GB2306160A

GB2306160A - A tamper-evident container

Info

Publication number: GB2306160A
Application number: GB9520841A
Authority: GB
Inventors: Daryl John Thompson
Original assignee: PENLEA PLASTICS Ltd
Current assignee: PENLEA PLASTICS Ltd
Priority date: 1995-10-11
Filing date: 1995-10-11
Publication date: 1997-04-30
Also published as: GB9520841D0

Abstract

A tamper-evident container comprises a base 14, a lid 10 with a pull-tab 13 located at an outer edge, and means for indicating whether the pull-tab has been used. The indicating means may be one or more lines of weakness 17 extending inwardly from the pull-tab. Alternatively, the indicating means may be a tearable label (not shown) overlying the pull-tab or the whole lid surface. The lid may have a peripheral flange 12 which is retained by an undercut channel 16 on the container base. The pull-tab may extend outwardly beyond the rim 15 of the base. The container may be made from a plastics material e.g. polypropylene.

Description

Tamper-evident Container The present invention is a container, for example for perishable goods, devised to provide clearly visible evidence of any attempt to gain access to its contents.

So-called "tamper-proof" packs are well known and usually are designed not so much to prevent tampering, which is almost impossible to achieve, but rather to give some indication of when tampering has taken place. Although available such packs may show some sign of tampering of the casual and unsubtle variety, for example when a lid has been partly or fully pulled open in the intended manner of use of the pack, the signs may be absent or not readily apparent when the tampering is more subtly carried out, for example in a more calculated manner as by a slight levering or lifting of the lid. However tampering of this latter type may be no less harmful to the contents of the pack and it is therefore important to be able to identify such tampering readily, without having to subject the pack to careful examination.

It is an object of the present invention to provide an improved form of container, which is less vulnerable to undetected tampering than are many prior forms of n "tamper-proof" containers.

The container according to the present invention comprises a base part, a lid having a tag located at the circumference of the lid, the lid being removable without difficulty only by use of the tag, and indicator means which is damaged when the tag is used to remove the lid.

Thus when the indicator means has been found to be damaged, this is a clear sign that the tag has been used and that tampering has occurred.

In the case of the container according to the invention, -usually the contents, for example food or other perishable goods, are located in the container base and the lid itself if generally flat. However it should be understood that the invention is equally applicable to packs, for example transparent packs for the display of cakes or the like, wherein the base is generally flat and the lid is deeply shaped to cover or contain the contents of the pack.

The lid of the container according to the invention is difficult, or even impossible, to remove without the assistance afforded by the tag. One preferred way in which this result may be achieved is to provide a re-entrant or undercut channel or groove around at least a major part of the circumference of the container base and to provide on the lid a peripheral flange adapted to enter that channel or groove and to be retained within it. When the lid is fitted in this way, it may be very difficult or impossible for the lid to be pulled upwardly away from the container, because gaining an adequate grip on the lid may be very difficult, except by means of the tag.

The tag is located at the circumference of the lid and most conveniently takes the form of a lateral extension from the perimeter of the lid. In the case where the lid includes a peripheral flange to engage a channel or groove in the container body, the tag is preferably a lateral extension from the flange. The shape of the tag is a matter of choice and convenience but it preferably extends beyond the outer rim of the container base.

The container base preferably has a continuously-curved circumference when viewed in plan. For example, it may be generally rectangular (including square) with radiused "corners" . However it is strongly preferred that the container base be generally circular or elliptical in plan, and that the lid be of the same shape.

The container base and the lid, which may be of the same or different materials, may be of any material which is conventionally used for containers of this general type, especially of synthetic polymeric materials. Such materials include, but are not limited to, polyvinyl chloride, polythene, polypropylene (which is of particular value for microwavable products) and polystyrene.

An important characteristic feature of the tamper-evident container according to the present invention is the indicator means which is damaged when the tag is used to remove the lid. In one form of the invention, by the use of the tag the lid itself is damaged. For example, one or more lines of weakening such as perforations may be provided inwardly of the circumferential tag, such that when the tag is lifted to remove the lid, the lid is first torn before the tag can pull the lid.

