AU2004293124B2 - A reusable closure with a locking ring for a container - Google Patents

Abstract

A reusable closure (20) for an open topped container (21), the container having a side wall (23) and a top opening defined by a rim (27). The closure (20) has a cover (22) that includes a peripheral channel (25) which engages over the container rim (27). Securing lugs (28) are pivotally attached to an outer wall (26) of the channel (25) by hinges (32) which bias lugs (28) outwardly. A locking ring (36) is slideable downwardly to press the securing lugs (28) inwardly against the container side wall (23) to secure the closure (20) onto the container (21). The securing lugs (28) include beads (40) for engaging a complementary groove (41) in the container side wall. The locking ring (36) is slideable upwardly to release the securing lugs (28), which spring outwardly due to the bias provided by the hinges (32). The closure (20) is readily applicable to a container to re-seal it and is readily removable by a consumer. Due to the biased hinging of the securing lugs (28) the closure can be made from a substantially rigid plastics material thereby avoiding problems due to the flexibility of prior art closures.

Description

WO 2005/051792 PCT/AU2004/001646 A reusable closure with a locking ring for a container Technical Field The present invention relates to a reusable closure for an open topped 5 container. The container with which the closure is usable comprises a side wall that extends to a rim that defines a top opening of the container. The invention will be described herein in relation to a closure for a container such as a can for containing a liquid such as paint, however it is to be understood the closure may be used'for other types of containers for containing other types of products, 10 usually liquids. Background It is often desired by consumers that a container of product, for example a can of paint, after first being opened, be re-closable with the container closure 15 or lid. This is particularly so for cans having a capacity such that all of the paint in the can is not used at the one time. Thus the can needs to be resealed to preserve the remaining paint for use at a later time. It is also desirable for consumer acceptance that the closure be relatively 20 easily removed from and re-applied to the container. Use of plastic lids is known, however such lids need to have some flexibility to allow for them to be manipulated, for example stretched, for removal from and re-application to the container. Nevertheless, given the requirement for structural strength of plastic closures (for example for stacking), such closures tend still to require a 25 reasonably large effort and/or the aid of a tool to obtain mechanical advantage to pry them off the container. Another problem due to the flexibility of such plastic closures is that dry material on the inside surface of the closure tends to come off and fall back into the container body. This is a particular problem for cans of paint in that dried flakes of paint can fall into the paint in the container 30 and cause blockages in paint spray guns. This problem may occur during transport of a container as well as during application or removal of its closure.

