U.S. patent application number 11/089591 was filed with the patent office on 2006-01-26 for anti rotation bead.
Invention is credited to Richard Chalk, Martin Gray, Hajo Rieck.
Application Number | 20060016815 11/089591 |
Document ID | / |
Family ID | 35656032 |
Filed Date | 2006-01-26 |
United States Patent
Application |
20060016815 |
Kind Code |
A1 |
Rieck; Hajo ; et
al. |
January 26, 2006 |
Anti rotation bead
Abstract
Sheet metal lid for closing can body, in which lid includes a
panel and surrounding seamable edge suitable for attaching to can
body. An openable area is defined on panel by a weakening line, and
tab is disposed on a mounting place outside openable area. Tab has
grip portion, opening portion, and attaching portion, such that
attaching portion is provided for attaching tab substantially
parallel with respect to panel, and tab is attached so that it is
disposed with its opening portion above openable area. Near to at
least one edge of attaching portion, at least one strip-shaped
projection is shaped to protrude out of panel for limiting a
pivoting movement (.alpha.) of tab around mounting place. The
instant abstract is neither intended to define the invention
disclosed in this specification nor intended to limit the scope of
the invention in any way.
Inventors: |
Rieck; Hajo; (Gelsdorf,
DE) ; Gray; Martin; (Flintshire, GB) ; Chalk;
Richard; (Flintshire, GB) |
Correspondence
Address: |
GREENBLUM & BERNSTEIN, P.L.C.
1950 ROLAND CLARKE PLACE
RESTON
VA
20191
US
|
Family ID: |
35656032 |
Appl. No.: |
11/089591 |
Filed: |
November 3, 2003 |
Current U.S.
Class: |
220/269 ;
220/254.3; 220/619; 220/906 |
Current CPC
Class: |
B65D 2517/0068 20130101;
B65D 17/4012 20180101 |
Class at
Publication: |
220/269 ;
220/254.3; 220/619; 220/906 |
International
Class: |
B65D 17/34 20060101
B65D017/34 |
Claims
1-53. (canceled)
54. A sheet metal lid for closing a can body, the lid comprising: a
panel having a weakening line defining an openable area; a seamable
edge, surrounding the panel, being attachable to the body; a tab
including a grip portion, an opening portion and an attaching
portion, such that the attaching portion is arranged for attaching
the tab substantially parallel with respect to the panel; a
mounting place positioned outside the openable area, such that the
tab is arranged on the mounting place; at least one strip-shaped
projection shaped to protrude out of the panel for limiting or
blocking a pivoting movement of the tab around the mounting place;
wherein the opening portion is arranged above the openable area,
and at least one edge of the attaching portion being proximate the
at least one strip-shaped projection.
55. A sheet metal lid for closing a can body, the lid comprising: a
panel having a weakening line defining an openable area; a seamable
edge, surrounding the panel, being attachable to the body; a tab
including a grip portion, an opening portion and an attaching
portion, such that the attaching portion is arranged for attaching
the tab substantially parallel with respect to the panel; a
mounting place positioned outside the openable area, such that the
tab is arranged on the mounting place, and the opening portion is
arranged above the openable area; the panel comprising at least one
strip-shaped projection being arranged outside the attaching
portion to block a substantial pivoting movement of the tab in a
plane parallel to the panel.
56. A sheet metal lid for closing a can body, the lid comprising: a
panel having a weakening line defining an openable area; a seamable
edge, surrounding the panel, being attachable to the body; a tab
including a grip portion, an opening portion and an attaching
portion, such that the attaching portion is arranged for attaching
the tab substantially parallel with respect to the panel, and
includes a surface or planar extension smaller than an extension of
the tab; a mounting place positioned outside the openable area,
such that the tab is arranged on the mounting place, and the
opening portion is positioned above the openable area; and the
attaching portion comprising at least one blocking element arranged
outside the extension of the attaching portion for delimiting a
pivoting movement of the tab.
57. A sheet metal lid for closing a can body, the lid comprising: a
panel having a weakening line defining an openable area; a seamable
edge, surrounding the panel, being attachable to the body; a tab
including a grip portion, an opening portion and an attaching
portion, such that the attaching portion is arranged for attaching
the tab substantially parallel with respect to the panel; a
mounting place positioned outside the openable area, such that the
tab is arranged on the mounting place; the panel comprising at
least projection for limiting or blocking a pivoting movement of
the tab by contacting at least one outer edge of the attaching
portion.
58. The lid in accordance with claim 57, wherein the at least one
projection extends over at least 30% of a width or a length of the
attaching portion.
59. The lid in accordance with claim 57, wherein the at least one
projection extends over at least 50% of a width or a length of the
attaching portion.
60. The lid in accordance with claim 57, wherein a plurality of
projections are provided near the at least one edge of the
attaching portion.
61. The lid in accordance with claim 60, wherein at least one of
the plurality of projections has a line or strip shape.