In another form of the invention, the indicator means comprises a tearable label, adhered to the container and the lid and overlying the tag, such that lifting of the tag tears the label before the lid itself can be lifted. One or more lines of weakening may be provided in the label to ensure the damage caused to the label by the lifting of the tag is clearly evident.

If desired, a tearable label of this type may be used in combination with a lid which itself is designed to be damaged by use of the tag to lift the lid. Either or both of the label and tag may then be provided with one or more lines of weakening.

When the indicator means comprises a tearable label, the label may cover the whole of the surface of the lid, extending also to be adhered to the container, or may cover only a more limited area of the lid, for example only that area which overlies the tag.

The invention will now be further described with reference to the accompanying drawings, which illustrate, by way of example only, one preferred embodiment of the tamper-evident container according to the present invention and wherein Fig.l is a plan view of the container lid; Fig.2 is a sectional view of the lid shown in Fig.1; and Fig3 is a view in cross-section of the container base with the lid of Figs.l and 2 fitted to seal the container.

The illustrated lid 10 is generally circular in plan with a downwardly-curved peripheral side 11 from which a short flange 12 extends radially outwardly. A tag 13, formed integral with the lid 10, extends from the flange 12. Tear-lines 17 may be provided in the lid as an optional feature.

The container base 14 has an upstanding peripheral rim 15 shaped to provide an under-cut channel 16 around the whole of the circumference of the container base except for a short length shaped to receive the tag 13. When the container base 14 and the lid 10 are assembled together as illustrated in Fig.3, the flange 12 projects into the under-cut channel 16 and retains the lid securely in position. Because there is no ready access to the edge of the lid except at the position from where the tag 13 projects, it is extremely difficult to remove the lid except by lifting the tag.

When the optional tear-lines 17 are provided, lifting of the tag 13 first tears the lid 10 along the lines 17 before the tag is able to remove the lid from the container base 14.

Thus any illicit attempt to remove the lid leaves clear evidence of tampering in the form of the torn tear-lines 17.

Instead of, or in addition to, the tearlines 17, a label (not shown) may be adhered across at least a part of the peripheral line of engagement of the lid 10 and base 14, including at least that area which includes the tag 13.

Thus lifting of the tag tears the label before the lid can itself be lifted. The tearing of the lid is then clear evidence of tampering.

Tearing of the label may itself be assisted and indicated by tear-lines.

Claims

1. A tamper-evident container comprising a base part, a lid having a tag located at the circumference of the lid, the lid being removable without difficulty only by use of the tag, and indicator means which is damaged when the tag is used to remove the lid.

2. A tamper-evident container as claimed in Claim 1, wherein the lid is generally flat.

3. A tamper-evident container as claimed in either of the preceding claims, having a re-entrant or undercut channel or groove around at least a major part of the base and, on the lid, a peripheral flange adapted for retention within the channel or groove.

4. A tamper-evident container as claimed in any of the preceding claims, wherein the tag is a lateral extension from the perimeter of the lid.

5. A tamper-evident container as claimed in any of the preceding claims, wherein the tag extends beyond the outer rim of the container base.

6. A tamper-evident container as claimed in any of the preceding claims, wherein the container base has a continuously-curved circumference in plan view.

7. A tamper-evident container as claimed in Claim 6, wherein the base is generally circular or elliptical in plan.

8. A tamper-evident container as claimed in any of the preceding claims, wherein the base and lid are each of a synthetic polymeric material.

9. A tamper-evident container as claimed in Claim 8, wherein the synthetic polymeric material is polyvinyl chloride, polythene, polypropylene or polystyrene.

10. A tamper-evident container as claimed in any of the preceding claims, wherein the indicator means comprises one or more lines of weakening in the lid inwardly of the tag.

11. A tamper-evident container as claimed in any of the preceding claims, wherein the indicator means comprises a tearable label, adhered to the container and to the lid and overlying the tag.

12. A tamper-evident container as claimed in Claim 11, wherein the label has one or more lines of weakening.

13. A tamper-evident container as claimed in Claim 11 or Claim 12, wherein the tearable label covers the whole of the surface of the lid.

14. A tamper-evident container substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.