LID FOR AN ALUMINUM BEVERAGE CAN

Abstract

The invention refers to a can lid for an aluminum beverage can. The can lid has a pull tab, a chuck wall defining a plug diameter, a countersink and central panel having a panel radius. On the central panel, a score line defining a tear panel and a rivet for connecting a pull tab to the can lid are arranged. The rivet extends through a rivet island that is arranged between an opening part of the pull tab and a handle part of the pull tab. The lid has lid plug diameter of between 45 to 49 mm, an outside diameter of between 52 to 55 mm and a weight of less than 1.9 grams. The central panel has a thickness of less than 0.19 mm. The score line defines an area of between 300 mm.sup.2 to 350 mm.sup.2 and the score line has a shortest distance from the panel radius of less than 3 mm.

Claims

1. A beverage can, comprising: a body that is symmetric about a longitudinal axis and comprises: a base end with a stand ring and a dome; a sidewall extending upwardly from the base end; and a neck; and a can lid interconnected to an upper end of the neck by a seam, the can lid comprising: a chuck wall extending downwardly from the seam; a countersink at a lower portion of the chuck wall; and a center panel interconnected to an inner portion of the countersink, the center panel comprising a panel radius, a score line defining a tear panel, a rivet, a pull tab interconnected to the center panel by the rivet, and a ramp-up bead configured to elevate a grip end of the pull tab away from the center panel as the pull tab is rotated from a stored position to an opening position, wherein the ramp-up bead has an arcuate shape and is positioned substantially parallel to a perimeter of the center panel, and wherein a distance between an outermost portion of the score line and the panel radius is less than approximately 3 mm.

2. The beverage can of claim 1, wherein the distance between the outermost portion of the score line and the panel radius of the center panel is less than approximately 1 mm.

3. The beverage can of claim 1, wherein the tear panel has an area of between approximately 24% to approximately 34% of an area of the center panel.

4. The beverage can of claim 1, wherein the pull tab is configured to rotate around the rivet from the stored position with an opening end rotated away from the tear panel to the opening position with the opening end positioned above the tear panel and with the grip end of the pull tab spaced from the center panel.

5. The beverage can of claim 1, wherein the rivet is tilted at an angle of between approximately 1° and 9° with respect to a line normal to a plane defined by the countersink.

6. The beverage can of claim 1, wherein the pull tab has a rivet island affixed to the rivet, wherein the rivet island defines a plane that is tilted at an angle of between approximately 2° and approximately 4° with respect to a plane defined by the countersink.

7. The beverage can of claim 1, further comprising a background penetration formed in the center panel that is configured to lower a tensile strength of the score line.

8. The beverage can of claim 7, wherein the background penetration is positioned along both sides of the score line.

9. The beverage can of claim 7, wherein the background penetration further comprises a first width and a first depth, and wherein the first width is greater than a widest portion of the score line and the first depth is less than a maximum depth of the score line.

10. The beverage can of claim 1, wherein a diameter of the center panel is not greater than approximately 40 mm.

11. The beverage can of claim 1, wherein the rivet is arranged at or near a center of the center panel.

12. The beverage can of claim 1, wherein an area of the tear panel is less than approximately 350 mm.sup.2.

13. The beverage can of claim 1, wherein the can lid is made from an aluminum or a steel.

14. The beverage can of claim 1, wherein the center panel has a first axis defined by the rivet and a center of the tear panel, and wherein the outermost portion of the score line is offset from the first axis.

15. The beverage can of claim 14, wherein the distance between the outermost portion of the score line and the panel radius is less than approximately 1.1 mm.

16. The beverage can of claim 14, wherein a distance between the score line and the panel radius at the first axis is approximately 1.41 mm.

17. The beverage can of claim 14, wherein the center panel has a second axis that is perpendicular to the first axis defined by the rivet and the center of the tear panel and the second axis extends through the rivet, and wherein on one side of the first axis the score line extends from a first side of the second axis to a second side of the second axis to improve pouring.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and other aspects, features and advantages of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein:

[0026] FIG. 1 is a side-elevated perspective view of a seamed two-piece beverage can according to the invention;

[0027] FIG. 2 is a cross-sectional view of a seamed two-piece beverage can along the can's longitudinal axis;

[0028] FIG. 3 is a cross-sectional view of a can body prior to seaming;

[0029] FIG. 4 is a cross-sectional view of a can lid prior to seaming;

[0030] FIG. 5 is a top-level view of a first embodiment of a can lid according to the invention;

[0031] FIG. 6 is a top-level view of a second, alternative embodiment of a can lid according to the invention;

