AU2008243146B2 - A resealable closure for a container - Google Patents

Abstract

A resealable closure (10) for an open topped container (12), such as a can made from plastic for containing a liquid such as paint. The container (12) includes an opening defined by a rim (16) and has a radially outward formation (18) adjacent to the rim (16). The closure (10) includes a substantially rigid plastic cover (22) having a peripheral portion (24) for sealingly engaging the rim (16) and a flexible elastomeric ring (28) joined to the plastic cover (22) that defines an outer skirt (34) for the closure (10). The elastomeric ring (28) includes an element (30) for engaging the radially outward formation (18) of the container (12) to retain the peripheral portion (24) of the plastic cover (22) in sealed engagement on the rim (18). The skirt (34) is manually manipulable for removal of the closure (10) from the container (12) when the closure (10) is assembled thereon. (Fig 1) Z+IG 3'f ;- o,

Description

AUSTRALIA Patents Act 1990 ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Invention Title: A RESEALABLE CLOSURE FOR A CONTAINER Applicant: NCI Holdings Pty Ltd The following statement is a full description of this invention, including the best method of performing it known to me: 1 W:\SASKIA\Patents\841 761 cap 7.11 .08.doc 2 A RESEALABLE CLOSURE FOR A CONTAINER This Application claims priority from Australian Provisional Application No. 2007906123 filed on 7 November 2007, the contents of which are to be taken 5 as incorporated herein by this reference. Technical Field The present invention relates to a resealable closure for an open topped container, the resealable closure in combination with the open topped 10 container and methods for forming the resealable closure. The container with which the closure is usable includes an opening defined by a rim and has a radially outward formation adjacent to the rim. The invention will be described herein in relation to a closure for a container such as a can, for example of plastic, for containing a liquid such as paint, however it is to be understood that 15 the closure may be used for other types of containers for containing other types of product. Background It is often desired by consumers that a container of product after first 20 being opened, be re-closable with the container closure or lid. This is particularly so for containers having a capacity such that all of the product in the container is unlikely to be used at one time. For example, paints or other industrial liquids may be sold in cans having a capacity of 10 litres or larger. Thus the can needs to be resealed to preserve the remaining paint or other 25 liquid for use at a later time. It is also desirable for consumer acceptance that the closure be relatively easily removed and reapplied to the container. Use of plastic closures is known, however given the requirement for structural strength of plastic closures (for example for stacking), such closures may require a 30 reasonably large effort and/or the aid of a tool to obtain mechanical advantage to pry them off the container. 9 10957 pro spei 3 Disclosure of the Invention According to the invention there is provided a resealable closure for an open topped container, the container including an opening defined by a rim, the container having a radially outward formation adjacent to the rim, the 5 closure including a plastic cover including a peripheral portion for sealingly engaging the rim and an elastomeric ring that defines an outer skirt for the closure, joined to the plastic cover, the elastomeric ring including an element for engaging the 10 radially outward formation of the container to retain the peripheral portion of the plastic cover in sealed engagement on the rim, wherein the skirt is manually manipulable for removal of the closure from the container when the closure is assembled thereon. The term "ring" is to be understood as encompassing non-circular forms 15 as well as circular. Thus the invention is intended to cover closures for containers of circular, oval, hexagonal, square, rectangular or other shaped cross section. The present invention provides a closure which may be constructed of a substantially rigid plastic cover and a flexible elastomeric ring which are 20 permanently joined together. Thus to a user, the closure is a single item. The elastomeric ring may be joined to the plastic cover by one shot moulding, over moulding or other fusing or welding. Compared to known plastic closures having structural strength, the closure of the present invention is relatively easily removed and reapplied to a 25 container by manual manipulation of the skirt of the elastomeric ring. The closure also has advantages over known plastic closures that