ES2405267T3 - Easy opening can end with high pressure ventilation - Google Patents

Abstract

A full opening convenience closure (50) that is adapted for sealing a can end, comprising an end panel (52), a peripheral notch (72) in the end panel (52), defining the peripheral notch (72) fixed (74) and removable portions (76) of the end panel (52), a tongue (60) having a pointed part (63) to exert a downward force on the end panel (52) in an area next to the peripheral notch (72), a rivet formation (66) for fixing the tongue (60) to the end panel (52), the closure (50) further comprising a notch of the flexion line (80, 280) defined in the end panel (52) and located adjacent to the rivet formation (66), said notch of the flexion line (80, 280) having a first portion (94) that is located on a first side of the rivet formation ( 66) and a second portion (96) that is located on a second side, opposite the formation of the rivet (66), and a notch A mustache (78,278) defined in the end panel (52) that includes a central portion (84) that is positioned radially inwardly in the end panel (52) in relation to the formation of the rivet (66) and is curved on the formation of the rivet (66) such that a concave side of the central portion (84) faces the formation of the rivet (66) and includes first and second end portions (86, 88) that are preferably symmetrical with respect to the other around a diametral axis of symmetry (82) that extends through the center (90) of the rivet formation (66); characterized in that at least two notches of the break line (98, 100, 298,300) are defined in the end panel (52) to provide a previously weakened tearing path between the mustache notch (78, 278) and the notch of the flexion line (80, 280).

Description

Easy opening can end with high pressure ventilation

Technical field

The present invention relates generally to the field of convenience closures for can ends of the full opening type. More specifically, the present invention relates to convenience closures for can ends of the full opening type that are suitable for use in pressurized food can applications. Additional aspects of the invention relate to a method and a set of tools for manufacturing such a convenience closure.

Prior art

One form of self-opening can that is widely used is the so-called full opening can, in which a peripheral notch, generally of circular configuration, is formed in the end panel at, or adjacent to the periphery thereof to allow Its complete elimination.

Full opening type cans must be distinguished from those automatic opening cans that have a comparatively small removable section, which, when opened, provides a comparatively small hole for dispensing the product. This last type of can end is only suitable for soda, beer or other liquid containers. Full opening type cans, on the other hand, are suitable for packaging solid products, such as sweets, nuts, meats, or ground coffee.

A fully conventional opening type can of the type described in U.S. Pat. 5,232,114 to Zysset is shown in Figure 1. The can end 10 conventionally includes an end panel 12 and a peripheral flange with a curled edge 14 which are adapted to be folded together with an end flange of a body of the can. On or adjacent to the periphery of the end panel 12 there is a peripheral notch 16 that is indented in the end panel 12 and defines a fixed can end portion 18 and a removable portion or panel 20. A grip tab 22 is mounted at the end panel 12 by means of a rivet formation 24.

The grip tab 22 is positioned close enough to the peripheral notch 16 so that when its inner end is tilted upwardly to make its outer end move downward and exert a downward force on the end panel 12 on or near the peripheral notch 16, a portion of the end panel 12 is bent downwards to initiate the rupture of the peripheral notch 16. Thereafter, a pull up and back on the grip tab 22 by the user induces tearing the metal in the peripheral notch 16 on both sides of the initial rupture zone to complete the detachment of the can from the removable portion or panel 20 of the end panel 12.

It is also known in the prior art the use of a ventilation notch behind the formation of the rivet 24 towards the center of the end panel 12 in order to relieve the internal or vacuum pressure that exists within the container, and thereby avoid implosion or explosion when the container is opened by pivoting the grip tab 22 on the formation of the rivet 24. The most commonly used form for the ventilation notch is curved like a man's mustache, so these results are generally known as "mustache notch".

