WO2008072981A2

WO2008072981A2 - Improvements in and relating to tamper evident seals

Info

Publication number: WO2008072981A2
Application number: PCT/NZ2007/000355
Authority: WO
Inventors: Graeme Ashley Blake
Original assignee: Vin Singlz Ltd
Current assignee: Vin Singlz Ltd
Priority date: 2006-12-11
Filing date: 2007-12-11
Publication date: 2008-06-19
Anticipated expiration: 2009-06-11
Also published as: WO2008072981A3

Abstract

A tamper evident seal for use in conjunction with a screw top container. The seal comprises a ring which is frangibly linked to a cap, lid or closure device suitable for use with the container. One or more protrusions extend inwardly from the ring and/or one or more recesses are provided about an inside diameter of the ring. The or each inwardly extending protrusion or recess is adapted to pass through or about a corresponding recess or recesses and/or protrusion or protrusions of a seal capturing feature on the neck of the container when the cap, lid or closure device is initially fitted onto the container.

Description

Improvements in and relating to Tamper Evident Seals

FIELD OF THE INVENTION

This invention relates to tamper evident seals for use with screw top containers, and in particular, but not exclusively to tamper evident seals for use with a combined drinking vessel and cap for a drinks container.

BACKGROUND

The applicant of the present invention is also the applicant of the New Zealand patent application numbers 527195, 538172 and 551470, and has been involved in the development of packaging systems for single serve drinks for a number of years. The present invention relates to an improved tamper evident seal for use with the systems described in the above patent applications and addresses problems that have been experienced during the research and development process.

The problem has been to devise a tamper evident seal for use with a drink packaging product which includes both a bottle and a drinking vessel. Early attempts to solve this problem have involved the use of a paper or plastic wrap fitted over the join between the mouth of the drinking vessel and the body of the bottle.

However this type of seal has a number of problems. It involves the use of an additional item of material, and this additional item must be fitted by adding another step to the production line used to fill and seal the drink packages. This additional material and production step adds to the cost of producing each packaged drink.

Also, a tamper evident seal which is removed from the packaged drink when the package is opened is a problem. The person opening the drink has one hand to hold the bottle and one to hold the drinking vessel, and another item can be a nuisance and is likely to become a litter hazard. This problem can be significant in an airline situation where seated passengers are provided with drinks, and where a tear off seal is yet another object to handle and one that will often end up on the floor or under seat cushions etc.

In New Zealand patent application number 538172 a tamper evident seal was developed which was situated within the drinking vessel and which engaged with the neck of the bottle. At present it is considered that the method of manufacture could be improved to reduce manufacturing costs.

The previous designs have incorporated tamper evident seals that are ideally formed from a plastics material having a useful degree of elasticity and memory. Plastics materials having these characteristics, and relatively low cost, are polypropylene and polyethylene. For this reason, a combined drinking vessel and cap that incorporates a tamper evident seal has had to be manufactured in at least two parts, or be manufactured entirely from polypropylene or polyethylene.

However, polypropylene or polyethylene are not the ideal choice for a drinking vessel when trying to manufacture a drinking vessel that is as "glass" like as possible. In such a case it is preferable to use a styrene plastics material which can be clear and a little more "glass" like in appearance and feel.

What is needed is a tamper evident seal design which does not require the use of a plastics material having a similar degree of elasticity and memory as that found in polypropylene or polyethylene materials. A tamper evident seal design that could be manufactured from a more rigid plastics material, for example a styrene plastics material, would facilitate the manufacture of a combined drinking vessel and cap from this material. This would allow the desirable characteristics of this material to be taken advantage of, while allowing greater opportunity to keep manufacturing costs low.

The use of a single plastics type for both the body of the drinking vessel and for the capΛase portion would also allow the use of ultrasonic welding if the drinking vessel is manufactured in two or more parts. The use of ultrasonic welding is desirable since it can improve the leak resistance of an assembled drinking vessel.

OBJECT

It is therefore an object of the present invention to provide a tamper evident seal design which will at least go some way towards overcoming the above mentioned problems, or at least provide the public with a useful choice. STATEMENTS OF THE INVENTION

Accordingly, in a first aspect, the invention may broadly be said to consist in a tamper evident seal for use in conjunction with a screw top container, comprising a ring which is frangibly linked to a cap, lid or closure device suitable for use with the container, wherein one or more protrusions extend inwardly from the ring and/or one or more recesses are provided about an inside diameter of the ring, the or each inwardly extending protrusion or recess being adapted to pass through or about a corresponding recess or recesses and/or protrusion or protrusions of a seal capturing feature on the neck of the container when the cap, lid or closure device is initially fitted onto the container.