2 Disclosure of The Invention According to a first aspect of the invention there is provided a re-usable closure for an open topped container wherein the container has a side wall that extends to a rim that defines a top opening of the container, the closure including a cover having a 5 peripheral structure for engaging the container rim, the peripheral structure including an outer wall for surrounding the side wall of a container, the cover further including at least two spaced securing lugs that are each joined the outer wall by a hinge so as to depend from the outer wall whereby they are pivotally movable away from the container side wall, wherein each hinge is such that it biases its securing lug to a 10 normal position whereat it is angled outwardly away from the side wall of a container, the closure also including a locking element surrounding the outer wall of the cover and slideably moveable thereover the depending securing lugs to press the securing lugs inwardly against the container side wall thereby securing the closure on the container, wherein the locking element is slideably moveable upwards to release the 15 securing lugs for them to pivot to their normal position. A closure according to the first aspect of the invention provides an arrangement for readily releasing the securement of the closure on a container, thereby allowing easy removal of the closure, and for readily re-securing the closure onto the container, for example to re-seal the closure thereon. This arrangement 20 involves a consumer merely moving the locking element upward and downward. Also the closure is readily applied in the first instance by a packager. The locking element is preferably a ring which is slideable upwardly and downwardly (relative to the normal upright orientation of an open-topped container) over the outer wall and depending securing lugs of the closure. 25 A closure according to the invention most commercially is circular in accordance with a circular cross-section container. However, it is within the scope of the invention that the closure may be other than circular to suit differently shaped containers, for example oval, square or rectangular. A closure according to the invention may be manufactured from a harder, more 30 rigid plastics material than prior plastic closures in that the need for the closure to flex C:pofwrvd\SPEC-773319.doc 3 or stretch is substantially eliminated. This reduces the likelihood of dry material, for example paint flakes, detaching from the closure and falling back into the container. Preferably the closure as a whole is formed from a suitable plastics material, for example polypropylene, to provide the hardness and rigidity needed to avoid or at 5 least substantially lessen the possibility of dry material detaching from the inside of the closure and falling into the container contents, which is a particular problem with containers of paint. The cover part of the closure may have a structural design, for example a grid pattern, that adds further rigidity. According to a second aspect of the invention, for a closure that is wholly 10 formed of a plastic material, the closure, which in general comprises two parts, namely the cover with its depending securing lugs as a first part and the locking element as a second part, is formed as a one-piece moulding. Thus the cover with its depending securing lugs (constituting a first part of the closure) and the locking element (constituting a second part of the closure) are formed together such that they 15 are joined as a one-piece moulding. The join is such that the C:\pofvrdSPEC-773319 doc WO 2005/051792 PCT/AU2004/001646 4 locking element (second part) is separable from the cover (first part) during the initial assembly process of applying the closure to the container. . Alternatively the closure may be a composite structure comprising a 5 metal lid having a plastic ring effectively permanently secured thereto, whereby the plastic ring and the metal lid constitute the cover portion of the closure, that is, the portion having the outer wall from which the at least two securing lugs depend. An example of such a composite structure is disclosed in the applicant's International Patent Application No. WO 01/44069 Al 10 (PCT/AUOO/01541). With such a composite structure, manufacture of the closure may also be completed in a single moulding operation, that is, the metal lid part may be provided and the remaining plastic parts of the closure moulded onto it. 15 Although a cover according to the invention will typically be wholly formed of a plastic material, or be a composite plastic/metal structure as in International Patent Application No. WO 01/44069 Al, it is considered that a wholly metal structure is possible as is a composite structure having a plastic cover portion and a metal surround that provides at least the outer wall of the 20 peripheral structure, the depending securing lugs and the locking element. The closure may be moulded from a plastic material with the securing lugs in their "normal" position, that is, where they are angled outwardly to a position whereat in use of the closure, the securing lugs are angled away from 25 the container side wall. This creates a memory in the material of the hinges whereby each hinge biases its securing lug outwardly to its normal position such that each securing lug will return to this position whenever the locking element is in its upper position whereat the securing lugs are released. This contributes to the ease of use of the closure. Thus removal of the closure is 30 achieved by lifting the locking element which allows the securing lugs to spring outwardly and for the continual lifting of the locking element to remove the whole closure in one basic motion. To assist in removing the closure from a container, at least one of the securing lugs may include a depending tag which WO 2005/051792 PCT/AU2004/001646 5 a user may grip and use to lever the securing lug outwardly for it to bear against and thus cam the locking element upwardly. Preferably the securing lugs include a formation on their inner surfaces 5 for engaging a formation on the side wall of the container. For example, such a formation may be a bead which engages in a groove formed in the container side wall. Alternatively the formation could be an external curl or the like at the rim of the container. Such formations preferably are shaped to provide a camming action to "pull down" the closure onto the container rim. This provides 10 an increased closing force and where the closure is such that it sealingly engages the container rim, ensures that an effective seal is established. Preferably there are several securing lugs arranged to extend all the way around the closure. 