For the aforementioned purposes and to promote flexibility and to provide an articulation point for the tongue 22 when raised, a mustache notch 34 can be formed on the end panel 12, as illustrated in Figure 1. The notch Mustache 34 typically has an inner portion 36 that is defined in a boss 26 of the rivet formation 24 having an outer edge 27, and at least an outer portion 38 that is defined on the outer surface of the end panel 12. The protuberance 26 includes a first oval-shaped operating bubble 40, which is elongated along an axis that is perpendicular to a rope of an end panel radius 12. The protuberance 26 further includes a second operating bubble 30, which It is defined centrally with respect to the first operating bubble 40.

The inner part 36 of the mustache notch 34 may be curved around the radial inner periphery of the second operating bubble 30. The outer parts 38 of the mustache notch 34 would normally be shaped to appear outward from the respective inner portions 36 , and which typically end at their outer outer ends to be substantially parallel or slightly curved away from the peripheral notch 16.

Although conventional mustache notches, such as the one described above, are generally effective in preventing violent explosions or implosions during the opening of containers that are moderately under pressure or under pressure, which tend to be ineffective in preventing of explosions during the opening of highly pressurized containers. A highly pressurized container for the purposes of this document is a container that is under pressure at least 25 pounds per square inch under ambient pressure conditions.

Document CH 513 748 A (American Can Co) discloses a convenience closure having the characteristics of the precautionary part of claim 1.

There is a need for an improved easy opening can end that can be used with highly pressurized containers and is able to effectively reduce the likelihood of a violent explosion or implosion that occurs when said container is opened at high pressure.

Accordingly, it is an object of the invention to provide an improved easy-opening can end that can be used with highly pressurized vessels and is capable of effectively reducing the likelihood of a violent explosion or implosion that occurs when said vessel is opened under high pressure. .

Description of the invention

In order to achieve the foregoing and other objects of the invention, a complete opening convenience closure that is adapted for sealing an end of a can according to a first aspect of the invention comprises an end panel, a notch peripheral in the end panel, the peripheral notch defining fixed and removable parts of the end panel, a tongue having a pointed part to exert a downward force on the end panel in an area close to the peripheral notch, a rivet formation to fasten the tongue to the end panel, the closure further comprising a notch of the bending line defined in the end panel and located adjacent to the rivet formation, which has a first portion that is located on a first side of the rivet formation and a second portion that is located on a second side, opposite the rivet formation, and a mustache notch defined in the outer panel oar that includes a central part that is radially inwardly positioned in the end panel with respect to the rivet formation and bends over the rivet formation such that a concave side of the central part faces the formation of the rivet. rivet and includes first and second end portions that are preferably symmetrical with respect to each other around a diametral axis of symmetry extending through the center of the rivet formation; which includes a central portion that is radially inwardly positioned at the end of the panel in relation to the formation and the rivet is curved over the rivet formation such that a concave side of the central portion faces the rivet formation and includes first and second end portions that are preferably symmetrical with respect to each other around a diametral axis of symmetry that extends through the center of the rivet formation, characterized in that at least two notches of the break line are defined on the end panel to provide a previously weakened tear path between the mustache notch and the notch of the flex line.

In a second aspect of the invention, there is provided a method of performing the above convenience closure, comprising: providing an end panel;

form a mustache notch in the end panel;

form a notch of the bending line on the end panel adjacent to the mustache notch;

characterized in that the procedure further comprises:

form at least two notches of break line between the mustache notch and the notch of the flex line.

In a third aspect of the invention, a set of tools is provided for the formation of a closing end panel, convenience of full opening above, comprising:

a first forming tool to form an upper surface of an end panel for an easily open can end, said first forming tool comprising:

a first surface of the tool that is constructed and arranged to form a mustache notch in the end panel;

a second surface of the tool that is constructed and arranged to form a notch of the bending line in the end panel that is in a predetermined relationship with respect to the mustache notch;

the set of tools also comprising:

a second training tool that is built and ready to work together with the first training tool, and

a press set for driving at least one of the first and second training tools;

characterized in that the first forming tool further comprises third and fourth surfaces of the tool for forming the first and second breaking line notches.

