GB2600718A

GB2600718A - Storage containers

Info

Publication number: GB2600718A
Application number: GB2017524.6A
Authority: GB
Inventors: Campbell Hunt Patrick
Original assignee: Presso Ltd
Current assignee: Presso Ltd
Priority date: 2020-11-05
Filing date: 2020-11-05
Publication date: 2022-05-11
Anticipated expiration: 2040-11-05
Also published as: GB2600718B; WO2022096567A1; GB202017524D0

Abstract

The present disclosure relates to a storage container 1 comprising a closure 2 which fits inside a container and is slidable up/ down inside the container with its periphery in contact against the wall, defining a range of volumes of a storage space. The closure periphery 24 includes a groove directed outwardly towards the container wall and having upper 286 and lower limit 287 formations. A seal ring 22 in the groove is movable relative to the closure periphery within the groove, whilst engaging outwardly against the inner surface of the wall. The closure periphery incorporates at least one airflow channel 5 communicating between said groove and a face of the closure outside the groove, wherein the airflow channel is open for air flow when the seal ring is against one of said limit formations, and is (possibly partially) closed by the seal ring against air flow when it’s spaced away from one of said lower formations. The valves allow ready removal/ insertion of the closure. This container provides a substantially airtight storage-space and the variable capacity reduces the airspace above the contents, making it useful for storing and keeping foodstuffs fresh, particularly: grains, powders, beans or coffee.

Description

STORAGE CONTAINERS

This invention has to do with storage containers, preferably but not exclusively of the type often used for storing dry flowable or particulate goods such as foodstuffs, e.g. in the form of grains, granules, powders, beans or the like, such as those often known as storage jars. Containers for the storage of coffee beans or ground coffee are of particular interest.

BACKGROUND

Storage containers of the relevant kind have a container and closure (lid) which fits securely onto the container to isolate a storage space inside. One desirable feature is substantial air-tightness, to keep products dry and to avoid loss of volatiles which may be important for aroma or flavor of foods or drinks. Another popular feature is that the container be transparent or translucent, so that the goods, or at least the type/amount of the goods, can be seen from outside. Thus, long-standing designs include glass jars or bottles with screw-threaded lids or caps. Other containers use stoppers which wedge tightly into the container opening; these may have having annular ribs or flexible fins to enhance the seal.

When a container is partly empty, the substantial air volume above the product inside the container may be undesirable. It may represent a source of oxygen or moisture which can gradually degrade product quality. It may be a volume into which volatile product components, desired for e.g. flavor or aroma, might diffuse out and be lost. Some prior proposals have a closure including means for pumping out air from inside the container; this reduces moisture and can improve the lid seal. These closures are typically complex. Another proposal is for the closure to slide right down inside the container, which has a constant cross-section, until it lies on or closely above the mass of product. For this, some valve or venting action for air is needed to allow ready removal and/or insertion of the closure. Again, the corresponding valve components generally add complexity and cost to the product.

THE INVENTION

Having reviewed the state of the art, our aim is to provide a new storage container having a lid closure which can be moved down onto or close to the contained product, and which can be made with a relatively simple structure. In particular we propose a new structure for a closure periphery providing control of airflow.

Our proposal is a storage container comprising a container and a closure which fits into the container to define a storage space in the container; the container comprising a base and a surround wall standing up from the base, the wall having inward and outward surfaces and an edge defining a top opening; the closure fitting inside the container and having an upper face, a lower face and a closure periphery which engages around the inward surface of the container wall, the closure being slidable up and down inside the container with its closure periphery in contact against the wall thereof over a range of height positions corresponding to a range of different available volumes of a storage space defined in the container; characterised in that the closure periphery comprises a body portion defining a groove directed outwardly towards the container wall and having upper and lower limit formations, and a seal ring provided in the groove and movable relative to the body portion over a range of movement between the upper and lower limit formations, with the seal ring engaging outwardly against the inner surface of the wall, and the body portion of the closure periphery incorporates at least one airflow channel communicating between said groove and a face of the closure outside the groove, wherein the airflow channel is open for air flow when the seal ring is against one of said limit formations, and is closed by the seal ring against air flow (or is relatively less open) when the seal ring is at a position spaced away from said one of the lower formations.