[0032] FIG. 7 is a top-level view of a third alternative embodiment of a can lid according to the invention;

[0033] FIG. 8 is a cross-sectional view of an alternative can lid having a tilted rivet prior to seaming;

[0034] FIG. 9A is a top-level view of a fourth alternative embodiment of a can lid having a pull tab that initially is orientated at an offset-angle with respect to an axis of symmetry defined by the rivet and the tear panel and further having ramp-up beads arranged on either side of the pull tab that assist lifting the pull tab when the pull tab is rotated around an axis of rotation defined by the rivet;

[0035] FIG. 9B is an expanded view of a ramp-up bead of FIG. 9A;

[0036] FIG. 10 shows a can lid according to FIG. 9A with the pull tab rotated in its opening position;

[0037] FIG. 11A shows details of a first variant of the score line;

[0038] FIG. 11B shows a cross-sectional view of the score line of FIG. 11A along line A-A;

[0039] FIG. 12A shows details of a second variant of the score line; and

[0040] FIG. 12B shows a cross-sectional view of the score line of FIG. 12A along line B-B.

DETAILED DESCRIPTION

[0041] The following description is of the best mode presently contemplated for carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of describing the general principles of the invention. The scope of the invention should be determined with reference to the claims.

[0042] FIG. 1 shows a two piece aluminum beverage can 10 according to the invention. The can comprises a can body 12 and a can lid 14 seamed to the can body. The can body 12 is a unitary DWI (drawn and wall-ironed) can body and the can lid 14 has a pull tab 38.

[0043] The can body 12 is formed from a single piece of aluminum sheet metal (blank) and has a base 16, a cylindrical sidewall 18 and a neck 20. The base 16 has a standing ring 22 and a dome 24. The can body 12 is preferably made from aluminum, in particular from series 3000 aluminum.

[0044] The can lid 14 has a chuck wall 26, a countersink 28 and a central panel 30. In the central panel, a tear panel 32 is provided which is defined by a score line 34. Next to the tear panel, a material absorption bead may be arranged. Pull tab 38 is affixed to the central panel 30 by means of a rivet 40. A central section of the pull tab 38 is a rivet island 50 that is fixated to the central panel 30 by means of the rivet 40. Typically, the pull tab 38 can be rotated about the rivet 40 if a certain force is applied. The axis of rotation is perpendicular with respect to a plane defined by the rivet island 50. The pull tab 38 has a handle part 42 to be gripped by a user's finger and an opening part 44 that is pressed against the tear panel 32 if the handle part 42 is lifted by a user. Thus, the pull tab 38 serves to rupture the score line 34 in order to open the beverage can 10 in a known manner. The tear panel 32 thus defines the dimensions of the opening created by lifting the handle part of the pull tab 38. The tear panel defines an opening—for instance a drinking opening—having an area of between 300 mm.sup.2 to 350 mm.sup.2 after opening the beverage can.

[0045] The can lid 14 is fixed to the can body 12 by means of a folded double seam 41. The seam 41 has a diameter of between 46 mm and 49 mm.

[0046] The diameter L of the seam 41 (illustrated in FIG. 2) is approximately 48 mm. The diameter J of the stand ring 22 (illustrated in FIG. 3) is smaller than the diameter L of the seam 41. Therefore, beverage cans can be stacked upon one another, so that the stand ring of the upper can protrudes into the space within the seam 41. Alternatively, the stand ring may have a larger diameter than the seam.

[0047] The can body 12 has a can body plug diameter of between 45 to 49 mm and a weight below 9.3 g for a 330 ml can, and below 9.7 g for a 355 ml can.

[0048] The can lid 14 has a can plug fitting diameter of between 45 to 49 mm, an outside diameter of between 52 to 55 mm, a central panel with a thickness of less than 0.19 mm, e.g. 0.183 mm, and a weight of less than 1.9 g.

[0049] FIG. 2 is a cross-sectional view of the can 10 with the can lid 14 seamed to the can body 12. In the cross-sectional view, the chuck wall 26 and the countersink 28 of the can lid 14 can be seen as well as the cylindrical sidewall 18, the neck 20, the stand ring 22 and the dome 24 of the can body 12.

[0050] Referring to FIG. 3, the diameter A of the can is between 56 mm and 59 mm, for instance approximately 58 mm. The can diameter A corresponds to the diameter of the cylindrical sidewall 18. As further can be taken from FIG. 3, the base 16 extends along a height F of about 5 to 10 mm. The cylindrical sidewall 18 has a height G of about 120 mm. The neck 20 has a height H of about 17 mm. The can body 12 is symmetric about a longitudinal axis 46. Prior to sealing, the can body 12 has an upper open end with an inner diameter B, which is called plug diameter, and which is about 46 mm.

