LID STRUCTURE FOR CONTAINER

Abstract

A lid is disclosed for a container having a peripheral wall extending to an upper edge and defining a product containing space. The lid structure comprises a lower frame, an upper frame and a lid. The lower frame connects to the upper edge of the tub and defines an access opening giving access to the product containing space. The upper frame is connectable to the lower frame in a snap-fit connection and forms a circumferential first seal therewith. The lid is arranged to close the opening, the lid and the upper frame forming a circumferential second seal. In this manner, an improved sealing connection can be achieved and the upper frame can be manufactured separately from the lower frame and joined thereto at a later stage of the production process.

Claims

1. A lid structure for a container having a peripheral wall extending to an upper edge and defining a product containing space, the lid structure comprising: a lower frame for connection to the upper edge of the container, the lower frame defining an access opening giving access to the product containing space; an upper frame, connectable to the lower frame in a snap-fit connection and to form a circumferential first seal therewith; and a lid, arranged to close the opening, the lid and the upper frame engaging to form a circumferential second seal.

2. The lid structure according to claim 1, wherein the snap-fit connection is located radially inwardly of the first seal.

3. The lid structure according to claim 1, wherein the snap fit connection comprises a plurality of downwardly extending barbs on the upper frame, which engage through detent openings in the lower frame.

4. The lid structure according to claim 1, wherein the first seal comprises an upstanding first rim on the lower frame, which engages within a downward extending first groove of the upper frame.

5. The lid structure according to claim 1, wherein the second seal comprises an upstanding second rim on the upper frame, which engages within a downward extending second groove of the lid.

6. The lid structure according to claim 4, wherein the first and/or second grooves are circumferential and are provided with lead-in structures that extend radially on both sides of the respective grooves by a distance at least equal to a width of the respective first and second rims.

7. The lid structure according to claim 1, wherein the upper frame has an external circumferential skirt and the lid has an exterior surface, the exterior surface and skirt being co-planar in the closed position of the lid.

8. The lid structure according to claim 1, wherein the upper frame has an external circumferential skirt and the lower frame has a peripheral surface, the peripheral surface and skirt being co-planar when the upper frame and lower frame are connected together.

9. The lid structure according to claim 1, wherein the lid is pivotally connected to the upper frame.

10. The lid structure according to claim 9, wherein the lid is arranged to pivot about a hinge located radially inwardly from an external periphery of the upper frame.

11. The lid structure according to claim 9, wherein the second seal commences engagement when the lid is at an angle of more than 15 to the upper frame.

12. The lid structure according to claim 9, wherein the second seal comprises an upstanding second rim on the upper frame, which engages within a downward extending second groove of the lid having a circumferential inner wall and a circumferential outer wall, wherein the circumferential outer wall extends downwards a distance greater than the circumferential inner wall in a region adjacent to the hinge.

13. The lid structure according to claim 1, wherein the first and second seals are insect-tight seals.

14. A package comprising: a container having a peripheral wall extending to an upper edge and defining a product containing space; and a lid structure, the lid structure comprising: a lower frame connected to the upper edge of the container, the lower frame defining an access opening giving access to the product containing space; an upper frame, connectable to the lower frame in a snap-fit connection; and a lid, arranged to close the opening.

15. The package according to claim 14, further comprising a membrane seal for sealing the product containing space prior to use.

16. The package according to claim 14, wherein the container is a thin-walled thermoformed tub having a wall thickness of between 0.1 and 0.6 mm.

17. The package according to claim 14, consisting of a single material class for the purposes of recycling.

18. The package according to claim 14, wherein the container further comprises a carton sleeve enveloping and supporting a thin walled, thermoformed tub.

19. The package according to claim 14, wherein the lower frame is permanently connected to the upper edge of the container.

20. The package according to claim 14, further comprising a quantity of powdered infant milk formula sealed within the product containing space.

21. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The features and advantages of the invention will be further appreciated upon reference to the following drawings of a number of exemplary embodiments, in which:

[0033] FIG. 1 shows a package according to the present invention in partly exploded perspective view;

[0034] FIG. 2 shows a perspective view of the package of FIG. 1 with closed lid;

[0035] FIG. 3 shows a perspective view of the package of FIG. 1 with opened lid;

[0036] FIG. 4 shows a partial cross-section through the package of FIG. 2 along line IV-IV;

[0037] FIGS. 5a to 5c show cross-sectional views similar to FIG. 4 during connection of the upper frame; and

[0038] FIGS. 6a to 6c show cross-sectional views taken in direction VI-VI in FIG. 3 during closure of the lid.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0039] FIG. 1 shows a partially exploded view of a package 1 having a lid structure 3 according to a first embodiment of the invention. The package 1 comprises a container in the form of a tub 2, a sleeve 4 and a membrane seal 6 and the lid structure 3 includes a lower frame 8, an upper frame 10 and a lid 12.

[0040] The tub 2 is thermoformed of relatively thin polypropylene material and has a base 14 and a peripheral wall 16 defining a product containing space 20. The peripheral wall 16 extends to an upper edge 18 having an outwardly directed flange 19. The sleeve 4 is formed of carton and has wall 22 and a bottom 24. Lower frame 8 is an annular ring having an upstanding first sealing rim 48 surrounding an opening 26 of a similar dimension to the product containing space 20. Between the first rim 48 and the opening 26 are located detent openings 46, the function of which will be further explained below. The upper frame 10 is also in the form of a ring and is provided with barbs 40 extending downwardly. The lower frame 8 and upper frame 10 are also made of polypropylene although it will be understood that other appropriate materials could be employed. The membrane 6 includes a tear line 28 defining an opening region 30 and includes a pull tab 32.

[0041] FIG. 2 shows a perspective view of the package 1 of FIG. 1 in the assembled state with the lid 12 closed. A catch 36 on the front edge of the lid 12, engages with a rib 38 on the upper frame 10 to maintain the lid 12 closed. The lid 12 and upper rim 10 are also made of polypropylene.

[0042] FIG. 3 shows a perspective view of the package 1 of FIG. 1 in the assembled state with the lid 12 open and the membrane removed to provide access to the product containing space 20. A scoop 42 is held within the lid 12 by clips 44 and can also be positioned in a scoop holder 50 integrally formed with the lower frame 8. Also visible are hinges 11 allowing pivoting connection between the lid 12 and the upper frame 10.

[0043] FIG. 4 is a perspective cross-section along line Iv-Iv of FIG. 2. As can be seen, the membrane 6 is attached across the flange 19 of the tub 2 and sandwiched by the lower frame 8 which overlies the flange 19. The flange 19, membrane 6 and lower frame 8 are all welded together to form a single relatively rigid rim structure. Upper frame 10 is mechanically engaged with the lower frame 8 by the downwardly extending barbs 40 that engage through the detent openings 46 in the lower frame 8. As can also be seen in this view, sleeve 4 closely engages against the peripheral wall 16 of tub 2, extending up to beneath the flange 19 to provide additional support. This allows the upper rim 10 to be snapped into the lower rim 8 without causing deformation or collapse of the tub 2.

[0044] According to an important aspect of the invention, the lid structure 3 is provided with two seals. A circumferential first seal is formed by the upstanding first sealing rim 48 which engages with a downwardly extending first groove 54 on an underside of the upper frame 10. A circumferential second seal is formed by an upstanding second sealing rim 56 on the upper side of the upper frame 10 which engages with a downwardly extending second groove 58 on the underside of the lid 12. Lead-in webs 60, 62 are located on either side of the first groove 54 and second groove 58 respectively.

[0045] FIGS. 5a to 5c show cross-sections at the location of FIG. 4 with the upper frame 10 in the process of being connected to the lower frame 8. FIG. 4a shows the upper frame 10 entering into initial engagement with the lower frame 8. The lead-in webs 60 of the first groove 54 engage against the upstanding first rim 48 and guide it towards the first groove 54. The barb 40 has entered into the detent opening 46.

