EP0900743A2

EP0900743A2 - A tamper-evident lid

Info

Publication number: EP0900743A2
Application number: EP98306163A
Authority: EP
Inventors: Nikee Webb
Original assignee: Polarcup Ltd
Current assignee: Huhtamaki UK Ltd
Priority date: 1997-09-04
Filing date: 1998-08-03
Publication date: 1999-03-10
Also published as: EP0900743A3; GB9718849D0

Abstract

A tamper-evident lid for a container, the lid comprising a sheet defining a body of the lid, engagement means for engaging the lid with the container and locking means, connected to the body by a web. The locking means is moveable about the web from a first position in which the container is engaged to a second position in which the container is not engaged and in which the locking means is caused to move from the first position to the second position before the engagement means is disengaged from the container.

Description

The present invention relates to a lid for a container. More particularly, it relates to a lid that, when in place on a container, provides an indication as to whether it has been previously removed from the container and therefore whether the contents of the container may have been exposed to the outside environment, whether additional contents may have been introduced into the container or whether the contents have otherwise been tampered with. These lids are commonly referred to as "tamper-evident" lids.
Tamper-evident lids are used in a wide variety of fields. This type of lid can be used in conjunction with various containers for the storage of, for example, pharmaceuticals and other chemicals, foodstuffs, paints and varnishes and other items such as medical or surgical instruments. However, the lid of the present invention is particularly suitable for use in conjunction with a container for foodstuffs. Most particularly it is suitable for use with containers for foodstuffs such as butter and other spreads and ice cream.
Conventional lids for containers can be formed from any suitable material. For example, these lids may be formed from a metal foil or from a plastics material. Lids formed from a metal foil are single-use lids as, once removed, they cannot be replaced on the container. The use of plastics material is advantageous as it can be readily formed into complex shapes which enables fastenings to be included such that the lid can be removed from the container and then replaced. Further, plastics material will not contaminate the foodstuffs or other contents of the containers.
In some circumstances, both types of lid can be used in combination such that a lower foil lid preserves the contents of the container and a plastics lid which can be used once the foil has been removed as a removable cover during ongoing use.
Lids formed from a plastics material also have certain disadvantages and drawbacks. For example, in some cases, once the lid has been replaced, it can not be readily determined whether the container has already been opened. In addition, repeated removal and replacement of the lid can lead to damage to the lid. Once the lid becomes cracked or damaged, even when the lid is in place, the contents in the container can be exposed to the outside environment and therefore they may become contaminated.
Many attempts have been made to overcome these disadvantages. One solution proposed is the use of a strip of material that is integral with the lid. This strip must be removed, generally by tearing along a perforation, before the lid can be removed from the container. These strips are generally referred to as tear-strips and an example of the use of a tear-strip is described in US 4790448. However, these strips are often made from a resilient plastics material and their removal may be difficult. This is particularly the case if the user has reduced dexterity.
Another example of a tamper-evident lid is one that incorporates a flange that may be integral with the lid, the container or with both the lid and the container or may be a separate item. In order to remove the lid from the container, the flange must either be totally removed, or it must be broken. Flanges of this type can be made from a metal foil, a plastics material, paper or any other suitable material and examples of their use are described in AU 72719/91, US 5573134 and GB 2307902. However, flanges of this type may become accidentally broken during either storage or transit of the filled container, and thus it may erroneously appear that the container has been opened.
It is therefore desirable to provide a tamper-evident lid which can be readily opened but which is resistant to damage during storage or transit of the container.
We have now discovered that these drawbacks may be overcome by providing a lid which comprises a part that may be moved relative to the remaining parts of the body of the lid in a hinge-type manner. Once this part has been moved, it will be clear that movement has occurred. Further, the remaining parts of the lid will then be readily removed from the container.
Thus, according to the present invention, there is provided a tamper-evident lid for a container, said lid comprising a sheet defining a body of the lid, engagement means for engaging the lid with the container and a locking means connected to the body by a web wherein the locking means is movable about the web from a first position in which the container is engaged to a second position in which the container is not engaged and wherein the locking means may be caused to move from the first position to the second position before the engagement means may be disengaged from the container.
