GB2632029A - Overcap - Google Patents

Abstract

A cap for a container having a planar centre panel 32 and a downwardly extending sidewall 40 descending from a peripheral region 33, ending with an inwardly directed curl 42 around the circumference of the sidewall. The curl has collapsed portions (figure 5, 46) and lug portions (figure 5, 48). The container has an outwardly curled edge (figure 7, 52) surrounding the opening. The lug portions may clip over the outwardly curled edge to secure the cap to the container and resist removal. The cap may be metal. There may be a channel (figure 12B, 152) that contains a sealing compound. The container may have an inwardly directed bead (figure 10, 72) extending around the opening for carrying a foil member (figure 10, 70). The foil closes the opening and is in close proximity to the cap. The container may be metal and substantially tubular. To fill the container, first the foil is affixed to the bead and then the cap is attached. Product enters through a bottom opening of the container, which then may be closed by seaming a metal end.

Description

OVERCAP

TECHNICAL FIELD

[0001] The present invention relates to overcaps for closing containers, and more particularly, to overcaps suitable for closing metal containers containing foodstuffs.

BACKGROUND

[0002] It is common for foodstuffs to be packaged within a container, where an overcap is used to seal the container through press fitting the overcap to the container body. Overcaps can also facilitate reclosure of the container after opening, which is important for reducing contamination and maintaining the integrity of the foodstuffs within the container.

[0003] Figures 1A and 1B show two views of a conventional overcap 10 according to present designs. As illustrated, overcaps 10 according to present designs include a circular centre panel 12 and downwardly projecting side walls 14 extending from the peripheral edge of the centre panel 12. The side walls 14 terminate in a curl 16 on the cut edge, where the curl 16 ensures any sharp edges on the cap are avoided, which is important for safety purposes. While the example shown in Figures 1A and 1B includes an outward curl, other conventional overcaps 10 may include an inward curl.

[0004] In order to close a container, conventional overcaps 10 further comprise a plurality of features known as pips 18 pressed into the sidewalls 14, and spaced circumferentially around the side wall 14 between the peripheral edge of the centre panel 12 and the curled edge 16, where the pips 18 extend radially inward towards the centre of the overcap (10). The pips 18 are configured to enable closure of a container with the overcap 10: the overcap 10 is pressed onto the container, and the pips 18 snap beneath an upper curled edge of the container body, thus retaining the overcap 10on the container. The pips 18 are shown in greater detail in Figure 2, which also shows example dimensions for the case where the overcap 10 is a 14 mm diameter overcap [0005] Returning to Figures 1 A and 1B, a stacking feature 20 is also shown as part of the overcap 10. Stacking features 20 are often included as part of conventional overcaps 10 to allow cans to be stacked securely on top of each other for storage. The stacking feature 20 is a step that extends circumferentially around the centre panel 12, giving rise to a circular region of increased height in the centre of the centre panel 12. The distance from the overcap's peripheral edge to the stacking feature 20, and thus the diameter of the region of increased height, can vary, and is dependent on if the container being used with the overcap 10 is necked (i.e. tapers inward at the base) or straight walled.

[0006] There are several limitations of current overcap designs. Firstly, it is of great interest in the packaging industry to reduce waste, and so reducing the amount of material used in an overcap is desirable. In the current designs, there is a limit on how much the overcap material can be reduced due to the need to form two separate features on the overcap side wall: a pip 18 to retain the overcap 10 on the container body, and a separate curl 16 beyond the pip 18 on the cut edge of the side wall 14 to make the cut edge of the overcap safe.

[0007] Secondly, plastic is the material most often used in overcaps, however customers are increasingly looking to reduce their plastic use. There has therefore been a move towards metal overcaps. In current metal overcaps however, the seal performance is decreased significantly compared to plastic, which is a limitation that must be addressed in order for metal to be a viable material for overcaps.

[0008] An objective of the current invention is therefore to overcome some of the limitations described above, and to provide a metal overcap that enables a reduction in the amount of material used, while having a seal performance comparable to that of a plastic overcap.

SUMMARY OF THE INVENTION

[0009] According to a first aspect of the present invention there is provided a closure adapted for use in closing a container body for foodstuffs, the container having an opening defined by an outwardly curled edge, the closure comprising a generally planar centre panel and a downwardly extending sidewall depending from a peripheral region of the centre panel and terminating with an inwardly directed curl around the circumference of the sidewall. The inwardly directed curl comprises collapsed portions where the curl has been collapsed and lug portions where the curl has not been collapsed.