These and several other advantages and novelty features that characterize the invention are pointed out with particularity in the appended claims and which form part thereof. However, for a better understanding of the invention, its advantages, and the objects obtained by its use, reference should be made to the drawings that form an additional part thereof, and to the accompanying descriptive subject, which is illustrated and describes a preferred embodiment of the invention.

Brief description of the drawings

Figure 1 is a schematic view of a previously known easy opening can end configuration;

Figure 2 is a perspective view of an easy opening can end that is constructed in accordance with a preferred embodiment of the invention;

Figure 3 is a fragmentary cross-sectional view of the easy-opening can end shown in Figure 2;

Figure 4 is a fragmentary cross-sectional view of a press assembly that is preferably used in accordance with a preferred embodiment of the invention;

Figure 5 is a schematic representation of an opening notch pattern and a forming tool according to a preferred embodiment of the invention;

Figure 6 is a schematic representation of an opening notch pattern and a forming tool according to a modified embodiment;

Figure 7 is a schematic representation of the opening notch pattern shown in Figure 5;

Figure 8 indicates that the seven forming operations in a preferred method of forming an easy-opening can end according to a preferred embodiment of the invention;

Fig. 9 is a schematic representation of an improved opening notch pattern and a forming tool according to the preferred embodiment of the invention; Y

Figure 10 is a schematic representation of the opening notch pattern shown in Figure 9.

Embodiment (s) of the invention

Referring now to the drawings, in which reference numbers designate the corresponding structure in all views, and with particular reference to Figures 2 and 3, a full opening convenience closure

or an easy opening can end 50 that is constructed in accordance with a preferred embodiment of the invention includes an end panel 52 having pictorial opening instructions 54 embossed thereon. As is conventional, a peripheral notch 72 has been formed in the end panel 52 and defines a fixed portion 74 of the end panel 52 and a removable portion 76 of the end panel 52. A finger hole 56 is defined on a surface upper end panel 52.

The full opening convenience closure 50 further includes a circumferentially extending end curl or sewing panel 58 that is constructed and arranged to be fixed to a container by a double stitching process. It also includes a tongue 60 having a main body portion 62 that includes a tip portion 63 that is constructed and disposed to exert a downward force on the end panel 52 in an area that is close to the peripheral notch 72 when a lifting ring 64 of the tongue 60 is lifted by a consumer. A rivet formation 66 secures the tongue 60 to the end panel 52. The convenience closure 50 further preferably includes a double fold 68 which is defined in the end panel 52 adjacent to the peripheral notch 72 in order to provide protection against cuts. for a consumer

According to a particularly advantageous feature of the invention, a plurality of the opening notches 70 is preferably defined in the end panel 52 in an area that is generally close to the location of the rivet formation 66. The opening notches 70 they include a mustache notch 78, a notch of the bending line 80 and a pair of notches of break lines 98, 100, which is best seen in the figure

7. Although in the preferred embodiment, the end panel 52 has all these notches defined therein, it should be understood that in alternative embodiments not covered by the claims the mustache notch 78 could be provided with a notch of the flexure line, with or Without a break in the break line.

Figure 7 provides a more detailed view of the opening notches 70 in the preferred embodiment. As Figure 7 shows, the mustache notch 78 preferably includes a central portion 84 that is positioned radially inwardly at the end panel 52 relative to the formation of the rivet 66 and bends over the formation of the rivet 66 in such a manner. that a concave side of the central portion 84 faces the formation of the rivet 66. The curvature of the central portion 84 is preferably a constant radius of curvature.

The mustache notch 78 preferably further includes first and second end portions 86, 88 which are preferably symmetrical with respect to each other about a diametral axis of symmetry 82 extending through the center 90 of the rivet formation 66. Each of the first and second end portions 86, 88 preferably includes a convex side of the curvature that faces the closest parts of the peripheral notch 72.

