A metal cap

Abstract

The invention relates to a recyclable metal cap for a container, for example a food container, such as a jar containing dried herbs or coffee granules In one embodiment of the invention a wad for fitting to a mouth of a container has an adhesive layer which adheres the wad to a rim of the container and the wad has at least one shaped opening formed therein through which contents of the container are sprinkled once the container is opened. Ideally the wad is circular and is shaped and dimensioned to be received in a cylindrical container. The invention ideally uses a sealing type wad, or wadding material, which seals around an opening of the container. Bonding or sealing is achieved with conventional process equipment and sealing the wad is caried out for example by induction heat sealing or using a glue that reacts under pressure when a cap is fitted to the container. (Figure 4)

Description

[0001] A Metal Cap

[0002] Field

[0003] This invention relates to a metal cap for a container, more particularly but not exclusively, to a metal cap for a food container, such as a jar or tin.

[0004] Background

[0005] Food containers, especially jars that contain dried herbs and spices, often have a screw cap in order to ensure jars remain airtight and so prolong the shelf life of their contents. This is important for retailers such as supermarkets.

[0006] However, some food suppliers also wish to sell their herbs and spices with a so-called flapper cap. A flapper cap is a cap with a cap body that is attached to the cap and has a hinged element which flaps open to reveal an opening, such as dispensing mesh, which allows the contents to be sprinkled in a controlled way.

[0007] The flapper cap is usually formed from a synthetic plastics material and relies on the flexibility of its constituent material to form a hinge joint. The hinge joint allows the flapper to be opened and reclosed. The flapper cap may have an edge or raised pip which acts as a detent which deforms resiliently to enable the flapper to clip the cap shut and prevent spillage of the contents of the jar.

[0008] A problem has been that flapper caps cannot be easily and cheaply replicated in metal as continual bending of a metal hinge will be weakened and lead to failure.

[0009] Despite increasing legislative pressures in many countries to adopt more sustainable use of recyclable materials and ‘environmentally friendly’ manufacturing processes, because of the advantages of existing synthetic plastic flapper caps, there has been very little effort to develop an equivalent to the synthetic plastic flapper caps. Therefore, food manufacturers and suppliers requiring the functional features of synthetic plastic flapper caps have little option other than continue to use these types of synthetic plastics flapper caps which generally are not easily recyclable.

[0010] Attempts have been made to use a separate metal insert which fits in the opening of a container. These metal inserts have punched holes to enable the contents to be sprinkled in a controlled way in order to emulate the functionality of a flapper cap. However, disadvantages of these formed pierced metal pieces are that two metal parts have to be manufactured and have to be fitted to the container. Therefore, what at first sight appears relatively trivial and cheap in fact has required an additional process step during filling of the container and therefore has entailed substantial modifications to existing production and food container filling lines and the cost of an additional metal formed component.

[0011] Prior Art

[0012] German patent application number DE 39 07 422 (Luipold) discloses a bottle with an oversized pouring opening which has a film closure and a smaller air opening in the film closure.

[0013] French patent application number FR 2 616 758 (Etchebarne) discloses a plastics dispensing device for a bottle with an elastic membrane whose pores seal in their rest state and which open when the internal pressure of the bottle is increased, for example when it is squeezed.

[0014] United states patent US 4 284 200 (Sunbeam Plastics Corporation) discloses a plastics child-resistant dispensing closure for a container which has an open end. The closure has a skirt which mates with an end of the container and a top which spans the space defined by the skirt.

[0015] United states patent US 6341 720 (Sonoco Products Company) discloses a one-piece dispensing top with three separate dispensing ports. Each dispensing port is designed to dispense particulate foodstuffs from a container. One port allows removal of product with a utensil; a second port is used for pouring product and includes a spout, and a third port is for sifting a product.

[0016] United states patent application number US 2006 / 0060618 (Travis) discloses a dispensing closure system with two or more dispensing apertures and two or more pivotable lids. Each lid can be selectively opened and retained in a fully opened orientation.

