Tamperproof closing element for beverage containers

Abstract

A closing element of plastic for beverage containers (1) comprises a main body (2) with a circular-cylindrical shape defined by an upper surface (3) and a lower annular liner (4) made in a single piece to enclose an end portion of the container (1). The closing element further comprises a lateral portion having a pair of weakened and/or tear lines (9a, 9b) extending from the free edge (4a) of the annular liner (4) for a length equal to a third dimension ©. The two lines (9a, 9b) are separated, at their end sections, by a first dimension (A) and, at the free edge (4a), by a second dimension (B). The lateral portion (10) defined by the pair of lines (9a, 9b) is acted upon by a tab (11) associated with the annular liner (4) and designed to separate the closing element from the neck (6) so as to open the container. The first dimension (A) of the pair of lines (9a, 9b) is equal to the second dimension (B) calculated at the free edge (4a) from which the tab (11), forming an extension of the lateral portion (10), extends. The extension (L) of the tab (11) outside the limits of the free edge (4a) is greater than the second dimension (B).

Description

TECHNICAL FIELD

The present invention relates to a tamper-evident closing element made of plastic for containers for liquids, in particular for beverages, whether still or carbonated.

BACKGROUND ART

In the field of container closures, that is, caps for plastic or glass bottles, there is an increasing demand for alternative solutions capable of effectively substituting metal crown caps and plastic screw-on caps.

The need for effective alternatives to traditional caps is felt particularly strongly in the field of containers for beverages such as the latest generation beers and soft drinks which are required to be easily opend by hand, but also ale to be re-closed before they are completely consumed. Further, these containers must provide effective “tamper evidence” or “tamper proofing” (that is, a feature of the closure which, if breached or missing, provides evidence to consumers that tampering has occurred) and the feature of not damaging the neckof the container during application or removal of the closure so that, where necessary, the container can be re-used.

At present, the closures for these containers/bottles especially those made of plastic, consist of caps divided broadly into three categories: The first is the traditional screw-on cap (either metal, usually aluminium, or of plastic, usually polyolefin based such as, for example, polyethylene or polypropylene) which, obviously, enable the container to be re-closed after being opened for the first time and (each time it is re-opened thereafter) enable the gas produced by the beverage when the container is opened after shaking to be released into the atmosphere prior to removal of the closure (also known as “venting”). The disadvantages of this type of closure for some applications are its conventional appearance and the fact that the container neck must necessarily be threaded, resulting in a less than optimal drinking surface for the consumer, and additional weight of plastic in the bottle neck.

The second category of cap is a metal cap (usually aluminium) associated with an opening grip ring wrapped around or set alongside the container neck. This type of cap requires little force to apply it to, and remove it from, the container, and it does not damage the neck of the container, which makes it suitable for re-usable bottles. The disadvantages of this type of cap are its high production cost, the impossibility of re-closing the container after opening for the first time and its low safety level since the consumer can, if he or she does not exercise due care in opening, be injured by the resulting sharp edges; as well as the fact that the cap must be removed using both hands.

The third type of cap available on the market is the traditional crown cap, which is the most widespread type of cap on the market thanks to its excellent sealing properties and low cost not only in terms of machinery used to apply it, but also in terms of the product itself.

The disadvantages of the crown cap are due to: the high axial loads on the container when the closure is applied, making it difficult (or impossible) to apply it plastic containers owing to the risk of destroying the container itself during the capping process; the impossibility, or difficulty, of opening the container manually; the impossibility of properly re-closing the container because the cap is irreversibly deformed on opening; and, lastly, the impossibility of re-using the container—if it is made of plastic—since the corrugations and the tightening force applied during capping irremediably scratch the mouth of the container.

To overcome these drawbacks, the Applicant designed and constructed a closing element (see Italian patent application IT BO2000A000139) consisting of a main body with a circular-cylindrical shape defined by an upper surface and a lower annular liner made in a single piece. This type of closing element comprises a lateral portion having a pair of weakened and/or tear lines extending from the free edge of the annular liner for a length equal to a first dimension. The two lines are separated, at their end sections away from the free edge, by a second dimension and, at the free edge, by a third dimension. These three dimensions are calculated as a function of the inside and outside diameters of the container neck and of the pressure, actual or potential, inside the container, so that, following separation of the main body from the container at first-time opening, using a tab and causing partial and/or total breaking of the weakened and/or tear lines, the container can be re-closed, compensating for the pressure, whether actual or potential, inside the container.

