The present invention relates to a storage container, and in particular a storage container with a concertinas and a sealable top.

Storage containers such as Lock & Lock (RTM) storage containers are well known in the marketplace and resealable lids therefor are commonly provided thereon - attaching thereto using foldable clips. The adaptability of such storage containers, however, has generally been minimal. As a result, customers generally purchase a range of different sizes of storage container so that they can choose the most appropriate one for the product to be stored.

It is commonly the case that the storage containers will be placed in a refrigerator or storage cupboard, being removed and returned as the product therein is removed gradually over time - for example in portions. One problem that arises, however, is that due to the number of such storage containers, they can occupy a large amount of space in the refrigerator or storage cupboard, and that space does not diminish over time, i.e. as the product contained therein in consumed or used. It would be desirable, therefore, to provide a storage container that can more efficiently utilise the storage space available for it in the refrigerator or cupboard or the like.

Solutions for this have been provided in the prior art utilising a similar storage container - with its removable lid, but with concertinas along the sidewalls thereof so that the storage container can be collapsed as the contents are used - or for initial storage at a more appropriate volume for the contents placed therein. In this collapsed condition, the smaller volume is then maintained by closing or sealing the lid thereon, the lid thus sealing the top, potentially with a sealing valve, thus utilising vacuum pressures within the container to maintain the storage container in its collapsed state. The present invention looks to provide an alternative solution, or a variation of this prior art's solution, for further improving storage containers.

A further problem arises in the prior art solutions, especially those made with a collapsible form. This arises through the mode of manufacture used to manufacture the components of the containers - injection moulding. A cost efficient method for manufacturing a storage vessel from a polymer is blow moulding. Plastic bottles, for example, are commonly blow moulded. This is a preferred method over injection moulding since injection moulding is more costly. However, blow moulding is harder to control - in terms of wall thicknesses and material flow locations. This makes it difficult to provide a repeatable tight manufacturing tolerance, and that makes blow moulding a less common approach for sealable vessels. For example, the rim of the vessel against which a seal may need to be provided may have irregularities after blow moulding, which could compromise seal integrity for the finished vessel and lid assembly. For this reason Lock & Lock storage containers are generally injection moulded.

It should also be observed that injection moulding a vessel with concertinas down the sides of the vessel would be too costly anyway to be commercially viable in the domestic storage container market due to the complex internal and external form of the container required to achieve the concertina effect - a complex multi component injection mould would be needed.

The present invention therefore looks to provide an alternative method of manufacturing a collapsible storage container, or a lower cost production method for any storage vessel component of a storage container, while still ensuring adequate control of the detailing of the rim or lip of the vessel, thus enabling the maintenance of the desirable reproducibility of tight tolerances for maintaining a satisfactory repeatable seal between the lid and the vessel..

According to the present invention there is provided a storage container comprising a storage vessel and a lid, the lid comprising clips for attaching the lid to the storage vessel and a circumferential member for sealing with a lip of the storage vessel, wherein the lip extends around an upper opening of the storage vessel and is assembled onto a rim or flange of the storage vessel such that it seals with and grips onto the upper opening of the storage vessel, the lip comprising at least three separable components, including a retaining ring, a clamp ring and a sealing member, the clamp ring and the sealing member being retained within a groove of the retaining ring when the lip is in its assembled form on the upper opening of the storage vessel, and the sealing member being arranged to cooperate with the circumferential member to provide the seal between the lip and the lid once the lid is attached to the storage vessel.

The sealing member is preferably a sealing ring.

Preferably both the clamp ring and the sealing member grip opposing sides of a flange surrounding the upper opening of the storage vessel - the grip will thus be present around the full circumference or perimeter of the opening. The sealing member is preferably in direct contact with the flange around the full circumference or perimeter of the opening so as to provide a complete direct seal therewith.

The sealing member is preferably located next to the inside wall of the flange so as to be protected from direct contact from the outside.

The retaining ring can be arranged to contact the flange, but it need not be in contact around the full circumference or perimeter thereof. It can even be spaced therefrom around the full circumference or perimeter. The present invention is fully flexible in this respect, while still providing the required retention function for the assembly of the lip on the flange of the vessel. This flexibility in its relationship with the flange provides the desired repeatable seal integrity, even if there are wider variables in the flange's manufacturing tolerances - especially in terms of its edge's shape or flatness/uniformity. The smoothness, flatness or uniformity of the sidewalls of the flange is a parameter that is much easier to control or guarantee when blow-moulding a product than the final flange edge's shape or flatness/uniformity, and the present invention's lip design provides the seal on that controllable sidewall, rather than the edge, thus avoiding the need for tighter controls on the tolerances for the edge of the flange. This makes a blow moulding of the vessel a viable option, without any compromise on the reliability of the seal.

