WO2013044095A1

WO2013044095A1 - Stay-on tab for a beverage container

Info

Publication number: WO2013044095A1
Application number: PCT/US2012/056662
Authority: WO
Inventors: Randall G. Forrest
Original assignee: Rexam Beverage Can Company
Priority date: 2011-09-23
Filing date: 2012-09-21
Publication date: 2013-03-28
Also published as: MX2014003441A; MX350328B; EP2758192A1; BR112014006711A2; US20130075401A1

Abstract

A non-detachable pull tab (26) for a beverage container has a nose end (30), a lift end (32) opposite the nose end (30), and a central webbing (42) of a metallic material between the nose and lift end (32). The central webbing (42) has a hinge region (44), a rivet island (46) surrounding a rivet hole, a void region at least partially surrounding the rivet island (46), and a grab portion (54) between the first void region and the lift end (32). The grab portion (54) has an upper surface, a lower surface, and an aperture therethrough. The aperture is defined by a circumferential wall (80) of the grab portion (54) extending from the upper surface to the lower surface and includes a first segment (92) of a reworked portion of a burr (90).

Description

STAY-ON TAB FOR A BEVERAGE CONTAINER

DESCRIPTION

TECHNICAL FIELD

[0001] The invention relates to beverage containers. More particularly, the invention relates to stay-on or non-detachable tabs for beverage can lids having an indicium pierced therethrough.

BACKGROUND OF THE INVENTION

[0002] Typical end closures for beer and beverage containers have an opening panel and an attached leverage tab for pushing the opening panel into the container to open the end. The container is typically a drawn and ironed metal can, usually constructed from a thin plate of aluminum or steel. End closures for such containers are also typically constructed from a cutedge of thin plate of aluminum, formed into a blank end, and manufactured into a finished end by a process often referred to as end conversion. These ends are formed in the process of first forming a cutedge of thin metal, forming a blank end from the cutedge, and converting the blank into an end closure which may be seamed onto a container.

[0003] These types of container ends have been used for many years, with almost all such ends in use today being the "ecology" or "stay-on-tab" ("SOT") ends in which the tab remains attached to the end after a tear panel, including large-opening ends ("LOE"), is opened. The tear panel being a portion of the can end defined by a score length. The tear panel may be opened, that is the score may be severed, and the tear panel displaced at an angular orientation relative to the remaining portion of the can end. The tear panel remains hingeably connected to the remaining portion of the can end by a hinge segment, leaving an opening through which the user draws the contents of the container. In an LOE, the opening is at least 0.5 square inches in area.

[0004] Opening of the tear panel is operated by the tab which is attached to the can end by a rivet. The tab is attached to the can end such that a nose of the tab extends over a proximal portion of the tear panel. A lift end of the tab is located opposite the tab nose and provides access for a user to lift the lift end, such as with the user's finger, to force the nose against the proximal portion of the tear panel.

[0005] When the tab nose is forced against the tear panel, the score initially ruptures at a vent region of the score. This initial rupture of the score is primarily caused by the lifting force on the tab resulting in lifting of a central region of the can end, immediately adjacent the rivet. As the tab is lifted further, the score rupture propagates along the length of the score, eventually stopping at the hinge segment.

[0006] Tabs are often also used to convey information to users. This information may be in the form of promotional materials, logos, or the like. Methods such as printing, incising, laser ablation, stamping, etc. have been employed to provide information on the tabs. To date, none of these methods has been widely accepted.

[0007] Some publications dedicated to methods of conveying information to a user in conjunction with beverage containers include: U.S. Publication No. 2006/0151501 which discloses a protective sanitary film for coating a can lid; U.S. Patent No. 1,257,710 which describes a crimped bottle cap; U.S. Patent No. 4,380,129 which described information- bearing tabs; U.S. Patent No. 1,878,541 which describes an impressed cap; U.S. Patent No. 4,203,240 which describes placing indicia on a beverage container; U.S. Patent No.