15 For a locking element that is a ring which is slideable upwardly and downwardly, the outer wall of the closure may include grooves in the direction of movement of the locking ring and the locking ring may include complementary ribs which ride within the grooves to guide the downwards and upwards 20 movement of the locking ring for pressing and releasing the securing lugs. Preferably the locking ring includes axial ribs whereas the outer wall of the cover is not grooved such that only the surfaces of the ribs slide over the outer wall. With this structure, the ribs impart strength to the locking ring whilst friction is reduced between the ring and the outer wall thereby easing the 25 slideability of the ring. Preferably the locking element and the securing lugs of the closure include complementary interengagable elements for releasably holding the locking element in its locking position whereat it presses the securing lugs 30 against the container side wall. Such elements may be dimples on the locking element inside surface which snap into complementary depressions formed in the outer surfaces of the securing lugs and which are relatively readily releasable by applying an increased moving force to the locking element. Alternatively such releasable holding elements may include interengaging parts 6 requiring a positive action for release prior to or as part of moving the locking element, for example a press button arrangement. Persons skilled in the art will appreciate that many suitable releasable holding arrangements are possible. The cover and the outer wall define a peripheral structure for engaging the 5 container rim and this may comprise a channel which seats over the container rim, wherein the outer wall is a wall of the channel. Normally there will be sealing engagement between the closure and the container rim in which case the peripheral structure may include a gasket compound which is compressed onto the rim when the closure is secured to the container thereby ensuring the closure is sealingly retained 10 on the container. Alternatively the closure may include a spigot for frictionally engaging the inside surface of the side wall of the container adjacent the rim for providing a seal between the closure and the container. It is to be understood that the invention whilst encompassing resealable closures, is intended to encompass reusable closures that do not establish a hermetic seal between the closure and the 15 container. For a better understanding of the invention and to show how the same may be performed, an embodiment thereof will now be described, by way of non-limiting example only, with reference to the accompanying drawings. 20 Brief Description of the Drawings Fig. 1 shows a closure according to an embodiment of the invention with its locking element in its locked position. Fig. 2 shows the closure of Fig. 1 with its locking element in an unlocked position and illustrative of the closure formed as a one-piece moulding. 25 Fig. 3 shows the closure of Fig. 1 and movement of the locking element for securing the closure onto a container. Fig. 4 is a schematic cross-sectional view of the closure as in Fig. 2 on a container, with only a portion of the closure and the container shown. Fig. 5 is a schematic cross-sectional view of the closure as in Fig. 3 on a 30 container, with only a portion of the closure and the container shown. Fig. 6 is a schematic cross-sectional view of the closure as in Fig. 1 on a container, with only a portion of the closure and the container shown. C:pof\word\SPEC-773319.doc WO 2005/051792 PCT/AU2004/001646 7 Fig. 6 is a schematic cross-sectional view of the closure as in Fig. I on a container, with only a portion of the closure and the container shown. Detailed Description of Preferred Embodiment 5 The closure 20 shown in the figures is wholly formed of plastic and may also be made as a one piece moulding (as will be described in more detail below). The closure 20 is for a circular cross section container (not illustrated) and thus is itself circular. The closure 20 is for closing the top opening of a container 21 (see Figs. 4-6), the container having a side wall 23 and the top 10 opening being defined by a rim 27. The closure 20 includes a central cover 22 that has a peripheral structure 24 that forms a channel 25. The peripheral channel 25 includes an outer wall 26 that surrounds the upper end of the side wall 23 of a container 21 when the rim 27 of the container opening is received within the peripheral channel 25. A plurality of securing lugs 28 depend from a 15 bottom edge 30 of the outer wall 26 and are affixed thereto by hinges 32 for the securing lugs 28 to be pivotally moveable towards and away from the container side wall 23. The securing lugs 28 extend around the closure 20 with small gaps 34 therebetween and the moulding is such that each hinge 32 normally holds its securing lug 28 in an outwardly angled position, that is, each hinge 32 20 biases its securing lug 28 outwardly for the securing lug 28 to have a normal position whereat it is angled outwardly away from the side wall 23 of the container 21 (see Figs. 2 and 4). The closure 20 also includes a locking element 36 in the form of a ring 25 which surrounds the outer wall 26 of the peripheral channel 25 of the cover 22 and is moveable over the outer wall 26 and over the depending securing lugs 28 to cause the securing lugs 28 to pivot inwardly towards the container side wall 23. The locking ring 36 is a sliding fit around the outer wall 26 and when manually pressed, it slides downwardly over that wall 26 until its lower edge 38 30 contacts the outwardly angled upper surfaces of the securing lugs 28 whereupon further downward movement of the locking ring 36 cams the securing lugs, 28 inwardly for them to pivot about hinges 32 (and against the bias of the hinges 32) until they press against the container side wall. Figs. 3 WO 2005/051792 PCT/AU2004/001646 8 and 5 illustrate the downward movement of locking ring 36 (see arrow A) to pivot the securing lugs 28 inwardly (see arrow B on Fig. 5). The securing lugs 28 each include a formation, namely a transverse 5 bead 40 on their inner surfaces for engaging a complementary formation, namely a circumferential groove 41 in the container side wall 23. Such a groove 41 may be shaped relative to the shape of the beads 40 that as the securing lugs 28 and thus the beads 40 are pressed inwardly by the locking ring 36 the interengagement of the beads 40 and container groove 41 provides a 10 camming action to more tightly "pull" the closure 20 down onto the container rim 27. The locking ring 36 is pushed downwardly until the beaded securing lugs 28 are tightly pressed against the container side wall 23 (in groove 41) thereby securing the closure 20 on the container 21. 15 When it is desired to remove the closure 20 from a container, all that is required is for an operator to manually slide the locking ring 36 upwardly for it to release the securing lugs 28 allowing them to spring outwardly to their normal position under the bias provided by the hinges 32, which bias is due to the "memory" of the plastic material of the hinges 32 to return to their as moulded 20 normal position. Several of the securing lugs 28 may include a depending tag 54. These tags 54 may be used to facilitate removing the closure 20 from a container. Thus instead of an operator seeking to manually slide the locking ring 36 25 upwardly, the operator may grip two generally oppositely located tags 54 (one in each hand) and use them to lever their associated securing lugs 28 outwardly for the outer surfaces of those securing lugs 28 to apply a camming action to the adjacent lower regions of the locking ring 36 to thus cause the locking ring 36 to slide upwardly for it to release all of the securing lugs 28. Clearly, the tags 30 54 may be used to start the release action and then the locking ring 36 itself gripped and lifted to complete the removal action. Also, clearly, one tag 54 may be used in conjunction with an operator simultaneously applying a lifting force directly to the locking ring 36.