In a preferred embodiment the body portion of the closure periphery incorporates at least one inward airflow channel communicating between said groove and the lower face of the closure outside the groove, wherein the inward airflow channel is open for inward air flow to below the closure when the seal ring is against said lower limit formation, and closed by the seal ring against air flow when the seal ring is at a position away from the lower limit formation. This feature provides for ready inflow of air to reduce the force needed for lifting out the closure. It will be appreciated that additionally or alternatively, depending on the user characteristics wanted for the container, the closure periphery may incorporate at least one outward airflow channel, controlled by the seal ring in the same way and references herein to the construction and operation of the inward airflow channel are applicable mutatis mutandis to an outward airflow channel except where the context requires otherwise.

By using the engagement of the seal ring against the container wall to drive the relative movement that provides a valve action, in concert with the lift applied to the closure by a user when raising the closure to open the container, this proposal enables a simple structure in which in preferred embodiments the seal ring may be the only relatively movable part of the closure. The degree of sealing provided is a matter of preference, since primary product protection is already achieved by eliminating the air-filled void above the product mass. With the closure lowered onto the product, the tendency for residual air to leave or enter the storage space is in any case small.

Preferably the seal ring is deformable, more preferably resiliently deformable, and most preferably it is of elastomeric material such as rubber. Its cross-sectional shape is not critical. At the least, it should be able to slide or roll against the wall surface and move up and down in the closure's peripheral groove. However a circular cross-section (0-ring type) is preferred because of its superior sealing combined with ready movement (compared with e.g. a blade-form or rectangular section) and a rubber 0-ring is suitable. Silicone is one suitable material. An elastomeric seal ring may be of hollow or foamed structure to moderate its outward force against the container wall and facilitate sliding. It may have an outer surface modified or adapted for reduced friction, i.e. relative to the friction of a surface of the unmodified polymer of the ring body.

Such low-friction surfaces are known and commercially available in the field of sealing rings.

The limit formations of the groove are preferably in the form of outward flanges or upwardly/downwardly-directed shoulder surfaces. They may extend continuously or discontinuously around the closure periphery. Their limit surfaces that engage the seal ring on axial movement are desirably substantially axially-directed, i.e. lying in a substantially radial plane: preferably their inclination at the contact region for the seal ring is not more than 200 or not more than 100 out of a radial plane.

The outward radial extent of the upper limit formation (or flange) is preferably less than that of the seal ring in 5 its free (uncompressed) condition and desirably leaves a clearance between the formation and the container wall to enable a flow of air between the exterior (above the closure) and the groove, so that the air can enter the mentioned airflow channel when it is not closed off by the seal ring.

The airflow channel may open into the groove at an upper region of the groove, so as to be closed by the seal ring when the seal ring lies against the upper limit formation e.g. flange. The other end of the airflow channel may open at the lower face of the closure into the storage space. Desirably the inward airflow channel is circumferentially-localised to facilitate manufacture. Its openings into the groove and storage space are preferably vertically aligned to facilitate manufacture, especially if the closure periphery is a moulded component as is preferred.

A circumferentially-localised airflow channel desirably subtends not more than 60°, not more than 50° or not more than 40° of circumference.

Preferably there are plural inward airflow channels, such as two or more or three or more, usually not more than 10. They can be circumferentially distributed, preferably uniformly.

The above-mentioned inward airflow channels admit air to facilitate withdrawal of the closure from the container.

The closure may also be adapted to facilitate or control airflow out of the container past the closure when it is inserted and pushed down. The seal ring then rides up against the upper limit formation (e.g. flange) of the closure, generally closing the inward airflow channel(s) so that seal ring makes its seal. In some cases it is preferred that air escapes only slowly as the lid is pushed down, since this may give a good user experience i.e. a sensation of sealing. Alternatively, some limited static or dynamic venting may be provided.

For example, one or more vent openings may be formed through the closure and may be a static vent (a simple hole, gap or bore) bypassing the seal ring/groove mechanism. This allows close adjustment of the necessary pushing force.

Optionally the vent may have a check valve mechanism such as a flap but this is usually not needed. For some uses a vent may be desirable e.g. if a stored product tends to give off gas. Additionally or alternatively a dynamic mechanism may be provided by having one or more outward airflow channels communicating between the groove and the exterior at the upper (outer) face of the closure wherein the outward airflow channel is open for flow when the seal ring is against the upper limit formation. This is usually not preferred because it is liable to leave the outward airflow channel open when the container is left closed, but may be acceptable in some cases.

