WO1999024329A1

WO1999024329A1 - Tamper evident closure

Info

Publication number: WO1999024329A1
Application number: PCT/GB1998/003350
Authority: WO
Inventors: William Frank Tyldesley
Original assignee: Cambridge Consultants Limited
Priority date: 1997-11-10
Filing date: 1998-11-10
Publication date: 1999-05-20

Abstract

The present invention concerns a tamper-evident closure means (10) which comprises a sealed reservoir means (4) containing a colouring means, a transfer means (5), a window means (9) and a rupturing means (8), whereby, upon opening of the tamper-evident closure means, the rupturing means ruptures the sealed reservoir means and the colouring means flows via the transfer means to the window means thus indicating tampering to a user.

Description

Tamper Evident Closure

Technical field of the invention

The present invention relates to a packaging development which indicates whether a packaging means has been opened. In particular, the present invention relates to a closure means which, on opening, changes the colour of a window in the closure means, producing a colour change.

Background Art

Pilferproof and childproof closures are known in the art. Probably the most common variety are the several different 'push and twist' closures which are available in the marketplace. The

ClicLoc™ system is believed to be the most widely known example in the UK/European market. Once opened, such known closures can be replaced onto a container without any indication that they have been opened. WO-A-93/04941 discloses an example of such a known pilferproof closure.

Tamper-evident closures are also known in the art. The most common form of tamper-evident closure involves the breaking of a frangible component of the closure such as a tear-off band as in EP-A-0 726 208. Such tamper-evident closures may often be

'avoided' if desired by careful opening of the closure. Also, after opening all traces of the tear-off band may be and often is removed. Thus, unless a user knew that there was originally a tear-off band on the closure means, they would not instantly recognise whether tampering had occurred or not.

Another type of tamper-evident closure known in the art uses a change in colour of a part of the closure to indicate tampering. These known closures may either exploit mechanical mechanisms in the colour changing system or they may use a chemical agent which reacts either with air or with another chemical agent upon opening of the closure means. Examples of the chemical reagent- type closure are given in US-A-4 986 429, US-A-5 581 978, EP-A-0 538 410.

Prior art mechanical colour-indicating systems are often easy to override and thus it is often easy to reset the tamper evidency.

Whilst the prior art chemical reagent systems have an advantage over the mechanical systems in that they may be made more difficult to reset, these prior art systems suffer from disadvantages including:

-Many such systems require the use of specialised reagents which react in some way in order to turn coloured and thus give an indication of tampering. This reaction may be caused in various different ways such as contact with air or reaction with pressure, or through having two membranes coated with different reagents which, upon the removal of one membrane from the other, undergo a colour change or even, in one example, the use of an LCD reagent. These specialised reagents necessarily increase the expense of such a closure. The use of such specialised reagents also means that great care needs to be taken when assembling the closure - i.e. ensuring that no air contact occurs etc.

-Many such systems use 'microcapsules' of reagent which burst upon closure opening. The construction of such 'microcapsules' adds to the expense of such a closure and makes the assembly of the closure a delicate operation.

The present invention aims to provide an alternative form of tamper-evident closure.

The present invention aims to overcome the disadvantages associated with prior art tamper-evident closures . It is the aim of the present invention to provide a tamper-evident closure means of simple and cheap construction which is difficult to reset. It is a further aim of the present invention to provide the advantages of a childproof closure means with those of a tamper- evident closure means.

Summary of the Invention

The present invention concerns a tamper-evident closure means which comprises a sealed reservoir means containing a colouring means, a transfer means, a window means and a rupturing means, whereby, upon opening of the tamper-evident closure means, the rupturing means ruptures the sealed reservoir means and the colouring means flows via the transfer means to the window means thus indicating tampering to a user.

The present invention provides an alternative type of tamper- evident closure.

The closure of the present invention is very difficult to reset and/or avoid.

The closure of the present invention is also simple and inexpensive to produce - not having the complex mechanics of mechanical colour change indicators nor either the need for specialist chemicals or 'microcapsules' of prior art chemical colour change indicators .

The present invention allows the use of a standard dye in indicating tampering - no longer is there any need for expensive specialised reagents (although clearly these could be used if desired) .

The present invention also avoids the need for specialised, expensive 'microcapsule' structures or the like since the dye may be stored initially out of view and only subsequent to the opening of the closure does the dye flow to an area where it may be seen by a user.

Further aspects, advantages and objectives of the invention will become apparent from a consideration of the drawings and the ensuing description.

List of Drawings

Figure 1 A diagram depicting the parts required for an embodiment of the invention; Figure 2 A diagram depicting the parts of figure 1 assembled and showing the action of the present invention; Figure 3 An exploded isometric view of the parts of figure 1.

Detailed description of the invention

The invention will now be disclosed in the form of a particular embodiment involving a closure system for packs that has an inbuilt annular reservoir with the aid of figures 1 and 2.