[0010] The lug portions of the inwardly directed curl allow the closure to be easily press-fitted onto the container, and thus it is well-suited for closing and re-opening containers.

[0011] Since a single feature on the closure, the inwardly directed curl comprising lug portions and the collapsed portions, is used to both clip the closure onto a corresponding container and avoid sharp edges on the overcap, the sidewalls of the closure can be shorter, and thus the overcap of the present invention is more material efficient.

[0012] The lug portions may be configured in use to be retained beneath the curled edge of the container to resist removal of the closure when the container body is closed by the closure.

[0013] The radial inward extent of the collapsed portions may be less than the lug portions.

[0014] The inwardly directed curl may comprise three or more lug portions substantially equiangularly spaced around the circumference of the sidewall.

[0015] The closure may be formed from metal.

[0016] The centre panel may comprise an inner disc region, an upwardly extending step and the peripheral region.

[0017] The step may define a channel, the channel being filled with a sealing compound.

[0018] The sealing compound on the closure allows the metal closure to achieve a moisture barrier performance similar to that of a plastic overcap. This is advantageous as metal closures are becoming more popular as users look to reduce their plastic use [0019] The closure may define a vertical axis and the inner disc region and the peripheral region may be located at different axial positions along the vertical axis.

[0020] The inner disc region may be below the peripheral region.

[0021] The container body may comprise an inwardly directed bead extending circumferentially around the container body adjacent to the opening, the inwardly projecting bead being configured to carry a foil member for closing the opening, and wherein the closure is dimensioned such that the inner disc region closure is in close proximity to the foil when the closure is in use.

[0022] According to a second aspect of the present invention there is provided a container comprising a substantially tubular metal container body having a top opening defined by an outwardly curled edge, and a closure according to the first aspect of the invention, the closure and the container body having relative dimensions to allow the lug portions to pass over said curled edge during closure and to be retained beneath the curled edge to resist removal of the closure.

[0023] The container body may comprise an inwardly directed bead extending circumferentially around the container body adjacent to the top opening, the inwardly projecting bead being configured to carry a foil member for closing the opening, and wherein the closure is dimensioned such that the inner disc region closure is in close proximity to the foil.

[0024] According to a third aspect of the present invention, there is provided a method of filling a container, the method comprising providing a substantially tubular metal container body, the container body comprising a top opening defined by an outwardly curled edge, an inwardly directed bead extending circumferentially around the container body adjacent to the top opening, the inwardly projecting bead being configured to carry a foil member for closing the opening, and a bottom opening. The method further comprises providing a closure having an opening defined by an outwardly curled edge, the closure comprising: a generally planar centre panel and a downwardly extending sidewall depending from a peripheral region of the centre panel and terminating with an inwardly directed curl around the circumference of the sidewall, wherein the inwardly directed curl comprises collapsed portions where the curl has been collapsed and lug portions where the curl has not been collapsed, the closure and the container body having relative dimensions to allow the lug portions to pass over said curled edge during closure and to be retained beneath the curled edge to resist removal of the closure and wherein the closure is dimensioned such that the inner disc region closure is in close proximity to the foil. The method additionally comprises: providing the foil member; affixing the foil member to the inwardly directed bead; attaching the closure to the container body at the top opening such that the lug portions pass over the curled edge and are retained beneath the curled edge; and filling the container through the bottom opening, wherein the centre panel of the closure is configured to support the foil member during filling to prevent the foil member from detaching from the inwardly directed bead.

[0025] The closure being dimensioned such that the inner disc region closure is in close proximity to the foil means that during filling, when the container is inverted and product is filled from the open base, the inner disc region can support the foil as it deforms due to the weight of the product inserted into the container. Additionally, this feature is useful in post-filling processes where a force is applied to the product to remove air gaps, which also causes the foil to deform towards the inner disc region.