Each of the first and second end portions 86, 88 preferably have a constant radius of curvature R1 that preferably extends along an arc section that is at least about 150 °. The constant radius of curvature R1 is preferably substantially within a range of about 1.78 mm (0.07 inches) to about 5.1 mm (0.2 inches). The distal ends of the first and second end portions 86, 88 in the preferred embodiment point outside the nearest part of the peripheral notch 72, and a tangent line extending through the distal ends (ie, tangential to the distal ends) would preferably be substantially perpendicular to the tangent of the peripheral notch 72 in a position where the first line of the tangent would cross the peripheral notch 72.

Preferably, a transition location 92 between the central portion 84 and the first end portion 86 is at a transition angle α from the diametral axis of symmetry 82 which is preferably substantially within a range of about 45 ° to about 60 ° . More preferably, this angle is substantially within a range of about 50 ° to about 55 °.

The notch of the flexure line 80 preferably has a first portion 94 that is on a first side of the rivet formation 66 and a second portion 96 that is on a second side, opposite the formation of the rivet 66. The first and second portions 94, 96 of the notch of the flexion line 80 are aligned and preferably symmetrical with respect to each other and are both linear. The notch of the flexure line 80 and its components 94, 96 are preferably substantially perpendicular to the diametral axis of symmetry 82.

The notch of the bending line 80 preferably has a residual thickness (i.e., a thickness that remains on the end panel 52 at the location of the notch in line 80) that is substantially the same as a residual thickness of the notch. mustache 78. The notch of the flexure line 80 preferably also has a residual thickness that is within a range of about 25% to about 40% of a thickness of the end panel 52. More preferably, the notch of The flexure line 80 has a residual thickness that is substantially within a range of about 30% to about 35% of the thickness of the end panel 52.

The mustache notch 78 has a residual thickness that is preferably substantially within a range of about 25% to about 40% of the thickness of the end panel 52. More preferably, the mustache notch 78 has a residual thickness that is substantially within a range of about 30% to about 35% of the thickness of the end panel 52. The mustache notch 78 preferably has a residual thickness that is not greater than about 0.1143 mm (0.0045 inches) and more preferably not greater than about 0.0889 mm (0.0035 inches).

As Figure 7 shows, the parts of the mustache notch 78 that most closely approximate the notch of the flex line 80 have a convex side of the curvature that gives the notch of the flex line 80.

As seen in Figure 7, in the preferred embodiment of the invention, a pair of the break line notches 98, 100 are defined in the end panel 52 in order to provide a previously weakened tear path between the notch. of mustache 78 and the notch of the flexion line 80 which is used by the convenience closure 50 during the preliminary stages of the opening. The break line notches 98, 100 are located between the mustache notch 78 and the notch of the flex line 80. Each of the break line notches 98, 100 is preferably substantially perpendicular to the notch of the line of flexion 80 and is aligned with locations in the respective first and second end portions 86, 88 of the mustache notch 78 that most closely approximates the notch of the flexure line 80.

The notches of the break line 98, 100 are preferably substantially perpendicular with respect to the tangent lines that pass through the locations in the respective first and second end portions 86, 88 of the mustache notch 78 that are closer to the notch of the bending line 80. The notches of the break line 98, 100 preferably have a residual thickness that is greater than a residual thickness of the notch of the flex line 80 and that is greater than a residual thickness of the mustache notch 78. The residual thickness of the break line notches 98, 100 is preferably substantially within a range of about 30% to about 95% of the thickness of the end panel 52, with a more preferred range of about 50% to about 80% of the thickness of the end panel 52.

When the convenience closure 50 is used in conjunction with a content can body for packaging under high pressure (i.e., more than 20 psi), which can be opened by a consumer by holding the lifting tab 60 and pulling the lifting ring 64 up.