Figure 1 shows the parts which make up the closure means of the embodiment. The closure means are used to close a package (1) , such as a medicine bottle which has a threaded neck (2) for receiving the closure means (10) .

The closure means (10) consists principally of two parts - a first, inner part (3) and a second, outer part (7) .

The inner part (3) has an annular reservoir (4) which contains a coloured dye. The reservoir (4) is sealed by a foil covering (5) or the like which is superposed by a layer of absorbent material such as blotting paper or the like. Thus the foil/absorbent material fulfils the dual function of a seal and a transfer means for transferring the coloured dye from the reservoir (4) to a place where the user may see it upon operation.

The outer part (7) has sharpened portions (8) for rupturing the seal/transfer means (5) of the inner part (3) upon operation. The outer part also has an opening (9) through which the seal/transfer means may be seen by a user.

A lens (6) may be provided to cover the piece of absorbent material (9) and to make it easier to see.

Figure 2 shows an assembled closure means (10) according to this embodiment. Some means of preventing the closure means being accidentally depressed may be provided - shown schematically as a removable band (11) .

In its untampered' state (12) , the closure means sits on the neck of the pack 1 and the dye in the reservoir (4) is sealed in by the seal/transfer means (5) .

Upon pushing the closure means, the sharpened portions (8) of the outer part (7) rupture the seal/transfer means (5) and the dye in the reservoir is sucked up by the absorbent transfer means (5) which thus, more or less instantaneously changes colour - thus indicating to a user looking at the window (9) that tampering has occurred.

Opening of the closure (10) forces a rupturing of the lidding (5) of the reservoir (4) . This is caused by a sharpened ring (8) on the inside of the outer cap (7) being forced down through the reservoir lidding material (5) .

The mechanical action to force the break through may be facilitated by the down push force used typically to open 'push and twist' type (i.e. ClicLoc-style) closures - as shown schematically by the extrusions (15) on the inner part (3) in figure 3, although many other possibilities exist which a person skilled in the art would arrive at without the use of any inventive skill. Such alternatives include arranging the closure means so that a screw mechanism is involved to rupture the reservoir or using the squeezing action of a 'squeeze and turn' type closure etc. The screw mechanism approach may be more appropriate in an FMCG or a security use.

Wicking material on the foil lid (5) is then pushed down into the fluid reservoir (4), which allows the fluid to visibly spread across the window (9) of the outer cap (7) .

The fluid release can happen onto a simple substrate as illustrated, or into a more complex labyrinth. The fluid used may be designed to permanently mark the inside of the cap.

The process of releasing a fluid agent into the closure to reveal evidence of opening could be exploited for promotional purposes. Since the principal of operation relies on the release of a hidden dye a proportion of closures could be made with a different colour option for winning packs.

The promotional pack could be made to reveal a colour change message either by print -that is revealed by changing colour contrast, or print that is made visible by chemical action.

In this way, high-value products could be given an anti- tampering closure using this concept.

A paper-based wick may be used or, if desired a more sophisticated laminate may be used to produce interference effects etc. This could be combined with a lens design that accentuates the effect.

The invention is appropriate for use in, for example, the healthcare market as a security device for pharmaceutical packaging or for promotional products in the FMCG market.

Claims

1. A tamper-evident closure means (10) comprising:

- sealed reservoir means (4, 5) containing a colouring means ;

- rupturing means (8) for rupturing the sealed reservoir means (4, 5) upon opening of the closure means (10);

- window means (6, 9) viewable by a user to see whether tampering has occurred; and - transfer means (5) for transferring the colouring means from the sealed reservoir means (4, 5) to the window means (6, 9) whereby, upon opening of the tamper-evident closure means (10), the rupturing means (8) ruptures the sealed reservoir means (4, 5) and the colouring means flows via the transfer means (5) to the window means (9) thus indicating tampering to a user.

2. A tamper-evident closure means (10) according to claim 1 wherein said transfer means (5) transfers the colouring means by capillary action.

3. A tamper-evident closure means (10) according to claim 2 wherein said transfer means (5) consists of a piece of absorbent material such as blotting paper.

4. A tamper-evident closure means (10) according to any of the preceding claims which further comprises means for rendering the tamper-evident closure means (10) pilferproof wherein an additional action required to overcome the pilferproof nature of the tamper-evident closure means (10) is used to give the force required to rupture the sealed reservoir means (4, 5) .

5. A tamper-evident closure means (10) according to any of the preceding claims which further comprises lens means (6) for rendering the window means (9) better visible to a user.

6. A method for indicating tampering with a closure means comprising the steps of:

- providing a sealed reservoir means (4, 5) containing colouring means;

- causing the reservoir means (4, 5) to rupture upon opening of the closure means (10) ; and - upon rupture of the reservoir means (4, 5), causing the colouring means contained in the reservoir means to flow via a transfer means (5) to an area (9) which is visible to a user.