are sufficiently soft to allow them to be removable from and resealable onto a container. Unlike soft plastic closures, the closure in accordance with the present invention has structural strength due to the stiff plastic cover of the 30 closure. This improves the top load performance of the container when the closure is assembled thereon. The engagement of the element of the elastomeric ring with the radially outward formation retains the peripheral portion of the plastic cover in sealed engagement on the rim of the container. The engagement is sufficiently strong a810957 po Wi 4 in some embodiments of the invention to satisfy "drop tests" according to industry standard AS.2767. The radially outward formation of the container adjacent to the rim may be a curl, fold, roll, bead or the like. It may be at the rim or on a side wall of the 5 container, spaced downwardly from the rim and it may extend continuously around the container or be interrupted to provide lengths of curl, fold, roll or bead, as the case may be, around the container periphery. Preferably, the radially outward formation has a catch surface which the element of the elastomeric ring may engage. 10 The element of the elastomeric ring may define a shoulder for engaging a catch surface provided by the radially outward formation of the container. The shoulder assists in improving the engagement between the element and the radially outward formation so as to improve the ability of the container to satisfy industry "drop tests". Greater "drop test" performance may be achieved 15 by increasing the diameter of the radially outward formation relative to the container side wall. The shoulder may then be formed having dimensions to allow maximisation of the contact between the shoulder and the catch surface. The skirt may sit outwardly from the container, for example from the container side wall, when the closure is assembled on the container. This 20 provides space for finger access to manipulate the skirt for removal of the closure from the container. The peripheral portion of the plastic cover may include a channel which seats over the container rim. The channel assists in sealingly engaging the rim. 25 In an embodiment, the elastomeric ring and plastic cover are fused together. The elastomeric ring and plastic cover could also be joined by other means, such as by adhesives. The elastomeric ring could be made from natural or synthetic rubber and the plastic cover could be made from polypropylene. Alternatively, the 30 plastic cover could be made from high density polyethylene and the elastomeric ring made from ethylene vinyl acetate. If both the plastic cover and elastomeric ring are made from polypropylene based material the two components may be easily fused 5 together. In addition, components made from polypropylene based materials can be recycled together. The present invention also includes a closure as described above when assembled on a container. It extends to methods for forming a resealable 5 closure as described above, three preferable methods being as follows: moulding the plastic cover and over moulding the elastomeric ring; simultaneously moulding the plastic cover and elastomeric ring; and separately moulding the plastic cover and elastomeric ring and then fusing the two components together. 10 For a better understanding of the invention and to show how it may be carried into effect, embodiments thereof will now be described, by way of non limiting example only, with reference to the accompanying drawings. Brief Description of the Drawings 15 Figure 1 is a side elevational, cross-sectional, partial view of a closure according to an embodiment of the present invention assembled on a container; Figure 2 is a side elevational, cross-sectional, partial view of a closure according to an embodiment of the present invention; 20 Figure 3 is a perspective view of a substantially rigid plastic cover and a flexible elastomeric ring according to an embodiment of the present invention, the substantially rigid plastic cover and a flexible elastomeric ring being shown unjoined; Figure 4 is a side elevational, cross sectional, partial view of a 25 substantially rigid plastic cover and a flexible elastomeric ring according to an embodiment of the present invention, the substantially rigid plastic cover and a flexible elastomeric ring being shown unjoined; Figure 5 is a side elevational, cross-sectional, partial view of a closure according to a second embodiment of the present invention assembled on a 30 container; Figure 6 is a side elevational, cross-sectional, partial view of a closure according to the second embodiment of the present invention; Figure 7 is a perspective view of a substantially rigid plastic cover and a flexible elastomeric ring