As the grip tab 60 pivots around the formation of the rivet 66, the tip portion 63 is

will move down and exert a force down on the end panel 52 at or near the peripheral notch 72. Before the end panel 52 bends down enough to initiate the rupture of the peripheral notch 74, however , sufficient tension is formed in the end panel 52 in the area near the central portion 84 of the mustache notch 78 to cause a breakage of the end panel in the central portion 84.

The pressurized gas inside the vessel will be allowed to vent without causing damage through breakage in the central portion 84 of the mustache notch 78 without affecting the integrity of the peripheral notch 72 or accelerating the opening process. The flow of pressurized gas will tend to be directed without causing damage at an oblique angle below the consumer's fingers through the top of the end panel 52 so as not to present a risk to the consumer.

The presence of the notch of the flexure line 80 reduces the amount of force that will have to be exerted by the consumer to cause the initial rupture of the central portion 84 of the mustache notch 78.

After the convenience closure 50 has been vented, the consumer will continue to pull the lifting ring 64 upward, which causes the tear or breakage in the central portion 84 of the mustache notch 78 to be enlarged. The tearing will progressively advance at the first and second end portions 86, 88 of the mustache notch 78. At the location of the first and second end portions 86, 88 that is closer to the notch of the flex line 80, the line The cut will leave the mustache notch 78 and advance directly to the respective first and second parts 94, 96 of the notch of the bending line 80 along the path of the break line notches 98, 100. This will occur even in embodiments in which the notches of the break line 98, 100 are not present.

The tear will move laterally outward along the respective first and second parts 94, 96 of the notch of the flexion line 80. While this occurs, sufficient downward force will be exerted by the tip portion 63 of the tongue tongue. grip the peripheral notch 74 at break. The consumer can now pull the lifting ring 64 again to cause the peripheral notch 74 to tear, thereby removing the removable portion 76 of the end panel 52 of the fixed part 74.

Referring now to Figure 4, the set of tools for forming the closure 50 in accordance with the convenience of the preferred embodiment includes a third set of operating press 101 including an upper portion 102 and a lower portion 104 that are mounted to move with respect to the other. The tool set further preferably includes a first forming tool 106 to form an upper surface of the end panel 52 of the convenience closure 50.

Looking now at Figure 5, it will be seen that the first forming tool 106 preferably includes a first surface of the tool 108 that is constructed and arranged to form the mustache notch 78 and a second surface of the tool 110 that is constructed and arranged for forming the notch of the bending line 80. The second surface of the tool 110 includes a first portion 112 to form the first portion 94 of the notch of the bending line 80 and a second portion 114 to form the second portion 96 of the notch of the bending line 80. The first forming tool 106 also preferably includes a third surface of the tool 116 to form the first notch of the break line 98 and a fourth surface of the tool 118 to form the second notch of the break line 100. Both the first surface of the tool 108 and the second surface of the tool 110 are formed s as protrusions extending outward from the substantially flat horizontal base surface of the first forming tool 106.

Figure 6 depicts a first forming tool 120 according to a modified embodiment. The first forming tool 120 is identical in all respects to the first forming tool 106 described above, except that it lacks the third and fourth surfaces of the tool 116, 118 for the formation of the first and second groove of the break line 98, 100. The first forming tool 120 is used for the manufacture of a convenience closure according to a modified embodiment in which the notches of the break line 98, 100 are not present.

A method of manufacturing said convenience closure 50 in accordance with the preferred embodiment of the invention would include a step of providing a blank of the end panel and providing the tools discussed above in relation to Figures 4-5. The tooling is otherwise used in the conventional manner to form the convenience closure discussed in detail above.

The preferred method of making the convenience closure 50 uses a seven-process manufacturing process, as indicated in Figure 8.

The first forming operation is used to form the formation of the rivet bubble in the rough end panel.

The second training operation completes the formation of the rivet button and starts the formation of a lower security fold.

The third forming operation forms the notch lines that have been described in detail above and previously folds an upper security fold.

The fourth operation completes the folding of the lower safety cover.