[0026] The method may additionally comprise providing a metal end and seaming the metal end to the bottom opening to close the bottom opening in a substantially airtight manner.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1A is an isometric view of an overcap according to a prior art design; [0028] Figure 1B is a cross-sectional view showing a portion of the overcap of Figure 1A; [0029] Figure 2 shows details of the pips, and overcap dimensions for the overcap of Figure 1A, where the overcap is a 14 mm diameter overcap; [0030] Figure 3A is an isometric view of an overcap according to an embodiment of the present invention; [0031] Figure 3B is a cross-sectional view of a portion of the overcap of Figure 3A; [0032] Figure 4 is a cross-sectional view of the overcap of Figure 3B, showing dimensions for a 77 mm diameter overcap; [0033] Figure 5 is a cross-sectional view showing the inward curl of Figure 3A in greater detail, and a collapsed curl region; [0034] Figures 6A is a isometric view of the upturned overcap of Figure 3A; [0035] Figure 6B is a plan view of the upturned overcap of Figure 3A; [0036] Figure 7 is a cross-sectional view of the overcap of Figure 3B interacting with two containers; [0037] Figure 8A is an isometric view of an overcap according to a further embodiment of the present invention; [0038] Figure 8B is a cross-sectional view showing a portion of the overcap of Figure 8A; [0039] Figure 9 is a cross-sectional view of the overcap of Figure 8A, showing dimensions for a 77 mm diameter overcap; [0040] Figure 10 is a cross-sectional view of the overcap of Figure 8A interacting with a container; [0041] Figure 11 is a cross-sectional view of the overcap of Figure 8A interacting with two containers; [0042] Figure 12A is an isometric view of an overcap according to an additional embodiment of the present invention; [0043] Figure 12B is a cross-sectional view showing a portion of the overcap of Figure 12A; [0044] Figure 13 is a cross-sectional view of the overcap of Figure 12A, showing dimensions for a 77 mm diameter overcap; and [0045] Figure 14 is a cross-sectional view of the overcap of Figure 12A interacting with two containers.

[0046] DETAILED DESCRIPTION

[0047] Metal overcaps in accordance with embodiments of the present invention are described below in relation to Figures 3 to 14.

[0048] Figure 3A shows a perspective view of an overcap 30 in accordance with an embodiment of the present invention, where the overcap 30 includes a substantially flat centre panel 32 comprising an inner disc region 35 with an upper surface 44a and a lower surface 44b, a peripheral region 33, and an upwardly extending step 34 extending circumferentially around the inner disc region 35 (shown in more detail in Figure 4). The step 34 divides the inner disc region 35 and the peripheral region 33 of the centre panel 32, and defines a stacking feature for securely stacking containers on top of the overcap 30. The radial distance 36 from the outer edge of the peripheral region 33 to the step 34 is determined by the container the overcap 30 is being used with.

[0049] A cross-sectional view of a portion of the overcap 30 is shown in Figure 3B. An inward inclined wall 38 surrounds the inner disc region 35 of the centre panel 32 and extends from the inner disc region 35 to the step 34, so that the step 34 has a height above the inner disc region 35, for example, of approximately 1.5 mm. The height of the step 34 above the inner disc region 35 can be varied to elicit different advantages (discussed later). The overcap 30 additionally comprises downwardly projecting side walls 40 extending from the peripheral region 33 of the centre panel 32 and terminating in an inwardly directed curl 42, where the inwardly directed curl 42 extends circumferentially around the bottom, cut edge of the overcap 30.

[0050] Figure 4 shows the overcap 30 of Figure 3B, specifying example dimensions for the case where the diameter of the overcap 30 is 77 mm (which is designed to fit a standard 73 mm container). While an embodiment describing a 77 mm overcap is shown in detail, overcaps with different diameters are possible, and in these other embodiments, dimensions of individual features are scaled accordingly. As illustrated in Figure 4, the diameter of the overcap 30 is 77.4 mm and the total height of the overcap 30 is 5 mm. The inward inclined wall 38 extends at an angle of 43 degrees from the inner disc region 35 of the centre panel 32 to the upwardly extending step 34, so that the step 34 has a height of 1.5 mm above the upper surface 44a of the inner disc region 35, and a height of 1 mm above the peripheral region 33 of the overcap 30. While an angle of 43 degrees is shown in this embodiment, different angles can be used in other embodiments. The inwardly directed curl 42 at the cut edge of the side walls 40 has a radius of 0.75 mm. The diameter of the inwardly directed curl 42 is dependent on the container the overcap 30 is being used with, as it is this feature that interferes with the container body to retain the overcap 30 on the container.