As for the retaining ring, the clamp ring and the sealing member, they can still be manufactured using conventional techniques - such as injection moulding. This then ensures their manufacturing tolerances can also be met - which tolerances may be tighter than those for the vessel. Preferably the lid comprises a groove sized to accommodate the retaining ring therein. This might be a close fit so as to ensure correct alignment of the lid with the vessel, or the lip thereof. It might even be a tight or push fit - enough to partially seal therebetween, or to cause the groove to grip the retaining ring. However, the primary seal, once the lid is clipped to the vessel, will be an engagement between the lid and the sealing member, not this groove - especially since the retaining ring, in the illustrated embodiments, has apertures in it anyway which would break any seal relative to the groove. These apertures can allow venting of the groove-space as the groove is located over the lip, which helps to ensure the clamped lid properly beds down onto the lip. The apertures may also be a consequence of the tooling used in the molding process for the lid - they allow the mould tooling to form undercuts, i.e. the catches used in the assembly of the components of the lid for holding the assembly together - by passing blades through the apertures onto those undercuts or catches.

The clips are preferably engaged with the clamp ring to secure the lid to the storage vessel.

Preferably there are four clips. Four clips is particularly beneficial when the storage container has a generally square or rectangular shape, be that with rounded corners or otherwise. Four is also a useful number for round containers or oval containers. It can also be useful for other shapes. A three sided storage container, however, might have three, and a small container might only have two, or three. Ideally the clips are numbered adequately to provide an effective clamp force around the full circumference or perimeter of the sealing member for ensuring a fluid seal is provided around that full circumference.

Preferably the storage vessel has concertinas - preferably horizontal ones (relative to the upper opening being uppermost).

Preferably there are between three and fifteen concertinas. However, taller containers, e.g. those for spaghetti, or having a height higher than 150mm, may have more - for example between 6 and 50, or between 1 and 3 per 20mm of extended, at rest, height. The concertinas allow the storage vessel to be collapsed to a shorter height than its extended, at rest, state. Preferably they allow a collapse to between 30 and 50% of the uncollapsed height.

Preferably the concertinas have an overcentre form so as to click down when collapsed. This can be so that they are individually self-maintaining in a collapsed state, rather than relying upon vacuum forces to retain a particular state of collapse, or a particular collapsed or part collapsed height.

Preferably the lid comprises at least one vent. Preferably the vent is bi-directional and openable and closable, allowing air in or out of the box, as desired.

Preferably the vent is operated by a sealing member or sealing cover for covering a hole in the lid. Preferably the sealing member is a hinged sealing member, or hinged sealing cover, although it might instead be a push-valve (sliding open or closed).

Preferably by lifting the sealing cover, the vent can be opened thus allowing air in or out of the box, as desired.

The vent may instead be one a directional valve or a rotatable closure.

Preferably the lid comprises a labelling component. This labelling component may be associated with, or located in alignment with, the vent. Preferably it is a label cover or a label member attached to the vent - or more preferably to the component from which the sealing member is hingedly attached. Preferably it too is a hinged member - preferably hingedly attached to the sealing member or cover or the component to which the sealing member or cover is attached. Preferably these are a separately formed component fitted to the lid, preferably with a push-fit, such as using one or more barbed fixing detail. The labelling component is provided to allow the container to be labelled. Preferably it is a cover or slot, covering or providing an area into which a paper label can be inserted, or a sticker affixed, or it might be, or it might have, a wipe-clean markable surface to allow a washable marker to write thereon.

Preferably the sealing member or cover is attached to the lid using a barbed fixing detail. It is most preferably hinged thereto, on an opposite side to the labelling component. Preferably the sealing member or cover and the labelling component, with, when provided, the barbed fixing detail, are formed together in a single moulding, although the sealing member or cover has also attached thereto the sealing ring or disk - preferably made from a softer material than the sealing membe or cover.

Preferably the vent comprises a separately formed sealing ring or sealing disk. The sealing ring or disk may be push-fitted over a flanged member of the hinged sealing member.

Preferably the lid when retained on the lip has a ridge, flange or elbow that engages with the sealing member of the lip to form the fluid tight seal between the lid and the storage vessel. This ridge, flange or elbow is preferably at an end of the groove in the lid, or is part of or is extending from the part of the lid that forms the groove, where provided.

Preferably the clips engage with the clamp ring for securing the lid onto the storage vessel. Preferably the clamp ring has a flange or more than one flange, onto which the clips can clip.

The present invention also provides a storage container having a concertina form thereon, the concertina form defined by a plurality of concertinas, wherein at least some of the concertinas have an overcentre form provided by a non symmetrical shape in section, with one leg being longer than the other in that section, such that said concertinas can individually be clicked down when collapsed and such that when clicked down it is individually self-maintaining in a collapsed state. Such an arrangement allows the storage container to retain a particular state of collapse, or a particular collapsed or part collapsed height without relying upon fluid pressure in the vessel, or vacuum pressure in the vessel, for providing vessel height stability.

By having individually click-downable concertinas, the storage container can be adapted to a number of different heights, each with a stable wall-height, such as one concertina elapsed, and the rest extended, two concertinas collapsed and the rest extended, three concertinas collapsed and the rest extended, etc. Preferably the concertinas extend around the vessel generally horizontally, i.e. parallel to the upper opening.

Preferably there are between three and fifteen concertinas. However, taller containers, e.g. those for spaghetti, or having a height higher than 150mm, may have more - for example between 6 and 50, or between 1 and 3 per 20mm of extended, at rest, height. The concertinas allow the storage vessel to be collapsed to a shorter height than its extended, at rest, state. Preferably they allow a collapse to between 30 and 50% of the uncollapsed height.

Preferably the storage vessel is generally round or oval, or curved at its corners.

