METALLIC CAN AND ASSOCIATED CAN LID

Abstract

A can lid that comprises an opening region provided in the material of the lid surface and comprises a two-armed lever member that is intended to open this opening region and that is connected to the lid material, wherein this arrangement is characterized in that the opening region configured as a tongue tab is delineated from the lid surface by a tear line and the tongue tab base connected to the lid surface forms a pivot bearing that becomes effective during the opening procedure; in that the lower side of the lid is coated with a plastic material in a firmly adhering manner, and this coating of the tear line that covers the tear line is weakened in an adjacent manner; and in that the container part and the can lid at least substantially comprise the same aluminum alloy.

Claims

1.-10. (canceled)

11. A can comprising a cylindrical container part and a can lid, the can lid being sealingly connected to the cylindrical container part via a folding joint and the can lid having a bounding opening region provided in a lid material of the lid surface, and the can lid comprising a two-armed lever member intended for opening this opening region, said lever member being fixedly connected to the lid material, wherein the opening region configured as a tongue tab is delineated from the lid surface by a tear line in the form of a material weakening or of an at least partial material perforation extending over the tab periphery and with the tongue tab base connected to the lid surface forming a pivot bearing that becomes effective during the opening procedure; wherein the lower side of the lid is coated with a coating or film of plastic material in a firmly adhering manner, and this coating or film at the tear line covering the tear line and being weakened at the tear line in an adjacent manner between the tongue tab and the lid surface; and wherein the container part and the can lid at least substantially comprise the same aluminum alloy.

12. The can in accordance with claim 11, wherein the can is a beverage can.

13. The can in accordance with claim 11, wherein the lower side of the lid is coated over its full surface with the plastic material.

14. The can in accordance with claim 11, wherein the lower side of the lid is coated with a plastic film.

15. The can in accordance with claim 11, wherein the coating or film covering the tear line is weakened in a notched manner.

16. The can in accordance with claim 15, wherein the coating or film covering the tear line is at least partly notched open.

17. The can in accordance with claim 11, wherein the opening region is separated from the lid surface by a microgap extending over a tab periphery.

18. The can in accordance with claim 17, wherein the microgap is a stamped gap.

19. The can in accordance with claim 17, wherein the tongue tab of the can lid is separated from the lid surface surrounding it while forming mutually engaging projections and recesses by a cutting procedure; and wherein the tongue tab and the lid surface adjoining it are connected via the projections and the recesses in a shape-matched and force-transmitting manner while forming the microgap, with the leak-tightness of the filled and unopened can being ensured by the inwardly disposed plastic coating or film.

20. The can in accordance with claim 19, wherein the tongue tab of the can lid is separated from the lid surface surrounding it while forming the mutually engaging projections and recesses by a punching procedure.

21. The can in accordance with claim 19, wherein the coating or film of plastic material has a thickness in the range from approximately 1/10 mm to 2/10 mm.

22. The can in accordance with claim 19, wherein the projections and the recesses are coupled via undercuts.

23. The can in accordance with claim 17, wherein the lid surface is formed concavely in the region of the tongue tab and the pressing in the microgap is increased by the internal container pressure.

24. The can in accordance with claim 11, wherein the plastic film provided at the lower side of the can lid forms a separate molded blister part prior to its sealing to the lower side and a notch or a partial notching open is already provided in said molded blister part.

25. The can in accordance with claim 11, wherein the container part and the can lid comprise the same aluminum alloy and the material thickness of the can lid is substantially the same as the material thickness of the container part.

26. The can in accordance with claim 25, wherein the material thickness of the can lid does not exceed at least twice the value of the material thickness of the container part.

27. The can in accordance with claim 25, wherein the material thickness of the container part is disposed in the range of approximately 0.1 mm and less.