The fifth operation involves stacking the tongue to the end panel and a final riveting operation.

The sixth operation includes a tongue detection function, as well as a stage for forming a pre-protuberance of the upper fold.

The seventh and final operation involves a stage of completing the folding of the upper fold in a position where cut protection will be offered.

Referring now to Figures 9 and 10, an easy-opening can end that is constructed according to a second, preferred embodiment of the invention is identical to that described above with respect to the first embodiment of the invention, except that is described otherwise in this document.

As Figure 10 shows, a plurality of opening notches 270 are preferably defined on the end panel of the end of the can in an area that is generally close to the location of the rivet formation 224, shown in Figure 9. The opening notches 270 preferably include a mustache notch 278, a notch of the bending line 280 and a pair of notches of break lines 298, 300, which is best shown in Figure 10. Although in the preferred embodiment , the end panel has all these notches defined therein, it should be understood that in alternative embodiments not covered by the claims the mustache notch 278 could be provided with a notch of the flexion line 280, with or without a notch of the break line

As Figure 10 shows, the mustache notch 278 preferably includes a central portion 284 that is radially inwardly positioned in the end panel with respect to the formation of the rivet 224 and bends over the formation of the rivet 224 in such a manner. that a concave side of the central portion 284 faces the formation of the rivet 224. The curvature of the central portion 284 is preferably a constant radius of curvature.

The mustache notch 278 further preferably includes first and second end portions 286, 288 which are preferably symmetrical with respect to each other about a diametral axis of symmetry 282 extending through the center of the rivet formation 224. Each one of the first and second end portions 286, 288 preferably includes a convex side of the curvature that faces the closest parts of the peripheral notch 272. Each of the first and second end portions 286, 288 preferably have a constant radius of curvature R1 that preferably extends along an arc section that is at least about 150 °. The constant radius of curvature R1 is preferably substantially within a range of about 1.78 mm (0.07 inches) to about 5.1 mm (0.2 inches).

The distal ends of the first and second end portions 286, 288 in the preferred embodiment point to the nearest part of the peripheral notch 272, and a tangent line extending through the distal ends (i.e., tangential to the distal ends) would preferably be substantially perpendicular to the tangent of the peripheral notch 272 in a position where the first line of the tangent would cross the peripheral notch 272.

Preferably, a transition location 292 between the central part 284 and the first end portion 286 is located at a transition angle α from the diametric axis of symmetry 282 which is preferably substantially within a range of from about 45 ° to about 60 ° . More preferably, this angle is substantially within a range of about 50 ° to about 55 °.

The notch of the flexure line 280 preferably has a first portion 294 that is located on a first side of the rivet formation 224 and a second portion 296 that is located on a second side, opposite the formation of the rivet 224. The first portion 294 in this embodiment of the invention preferably includes a substantially linear portion 304 that is close to the formation of the rivet 224 and a second part, curved 306 at one end of the first portion 294 that is distal to the formation of the rivet 224 .

Similarly, the second portion 294 in this embodiment of the invention preferably includes a substantially linear portion 308 that is close to the formation of the rivet 224 and a second, curved portion 310 at one end of the second portion 296 that is distal of the formation of the rivet 224.

One of the purposes of the curved portions 306, 310 is to deter that the possible tear occurs near the outer distal ends of the first and second notch portions of the flexure line 294, 296 during and after the opening of the end of Easy opening by a consumer.

The first and second portions 294, 296 of the notch of the flex line 280 are aligned and preferably

symmetrical with respect to the other.

The linear portions 304, 308 of the notch of the flexure line 280 and its components 294, 296 are preferably substantially perpendicular with respect to the diametral axis of symmetry 282.

The notch of the bending line 280 preferably has a residual thickness (i.e., a thickness that remains in the end panel at the location of the notch in line 280) that is substantially the same as a residual thickness of the notch of mustache 278. The notch of the flexure line 280 also preferably has a residual thickness that is within a range of about 25% to about 40% of an end panel thickness. More preferably, the notch of the flexure line 280 has a residual thickness that is substantially within a range of about 30% to about 35% of the thickness of the end panel.

