KEANE, Brendan (CROWN Packaging Technology, Inc.11535 South Central Avenu, Alsip Illinois, 60803-3418, US)
WILLIAMS, Andrew (CROWN Packaging Technology Ltd, Downsview RoadWantage, Oxfordshire OX12 9BP, GB)
FIELDS, Brian (CROWN Packaging Technology, Inc.11535 South Central Avenu, Alsip Illinois, 60803-3418, US)
KEANE, Brendan (CROWN Packaging Technology, Inc.11535 South Central Avenu, Alsip Illinois, 60803-3418, US)
WILLIAMS, Andrew (CROWN Packaging Technology Ltd, Downsview RoadWantage, Oxfordshire OX12 9BP, GB)
| Claims 1 . A tab for severing the score line of an easy open can end, the tab having a nose and a handle, the tab adapted to be secured to an end panel of such a can end, the tab comprising a bistable portion which, in use and before rupture of the score line, is deformable from a predetermined first state to a predetermined second state, the bistable portion being adapted such that deformation of the bistable portion from first to second states tilts all or part of the handle of the tab upwardly relative to the end panel to define a gap between the handle of the tab and the underlying surface of the can end suitable for finger access; characterised in that the tab further comprises the features of either of the following two options: Option 1 : the tab comprises two elongate bistable arms extending for a distance between the nose and the handle of the tab and disposed on either side of the tab's longitudinal axis, the tab adapted such that, in use, in the first state the elongate bistable arms are flexed to bias the handle of the tab against the underlying surface of the end panel, the tab further comprising a downwardly depressable portion co-operable with the elongate bistable arms such that activation of the downwardly depressable portion laterally twists the bistable arms, the twisting motion transforming the arms into the second state in which they bias the handle of the tab away from the underlying surface of the end panel; Option 2: the handle of the tab comprises a cut-out section to define a ring- shaped handle, the ring-shaped handle comprising the bistable portion, the bistable portion comprising a hinge point and two adjoining portions each extending outwardly from the hinge point, the hinge point being upwardly moveable to flip: from the first state in which the hinge point is downwardly disposed relative to the adjoining parts of the bistable portion of the ring-shaped handle, to the second state in which the hinge point is upwardly disposed relative to the adjoining parts of the bistable portion of the ring-shaped handle, to thereby define a gap between the handle of the tab and the underlying surface of the can end. 2. A tab as claimed in option 1 of claim 1 , wherein the elongate bistable arms extend between i) a location just behind the point at which the tab is secured to the end panel and ii) the handle of the tab. 3. A tab as claimed in option 1 of claim 1 or claim 2, wherein the elongate arms are spaced apart and profiled to define a ring section in the handle of the tab suitable for a user to engage their finger. 4. A tab as claimed in option 2 of claim 1 , wherein the hinge point is centrally located at the rear end of the ring-shaped handle on the tab's longitudinal axis. 5. A tab as claimed in claim 4, wherein the bistable portion is symmetrically disposed about the tab's longitudinal axis. 6. A can end incorporating the tab of any one of claims 1 to 5. 7. A can end as claimed in claim 6, wherein in the first state no part of the tab extends above the uppermost plane defined by the can end. 8. A container to which is fastened the can end of either of claims 6 or 7. 9. A tab, can end or container substantially as described herein, with reference to the accompanying drawings. |
TAB
Technical Field
[0001] The invention relates to a tab which is suitable for use with conventional easy open metal can ends that have a score line defining a wholly or partly removable panel portion. Part of the tab is adapted to be deformable, prior to rupture of the score line, to provide enhanced finger access under the tab.
Background Art
[0002] Easy-open can ends are well known in the field of can manufacture - for example, that described and shown in figures 4 & 5 of US 5413241 (YEH HSI-SHOU) 09/05/1995 . The can end is provided with an end panel provided with a score line defining a prearranged opening area. A tab is secured to the end panel, with the nose of the tab located adjacent the score line. To avoid interference between adjacent can ends during transportation of the can ends themselves, the handle of the tab is located against the outer surface of the end panel. It would remain in this position after attachment of the can end to a can body - as is normal practice for virtually all current easy-open can ends. However, this presents a problem for a consumer wishing to open the can because the consumer must first prise the handle of the tab away from the surface of the end panel in order to lift the tab to rupture the score line. The lack of clearance between the tab handle and the end panel makes this an arduous task, especially for those with weak hands such as those with arthritis or disabled persons.
[0003] WO 03/104092 A (MAEIL DAIRY INDUSTRY CO LTD) 18/12/2003
provides one solution to the above problem of tab access.
