LIDDED CONTAINERS

Abstract: A lidded container (1) is provided which is intended to deter unauthorised removal of the lid (2). The container has an out-turned lip (3) of inverted U-section having a circumferential horizontal flange (8) supporting an upright retention portion (10) with a retaining bead (12). The lid (2) has a rim portion (14) which is also of inverted U-section, the web (15) of the U having a formation (20) engaging a complementary formation (21) on the lip (3) of the container to provide location and sealing connection between the lid and container, and the outer limb (17) being outwardly cranked and forming a depending skirt (18) having a retaining formation (19) which interlocks with the retaining formation (12). Part of the flange (8) is extended to form a tab (22) which is removable at a line of weakening (23) to facilitate separation of the lid (2) and container (1). Removal of the tab (22) indicates that the container has been opened or at least that it has been tampered with.

Description: 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 usually have a lip which is turned over outwards, and is commonly of an inverted U-section. Their mating lids have a rim including a skirt which surrounds the lip. It is common also for the rim to be of an 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. When lidded containers are used to hold foodstuffs and other products for sale it is desirable that unauthorised opening 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. The present invention is concerned with lidded containers of the kind in which the container has a lip joined to a wall of the container and including a dependent limb which is spaced outwardly from an adjacent region of the container wall and has a downwardly and outwardly extending portion, reinforcing webs projecting from said adjacent region of the container wall and joined to said portion of the dependent limb at intervals around the container, and a circumferential flange, which is integrally joined to said portion, extends outwardly from the bottom of said portion and has an upstanding retention portion extending circumferentially continuously around the lip spaced opposite said portion of the dependent limb, and the lid has an upstanding rim of generally inverted U-section comprising a web and inner and outer dependent limbs which embrace and sealingly engage over the lip, said portion of the dependent limb extending downwardly and outwardly from adjacent to the bottom of the outer dependent limb to the circumferential flange, and a skirt integrally joined to, as a downward continuation of, the outer dependent limb, which extends circumferentially continuously of the rim outwardly of the outer dependent limb, is surrounded by the upstanding retention portion and is contained substantially within the height of the retention portion from the circumferential flange, and the skirt and retention portion having mechanically interlocking formations which restrain the lid from separation from the container until the retention portion is at least partially severed or removed from the lip. Such a container is disclosed in US-A-4 449 641 in which a depending flange of the lid embraces the container wall and a peripheral skirt spaced outwardly from the depending flange engages between the retention portion and the downwardly and outwardly extending portion of the dependent limb of the container, the interlocking formations are provided at the bottom of the skirt and the top of the retention portion, and the bottom of the skirt is spaced above the circumferential flange joining the retention portion and the bottom of the portion of the dependent limb. In GB-A-2 086 862 a lidded container is disclosed in which instead of the skirt there is an upstanding outer leg or flange joined to the outer limb of the lid, and the interlocking formations are provided at the top of the retention portion and the mid-portion of the upstanding leg or flange. The inner side of the upstanding leg or flange and the dependent container limb are separated by the outer limb of the lid. The rim of the lid is thus of a somewhat complex shape, and the upstanding leg or flange can be pressed inwardly to disengage the interlocking formations and release the lid from the container. The invention is characterised in that the web is relatively inflexible, the skirt depends into, or substantially into, abutting engagement with the circumferential flange and has a close circumferential engagement with the upper end of the surrounding retention portion which resists outward movement of the skirt, the interlocking formations are spaced from the bottom of the skirt and restrain the skirt from movement relative to the retention portion away from the circumferential flange, and the bottom of said portion is closely adjacent to the circumferentially inner side of the bottom of the skirt and thereby restrains the skirt from inward movement relative to the container wall which could separate the interlocking formations of the skirt and retention portion. Either one of, or both, the container and the lid may be of plastics material. A portion of the flange, or at least its retention portion, may be made to be severable or removable, for example by the provision of a line or lines of weakening so as to enable the mechanical interlock to be released. The arrangement has the advantage of deterring unauthorised opening, and of showing by the severing or removal of the said portion when the container has been opened. The entire flange or retention portion may be made to be removable but it is more convenient for just a portion to be removed. An interlocking engagement can still be obtained then between the skirt and the retention portion which, though more easily released, can nevertheless serve a useful purpose in retaining the lid on the container again after the initial opening. The web portion of the rim and an adjacent portion of the lid may have complementary male and female locating formations to assist in locating the lid on the rim of the container. If the lid is made of a plastics material such formations can be useful in reinforcing the resistance to unintentional release of the mechanical interlock between the skirt and the retention portion, for example as a result of pressure being exerted on the central part of the lid, as when the container is stacked with others, which might tend to distort the lid. The locating formations may comprise a circumferential bead of angular, conveniently rectangular, section on the one and a complementary groove in the other. The interlocking formations of the skirt and retention portion may be co-operating male formations such as beads or analogous projections which interengage, or they may be co-operating male and female formations, such as a