The mustache notch 278 has a residual thickness that is preferably substantially within a range of about 25% to about 40% of the thickness of the end panel. More preferably, the mustache notch 278 has a residual thickness that is substantially within a range of about 30% to about 35% of the thickness of the end panel. The mustache notch 278 preferably has a residual thickness that is not greater than about 0.1143 mm (0.0045 inches), and more preferably not greater than about 0.0889 mm (0.0035 inches).

As Figure 10 shows, the parts of the mustache notch 278 that most closely approximate the notch of the flex line 280 have a convex side of the curvature that faces the notch of the flex line 280.

In this preferred embodiment of the invention, a pair of the notches of the break line 298, 300 are defined in the end panel in order to provide a previously weakened tear path between the mustache notch 278 and the notch of the flex line 280 which is used for the closing of convenience during the preliminary stages of the opening. The notches of the break line 298, 300 are located between the mustache notch 278 and the notch of the flex line 280. Each of the break line notches 298, 300 are preferably substantially perpendicular to the notch of the line. of bending 280 and are aligned with the locations in the respective first and second end portions 286, 288 of the mustache notch 278 that most closely approximates the notch of the bending line 280.

The notches of the break line 298 300 are preferably substantially perpendicular with respect to the tangent lines that pass through the locations in the respective first and second end portions 286, 288 of the mustache notch 278 that most closely approximates the notch of flexion line 280.

The notches of the break line 298, 300 preferably have a residual thickness that is greater than a residual thickness of the notch of the flexure line 280 and that is greater than a residual thickness of the mustache notch 278. The residual thickness of The break line notches 298, 300 are preferably substantially within a range of about 30% to about 95% of the thickness of the end panel, with a more preferred range of about 50% to about 80% of the thickness of the end panel. .

The presence of the notch of the flexure line 280 reduces the amount of force that will have to be exerted by the consumer to cause the initial rupture of the central portion 284 of the mustache notch 278.

Looking now at Figure 9, it will be seen that the first forming tool 206 preferably includes a first surface of the tool 208 that is constructed and arranged to form the mustache notch 278 and a second surface of the tool 210 that is constructed and arranged for forming the notch of the flex line 280. The second surface of the tool 210 includes a first portion 212 to form the first linear portion 304 of the first portion 294 of the notch of the flex line 280 and a second portion 220 to form the curved portion 306 of the first portion 294 of the notch of the flexure line 280. A third portion 214 is further included to form the linear portion 308 of the second portion 296 of the notch of the flexure line 280 and a fourth portion 222 to form the curved portion 310 of the second portion 296 of the notch of the flexure line 280.

The first forming tool 206 also preferably includes a third surface of the tool 216 to form the first notch of the break line 298 and a fourth surface of the tool 218 to form the second notch of the break line 300. Both the first Tool surface 208 as the second tool surface 210 are formed as protrusions extending outwardly from the substantially flat horizontal base surface of the first forming tool 206.

It should be understood, however, that although numerous features and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and can be made changes of details, especially in matters of shape, size and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.

Claims (13)

1. A full opening convenience closure (50) that is adapted for sealing an end of a can, comprising an end panel (52), a peripheral notch (72) on the end panel (52), defining the peripheral notch (72) fixed (74) and removable portions (76) of the end panel (52), a tongue (60) having a pointed part (63) to exert a downward force on the end panel ( 52) in an area close to the peripheral notch (72), a rivet formation (66) for fixing the tongue (60) to the end panel (52), the closure (50) further comprising a notch of the bending line ( 80, 280) defined on the end panel

(52)

 and located adjacent to the rivet formation (66), said notch of the flexion line (80, 280) having a first portion (94) that is located on a first side of the rivet formation (66) and a second portion

