REMOVABLE CAP

Abstract

This invention relates to a removable cap which is metallic to facilitate recovery and recycling.

The removable metal cap is for a container, such as tin or jar which may contain supplements or foodstuffs.

The metallic removable cap has a thread for screwing the metal cap onto a threaded opening of a container. A retaining bead is provided on its inner surface and retains a two-piece wad. The two-piece wad is formed from an upper (cap) layer and a lower (container) layer.

When installed the lower layer seals the container and the retaining bead retains the two-piece wad until removal of the metal cap from the container whereupon the upper layer of the wad separates from the lower layer of the wad and is held inside the metal cap by the retaining bead.

Claims

1. A metal removable cap (10) has a thread for screwing the metal cap (10) onto a threaded opening of a container, such as a tin or jar; a retaining bead (14); and a two-part wad (12) formed from an upper (cap) layer and a bottom (container) layer, wherein when installed the bottom layer seals the container the retaining bead retains the two-part wad (12) until removal of the metal cap (10) from the container whereupon upper layer (12A) of the two-part wad (12) separates from the bottom layer (12B) of the two-part wad (12) and the upper layer of the two-part wad is held inside the metal cap (10) by the retaining bead (14).

2. A removable cap according to claim 1 wherein the threaded portion (33) has a pitch to match a mouth of a specified container (20), such as a tin or jar.

3. A removable cap as according to claim 1 wherein the upper layer (12A) comprises a substantially organic material, such as a carboard or a paper-based layer.

4. A removable cap according to claim 1 wherein the bottom layer (12B) comprises a sealing membrane which seals the opening of the container (20).

5. A removable cap according to claim 4 wherein the sealing membrane comprises a wax layer.

6. A removable cap according to claim 1 wherein the retaining bead (14) is dimensioned and arranged to retain the upper layer (12A) within the metal cap (10) after the metal cap is removed from the container (20).

7. A removable cap according to claim 1 wherein the retaining bead (14) comprises one or more protrusions formed on an inside surface of the metal cap.

8. A removable cap according to claim 1 wherein the retaining bead (14) comprises one or more pips on an inside surface of the metal cap.

9. A removable cap according to claim 1 wherein the retaining bead (14) comprises one or more ridges on an inside surface of the metal cap.

10. A removable cap according to claim 1 wherein the two-part wad (12) includes a metallic or polymer wad.

11. A combination of a container (20) and a metal removable cap (10) according to claim 1 when fitted to a container which is formed from glass.

12. A combination of container (20) and a metal removable cap (10) according to claim 1 when fitted to a container which is formed from a synthetic plastic material.

13. A method of fitting a removable metal cap (10) to a filled container (20) comprising the steps of: providing a container (20) having an open end, adding contents to the container, providing a two-part wad (12) with a seal within the metal cap (10), placing the metal cap (10) over the open end of the container, closing the metal cap on the container and heat sealing the seal to form a tamper evident layer over the open end of the container.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] FIG. 1 shows an example of a cap fitted to a jar according to one example of the invention;

[0036] FIG. 2A shows a diagrammatical section of a jar with a metal cap fitted thereto;

[0037] FIG. 2B shows an exploded view of the metal cap and in detail a wad retaining bead in diagrammatical section;

[0038] FIGS. 3A to 3D show an overall view of a jar (FIG. 3B) with a heat-sealed layer and a cap (FIG. 3D) removed in readiness for replacement on the jar, FIG. 3A showing enlarged detail of a circled portion in FIG. 3B, and FIG. 3C showing enlarged detail of a circled portion in FIG. 3D;

[0039] FIG. 4 shows how the removable metal cap and container appear to a consumer when the container is opened for the first time with its tamper evident seal intact.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENTS OF THE INVENTION

[0040] FIG. 1 illustrates an example of a finished assembly of a removable metal cap 10 screwed onto a jar 20 by its threaded portion 33 (shown in FIG. 3) after heat sealing has fixed a wax layer 30 (FIG. 3) to the jar.

[0041] Referring to FIG. 2A there is shown a diagrammatical section of the jar 20 with the removable metal cap 10 fitted thereto. The jar 20 is open ended with a circular rim 22 at its open end and has a screw thread for receiving the removable metal cap 10. However, in other examples the rim 22 may take alternative forms.

[0042] FIG. 2B shows a two-part wad 12 is retained in the removable metal cap 10 by a retaining bead 14. A two-part wad 12 has an upper layer 12A and a lower or bottom layer 12B, described in detail below, and is of a shape which generally conforms to the shape of an open end of the container 20.

[0043] The two-part wad 12 preferably comprises two layers, an upper layer 12A and a bottom layer 12B. Bottom layer 12B may typically be formed as metal foil or a polymer foil and is of a suitable diameter to fit around and adhere to the circular rim 22. When the jar 10 is opened the layers 12A and 12B separate the upper layer 12A is retained within an upper part of the metal cap 10 by the bead 14. The bottom layer 12B, and any foil or polymer portion formed thereon, forms a seal, such as a tamper evident seal, 24 which adheres around the circular rim 22 of the container 20 to seal its contents (not shown).