bead and recess. The container may be of circular or non-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; Figure 3 is a fragmentary plan view of a corner of the container incorporating a tab; Figure 4 is a section along the line AA in Figure 3; Figures 5, and 6 are fragmentary sections showing modifications. In this embodiment the invention is applied to a rectangular lidded container. Both the container 1 and its lid 2 are made as plastics mouldings. The container 1 may be made of a high density polyethylene or a polypropylene, and the lid 2 may be made of a low density polyethylene or a polypropylene. They may be made of other suitable plastics materials. Referring to Figure 1, the container 1 has an outwardly turned lip 3 which has a lateral portion 4 and a depending portion 5 spaced from the circumferential wall 6 of the container. A lower part 7 of the depending portion 5 is outwardly inclined and is then extended outwards to form a circumferential L-shaped flange 8 which has a horizontal base limb 9 and an upright leg 10. At angularly spaced positions around the container there are reinforcing webs 11 between and joined integrally to the circumferential wall 6 and the depending portion 5 of the lip. The leg 10 of the flange, which constitutes a retention portion of the flange, is spaced outwardly from the outwardly inclined lower part 7 of the depending portion 5. An inwardly-directed retaining bead 12 at the upper end of the leg 10 extends continuously around the container. The retaining bead 12 has an under face 13 shallowly inclined downwards to the inside surface of the leg 10. The lid 2 has a rim 14 of inverted generally U-section comprising a relatively inflexible web 15 and inner and outer limbs 16 and 17 respectively. The outer limb 17 has an outwardly cranked lower part which forms a circumferential skirt 18. On the outside of the skirt 18 there is a retaining bead 19 having bevelled upper and under faces the upper face being inclined similarly to the under face 13 of the retaining bead 12 on the leg 10 of the flange 8. The lid pushes over the lip 3 of the container. The lateral portion 4 and the upper part of the depending portion 5 of the lip locate inside the U-section of the rim in close contact with the web 15 and upper part of the outer limb 17 of the limb, the adjacent part of the circumferential wall 6 being in close contact with the inner limb 16. The skirt 18 locates between the outwardly inclined lower part 7 of the lip 3 and the leg 10, the retaining bead 12 of the latter engaging over the retaining bead 19 of the skirt to provide a mechanical interlock which positively holds the lid on the container. In that condition the bottom edge of the skirt seats on the base limb 9 of the flange 8 and the skirt is contained within the height of the leg 10 from the base limb, as can be seen in Figure 2. There is sufficient resilience in the flange to allow it to be deflected sufficiently for the retaining beads to be interengaged and then to return to its normal state to hold them securely interlocked. The webs 11 resist distortion of the depending portion 5 of the lip 3. A locating bead 20 of rectangular section on the underside of the web 15 reinforces the web against flexure and engages in a complementary groove 21 in the lateral portion of the lip. Thus a good sealing connection is made between the lid and the container. The interengagement between the locating bead 20 and the groove 21 locates the rim on the lip and resists disconnection as a result of pressure being applied to the central part of the lid. At one corner of the container the base limb 9 of the flange 8 is extended outwardly to form a tab 22, Figures 1 and 3. The leg 10 and its retaining bead 12 are continued around the tab 22. A line of weakening is defined diagonally across the corner portion of the flange, at the root of the tab 22, by a slot 23 in the base limb which, as shown in Figures 3, 4, penetrates beneath the leg 10 of the flange at one side of the corner portion and extends almost to the leg at the other side of the corner portion. A V-section groove 23' extends the line of weakening upwards into the leg 10 of the flange and its bead 12 to facilitate disengagement of the interlocking retaining formations. The outer limb 17 of the rim 14 of the lid is similarly extended at the corresponding corner of the lid to form a tab 24, Figure 1, which overlies the tab 22 of the container and around which the skirt 18 is continued. The line of weakening enables the tab 22 of the container to be separated from the flange 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 retaining beads 12,19 being progressively disengaged as the lid is lifted. Because the skirt and initially the leg 10 extend continuously around the container, when their retaining beads are interlocked and the flange is intact it is difficult to release the lid from the container. A sufficient extent of the beads cannot readily be disconnected by distortion of the intact flange whilst the necessary upward force is simultaneously applied to the skirt to release the lid. Therefore as long as the flange is intact unintentional release of the lid is resisted and tampering is deterred. Only when the tab 22 has been separated at least partially from the flange can the lid be readily released. Once the tab has been separated there is, of course, visual evidence that the container has been opened, or at least that an attempt has been made to open it. The retaining bead 12 on the leg 10 of the remaining part of the flange 8 will interlock with the retaining bead 19 on the skirt when the lid is re-fitted on the container. In the modifications shown in Figures 5 and 6 of the drawings, the leg 10 of the flange 8 is shorter than that in the embodiment described and as shown in Figure 2. In each case the skirt 18 is at the lower end of an outwardly and downwardly inclined part 25 of the outer limb 17 of the rim 14 of the lid 2 of the lip 3 of the container, and is still contained, as shown, substantially within the height of the leg 10 from the base limb of the flange 8. The modification shown in Figure 5 has a step 26 in the skirt 18 which engages under the retaining bead 12 of the leg, and the skirt 18 is inwardly inclined below the step so that the lower end of the skirt is disposed inwardly of the retaining bead 12 and is able to pass the bead without interference, thereby facilitating insertion of the skirt past the bead. In the modification shown in Figure 6, the skirt 18 depends parallel to the leg 10 and it has a retaining bead 27 which is deeper than that on the skirt in the embodiment described. A further modification in Figure 5 is that the locating bead 20 is hollowed at an outer face 28 which lies adjacent an inner face 29 of the groove 21 on the lip 3 of the container.