WO 03/104092A discloses a can end having a collapsible protrusion under the handle of the tab. The collapsible protrusion initially protrudes upward from the can end to define a minimal (or zero) gap between the tab and the protrusion {providing efficient stackabifity of one can end upon another for storage/transportation purposes), but is deformable downwards from the tab to define a concave finger well under the handle of the tab sufficient for a user to insert their finger {providing finger access under the tab and ease of opening by a consumer).
[0004] However, there are several problems with the protrusion shown and
described in WO 03/104092A:
Firstly, the collapsible protrusion of WO 03/104092A has to occupy a substantial area of the can end in order to define a finger well of sufficient depth to permit a consumer to insert their finger under the handle of the tab.
Secondly, when containers incorporating the can end of
WO 03/104092A are exposed to positive pressure (i.e. where the pressure within the container is greater than that outside), the protrusion can easily revert into its upward state, thereby removing any clearance under the tab and hindering tab access. Positive pressure may arise due to the environment in which containers incorporating the can end are stored, or due to the nature of the product stored within the container. For example, carbonated beverage products provide continual positive pressure. Alternatively, certain food products may expel gases during their storage. Additionally, in the case of containers for housing food products requiring sterilisation, the heat generated from retort processing can result in a build-up of positive pressure within the container.
Thirdly, the protrusion of WO 03/104092A is a non-planar surface, which can present a difficult surface on which to print logos, images or instructions.
[0005] JP 2001341740 A (WATANABE KAZUYOSHI ET AL) 1 1/12/2001
discloses a can end having a tab secured to an end panel, the tab having a nose and a handle disposed on either side of the attachment location of the tab to the end panel. In a first state, the handle of the tab defines a convex profiled button and biases the far end of the handle of the tab against the surface of the end panel. The convex profiled button is deformable downwards to transform into a second state in which the button is concavely profiled and inclines the far end of the handle of the tab away from the surface of the end panel to define a gap under the tab handle.
[0006] An alternative and improved means of providing finger access under the tab of an easy open can end is provided.
Disclosure of Invention
[0007] Accordingly, there is provided a tab for severing the score line of an easy open can end, the tab having a nose and a handle, the tab adapted to be secured to an end panel of such a can end, the tab comprising a bistable portion which, in use and before rupture of the score line, is deformable from a predetermined first state to a predetermined second state, the bistable portion being adapted such that deformation of the bistable portion from first to second states tilts all or part of the handle of the tab upwardly relative to the end panel to define a gap between the handle of the tab and the underlying surface of the can end suitable for finger access; characterised in that the tab further comprises the features of either of the following two options:
Option 1 : the tab comprises two elongate bistable arms extending for a distance between the nose and the handle of the tab and disposed on either side of the tab's longitudinal axis, the tab adapted such that, in use, in the first state the elongate bistable arms are flexed to bias the handle of the tab against the underlying surface of the end panel, the tab further comprising a downwardly depressable portion co-operable with the elongate bistable arms such that activation of the downwardly depressable portion laterally twists the bistable arms, the twisting motion transforming the arms into the second state in which they bias the handle of the tab away from the underlying surface of the end panel;
Option 2: the handle of the tab comprises a cut-out section to define a ring-shaped handle, the ring-shaped handle comprising the bistable portion, the bistable portion comprising a hinge point and two adjoining portions each extending outwardly from the hinge point, the hinge point being upwardly moveable to flip:
from the first state in which the hinge point is downwardly disposed relative to the adjoining parts of the bistable portion of the ring-shaped handle, to the second state in which the hinge point is upwardly disposed relative to the adjoining parts of the bistable portion of the ring-shaped handle, to thereby define a gap between the handle of the tab and the underlying surface of the can end.
[0008] By "bistable portion" is meant a portion of the tab having two defined
stable geometric states. Options 1 and 2 define two forms that the bistable portion of the invention may take.
[0009] Preferably, the elongate bistable arms extend between i) a location just behind the point at which the tab is secured to the end panel and ii) the handle of the tab. For the purposes of the invention, the nose is regarded as being at the front end of the tab and the handle is regarded as being at the rear end of the tab.
[0010] The invention relies upon deformation of part of the tab itself to provide finger access under the handle of the tab prior to rupture of the score line. This is a completely different mechanism to that disclosed in
WO 03/104092A which relies on the can end itself having a deformable finger well (the "collapsible protrusion"). The invention can therefore provide finger access when used on easy open can ends, without the need for a dedicated finger well on the can end itself. However, the tab of the invention can equally be applied to can ends that do have a finger well, whether fixed or moveable (as disclosed in WO 03/104092A).