This solution, which has proved functional in its basic constructional aspects, has formed the subject matter of numerous tests and studies aimed at improving and optimising the structure of the parts of the closing element to give it a form better suited to the moulding process used for the production of the closing element itself, improving its sealing properties and facilitating the operations of opening and re-closing the container.

DISCLOSURE OF THE INVENTION

The above mentioned aims are achieved by a closing element of plastic for beverage containers comprising a main body with a circular-cylindrical shape and defined by an upper surface and a lower annular liner made in a single piece to enclose an end portion of the container; the closing element further comprises a lateral portion having a pair of weakened and/or tear lines extending from the free edge of the annular liner for a length equal to a third dimension; the two lines are separated, at their end sections, by a first dimension and, at the free edge, by a second dimension; the lateral portion defined by the pair of lines is acted upon by a tab associated with the annular liner and used to separate the closing element from the neck so as to open the container; the first dimension between the two lines is equal to the second dimension calculated at the free edge from which the tab, forming an extension of the lateral portion, extends; the extension of the tab outside the limits of the free edge is greater than the second dimension.

DESCRIPTION OF THE DRAWINGS

The technical characteristics of the invention, with reference to the above aims, are clearly described in the claims below and its advantages are apparent from the detailed description which follows, with reference to the accompanying drawings which illustrate a preferred embodiment of the invention provided merely by way of example without restricting the scope of the inventive concept, and in which:

FIG. 1 is a front view, with some parts cut away in order to better illustrate others, of a tamper-evident closing element. of plastic for containers for liquids according to the present invention;

FIG. 2 is a top plan view, with some parts cut away in order to better illustrate others, of the closing element of FIG. 1;

FIG. 3 is a perspective view of the closing element shown in FIGS. 1 and 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

With reference to the accompanying drawings, and in particular, FIG. 1, the closing element according to the invention, made of a plastic material, is applied to containers 1 for beverages such as beer, tea, soft drinks in general and other similar beverages but without thereby limiting the scope of the inventive concept.

The closing element may be made of any of a number of different types of plastic (without excluding others), such as, for example, polyethylene or polypropylene or a polyester resin such as polyethylene terephthalate or polyethylene naphthalate.

This closing element comprises a main body 2, with a circular-cylindrical shape (or, more specifically, a circular-truncated cone shape), defined by an upper surface 3 and a lower annular liner 4 made in a single piece to enclose an end portion of the container 1 comprising a mouth 5 for dispensing the beverage and defined by the neck 6 of the container 1.

The annular liner 4, comprises, along its inside surface an annular tooth 7, forming an undercut that stably engages a corresponding annular bead 8 on the neck 6 of the container 1.

As illustrated in FIGS. 1, 2 and 3, the closing element according to the invention further comprises a lateral portion 10 defined by weakened and/or tear lines 9a and 9b, which break the tooth 7 and extend from the free edge 4a of the annular liner 4 for a length, labelled C, equal to a third dimension.

In addition to this, the two weakened and/or tear lines 9a and 9b are separated, at their end section away from the free edge 4a, by a first dimension, labelled A, and, at the free edge 4a, by. a second dimension, labelled B.

The lateral portion 10 defined by the pair of weakened and/or tear lines 9a and 9b is acted upon by a tab 11 associated with the annular liner 4 and designed to separate the closing element from the neck 6 so as to open the container by partly or totally breaking the weakened and/or tear lines 9a and 9b.

Still with reference to FIG. 1, the first dimension A between the two weakened lines 9a and 9b is substantially equal to the second dimension B calculated at the free edge 4a from which the tab 11, forming an extension of the lateral portion 10, extends.

Further, the extension L of the tab 11 outside the limits of the free edge 4a is greater than the second dimension B.

The tab 11 comprises a central portion 12 and two lateral wings 13 and 14 together forming a single piece, also with the lateral portion 10.

The lateral wings 13 and 14 extend (see also FIG. 2) in a plane that coincides with the plane in which the free edge 4a extends in such a way as to define an arced extension.