4,459,910 which describes an embossing machine having upper tooling including multiple embossing stamps and lower tooling including an anvil only; U.S. Patent No. 4,557,505 which discloses tamper evident tape; U.S. Patent No. 5,191,695 which discloses a token which is insertable into the finger hole of a tab, which token may be marked by molding, embossing, hot die stamping, or ink jet printing where embossing is used only when thickness of tab is so great that indicia will not show through; U.S. Patent No. 5,316,166 which is similar to U.S. Patent Nos. 5,191,695; US-6,080,958, 6,433,302, 6,501,046, 6,706,995 and 6,498,318 which describe marking tabs with embossing via stamping or incising; U.S. Patent No. 6,105,806 which is primarily dedicated to a laser etched image on a tab; U.S. Patent No. 6,202,880 which discloses a second score having a shape and laser markings; U.S. Patent No. 6,777,098 which discloses laser marking an anodized aluminum; and U.S. Patent No.

6,868,627 which describes indicia on a tab which indicia may consist of a mark, shape, depression, cut, mold, impression.

[0008] Other publications which may be relevant to providing indicia on non-detachable tabs include AU-784218, DE-19701547, DE-29716186, EP-0923457, GB-2105257, JP- 3146174, WO-00/03832, WO-01/68460, WO-98/10945, and WO-99/09853.

[0009] Co-pending and commonly assigned U.S. Application No. 12/363,696 also describes methods of decorating and strengthening can end tabs. [0010] Co-pending and commonly assigned U.S. Application No. 12/727,873 is directed to temperature indicating means which may be located on a can end tab.

[0011] The present invention is provided to solve the problems discussed above and other problems, and to provide advantages and aspects not provided by prior tabs of this type. A full discussion of the features and advantages of the present invention is deferred to the following detailed description, which proceeds with reference to the accompanying drawings.

SUMMARY OF THE INVENTION

[0012] One aspect of the present invention is directed to a non-detachable pull tab for a beverage container. The tab comprises a nose end, a lift end opposite the nose end, and a central webbing of a metallic material between the nose and lift end. The central webbing comprises a hinge region, a rivet island surrounding a rivet hole wherein the rivet island is at least partially surrounded by a first void region; and a grab portion between the first void region and the lift end. The grab portion has an upper surface and a lower surface and an aperture therethrough. The aperture is defined by a circumferential wall of the grab portion extending from the upper surface to the lower surface and comprising a first segment of a reworked portion of a burr.

[0013] This aspect of the invention may include one or more of the following features, alone or in any reasonable combination. The reworked portion of the burr may be located adjacent the lower surface of the grab portion. A second segment of the reworked portion of the burr may be located radially outwardly from the first segment of the reworked portion of the burr. The circumferential wall may comprise a burnished section located adjacent the upper surface of the grab portion. The circumferential wall may comprise a fractured section located adjacent the burnished section. The aperture may be in a form of an indicium to convey information to a user. The reworked portion of the burr may be flattened relative to the lower surface of the grab portion. The reworked portion of the burr may be flattened against the lower surface of the grab portion.

[0014] Another aspect of the present invention is directed to a non-detachable pull tab for a beverage container. The tab comprises a nose end, a lift end opposite the nose end, and a central webbing of a metallic material between the nose and lift end. The central webbing comprises a hinge region, a rivet island surrounding a rivet hole wherein the rivet island is at least partially surrounded by a first void region, and a grab portion comprising an indicium. The indicium comprises an aperture at least partially defined by a wall of a pierced segment of the metallic material extending from the upper surface to the lower surface of the grab portion. The wall comprises a fractured portion of the metallic material and a reworked portion of a burr located at least partially about the aperture. The reworked portion comprises a flattened segment. The reworked portion of the burr may be located adjacent the lower surface of the grab portion.

[0015] Another aspect of the present invention is directed to an apparatus for forming a non-detachable tab. The apparatus comprises a first tool having a piercing surface in a shape to form an indicium, a second tool in operable alignment with the first tool having an opening complimentary to the piercing shape of the first tool for receiving the piercing surface therein, a third tool having a shape retaining surface similar to the piercing surface, and a fourth tool in operable alignment with the third tool.

[0016] This aspect of the invention may include one or more of the following features, alone or in any reasonable combination. The piercing surface of the first tool may have a sharp edge defining a perimeter of the piercing surface. The retaining surface may have an edge defining a perimeter of an upper surface of the third tool having a radius of curvature greater than a radius of curvature of the sharp edge of the piercing surface. The fourth tool may have an opening for receiving the retaining surface of the third tool. The fourth tool may have a relatively flat engagement surface about the opening.