It will be understood that the lid may be readily replaced on the container by reversing these steps. Thus, the engagement means are engaged with the container and the locking means is then moved from the second position to the first position to lock the lid in place.
The locking means preferably rotates relative to the body of the lid and around an axis defined by the web. In a particularly preferred embodiment, the movement of the locking means will describe an arcuate path finishing at a position above the plane of the body. In view of the nature of the movement required, it is unlikely that the movement from the first to the second position may occur accidentally during storage or transit of the container. In the event that movement of part of the lid were to occur it would be apparent by a simple visual inspection of the container.
In a particularly preferred embodiment, at least two frangible flanges will extend between the engagement means and the locking means co-axially with the flexible web which when the locking means is first moved to the second position will break making it particularly clear that the locking means has been moved.
It is desirable to minimise any damage to the lid during the repeated removal and replacement of the lid on the container.
Accordingly, as a preferred feature of the present invention there is provided a tamper-evident lid for a container that is removed by sliding the lid from the rim of the container. Thus, once the locking means has been released, the body of the lid is moved laterally relative to the container such that the engagement means are disengaged. Usually, the lateral movement will be horizontal movement away from the point at which the locking means is situated. In this arrangement, the locking means will generally extend across the width of one side of the lid such as to provide a mouth through which the container can be removed from the lid on sliding.
As the lid can be removed from the container by a sliding action, the force across the lid is minimised and thus the risk of damage occurring to the lid through repeated removal and replacement on the container is minimised.
The engagement means may be of any suitable form. In one arrangement the engagement means may simply be a wall which extends downwardly from the body of the lid and surrounds the outer wall of the container. However, the engagement means will generally include one or more lugs which cooperate with corresponding recesses on the container, one or more recesses which cooperate with corresponding lugs on the lid or a substantially continuous ledge which extends inwardly from a wall extending from the body and which in use sits beneath a ledge extending outwardly from the rim of the container.
In one embodiment, the body of the lid for a container is sized such that it covers the surface of the container. Engagement means will extend from at least a portion of the sides of the container. The locking means then includes a sheet extending collinearly with the body and attached thereto by a flexible web and extending beyond the fourth wall of the container. Integral with the sheet and depending downwardly therefrom will be suitable means for engaging the container. Suitable means include snap-clips. The locking means may include gripping means extending above the sheet to aid in the movement of the locking means. The gripping means may be of any suitable configuration.
In a second embodiment, the body of the lid for a container also comprises two parts of unequal size. In this embodiment, the combination of the two parts of the body of the lid cover the entire opening of the container.
In this case, a suitably shaped edge of the lid may be formed to provide both the engagement means of the first part of the body of the lid and the locking means for the second part. Again, the locking means may include gripping means.
Preferred features of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Figure 1: is a plan view from above of one embodiment of the lid of the present invention;
Figure 2: is a plan view from below of the lid of Figure 1;
Figure 3: is a side view of the lid of Figure 1 illustrated located on upper walls of the container;
Figure 4: is a schematic part cross-sectional diagram of the lid of Figure 1 illustrated located on upper walls of the container;
Figure 5: is a schematic part cross-sectional diagram of the lid of Figure 1 illustrated located on upper walls of the container viewed along the line BB in Figure 1;
Figure 6: is a plan view from above of the lid of Figure 1 with the locking means moved relative to the body of the lid;
Figure 7: is a side view of the lid of Figure 6;
Figure 8: is a part cross-sectional diagram along line CC in Figure 6;
Figure 9: is a plan view from above of a second embodiment of the lid of the present invention;
Figure 10: is a side view of the lid of Figure 9 illustrated located on upper walls of the container;
Figure 11: is a schematic part cross-sectional diagram of the lid of Figure 9 illustrated located on upper walls of the container as viewed along line DD in Figure 9;
Figure 12: a plan view from above of the lid of Figure 9 with the locking means moved relative to the body of the lid;
Figure 13: is a side view of the lid of Figure 12;
Figure 14: is a part cross-sectional diagram along line EE in Figure 12.