Preferably the or each protrusion is shaped to facilitate entry into, or passage though, the recesses from one end of the recesses only, for example, the or each protrusion can have a bullet shaped nose portion adapted to guide the or each protrusion into or through the recesses in one direction only.

Preferably the or each protrusion is shaped to resist entry into, or passage through, the or each recess in the direction of relative motion of the or each protrusion when the cap, lid or closure device is being removed from the container.

Optionally the or each protrusion is shaped to interfere with passage through the or each recess in the direction of relative motion of the or each protrusion when the cap, lid or closure device is being removed from the container.

Optionally the or each protrusion is sized such that at least one dimension perpendicular to its direction of motion through the or each recess is a close tolerance or an interference fit with respect to the corresponding dimension of the or each recess.

Optionally the ring and the seal capturing feature both includes more than one protrusion and/or recess, or a combination of the two, and the spacing between adjacent protrusions and/or recesses on the ring is intentionally different to the corresponding recesses and/or protrusions on the seal capturing feature.

Preferably the ring and/or the seal capturing feature includes one or more saw tooth shaped features adapted to snag with features of the or each protrusion so as to interfere with the - A -

passage of the or each protrusion through the or each recess in the direction of relative motion of the or each protrusion when the cap, lid or closure device is being removed from the container.

Preferably the or each protrusion includes one or more saw tooth shaped features adapted to snag with features of the ring and/or the seal capturing feature so as to interfere with the passage of the or each protrusion through the or each recess in the direction of relative motion of the or each protrusion when the cap, lid or closure device is being removed from the container.

Preferably the frangible link includes a line of weakness between the ring and the cap, lid or closure device.

Preferably the screw top container is a bottle shaped container.

In a second aspect, the invention may broadly be said to consist in a cap, lid or closure device incorporating at least one tamper evident seal substantially as specified herein.

Preferably the closure device is also adapted for use as a drinking vessel.

Preferably the cap, Hd or drinking vessel is manufactured entirely, or primarily, from a styrene plastics material.

In a third aspect, the invention may broadly be said to consist in a container incorporating at least one cap, lid or closure device substantially as specified herein.

Preferably the container is substantially bottle shaped.

Preferably the closure device is also adapted for use as a drinking vessel.

Preferably the cap, lid or drinking vessel is manufactured entirely, or primarily, from a styrene plastics material.

The invention may also broadly be said to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of the parts, elements or features, and where specific integers are mentioned herein which have known equivalents, such equivalents are incorporated herein as if they were individually set forth.

DESCRIPTION

Further aspects of the present invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings in which:

FIGURE 1 is a cross sectional view of a cap incorporating a tamper evident seal of the present invention,

FIGURE 2 is a side elevation view of a container or bottle adapted for use with the tamper evident seal design of the present invention,

FIGURE 3 is a partially cutaway cross sectional view of a second example of a cap incorporating a tamper evident seal of the present invention,

FIGURE 4 is a partially cutaway side elevation view of a second example of a container or bottle adapted for use with the tamper evident seal design of the present invention,

FIGURE 5 is a partially cutaway cross sectional view of a third example of a cap incorporating a tamper evident seal of the present invention, and

FIGURE 6 is a partially cutaway side elevation view of a third example of a container or bottle adapted for use with the tamper evident seal design of the present invention.

With reference to Figures 1 and 2, a tamper evident seal (10) is shown having a ring (1 1) which is frangibly linked to a cap, lid or closure device (13), and one or more protrusions (15) which extend inwardly from the ring (1 1). The or each inwardly extending protrusion (15) is adapted to pass through a corresponding recess or recesses (17) in a seal capturing feature (19) on the neck (21) of the container (23) when the cap, lid or closure device (13) is initially fitted onto the container (23). The tamper evident seal (10) is primarily designed for use with a container (23) having a screw top (25) as shown in the drawings. The cap (13) is shown in a cross sectional view in figure 1, showing an internal thread (27) and one inwardly extending protrusion (15). A frangible link (29) joins the cap (13) to the ring (1 1). In this example the frangible link (29) is shown as a number of narrow links which bridge between the cap (13) to the ring (1 1) providing a line of weakness which can easily be broken to allow the cap (13) to be removed from the container (23) while leaving the ring (1 1) behind and retained about the neck of the container (23).

The ring (1 1) is retained about the neck of the container (23) by the seal capturing feature (19). The or each protrusion (15) is designed so that it will pass easily into or through the or each slot or recess (17) in one direction but not in the other direction. This can be achieved in a number of ways, and a few examples will be described herein. With reference to figures 1 and 2, the protrusion (15) is shown having an elongate shape, the length of which is generally aligned with the angle of the internal thread (27) of the cap (13), and having a bullet shaped nose end (31) and a "squared off tail end (33).

