162) of the other of the two ends 18 (or 16) comprises the first angular portion 20 connected to the other of the two ends 18 (or 16). Moreover, the first angular portion 20 is inclined from the other of the two ends 18 (or 16) to the other of the two weakness lines 12 (or 10).

In other words, one or two sides 180,182 (or 160,162) of the other end 18 (or 16) comprises only one angular portion, so the first angular portion 20, which can be arc shaped with the same depth along it length, such as visible in FIG. 6, or which can be inclined (in the same way or a different way regarding the second angular portion 22 of the corresponding end 16 (or 18), such as visible on FIG. 7. According to another embodiment, at least one of the two sides 180,182 (or 160,162) of the other of the two ends 18 (or 16) comprises the first angular portion 20 connected to the other of the two ends 18 (or 16), the first angular portion 20 comprising a depth less than a thickness of the tamper band 4 and said depth of first angular portion 20 being equal along said first angular portion 20. For example, the depth of the first angular portion 20 is between 10% to 50% of the thickness of the tamper band 6, and the depth of the second angular portion 22 is extends respectively from 50% to 100% of the thickness of the tamper band 6.

Moreover the at least one of the two sides 180,182 (or 160,162) of the other of the two ends 18 (or 16) comprises the second angular portion 22 connected to the other of the two ends 18 (or 16), the second angular portion 22 being inclined from the first angular portion 20 to the other of the two weakness lines 12 (or 10).

In other words, one or two sides 180,182 (or 160,162) of the other end 18 (or 16) comprises a first angular portion 20 which is arc shaped with the same depth along the arc shape, and also comprises the second angular portion which is inclined.

Especially, only one of the sides 180,182 (or 160,162) of the other end 18 (or 16) comprises a first angular portion 20 which is arc shaped with the same depth along the arc shape, and also comprises the second angular portion which is inclined, such as visible in the example of FIG. 8, showing, on the left, a left bottom side 160 of the bottom end 16 with a first angular portion 20 and a second angular portion 22, while the right bottom side 162 is extending radially, whereas on the right, a left top side 180 of the top end 18 with a first angular portion 20 and a second angular portion 22, while the right top side 182 is extending radially.

According to an embodiment, each of the two sides 160,162 (or 180,182) of one end 16 (or 18) comprises the first angular portion 20 and the second angular portion 22. In other words, there are the first angular portion 20 and the second angular portion 22 on both left and right sides 160,162 (or 180,182) of the end 16 (or 18). So, the other end 18 (or 16) can have one or two sides 180,182 (or 160,162) with any shape.

According to a preferred embodiment, each of the two sides 160, 162/, 180, 182 of each of the two ends 16,18 comprises the first angular portion 20 and the second angular portion 22. In other words, there are the first angular portion 20 and the second angular portion 22 on both left and right sides 160,162 of the end 16 and also on both left and right sides of the end 18. According to an embodiment, in order to give more precision, the one of the two weakness lines 10,12 is a bottom weakness line 10 and the one of the two ends 16,18 is a bottom end 16, while the other of the two weakness lines 10,12 is a top weakness line 12 and the other of the two 16,18 ends is a top end 180. Such embodiment is especially visible on the examples of FIGs. 1 and 2, wherein the bottom weakness line 10 is extending along an axis A-A', while the top weakness line 12 is extending along an axis B-B'.

Reversely, according to a different embodiment, the one of the two weakness lines 10,12 is a top weakness line 12 and the one of the two 16,18 ends is a top end 18, while the other of the two weakness lines 10,12 is a bottom weakness line 10 and the other of the two ends 16,18 is a bottom end 16.

According to an embodiment, such as visible on the examples of FIGs. 3 and 4, the bottom end 16 and the top end 18 are approximately located diametrically opposite to each other.

According to an embodiment, the first angular portion 20 is located outside the stopper 1. Moreover, the second angular portion 22 is extending inwardly relative to the stopper 1 from the first angular portion 20. So, the second angular portion 22 is inclined from outside to inside the stopper 1. Such outside first angular portion 20 and such inward second angular portion 22 are visible in the examples of FIGs. 3 to 9.

According to another embodiment, the first angular portion 20 is located inside the stopper 1. Moreover, the second angular portion 22 is extending outwardly relative to the stopper 1 from the first angular portion 20. So, the second angular portion 22 is inclined from inside to outside the stopper 1. Preferably, the inside first angular portion 20 and the outward second angular portion 22 are made by molding.

According to an embodiment, the first angular portion 20 is made by molding or slitting/cutting. According to an alternative or combined embodiment, the second angular portion 22 is made by molding or slitting/cutting.

Concerning some of the dimensions of the stopper 1 , according to an embodiment, the first angular portion 20 has a depth up to 50% of the thickness of the tamper band 4.

According to an embodiment, the first angular portion 20 has an angular length from 5° to 60°. According to a preferred embodiment, the first angular portion 20 has an angular length from 5° to 20°.

According to an embodiment, the second angular portion 22 has an angular length from 5° to 60°. According to a preferred embodiment, the second angular portion 22 has an angular length from 5° to 20°.

According to an embodiment, the second angular portion 20 has a linear wall, such as visible in the examples of FIGs. 3 to 8. According to another embodiment, the second angular portion 22 has a curved wall. In other words, the curved wall of the second angular portion 22 is concave or convex. According to a specific embodiment the second angular portion 22 has a concave wall, such as visible in the example of the FIG. 9.