[0051] Can body 12 is produced by a draw and wall ironing process (DWI), wherein first a cup is formed and then the sidewall is formed by drawing and wall ironing. Thereafter, the neck 20 is formed in a necking machine (necker) to achieve an upper can end that has a smaller diameter than the maximum can diameter. The ratio of the plug diameter B to can diameter A is called the necking ratio. The necking ratio of the can body 12 of the embodiment of FIG. 3 is a little less than 80%.

[0052] The can body 12 is drawn from a single piece of aluminum sheet metal, having a gauge of 242 μm. Therefore, the wall thickness in the middle of the dome 24 is approximately 240 μm.

[0053] The maximum wall thickness of the can in the middle of the dome 24 of the base 16 is between 235 μm and 245 μm, such as 240 μm or 242 μm. The tool for drawing and wall ironing preferably is configured to create a transitional wall thickness from the base to the sidewall in two steps. The tool preferably provides a first step with an angle of 1° and a second step with an angle of ˜30°. Thus, the wall thickness of the can body is reduced from about 240 μm in the area of the base to about 79 μm at the middle part of the sidewall 18.

[0054] The wall thickness of the middle part of the neck is about 111 μm. The neck has a flange (at its upper end) having a wall thickness in the range of between 130 μm and 150 μm, for instance 140 μm.

[0055] The transition from the sidewall 18 to the neck 20 is rounded. The radius in the transition from the sidewall 18 to the neck 20 is between 10 mm and 20 mm, for instance 15 mm. Such a transition is also called “round shoulder”.

[0056] The angle of the neck 20 relative to the sidewall 18 of a central longitudinal axis 46 of can the body 12 is between 25° and 35°, for instance 30°.

[0057] The beverage can 10 has a nominal volume of between 330 ml and 355 ml and a height E of between approximately 145 mm and 147 mm for a 330 ml can and a height E of between 156 mm and 159 mm for a 355 ml can.

[0058] A can body according to the embodiments of the Figures has a weight below 9.3 g for a can with a nominal volume of 330 ml and below 9.7 g for a can having a nominal volume of 355 ml.

[0059] The total internal volume of the seamed can is the nominal volume plus a head space. The volume of the head space is little less than 20 ml, for instance 18 ml. Thus, a can with a nominal volume of 330 ml has a total internal volume of 348 ml, and a can with a nominal volume of 355 ml has a total internal volume of 373 ml.

[0060] FIG. 4 is a cross-sectional view of can lid 14 prior to seaming illustrating the outside diameter (curl diameter) K. FIG. 4 further illustrates a can lid plug diameter R that is defined by the chuck wall 26 and a central panel diameter Q of the central panel 30.

[0061] FIG. 5 is a top-level view of a first embodiment of a can lid according to the invention. The can lid 14 as illustrated in FIG. 5 has a curl diameter K of 53.31 mm, a can lid plug diameter R of 45.4 mm and central panel diameter Q of 37.55 mm. As can be taken from FIG. 5, on a central panel 30, a central rivet 40 is arranged that connects a rivet island 50 of the pull tab 38 to the central panel 30. The rivet island 50 is an integral part of the pull tab 38 and forms a bendable hinge between a handle part 42 of the pull tab 38 and an opening part 44 of pull tab 38. An outer pull tab curl 54 of the pull tab 38 provides for sufficient stiffness between the handle part 42 and the opening part 44 so that the opening part 44 can exert a strong enough force on the tear panel 32 when the handle part 42 of the pull tab 38 is lifted.

[0062] The tear panel 32 is defined by a score line 34 and has an area of 331 mm.sup.2 and has a shark fin design featuring a triangular extension 56 next to the rivet that improves pouring because it eases entering of air in the can. The closest distance between a panel radius 48 and the score line 34 of the embodiment of the can lid 14 as shown in FIG. 5 is 1.1 mm at a location indicated by arrows 35. The can lid 14 is made from pre-coated aluminum sheet metal.

[0063] FIG. 6 is a top-level view of a second, alternative embodiment of a can lid 14′. The embodiment of the can lid 14′ as illustrated in FIG. 6 differs from can lid 14 as illustrated in FIG. 5 only by the shape of tear panel 32′ that is defined by a score line 34′. The area of the tear panel 32′ is 334.2 mm.sup.2. The closest distance between the score line 34′ and the panel radius 48 is 0.99 mm at a point indicated by arrows 35′. The distance between score line 34′ and panel radius 48 at the apex of score line 34′ is 1.41 mm. The apex of the score line is located on the axis of symmetry defined by the rivet 40 and the tear panel 32′ and is indicated by arrows 37.