In addition to this, each of the lateral wings 13 and 14 presents at least one bridge 15 and 16 joining it to the free edge 4a and unambiguously indicating that the container 1 has been opened by turning the tab 11 upwardly in such a way as to break the bridges 15 and 16 themselves (as described in more detail below).

As illustrated in FIGS. 2 and 3, the free edge 4a has a pair of sections 17 and 18, each one close to one of the weakened and/or tear lines 9a and 9b.

Each of these two sections 17 and 18 enlarges a portion of the free edge 4a so that the end of it close to the end of the corresponding weakened and/or tear line 9a and 9b protrudes from it, and thus forms one of a pair of levers that facilitate opening of the container 1.

Each of the protrusions 17 and 18 faces one of the lateral wings 13 and 14, each of the latter presenting at least one bridge 15 and 16 joining it to the corresponding protrusion 17 and 18 and unambiguously indicating that the container 1 has been opened when the bridges 15 and 16 themselves have been broken.

Structurally, each of the protrusions which, as stated, forms a manual push surface, close to the corresponding weakened and/or tear line 9a and 9b, in such a way as to enable the container 1 to be opened, and when this is done, breaking the bridges 15 and 16 placed between the wings 13 and 14 and the lower surfaces of the protrusions 17 and 18.

To be able to open the container 1, there is a third weakened line 19 made at the far end of the pair of weakened and/or tear lines 9a and 9b relative to the free edge 4a.

This third weakened line 19 forms a section joining the weakened and/or tear lines 9a and 9b and, in practice, constitutes a hinge line allowing the tab 11 to be turned upwardly in such a way as to open the container 1.

As shown in the drawings, both the third hinge line 19 and the pair of lines 9a and 9b can be made on the outside surface of the annular liner 4. Alternatively, for technical reasons connected with the moulding process and/or the appearance of the closing element, the three lines 9a, 9b, 19 may be made on the inside surface of the annular lining 4, without thereby departing from the scope of the inventive concept.

Constructionally, the third hinge line 19 and the pair of weakened and/or tear lines 9a and 9b define a lateral portion 10 with a substantially rectangular shape.

In practice, the pair of weakened and/or tear lines 9a, 9b may be parallel or, alternatively, they may be divergent, extending from the third hinge line 19 at an angle δ to the perpendicular that is greater than 1° and substantially equal to 2° (see FIG. 1).

As shown in FIG. 1, the aforementioned internal tooth 7 extends circumferentially around the inside surface of the main body 2 through an angle α large enough to position the ends of the tooth 7 close to the weakened and/or tear lines 9a and 9b and in such a way as to enable, in combination with the aforementioned three dimensions A, B and C calculated at least as a function of the diameter D and height H of the container 1 neck 6 and of the pressure, actual or potential, inside the container 1, to enable the container 1 to be re-closed—after first-time opening—while at the same time compensating for the pressure, whether actual or potential, inside the container 1 itself.

Preferably, the angle α of circumferential extension of the internal tooth 7 ranges from 180° to 330°.

Tests have shown that the optimum angle α of circumferential extension of the internal tooth 7 is a value between 270° and 300°, a range that allows a secure seal suitable for the type of pressure, whether actual or potential, inside the container 1.

To complete the zone that holds the closing element to the neck 6, the lateral portion 10 defined by the pair of weakened and/or tear lines 9a and 9b presents a protruding section 20 forming an arced portion of the internal tooth 7.

The protruding section 20 of the tooth 7 extends for an angle β of between 20° and 160°. In this case too, tests have shown that the optimum value of the angle β falls within a range of 30° to 50°.

The security of the seal of the closing element may be completed by adding to an inside portion of the closing element a sealing element 21 acting in conjunction with the internal tooth 7 to enhance the effectiveness of the seal against the pressure, whether actual or potential, inside the container 1 (see FIG. 1) .

The sealing element 21 may be made of plastic and may be moulded on the inside face of the upper surface 3.

Alternatively, the sealing element 21 may be a separate part applied to the inside face of the upper surface 3.

The closing element according to the invention therefore achieves all the preset aims thanks to an extremely simple structure which, considered in its entirety, is more practical and easier to apply and use than other types of closures hitherto available on the market.