The width of the elongate shaped protrusion (15) can be very close to the width of the recess or slot (17) in the seal capturing feature (19), or be sized to provide an interference fit with the recess or slot (17) in the seal capturing feature (19). The bullet shaped nose end (31) allows the protrusion (15) to be guided into the recess (17) as the cap (13) is screwed onto the container (23). However, the squared off tail end (33) tends to prevent the protrusion (15) entering the recess (17) when the cap (13) is later unscrewed from the container (23) meaning that the ring (1 1) can be caught and retained by the seal capturing feature (19). Because of the shape of the protrusion (15) it can only exit back through the recess (17) if it is very closely aligned with it, and since the screw top (25) of the container and the internal thread (27) of the cap (13) are rarely precision threads, and will usually allow a degree of "backlash" or free play, it is very unlikely that the required alignment between the protrusion (15) and the recess (17) will occur.

The chance of alignment occurring between the protrusion (15) and the recess (17) when the cap (13) is removed can be reduced further by providing a number of mating protrusion (15) and recess (17) pairs about the ring (1 1) and the seal capturing feature (19) respectively, for example, corresponding saw tooth shaped features adapted to snag one another.

It is also possible to purposely misalign adjacent protrusion (15) or recess (17) to further reduce the possibility that all the protrusions (15) could exit through the recesses (17) when the cap (13) is removed. For example, if there are two recesses or slots (17) spaced evenly about the seal capturing feature (19), one hundred and eighty degrees apart, the protrusions could be spaced between one hundred and seventy five and one hundred and seventy nine degrees apart. The bullet shaped nose (31) and the elasticity of the protrusions (15), ring (11) and/or recesses (17) would allow the protrusions (15) to be guided into and through the recesses (17) as the cap (13) is screwed on, however, the slight misalignment of the protrusions (15) relative to the recesses (17) would make it very difficult for both of the protrusions (15) to re-enter the recesses (17) simultaneously to remove the ring (1 1) from the container (23).

Similarly, the width of the protrusions (15), that is the dimension perpendicular to their direction of motion through the recesses, can be very slightly larger than the width of the recesses (17), such that a slight interference is achieved. Again, the bullet shaped nose (31) and the elasticity of the protrusions (15), ring (1 1) and/or recesses (17) can allow the protrusions (15) to pass through the recesses (17) as the cap (13) is screwed on, and the interference fit combined with the squared off tail end (33) of the protrusions (15) would make it very difficult for the protrusions (15) to re-enter the recesses (17) to remove the ring (1 1) from the container (23).

Figures 3 and 4 show a further variation on this theme. In this example the protrusions (15) themselves are provided with "saw tooth" shaped protrusions (35), and the recesses (17) are similarly provided with "saw tooth" shaped edges (37). The "saw tooth" shaped protrusions (35), and the "saw tooth" shaped edges (37), are aligned such that the protrusions (15) can pass easily into, or through the recesses (17) when the cap (13) is screwed onto the container (23). However, the "saw tooth" shaped protrusions (35), and the "saw tooth" shaped edges (37), are also aligned to resist re-entry, or the passage of, the protrusions (15) through, the recesses (17) in the direction of motion of the protrusions (15) when the cap (13) is being removed from the container (23). The "saw tooth" shaped protrusions (35), and the "saw tooth" shaped edges (37) are aligned such that they interfere with the passage of the protrusions (15) through the recesses (17) when the cap (13) is being removed.

Figures 5 and 6 show yet another variation on the concept. In these two figures the aft face (39) of the protrusions (15) is concave and the underside of the seal capturing feature (19) is provided with one or more notches or protrusions (41). The notches or protrusions (41) can catch the aft face (39) of the protrusions (15) when the cap (13) is removed from the container (23) causing the tamper evident ring (1 1) to shear away from the cap (13).

An advantage of the tamper evident seal (10) is that it is designed to engage with, or be j captured by, the seal capturing feature (19) without having to expand over it, or to shrink back to its original size after expansion. For this reason, the tamper evident seal (10), and some or all of the cap, lid or closure device (13) of which it is a part, can be manufactured of a plastics material that does not have particularly useful elasticity or memory characteristics, for example a more rigid plastics material such as styrene. This allows other favourable characteristics of a more rigid plastics material to be exploited, for example the more "glass" like look and feel that a styrene plastics material can provide.

The applicant has experimented with the addition of varying amounts of plasticisers in styrene plastics, but has found that even when styrene is provided with greater flexibility it does not have a useful degree of memory. And for this reason, they were unable to create a reliable tamper evident seal of the type that expand when fitted and shrink to allow capture, using styrene plastics and plasticisers.

VARIATIONS

Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof.

In the examples described herein, the protrusions (15) are part of the ring (1 1), and the recesses or slots (17) are part of the container (23). In an alternative embodiment, the protrusions (15) can be part of the container (23), and the recesses or slots (17) can be part of the ring (1 1). Or a combination of the two embodiments could be employed. Clearly an important feature of the invention is the relative movement of a protrusion through a recess or slot, and the protrusion(s) can be on either the ring (11) or on the container (23).