[0051] Figure 5 shows a portion of the inwardly directed curl 42 of the overcap 30 in greater detail. Portions of the inwardly directed curl 42 are collapsed 46, and portions of the inwardly directed curl 42 which are not collapsed are referred to as lug portions 48. The thickness of the lug portions 48 are therefore the diameter of the inwardly directed curl 42, and the collapsed portions 46 have a thickness less than the diameter of the inwardly directed curl 42. For example, in the embodiment shown in Figure 4, where the diameter of the curl 42, and thus the thickness of the lug portions 48, is 1.5 mm, the collapsed portions 46 have a thickness between 0.5 and 0.9 mm. The number of collapsed portions 46 and the number of lug portions 48 on the overcap 30 can be varied, and the number of each is dependent on the size of the overcap 30. The collapsed curl portions 46 can be formed by pressing the inwardly directed curl 42 inwards.

[0052] Figures 6A and 6B show an isometric view and a plan view of the upturned overcap 30, where four lugs 48 and four collapsed curl portions 46 can be seen evenly spaced around the circumference of the overcap 30. The lugs 48 are configured to interfere with a seamed upper edge 52 of a container 50 body to clip' the overcap 30 onto the container 50, while the collapsed curl portions 46 allow the overcap 30 to be easily press-fitted onto the container 50. If the inwardly directed cud 42 was not collapsed in any regions, the force required to remove the overcap 30 would be extremely high, and the overcap 30 would not be suitable for closing and re-opening containers. While Figures 6A and 6B show an overcap 30 with 4 lugs 48, the number of lugs 48 may be varied depending on the diameter of the overcap 30. For example, in the embodiment of Figure 4, where the diameter of the overcap 30 is 77 mm, four lugs 48 are sufficient to retain the overcap 30 on the container 50 body, however in other embodiments where the diameter of the overcap 30 is increased, more lugs 48 will be required. It should be noted that preferably a minimum of three lugs 48 are required no matter the diameter of the overcap 30, in order for the overcap to close a container.

[0053] Figure 7 shows an example of an overcap 30 sealing a first container body 50a, and stacked with a second container body 50b, where only a seamed upper edge 52 of the first container body 50a, and a seamed end 54 of the second container body 50b are included for the reader's clarity. When the overcap 30 is press fitted onto the first container body 50a, the inwardly directed curl 42 of the overcap 30 (specifically the lug portions 48) creates an interference fit with the seamed upper edge 52 of the first container body 50a, which retains the overcap 30 on the container body 50a. In order to create the interference fit, the diameter of the inwardly directed curl 42 of the overcap 30 is between 0.1 mm and 0.7 mm smaller than the maximum outside seam diameter of the container 50a.

[0054] Figure 7 also shows the seamed end 54 of the second container body 50b, stacked on top of the overcap 30. In this embodiment, the seamed end 54 of the container body 50b sits outwards of the step 34, and the inclusion of the step 34 ensures stability of the container 50b when stacked on top of the overcap 30. In other embodiments, the stacking feature 34 can be offset by up to 3 mm towards the peripheral region 35 of the overcap 30, and the seamed end 54 can sit inwards of the step 34.

[0055] An advantage of this overcap compared with the prior art designs discussed previously with reference to Figures 1 and 2, is that instead of requiring two separate features, pips 18 and an inward curl 16, to clip the overcap onto the container and to avoid sharp edges on the overcap, a single feature is able to carry out both functions. Accordingly, the side walls 40 of the overcap 30 of the present invention can be much shorter, and therefore are more material efficient than standard overcaps. For example, the total height of a conventional 14 mm diameter overcap is approximately 9.3 mm (as shown in Figure 2), while the total height of an overcap 30 according to the present invention is 5 mm (as shown in Figure 4). Therefore, the amount of material used to create an overcap according to the present invention is reduced, and only 89% of the material used to create a conventional 14 mm diameter overcap is required.

[0056] In some embodiments, the overcap 30 is configured to support a peelable lid on a corresponding container. In containers containing foodstuffs, a peelable lid is often included in order to protect the contents of the container from contamination. While a peelable foil lid is described here, it is noted that the peelable lid may be made of other suitable materials including paper, cardboard, and plastics, or any combination of these.