Claims: A lidded container comprising a container (1) and a lid (2), the container having a lip (3) joined to a wall of the container and including a dependent limb (5) which is spaced outwardly from an adjacent region of the container wall and has a downwardly and outwardly extending portion (7), reinforcing webs (11) projecting from said adjacent region of the container wall and joined to said portion (7) at intervals around the container, and a circumferential flange (8) which is integrally joined to said portion (7), extends outwardly from the bottom of said portion and has an upstanding retention portion (10) extending circumferentially continuously around the lip (3) spaced opposite said portion (7) of the dependent limb (5), and the lid (2) having an upstanding rim (14) of generally inverted U-section comprising a web (15) and inner and outer dependent limbs (16; 17) which embrace and sealingly engage over the lip (3), said portion (7) extending downwardly and outwardly from adjacent to the bottom of the outer dependent limb (17) to the circumferential flange (8), and a skirt (18) integrally joined to, as a downward continuation of, the outer dependent limb (17) which extends circumferentially continuously of the rim outwardly of the outer dependent limb (17), is surrounded by the upstanding retention portion (10) and is contained substantially within the height of the retention portion from the circumferential flange (8), and the skirt (18) and retention portion (10) having mechanically interlocking formations (12; 19) which restrain the lid (2) from separation from the container until the retention portion (10) is at least partially severed or removed from the lip (3), characterised in that the web (15) is relatively inflexible, the skirt (18) depends into, or substantially into, abutting engagement with the circumferential flange (8) and has a close circumferential engagement with the upper end of the surrounding retention portion (10) which resists outward movement of the skirt (18), the interlocking formations (12; 19) are spaced from the bottom of the skirt and restrain the skirt from movement relative to the retention portion (10) away from the circumferential flange (8), and the bottom of said portion (7) is closely adjacent to the circumferentially inner side of the bottom of the skirt and thereby restrains the skirt from inward movement relative to the container wall which could separate the interlocking formations (12; 19) of the skirt and retention portion (10). A lidded container according to claim 1 characterised in that the flange (8) has a line of weakening formed in it at which a part of the retention portion (10) is separable from the remainder of the flange (8) to release the mechanical interlock between the formations (12; 19). A lidded container according to claim 2 characterised in that the line of weakening is defined by a slot (23) in and extending across said flange (8) and a groove (23') in the retention portion (10) extending from the slot (23). A lidded container according to claim 2 characterised in that a portion of the flange (8) is extended outwards from the container (1) to form a tab (22) around which the retention portion (10) extends, and the lid (2) has an associated portion which is correspondingly increased such that the lid forms a complementary tab (24) around which the skirt (18) extends and in that said line of weakening is formed at the tab-forming portion of the flange (8) such that said portion can be removed, thereby leaving the associated tab-forming portion (24) of the lid accessible for assisting subsequent separation of the lid from the container. A lidded container according to claim 1 characterised in that the mechanically interlocking formations of the skirt (8) and the retention portion (10) are interengaging male projections (12; 19). A lidded container according to claim 1 characterised in that the mechanically interlocking formations comprise a step (26) in the skirt (18) and a male projection (12) on the retention portion (10), the step (26) engaging under the male projection (12) and the skirt (18) being inwardly and downwardly inclined below the step such that a lower end of the skirt is disposed inwardly of the male projection and is able to pass the male projection without interference therewith. A lidded container according to any preceding claim characterised in that the lip (3) of the container has a lateral portion (4) adjacent to the web (15) of the lid, and complementary male and female locating formations (20; 21) are provided at the lateral portion (4) and the web (15) which assist in locating the lid (2) on the lip (3) and provide a sealing engagement between the lid and the lip.

Inventors: BAGNALL, PAUL JAMES HOWARD, LONGBOTTOM, KARL, WHITELEY, NORMAN
Applicants: PEERLESS PLASTICS PACKAGING LIMITED
Application year: 1988
Main classification: B65D43
IPC codes: B65D43