[0017] Another aspect of the present invention is directed to a method for forming a non- detachable tab. The method comprises the steps of: (1) providing a sheet of a metallic material; (2) a first tool having a piercing surface in a shape to form an indicium; (3) a second tool in operable alignment with the first tool having an opening complimentary to the piercing shape of the first tool; (4) passing the sheet of metallic material between the first and second tools; (5) forming an indicium on the sheet of metallic material by piercing the sheet of metallic material through relative movement between the first and second tools; (6) providing a third tool; (7) providing a fourth tool in operable alignment with the third tool; (8) passing the indicium between the third and fourth tools; and (9) reworking a burr created in the forming an indicium step by providing relative movement between the third and fourth tools.

[0018] This aspect of the invention may include one or more of the following features, alone or in any reasonable combination. The third tool may have a retaining surface having similar shape to the piercing surface on the first tool. The method may comprise the step of inserting the retaining surface within the indicium pierced in the sheet of metallic material. The method may further comprise the step of inserting the retaining surface within the indicium pierced in the sheet of metallic material and into an opening in the fourth tool wherein the opening has a circumferential perimeter similarly shaped to a circumferential shape of the retaining surface.

[0019] Another aspect of the present invention is directed to a non-detachable pull tab for a beverage container. The tab comprises a nose end, a lift end opposite the nose end, and a central webbing of a metallic material between the nose and lift end. The central webbing comprises a hinge region, a rivet island surrounding a rivet hole, the rivet island being at least partially surrounded by a first void region, and a grab portion between the first void region and the lift end. The grab portion has an upper surface and a lower surface and an indicium in the form of an aperture having a perimeter at least partially defined by a reworked portion of the metallic material.

[0020] This aspect of the invention may include one or more of the following features, alone or in any reasonable combination. The reworked portion of the metallic material may comprise a flattened segment engaging the lower surface of the grab portion. The tab may further comprise a circumferential wall defining a portion of the aperture between the upper surface and the lower surface of the grab portion wherein the circumferential wall comprises a first portion of a burnish depth, a second portion of a fracture depth, and a portion of the burr. The central webbing may further comprise a void region partially surrounding the rivet island. The grab portion may further comprise a recessed panel between the lift end and the void region wherein the indicium is located within the recessed panel. A radially outermost portion of the reworked portion of the burr may be located radially outwardly of the circumferential wall relative to a central vertical axis of the grab portion.

[0021] Other features and advantages of the invention will be apparent from the following specification taken in conjunction with the following drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] To understand the present invention, it will now be described by way of example, with reference to the accompanying drawings in which: [0023] FIG. 1 is top view of a can end, lid or closure having stay-on, ecology, or non- detachable opening system featuring a tab riveted to a central panel;

[0024] FIG. 2 is a top view of a non-detachable tab;

[0025] FIG. 3 is a bottom view of the non-detachable tab of FIG. 2;

[0026] FIG. 4 is a cross-sectional view of the non-detachable tab of FIG. 2;

[0027] FIG. 5 is a top view of a forming progression of a tab of the present invention;

[0028] FIG. 6 is an alternative forming progression of a tab of the present invention;

[0029] FIG. 7 is a partial cross-sectional schematic view of a partially pierced segment of a tab of the present invention, including tooling for forming an indicium;

[0030] FIG. 8 is a partial cross-sectional schematic view of a pierced surface of a tab of the present invention;

[0031] FIG. 9 is a partial cross-sectional schematic view of a pierced segment of a tab of the present invention undergoing a reworking process according to the present invention;

[0032] FIG. 10 is a partial cross-sectional schematic view of a pierced segment of a tab of the present invention undergoing a reworking process according to the present invention; and

[0033] FIG. 11 is a partial cross-sectional schematic view of the pierced segment of the completely formed tab.

DETAILED DESCRIPTION

[0034] While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated.

[0035] The present invention is generally related to can ends or lids for a two-piece beverage can typically produced from a metallic material. Referring to the FIG. 1, an end closure 10 for a container (not shown) has a central panel wall 12 having a seaming curl 14 for joining the end closure 10 to the container. The container is typically a drawn and ironed metal can, usually constructed from a thin plate of aluminum or steel. End closures for such containers are also typically constructed from a cutedge of thin plate of aluminum or steel, formed into blank end, and manufactured into a finished end by a process often referred to as end conversion. In the embodiments shown in the figures, the central panel 12 is joined to a container by a seaming curl 14 which is joined to a mating curl of the container. The seaming curl 14 of the end closure 10 is integral with the central panel 12 by a downwardly extending wall 15 and a strengthening member 16, typically either a countersink or a fold, which is joined to the panel outer edge 18 of the central panel 12. This type of means for joining the central panel 12 to a container is presently the typical means for joining used in the industry, and the structure described above is formed in the process of forming the blank end from a cutedge of metal plate, prior to the end conversion process. However, other means for joining the central panel to a container may be employed with the present invention.