28. The can in accordance with claim 11, wherein an alloy of the aluminum 3000 series is used as the aluminum alloy.

29. The can in accordance with claim 18, wherein the alloy 3104 is used as the aluminum alloy.

30. A can lid comprising part of a folding joint configured to be connected to a can, the can lid further comprising a bounding opening region provided in a lid material of the lid surface, and comprising a two-armed lever member intended for opening this opening region, said lever member being fixedly connected to the lid material, wherein the opening region configured as a tongue tab is delineated from the lid surface by a tear line in the form of a material weakening or of an at least partial material perforation extending over the tab periphery and with the tongue tab base connected to the lid surface forming a pivot bearing that becomes effective during the opening procedure; wherein the lower side of the lid is coated with a coating or film of plastic material in a firmly adhering manner, and this coating or film at the tear line covering the tear line and being weakened at the tear line in an adjacent manner between the tongue tab and the lid surface; and wherein the container part and the can lid at least substantially comprise the same aluminum alloy, wherein the can lid is configured as a separate component that is designed for the subsequent leak tight connection to the can that substantially comprises the same material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The invention will be described in more detail in the following with reference to an embodiment and to the drawing; there are shown in the drawing

[0017] FIG. 1 an only sectionally and schematically shown can with a can lid configured in accordance with the invention; and

[0018] FIG. 2 a sectional representation along a diameter of the can lid in accordance with FIG. 1.

DETAILED DESCRIPTION

[0019] The representation in accordance with FIG. 1 shows an only sectionally shown container part 15 that is connected to a can lid 1 via a flange rim or folding rim 2. The can lid 1 is provided with a tear closure that can generally be of any desired known design, but preferably has one of the aspects described within the framework of this application. They can in this respect be both non-reclosable embodiments and reclosable embodiments such as are described, for example in EP 2 354 022 B1, in PCT/EP2016/057225 or in DE 10 2016 103 801.6.

[0020] Unlike known cans comprising aluminum alloys, in particular beverage cans, no aluminum alloy is used that substantially differs from the material of the container part 15 for the can lid 1 in accordance with the invention, but the same aluminum alloy is preferably used.

[0021] This is made possible by the special design of the can lid 1 and of the associated tear closure.

[0022] With conventional beverage cans of aluminum alloys, an alloy of the aluminum 3000 series is used for the container part 15, with wall thicknesses of 0.09 mm already being able to be achieved with this material as part of the always targeted weight saving. As a rule, an alloy of the aluminum 5000 series is used as the material for the can lid, with a much higher wall thickness being required in comparison with the container part to be able to realize the material notch along the tear line required for the tear closure and in this respect simultaneously to ensure the demands on the compressive strength at internal pressures of at least 6.3 bar.

[0023] It becomes possible by the design in accordance with the invention of the can lid and of the tear closure to use substantially the same aluminum alloy for the container part 15 and the can lid 1, and preferably the same aluminum alloy, namely the aluminum alloy used for the container part, in particular from the aluminum 3000 series, and preferably 3104.

[0024] This is achieved, on the one hand, by the use of a plastic coating at the inner can side ensuring the compressive strength and the leak tightness of the can and, on the other hand, by the special design of this plastic coating and its interaction with the design of the tear line in the can lid. Although this tear line is preferably configured as a microgap, it forms part of the invention to use, instead of a microgap, a tear line, that is perforated for example, or a pronounced notch that could alone not produce the required compressive strength.

[0025] FIG. 1 shows a preferred embodiment of a can 15 in accordance with the invention with a can lid 1 in a schematic plan view. The can lid is provided at its peripheral region with a bead rim 2 in a conventional manner, wherein the region disposed within the bead rim 2 is formed by a lid surface 3 that has an opening region 4 formed as a tongue tab offset with respect to the center. This can lid preferably comprising an aluminum alloy of the 3000 series is provided, surrounding the opening region 4, with a stiffening region 14 formed by material deformation. The same aluminum alloy is preferably also used for the container part 15.

[0026] A two-armed lever 5, 6 is connected, in particular riveted or welded, to the opening region 4 or to the tongue tab of the can lid such that a fixed connection point 7 results. This connection point 7 is disposed in the marginal region of the opening region 4, i.e. opposite the tongue base connected to the lid surface 3 and the two-armed lever comprises a shorter region and a longer region, wherein the longer region is preferably formed by an easily grippable ring tab 5 and the shorter region is formed by a supporting limb 6 that is supported on a part of the stiffening region 14 of the can lid on the upward pivoting of the longer lever. The two-armed lever 5, 6 lies substantially in parallel with the lid surface 3 in the starting state.

[0027] The tongue tab forming the opening region 4 is connected in a shape-matched and force-transmitting manner to the lid surface 3 via projections 12 and recesses 13 while forming a microgap 8 and preferably via suitable undercuts of these parts, and indeed with the exception of the region of the tongue base 7 where the opening region 4 and the lid surface 3 are connected in a metallic manner such that an upward pivoting of the tongue tab 4 is made possible by means of the lever practically via a kind of folding joint 9 on the opening of the can and the tongue tab and the lever can then move into a position of rest outside the inner can space while releasing the opening.