[0057] An overcap 30 according to an embodiment configured to provide support for a peelable foil lid on a container is shown in Figures 8A and 8B. Figure 8A shows a perspective/isometric view of the overcap 30, and Figure 8B shows a cross-sectional view of a portion of the overcap 30. Similar to the embodiment described in Figures 3 to 7, the overcap 30 comprises a centre panel 32 that includes an inner disc region 35 (with an upper surface 44a and a lower surface 44b), an upwardly extending step 34, and a peripheral region 33. The overcap 30 additionally has downwardly projecting side walls 40 extending from the edge of the peripheral region 33 of the overcap 40 and terminating in an inwardly directed curl 42. Although not shown in Figures 8A and 8B, the inwardly directed curl 42 is collapsed in multiple locations spaced circumferentially around the overcap 30 which gives rise to lug portions 48, which act to clip onto the seamed upper edge 52 of a container 50 and thus retain the overcap 30 on a container/can 50 body, in the same manner as previously described with reference to Figures 6A, 6B, and 7.

[0058] In order to support a peelable foil lid, the vertical distance between the upwardly extending step 34 and the upper surface 44a of the inner disc region 35 is increased as compared to the previous embodiment. As illustrated in Figure 8B, the overcap 30 comprises inward inclined walls 38 surrounding the inner disc region 35 and extending between the inner disc region 35 and the step 34 at an angle close to 90 degrees. This configuration means that the vertical distance between the upper surface 44a of the inner disc region 35 and the step 34 is approximately equal to the vertical distance between the uppermost surface of the inwardly directed curl 42 and the step 34. Accordingly, the step 34 has an increased height above the inner disc region 35, but the height of the step 34 above the peripheral region 33 of the overcap 30 is unchanged compared with the embodiment described in Figures 3 to 7.

[0059] The overcap 30 of Figure 8B is shown in greater detail in Figure 9, which shows the overcap 30 with dimensions according to a 77 mm diameter overcap. In this embodiment, the step 34 has a height of approximately 3.7 mm above the upper surface 44a of the inner disc region 35, while the height of the step 34 above the peripheral region 33 of the overcap 30 remains at 1 mm.

[0060] An example of the overcap 30 press-fitted to a container 50 with a peelable foil lid 70 is illustrated in Figure 10. The container 50 has a seamed upper edge 52 (closed curl) defining a top opening into the body, where the seamed upper edge 52 lies radially outside of the container body 50. The container body 50 also comprises an inwardly directed bead 72 extending circumferentially around the body adjacent to the top opening. A peripheral and circumferential region (outer edge) of the foil lid 70 is bonded to an upper surface of the inwardly directed bead 72. It will be appreciated that due to the seamed upper edge 52 acting as a rim above the peelable foil lid 70, no part of the overcap 30 makes contact with the foil lid 70 during closure or opening, and thus there is no risk of the lid 70 being damaged during this process.

[0061] The interference fit of the lug portions 48 on the overcap 30 with the upper seamed edge 52 of the container body 50 seals the container 50, in the same manner previously discussed with reference to Figures 6A, 6B, and 7. During closure the lower surface 44b of the centre panel 32 lies above the peelable foil lid 70, with only a small vertical distance between the two surfaces.

[0062] This feature is useful in filling processes whereby the product is filled from the open base of a sealed container 50 whilst the container 50 is inverted. In this case, product is dropped onto the foil 70 causing the foil 70 to deform and bend towards the lower surface 44b of the inner disc region 35, thereby making contact with the lower surface 44b of the inner disc region 35. When in contact with the foil 70, the centre panel 32 of the overcap 30 supports the foil 70, ensuring that it is not inadvertently peeled off the container 50 during the filling process.

[0063] Additionally, sometimes after filling the container 50 from the base a force is applied directly to the product to remove any air gaps and ensure that the volume of the container 50 not taken up by product (the headspace) is correct and in line with the container's specification. Applying a force to the product also causes the foil 70 to deform and contact the lower surface 44b of the inner disc region 35, and so the centre panel 32 again supports the foil lid 70, ensuring it is not removed during the filling process [0064] Figure 11 shows the overcap 30 configured to support a peelable foil lid 70 press-fitted to a first container body 50a, with a second container 50b stacked on top of the overcap. The seamed end 54 of the container 50b sits outwards of the step 34 but, as discussed previously with reference to Figure 7, the upwardly extending step 34 may be offset: in the embodiment described in Figures 8 to 11, the step can be offset. by up to 3 mm towards the centre of the overcap 30, . [0065] Again, in this embodiment the amount of material in the overcap is decreased compared to prior art designs, with the overcap 30 configured to support a peelable lid 70 containing 93% of the material of a 14 mm conventional overcap. As such, the overcap 30 in accordance with the present embodiment is more material efficient.