[0036] The steps of manufacturing the end 10 begin with blanking the cutedge, typically a round or non-round cutedge of thin metal plate. Examples of non-round cutedge blanks include elliptical cutedges, convoluted cut edges, and harmonic cut edges. A convoluted cutedge may be described as generally having three distinct diameters, each diameter being 45° relative to the others. The cutedge is then formed into a blank end by forming the seaming curl, countersink, panel radius and the central panel.

[0037] A means for opening the can end or accessing the contents of the container is typically formed in a conversion process for this type of end closure. This process includes the following steps: forming a rivet by first forming a projecting bubble in the center of the panel and subsequently working the metal of the bubble into a button and into the more narrow projection of metal being the rivet; forming the tear panel by scoring the metal of the panel wall; forming an inner bead or panel on the tear panel; forming a deboss panel by bending the metal of the panel wall such that a central area of the panel wall is slightly lower than the remaining panel wall; staking the tab to the rivet; and other subsequent operations such as wipe-down steps to remove sharp edges of the tab, lettering on the panel wall by scoring, incising, or embossing (or debossing), and restriking the rivet island.

[0038] The central panel wall 12 is generally centered about a longitudinal axis and has a displaceable tear panel 20 defined by a frangible score 22 and a non- frangible hinge segment. The tear panel 20 of the central panel 12 may be opened, that is the frangible score 22 may be severed and the tear panel 20 displaced at an angular orientation relative to the remaining portion of the central panel 12, while the tear panel 20 remains hinged to the central panel 12 through the hinge segment. In this opening operation, the tear panel 20 is displaced at an angular deflection. More specifically, the tear panel 20 is deflected at an angle relative to the plane of the panel 12, with the vortex of the angular displacement being the hinge segment.

[0039] The tear panel 20 is formed during the conversion process by a scoring operation. The tools for scoring the tear panel 20 in the central panel 12 include an upper die on a public side 34 having a scoring knife edge in the shape of the tear panel 20, and a lower die on a product side to support the metal in the regions being scored. When the upper and lower dies are brought together, the metal of the panel wall 12 is scored between the dies. This results in the scoring knife edge being embedded into the metal of the panel wall 12, forming the score which appears as a wedge-shaped recess in the metal. The metal remaining below the wedge- shaped recess is the residual of the score 22. Therefore, the score is formed by the scoring knife edge causing movement of metal, such that the imprint of the scoring knife edge is made in the public side 34 of the panel wall 12.

[0040] The central panel 12 further includes a tab 26. As shown in FIG. 2, the tab 26 has a generally elongated body with a central axis A-A defined by a central cross section through the tab nose 30, and through a central webbing 42 and the lift end 32. Typical prior art container ends often have a tab 26 which is staked in the final steps of the conversion process by staking the area of the panel wall 12 adjacent and under the rivet island 46 at an angle, to bias the tab 26 such that the lift end 32 of the tab 26 rests close to the panel wall 12. The central panel 12 may also have a recess near the lift end 32 of the tab 26 to allow for easier finger access.

[0041] The opening of the tear panel 20 is operated by the tab 26 which is attached to the central panel 12 by a rivet 28, generally through a rivet hole 29. The tab 26 is attached to the central panel 12 such that the nose 30 of the tab 26 extends over a proximal portion of the tear panel 20. The lift end 32 of the tab 26 is located opposite the tab nose 30 and provides access for a user to lift the lift end 32, such as with the user's finger, to force the nose 30 against the proximal portion of the tear panel 20.