Referring to Figure 1, the first embodiment of the tamper-evident lid 10 for a substantially rectangular container comprises two parts of unequal size, a body 14 and a locking means 16. The body comprises an upper surface 14a and a lower surface 14b (see Figure 2) that together define a sheet. The locking means comprises an upper surface 16a incorporating a gripping means 18 and a lower surface 16b (see Figure 2) incorporating a plurality of snap-clips 30 (see Figure 2).
The body and the locking means are connected together by a web 20. The web is preferably co-axially located with two frangible flanges, the first flange 22 and the second flange 24 are positioned at opposing ends of the web. Both of these flanges are integral with the edge of the lid. The locking means and the body are generally formed from a single piece of plastics material and the web 20 comprises a section of the material of reduced thickness. Where the lid includes raised portions extending from the edge of the lid 31a, gaps 31 and 32 are incorporated into the edge of the lid in order to allow the movement of the locking means relative to the body.
As illustrated in Figure 2, the body 14 of the lid 10 covers the entire opening of the container 26 and is defined by an edge 12, shaped such that it cooperatively engages three sides of the rim 28 of the container. The locking means 16 extends beyond the remaining side 28a of the rim of the container. The lower surface 16b of the locking means comprises a plurality of snap-clips 30. These snap-clips cooperatively engage with the remaining side of the rim of the container. These snap-clips preclude the manual removal of the lid in any way other than that prescribed by the invention.
A frangible flange 24 and the gap 32 are particularly clearly shown in Figure 3. The flange and the gap are each positioned between the body and the locking means of the lid. A similar arrangement is located on the other side of the lid. A flexible web extends between the flanges. This web 20 is illustrated in Figure 4 which shows that it comprises a section of reduced thickness between the body and the locking means of the lid 10. Edge 12 engages with part of the container 26 to attach the lid to the container. Engagement means may extend around three sides of the container as illustrated in Figure 5.
Figure 6 illustrates the locking means 16 of the first embodiment rotated through 90 degrees relative to the body 14 along the axis of the web 20 (not shown). The flanges 22 and 24 fracture on the first such movement and flanges 22a and 24a are the remains of the frangible flanges. In some arrangements the frangible flanges may require breakage before movement of the locking means such as by the use of scissors.
The locking means rotated through 90 degrees is also illustrated in Figure 7. Here it is clear the requirement for the gaps 32. The raised rim may extend substantially around the whole edge of the container other than at the gaps 32. The edge of the rim at the gap may be shaped such that on rotation mitred edges 31a (not shown) and 32a are formed.
The disengagement of the snap-clip 30 from the rim 28a of the container is clearly illustrated in Figure 8. This disengagement releases the body of the lid and allows removal of the lid by sliding the body along the upper surface of the container, away from the disengaged portion 28a of the rim of the container.
Figure 9, illustrates an alternative embodiment of the tamper-evident lid 36 for use with a substantially rectangular container. The container comprises two parts of unequal size, a body 40 and a locking means 42. The body comprises an upper surface 40a and a lower surface 40b (see Figure 11) that together define a sheet. The locking means 42 comprises an upper surface 42a incorporating a gripping means 44 and a lower surface 42b (see Figure 11).
The two parts of the lid are connected by a flexible web 46. The web has a pair of frangible flanges 48 and 50 positioned at opposed ends of the web. The pair of flanges, together with gaps 54 and 56 that allow rotation of the locking means relative to the body are integral with the edge 38 of the lid. The body and the locking means may be formed from a single piece of material in which arrangement the web comprises a portion of the material of reduced thickness. Edge 38 engages with part of the container to attach the lid to the container. Engagement means may extend around three sides of the container. A rim may extend above the plane of the lid. Where a rim is included, the rim incorporates two gaps 54 (not shown) and 56 which are located above the frangible flanges 48 (not shown) and 50.
Figure 11 clearly illustrated that the body 40 and the locking means 42 of the lid 36 are connected by a web 46 that is of reduced thickness relative to these parts. The edge 38 of the body of the lid engages with the rim 58 of the container 26 in such a way that it precludes the manual removal of the lid in any way other than that described by the invention is prevented. The edge of the locking means of the lid cooperatively engages with the container to lock the lid in place.
In use, the locking means is moved in an arcuate manner such that it no longer engages the container. As illustrated in Figures 12 and 13 the locking means 42 is preferably rotated through 90 degrees relative to the body 40 and along the axis defined by the web 46 (not shown) thus exposing a portion of the rim 58. The flanges 48a and 50a are the remains of the frangible flanges 48 and 50 (not shown), fractured either by the action of scissors or of rotating the second part of the lid along the axis of the joint. This will depend on the end use to which the container and lid will be put. As in the previous embodiment, on rotation of the lid, the gaps 54 and 56 (not shown) have closed to form the mitred edges 54a (not shown) and 56a respectively.
As illustrated in Figure 14, once the locking means 42 has been rotated through 90 degrees relative to the body 40, the edge 38 of the locking means of the lid has been disengaged from the rim 58 of the container 26. The body of the lid may now be removed by sliding the remaining parts of the lid across the rim of the container, away from the disengaged portion of the rim.
The invention has been described with reference to a number of particular embodiments. It will be understood that any arrangement may be utilised which fulfils the requirement as set out on the claims of the application. In particular whilst reference to 90 degrees rotation has been made, any movement of the locking means may be utilised provided that the locking means disengages from the container. The lid may be configured to attach to any configuration of container.
Each feature of this specification (which term includes the claims) and/or shown in the drawings may be incorporated in the invention independently of other discussed and/or illustrated features.