[0017] United states patent application number US 2007 / 0007310 (Antal et al) discloses a dispenser top for loose materials with a flap attached to the dispenser top by a hinge along one edge of the flap. The hinged flap in a closed position overlies the dispenser top and closes one or more openings in the dispenser top and in an open position projects outward from the dispenser top. United states patent application number US 2008 / 0178903 (Thorpe) discloses a container for cosmetic products. The container has a removable cover with a protrusion and first and second sifters. The second sifter may be rotatably engaged with the first sifter.

[0018] United states patent application number US 2010 / 0230446 (Daggett) discloses a sift- resistant dispenser and closure. A sift deck contains a deck surface surrounded by a first snap bead and a first sealing surface and pouring holes formed on the deck surface.

[0019] United states patent US 5 513 781 (Phoenix Closures Inc) discloses a sifter and liner assembly which is configured for use with a container. The sifter is dimensioned to span the mouth of the container and has an upper surface, a lower surface and a least one aperture. The liner is dimensioned to cover at least the aperture of the sifter and includes an integral pull tab.

[0020] An aim of the present invention is to overcome problems associated with recycling many types of prior art removable caps, especially the types that are used to seal a jar or container in an airtight manner.

[0021] Another aim of the present invention is to provide a metal cap with a sifter and a wad which can be repeatedly re used to seal a container to achieve a similar result as existing flapper caps.

[0022] Summary of the Invention

[0023] According to a first aspect of the invention there is provided a removable metal cap and a wad for fitting to a mouth of a container, around an edge of one side the wad there is an adhesive layer which adheres an edge of one side of the wad to a rim of the container, a liner covers the wad and is retained in the removable metal cap to provide long term sealing in use, the liner is adapted to separate from the wad to reveal at least one shaped opening formed in the wad and the liner is retained in the removable metal cap, when the removable metal cap is first unscrewed, by a retaining means within the removable metal cap.

[0024] According to a second aspect of the invention there is provided a removable metal cap with a retaining means to retain a liner within the removable metal cap wherein the liner covers a wad that is fitted to a mouth of a container, the wad has an adhesive layer which adheres an edge of one side of the wad to a rim of the container and a temporary attachment on its other side which attaches the wad to the liner until the removable metal cap is first unscrewed, when the liner is retained in the removable metal cap by a retaining means, and separates from the wad, to reveal at least one shaped opening formed in the wad, and the liner is retained in the removable metal cap to provide long term sealing of the container by the removable metal cap in use.

[0025] It is appreciated that the removable metal cap may have a liner fitted therewithin and is then connected to a container with a wad already in situ around the rim of the container.

[0026] Alternatively, the liner and wad may be fitted to the removable metal cap which is then connected to the container such that an edge of the wad adheres to the rim of the container.

[0027] Alternatively, the liner and wad may be attached to the rim of the container prior to the removable metal cap being connected to the container such that the retaining means engages an edge of the liner prior to first removal of the removable metal cap from the container.

[0028] In most embodiments the wad is circular as it fits against and around a circular opening of the container.

[0029] The liner is preferably resiliently deformable so when pressed against the rim of the container it forms an airtight seal.

[0030] On first opening of the removable metal cap, if the liner and wad are adhered one to another, the liner peels away from the circular wad which remains bonded to the rim of the container. Peeling away of the liner reveals apertures, such as a sprinkle mesh, in the wad. Importantly however, whether fitted separately or as a single piece, from which two pieces are separable on opening, the liner is always retained in the cap and so is not discarded. By retaining the liner within the removable metal cap, it acts as a seal against the wad, which is attached to the rim of the container, when the removable metal cap is screwed back onto the container. Thus, the retained liner ensures that, despite the removable metal cap being metal, an airtight seal is repeatedly achievable even when the wad has openings, thereby improving the shelf life of the contents of the container. This advantage of the present invention therefore is that it enables a conventional threaded metal cap to be used to seal more efficiently once first opened in order to preserve the container contents, such a dried powders, coffee granules and dried herbs and spices. This is because the liner which is retained in the metal cap has a resilience and so deforms around a rim of the container to seal it.

[0031] When the removable metal cap is replaced on a container it presses and seals around the upper rim of the container, by way of a compliant region of a resi liently deformable portion of the liner thereby rendering the container to which the removable metal cap is attached airtight. This is required as metal caps tend to be a loose fit, only being machined to a tolerances which are not airtight in use. Also, metal caps after prolonged usage tend to deform and so threads are even more prone to poor sealing.