It is preferred that the curvature of the outer extremity of the storage container has a minimum radius in vertical section (with respect to the upper opening) of not less than 30mm, and more preferably not less than 45mm. Preferred values are about 51 mm, about 59mm and about 74mm.

It is preferred that the curvature of the outer extremity of the storage container has a minimum radius in vertical section (with respect to the upper opening), of not less than 200% of the amplitude of the corrugations - the height between adjacent opposing peaks thereof, and more preferably not less than 300% or most preferably not less than 350%.

The storage container can have further features as per the previous aspect of the invention, including the lip and/or clips, and conversely these features of this second aspect can be provided on the container of the first aspect.

The present invention also provides a method of manufacturing a storage container having a lid and a storage vessel with a lip, the lip being formed of more than one ring component, and the lid having a main frame structure, the method comprising:

blow moulding the storage vessel, the storage vessel having formed thereon a flange at an upper opening thereof for receiving the lip;

injection moulding at least two of the components of the lip, and also the main frame structure of the lid; and assembling the at least two of the components of the lip onto the flange to form the lip thereon, the lip sealing against the vessel.

Preferably there are three components making up the lip that is assembled onto the flange.

Preferably all three are injection moulded.

Preferably the three components are all rings.

Preferably the components comprise a sealing member, a retaining ring and a clamp ring.

Preferably the retaining ring has a U shaped groove into which at least parts of the sealing member and clamp ring are assembled when assembling the components onto the flange.

Preferably the retaining ring clamps the sealing member and clamp ring on either side of the flange.

Preferably the main frame structure of the lid includes a plurality of clips for securing the lid to the lip or vessel.

A vent may be formed in the lid. The vent may comprise additional components for adding onto or into the lid. These additional components are preferably made using a method involving injection moulding.

Preferably the flange is formed before the blow moulding technique. In another preferred method, the flange is formed after the blow moulding technique.

The flange may even be formed while the blow moulding of the rest of the vessel is being performed. The storage container may be in accordance with any of those aspects previously described, or with any one or more of the preferred, exemplary, or optional features discussed above or below. These and other features of the present invention will now be described in further detail, purely by way of example, with reference to the accompanying drawings in which:

Figures 1 to 4 respectively show a perspective view, a plan view, a side elevation and a further side elevation showing a collapsed form, of a first embodiment of storage container of the present invention, the embodiment being also known as the mid size box;

Figure 5 shows a second embodiment - a perspective view thereof, this time it being more rectangular in plan, this embodiment being also known as the lunch box;

Figure 6 shows a third embodiment - larger than the first, but still generally square in plan, this embodiment being also known as the cake box; Figures 7 to 9 show a perspective view, a plan view and a side elevation of the lid of the embodiment of Figure 5 removed from the storage vessel - with four clips opened out to their co-planar, or moulded condition;

Figs 10 to 12 show a seal and label cover component prior to being applied onto the frame structure of the lid of the previous embodiments, with Figures 10 and 11 showing a sealing ring of Figures 44 and 45 present thereon and with Figure 12 showing the sealing ring removed therefrom;

Figure 13 shows a section through the storage container of Figure 5, i.e. the lunch box, with a lid sealed and clipped onto the storage vessel of the storage container, with the concertinas of the storage vessel in their expanded condition;

Figures 14 to 19 show the storage vessel of Figure 13 prior to fitting a lip thereto; Figure 20 shows a lid for the lunchbox container prior to application of the seal and label cover component, or hinged sealing member, thereto;

Figure 21 shows a storage vessel for the cake box embodiment prior to applying a lip thereto;

Figure 22 shows a lid for the cake box embodiment prior to applying the seal and label cover component, or hinged sealing member, thereto; Figure 23 shows a storage vessel for the mid-size storage container prior to applying a lip thereto;

Figure 24 shows a lid for the mid-size box embodiment prior to applying the seal and label cover component, or hinged sealing member, thereto;

Figures 25 to 27 show partial sections through the storage vessels of the above three embodiments showing details of the preferred corrugations, and the preferred flange detail; Figures 28 to 30 show a preferred arrangement for the lip for applying to the lunch box embodiment;

Figures 31 and 32 show a preferred arrangement for the lip for the mid size box embodiment;

Figures 33 and 34 show a preferred arrangement for the lip for the cake box embodiment;

Figures 35 to 37 show a preferred arrangement for the retaining ring of the lip of the cake box embodiment;

Figures 38 to 40 show a preferred arrangement for the clamp ring of the lip of the cake box embodiment; Figures 41 to 43 show a preferred arrangement for the sealing member of the lip of the cake box embodiment;

Figures 44 and 45, as mentioned above, show a preferred arrangement for the sealing ring for the seal and label cover component, or hinged sealing member, of Figure 10 and Figure 11 ;

Figures 46 to 49 show further details of the preferred lid for the cake box embodiment prior to application of the seal and label cover component, or hinged sealing member, thereto;

Figures 50 to 54 show further details and sections through the mid size box embodiment showing how the sealing ring and sealing member engage against opposing members of the lid or storage vessel to ensure a fluid-tight seal; and

Figure 55 shows a detail at the base of the mid size box embodiment to permit gripping of the base for facilitating extension of the collapsible storage vessel. Similar detail can be present on any of the box sizes, as illustrated by the base details of Figures 14, 21 and 23.