(96)

 which is located on a second side, opposite the formation of the rivet (66), and a mustache notch (78, 278) defined in the end panel (52) that includes a central portion (84) that is radially positioned toward the interior in the end panel (52) in relation to the formation of the rivet (66) and is curved over the formation of the rivet (66) such that a concave side of the central portion (84) faces the formation of the rivet (66) and includes first and second end portions (86, 88) that are preferably symmetrical with respect to each other about a diametral axis of symmetry (82) extending through the center (90) of the rivet formation (66); characterized in that at least two notches of the break line (98, 100, 298, 300) are defined in the end panel (52) to provide a previously weakened tearing path between the mustache notch (78, 278) and the notch of the flexion line (80, 280).

2.

A convenience closure (50) as claimed in claim 1, wherein the notches of the break line (298, 300) have a residual thickness within the range of 30-95% of the thickness of the end panel (52) .

3.

A convenience closure (50) as claimed in any one of claim 1 or 2, wherein the notches of the break line (298, 300) have a residual thickness greater than the residual thickness of the notch of the flex line (280) and greater than the residual thickness of the mustache notch (278).

Four.

A convenience closure (50) as claimed in any preceding claim, wherein the notch of the flexion line (280) comprises a linear portion (304, 308) and a curved portion (306, 310).

5.

A convenience closure (50) as claimed in claim 4, wherein the curved portion (306, 310) of the notch of the flexure line (280) is curved toward the mustache notch (278).

6.

A convenience closure (50) as claimed in any preceding claim, wherein the end panel (52) has a symmetry diametral axis (282) that extends through the formation of the rivet (66), and in the notch of the flexion line (280) is symmetric with respect to the diametral axis of symmetry (282).

7.

A convenience closure (50) as claimed in any preceding claim, wherein the notch of the bending line (280) has a residual thickness within the range of 25-40% of the thickness of the end panel (52).

8.

A method of carrying out the convenience closure according to claim 1, the method comprising:

provide an end panel (52); form a mustache notch (278) in the end panel (52); forming a notch of the flexion line (280) in the end panel (52) adjacent to the mustache notch (278); characterized in that the procedure further comprises: form at least two notches of break line (298, 300) between the mustache notch (278) and the notch of the flex line (280).

9.

A method as claimed in claim 8, wherein the notch of the flexure line (280) is formed with a linear portion (304, 308) and a curved portion (306, 310).

10.

A method as claimed in any one of claim 8 or 9, further comprising forming a rivet formation (66) in the end panel (52), the notch of the flexion line being

(280) formed adjacent to the rivet formation (66). 11. A set of tools (101) for forming the end panel of a full opening convenience closure (50) according to claim 1, the set of tools comprising: a first forming tool (106, 206) for forming an upper surface of an end panel (52) for an easily open can end, said first forming tool (206) comprising: a first surface of the tool (208) that is constructed and arranged to form a mustache notch (278) in the end panel (52); a second surface of the tool (210) that is constructed and arranged to form a notch of the bending line (280) in the end panel (52) that is in a predetermined relationship 5 with respect to the mustache notch (278) ; the set of tools that also includes: a second training tool (104) that is constructed and arranged to work together with the first training tool (106, 206); Y a press set for driving at least one of the first and second 10 training tools; characterized in that the first forming tool further comprises third and fourth surfaces of the tool (216, 218) for the formation of first and second notches of the break line (298, 300). 12. A set of tools, as claimed in claim 11, wherein the second surface of the The tool (210) is constructed and arranged to form the notch of the flexion line (280) with a linear portion (304, 308) and a curved portion (306, 310). 13. A set of tools according to claim 12, wherein the first training tool (206) is constructed and arranged to ensure that the end panel (52) has a diametral axis of symmetry (282) that intersects a center point of the mustache notch (278), and in which the notch of the bending line (280) 20 is symmetric about the diametral axis of symmetry (282).