[001 1] Having, in the first state, the handle of the tab biased against the
underlying surface of the end panel provides the advantage of maximising the stackability of can ends which incorporate the tab of the invention, by minimising the likelihood of interference between the handle of the tab secured to one can end and the end panel of an adjacent can end placed above. This maximises the packing density of a stack of can ends incorporating the tab of the invention during storage and transportation.
[0012] In the case of option 1 , conveniently the elongate arms may be spaced apart and profiled to define a ring section in the handle of the tab suitable for a user to engage their finger.
[0013] In the case of option 2 of the invention, the ring-shaped handle itself
provides bistability, with a user only having to apply minimal upwards force to the far end of the tab handle to cause it to flip into its second state to provide enhanced finger access under the handle. By "minimal upwards force" is meant a force lower than that necessary to cause the nose of the tab to rupture the score line. Conveniently, the hinge point is centrally located at the rear end of the ring-shaped handle on the tab's longitudinal axis. Advantageously, the hinge point is centrally located at the rear end of the ring-shaped handle on the tab's longitudinal axis.
[0014] The tab is generally envisaged to be made of any conventional metal used in the manufacture of tabs for packaging. However, the bistability concept is not material specific and therefore the invention is not limited to specific categories or grades of materials.
[0015] The tab is adapted to be incorporated onto a can end. It is most preferred that when incorporated onto a can end, in the first state no part of the tab extends above the uppermost plane defined by the can end. This latter feature of the invention helps to reduce the risk of damage to the tab during transportation of i) can ends of the invention or ii) containers which incorporate the can ends of the invention, because the tab, in effect, remains recessed below the uppermost plane of the can end. Where the can end is adapted to be fastened onto a can body by seaming, the uppermost plane of the can end is conveniently defined by a seaming panel of the can end.
Brief Description of Figures in the Drawings
[0016] Two embodiments of the present invention are described below, with
reference to the following drawings:
[0017] FIGURE 1 is a perspective view of a can end incorporating a tab according to a first embodiment of the invention and showing the tab in a first predetermined state.
[0018] FIGURE 2 corresponds to figure 1 , but showing the tab in its second
predetermined state.
[0019] FIGURE 3 is a perspective view of a can end incorporating a tab according to a second embodiment of the invention and showing the tab in a first predetermined state. [0020] FIGURE 4 corresponds to figure 3, but showing the tab in its second predetermined state.
[0021] FIGURE 5 shows a can end according to the invention located relative to a container body.
Mode(s) for Carrying Out the Invention
First Embodiment
[0022] Can end 1 includes an end panel 2 provided with a score line 3. The
score line 3 defines a prearranged opening area (an aperture), whereby (in the embodiment illustrated) the whole of the end panel 2 inwards of the score line would be removable from the can end 1. A countersink 4 is located radially outward of the score line 3 (see figure 1 ). A chuck wall 5 extends first upwardly from the bottom of the countersink 4, and then outwardly to define seaming panel 6 (see figure 1 ). The end panel 2 includes strengthening beads 7 to improve the rigidity of the end panel. Tab 10 is secured to the end panel 2 by means of a rivet 50. One end of the tab 10 is provided with a nose 1 1 located adjacent the score line 3. The opposite or rear end of the tab 10 has a handle 12.
[0023] In this first embodiment of the invention (shown in figures 1 & 2), two
elongate arms 13 extend between the rivet 50 and the rear end of the handle 12 of the tab. The arms 13 are symmetrically disposed on either side of the tab's longitudinal axis 14. Figure 1 shows the tab 10 in a first state, in which the elongate arms 13 are flexed to bias the handle 12 of the tab against the portion of the end panel 2 underlying the handle.
[0024] The tab 10 also includes a tongue section 15. As can be seen from
figure 1 , the tongue section 15 extends behind the rivet 50 upwardly and in the general direction of the tab's longitudinal axis 14 towards the handle 12 of the tab 10. The tongue section 15 defines a downwardly depressable button. The tongue section 15 is an integral part of the tab 10 and blends in with the elongate arms 13 via a platform 16. In the first state, this platform 16 is raised slightly above the adjacent region of the tab 10 (see figure 1).
