GB2340824A

GB2340824A - Container assembly

Info

Publication number: GB2340824A
Application number: GB9919428A
Authority: GB
Inventors: Steven Mark Long; Harold Edward Taylor
Original assignee: DOLPHIN PACKAGING MATERIALS
Current assignee: DOLPHIN PACKAGING MATERIALS
Priority date: 1998-08-21
Filing date: 1999-08-18
Publication date: 2000-03-01
Anticipated expiration: 2019-08-18
Also published as: GB9818247D0; GB2340824B; GB9919428D0

Description

2340824 CONTAINER ASSEMBLY The present invention relates to a container

assembly of the kind comprising a container body in the form of a tub or pot, and a container lid comprising a plug portion adapted to be received within the mouth of the body, the body and lid comprising respective flange portions extending outwardly of the mouth and substantially parallel to a plane extending across the mouth, the body flange and the lid flange initially being sealed to each other by a seal which can be broken by peeling the lid flange from the body flange. Such a container assembly will hereinafter be referred to as a 'container assembly of the kind set forth'.

Container assemblies of the kind set forth are useful for containing foodstuffs, such as double cream, which deteriorate once air has entered the container. The container assembly is tamper evident because the user will normally need to exert sufficient force on the lid to peel the lid flange from the container body flange, but if the lid has already been removed it will be apparent that a peeling action is not taking place.

A suitable heat-seal between the flanges is conveniently employed to provide the peelable seal.

Container assemblies of the kind set forth avoid the need for a separate closure member, such as a foil, which is often provided across the mouth of a container body to provide an initial tamper evident seal to the container assembly, the container lid extending across the closure member and having a depending skirt to engage around the exterior of the container mouth.

The known container assemblies of the kind set forth provide a loosefitting engagement of the lid with the body once the initial seal between 2 the lid flange and body flange has been broken. The known containers provide recesses on the plug portion of the lid which permit venting of gas from the headspace of the container body during initial application of the lid to the body prior to heat-sealing of the flanges. Since the container will normally be substantially full it is necessary to provide such a venting action, to avoid the central portion of the lid being bowed outwards by the pressure of gas trapped in the headspace.

The present loose-fitting lids do not provide a liquid seal, so if the container is knocked the contents can slop out.

The present invention is aimed at the problem of providing, in a container assembly of the kind set forth, adequate venting of gas from the headspace of the container body during application of the lid, yet providing an adequate retention of the re-applied lid to the body, and also providing a liquid seal between the re-applied lid and the container body.

According to the invention we provide a container assembly of the kind set forth in which the plug portion of the lid and the mouth wall of the body comprise respective co-operable annular sealing portions which are adapted to engage with each other in the fully re-applied condition of the lid to provide a liquid seal between the lid and body, the mouth wall or the plug portion being provided axially adjacent to the associated annular sealing portion with a plurality of generally axially-extending vents which by-pass the other annular sealing portion, when the lid is in a partially closed condition, to provide a venting action past said other annular sealing portion as the lid is being re-applied to the body.

It should be appreciated that the mouth and lid need not be round, but could instead be square, or oblong-rectangular, with rounded corners.

3 Accordingly the term 'annular' is intended to include when appropriate continuous strip-like features which are not necessarily of circular shape.

The axially-extending vents are preferably defined circumferentially between a plurality of circumferentially-spaced substantially radiallydirected protrusions which define detents adapted to assist in retaining the lid in a fully closed condition.

The body and lid are most economically produced by thermo-forming from sheet plastics materials.

In a preferred embodiment of the invention, in which the lid and body can conveniently both be produced by thermo-forming of sheet plastics materials, the annular sealing portion on the lid is in the form of a radially-outwardly directed annular bead provided on said plug portion of the lid towards the free end of the plug portion, that is, at the end of the plug portion remote from the lid flange, and said protrusions are protrusions formed in the mouth wall of the body, said other annular sealing portion being located on the mouth wall axially below the protrusions.

In this preferred embodiment the annular bead will snap past the protrusions, during application of the lid to the body, to reach a fully closed position of the lid, in which condition the annular bead on the lid seals with a plain annular portion of the mouth wall disposed just below the protrusions.

A pot and lid assembly in accordance with the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

4 Figure I is a side elevation of a pot, Figure 2 is an enlarged section on the line 2-2 of Figure I but showing two stacked pots, Figure 3 is a side elevation of a lid, Figure 4 is an underplan view of the lid of Figure 3, Figure 5 is an enlarged vertical cross-section of a pot with the lid in the fully-closed condition, the section being taken in a plane similar to 2-2 in Figure 1, that is, a vertical section through one of the protrusions in the mouth wall of the body, Figure 6 is a view similar to Figure 5, with the lid fully closed, but taken on the line 6-6 of Figure 1, that is, a vertical section through the mouth wall in a radial plane intermediate to a pair of protrusions, Figure 7 is a section in the same plane as that of Figure 6 but 15 showing the lid in a partially closed condition, and Figure 8 is a section on the line 8-8 of Figure 4 but showing two stacked lids orientated with their lifting tabs in register.

With reference to Figures I and 2, the thermo-formed plastics pot 1 is of generally tumbler shape and comprises a substantially vertical mouth wall 2, a frusto-conical lower side wall 3, an annular step 4 between wall 2 and 3, circular base 5, and a planar circular flange 6 extending radially outwards from the mouth. Mouth wall 2 comprises an upper, vertical mouth wall portion 7, of thickness comparable to the thickness of flange 6, and a lower, vertical mouth wall portion 8 of reduced thickness, vertically separated from the upper mouth wall portion 7 by a plurality of circumferential ly-s paced radially inwardly directed protrusions 9 and by a series of circumferentiaIly intervening vent formations 10.