[0066] Figures 12 to 14 illustrate an alternative overcap 130 construction, where a compound is added to the overcap 130 to improve the sealing performance. Figures 12A and 12B show two views of an overcap 130, comprising a centre panel 132 with an inner disc region 135 and a step 134, where inward inclined walls 138 extend between the inner disc region 135 and the step 134. The step 134 defines a stacking feature, which provides stability for stacking containers on top of the overcap 130.The overcap 130 additionally comprises downwardly projecting side walls 140 depending from the step 134 and terminating in an inwardly directed curl 142. Although not shown in Figures 12A and 12B, the overcap 130 also comprises regions where the inwardly directed curl 142 is collapsed which gives rise to lug portions 48. The closure mechanism, where the lug potions 48 create an interference fit with the seamed upper edge 52 of a container body 50, operates in the same way as described with reference to Figures 6A, 6B, and 7.

[0067] As illustrated in Figure 12B, the outer surface of the side wall 140 of the overcap 130 comprises a concave portion 150, where the radius of the concave portion may be, for example, 0.8 mm. The space between the inner surface of the step 134 and the inner surface of the concave portion 150 of the side wall 140 define a compound channel 152, into which a sealing compound is spun. The sealing compound may be, for example Artiseal 2630, but any other suitable compound may be used. In the spinning process, the overcap 130 is inverted and rotated at high speed. The sealing compound is injected into the compound channel 152, and the rotation of the overcap 130 drives the compound to move down the inner surface of the sidewalls 140 of the overcap 130, thus coating the inner surface of the side walls 140. Spinning is used to add the sealing compound to the overcap 130 as it is a highly efficient method, and because the same equipment can be used for overcaps of different sizes. During closure of a container 50 with the overcap 130 the compound is in sealing engagement with the container 50, and thus the seal of the overcap 130 to the container 50 is improved.

[0068] Figure 13 shows the cross-sectional view of the overcap 130 of Figure 12B in greater detail, with dimensions corresponding to a 77 mm diameter overcap. For overcaps of different sizes, the individual dimensions are scaled accordingly. The inward inclined walls 138 extend from the inner disc region 135 at an angle of 20 degrees to the step 134. The downwardly projecting side walls 140 extend from the step 134, and include a concave portion 150 with radius 0.8 mm. The side walls 140 terminate with an inwardly directed curl 142 with radius 0.75 mm. The total height of the overcap 130 of the present embodiment is 4.10 mm, however this height can range from 4.05 mm to 4.25 mm. The height of the overcap is decreased compared to the previous embodiments, and as such less material is used. Indeed, in the present embodiment containing the compound channel 152, the total material used to manufacture the overcap is 87% of the material required to manufacture a conventional overcap. As such, the overcap 130 according to the present embodiment is more material efficient than prior art designs.

[0069] Prior to sealing a container 50 with the overcap 130, a sealing material is spun into the compound channel 152. Due to the profile of the cap 130, during spinning the sealing material runs up the inner surface of the side wall 140 to the concave portion 150, and the sealing material coats the inner surface of the step 134 and the inner surface of the concave portion 150. These are the locations the upper seamed edge 52 of the container 50 will be in direct contact with during closure, which is illustrated in Figure 14. A compound feature is formed that wraps around the top and side of the seamed upper edge 52, and acts to better seal the overcap 130 onto the container body 50. Including the sealing material in the compound channel 152 allows the overcap 130 to achieve a moisture barrier performance similar to that of a plastic overcap, therefore overcoming the reduced sealing performance previously associated with metal overcaps.

[0070] Figure 14 shows the overcap 130 of Figures 12 and 14 interacting with two containers 50a, 50b, where the seamed upper edge 52 of the first container 50a and the seamed end 54 of the second container 50b are shown. In the illustrated embodiment, the lugs 48 on the inwardly directed curl 142 of the overcap 130 interfere with the upper seamed edge 52 of the first container 50a to create an interference fit and retain the overcap 130 on the can body. Again, the diameter of the inwardly directed curl 142 of the overcap 130 is between 0.1 mm and 0.7mm smaller than the maximum outside seam diameter of the container 50. The upper radius 160 of the seamed upper edge 52 is in direct contact with the sealing material in the compound channel 152. Thus, there is an improved seal between the container body 50a and the overcap 130.