Desirably the lid closure has a body, comprising integrally the body portion of the closure periphery, which is a single moulded piece defining a full closure in conjunction with the seal ring. It may however carry one or more ancillary components as discussed below.

Preferably the closure has a handle portion or grip, by which it can be held and lifted out of the container. This may take any conventional form, e.g. a D-shaped or C-shaped hoop. It may be attached to the body of the enclosure or be in one piece with it.

The seal ring material and ring and groove dimensions are preferably such that the friction of the seal ring can support the closure against gravity, i.e. so that it remains in the container at the height at which it is let go. The friction of an elastomer seal is useful for this.

The container is preferably of glass, but the material is not critical. Plastics, metal or other material may be used. Desirably the container is of substantially constant cross-sectional shape for most or all of its height. For ease of sealing, preferably that shape is circular or elliptical, although other shapes may be used if exact sealing is not needed and/or if any corner/angle regions are provided with adequate radius.

Since our proposals enable any necessary valve action to be provided around the periphery, the central region of the closure may be a simple plate, optionally with one or more static vent holes as mentioned. If a moulded component, the central plate may be thinner than the closure periphery structure. It may then lie above or below the groove, or at a median level, that is, it may be downwardly and/or upwardly recessed relative to the vertical extremities of the periphery. One option is that the closure plate lies at a relatively upper level, and a recess or cavity region is defined below the plate. A functional or passive material may occupy this cavity. For example a body of foam may be fitted in the cavity to exclude mobile air.

If necessary, such a foam body may have one or more vent holes, clearances or gaps communicating with one or more vents in the solid closure. Additionally or alternatively, a functional material such as a desiccant, oxygen scavenger or absorbent (such as activated carbon) may be provided in the cavity, e.g. attached to its surface or held within a carrier body such as a foam insert as mentioned above. The choice of these would depend on the product intended to be contained.

Generally it may be preferable that the closure body presents a flat and/or smooth lower face, to improve expected conformity to the top of a mass of product in the storage space of the container.

The size of the container may be as for conventional storage jars, e.g. food storage jars. Typically the maximum inner transverse dimension of the container (e.g. diameter or major diameter) is from 50 to 300 mm, more usually from 70 to 200 mm. The container wall normally stands up perpendicular to the base, but this is not critical and it might be generally inclined relative to the vertical.

DETAILED DESCRIPTION

Having described the concept and general features of 15 our proposals, examples are now described with reference to the accompanying drawings.

Fig. 1 is a perspective view of a storage container embodying our proposals, including a container and a closure shown at an intermediate degree of insertion.

Figs. 2 to 4 are diametrical vertical cross-sectional views showing schematically the action of the closure seal: Fig. 2 shows the closure removed from the container, Fig. 3 shows the closure during insertion into the container, and Fig. 4 shows the closure during withdrawal from the container.

Fig. 5 is a perspective view showing the underside of the closure.

Fig. 6 is a similar view of an alternative form of closure.

Fig. 7 is a schematic diametrical cross-section of the Fig. 6 closure showing an insert.

With reference to Figs. 1-4, a cylindrical container or glass storage jar 1 has a base 11 with a reinforcing plate, a vertical cylindrical sidewall 12 having a top edge 14 defining a circular top opening with a slight outward flare and an otherwise cylindrical smooth inner surface 13. A closure 2 consists of two components, a body 21 and a seal ring 22 fitted around a periphery 24 of the body. In more detail: the body 21 has generally the form of a circular disc sized to fit closely inside the container side wall 12, and having a grip or handle 25 projecting above the body which lies within the area envelope of the body so that the entire closure can enter the container as shown.

With reference particularly to Figs. 2-5, the closure body 21 includes a main plate portion 23 in the form of a 15 generally flat disc covering most of the closure area, and the body periphery or peripheral portion 24. The periphery 24 defines an upper flange 26 forming the periphery of the main plate, a lower flange 27 of similar radial extent and a groove 28 lying axially between the upper and lower flanges 26,27. All these formations extend continuously and uniformly around the body periphery. The groove 28 is defined by an upper face 286 corresponding to a downward shoulder of the upper flange 26, a lower face 287 corresponding to an upward shoulder of the lower flange 27, and an outwardly-directed face (base face 281). The upper and lower limit faces 286,287 lie substantially in respective radial planes.