[0025] In the first state, the tab 10 is adapted for optimum stackability of one can end upon another, with the handle 12 of the tab pressing against the underlying surface of the end panel 2. No part of the tab 10 extends above the level of the seaming panel 6 in this first state. Also, in this first state the risk of foreign objects being caught between the tab handle 12 and the end panel 2 is minimised. It is envisaged that the can end 1 would remain in this state all the way through from manufacture to fastening to a container body, to placement of the container on a supermarket shelf.
[0026] However, as will be understood from figure 1 , when the tab 10 is in its first state, it is very hard for a user to engage their finger with the underside of the tab handle 12 to apply the necessary upwards force to cause the tab nose 1 1 to rupture the score line 3. To overcome this problem, a user merely has to apply a downwards force F to the tongue section 15 (as indicated in both figures 1 & 2). The downwards motion of the tongue section 15 deforms the platform 16 downwardly and thereby laterally twists (indicated by arrows T on figure 2) the elongate arms 13 and thereby causes the arms to flip into a second state in which the arms then bias the handle 12 of the tab away from the underlying surface of the end panel 2 (see figure 2). In this second state, a gap 'hi' is defined between the handle 12 and the underlying surface of the end panel 2 (see figure 2). As can be understood from figures 1 & 2, deformation of the elongate arms 13 from first to second states causes the tab handle 12 to tilt or pivot upwardly relative to the tab nose 1 1 and end panel 2 to thereby provide finger access under the handle (indicated by 'hi' on figure 2).
[0027] A user is then able to engage their finger fully with the tab handle 12 to lift and pivot the handle about the rivet 50, and thereby cause the tab nose 1 1 to rupture the score line 3.
Second Embodiment
[0028] Figures 3 & 4 show a second embodiment of the invention, with like
features retaining the numbering of the first embodiment. The can end 1 is identical to those in figures 1 & 2, but having a different tab. The tab 10 incorporates a nose 1 1 and a handle 12. The handle 12 is ring-shaped - similar to the embodiment of figures 1 & 2. However, the ring-shaped handle 12 of this second embodiment includes a bistable portion 18 located approximately between points 'a' and 'b' on figures 3 & 4. The bistable portion 18 is symmetrically disposed about the tab's longitudinal axis 14, having a hinge point 'c' located at the rear end of the tab handle 12.
[0029] Figure 3 shows the tab 10 in its first state, in which the hinge point 'c' is downwardly disposed relative to the adjoining parts ('c-a' and 'c-b') of the bistable portion 18, these adjoining parts extending outward from the hinge point 'c' to points 'a' and 'b' respectively. As for the first embodiment, no part of the tab 10 extends above the level of the seaming panel 6. In this state, a minimal or zero gap is provided between the tab handle 12 and the underlying surface of the end panel 2. As for the first embodiment of the invention, this first state minimises the risks of foreign objects becoming caught between the tab handle 12 and the end panel 2. Again, it is envisaged that the can end 1 would remain in this state all the way through from manufacture to fastening to a container body, to placement of the container on a supermarket shelf.
[0030] However, as for the first embodiment, in this first state it can be difficult for a user to engage their finger with the underside of the tab handle 12 to apply the necessary force to rupture the score line 3. This problem is overcome in this second embodiment by a user applying a minimal upwards force F to the bistable portion 18 in the general vicinity of the hinge point 'c'. This minimal force is sufficient to cause the hinge point 'c' to flip from its downwardly disposed state to a second state in which it is upwardly disposed relative to the adjoining parts ('c-a' and 'c-b') of the bistable portion 18. The transition or flipping between first and second states causes the adjoining parts 'c'-'a' and 'c'-'b' to tilt about points 'a' and 'b'. In this second state, a gap ' i2' is defined between the tab handle 12 and the underlying surface of the end panel 2 (see figure 4). As can be understood from figures 3 & 4, deformation of the hinge point 'c' of the bistable portion 18 from first to second states causes the tab handle 12 to tilt or pivot relative to the end panel 2 to thereby provide finger access under the handle (indicated by ' i2' on figure 4). [0031] Again, a user is then able to engage their finger fully with the tab handle
12 to lift and pivot the handle about the rivet 50, and thereby cause the tab nose 1 1 to rupture the score line 3.
[0032] Figure 5 shows the can end 1 of the second embodiment located relative to a container body 20. The container body 20 is flared 21 at one end. In the example shown in figure 5, the can end 1 would be seamed to the container body by engagement of the flared portion 21 of the container body 20 with the seaming panel 6 of the can end 1. This form of fastening of can end 1 to container body 20 is equally applicable to the first embodiment of the invention. Alternatively, other forms of fastening which are known with the field of can manufacture may be used, dependent on the specific features of the can end and container body.