[0042] When the tab nose 30 is forced against the tear panel 20, the score 22 initially ruptures at the vent region of the score 22 of the tear panel 20. This initial rupture of the score 22 is primarily caused by the lifting force on the tab resulting in lifting of a central region of the center panel, immediately adjacent the rivet 28, which causes separation of the residual metal of the score 22. The force required to rupture the score in the vent region, typically referred to as the "pop" force, is a lower degree of force relative to the force required to propagate other regions of the score 22 by continued lifting of the lift end 32 of the tab 26. Therefore, it is preferable for the panel 12 in the area around the rivet 28 only lifts enough to assist with initial score rupture, or "pop," and remains substantially stiff and flat to provide the needed leverage for the tab 26 to propagate the scoreline of the tear panel 20. The present invention provides such optimal stiffness in the center panel, as is explained further below.

[0043] After the initial "pop", or venting of the tear panel, the user continues to lift the lift end 32 of the tab 26 which causes the tab nose 30 to be pushed downward on the tear panel 20 to continue the rupture of the score 22, as an opening force. As the opening operation is continued, the tear panel 20 is displaced downward and is rotated about the hinge region to be deflected into the container.

[0044] Referring to FIGS. 2-4, the tab 26 has a central webbing 42 located between the nose 30 and the lift end 32. The central webbing 42 includes a hinge region 44 and a rivet island 46 surrounding the rivet 28. An opening or void region 48 of the tab webbing 42 may provide an exposed area of the central panel 12. The void region 48 has a curvilinear geometry which borders the rivet island 46 and at least partially surrounds the rivet 28, with a first end of the void region 48 being disposed generally to one side of the rivet 28, and a second end being generally disposed on an opposite side of the rivet 28. The hinge region 44 of the tab webbing 42 includes a hinge line which is defined by a substantially straight line passing between the first end and the second end of the void region 48. It may also be necessary to add material to the tab webbing 42, modify the radius of the curl, add beading, or other strengthening means to ensure that this area is strong enough wherein the tab 26 bends at the hinge region 44 during opening.

[0045] The void region 48 is within the tab webbing 42. The void region 48 may have a generally arch-shaped configuration. In this configuration, the rivet island 46 again follows the general shape of the void region 48. Alternatively, the void region 48 may be no more than a slit or cut through the central webbing 42.

[0046] The figures represent only one example of the rivet island 46 configuration.

However, those individuals who are ordinary skilled in the art would understand that the rivet island 46 and the void region 48 can take any number of shapes without departing from the spirit of the invention, including but not limited to all notch or lance type rivet islands. [0047] The webbing 42 further comprises a grab portion 54. The grab portion 54 is adapted for user manipulation. Typically, the grab portion 54 may include a finger hole 55 or the like. More recently, tabs have included fully closed grab portions 54 onto which information or the like can be etched, stamped, or incised. The enclosed grab portion 54 may have a recessed panel or finger well 58 formed therein. Such a finger well 58 is illustrate in FIGS. 2-4, showing an indicium 60 in the form of an aperture 64 extending from an upper surface of the tab 26 to a lower surface of the tab 26.

[0048] An example of a tab progression manufacturing method is illustrated in FIG 5. The tab-forming progression includes the steps of: (1) first providing an elongated strip of metal sheet 61 having a thickness along a central plane; (2) piercing the metal strip to form the void region 48, the indicium 60, a rivet hole 62, a relief notch 66, and tab retainers 70; (3) lancing the metal strip to form a lance cut-out 74, roughly in the shape of the finished tab 26; (4) bending the metal about the void region downwardly towards the lower surface of the tab 26; (5) forming the rivet island 46 and V-shaped coin 78 between the area that will be the nose 30 of the tab 26 and the rivet hole 62; (6) forming the finger well 58 within bounds of the lance cut-out 74 and about the indicium 60; and (7) rolling or bending the lance cut-out 74 to form a rolled edge which substantially defines a perimeter of the tab 26. It should be noted that the indicium 60 may be pierced prior to or subsequent to the forming of the finger well 58.

[0049] In the case where the indicium 60 is pierced subsequent to the forming of the finger well 58, as shown in FIG. 6, the indicium 60 would be pierced within the area or a boundary of the finger well 58. It is believed that forming the indicium 60 subsequent to forming the finger well achieves a better defined aperture with less distortion of metal, therefore an aesthetically more pleasing indicium 60.

[0050] At some point within the progression, subsequent to piercing, depending on when the piercing takes place, the indicium 60 is reworked or cold worked using a stamping, coining, compressing or other cold work process to produce a structure as described hereinafter.