[0046] In FIG. 5b, the upper frame 10 has been pressed downwards onto the lower frame 8. This may be achieved by pressing on the lid 12. According to an important design consideration, on pressing on the lid 12, the force F is applied against the upper frame 10 by the lead-in webs 62 of the lid 12. In this manner, additional pressure or deeper engagement of the second rim 56 into the second groove 58 is avoided. As the upper frame 10 is pressed downwards, the first rim 48 enters the first groove 54 and the barb 40 flexes into the detent opening 46.

[0047] FIG. 5c shows the upper frame 10 fully engaged with the lower frame 8 and the barb 40 locked in the detent opening 46. At this stage removal of the upper rim 10 is not possible without application of considerable force and breakage of the package. It is noted that the barbs 40 protrude into the interior of the tub 2 and cannot therefore be accessed from outside the package 1. It may also be noted that in the fully assembled position, the first rim 48 has not bottomed out in the first groove 54. This ensures that due to manufacturing tolerances, the barb 40 will not be impeded from connecting.

[0048] In this view it can also be seen that the upper frame 10 has an external circumferential skirt 66 and the lid 12 has an exterior surface 64. The exterior surface 64 and the skirt 66 are co-planar in the closed position of the lid 12. In other words, both of the lid 12 and upper frame 10 have external surfaces that blend smoothly together at this location. Additionally, the lower frame 8 has a peripheral surface 68 and the peripheral surface 68 and skirt 66 are also co-planar when the upper frame 10 and lower frame 8 are connected together as shown in FIG. 5c.

[0049] FIGS. 6a to 6c show cross-sections in the direction VI-VI of FIG. 3 with the lid 12 in various stages of closure onto the upper frame 10. In FIG. 6a, the lid 12 is in the open position supported by hinge 11. As can be seen, the position of the hinge 11 is at a radially inwards position with respect to the skirt 66 of the upper frame 10. This means that when packages 1 are stacked adjacent to one another, the hinge 11 does not protrude outwards and impede close stacking. It is also less likely to be caught or snag accidentally. It is also noted that at this position, there are no lead-in flanges 62 supporting the second groove 58 and an inner wall 58A is longer than an outer wall 58B of the second groove 58.

[0050] FIG. 6b shows the lid 12 in a partially closed position with the upstanding second rim 56 engaging with the inner wall 58A of the second groove 58. This contact occurs when the lid 12 is still at an angle of around 20 with respect to the upper frame 10. The downward extent of the inner wall 58A beyond that of the outer wall 58B ensures that the second rim 56 is guided into the second groove 58. In this case, the extended inner wall 58A acts as a lead-in structure and for this reason, no lead-in flanges 62 are required in this region. In fact, the absence of lead-in flanges 62 allows the inner wall 58A to more easily flex as the angle between the lid 12 and the upper frame 10 changes. Furthermore, the angular engagement on closing the lid 12 prevents the second rim 56 from entering into the second groove 58 in a linear manner. The lead-in webs 62 on the lid 12 assist in guiding this angled entry, ensuring a progressive engagement of the second rim 56 into the second groove 58, starting from the rear edge of the lid 12 adjacent to the hinge 11 and progressing around the circumference to the front edge of the lid 12 adjacent to the catch 36. In addition to assisting in guiding the second rim 56 into the second groove 58, the lead-in webs 62 also support the second groove 58 and help maintain its position. Because of the additional support provided by the lead-in webs 62, the structure forming the second groove 58 can be made more flexible allowing the closing action to be smoother. As discussed above, the manufacturing tolerances for the positions of these features is determined by the overall dimension of the opening 26.

[0051] FIG. 6c shows the lid 12 in the closed position, with the upstanding second rim 56 engaged with the second groove 58. As described already above, full engagement of the second rim 56 into the second groove 58 is avoided and the closed position of the lid 12 is defined by abutment of the lead-in webs 62 with the upper frame 10 and the exterior surface 64 engaging onto the skirt 66.

[0052] Thus, the invention has been described by reference to certain embodiments discussed above. It will be recognized that many modifications in addition to those described above may be made to the structures and techniques described herein without departing from the spirit and scope of the invention. Accordingly, although specific embodiments have been described, these are examples only and are not limiting upon the scope of the invention.