WO1996027534A1

WO1996027534A1 - Lidded containers

Info

Publication number: WO1996027534A1
Application number: PCT/GB1996/000457
Authority: WO
Inventors: Stephen Leonard Cooke
Original assignee: Peerless Plastics Packaging Limited
Priority date: 1995-03-03
Filing date: 1996-03-01
Publication date: 1996-09-12
Also published as: GB9604383D0; GB9504277D0; AU4838696A; GB2298415A

Abstract

In a lidded container (1) comprising a container (2) and a lid (3), the rim (4) of the container includes an outer depending limb (6) which is mechanically interlocked to a skirt (16) of the lid by co-operating discrete formations (12, 18) provided at spaced portions around the container (2). The depending limb (6) has a circumferential flange (8) which extends outwardly underneath the skirt (16) and has an upstanding retention portion (10) which continuously surrounds at least a lower portion of the skirt (16) to resist relative movement between the skirt (16) and depending limb (6) such as might allow release of the formations (12, 18). The flange (8) is formed with a line of weakening at which a part (21) of the retention portion (10) is separable at least partially from the remainder of the flange (8) to enable the formations (12, 18) to be released. Unauthorised opening of the container is deterred, and is evident from tampering with the removable part (21) of the retention portion (10). By providing discrete formations (12, 18) around the container, these containers are more easily manufactured than conventional lidded containers.

Description

LIDDED CONTAINERS

This invention relates to lidded containers and more especially to such containers which are designed to deter and show evidence of tampering with their lids.

Lidded containers which are made of plastics material have a lip which is turned over outwards and is commonly of an inverted generally U-section. Their mating lids have a rim including a skirt which surrounds the lip. It is common also for them to be of a generally inverted U-section to push over the lip of the container so as to engage both inside and outside the lip. An air-tight seal can be achieved in this manner between the lid and the container.

It is desirable that unauthorised opening of lidded containers which hold foodstuffs, and some other products, for sale should be deterred not only to try to stop pilfering but also to prevent damage to or deterioration of the contents. It is important for it to be evident when unauthorised opening of a container has occurred, even if the lid has been replaced.

It is usual for there to be a snap engagement between the container and lid of a lidded container for the initial closed engagement of the lid with the container, and for subsequent closing after the first opening. Conventionally the snap engagement has been between the lip of the container and the skirt of the rim of the lid, and has been provided by the interengagement of a circumferential rib or bead formation on the one with a circumferential undercut or shoulder formation on the other. The provision of these circumferential formations has presented problems in the moulding of the container and lid. Precision shaping of the mould tools to define the formations is required. There can be difficulty in stripping the mouldings from the tools because of undercut formations in the mouldings necessitating the use of multiple stages of moving ejection. Also the stripping of the mouldings causes wear of the tools, requiring the tools to be replaced, otherwise flash will occur down the stripper plates. This is costly and interrupts production.

It is an aim of the present invention to avoid these problems.

According to the present invention a lidded container is provided comprising a container and a lid having a skirt which surrounds a rim of the container and has a lower portion, the rim being of an inverted generally U-section including an outer depending limb which is mechanically interlocked to the skirt by co-operating discrete formations at the depending limb and the skirt, characterised in that: the formations are provided at spaced positions around the container, and the depending limb has a circumferential flange at its lower end extending outwards underneath the skirt and an upstanding retention portion which continuously surrounds at least the lower portion of the skirt to resist relative movement between the skirt and depending limb such as to allow release of the interlocked formations, and the flange is formed with a line of weakening at which a part of the retention portion is separable at least partially from the remainder of the flange to enable the interlocked formations to be released.

The arrangement has the advantage of deterring unauthorised opening, and of showing, by the severing or removal of the said part of the retention portion, when the container has been opened.

The co-operating discrete formations may comprise projections, for example nibs, ribs or beads, on one or the other of the depending limb and skirt and complementary apertures, recesses or hollows in the other. Conveniently the projections are on the skirt of the lid. The apertures, recesses or hollows may be readily formed by local protrusions on the tool or tools by which the relevant component of the lidded container is formed. By virtue of the limited contact between the component and the tool or tools at the local protrusions, and the ease of ejection, with no moving stripping plates being required, the formed component may be readily separated from the tool or tools. Wear at the protrusions is minimised, and wear on stripper plates is eliminated.

Either one of, or both, the container and the lid may be of plastics material. Local protrusions or coring parts may easily be provided in the moulding tool for the relevant component.

In general a lower level of precision is required in the forming of the tool or tools to define the discrete formations of the depending limb and skirt than for continuous circumferential formations.