Indeed, to remove the closing element, the user first pulls the tab 11 outwards (see arrow F in FIG. 3) to start opening the container 1 by breaking the tamper-evident bridges 15 and 16.

At this point, the user can push one of the surfaces defined by the protrusions 17 and 18 upwards in such a way as to flip the closing element off the neck 6 of the container 1 (see arrow F1 in FIG. 3).

The special design of the closing element enables the container 1 to be securely re-closed, irrespective of the pressure build-up inside it, but at the same time provides clear evidence that it has been opened.

This is accomplished also by the configuration of the two weakened and/or tear lines on the main body of the closing element. In practice, these lines create a break in the surface of the main body and enable control of the circling power of the tooth on the container neck bead according to predetermined angles, this control being exercised by appropriately selecting the dimensions A, B, C, and shape of the opening/re-closing tab.

Thanks to this structure, a single closing element according to the invention meets a range of important technical requirements, namely:

easy, ambidextrous type opening of the container, using one hand only thanks to the presence of the protrusions on both sides of the tab and requiring just a minimum effort to open and push on one of the two protrusions;

immediate, clear evidence that the container has been opened, provided by the weakened and/or tear lines and by the bridges;

possibility of re-closing the container after first-time opening thanks to the dimensions A, B, C, to the configuration of the internal tooth and to the presence of the internal sealing element which permit self-adjustment of the pressure inside the container, not only for artificially carbonated beverages but also for naturally fermented drinks;

possibility of re-using the container thanks to the special structure of the opening means which do not scratch or damage the the part of the container neck covered by the closing element;

It will be understood that the invention can be subject to modifications and variations without thereby departing from the scope of the inventive concept. Moreover, all the details of the invention may be substituted by technically equivalent elements

Claims

1. A closing element of plastic for beverage containers (1) comprising a main body (2) with a circular-cylindrical shape, that is, a circular-truncated cone shape, defined by an upper surface (3) and a lower annular liner (4) made in a single piece to enclose an end portion of the container (1) comprising a mouth (5) for dispensing the beverage and defined by the neck (6) of the container (1); the annular liner (4) comprising, along its inside surface a tooth (7), forming an undercut that stably engages a corresponding annular bead (8) on the neck (6) of the container (1); the closing element further comprising a lateral portion having a pair of weakened and/or tear lines (9a, 9b) extending. from the free edge (4a) of the annular liner (4) for a length equal to a third dimension (C); the two lines (9a, 9b) being separated, at their and sections, by a first dimension (A) and, at the free edge (4a), by a second dimension (B); the lateral portion (10) defined by the pair of lines (9a, 9b) being acted upon by a tab (11) associated with the annular liner (4) and designed to separate the closing element from the neck (6) and to partially or completely break the weakened and/or tear lines (9a, 9b); the closing element being characterised in that the first dimension (A) of the pair of lines (9a, 9b) is equal to the second dimension (B) calculated at the free edge (4a) from which the tab (11), forming an extension of the lateral portion (10), extends; the extension (L) of the tab (11) outside the limits of the free edge (4a) being greater than the second dimension (B).

2. The closing element according to claim 1, characterised in that the tab (11) comprises a central portion (12) and two lateral wings (13, 14) together forming a single piece, also with the lateral portion (10); the lateral wings (13, 14) extending in a plane that coincides with the plane in which the free edge (4a) extends.

3. The closing element according to claims 1 and 2, characterised in that each of the lateral wings (13, 14) presents at least one bridge (15, 16) joining it to the free edge (4a) and unambiguously indicating that the container (1) has been opened by breaking the bridges (15, 16) themselves.

4. The closing element according to claim 1, characterised in that the free edge (4a) has a pair of sections (17, 18), each one close to one of the weakened and/or tear lines (9a, 9b) and enlarging a portion of the free edge (4a) so that the end of it close to the end of the corresponding weakened and/or tear line (9a, 9b) protrudes from it, and thus forms one of a pair of levers that facilitate opening of the container (1).