[0064] FIG. 7 is a top-level view of a can lid 14″ similar to the can lid 14 of FIG. 5 or can lid 14′ of FIG. 6 that features two material absorption beads 36 that are symmetrically arranged on both sides of the pull tab 38 and the tear panel 32. The two material absorption beads 36 are separated by a bead gap where the tear panel comes closest to the panel radius, e.g. at a score line apex. That means, no material absorption bead is provided where the tear panel 32 comes closest to the panel radius 48.

[0065] In order to improve the accessibility of the handle part 42 of the pull tab 38, the rivet 40 may be tilted as shown in FIG. 8. The axis of rotation defined by the rivet 40 is tilted with respect a normal to a plane defined by the countersink 28. Likewise the plane defined by the rivet island 50 has a tilt angle with respect to the plane defined by the countersink 28. The tilt angle is between 2° and 4°, for instance 3°.

[0066] Additionally or alternatively the can lid 14 can have a pull tab that initially is orientated at an offset-angle with respect to an axis of symmetry defined by the rivet and the tear panel as shown in FIG. 9A. In such embodiment, the pull tab 38 first must be aligned with the tear panel 32 in order to allow opening of the tear panel 32. Aligning of the pull tab 38 requires a rotation of the pull tab 38 that can help to lift the handle part 42 of the pull tab 38 so that the handle part 42 can be gripped easier.

[0067] Lifting of the handle part 42 of the pull tab 38 can be facilitated by ramp-up beads 58 arranged on either side of the pull tab 38; see FIG. 9A. Ramp-up beads 58 assist lifting the pull tab when the pull tab is rotated around an axis of rotation defined by the rivet.

[0068] The ramp-up beads 58 define a gap 52 between them that provides a click-in effect when the pull tab is aligned in its opening position as illustrated in FIG. 10. Thus, the ramp-up beads 58 provide a tactile feedback to a user that helps the user to correctly orientate the pull tab 38 for opening the tear panel 32. Accordingly, the ramp-up beads 58 also serve as orientation beads.

[0069] FIGS. 11A and 11B and 12A and 12B show cross-sections of alternative embodiments of score line 34 or 34′, respectively. In the embodiment shown in FIGS. 11A and 11B, an anti fracture score 60 is provided that runs in parallel to score line 34. FIG. 11B shows a cross section of the score line taken along line A-A of FIG. 11A. The anti fracture score 60 has the effect to lower the tensile stress near the deepest portion of the score line 34 and thus avoids an unwanted fracture of the score line prior to intended opening of the tear panel 32.

[0070] In the alternative embodiment shown in FIGS. 12A and 12B, a background penetration 62 is provided that runs along the score line 34′. Similar to the anti fracture score 60 of FIGS. 11A and 11B, the background penetration 62 has the effect to lower the tensile stress near the deepest portion of score line 34′ and thus avoids an unwanted fracture of the score line prior to intended opening of the tear panel 32. FIG. 12B shows a cross section of the score of FIG. 12A taken along line B-B.

LIST OF REFERENCE NUMERALS

[0071] 10 Can [0072] 12 Can body [0073] 14 Can lid [0074] 16 Base [0075] 18 Sidewall [0076] 20 Neck [0077] 22 Stand ring [0078] 24 Dome [0079] 26 Chuck wall [0080] 28 Countersink [0081] 30 Central panel [0082] 32 Tear panel [0083] 34 Score line [0084] 35 Arrow indicating closest distance between panel radius and the score line [0085] 36 Absorption bead [0086] 37 Arrow indicated apex of score line [0087] 38 Pull Tab [0088] 40 Rivet [0089] 41 Double Seam [0090] 42 Handle part [0091] 44 Opening part [0092] 46 Longitudinal axis of can body [0093] 48 Panel radius [0094] 50 Rivet island [0095] 52 Gap [0096] 54 Pull tab curl [0097] 56 Triangular extension (shark fin) [0098] 58 Ramp-up bead [0099] 60 Anti fracture score [0100] 62 Background penetration [0101] A Maximum diameter [0102] B Plug diameter [0103] E Can height [0104] F Base height [0105] G Cylindrical sidewall height [0106] H Neck height [0107] J Stand ring diameter [0108] K Curl diameter [0109] L Seam diameter [0110] Q Central panel diameter [0111] R Can lid plug diameter