Preferably the skirt is engaged by, or is in close juxtaposition to, the surrounding retention portion so as to make it difficult for an implement to be inserted between them for an attempt to be made to prise the lid off the container. The lower portion of the skirt may have an outwardly directed part which overlies the circumferential flange of the rim where the flange extends underneath the skirt. The outwardly directed part may be inclined upwardly towards the retention portion. This inclination can ease re-engagement of the skirt of the lid inside the retention portion when once the separable part of the retention portion has been separated for the initial removal of the lid, thereby facilitating fitting of the lid to the container. The engagement of the skirt inside the retention portion may also be assisted by providing the retention portion with an outwardly turned upper end.

A portion of either one or each of the skirt and the flange, or at least the retention portion of the flange, may be made manipulatory to enable the interlocked formations to be released.

The container may be of square, rectangular or other non-circular shape, or of circular shape.

An embodiment of the invention will now be described by way of example only with reference to the accompanying drawings in which:

Figure 1 is a top perspective view of a lidded container in accordance with the present invention;

Figure 2 is an enlarged fragmentary section through a part of the container, and

Figure 3 is an enlarged fragmentary plan view of the container. As shown in Figure 1, a rectangular lidded container 1 is provided comprising a container 2 and a lid 3. The container 2 and lid 3 are plastics mouldings, for example the container being moulded from a high density polyethylene or a polypropylene and the lid being moulded from a low density polyethylene or a polypropylene.

The container 2 has, as best seen in Figure 2, an outwardly turned lip 4 which has a crest portion 5 and a depending portion 6 spaced from the circumferential wall 7 of the container. Extending outwards from the lower end of the depending portion 6 , away from the circumferential wall 7, is a circumferential L-shaped flange 8 which has a horizontal base limb 9 and an upstanding leg 10. The leg 10 is thus spaced outwardly from the depending portion; it constitutes a retention portion of the flange. The leg 10 extends upwards from the base limb 9 for more than half the depth of the depending portion and has an outwardly turned upper end part 10'. In alternative embodiments, the end part 10' may be replaced by a radius or chamfer to the upstanding leg 10.

At angularly spaced positions around the container are reinforcing webs 11, Figure 2, between and joined integrally to the circumferential wall 7 and the depending portion 6 of the lip. Also spaced around the container, at positions between the reinforcing webs 11, are a number of slots 12 formed through the depending portion, extending up into the lower region of that portion from its juncture with the horizontal base limb 9 of the flange 8.

The lid 3 has a rim 13 of inverted generally U-section comprising, as shown in Figure 2, a web 14, an inner limb 15 and an outer limb which forms a circumferential skirt 16 and has an outwardly and upwardly inclined lower part 17 of a width corresponding substantially to the upper side width of the base limb 9. Formed on the skirt 16 adjacent to, but projecting in the opposite direction from, the lower part 17 are nibs 18 which are positioned to engage in the slots 12 of the container, thereby to provide a mechanical interlock which positively retains the lid to the container. When the lid is so retained on the container the heel of the lower part 17 overlies the base limb 9 and the skirt 16 and outer edge of the lower part 17 closely engage the depending portion 6 and leg 10 respectively of the lip 4 of the container. The lower part 17 abuts the base limb 9. In an alternative embodiment, there may be a gap between these two elements. Similarly, when the lid is retained on the container, the circumferential wall 7 abuts the inner limb 15 of the lid. Again, in an alternative embodiment, there may be a gap between these portions to allow floating of the lid when lidding occurs. The upward inclination of the lower part 17 and the outwardly turned upper end part 10' of the upstanding leg 10 facilitate the entry of the rim 13 of the lid 3 between the skirt 16 and upright leg 10 so that the lid can be readily fitted to the container. There is sufficient resilience of the lower part to enable enough deflection of the skirt 16 for the nibs 18 to snap into engagement with the slots 12 and then hold them securely in the slots. The webs 11 resist distortion of the depending portion 6 of the lip.

The slots 12 are readily defined in the container as it is moulded by local projections of the moulding tool into the mould cavity. Since the projections are short and spaced around the cavity they enable the moulded container to be stripped quite easily from the moulding tool. Similarly the nibs 18 are easily defined in the moulding of the lid without imposing difficulties in the stripping of the moulded lid from its moulding tool.