[0051] A schematic forming of the indicium 60 is illustrated in FIG. 7. A cross-section schematic of the pierced grab portion 54 is illustrated in FIG. 8. Prior to reworking, the indicium 60 is generally defined by a circumferential wall 80 comprising a roll over depth D_R adjacent the upper surface of the sheet 61, a burnish depth D_B of sheared material 84 below the roll over depth D_R of a recessed portion of the sheet 82, a fracture depth D_F of fractured material 86 below the burnish depth D_B, and a burr height ¾ below the fracture depth 86. The burr height 88 comprises a burr 88 formed during the metal piercing. This structure is formed in accordance using typical metal forming practices that are well-known in the art of tab forming and metal working.

[0052] Schematic drawings of a reworking process are illustrated in FIGS. 9 and 10; a schematic of a reworked grab portion 54 is illustrated in FIG. 1 1. Subsequent to reworking, the aperture of the indicium 60 is at least partially defined by a reworked portion of the metallic sheet 61. The circumferential wall 80 comprises a reworked burr portion 90 including a first segment 92 of the burr height H_B. A second segment 94 of the reworked portion of the burr 90 is located radially outwardly from the first segment 92 relative to an imaginary central vertical axis of the indicium 60 perpendicular to the tab 26. Therefore, a radially outermost portion of the reworked portion of the metallic material in the sheet 61 , such as a portion of the reworked burr, is located radially outwardly of the circumferential wall 80, relative to the imaginary axis. The reworked portion of the burr 90 is flattened, compressed, and/or coined, such that the second segment 94 may be pressed or flattened against, and preferably engaging, the lower surface of the grab portion 54. Thus, the reworked burr 90 is located at least partially about the aperture of the indicium 60, adjacent the lower surface of the grab portion 54. It is contemplated that reworking the burr may cause portions of the burr height to be eliminated by flaking or a metal failure mechanism caused by the cold working of the metallic material. Though unlikely due to the physical properties of the metallic material, this would cause portions of the reworked to only partially orbit the aperture and void regions could occur along the lower, outer perimeter of the aperture.

[0053] Referring to FIG. 7, the indicium 60 is pierced by the combination of a first tool 100 and a second tool 200. The first tool 100 has a piercing surface 104, preferably having a shape adapted to form the desired indicium 60, in axial alignment with the metal sheet 100. The piercing tool 100 is preferably polished wherein a shape edge 108 defines a perimeter of the piercing surface 104 defining a piercing shape. A second tool or die 200 is in operable alignment with the piercing tool 100, such that relative movement between the first and second tools 100,200 pierces the metal sheet, producing the indicium 60 in the sheet 61 in the form of an aperture. The second tool 200 has an opening 204 which is complimentary in shape to the perimeter of the piercing tool 100.

[0054] The tools 100,200 are gapped or spaced horizontally to produce the desired characteristics in the sheet 61. Namely, the tools 100,200 are gapped to produce the circumferential wall 80 which substantially defines the shape of the indicium 60 as described above. As the tools 100,200 become worn the burr height 88 may become greater.

[0055] Subsequent to the piercing operation and either before or after formation of the finger well 58, the burr height H_B is compressed, coined, and/or flattened. In this operation, illustrated in FIGS. 9 and 10, a third tool 300 and a fourth tool 400 are placed in operable alignment, and the sheet 61 with the indicium 60 pierced therein passes between the tools 300,400 such that the indicium 60 is located between the tools 300,400. Relative movement between the tools 300,400 sandwiches the sheet 61 and the indicium 60 between the tools 300,400 so that the burr 88 is flattened, compressed, or coined.

[0056] The fourth tool 400 has a retaining surface 404 adapted, as in sized and shaped, to fit within the indicium 61. Accordingly, the retaining surface 404 has a similar shaped to the piercing surface 104 of the first tool 100. The retaining surface 404 has an edge 408 defining a perimeter of the retaining surface 404. The edge 408 has a rounded corner having a radius of curvature greater than the radius of curvature of the edge 108 of the piercing surface 104. The retaining surface 404 extends outwardly/upwardly from a portion of the tool 400, and the primary purpose of the retaining surface 404 is to retain the shape of the indicium 60 during the reworking operation and to prevent excess metal from entering the aperture subsequent to the reworking operation.

[0057] The third tool 300 has a generally flat or planar working surface 304, and/or the third tool has an opening 308 having a complimentary shape to that of the retaining surface 404, such that the opening is adapted, as in sized and shaped, to receive the retaining surface 404 therein. The working surface 304 engages the upper surface of the sheet 61 during the reworking operation.