The protrusions 9 are in the form of circurnferentially extending, elongate pockets which project radially inwardly of the mouth wall to a smaller radius than the radius of the lower mouth wall portion 8 thereby to define obstructions for snap-fitting of the lid, as will be described hereafter.

The vent formations 10 are each defined between a pair of the protrusions 9, the end walls of the protrusions 9 each acting also as end walls of the adjacent vent formations 10, which are also in the form of elongate pockets, but in this case the pockets forming the vent formations 10 extend radially outwards beyond the lower mouth wall portion 8. The lower edge of each of the pockets forming the vent formations 10 is defined by a horizontal shoulder 11.

The thermo-formed lid 12 comprises an annular plug portion 13, a central flat disc portion 14, and a peripheral lid flange 15 which is locally enlarged to provide a lifting tab 16, the flange 15 extending radially outwards from the upper end of the plug portion and lying in the same plane as the central disc portion 14.

The radially outer side wall 17 of the annular plug portion 13 is formed at the lower corner thereof with a radially outwardly directed annular bead 18 defined by sloping front and rear annular shoulders 19, 20, shown in Figure 8, and a sealing face 21. Sloping shoulder 19 assists in applying the plug portion 17 into the body mouth and in negotiating the protrusions 9, whereas sloping shoulder 20 assists in negotiating the protrusions 9 during removal of the lid.

6 With reference to Figure 7, on application of the lid 12 to the pot 1 the front shoulder 19 of the annular bead 18 engages with the sloping upper shoulders 22, Figure 2, of the protrusions 9 and on further downwards pressure on the lid the lid will be deformed to allow the bead 18 to negotiate the protrusions, whereupon the rear sloping face 20 on the bead 18 will cam on the lower sloping shoulders 23 of the protrusions 9 to drive the lid downwards, with a snapping action, to reach the fully closed condition of Figure 5 in which the sealing face 21 of bead 18 engages with a plain annular sealing portion 24 of the mouth wall 2, the 10 sealing portion 24 lying immediately below the shoulders 11.

As shown in Figure 7, when the lid is in the partially closed condition, the vent formations 10 define a plurality of axially extending vents 101 which bypass the bead 18 are thereby provide venting of the headspace of the pot during application of the lid. The vents 101 are only cut off just 15 before the bead 18 reaches the fully closed condition of the lid shown in Figures 5 and 6.

The underside of the lid flange 15 is provided initially with a coating of a suitable heat-sensitive adhesive lacquer to provide an initial heat seal between the flanges 6 and 15, this seal being capable of being broken by 20 a peeling action brought about by pulling progressively on the tab 16.

It will be appreciated that a significant pull is required on tab 16 to break the heat seal, which is arranged to be noticeable as compared with the force needed just to urge the bead 18 outwardly of the container past the protrusions 9.

If the container should have been tampered with by previous removal of the lid then the reduced force required to remove the lid and the lack of a 7 peeling action should be noticeable, and thereby provide a tamper-evident feature.

Lid 12 is provided adjacent to flange 15 with an annular locating shoulder 25 to provide a snug fit of the upper portion of the plug 5 portion 17 in the outer part of the pot mouth.

An orientation bump 26 is provided on the radially inner wall of plug portion 13 to help hold in register the tabs 16 of a stack of lids as shown in Figure 8.

I 8

Claims

1. A container assembly of the kind set forth in which the plug portion of the lid and the mouth wall of the body comprise respective co-operable annular sealing portions which are adapted to engage with each other in the fully re-applied condition of the lid to provide a liquid seal between the lid and body, the mouth wall or the plug portion being provided axially adjacent to the associated annular sealing portion with a plurality of generally axially-extending vents which by-pass the other annular sealing portion, when the lid is in a partially closed condition, to provide a venting action past said other annular sealing portion as the lid is being re-applied to the body.

2. A container assembly as claimed in claim 1, wherein the vents comprise ci rcumferenti ally- spaced radially -directed protrusions.

3. A container assembly as claimed in claim 2 wherein said protrusions project radially inwardly of the mouth wall of the body.

4. A container assembly as claimed in any one of claims I to 3, wherein the plug portion of the lid and the mouth wall of the body inter engage with a snap action.

5. A container assembly as claimed in any one of claims 2, 3, or 4, wherein said protrusions define detents adapted to assist in retaining the lid in a fully closed condition.

6. A (ontainer assembly as claimed in any one of claims I to 5, wherein the annular sealing portion of the lid is in the form of a radiallyoutwardly directed annular bead provided on said plug portion of the lid.

9

7. A container assembly as claimed in any one of claims 2 to 6, wherein said protrusions are formed in the mouth wall of the body.

8. A container assembly as claimed in any one of claims I to 7, wherein said other annular sealing portion being located on the mouth 5 wall axially below the axially extending vents.

9. A container assembly as claimed in any one of claims 6 to 8, wherein, during application of the lid to the body, the annular bead on the plug portion of the lid seals with a plain annular portion of the mouth disposed just below said protrusions.

10. A container assembly as claimed in any one of claims 1 to 9 wherein the lid comprises an annular plug portion, a central flat disc portion and a peripheral lid flange.

11. A container assembly as claimed in claim 10, wherein the peripheral lid flange provides a lifting tab.

12. A container assembly as claimed in claim 10 or 11, wherein the peripheral lid flange extends radially outwards from the upper end of the plug portion and lies in the same plane as the central disc portion.

13. A container assembly as claimed in any one of claims 1 to 12, produced by thermo forming of sheet plastics material.

14. A container assembly, substantially as hereinbefore described, with reference to the accompanying drawings.