GB2397295A

GB2397295A - Tamper evident closure with translucent window

Info

Publication number: GB2397295A
Application number: GB0226143A
Authority: GB
Inventors: Simon George Calverley; Bryan James Christophersen; Roland Isherwood; James Ovenstone
Original assignee: De la Rue International Ltd
Current assignee: De la Rue International Ltd
Priority date: 2002-11-08
Filing date: 2002-11-08
Publication date: 2004-07-21
Also published as: GB0226143D0

Abstract

A tamper evident closure comprises a pair of relatively movable members (outer and inner caps) and an intermediate light valve (rough prismatic surface). When the inner and outer caps are in a first relative position, indicia are visible through the light valve and when the caps are in a second relative position, the indicia are not visible. The indicia may include text, a design, logo or any other recognisable graphical information. The outer cap may be provided with a translucent window on the top surface and on to the back surface a translucent polymeric material may be provided.

Description

1 2397295

TAMPER EVIDENT CLOSURE

The current invention relates to closures such as those used on bottles and the like. In particular the invention relates to providing evidence that a closure device has been utilised previously or has been tampered with in some way.

Many brand owners face serious issues due to counterfeiting of goods. In some cases such as the food and pharmaceutical industry these problems extend beyond loss of revenue and into health and safety issues. Fake goods are generally not of the same quality or subject to the same stringent health and safety guidelines that are imposed on the brand owners. Consequently the consumer needs to be confident that the goods they are buying are genuine and safe to consume or use. Therefore there is increasing pressure on the brand owners to provide quick and easy means of indicating that goods are both genuine and have not been tampered with prior to sale.

Tampering of goods can take on a number of forms. Within the drinks industry one common form of tampering is the refilling of genuine containers with cheaper brands or counterfeits. The consumer assumes they are buying the real goods because the packaging is real but later find the goods to be substandard. The brand owners are therefore keen to firstly try and prevent the act of refilling and secondly to make it obvious whether a bottle or container has been refilled.

It is known to provide bottle caps and other closures with tamper evident devices. It is known to provide bottles with shrink sleeves, which must be removed in order to access the contents on the container. For additional security it is known to provide shrink sleeves with holographic elements. In an another example in many countries around the world alcoholic drinks and tobacco products are provided with tax stamps to indicate duty has been paid. In the majority of cases these tax stamps are applied to the packing in such away that opening the pack irrevocably damages the tax stamp.

More complex constructions are also known to form part of a closure it self. For example bottle tops may be provided with valves or other devices to try and prevent refilling of a product. In many cases a cap is connected to a collar by means of frangible links. When the cap is removed the links are broken and the collar remains attached to the packaging.

The current invention seeks to provide a closure with overt visible evidence that a container has been previously opened or tampered with in some way. The inventors have recognised that the ability to overtly display that a closure has been tampered with is of key importance.

The invention will now be described with reference to the following figures.

Figures 1A and 1B show a first embodiment of the current invention in both unopened and opened condition.

Figures 2A and 2B show a second embodiment of the current invention in both unopened and opened condition.

Figures 3A and 3B show a third embodiment of the current invention in both unopened and opened condition.

Figures 4A and 4B show a fourth embodiment of the current invention in both unopened and opened condition.

Figures 5A and 5B show a fifth embodiment of the current invention in both unopened and opened condition.

As stated above the current invention is concerned with providing the consumer or user of a product a visible indication that the container has or hasn't been opened or tampered. To achieve this the current invention allows indicia to be revealed or obscured when a closure device is utilised. .

Figures 1A and 1B illustrate, schematically, a first embodiment of the current invention. Here a bottle cap is constructed in two portions, an inner cap and an outer cap. Onto the top surface of the inner cap indicia are provide typically by printing. The indicia may comprise text, a design, logo or any recognizable graphical information. The outer cap is provided with a transparent window on the top surface and on to the back of this top surface is provide a translucent polymeric material, for example a silicone polymer. The transparent polymeric material has a prismatic rough surface cut into it on the side facing the printed information on the inner cap. In the figure this translucent polymeric material is referred to as an elastomeric light valve.