according to the second embodiment of the present 9 10957 pr sci 6 invention, the substantially rigid plastic cover and a flexible elastomeric ring being shown unjoined; and Figure 8 is a side elevational, cross sectional, partial view of a substantially rigid plastic cover and a flexible elastomeric ring according to the 5 second embodiment of the invention, the substantially rigid plastic cover and a flexible elastomeric ring being shown unjoined. Detailed Description of the Invention Fig. 1 shows a resealable closure 10 assembled on an open topped 10 container 12. Fig. 2 shows the resealable closure 10 separate from container 12. The container 12 is typically a can made of plastic and is for containing a liquid such as paint. The container 12 is cylindrical and has a side wall 14 and an opening defined by a rim 16 with a radially outward formation 18 at the rim 16. The radially outward formation 18 has a catch surface 20. The resealable 15 closure 10 includes a substantially rigid plastic cover 22 having a peripheral portion 24 for sealingly engaging the rim 16, the peripheral portion 24 having a downwardly open channel 26 which seats over the rim 16. The peripheral portion 24 also has chamfer 23 for lidding purposes. The resealable closure 10 includes a flexible elastomeric ring 28 joined to the substantially rigid plastic 20 cover 22. Figs. 1 and 2 show the two components joined by adhesives with a definite join line 29 between flexible elastomeric ring 28 and substantially rigid plastic cover 22. Alternatively, the two components could be fused or welded, in which case there would be a join zone instead of a definite join line 29. 25 The flexible elastomeric ring 28 has an element 30 which is engaged with the radially outward formation 18. In particular, a shoulder 32 of the element 30 is engaged with the catch surface 20. The flexible elastomeric ring 28 also has a skirt 34 extending downwards from the rim 16 and surrounding the container 12. 30 The engagement of the element 30 of the flexible elastomeric ring 28 with the radially outward formation 18 retains the peripheral portion 24 in engagement on the rim 16. In addition, the contacting surfaces of wall 25 of the peripheral portion 24 and the inner surface of side wall 14 may provide a frictional seal, sealing liquid into the container 12. In another embodiment, IIo957 po spi 7 gasket material may be used to provide a seal, for example where the container is made of metal. The resealable closure 10 is easily assembled onto the container 12, by pressing closure 10 onto the rim 16 of the container 10 so that the rim 16 seats 5 within the downwardly open channel 26 of the substantially rigid plastic cover 22. As the closure 10 is pressed onto the rim 16, the flexible elastomeric ring 28 stretches over the radially outward formation 18 and then retracts radially inwardly such that the shoulder 32 of the element 30 engages with the catch surface 20 of the radially outward formation 18. 10 Although the radially outward formation 18 is shown at the rim 16 in Fig. 1, in other embodiments the radially outward formation 18 could be positioned on the side wall 14, adjacent the rim 16. The radially outward formation 18 could be positioned at any location on the side wall 14 provided that the flexible elastomeric ring 28 has a sufficient width such that the element 30 15 engages with the radially outward formation 18. Many cross sectional shapes of the flexible elastomeric ring 28 and the radially outward formation 18 are possible. Also, many shapes of container 12 that allow elastomeric ring 28 to perform its function are possible. Preferably, the cross-sectional shape of the radially outward formation 18 includes an 20 undersurface with which the element 30 of the flexible elastomeric ring 28 is engageable. In Fig. 1, the catch surface 20 provides such an undersurface. The engagement of the shoulder 32 of the element 30 and the catch surface 20 of radially outward formation 18 improves the ability of the container 12 to survive industry "drop tests". 