The seal ring 22, in the form of an elastomeric 0-ring, such as a hollow (or foamed) silicone rubber 0-ring with a low-friction surface, lies in the groove 28 of the closure body. It is over-sized for the groove, so as to project radially beyond the radial extremities of the upper and lower flanges 26,27, as seen in Fig. 2 with the closure removed from the container. The radial extents of the upper and lower flanges are substantially equal. With the closure inserted into the opening of the container, as shown in Fig. 3, the 0-ring 22 makes interfering contact with the wall inner surface 13 while the upper and lower flanges maintain a slight clearance.

The closure is adapted to allow for passage of air between the exterior and a storage space S defined in the container 1 when the closure 2 is Inserted. Specifically, a set of inward airflow channels 5 is defined through the body periphery 24, each channel having an outward opening 52 which opens through the base 281 of the groove 28 (see Fig. 5) and an inward opening 51 which opens through the lower surface 232 of the body 23 into the storage space S directly. The outward opening 52 of the channel 5 occupies less than half the axial height of the groove 28, lying immediately beneath the upper flange 26. In the illustrated embodiment there are four airflow channels 5. This number is not critical, provided that adequate airflow is enabled. As seen in Fig. 5, they are constituted by a combination of axial and radial cavity portions so that they can be formed by withdrawable mould components. To maintain integrity, and enable a single closure body, each channel is confined to a minor angular extent of the periphery.

In addition to the airflow channels 5 the closure body 21 has a vent bore 234, provided here in the centre of the main plate 23 and extending right through it from the bottom face 232. In this embodiment it opens into the lower region of a diametrical slot 233 extending across the top face of the body 21. This slot is an optional feature enabling an identification card to be propped visibly on the lid by a user. The vent bore could of course open elsewhere.

Equally the transverse slot 233 might be absent or differently positioned.

The handle 25 is shaped in a vertical C-shape to facilitate both pushing and lifting of the closure.

Figs. 3 and 4 show the operation of the closure. After insertion -facilitated by the outward flare at the container opening 14 -it is pushed down into the container (arrow "I" in Fig. 3) and the seal ring 22 engages the glass wall with frictional sliding, riding to the top of the groove 28 and making a seal against the upper flange 26 which blocks the channels 5. A small air outflow is then possible around the seal 22 (as indicated by the arrows "AO" at these positions in the drawing), but this may not be significant or satisfactory especially because glass containers tend to vary in exact dimensions. Accordingly the vent bore 234, which has a closely predetermined dimension, operates to allow a predictable and substantial outflow rate of air (central arrow "AO") so that the closure can readily be pressed down onto the product in the storage space S until it meets the top surface of the product.

It is found that a controlled restricted outflow gives a satisfactory user sensation on pushing in the closure. When the user stops pushing, the closure remains in place, held by the friction of the 0-ring 22. The 0-ring also maintains a general seal, so that there is little exchange of air between the storage space S and the exterior through the tiny openings available. There is in any case very little air in the storage space, and little tendency for it to exchange with exterior air.

For removal of the closure 2 -see Fig. 4 -the user pulls up on the handle 25 (arrow "0" in Fig. 4). Frictional engagement of the 0-ring against the container wall now urges it against the lower flange 27 of the groove 28, away from the outward opening 52 of the airflow channels 5 so that these channels then open and complete an airflow path communicating between the storage space and the exterior via the clearance between the upper flange 26 and the container wall. The resulting inward airflow (arrows "AI") enables the closure 2 to be lifted up and out of the container without excessive force. The central passive vent 234 also contributes to air flow at this time to relieve the pressure difference.

Figs. 6 and 7 show an alternative embodiment of closure 2. Here the main plate 23 is thinner than the periphery 24, e.g. to avoid possible difficulties of moulding thick sections with some materials, or to reduce weight. In this embodiment the periphery 24 -which has the same form as described above for the first embodiment, and the same reference numerals are used -is relatively axially enlarged and extends downward relative to the main plate.