At one corner of the container the base limb 9 of the flange 8 is extended outwardly to form a tab 21, Figure 3. The leg 10 is continued around the tab 21. A line of weakening is defined diagonally across the corner portion of the flange, near the root of the tab 21, by a slot 22 in the base limb which penetrates beneath the leg 10 at one side of the corner portion and extends almost to the leg at the other side of the corner portion. A groove 23 extends the line of weakening upwards into the leg 10 and into the outwardly turned upper end part 10' to facilitate separation of the leg and tab around the corner of the container. The lower part 17 of the rim 13 of the lid is similarly extended at the corresponding corner of the lid to form a tab 24, Figure 1, which overlies the tab 21 of the container. The line of weakening enables the tab 21 of the container to be separated from the flange 8 at least at the leg 10, at the groove 23, by cutting or tearing, for access to be gained to the tab 24 of the lid so that it can be manipulated to peel the lid off the container from that corner, the interlocked nibs 18 and slots 12 being successively disengaged as the lid is lifted. In an alternative embodiment, the line of weakening extends beneath the leg 10 at both sides of the corner portion, and two grooves are provided, one at either end of the line of weakening to extend this upwards into the leg 10 and upper end part 10'. Since the skirt and initially the leg 10 extend continuously around the container, when the nibs 18 and slots 12 are interlocked and the flange is intact it is difficult to release the lid from the container. The intact flange cannot be distorted sufficiently to allow the nibs to be withdrawn from the slots. As the leg 10 closely engages the outer edge of the lower part 17 of the skirt 16, and extends some distance above the lower part, there is little possibility either of a bladed implement or the like being inserted between the leg and the edge of the lower part 17 for an attempt to be made to prize the skirt 10 outwards away from the depending portion 6 of the container's lip, for separation of the nibs from the slots. Even if an implement could be inserted between the leg and edge of the lower part 17 the effect would be more to urge the nibs into the slots then to separate them. Therefore so long as the flange is intact unintentional release of the lid is resisted and tampering is deterred. Only when the tab 21 has been separated at least partially from the flange 8 can the lid be readily released. Once the tab has been separated there is then visual evidence that the container has been opened, or at least that an attempt has been made to open it.

When the lid is re-fitted on the container the nibs and slots interlock to hold the lid securely on the container. The upward inclination of the lower part 17 of the skirt 16 and the outwardly turned upper end part 10' of the leg 10 facilitate the insertion of the rim 13 of the lid between the depending portion 6 and leg of the lip 4 of the container.

Claims

1. A lidded container comprising a container (2) and a lid (3) having a skirt (16) which surrounds a rim (4) of the container (2) and has a lower portion, the rim (4) being of an inverted generally U-section including an outer depending limb (6) which is mechanically interlocked to the skirt by co-operating discrete formations (12,18) at the depending limb (6) and the skirt (16) , characterised in that: the formations (12, 18) are provided at spaced positions around the container (2) , and the depending limb (6) has a circumferential flange (8) at its lower end extending outwards underneath the skirt (16) and an upstanding retention portion (10) which continuously surrounds at least the lower portion of the skirt (16) to resist relative movement between the skirt (16) and depending limb (6) such as to allow release of the interlocked formations (12,18) , and the flange (8) is formed with a line of weakening at which a part (21) of the retention portion (10) is separable at least partially from the remainder of the flange (8) to enable the interlocked formations (12,18) to be released.

2. A lidded container according to claim 1, characterised in that the co-operating discrete formations (12,18) comprise projections on the skirt (16) of the lid (3) , and complementary apertures, recesses or hollows in the depending limb (6) .

3. A lidded container according to claim 1, characterised in that the co-operating discrete formations (12,18) comprise projections on the depending limb (6) , and complementary apertures, recesses or hollows in the skirt (16)of the lid (3) .

4. A lidded container according to claim 2 or claim 3, characterised in that the projections comprise nibs (18) , ribs or beads.

5. A lidded container according to any preceding claim, characterised in that the container (2) and/or the lid (3) is of plastics material.

6. A lidded container according to any preceding claim, characterised in that the skirt (16) is engaged by the retention portion (10) so as to make it difficult for an implement to be inserted between them for an attempt to be made to prise the lid (3) off the container (2) .

7. A lidded container according to any of claims 1 to 5, characterised in that the skirt (16) is in close juxtaposition to the retention portion (10) so as to make it difficult for an implement to be inserted between them for an attempt to be made to prise the lid (3) off the container (2) .

8. A lidded container according to any preceding claim, characterised in that the lower portion of the skirt (16) has an outwardly directed part (17) which overlies the circumferential flange (8) of the rim (4) where the flange (8) extends underneath the skirt (16) .

9. A lidded container according to claim 8, characterised in that the outwardly directed part (17) is inclined upwardly towards the retention portion (10) , which inclination eases re-engagement of the skirt (16) of the lid (4) inside the retention portion (10) when once the part (21) of the retention portion (10) has been separated for initial removal of the lid (3) .

10. A lidded container according to any preceding claim, characterised in that the retention portion (10) is provided with an outwardly turned upper end (10'), which assists engagement of the skirt (16) inside the retention portion (10) .

11. A lidded container according to any preceding claim, characterised in that a portion of the skirt (16) is manipulatory to enable the interlocked formations (12,18) to be released.

12. A lidded container according to any preceding claim, characterised in that a portion of the flange (8) is manipulatory to enable the interlocked formations (12,18) to be released.

13. A lidded container according to claim 12, characterised in that the portion of the flange (8) which is manipulatory is the retention portion (10) .