In the above examples, the seal capturing feature (19) is shown as a ridge which extends about the neck (21) of the container, and which has slots or recesses (17) positioned about its periphery. However, it is envisaged that the slots or recesses (17), or protrusions, could simply be formed in the neck (17) of the container (23) to form the seal capturing feature (19).

Also, in the above examples the container (23) is shown as a bottle shaped container, however it is envisaged that the tamper evident seal (10) could be used on a range of packaging products or. containers of other shapes, for example on the lid of a jar shaped container.

Also, in the above examples the tamper evident seal (10) is shown as part of a cap, however the tamper evident seal (10) could also be part of a lid or other closure device. An example of another closure device is a drinking vessel of the type described in New Zealand patent application numbers 527195, 538172 and 551470, that is, a drinking vessel that also incorporates the features of a bottle cap.

Similarly, the closure device could be a cap that is adapted to also function as a measuring device, for example, a measuring cap for use with a medicine bottle.

DEFINITIONS

Throughout this specification the word "comprise" and variations of that word, such as "comprises" and "comprising", are not intended to exclude other additives, components, integers or steps.

ADVANTAGES

Thus it can be seen that at least the preferred form of the invention provides a tamper evident seal which can be made of a relatively rigid plastics material allowing greater manufacturing flexibility which is particularly useful in the manufacture of combined drinking vessel and caps for a drinks container.

Claims

1. A tamper evident seal for use in conjunction with a screw top container, comprising a ring which is frangibly linked to a cap, lid or closure device suitable for use with the container, wherein one or more protrusions extend inwardly from the ring and/or one or more recesses are provided about an inside diameter of the ring, the or each inwardly extending protrusion or recess being adapted to pass through or about a corresponding recess or recesses and/or protrusion or protrusions of a seal capturing feature on the neck of the container when the cap, lid or closure device is initially fitted onto the container.

2. A tamper evident seal as claimed in claim 1, wherein the or each protrusion is shaped to facilitate entry into, or passage though, the recesses from one end of the recesses only.

3. A tamper evident seal as claimed in any one of claims 1 or 2, wherein the or each protrusion is shaped to resist entry into, or passage through, the or each recess in the direction of relative motion of the or each protrusion when the cap, lid or closure device is being removed from the container.

4. A tamper evident seal as claimed in any one of claims 1 to 3, wherein the or each protrusion is shaped to interfere with passage through the or each recess in the direction of relative motion of the or each protrusion when the cap, lid or closure device is being removed from the container.

5. A tamper evident seal as claimed in any one of claims 1 to 4, wherein the or each protrusion is sized such that at least one dimension perpendicular to its direction of motion through the or each recess is a close tolerance or an interference fit with respect to the corresponding dimension of the or each recess.

6. A tamper evident seal as claimed in any one of claims 1 to 5, wherein the ring and the seal capturing feature both includes more than one protrusion and/or recess, or a combination of the two, and the spacing between adjacent protrusions and/or . recesses on the ring is intentionally different to the corresponding recesses and/or protrusions on the seal capturing feature.

7. A tamper evident seal as claimed in any one of claims 1 to 6, wherein the ring and/or the seal capturing feature includes one or more saw tooth shaped features adapted to snag with features of the or each protrusion so as to interfere with the passage of the or each protrusion through the or each recess in the direction of relative motion of the or each protrusion when the cap, lid or closure device is being removed from the container.

8. A tamper evident seal as claimed in any one of claims 1 to 7, wherein the or each protrusion includes one or more saw tooth shaped features adapted to snag with features of the ring and/or the seal capturing feature so as to interfere with the passage of the or each protrusion through the or each recess in the direction of relative motion of the or each protrusion when the cap, lid or closure device is being removed from the container.

9. A tamper evident seal as claimed in any one of claims 1 to 8, wherein the frangible link includes a line of weakness between the ring and the cap, lid or closure device.

10. A cap, lid or closure device incorporating at least one tamper evident seal substantially as claimed herein.

1 1. A cap, lid or closure device as claimed in claim 10, wherein the closure device is also adapted for use as a drinking vessel.

12. A cap, lid or closure device as claimed in any one of claims 10 or 1 1, wherein the cap, lid or drinking vessel is manufactured entirely, or primarily, from a styrene plastics material.

13. A container incorporating at least one cap, lid or closure device substantially as claimed herein.

14. A container as claimed in claim 13, wherein the container is substantially bottle shaped.

15. A container as claimed in any one of claims 13 or 14, wherein the cap, lid or drinking vessel is manufactured entirely, or primarily, from a styrene plastics material.