[0071] The second container 50b in Figure 14 is shown stacked on top of the overcap 130. In this embodiment the seamed end 54 of the container body 50b sits inboard of the step 134. The upper seamed edge 52 of the container 50a fits in the compound channel 152, and as the step 134 defines the compound channel 152, the step 134 cannot be offset in this embodiment. The seamed end 54 of the second container 50b always sits inboard of the step when a container 50 is stacked on top of the overcap 130.

[0072] It will be appreciated by the person skilled in the art that various modifications may be made to the above described embodiment, for example modifications to the number of lugs 48 and the height of the overcap 130, without departing from the scope of the present invention.

Claims (14)

1. CLAIMS1. A closure for use in closing a container body having an opening defined by an outwardly curled edge, the closure comprising: a generally planar centre panel; and a downwardly extending sidewall depending from a peripheral region of the centre panel and terminating with an inwardly directed curl around the circumference of the sidewall, wherein the inwardly directed curl comprises collapsed portions where the curl has been collapsed and lug portions where the curl has not been collapsed.
2. 2. A closure as claimed in Claim 1, where the lug portions are configured in use to be retained beneath the curled edge of the container to resist removal of the closure when the container body is closed by the closure.
3. 3. A closure as claimed in Claim 1, wherein the radial inward extent of the collapsed portions is less than the lug portions.
4. 4. A closure as claimed in any preceding claim, wherein the inwardly directed curl comprises three or more lug portions substantially equi-angularly spaced around the circumference of the sidewall.
5. A closure as claimed in any preceding claim, wherein the closure is formed from metal.
6. 6. A closure as claimed in any preceding claim, wherein the centre panel comprises an inner disc region, an upwardly extending step and the peripheral region.
7. 7. A closure as claimed in Claim 6, wherein the step defines a channel, the channel being filled with a sealing compound.
8. 8. A closure as claimed in Claim 65 or 7, wherein the closure defines a vertical axis and the inner disc region and peripheral region are located at different axial positions along the vertical axis.
9. 9. A closure as claimed in Claim 8, wherein the inner disc region is below the peripheral region.
10. 10. A closure as claimed in Claim 9, wherein the container body comprises an inwardly directed bead extending circumferentially around the container body adjacent to the opening, the inwardly projecting bead being configured to carry a foil member for closing the opening, and wherein the closure is dimensioned such that the inner disc region closure is in close proximity to the foil when the closure is in use.
11. 11. A container comprising: a substantially tubular metal container body having a top opening defined by an outwardly curled edge; a closure as claimed in any one of Claims 1 to 10, the closure and the container body having relative dimensions to allow the lug portions to pass over said curled edge during closure and to be retained beneath the curled edge to resist removal of the closure.
12. 12. A container as claimed in Claim 11, wherein the container body comprises an inwardly directed bead extending circumferentially around the container body adjacent to the top opening, the inwardly projecting bead being configured to carry a foil member for closing the opening, and wherein the closure is dimensioned such that the inner disc region closure is in close proximity to the foil.
13. 13. A method of filling a container, the method comprising: providing a substantially tubular metal container body, the container body comprising a top opening defined by an outwardly curled edge; an inwardly directed bead extending circumferentially around the container body adjacent to the top opening, the inwardly projecting bead being configured to carry a foil member for closing the opening; and a bottom opening; providing a closure having an opening defined by an outwardly curled edge, the closure comprising: a generally planar centre panel; and a downwardly extending sidewall depending from a peripheral region of the centre panel and terminating with an inwardly directed curl around the circumference of the sidewall, wherein the inwardly directed curl comprises collapsed portions where the curl has been collapsed and lug portions where the curl has not been collapsed, the closure and the container body having relative dimensions to allow the lug portions to pass over said curled edge during closure and to be retained beneath the curled edge to resist removal of the closure and wherein the closure is dimensioned such that the inner disc region closure is in close proximity to the foil; providing the foil member; affixing the foil member to the inwardly directed bead; attaching the closure to the container body at the top opening such that the lug portions pass over the curled edge and are retained beneath the curled edge; filling the container through the bottom opening; wherein the centre panel of the closure is configured to support the foil member during filling to prevent the foil member from detaching from the inwardly directed bead.
14. 14. A method as claimed in Claim 13, comprising: providing a metal end and seaming the metal end to the bottom opening to close the bottom opening in a substantially airtight manner.