5. The closing element according to claims 1 and 2, characterised in that the free edge (4a) has a pair of sections (17, 18), each one close to one of the weakened and/or tear lines (9a, 9b) and enlarging a portion of the free edge (4a) so that the end of it close to the end of the corresponding weakened and/or tear line (9a, 9b) protrudes from it and faces the related lateral wing (13, 14) that presents at least one bridge (15, 16) joining it to the related protrusion and unambiguously indicating that the container (1) has been opened by breaking the bridges (15, 16) themselves.

6. The closing element according to claim 4, characterised in that each of the protrusions (17, 18) defines a transversal extension of the free edge (4a) in such a way as to form a manual push surface, close to the corresponding weakened and/or tear line (9a, 9b) enabling the container (1) to be opened.

7. The closing element according to claim 5, characterised in that each of the protrusions (17, 18) defines a transversal extension of the free edge (4a) in such a way as to form a manual push surface, close to the corresponding weakened and/or tear line (9a, 9b) and having one of the bridges (15, 16) located between the wing (13, 14) and a lower surface of the protrusion (17, 18).

8. The closing element according to claim 1, characterised in that the far end of the two weakened and/or tear lines (9a, 9b) relative to the free edge (4a) presents a third weakened line (19), forming a section joining the weakened and/or tear lines (9a, 9b) and constituting a hinge line allowing the tab (11) to be turned upwardly in such a way as to open the container (1).

9. The closing element according to claims 1 and 8, characterised in that the third hinge line (19) is made on the outside surface of the annular liner (4).

10. The closing element according to claims 1 and 8, characterised in that the third hinge line (19) is made on the. inside surface of the annular liner (4).

11. The closing element according to claim 1, characterised in that the two weakened and/or tear lines (9a, 9b) are made on the outside surface of the annular liner (4).

12. The closing element according to claim 1, characterised in that the two weakened and/or tear lines (9a, 9b) are made on the inside surface of the annular liner (4).

13. The closing element according to claim 1, characterised in that the third hinge line (19) and the pair of weakened and/or tear lines (9a, 9b) define a lateral portion (10) that is substantially rectangular in shape.

14. The closing element according to claim 1, characterised in that the two weakened and/or tear lines (9a, 9b) are parallel to each other.

15. The closing element according to claim 1, characterised in that the two weakened and/or tear lines (9a, 9b) are divergent, extending from the third hinge line (19) at an angle (δ) to the perpendicular that is greater than 1°.

16. The closing element according to claim 1, characterised in that the internal tooth (7) extends circumferentially around the inside surface of the main body (2) through an angle (α) large enough to position the ends of the tooth (7) close to the weakened and/or tear lines (9a, 9b) and in such a way as to enable, in combination with the aforementioned three dimensions (A, B, C) calculated at least as a function of the diameter (D) and height (H) of the container (1) neck (6) and of the pressure, actual or potential, inside the container (1) to enable the container (1) to be re-closed after first-time opening while at the same time compensating for the pressure, whether actual or potential, inside the container (1) itself.

17. The closing element according to claim 16, characterised in that the angle (α) of circumferential extension of the internal tooth (7) ranges from 180° to 330°.

18. The closing element according to claim 17, characterised in that the angle (α) of circumferential extension of the internal tooth (7) ranges from 270° to 300°.

19. The closing element according to claim 1, characterised in that the lateral portion (10) defined by the pair of weakened and/or tear lines (9a, 9b) presents a protruding section (20) forming an arced portion of the internal tooth (7) to enable the container to be closed.

20. The closing element according to claim 19, characterised in that the protruding section (20) of the internal tooth (7) extends for an angle (β) that ranges from 20° to 160°.

21. The closing element according to claim 20, characterised in that the protruding section (20) of the internal tooth (7) extends for an angle (β) that ranges from 30° to 50°.

22. The closing element according to claim 1, characterised in that an inside portion of the closing element itself has a sealing element (21) that acts in conjunction with the internal tooth (7) to provide a seal against the pressure, whether actual or potential, inside the container (1).

23. The closing element according to claims 1 and 22, characterised in that the sealing element (21) is made of plastic and moulded at least on the inside face of the upper surface (3).

24. The closing element according to claims 1 and 22, characterised in that the sealing element (21) is made of plastic and is a separate part applied at least on the inside face of the upper surface (3).