Referring first of all to Figures 1 to 4, a first embodiment of storage container 10 is shown. This storage container 10 comprises a storage vessel 12 and a lid 14 clipped thereon using four clips 16. In the lid 14 there is also a hinged sealing member 38 which will be described in further detail below.

The storage vessel 12 is an open topped, closed bottomed, generally tubular member that can be sealed generally around the perimeter of the lid by way of an interaction therewith through an applied lip 20. There is thus a circumferential member 18 there around (see Figures 13 and 54 for sections through the preferred sealing arrangements).

The storage vessel 12 in this embodiment has eight concertinas 34 to allow it to be compressible. Different numbers of concertinas can be provided. For example, the embodiment shown in Figure 5 only has six. The storage container 10 has a generally square shape, albeit with rounded corners. Other shapes are also possible including round, oval, triangular and further polygonal shapes or curved shapes. It is preferred, however, that all corners be rounded. Figure 5 shows one alternative shape, which is rectangular, accompanied again with rounded corners. Figure 6 shows a further shape - again square, but this time larger.

In the first arrangement shown in Figures 1 to 4 the outer dimensions of the container are approximately 229mm wide and approximately 229mm long with a maximum non- flexed extended height of 125mm. These sizes, and the ratios between them, are non- essential.

The term "maximum non-flexed extended height" is used to mean the height of the container with the concertinas extended but in a condition where internally or externally applied stresses, or non environmental stresses, are removed therefrom, i.e. a free- standing extended condition.

Upon collapsing the concertinas downwards this height can be substantially reduced. This embodiment compresses to a height of about 44mm. There is therefore a significant compression achievable by virtue of the concertinas. In this case, the compression is about 35% of the non-stressed height. Other embodiments may alter the angles of the walls of the concertinas (when moulding the vessel) to achieve higher heights initially, and thus greater height compressions. However, the degree of compressibility can preferably be limited to achievable fully compressed heights of between 25 and 60% of the uncompressed, free standing height.

Referring next to Figure 5, a second design of storage container is disclosed. It is rectangular, and smaller, with a shorter free standing height. In this embodiment, known as the lunch box embodiment, the rectangle is preferably about 204mm long and about 154mm wide, measured to the outsides of the clips 16 (as in the previous embodiment). The height of the container in the unstressed state is preferably about 104mm. Upon collapsing the corrugations, however, the collapsed height may go down to about 48.9mm. This is a compression down to 47% of the original height. Other sizes and compressibilities are again permissible through changes to the sizes of the walls and corrugations. Referring next to Figure 6, a third embodiment is disclosed. In this embodiment, the box is larger since it is intended to be a cake box. This may thus be referred to as the cake box embodiment. The previous embodiment was intended to be a lunch box. The first embodiment was intended to be a mid size box. The names and intended uses, however, are non-essential and non limiting as to function.

The cake box of Figure 6 is generally square, albeit again with rounded corners. It again has eight concertinas. In this embodiment, the preferred dimensions are about 303mm wide, about 303mm long, and about 150mm high. It is also compressible down to about 53mm upon compressing the concertinas. This is a 35% height following compression.

Different numbers of concertinas and different dimensions for the concertinas, sides, heights and lengths are also within the scope of the invention. The three illustrated embodiments are only being provided as examples.

Referring next to Figures 7 to 9, a preferred arrangement for the lid of the lunch box embodiment is shown. In these views, the clips 16 are shown folded out to a non- closed orientation - this may be the orientations they take when the lid is being moulded.

The clips are hingeably attached to the edges of the lid to allow them to be folded down to clasp the box shut.

In this embodiment, the hinged clips have two apertures provided within them. These are optional. They could be for engaging over prongs around the edge of the storage vessel for gripping thereon. However, they are in this instance to facilitate the moulding process - they provide access to latches 78, which can fold under a latching rim 76 of the lip, as discussed below. When the clips are clipping the lid onto the storage vessel, there is a downward bias for the lid against the vessel so as to ensure the seal therebetween is provided.

In this embodiment, four clips are provided since that provides a unilateral seal around the full circumference or perimeter of the lip 20. Different shapes of storage container may benefit from fewer or a greater number of clips. For example, if the box is an eight sided box, it may benefit from eight clips, although four clips might still be adequate, whereas if there was a circular box, three clips or even two clips might be adequate, although four is still preferred. If the box was instead a five sided box, then five clips might be provided. Other arrangements will also be apparent to a skilled person. The number of sides does not necessarily dictate the number of clips.

As can be seen in Figure 8, the lid 14 has thereon a seal and label cover component or hinged sealing member 38. This hinged sealing member is shown in greater detail in Figures 10 and 11 and in a further view thereof as shown in Figure 12 (in which a sealing ring 48 has been removed). The sealing ring 48 can be seen in situ in Figures 10 and 1 1. Further details of the sealing ring 48 can be seen in Figures 44 and 45.

In this embodiment, the hinged sealing member 38 is for covering over a vent or hole 36 in the lid (see, for example, Figures 20, 22 and 24). The vent or hole 36 allows venting of air either into or out of the storage container, e.g. when the lid is clamped onto the storage vessel 12. This allows the collapse or expansion of the concertinas.