[0032] Therefore, the present metal caps with the liner consistently provide an airtight seal and so the contents do not spoil or go stale.

[0033] In some embodiments the wad is circular in shape and is shaped and dimensioned to be received on a cylindrical container, such as a tin or glass jar.

[0034] The invention ideally uses a sealing type wad, or wadding material, which seals around an opening of the container. Bonding is achieved with the sealing type wad or wadding material for example by induction heat sealing or using a glue that reacts under pressure when the removable metal cap is fitted to the container.

[0035] In some embodiments the wad or wadding material, (hereinafter wad) has openings of different sizes. For example, the openings may comprise at least one larger first opening and a plurality of smaller second openings.

[0036] The second openings are of the same size and optionally of the same shape.

[0037] Preferably the plurality of second openings is substantially circular.

[0038] In some embodiments the area of the larger first opening exceeds the combined area of the smaller second openings.

[0039] Preferably the combined area of the second openings is less than 20%, preferably less than 15%, and more preferably less than 10% of the area of the larger first opening. In some embodiments the smaller second openings are circular and have diameter which is preferably less than 25% of the diameter of the mouth of the container, more preferably less than 10% of the diameter of the mouth of the container and most preferably less than 5% of the diameter of the mouth of the container.

[0040] Preferably the larger first opening is in the shape of a circular segment, disc segment or is crescent shaped.

[0041] Ideally the wad has an induction heat sealant or pressure sensitive glue coated on at least a portion of one of its surfaces, preferably around an outer periphery thereof.

[0042] Although the wad may be supplied as pre-cut discs or on a roll, optionally the removable metal cap used to close the container may include the wad by way of a retaining means which may be the effect of a screw form in the wall of the removable metal cap or for example one or more protrusions, beads or ridges on an inside wall of the removable metal cap.

[0043] The liner is separable when the removable metal cap is first unscrewed to reveal the at least one shaped opening formed therein which ideally functions as a sprinkle mesh sealed to the top of the container. Importantly the liner is not discarded (unlike in many prior art devices) but is instead retained by retaining means, such as the effect of the screw form in the wall of the removable metal cap and / or for example by one or more protrusions, beads or ridges on an inside wall of the removable metal cap and used for airtight sealing of the liner in ongoing use.

[0044] Advantages of the invention are that it enables a conventional threaded metal cap to be used to provide a good seal and thus no modification of existing production and food container filling lines is required.

[0045] A yet further advantage is that the consumer has the option to retain the wad, which provides a sprinkler or to remove it, by peeling off the wad to reveal a spoonable container, with a wide mouth opening, as is currently available.

[0046] Another advantage is that the producer may use the layout, size, shape or configuration of either the smaller openings or the larger opening, for branding purposes, or for displaying a logo, or for indicating other visual information which may relate to the type or nature of the contents of the container. According to a third aspect of the invention there is provided a method of fitting a removable metal cap with a liner and a wad therewithin, to a container, the removable metal cap has a means to retain the liner which is temporarily attached to the wad; and bonding an edge of one side of the wad, by way of an adhesive layer, to a rim of the container.

[0047] According to a fourth aspect of the invention there is provided a method of fitting a removable metal cap with a liner retained therewithin to a mouth of a container which has a wad attached thereto, the removable metal cap has a means to retain the liner, whereby when the removable metal cap is fitted to the container the liner is temporarily attached to the wad.

[0048] The liner is temporarily attached to the wad until first removal of the removable metal cap which separates the liner from the wad, to reveal at least one shaped opening formed in the wad.

[0049] According to a fifth aspect of the invention there is provided a method of fitting a removable metal cap to a mouth of a container which has a liner and a wad attached thereto, the removable metal cap has a means to retain the liner, whereby when the removable metal cap is fitted to the container the liner is temporarily attached to the wad.

[0050] Again, the liner is temporarily attached to the wad until first removal of the removable metal cap which separates the liner from the wad, to reveal at least one shaped opening formed in the wad.