A cavity 29 is defined by the inward face 291 of the body periphery 24 and the upwardly-recessed bottom face 232 20 of the main plate. The airflow channels are formed in radially-enlarged inward boss regions 241 of the downward extension of the body periphery 24. The cavity may be functional. In this embodiment a foam disc insert 4 is fitted into the cavity so that the closure overall presents a generally flat bottom surface. This avoids trapping excessive air next to the product when the closure is lowered onto product in the storage space S. The insert may be used to carry a functional material such as a desiccant, antioxidant, oxygen scavenger or the like. Some types of product with coarse particles, grains, beans or the like (such as coffee) inevitably have air in the product mass, in which case such functional substances provided in the foam insert 4 may be particularly appropriate. If necessary a bore 41 or other clearance may be formed past or through the insert communicating with the vent bore 234 above, to ensure adequate air flow. A choice of open-cell or closed-cell foam, optionally covered (skinned) foam, can be made in line with the purpose thereof.

It will be understood that the provision of vents, and the precise mode of operation of the seal ring in relation to airflow channels, can be adjusted in dependence on the ergonomic behavior wanted. In any event, the closure construction is extremely simple and should therefore be economical to manufacture and reliable in use.

While the illustrated closure body 21 is of moulded plastics material, it will be appreciated that the structure is simple and a corresponding principle can be used with other closure materials e.g. wood, in which channels and vents can easily be bored.

Claims

CLAIMS1. A storage container comprising a container and a closure which fits into the container to define a storage 5 space in the container; the container comprising a base and a surround wall standing up from the base, the wall having inward and outward surfaces and an edge defining a top opening; the closure fitting inside the container and having an upper face, a lower face and a closure periphery which engages around the inward surface of the container wall, the closure being slidable up and down inside the container with its closure periphery in contact against the wall thereof over a range of height positions corresponding to a range of different available volumes of a storage space defined in the container; characterised in that the closure periphery comprises a body portion defining a groove directed outwardly towards the container wall and having upper and lower limit formations; a seal ring is provided in the groove and movable relative to the body portion over a range of movement between the upper and lower limit formations, with the seal ring engaging outwardly against the inner surface of the wall, and the body portion of the closure periphery incorporates at least one airflow channel communicating between said groove and a face of the closure outside the groove, wherein the airflow channel is open for air flow when the seal ring is against one of said limit formations, and is closed by the seal ring against air flow, or is relatively less open, when the seal ring is at a position spaced away from said one of the lower formations.
2. Storage container according to claim 1 in which the body portion of the closure periphery incorporates at least one said airflow channel which is an inward airflow channel communicating between said groove and the lower face 5 of the closure outside the groove, wherein the inward airflow channel is open for inward air flow to below the closure when the seal ring is against said lower limit formation, and is closed by the seal ring against air flow when the seal ring is at a position away from the lower limit formation.
3. Storage container according to claim 1 or 2 in which the seal ring is of elastomeric material.
4. Storage container according to claim 1, 2 or 3 in 15 which the seal ring has a circular cross-section.
5. Storage container according to any one of the preceding claims in which the limit formations of the groove are in the form of outward flanges or upwardly and downwardly-directed shoulder surfaces extending continuously or discontinuously around the closure periphery.
6. Storage container according to any one of the preceding claims in which the outward radial extent of the upper limit formation leaves a clearance between that formation and the container wall to enable a flow of air between the exterior above the closure and the groove, so that air can enter the airflow channel when it is not closed off by the seal ring.
7. Storage container according to any one of the preceding claims in which the airflow channel opens into the groove at an upper region of the groove, so as to be closed by the seal ring when the seal ring lies against the upper limit formation, and the other end of the airflow channel opens into the storage space at the lower face of the closure.
8. Storage container according to claim 2 or any one of the preceding claims depending on claim 2 in which there are plural inward airflow channels circumferentially distributed.
9. Storage container according to any one of the preceding 10 claims in which one or more static vent openings are formed through the closure.
10. Storage container according to any one of the preceding claims in which the lid closure has a body which is a single moulded piece defining a full closure in conjunction with the seal ring, and comprising integrally the body portion of the closure periphery.
11. Storage container according to any one of the preceding 20 claims in which the closure has a handle portion or grip by which it can be held and lifted out of the container.
12. Storage container according to any one of the preceding claims in which the container is of constant 25 circular cross-sectional shape over its height.