As can be seen in Figure 10, the seal and label cover component or hinged sealing member comprises three sections. There is a first section which provides for the seal, a second or middle section which is the fixing bar. In this embodiment it has barbed fixing details 46 for attaching it to the structural frame of the lid. There is then a third section which in this embodiment provides a label or label cover member 42. Both the first and the third sections 38, 42 are hingeably attached to the fixing member. The label cover is optional but preferred. In this embodiment, it provides an underside space into which a paper label can be inserted for labelling the container. Instead, a surface may be provided onto which writing can be added - preferred arrangements make this a removable ink receiving surface to allow it to be rubbed off (when using a non-permanent marker).

There can also be arrangements in which a slot into which paper can be inserted is provided.

The other end - the end with the sealing ring 48, will now be described in further detail. As can be seen in Figures 11 and 12, that end has an underside which has a flanged member 50 extending therefrom. That flanged member 50 is sized to accommodate thereover the sealing ring 48. The sealing ring 48 thus has a hole in its centre for fitting over the flanged member 50.

The sealing ring is made of soft material to allow it to seal against the lid 14. Preferably it is a silicon sealing member, or TPE (thermoplastic elastomer). Preferably it is of a food grade material. The sealing ring 48 preferably has a diameter externally of about 14mm and an internal circular diameter of about 6.6mm. The size of the hole 36, however, will dictate the size needed for the sealing ring.

The hinged sealing member (all three parts) preferably has a total length of about 101 mm and a width of about 27mm. Other sizes are also permitted, or a completely different valve/vent design might be provided, such as those known for other forms of vessel, or on bottles.

The height of the flanged member 50 for receiving the sealing ring is shown to be about 5.1 mm from the opposing face of the hinged sealing member 38. Other heights are permissible too, depending upon the location or shape of the hole 36, or on the configuration of the hinged sealing member, or the hinge therefor.

The height of the barbed fixing detail 46 is shown to be about 6.85mm from the opposing side of the fixing member. Other lengths are permissible, or other forms of attachment may be utilised.

The barbed fixing details have barbs extending to the sides thereof to facilitate firm securement of the hinged sealing member and label cover to the lid 14. For this purpose, holes are formed in the lid's structure.

The distal end of the hinged sealing member 38 is shown to be rounded with convex corners 52 and a concave tip 54. The concave tip facilitates grasping the free end of the hinged sealing member 38 with a finger to facilitate lifting thereof for opening of the vent. These are optional details, but are beneficial. In the lid 14, underneath the hinged sealing member 38, a depression is provided around the hole 36 that is to be sealed closed by the sealing ring 48. This depressed area 56 is shown to be larger than the hinged sealing member 38, further facilitating the grasping of the hinged sealing member 38 by the user. Again this is an optional detail, but it is beneficial.

The lid 14 of this embodiment also features a circumferential recess or groove 58 in its upper side. This circumferential recess or groove provides a shoulder 60 for bearing against the upper lip 20 of the storage vessel 12 for providing a seal thereagainst. As can be seen in Figure 3, the underside of the circumferential recess or groove (its shoulder) has a finger or flange 62 extending therefrom for further improving the seal. This is further shown in Figure 54 and will be described in more detail later in the description.

The flange might instead simply descend from the underside of the lid.

Another arrangement might have and the shoulder descending directly from the underside of the lid, or it might simply be present at the underside, e.g. through a depression or deeper thickness of the mid-part of the lid, i.e. without a circumferential recess or groove 58 in the upper side of the lid.

Referring next to Figure 13, a cut away view of a preferred arrangement is shown. This particular view is a cut-away view through the lunchbox embodiment.

As can be seen, the six concertinas extend around the walls of the vessel 12, those walls ascending upwardly from a base wall 64.

The base wall in this embodiment has an approximate width of 124mm and an approximate length of 174mm. The concertinas of this embodiment thus extend generally outwardly from the base wall 64. Other embodiments might instead have the concertinas extending inwardly therefrom, for example such that the final inward wall 66 of this embodiment is effectively not provided, i.e. the upright 68 of the base 64 instead descends directly from the outermost point 70 of the lowest concertina 34. Other base wall arrangements are also possible, including somewhere between the two (for example like the flange 72 described below), or arrangements where the base is smaller than illustrated, or larger than the concertinas.

As for the upper end of the storage vessel 12, it defines an upper opening 22, as better seen in Figure 14. That upper opening 22 is surrounded by the uppermost flange 72, which in this embodiment is a linear flange 72 extending generally vertically, i.e. as a cylinder or hoop with respect to the then horizontal base wall 64.

The flange or rim 72 of this embodiment is shown further in Figure 19, and as seen it is located approximately midway with respect to the peaks of the concertinas (actually slightly inward of that mid-way point. This, just like the arrangement at the base, is optional but preferred. In other words, it could be larger or smaller than shown with respect to the concertinas. Further, in embodiments without the concertinas, it can still be larger or smaller than that shown.

This flange or rim is designed to be of a simple form, with minimal complex details, to allow the storage vessel 14 to be blow moulded at low cost. Blow moulding can be a low cost method for manufacturing flexible wall storage vessels, especially those having shapely exteriors with multiple inverting surfaces, such as concertinas. To injection mould such shapes would be very much more complicated as a complex multi-component mould would be involved, which would then make that process less cost effective.