[0051] The invention will now be described, by way of examples only, and with reference to the following Figures in which:

[0052] Brief Description of the Drawings

[0053] Figure 1 shows an overall view of a wad according to one example of the invention, before it is fitted to a container (jar);

[0054] Figure 2 shows an overall view of the jar with the wad sealed onto its open end (mouth);

[0055] Figure 3 shows an overall view of the jar, with the wad sealed thereto, and with a removable metal cap for placement on the jar; Figure 4 shows an overall view of the jar with the wad sealed thereto and with the removable metal cap and a liner, shown in part-sectional view, fitted to the jar and with a seal created between a top edge of the mouth of the jar and an underside rim portion of the wad; and

[0056] Figures 5A and 5B show overall and exploded views of a section through the removable metal cap and the location of one example of a retaining means.

[0057] Detailed Description of Preferred Embodiment of the Invention

[0058] Figure 1 shows an example of a container (jar) 10 before being fitted with a wad 20 onto an opening (mouth) 30 at the top of the jar 10. The jar is glass and is open ended with a circular rim 32 defining its mouth 30 and has a threaded part 35 for receiving a threaded removable metal cap 50. However, in other examples, container the jar or rim may have a different shape and the jar may be made of different materials such as metal or a synthetic plastics material. Figure 1 shows a view of the wad 20 before it is fitted to the jar 10.

[0059] Figure 2 shows an overall view of the jar 10 with the wad 20 sealed around its periphery onto rim 32.

[0060] The wad 20 has a shape which generally conforms to the shape of the open end 30 of the container 10 and has a plurality of cut-outs or openings formed therein. In preferred embodiments there is at least one larger first opening 40 and a plurality of smaller second openings 42A, 42B, 42C. These smaller second openings are shown as circular cut outs or perforations, although they may take a variety of forms such as slots or be oval in shape. The at least one (main) larger opening or cut-out 40 is preferably generally segment shaped, such as a circular segment, crescent or a disc segment, or may take the form of a brand or logo or visual representation of the contents of the container.

[0061] Outer edge of the at least one larger or main opening or cut-out 40 has a generally circular shaped edge to conform with an external circumference of the jar 10; and a portion of its inner edge 43 is straight or has less curvature that its circular edge 44.

[0062] The smaller openings 42A, 42B, 42C individually have an area which is less than 15%, more preferably less than 10% and most preferably less than 5% of the area of the larger first opening or cut-out 40. The diameters of the smaller of smaller second openings 42A, 42B, 42C are preferably less than 20% of the size of the radial width of the larger first opening or cut-out 40; preferably the diameters are less than 10% and preferably less than 5% of the radial width of the larger first opening or cut-out 40.

[0063] Referring to Figure 3, there is shown a view of the jar 10, with the wad 20 heat or pressure sealed thereto. Removable metal cap 50 is shown ready for screwing onto the thread 35 of the jar 10. Figure 3 shows that once the wad 20 is heat or pressure sealed onto the top of the jar 10 sealing its contents (not shown) therein, the removable metal cap may be placed on the jar 10. Optionally when this occurs, the removable metal cap may be used to seal the wad 20 around the rim 32 of the jar 10 by way of a compression seal.

[0064] This process may be performed with the wad 20 retained in the removable metal cap 50 prior to the heat or pressure sealing through the effect of being retained by the threaded part 35 of the removable metal cap (formed in circular lateral wall of the removable metal cap 50) or for example by a threaded portion (3) and / or one or more protrusions, beads or ridges (not shown) formed or placed on an inside surface of the circular lateral wall of the removable metal cap 50. The removable metal cap 50 may include means to temporarily retain the wad prior to it being deployed to seal the jar and after the removable metal cap is removed.

[0065] The invention therefore permits either heat and compression adhesion of the wad 20 to the jar and enables the removable metal cap 50 to be press fitted to the jar 10 or to be screwed onto the jar 10 when fitted with a corresponding external thread on its top portion.

[0066] Ideally the wad 20 has a layer of pressure sensitive adhesive or heat activated glue, (not shown) applied in the form of a ring to an underside of its periphery. Established pressure or heat sealing processes may then be used to seal the wad 20 onto the jar 10 after its contents have been added. Specifically, the wad 20 is sealed to the circumference of the container by existing process machinery.