[0028] The required leak tightness or compressive strength of the can lid is ensured despite the lack of a continuous metallic connection between the lid surface 3 and the opening region 4 in the region of the toothed arrangement by a plastic material, in particular a plastic film, that is applied in particular over the whole surface, to the lower side of the metallic lid and that is attached or sealed to the lower lid side in a firmly adhering manner. The coating has a pronounced weakening 14, in particular a notch or partial opening notch, directly adjacent to and disposed within the opening line or the microgap such that on the opening of the can lid and on the pulling up of the tongue tab 4, the narrow region of the plastic film covering the microgap is practically peeled off from the material and thus an opening of the can is made possible that takes place with a small exertion of force.

[0029] To achieve this design that precludes any formation of metal splinters on the opening of the can lid, the opening region or the tongue tab is separated from the surrounding lid surface by a cutting procedure or preferably by a punching procedure on the production of the can lid, wherein the splinters or microparticles that are thereby produced can be eliminated completely and free of problems as part of the production process. The tongue tab, that is still connected via its base to the lid surface 3 is pressed back into the lid surface plane directly after its punching out such that the original appearance practically again results for the lid surface, but now with a microgap produced by the punching procedure.

[0030] Mutually engaging projections 12 and recesses 13 are preferably produced in the stamping procedure instead of a linear microgap, such as can be seen from FIG. 1.

[0031] In this case, the two initially partly separated components are again joined to one another in a shape-matched manner directly after the punching procedure such that the can lid can be handled in further production steps in the same way as conventional can lids that only have a weakening groove.

[0032] The processes of separating and joining together take place directly after one another, i.e. after the punching stroke the shape-matched joining together of both parts to form a total part takes place in the return stroke. The shape-matched and force-transmitting connection between the two regions is achieved by a suitable shaping or by using undercuts that ensures a sufficient mutual mechanical connection such that the required coating procedures or the process of the application of the film to the lower side can also be carried out as with a uniform part.

[0033] Instead of the toothed arrangement shown in the drawing, different, optionally simpler, gap line extents can be provided in accordance with the invention in the punching procedure, wherein, however, the opening region or the tongue tab in every case remains connected to the lid surface 3 via the pivot bearing region 9 and the microgap is covered by the plastic film disposed at the inner side and provided with a notch. The plastic film, which can be an PP film and which reacts to the sealing wax provided at the metal during sealing, is in particular manufactured as a separate molded blister part in which the notch is already provided. If the film has a thickness e.g. of approximately 2/10 mm, a weakening to 1/100 mm takes place in the notch.

[0034] The somewhat enlarged part representation in accordance with FIG. 2 above all shows, in addition to the embodiment of the connection point 7 in the manner of a rivet connection, the application of the plastic film 10 over the full surface to the lower side of the can lid and in particular the formation of the weakening line 11 in the plastic film 10 preferably achieved by a notching and/or regionally by a notching open, said plastic film extending within or outside the microgap about the opening region 4 depending on the embodiment, with the spacing between the weakening line and the microgap being dimensioned such that, on the one hand, the demands on the compressive strength of the can are satisfied and, on the other hand, the already mentioned peeling effect results during the opening procedure.

[0035] Since, unlike with known can lids, no special demands have to be made on the aluminum alloy material of the can lid 1 in connection with notches producing material weakening and with compressive strength, the same aluminum alloy can practically be used with preferably the same material thickness both for the container part and for the can lid. No special, in particular high-quality, alloy material such as an alloy of the aluminum 5000 series thus also has to be used in the can production, which produces simplifications and above all cost savings since the same recycling material can thus be used for the entire can.

REFERENCE NUMERAL LIST

[0036] 1 can lid [0037] 2 bead rim [0038] 3 lid surface [0039] 4 opening region, tongue tab [0040] 5 lever arm [0041] 6 lever arm [0042] 7 fastening point, tongue base [0043] 8 microgap [0044] 9 pivot bearing region [0045] 10 plastic film [0046] 11 weakening line, notch [0047] 12 projection [0048] 13 recess [0049] 14 stiffening region [0050] 15 container part