Preferably the wall thickness for the flange is in the order of 0.5mm to 1 mm, or preferably about 0.67mm. It may be thinner or thicker, dependent upon strength requirements of the final product and the blow mouldability of the materials chosen, but these dimensions offer a good compromise on blow mouldability and material cost.

The preferred material for the vessel 12 is polypropylene (PP). Preferably it is made of a food grade polypropylene.

The other components of the container may be made using more conventional techniques for storage containers having snap-closable lids, such as injection moulding. By blow moulding this storage vessel, however, significant cost savings in terms of the production cost and material costs might be obtained (compared to injection moulding it). Another feature of the concertinas in this embodiment, and of the embodiments of each of Figures 1 to 6, is that they have a non-symmetrical shape in local radial section. As can be seen in Figures 25, 26 and 27, the lower wall of each concertina is arranged to be shorter than, and at a different angle to the horizontal than, the upper wall of each concertina. In this embodiment the upper wall is at an angle of about 32 degrees to the horizontal whereas the lower wall is at an angle of about 21 degrees to the horizontal. This occurs while still having a generally non tapering series of concertinas along the height of the vessel, so the radial/horizontal component height of both walls is the same (about 13mm in this embodiment). The concertinas stack above each other as well in a repeating manner - each being substantially identical, with the resulting saw-tooth waveform in section having a period length of about 14mm.

A similar arrangement is provided in the other two illustrated embodiments too, although the angles and ratios can vary. For example, in Figure 26 (the mid size box embodiment) the angles are about 28 degrees and about 16 degrees respectively. The radial/horizontal height (i.e. wave-form amplitude height) is instead about 14mm and the period length is instead about 13mm - i.e. shorter despite being higher. As for the embodiment of Figure 27 (the cake box embodiment), the angles are about 30 and about 20 with a height (amplitude) of about 16mm and a length (period) of about 16mm.

Different periods, different heights and different angles are also permissible, some ideas for which are presented below. Likewise, the positions of the different lengths may be reversed so that the upper wall is shorter than the lower wall. The illustrated arrangement is preferred, however, so that when the corrugations are collapsed, the top wall as shown (i.e. the longer wall) pushes down the shorter wall into a radially lower position than its hinge point. This enables any food or water contained on the walls of the vessel to drain out of the top of the vessel (when the vessel is inverted), rather than down into the peaks of the concertinas. This better facilitates drip-drying or emptying of the vessel when it is inverted (i.e. the contents are tipped out).

Further, due to the different lengths of the limbs of the concertinas, the concertinas also perform a further function, namely a click stoppable expansion or contraction of the concertinas such that a user can expand and contract the height of the storage container to pre-defined heights between the shortest and the longest free-standing lengths just by collapsing one or more of the concertinas. This thus functions much like a "bendy straw". This arrangement avoids the need for the sealable vent 36 to control the height or length of the container after it has been set by the user (e.g. to evacuate free airspace when the container is only part-filled with foodstuffs).

Because of this preferred click-down feature of the concertinas, it is also preferred that no sharp circumferential corners are provided around the cylindrical form of the vessel. Sharp corners in radial section are ok, i.e. as per Figs 13, 19, 25, 26 and 27, since they make a concertina form, but corners viewable in plan (i.e. Fig 15) that are preferably avoided. The reason that sharp circumferential corners (i.e. corners of a less than 10mm radius) are undesirable is that they can stiffen the actuatability of the concertinas, or cause the concertina action to produce undesirable stresses in the corners of the vessel, which can lead to unsightly, non-predefined, surface folding, or busts, in the sidewalls of the vessel. They can particularly cause difficulties with the click stoppable height adjustment feature since the localised stresses arising in such corners when the concertinas are fully folded (as in Figure 4) could be excessive, which is then likely to result in a failure of the wall of the storage vessel either immediately or at least soon after multiple flexures of the concertinas.

It is preferred that the minimum radius of such a circumferential corner (viewed in plan) around the circumference of the storage container is 20mm. As shown in the drawings, typically the radius will be larger than that. Compare, for example, with the dimensions discussed below, and elsewhere in this specification.

As for the angles of the limbs or walls of each concertina, preferably the angle of the shorter wall of each concertina is between 15 and 25 degrees from the horizontal (or from the plane of the base 64), whereas the angle of the longer wall is a larger angle - larger by at least 30% in preferred arrangements, and preferably an angle of between

25 and 40 degrees from the horizontal (or from the plane of the base 64). Note that these angles are defined by the angles of the walls when the vessel is in an at rest or free standing condition, i.e. in the condition they assume when no additional loading is positioned on the walls of the storage container and they are expanded, rather than collapsed.

Referring back to Figure 13, and forward to Figure 54, it can be seen that a lip 20 is fitted onto the uppermost flange or rim 72 of the storage vessel 12. This lip 20 is one of the preferred beneficial features of the present invention. Three embodiments thereof are shown in more detail in Figures 28 to 34, one for each storage container embodiment. Further variants will also of course be of note to the skilled person.