[0067] Figure 3 shows the jar 10 with the wad 20 sealed onto its open end 30. The larger opening orifice 40 is for dispensing larger amount of the contents of the jar when filled and the smaller second openings 42A, 42B, 42C can be used so as to sprinkle smaller amounts of contents from the container. As the wad 20 is adhered around its edge, it can also be removed by the consumer so that the contents of the jar 10 can be emptied in one shot for transfer, or so as to access to the jar with a spatula or spoon in order to spoon the contents. For clarity the contents of the container are not shown in the Figures.

[0068] Figure 4 shows an overall view of the jar in Figure 3, with a liner 51 sandwiched between the wad 20 and the removable metal cap 50. The liner 51 with the wad 20 together define two layers that are separable one from another when the removable metal cap 50 is first removed. The liner 51 may be a card or cardboard with a suitable coating or a polymer. The wad 20 forms a bottom layer which may be foil, such as a metal foil or a polymer foil. When the jar 10 is opened the wad 20 and liner 51 can separate; with the upper liner 51 being retained within the removable metal cap 50, and the bottom portion of the wad 20 still forming a cover on the container to retain the contents of the container.

[0069] Figure 4 shows the container with the removable metal cap 50 fitted to it; that is to say once the removable metal cap 50 is pressed on or screwed down / torqued down to the jar 10 to create a sealed edge between the top of the container 10 and an underside rim of the wad 20 by sandwiching the wad 20 either directly against an inner surface of the underside of the removable metal cap 50; or against a liner 51 itself held against an inner surface of the underside of the removable metal cap 50. It should be noted that the portion of the removable metal cap 50 is shown for illustration purposes and is shown as a schematic representation, as a part-sectional view, fitted to the jar 10 and with a seal created between a top edge of the mouth of the jar and an underside rim portion of the wad 20.

[0070] Reference herein to the term ‘size’, unless indicated otherwise should be interpreted as area of an opening. The term ‘sealed’ in relation to the wad being sealed to the container or receptacle, unless otherwise indicated, should be understood as forming a seal at the, or with the circumference of the open end of the container or receptacle and that such a seal may be temporary, for example if a user choses to remove the wad.

[0071] Figures 5A and 5B show overall and exploded views of a section through the removable metal cap 50 and the location of one example of a retaining means 36 which is formed by pinching or pressing or knurling the removable metal cap 50. In Figure 5B the retaining means 36 is formed by a series of beads or indentations defined around an inner surface of the removable metal cap 50 by the knurls 38 which are on the outside of the removable metal cap 50 to provide grip when unscrewing and tightening the removable metal cap 50.

[0072] When the removable metal cap 50 is deformed to form the knurls 38, a series of indentations appear on an inside surface of the removable metal cap 50. These are shown in Figure 5B as a series of undulations or ledges which extend around an inside surface of the removable metal cap 50. These undulations or ledges clip and hold the liner 51 and acts as the retaining means 36 which hold the liner within the removable metal cap 50 when the removable metal cap 50 is removed from the container 10. Therefore, the retaining means 36 is at least partly defined by knurling 38 formed on the removable metal cap 50.

[0073] It will be appreciated that variation to the aforementioned embodiments may be made without departing from the scope of protection as defined by the claims.

[0074] For example, the removable metal cap may be formed from 0.28mm + / - 15% gauge aluminium or from 0.21 mm + / - 15% gauge tin plated steel

Claims

Claims1 . A removable metal cap (50) and a wad (20) for fitting to a mouth (30) of a container (10), around an edge of one side the wad (20) there is an adhesive layer which adheres an edge of one side of the wad (20) to a rim (32) of the container (10), a liner (51 ) covers the wad (20) and is retained in the removable metal cap (50) to provide long term sealing in use, the liner (51 ) is adapted to separate from the wad (20) to reveal at least one shaped opening (40) formed in the wad (20) and the liner (51 ) is retained in the removable metal cap (50), when the removable metal cap (50) is first unscrewed, by a retaining means (36) within the removable metal cap (50).