[0058] In operation, the indicium 60 is brought into alignment between the third and fourth tools 300,400. Relative movement between the tools 300,400 causes the retaining surface 404 to enter the aperture of the indicium 60 and possibly, but not necessarily, into the opening 308 in the third tool 300. Further relative movement between the tools 300,400 causes the burr height H_B to be reduced by compression of the burr 88 between the tools 300,400 against the sheet 61. The retaining surface 404 preferably enters the aperture upon engagement of the engaging surface 304 of the third tool 300 with the upper surface of the sheet 61, which forces the aperture downwardly around the retaining surface 404 until the burr height engages a circumferential portion 412, generally an annular concave curved portion joining the retaining surface 404 with a planar portion 416 of the fourth tool 400 about the lowermost portion of the retaining surface 404.

[0059] The terms "first," "second," "upper," "lower," "top," "bottom," etc. are used for illustrative purposes relative to other elements only and are not intended to limit the embodiments in any way. The term "plurality" as used herein is intended to indicate any number greater than one, either disjunctively or conjunctively as necessary, up to an infinite number. The terms "joined," "attached," and "connected" as used herein are intended to put or bring two elements together so as to form a unit, and any number of elements, devices, fasteners, etc. may be provided between the joined or connected elements unless otherwise specified by the use of the term "directly" and/or supported by the drawings. The term "flattened" is intended to encompass or describe any portion of the reworked portion of the burr height in a location so described. The term "flattened" is not intended to limit the description to a particular surface of the burr height, unless so described. For example, a "flattened" portion of the reworked burr height may engage the lower surface of the grab portion; alternatively, or additionally, a "flattened" portion of the reworked burr height may be separated from the lower surface of the grab portion by a thickness of the metallic material in the burr. Thus, it follows that in the claims, a "flattened" portion of the metallic material can be located anywhere, unless limited further by the language of the claims.

[0060] While specific embodiments have been illustrated and described, numerous modifications come to mind without significantly departing from

[0061] While the specific embodiments have been illustrated and described, numerous modifications come to mind without significantly departing from the spirit of the invention, and the scope of protection is only limited by the scope of the accompanying Claims.

Claims

CLAIMS What is claimed is:

1. A non-detachable pull tab (26) for a beverage container comprising:

a nose end (30);

a lift end opposite the nose end (30); and

a central webbing (42) of a metallic material between the nose (30) and lift ends (32), the central webbing (42) comprising:

a hinge region (44);

a rivet island (46) surrounding a rivet hole, the rivet island (46) being at least partially surrounded by a first void region; and

a grab portion (54) between the first void region and the lift end (32), the grab portion (54) having an upper surface and a lower surface and an aperture

therethrough, the aperture defined by a circumferential wall (80) of the grab portion (54) extending from the upper surface to the lower surface and comprising a first segment (92) of a reworked portion of a burr (90).

2. The non-detachable pull tab (26) of Claim 1 wherein a second segment (94) of the reworked portion of the burr (90) is located radially outwardly from the first segment (92) of the reworked portion of the burr (90).

3. The non-detachable tab (26) of Claim 1 wherein the circumferential wall (80) comprises a birnished section (84) located adjacent the upper surface of the grab portion (54).

4. The non-detachable tab (26) of Claim 3 wherein the circumferential wall (80) comprises a fractured section (86) located adjacent the burnished section (84).

5. The non-detachable tab (26) of Claim 1 wherein the aperture is in a form of an indicium (60) to convey information to a user.

6. The non-detachable tab (26) of Claim 1 wherein the reworked portion of the burr (90) is flattened relative to the lower surface of the grab portion (54).

7. The non-detachable of Claim 1 wherein the reworked portion of the burr (90) is flattened against the lower surface of the grab portion (54).

8. The non-detachable tab (26) of Claim 1 wherein the circumferential wall (80) of the grab portion (54) comprises a pierced portion of the grab portion (54) comprising:

a first portion of a burnish depth (D_B); and

a second portion of a fracture depth;

wherein the reworked portion of the burr (90) comprises a flattened portion of the burr (90) engaging the lower surface of the grab portion (54).

9. The non-detachable tab (26) of Claim 1 wherein the reworked portion of the burr (90) is located adjacent the lower surface of the grab portion (54).