These three embodiments, and variants thereof, are particularly beneficial for providing a good seal at the top of the vessel, and they cooperate well with the design of uppermost flange of the vessels presented in these embodiments, i.e. a vertically arranged flange with a more horizontal support wall 74 connecting it to the uppermost concertina. In the illustrated embodiments, the more horizontal support wall is shown to be slightly angled relative to the horizontal - an angle of about 10 degrees. Other angles are also able to work with the illustrated lip designs and variants. For example, it could potentially be arranged at an angle of between 0 and 30 degrees from the horizontal in preferred embodiments. The lip's design can also be modified to accommodate steeper angles if preferred.

Referring to Figures 13 and 54, the lip 20 is shown to comprise three components, namely a retaining ring 24, a clamp ring 26 and a sealing member 28. The clamp ring

26 and the sealing member 28 lie either side of the flange 72 and the retaining ring 24 captures all three of these inside a groove provided therein so as to clamp or retain the clamp ring 26 and the sealing member 28 on the opposing sides of the flange 72. This clamping force, and the material of the sealing member, provides a secure and sealing retention of the lip 20 on the uppermost flange or rim 72 of the vessel 12. As shown in Figure 13, the clamp ring 26 can have outwardly extending latching fingers or a latching rim 76 for engaging by the clips 16 for securing the clips in their downward position for securing the lid 14 onto the storage vessel 12. Referring now to Figures 29 and 30, one arrangement of the retaining ring 24, clamp ring 26 and sealing member 28 for the lunch box embodiment is shown in more detail.

As can be seen, the latching finger, or rim 76 in this instance, extends all the way around the lip 20, as more clearly seen in Figure 29. It is provided to be engaged by a latch 78 provided on each clip 16 - see Figure 9. These latches 78, as shown in this embodiment, differ from the holes provided in prior art containers such as Lock n Lock RTM products, in that they extend away from the inside or underside if the clips 16 to engage a rim 76 of the lip of the storage vessel, rather than utilising catches extending away from the lip that are encapsulated by holes in the clips, as per the prior art. Prior art arrangements, however, may instead be preferred for some embodiments of the present invention - the continuous rim 76 is not essential. Likewise it might be preferred to provide providing intermittent latching fingers (not shown) around the lip 20, rather than a continuous rim, for offering compatibility with other lids. Regarding the components that make up the lip 20, the details of these will now be further discussed.

The sealing member 28 of the lip 20 is arranged with multiple faces that have separate functions, albeit all related to creating a reliable seal between the lid 14 and the lip 20 of the storage vessel 12, and between the lip 20 and the storage vessel 12 per se.

These faces include a first sealing side 80 which engages against the inside surface of the flange 72 of the storage vessel, a lower sealing side 82 which seals against the more horizontal support wall 74 of the storage vessel 12 and an upper sealing side 84 which gets borne against by the finger, flange or shoulder 60, 62 of the circumferential ridge or recess or groove 58 of the lid 14 once the lid 14 is clamped thereon. The sealing member 28 thus provides a very secure seal between the lid 14 and the storage vessel 12, thus making the storage container 10 reliably fluid tight during normal use of the storage container. The sealing member 28 also is provided with an annular groove 86, as clearly marked in Figure 42, which Figure relates to the sealing member design for a cake box embodiment. This groove 86 is a preferred feature to assist in ensuring a good connection and seal with the retaining ring 24.

As shown in Figure 41 , it is preferred that the sealing member has a generally constant cross section around its full circumference, i.e. no breaks or apertures.

The sealing member is preferably made of a silicon material, or some other commonly used seal material, such as a (preferably food grade) TPE (thermoplastic elastomer).

A particularly useful material is one with a Shore A hardness of between 40 and 70.

As with the other materials used in the various components of the storage container, preferred embodiments have a material and structure that is fully dishwater safe.

Referring next to Figures 35 to 37, further details instead of the retaining ring 24 are shown. Comparing Figures 28 and 30 with Figures 35 and 36, where two different sections through this retaining ring 24 can be seen, it is apparent from these that the cross-section of this retaining ring is not constant. Instead, it is only generally constant - it has intermittent apertures 88 provided there around.

The apertures facilitate the application of the retaining ring - they allow venting of the air-space presented by its groove.

In this embodiment, the apertures are tapered, in this case on only one side thereof, so as to have an enlarging width on its outermost end compared to the innermost end. In this embodiment, since the taper is only one sided, the other side thereof is square. Referring also to Figure 32, which shows the corresponding section for the cake box embodiment of Figures 35 and 36, it can also be seen that the general section throughout the majority of the circumference of the retaining ring 24 is generally U shaped with two descending legs, the innermost leg being shorter than the outermost leg. The legs might instead be of the same length if preferred. Both legs also have a chamfered or tapered or rounded end. These shapes are preferred over a squared off or sharp shape, particularly for the inner leg since it is to be accommodated in the groove 86 of the sealing member 28. By being rounded, preferably corresponding to the shape of the groove 86, the sealing member 28 should not be damaged by the interaction between the retaining ring 24 and the sealing member 28. The other leg can be more square if desired, with fewer consequences, since it would not be bearing against a component made of a more soft material, but nevertheless it is still preferred to be rounded so that it does not damage the component against which it does bear - the clamp ring 26 - and also so that it does not present a sharp edge to the user - it can be the external surface of the lip when the lid is not present.

That other leg, however, is more preferably designed to face or bear against the latching rim 76 of that clamp ring 26, as shown, so it can have a square end - that squared (or not squared) end may then offer a controlled depth of insertion over the clamp ring and sealing member when the lip 20 is being assembled.