2. A removable metal cap (50) with the retaining means (36) to retain a liner (51 ) within the removable metal cap (50) wherein the liner (51 ) covers a wad (20) that is fitted to a mouth of a container (10), the wad (20) has an adhesive layer which adheres an edge of one side of the wad (20) to a rim (32) of the container (10) and a temporary attachment on its other side which attaches the wad (20) to the liner (51 ) until the removable metal cap (50) is first unscrewed, when the liner (51 ) is retained in the removable metal cap (50) by the retaining means (36), and separates from the wad (20), to reveal at least one shaped opening (40) formed in the wad (20), and the liner (51 ) is retained in the removable metal cap (50) to provide long term sealing of the container (10) by the removable metal cap (50) in use.

3. A removable metal cap (50) according to claim 1 or 2 wherein the wad (20) has openings (40, 42) of different sizes.

4. A removable metal cap (50) according to claim 3 wherein the shaped openings comprise at least one larger first opening (40) and a plurality of smaller second openings (42A, 42B, 42C).

5. A removable metal cap (50) according to claim 4 wherein the plurality of second openings (42A, 42B, 42C) is of the same size.

6. A removable metal cap (50) according to claim 4 wherein the plurality of second openings (42A, 42B, 42C) is of the same shape.

7. A removable metal cap (50) according to claim 6 wherein each of the second openings (42A, 42B, 42C) is substantially circular.

8. A removable metal cap (50) according to any of claims 4 to 7 wherein the area of the larger first opening (40) exceeds the combined area of the smaller second openings (42A, 42B, 42C).

9. A removable metal cap (50) according to claim 8 wherein the combined area of the second openings (42A, 42B, 42C) is less than 20%, preferably less than 15%, and more preferably less than 10% of the area of the larger first opening (40).

10. A removable metal cap (50) according to any of claims 4 to 9 wherein the smaller second openings (42A, 42B, 42C) are circular and have diameter which is preferably less than 25% of the diameter of the mouth (30) of the container (10), more preferably less than 10% of the diameter of the mouth (30) of the container (10) and most preferably less than 5% of the diameter of the mouth (30) of the container (10).

11. A removable metal cap (50) according to any of claims 4 to 10 wherein the larger first opening is in the shape of a circular segment, disc segment or crescent shaped.

12. A removable metal cap (50) according to any of claims 4 to 11 wherein one or more openings (42A, 42B, 42C) is shaped or are arranged in the form of a brand or logo or to represent the contents of the container (10).

13. A removable metal cap (50) according to any preceding claim wherein the wad (20) has a heat sealant or pressure sensitive glue coated on at least a portion of one of its surfaces.

14. A removable metal cap (50) according to any preceding claim wherein the wad (20) is circular.

15. A removable metal cap (50) according to any preceding claim wherein the retaining means (36) to retain the liner (51 ) comprises a threaded portion and / or one or more protrusions, beads or ridges (36) on an inside wall of the cap (50).

16. A removable metal cap (50) according to any preceding claim formed from 0.28mm + / - 15% gauge aluminium.

17. A removable metal cap (50) according to any of claims 1 to 15 formed from 0.21 mm + / - gauge tin plated steel.

18. A removable metal cap (50) according to any preceding claim wherein the retaining means (36) is at least partly defined by knurling (38) formed on the removable metal cap (50).

19. A method of fitting a removable metal cap (50) with a liner (51 ) and a wad (20) therewithin, to a container (10), the removable metal cap (50) has a retaining means (36) to retain the liner (51 ) which is temporarily attached to the wad (20); and bonding an edge of one side of the wad (20), by way of an adhesive layer, to a rim (32) of the container (10).

20. A method of fitting a removable metal cap (50) with a liner (51 ) retained therewithin to a mouth of a container (10) which has a wad (20) attached thereto, the removable metal cap (50) has a retaining means (36) to retain the liner (51 ), whereby when the removable metal cap (50) is fitted to the container (10) the liner (51 ) is temporarily attached to the wad (20).21 . A method of fitting a removable metal cap (50) to a mouth of a container (10) which has a liner (51 ) and a wad (20) attached thereto, the removable metal cap (50) has a retaining means (36) to retain the liner (51 ), whereby when the removable metal cap (50) is fitted to the container (10) the liner (51 ) is temporarily attached to the wad (20).

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