WO 2005/051792 PCT/AU2004/001646 9 As best seen in Fig. 2, the locking ring 36 includes a circumferential flange 42 on its inside surface adjacent its lower edge 38 and axial ribs 44 extending from the flange 42 and spaced around the inner surface of the locking ring 36. The flange 42 and ribs 44 impart a degree of rigidity to the locking ring 5 36 for it to function as required. Also, as it is the inner facing surfaces of the ribs 44 which slide over the relatively smooth surface of outer wall 26 the frictional engagement between these surfaces is less than would be the case if the locking ring 36 was not ribbed or if the ribs meshed with complementary shaped grooves in the outer wall 26 (because the area of contact is less). This 10 reduces the manual force that needs to be applied to the locking ring 36 to slide it down over the securing lugs 28 or to pull it up (possibly via or with the assistance of the tags 54) to release the securing lugs 28. As best illustrated in Fig. 2, the closure 20 is preferably formed as a one 15 piece moulding wherein the locking ring 36 at its lower edge 38 is joined to the upper radially outermost edge of the peripheral structure 24 of the cover 22 (that is, at the edge where outer wall 26 depends from cover 22) by a frangible join 48. The frangible join 48 is a discontinuous thin section that is readily breakable during the initial assembly process of applying the closure 20 to a 20 container in an automated packaging line. The join 48 is discontinuous because the lower edge 38 of the locking ring 36 is formed to have recesses 56 around it, with each recess 56 corresponding to a securing lug 28 that includes a tag 54. Thus when a securing lug 28 is levered outwardly via a tag 54, that securing lug 28 is accommodated in a recess 56 which facilitates the use of the 25 securing lugs 28 via the tags 54 to raise the locking ring 36. Thus the recesses 56 assist the levering action of the securing lugs 28 on the locking ring 36. They also prevent turning or twisting of the locking ring. The securing lugs 28 also include a circumferential bead 50 on their 30 outer surfaces near their lower ends which provides a shoulder over which a complementary bead 52 on the inner surface of flange 42 of locking ring 36 rides. The beads 52 seat over the shoulders of beads 50 when the locking ring 36 is in its lowermost position to "lock" it into place. This locking action is released when it is desired to remove the closure 20 from a container 21 by WO 2005/051792 PCT/AU2004/001646 10 applying a slightly increased lifting force to the locking ring 36, which may be via use of the tags 54. The beads 52 and 50 are interengagable complementary elements for releasably holding the locking ring 36 in its position over the securing lugs 28. 5 The provision of the definitive hinges 32 as such which bias the securing lugs 28 to an outwardly angled normal position means that the closure 20 can be manufactured from a substantially hard and rigid plastics material because both the removal of the closure 20 from and its re-application onto a container 10 are not dependent upon the closure 20 necessarily having to be resilient for it to flex or stretch. Thus it is possible to use a more rigid plastics material for the closure 20 compared to prior art closures and this in turn gives advantages such as increased stacking strength and, for paint packaging applications, less likelihood of dry material falling off the inside surface of the closure into the 15 contents of the container. Fig. 2 illustrates that the hinges 32 for the securing lugs 28 that have tags 54 are single hinges, each having a substantial width relative to the width of its securing lug 28, whereas the hinges 32 for the securing lugs 28 that do not have tags 54 comprise a pair of hinges for each securing lug, with each hinge of a pair located at an edge of a securing lug 28 20 and much shorter in length than the single hinges for the securing lugs 28 that include tags 54. The single hinges 32 for the securing lugs 28 with tags 54 are stronger than the double hinges for the other securing lugs to cater for the increased forces thereon when the tags 54 are used to lever the locking ring 36 upwardly. The securing lugs 28 are also formed to have outward ledges 58 at 25 their lower edges. These provide a stop to prevent the locking ring 36 from being pushed too far over the securing lugs 28. The invention disclosed herein is susceptible to variations, modifications and/or additions other than those specifically described or illustrated and it is to 30 be understood that the invention includes all such variations, modifications and/or additions which fall within the scope of the following claims.