The aperture 88, which may be tapered as shown, can allow venting of the enclosed space inside the retaining ring 24, and also serve to assist in the moulding of the retaining ring - they allow blades to be inserted through the ring to form the catches 92 as undercuts - these catches 92 are discussed further below.

The outer leg of the retaining ring 24 also has intermittently spaced around the inside thereof a plurality of catches 92. See Figure 36. Such catches 92 can be seen to be intermittent in Figure 35, where they can be seen through the apertures 88. This design is also apparent from looking at the alternative positional section of Figures 30, 32 and 34. Other catch forms might instead be used, however, so the apertures might not be present. These catches 92 are arranged to coincide with holes 94 provided in upstanding flange 90 that extends around the clamp ring 26. Figure 40 clearly shows the clamp ring 26 having these holes 94, which holes may be blind holes, but which in this embodiment are arranged to be through holes that extend partway through the upstanding flange and then downwardly out through the bottom of the clamp ring 26, as shown in Figure 39. These holes 94 interact with the catches 92 to lock the clamp ring 26 inside the retaining ring 24. This then also holds the sealing member 28 in place since it becomes encapsulated through its corresponding upstanding length inside the retaining ring - the length that provides the first sealing side 80 and the groove 86 relative to the inner leg of the retaining ring 24.

In Figures 30, 32 and 34, the gap between the sealing member 28 and the clamp ring 26 is illustrative only - in practice the lip is assembled onto the rim or flange 72 of the vessel 12. The gap this is of course there to accommodate the flange or rim 72 and the more horizontal support wall 74, as shown in Figure 13.

As already discussed, the clamp ring 26 has the rim 76 extending around it, or alternatively latching fingers. It also has a bottom flange or foot 96, which bottom flange 96 is arranged to lie underneath the more horizontal support wall 74 so as to prevent upward removal of the lip 20 from the storage vessel 12.

In preferred arrangements, the retaining ring 24 is made of a polypropylene, preferably a food grade polypropylene and is also dishwasher safe. Other mouldable materials may instead be used. It is preferred though that it is injection moulded. It is likewise preferred that the sealing member and the clamp ring and the lid are all injection moulded. As before, however, it is preferred that the storage vessel 12 is blow moulded.

With regard to the retaining ring 24, as can be seen in Figure 35, it is preferably generally square shaped in plan for the cake box embodiment. It would alternatively be generally rectangular shaped for the lunchbox embodiment and a smaller generally square shape for the mid box embodiment. Typical sizes would include a square of about 218mm or 293mm or a rectangle of about 143mm by 193mm. Other sizes are of course possible. The sealing member, flange and clamp ring are correspondingly sized too.

It is preferred that the corners be rounded as shown. This is like the shapes of the corrugations, as mentioned above.

The radiuses can be variable around the ring. For example, as shown in Figure 35, the primary parts of the side walls have a large radius or even a straight side. For example the radius might be 380mm or more, 389mm or more or 577mm or more respectively for the lunchbox embodiment, the mid size embodiment and the cake box embodiment. There is then preferably also a tighter radius in the corners, which radius may be 49mm or more, 58mm or more or 72mm or more, again for the lunchbox, mid size and cake box embodiments respectively.

In preferred arrangements, the radius in the corners is no less than 30mm or perhaps no less than 20mm. This provides a pleasant appearance for the product and also facilitates the functioning of the concertina elements where provided. The size of the concertinas are linked to the size of the lip due to their superpositional relationship when viewed in plan in these embodiments. Corresponding size limitations thus can also be applied to the concertinas.

As for the clamp ring 26, it is also preferably made of polypropylene (PP) - preferably a food grade PP. More particularly it is preferably made of the same material as the retaining ring and the lid. It is also preferably injection moulded.

The sealing member 28 is still preferably made of a softer sealant-suitable material such as thermoplastic elastomers, rubbers or silicones.

The hinged sealing member and label cover 42, 38 is preferably made of the same material as the retaining ring, for example PP or more preferably a food grade PP. Polypropylene (PP) is particularly useful in this respect since it is slow to fatigue so it is suitable for repetitive usage of the hinged clips - without rapid degradation of the preferred and illustrated moulded hinge joint from fatigue.

The sealing ring 48 to be applied to the hinged sealing member 38 is most preferably made from the same material as the sealing member 28. The hinged sealing member, however, is preferably made of the same material as the lid.

The materials are preferably transparent or semi-transparent although they can be opaque or coloured instead if preferred.

Finally, referring to Figure 55, a preferred arrangement at the bottom of the storage vessel 12 is provided. As can be seen, in the corners of the storage vessel there is provided a pinchable projection 98 provided by concavities 100 on either side thereof. These concavities are finger graspable to allow pinching of the corners to facilitate expansion of the concertina. This is an optional but preferred arrangement to facilitate use of the concertina function, and can be incorporated into a wide variety of base designs.

Although dimensions are provided or discussed herein for various elements of the invention, it should of course be appreciated that other sizes and dimensions and component size ratios will also be within the scope of the present invention.

These and other features of the present invention are described above purely by way of example. Modifications in detail made to the invention within the scope of the claims as appended hereto.