25 An element 30 with a greater width extending downward of rim 16 and/or with a thickness so that the shoulder 32 touches the side wall 14 of the container 12 when the closure 10 is assembled thereon may provide a stronger engagement with the catch surface 20, improving the "drop test" performance of the container 12. Also, increasing the diameter of the radially 30 outward formation 18 relative to the side wall 14 may also improve the ability of the container 12 to satisfy industry "drop tests". The substantially rigid plastic cover 22 also improves the top load performance of the container 12 by providing a stiff or substantially rigid surface which does not easily bend or stretch under load. Loads may be 810957prospi 8 placed on top of the container 12 with the resealable closure 10 assembled thereon, for example multiple filled containers 12 could be stacked on top of each other. The substantially rigid plastic cover 22 is preferably made from polypropylene, but could be made from other rigid plastics, for example, high 5 density polyethylene. The resealable closure 10 can be removed from the container 12 by manual manipulation of the skirt 34 outwardly in the direction of arrow 36 to peel the element 30 of the flexible elastomeric ring 28 away from the radially outward formation 18 and lift the resealable closure 10 from the rim 16. The 10 thumb of an operator may bear on the upper surface of the closure 10 while the operator's fingers lever the skirt 34 outwardly. There is space 38 between the skirt 34 and the side wall 14 to allow finger access to lever the skirt 34 outwardly. The ease with which the closure 10 may be assembled on or removed 15 from the container 12 depends on the elasticity of the flexible elastomeric ring 28. The more elastic the flexible elastomeric ring 28, the easier it is to apply and remove the closure 10. The only requirement is that there be sufficient rigidity for the radially outward formation 18 to retain the substantially rigid plastic cover 22 in position on the rim 16 so as to survive, for example, for this 20 embodiment, industry "drop tests". The flexible elastomeric ring 28 could be made from natural or synthetic rubber or ethylene vinyl acetate and is preferably made from synthetic rubber that is polypropylene based. An advantage of a closure 10 having both the substantially rigid plastic cover 22 and flexible elastomeric ring 28 made from polypropylene based material is 25 ease of fusing together the two components. Another advantage is that closure 10 could be recycled without separating the two components. Figs. 3 and 4 show the substantially rigid plastic cover 22 and flexible elastomeric ring 28 unjoined. The two components could be moulded separately, as shown, and then fused together by applying heat until the 30 components soften and merge and then allowing the components to solidify into one unit. Alternatively, the two components could be formed by one-shot moulding, for example by simultaneously injecting plastic material and elastomeric material into different channels of a mould. In a further alternative, 10957 pr ipeci 9 the closure 10 may be formed by over moulding the flexible elastomeric ring 28 to the substantially rigid plastic cover 22 or vice versa. Figs. 5 to 8 show a second embodiment of the present invention, which provides improved "drop test" performance of the container 12. 5 As shown in Fig. 5, in the second embodiment the radially outward formation 18 of the container 12 has a greater diameter relative to the side wall 14 of the container 12 and therefore has a larger catch surface 20. In addition, the element 30 of flexible elastomeric ring 28 has a larger shoulder 32 that engages with catch surface 20. The larger area of contact between catch 10 surface 20 and shoulder 32 increases the strength of the engagement between the catch surface 20 and shoulder 32. This improves the "drop test" performance of the container 12. Other features of the second embodiment include the angled portion 37 of the radially outward formation 18 and, as seen in Fig. 6, the side surface 35 15 of the element 30. When the closure 10 is assembled on the container 12, the flexible elastomeric ring 28 is compressed by the angled portion 37 and the side surface 35 sits against the side wall 14 of the container 12 adjacent to the radially outward formation 18. These two features improve the engagement between the flexible elastomeric ring 28 and radially outward formation 18 and 20 therefore improve the "drop test" performance of the container 12. In the second embodiment, the substantially rigid plastic cover 22 has upwardly open channel 40, structural supports 42 as seen in Fig. 7, and a downwardly open channel 44 as seen in Fig. 8. These features improve the ease with which automatic lidding machines can assemble the closure 10 onto 25 the container 12. Another feature of the second embodiment is that the flexible elastomeric ring 28 has a thinner skirt 34, which means that the space 38 between the skirt 34 and side wall 14 is increased, allowing better finger access to lever skirt 34 outwardly. The thinner skirt 34 also facilitates stacking 30 of containers 12. The invention described herein is susceptible to variations, modification and/or additions other than those specifically described and it is to be understood that the invention includes all such variations, modification and/or additions which fall within the scope of the following claims. 3 1o%7 , om