Claims (10)

1. A re-usable closure for an open topped container wherein the container has a side wall that extends to a rim that defines a top opening of the container, the closure including a cover having a peripheral structure for engaging the 5 container rim, the peripheral structure including an outer wall for surrounding the side wall of a container, the cover further including at least two spaced securing lugs that are each joined the outer wall by a hinge so as to depend from the outer wall whereby they are pivotally movable away from the container side wall, wherein each hinge is such that 10 it biases its securing lug to a normal position whereat it is angled outwardly away from the side wall of a container, the closure also including a locking element surrounding the outer wall of the cover and slideably moveable thereover the depending securing lugs to press the securing lugs inwardly against the container side wall thereby securing the closure on 15 the container, wherein the locking element is slideably moveable upwards to release the securing lugs for them to pivot to their normal position.

2. A re-usable closure as claimed in claim 1 wherein each securing lug includes a formation on its inner surface for engaging a complementary formation in the side wall 20 of a container.

3. A re-usable closure as claimed in claim 2 wherein the formation is a bead for engaging in a groove in the side wall of a container.

4. A re-usable closure as claimed in claim 1 wherein at least one of the securing lugs includes a depending tab for an operator to grip to lever the securing lug 25 outwardly to assist in moving the locking element from a position over the depending securing lugs towards a position away from the depending securing lugs.

5. A re-usable closure as claimed any one of claims 1 to 4 or claim 5 wherein the locking element includes axial ribs spaced around its inner surface for sliding over the CWApf-ord\SPEC-773319 doc 12 outer wall whereby areal contact between the locking element and outer wall is reduced for reducing frictional forces between them as the locking element is moved.

6. A re-usable closure as claimed in any one of claims 1 to 5 wherein the locking element and the securing lugs include complementary elements which are 5 interengagable to releasably hold the locking element in its position over the securing lugs.

7. A re-usable closure as claimed in any one of claims 1 to 6 wherein the peripheral structure is a channel which seats over the container rim.

8. A re-usable closure as claimed in any one of claims 1 to 7 formed as a one 10 piece moulding wherein a l6wer edge of the locking element is attached to an upper outer edge of the peripheral structure by a frangible join for the locking element to be separable from the cover during initial packaging assembly of the closure onto a container.

9. A package including a re-usable closure as claimed in any one of claims 1 to 8 15 and a container, the container having a side wall that extends to a rim that defines a top opening of the container, the closure closing the top opening of the container.

10. A re-usable closure substantially as hereinbefore described with reference to any one of the embodiments shown in the drawings. 20 C:\poford\SPEC-773319 doc