[0044] A heat-sealing or gluing process is used to seal the bottom layer 12B of the two-part wad 12 onto the jar 20, after contents, such as coffee granules (not shown) have been added to the jar 20. Specifically, the two-part wad 12 is sealed to the circumference or circular rim 22 of the container or jar 20. Furthermore, the two-part wad 12 can be removed by a consumer so that the contents of the jar 20 can be emptied in one shot for transfer, or to allow access to the jar 20 so that its contents can be removed with a spatula or spoon. For clarity the contents of the jar 20 are not shown in the Figures.

[0045] FIG. 4 shows what is seen when the removable metal cap 10 is first removed by a consumer. The foil part of the bottom layer 12B of the two-part wad 12 separates from the upper cardboard layer 12A, when the metal cap 10 is first unscrewed. The foil part of the bottom layer 12B is shown sealed to an upper mouth of the jar 20. The cardboard layer 12A of the two-part wad 12 snaps or tears and is retained behind the retaining bead 14 within the removable metal cap 10. FIG. 4 therefore shows how tamper evident seal 24 covers the container 20 and protects its contents. The tamper evident seal 24 of the two-part wad 12 is heat sealed (to the jar 20 with its contents inside) soon after filling of the jar 20.

[0046] It will be appreciated that the metal cap 10 may be supplied with the two-part wad 12 in situ or the two-part wad 12 may be inserted or fitted to, or forced into, the removable metal cap 10 prior to sealing the jar or container 20.

[0047] The removable metal cap 10 may be placed on the jar such that the removable metal cap 10 and seal 24 and are pulled down or compressed onto the top face of the container 20. This process may be performed with a liner fitted to the removable metal cap 10 prior to the heat sealing.

[0048] It will be appreciated that in the embodiments described above that one advantage of the invention is that no modification of any existing manufacturing processes or equipment or filling processes is needed.

[0049] The removable metal cap 10 may be press fitted to the jar 20 or it may be screwed onto the jar 20 which is rotatably fitted with a corresponding external thread 33 on a top portion of the container.

[0050] The metal cap 10 includes means to retain the upper wad layer within the metal cap after the metal cap is removed. The means to retains comprises one or more protrusions or retaining beads 14. It will be appreciated that the retaining bead 14 may consist of ridges or pips on an inside wall of the metal cap. FIG. 2B shows in section and in greater detail, the two-part wad retaining bead(s)/protrusions 14.

[0051] Alternatively, an internal ridge/shelf may be provided for this purpose-which may be circular or part circular in form. This is effectively a circumferential ridge which allows retention of the cardboard upper later of the two-part wad within the metal cap when the metal cap is removed. So, the metal cap includes means to retain the upper wad layer 12A which remains therewithin, even after the metal cap 10 is removed; this may be via one or more protrusions, beads or ridges 14 on an inside wall of the metal cap. In other embodiments an adhesive may applied to the inside surface of the removable metal cap 10 to retain the upper lay when opened.

[0052] Referring to FIGS. 3A to 3D, the retaining bead 14 in FIG. 2B and in particular the item bead profile shown in the exploded view. In the embodiment shown the distance between the top of the retaining bead 14 and an underside of the top of the cap is 2.5 mm and this is typically subject to a tolerance of 20%. Ideally the bead profile has a flat top when orientated with respect to an inside surface of the top of the removable cap 10 and a fixed radius (r) with a sloping profile (), where a is typically 40. Again, the tolerance to the radius (r) and sloping profile () are both subject to a tolerance of 20%.

[0053] FIG. 4 shows how the removable metal cap assembly appears to a consumer when the container is opened for the first time. The lower foil layer or bottom layer 12B of the two-part wad stays sealed to the jar. The cardboard upper layer snaps off or is separated from the foil layer and is retained behind the retaining bead formed in the metal cap. FIG. 4 shows that after removal of the cap 10, and prior to first time access to the contents of the container 20, the lower or foil part of the bottom layer 12B of the two-part wad 12 acts as a tamper evident seal 30 and, after it is removed, the upper or cardboard layer 12A of the two-part wad 12 snaps or tears and is retained behind the retaining bead 14 within the removable metal cap 10. Subsequently, upper or cardboard layer 12A repeatedly re-seals the contents of the container 20 due to its resiliently deformable nature, its sealing properties and the fact that the cardboard layer 12A is dimensioned to abut and press against the circular rim 22 of the container 20 and is held tightly against it by metal cap 10.

[0054] The term size unless indicated otherwise should be interpreted as area such as 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, or with, the circumference of the open end of the container.

[0055] It is appreciated that variation may be made to the aforementioned embodiments, without departing from the scope of the invention, as defined by the claims.

List of Parts

[0056] 10 metal cap [0057] 12 two-part wad [0058] 12A upper (or cardboard) layer [0059] 12B bottom (or foil, synthetic plastic film or wax) layer [0060] 14 beads or protrusions [0061] 20 container or jar [0062] 22 circular rim [0063] 24 tamper evident foil or wax paper seal [0064] 30 heat sealing wax layer [0065] 33 external thread