Claims (15)

1. A resealable closure for an open topped container, the container including an opening defined by a rim, the container having a radially outward 5 formation adjacent to the rim, the closure including a plastic cover including a peripheral portion for sealingly engaging the rim and an elastomeric ring that defines an outer skirt for the closure, joined to the plastic cover, the elastomeric ring including an element for engaging the 10 radially outward formation of the container to retain the peripheral portion of the plastic cover in sealed engagement on the rim, wherein the skirt is manually manipulable for removal of the closure from the container when the closure is assembled thereon. 15

2. A resealable closure as claimed in claim 1, wherein the element of the elastomeric ring defines a shoulder for engaging a catch surface provided by the radially outward formation of the container.

3. A resealable closure as claimed in claim 1 or 2, wherein the peripheral 20 portion of the plastic cover for sealingly engaging the container rim includes a channel which seats over the container rim.

4. A resealable closure as claimed in claim 1, 2 or 3, wherein the skirt sits outwardly from the container when the closure is assembled thereon. 25

5. A resealable closure as claimed in any one of the preceding claims, wherein the elastomeric ring and plastic cover are fused together.

6. A resealable closure as claimed in any one of the preceding claims, 30 wherein the elastomeric ring is made from natural or synthetic rubber.

7. A resealable closure as claimed in any one of the preceding claims, wherein the plastic cover is made from polypropylene. 31097prso 11

8. A resealable closure as claimed in any one of the preceding claims, wherein the plastic cover and elastomeric ring are both made from polypropylene based material. 5

9. A resealable closure as claimed in any one of claims 1 to 6, wherein the plastic cover is made from high density polyethylene and the elastomeric ring is made from ethylene vinyl acetate.

10. A resealable closure as claimed in any one of the preceding claims in 10 combination with an open topped container, the container including an opening defined by a rim including a radially outward formation, wherein the closure is in sealed engagement with the container.

11. A method for forming a resealable closure for an open topped container, 15 the container including an opening defined by a rim, the container having a radially outward formation adjacent to the rim, the method including the steps of moulding a plastic cover having a peripheral portion for sealingly engaging the rim and 20 over moulding an elastomeric ring that defines an outer skirt for the closure to the plastic cover, the elastomeric ring including an element for engaging the radially outward formation of the container to retain the peripheral portion of the plastic cover in sealed engagement on the rim, wherein the skirt is manually manipulable for removal of the closure from the 25 container when the closure is assembled thereon.

12. A method for forming a resealable closure for an open topped container, the container including an opening defined by a rim, the container having a radially outward formation adjacent to the rim, the method including the step of 30 simultaneously moulding a plastic cover having a peripheral portion for sealingly engaging the rim and an elastomeric ring that defines an outer skirt for the closure, such that the plastic cover and the elastomeric ring fuse together, the elastomeric ring including an element for engaging the radially outward formation of the container to retain the peripheral portion of the plastic S1097 pov speci 12 cover in sealed engagement on the rim, wherein the skirt is manually manipulable for removal of the closure from the container when the closure is assembled thereon. 5

13. A method for forming a resealable closure for an open topped container, the container including an opening defined by a rim, the container having a radially outward formation adjacent to the rim, the method including the steps of moulding a plastic cover having a peripheral portion for sealingly 10 engaging the rim; moulding an elastomeric ring that defines an outer skirt for the closure; and fusing together the elastomeric ring and the plastic cover wherein the elastomeric ring includes an element for engaging the 15 radially outward formation of the container to retain the peripheral portion of the plastic cover in sealed engagement on the rim, wherein the skirt is manually manipulable for removal of the closure from the container when the closure is assembled thereon. 20

14. A resealable closure for an open topped container substantially as hereinbefore described with reference to the accompanying drawings.

15. A method for forming a resealable closure for an open topped container substantially as hereinbefore described with reference to the accompanying 25 drawings. 810957 pr qpc