Claims

A tamper-evident lid for a container, said lid comprising a sheet defining a body of the lid, engagement means for engaging the lid with the container and a locking means connected to the body by a web wherein the locking means is movable about the web from a first position in which the container is engaged to a second position in which the container is not engaged and wherein the locking means may be caused to move from the first position to the second position before the engagement means may be disengaged from the container.
The tamper-evident lid according to Claim 1 wherein the locking means rotates relative to the body of the lid and around an axis defined by the web.
The tamper-evident lid according to Claim 2 wherein the movement of the locking means will describe an arcuate path finishing at a position above the plane of the body.
A tamper-evident lid as claimed in any one of Claims 1 to 3 wherein the remaining parts are disengaged by sliding the lid from the container.
A tamper-evident lid as claimed in Claim 4 wherein the locking means extends along one side of the lid such as to provide a mouth through which the container can be removed from the lid on sliding.
A tamper-evident lid as claimed in any one of Claims 1 to 5 wherein the engagement means is a wall extending downwardly from the body of the lid and surrounding the outer wall of the container.
A tamper-evident lid as claimed in any one of Claims 1 to 5 wherein the engagement means comprises lugs which cooperate with corresponding recesses on the container.
A tamper-evident lid as claimed in any one of Claims 1 to 5 wherein the engagement means comprises recesses which cooperate with corresponding lugs on the lid.
A tamper-evident lid as claimed in any one of Claims 1 to 5 wherein the engagement means comprises a continuous ledge which extends inwardly from a wall extending from the body and which in use sits beneath a ledge extending outwardly from the rim of the container.
A tamper-evident lid as claimed in any one of Claims 1 to 9 wherein at least two frangible flanges extend between the engagement means and the locking means co-axially with the flexible web which when the locking means is first moved to the second position will break.
A tamper-evident lid as claimed in any one of Claims 1 to 10 wherein the body of the lid for a substantially rectangular container is sized such that it covers the surface of the container, engagement means extend from at least a portion of three sides of the container and locking means includes a sheet extending collinearly with the body and attached thereto by a flexible web and extending beyond the fourth wall of the container and having integral with the sheet and depending downwardly therefrom means for engaging the container.
A tamper-evident lid as claimed in Claim 11 wherein the means for engaging the container include snap-clips.
A tamper-evident lid as claimed in any one of Claims 1 to 10 wherein the body of the lid for a substantially rectangular container comprises two parts of unequal size, the combination of the two parts of the body of the lid covering the entire opening of the container, a suitably shaped edge of the lid is formed to provide both the engagement means of the first part of the body of the lid and the locking means for the second part.
A tamper-evident lid as claimed in any one of Claims 1 to 13 wherein the locking includes gripping means extending above the sheet to aid in the movement of the locking means.