10. A non-detachable pull tab (26) for a beverage container comprising:

a nose end (30);

a lift end (32) opposite the nose end (30); and

a hinge region (44);

a grab portion (54) comprising an indicium (60), the indicium (60) comprising an aperture at least partially defined by a wall of a pierced segment of the metallic material extending from the upper surface to the lower surface of the grab portion (54) and comprising a fractured portion (86) of the metallic material, and a reworked portion of a burr (90) located at least partially about the aperture, the reworked portion comprising a flattened segment.

11. The non-detachable tab (26) of Claim 10 wherein the reworked portion of the burr (90) is located adjacent the lower surface of the grab portion (54) and is flattened

thereagainst.

12. A non-detachable pull tab (26) for a beverage container comprising:

a nose end (30);

a lift end (32) opposite the nose end (30); and

a central webbing (42) of a metallic material between the nose and lift end (32), the central webbing (42) comprising: a hinge region (44);

a grab portion (54) between the first void region and the lift end (32), the grab portion (54) having an upper surface and a lower surface and an indicium (60) in the form of an aperture having a perimeter at least partially defined by a reworked portion of the metallic material.

13. The non-detachable tab (26) of Claim 12 wherein the reworked portion of the metallic material comprises a flattened segment engaging the lower surface of the grab portion (54).

14. The non-detachable tab (26) of Claim 13 further comprising a circumferential wall (80) defining a portion of the aperture between the upper surface and the lower surface of the grab portion (54) wherein the circumferential wall (80) comprises:

a first portion of a burnish depth (D_B);

a second portion of a fracture depth (D_F) ; and

a portion of the burr (90).

15. The non-detachable tab (26) of Claim 14 wherein the central webbing (42) further comprises:

a void region partially surrounding the rivet island (46).

16. The non-detachable tab (26) of Claim 15 wherein the grab portion (54) further comprises:

a recessed panel between the lift end (32) and the void region wherein the indicium (60) is located within the recessed panel.

17. The non-detachable tab (26) of Claim 16 wherein a radially outermost portion of the reworked portion of the burr (90) is located radially outwardly of the circumferential wall (80) relative to a central vertical axis of the grab portion (54).

18. An apparatus for forming a non-detachable tab (26) comprising:

a first tool (100) having a piercing surface in a shape to form an indicium (60); a second tool (200) in operable alignment with the first tool (100) having an opening complimentary to the piercing shape of the first tool (100) for receiving the piercing surface therein;

a third tool (300) having a shape retaining surface similar to the piercing surface; and a fourth tool (400) in operable alignment with the third tool (300).

19. The apparatus of Claim 18 wherein the piercing surface of the first tool (100) has a sharp edge defining a perimeter of the piercing surface.

20. The apparatus of Claim 19 wherein the retaining surface has an edge defining a perimeter of an upper surface of the third tool (300) having a radius of curvature greater than a radius of curvature of the sharp edge of the piercing surface.

21. The apparatus of Claim 20 wherein the fourth tool (400) has an opening located radially inwardly of an engagement surface.

22. The apparatus of Claim 21 wherein the engagement surface relatively flat.

23. A method for forming a non-detachable tab (26) comprising the steps of:

providing a sheet of a metallic material;

a first tool (100) having a piercing surface in a shape to form an indicium (60); a second tool (200) in operable alignment with the first tool (100) having an opening complimentary to the piercing shape of the first tool (100);

passing the sheet of metallic material between the first and second tools (200);

forming an indicium (60) on the sheet of metallic material by piercing the sheet of metallic material through relative movement between the first and second tools (100, 200); and

providing a third tool (300);

providing a fourth tool (400) in operable alignment with the third tool (300);

passing the indicium (60) between the third and fourth tools (300,400); and reworking a burr (88) created in the forming an indicium (60) step by providing relative movement between the third and fourth tools (300,400).

24. The method of Claim 23 wherein the third tool (300) has a retaining surface having similar shape to the piercing surface on the first tool (100).

25. The method of Claim 24 further comprising the step of:

inserting the retaining surface within the indicium (60) pierced in the sheet of metallic material.

26. The method of Claim 24 further comprising the step of:

inserting the retaining surface within the indicium (60) pierced in the sheet of metallic material and compressing the burr (88) against an annular concave curved portion joining the retaining surface with a portion of the third tool (300).