When the cap is at rest, as shown in figure 1A, there is an air gap between the printed information and the light valve. As the light valve has a very different refractive index to air light passing through is deflected away from the viewer and the message cannot be seen. However if the light valve is pushed into contact with the printed information, as shown in figure 1B, the air gap is removed and light is not deflected from the viewer and as a result the message becomes viewable.

Once the pressure is released the cap returns to its s original position and the printed information can no longer be read. In this example the prime function of the cap is to provide evidence to the user that the cap is authentic and that the goods within the container are genuine.

The cap may also be modified so that the process is non- reversible so that once pressure has been applied the cap locks into place making the printed information permanently visible. This variation would make the cap tamper evident as providing a proof of authenticity.

In a second embodiment the user need not apply a down ward pressure to view the information. In this example the message and the light valve are brought into contact as a result of a twisting action. In this instance information appears on the side of the closure device.

Prior to the cap being twisted the two translucent polymeric material sections are in contact and pressed together. As they are in compression the indicia printed on the inside of the inner cap are readable, as shown in figure 2A. After the cap has been twisted the two polymers are no longer in contact and thus an air gap is formed so the message can no longer be read. Once out of compression the two polymer layers expand beyond each other and consequently cannot be returned to their original position. In this instance as the indicia can only be read prior to opening the prime function of this embodiment is as a tamper evident feature.

Figures 3A and 3B show an alternative version of the embodiment shown in figures 2A and 2B. Here the message is not apparent until after the cap has been twisted. In this instance one of the polymeric layers is formed in the shape of a wedge. As the two polymeric materials are twisted together the wedge shaped leading edge allows the materials to overlap and be brought into intimate contact. Once in intimate contact the indicia are revealed. In a preferred variant the inner and outer cap should then be locked in place so that the two polymeric materials cannot be moved apart again and the revealed message become permanent. This may be achieved by a simple locking mechanism, as shown, or by another means.

Figures 4A and 4B show an enhancement of the third embodiment where different images are visible dependent upon whether or not the cap has been opened. Here two sets of printed indicia are provided on the inner cap along with their associated regions of translucent polymeric material. The outer cap has a single wedge shaped region of translucent polymeric material which when unopened is in intimate contact with the first region of polymeric material on the inner cap. Twisting the cap then brings the polymeric material on the outer cap into intimate contact with the second region of polymeric material on the inner cap to display the second set of indicia. In this instance the mechanism is made non-reversible by providing polymeric materials with a suitably high expansion coefficient. The first region of polymeric material on the inner cap expands so such an extent that the material on the outer cap is unable to brought back into intimate contact.

Figures 5A and 5B show one further embodiment of the current invention. Again a twisting action is used to bring the two regions of translucent polymeric material into contact, but in this instance the indicia are displayed on the top of the cap. Essentially the same mechanism is used as described for the second third and fourth embodiments with two regions of translucent polymeric material offset from each other. In this instance the polymeric material is displaced on the top of the inner cap and underneath the top of the outer cap.

When the cap is twisted the two regions are brought into intimate contact and the indicia are displayed.

In all the above embodiments can be provided with additional features that can further enhance the security of the device. For example providing both visible and invisible printed information. The invisible printed information would only be made viewable by use of a suitable excitation source such as W or IR. The inclusion of invisible print would increase the security and add an additional means for authentication. Other potential improvements include the use of coloured dyes in the polymeric layer to act as filters in combination with metameric print features.

The printed information provided may also be machine readable, for example a barcode. The barcode may contain information relating to the product itself such as its point of origin, distribution chain and intended destination. Such machine-readable information may be visible or invisible. If it is invisible it may be printed on top of visible information intended for public use.

Claims

1. A tamper evident closure comprising a pair of relatively movable members and an intermediate light valve wherein when the members are in a first relative position, indicia are visible through the light valve, and when the members are in a second relative position, the indicia are not visible.