62. The lid in accordance with claim 60, wherein at least one of
the plurality of projections has an approximate round to oval
shape.
63. The lid in accordance with claim 61, wherein at least two of
the projections are not equally aligned.
64. The lid in accordance with claim 57, wherein the limiting or
blocking of the pivoting movement of the tab occurs through contact
with the at least one projection.
65. The lid in accordance with claim 57, wherein the at least one
projection is arranged between the grip portion and the opening
portion of the tab on the panel.
66. The lid in accordance with claim 57, wherein the attaching
portion is substantially rectangular in shape and having at least
three outer edge portions.
67. The lid in accordance with claim 57, wherein the attaching
portion is substantially square in shape and having at least three
outer edge portions.
68. The lid in accordance with claim 57, wherein the attaching
portion is connected to an articulation line on the tab, so that
the opening portion is tiltable in a substantially vertically
direction to a plane of the panel when actuating the grip
portion.
69. The lid in accordance with claim 68, wherein the tilting
movement causes an opening of the openable area along the weakening
line.
70. The lid in accordance with claim 57, wherein the limiting or
blocking of the pivoting movement of the tab is maintained
throughout the entire vertical tilting of the tab.
71. The lid in accordance with claim 60, wherein the plurality of
projections are arranged such that when horizontally pivoting the
tab, each of the plurality of projections engages a single edge of
the at least one edge of the attaching portion.
72. The lid in accordance with claim 57, wherein the at least one
projection has a cross section which is shaped asymmetrically in a
direction transverse to its longitudinal extension.
73. The lid in accordance with claim 72, wherein the asymmetrical
shape includes variable steep flanks or sides that are non parallel
to each other, or the asymmetrical shape includes a second steep
flank that is less steep than first steep flank so as not to extend
parallel to each other.
74. The lid in accordance with claim 73, wherein the first steep
flank is located closer to an outer edge portion of the attaching
portion than the second steep flank of the same projection.
75. The lid in accordance with claim 54, wherein the at least one
projection has a height greater than 300 .mu.m, measured from a top
side facing outwards of the panel around the projection.
76. The lid in accordance with claim 75, wherein the height is
substantially adapted to a height or thickness of a sheet metal of
the attaching portion for the limiting or blocking of the pivoting
movement of the attaching portion.
77. The lid in accordance with claim 76, wherein the height of the
at least one projection is not less than substantially the
thickness of the sheet metal at the respective outer edge portion
of the attaching portion.
78. The lid in accordance with claim 54, wherein the at least one
projection is shaped by an initial shaping or pre-forming from the
panel and is structured and arranged in a final shape by a
reshaping or reforming, so that a reduction in the thickness of a
top side of the projection is effected during reforming.
79. The lid in accordance with claim 78, wherein a first flank is
shaped more steeply than a second flank of the projection in a
reforming process.
80. The lid in accordance with claim 54, wherein the at least one
projection is located in a peripheral area of a rivet base zone in
the lid, such that the rivet base zone is visible from an inside or
a product side.
81. The lid in accordance with claim 80, wherein a part of the
projection is located outside the rivet base zone.
82. The lid in accordance with claim 81, wherein more than 40% of a
surface area of the at least one projection is located outside the
rivet base zone.
83. The lid in accordance with claim 81, wherein the rivet base
zone extends as a mounting place annularly about a rivet, which is
visible from the inside or the product side.
84. The lid in accordance with claim 80, wherein the at least one
projection is positioned as a secant to a tangent as a strip or a
line in a edge portion of the rivet base zone.
85. A sheet metal lid for attaching a tab having an attaching
portion and for closing a can body, the lid comprising: a tab
including an attaching portion attached to the lid for closing a
body; at least one panel surrounded by a seamable edge attachable
to the body; an opening area being defined by a weakening line on
the at least one panel; the at least one panel comprising a
mounting place on which the tab is attachable; and at least one
projection shaped to protrude from the at least one panel being
structured and arranged to at least limit or block a pivoting
movement of the tab through contact with at least one outer edge
portion of the attaching portion.
86. A sheet metal lid for attaching a tab with an attaching portion
and for substantially closing a can body, the lid comprising: at
least one panel surrounded by a seamable edge that is attachable to
the body; a weakening line defining an opening area on the at least
one panel; the tab is attachable on a mounting place formed on the
at least one panel; at least one projection arranged near but
removed from the mounting place by a distance corresponding to at
least to a distance of an outer edge of the attaching portion of
the tab from the mounting place, after mounting the attaching
portion.
87. The lid in accordance with claim 86, wherein the outer edge is
an edge line facing away from the attaching portion, and wherein at
least two edge lines limit a surface extension of the attaching
portion.
88. The lid in accordance with claim 86, wherein said at least two
edge line portions have a substantially straight-lined
extension.
89. A method for shaping the sheet metal lid in accordance with
claim 86, comprising: (A) shaping a pre-form of the projection out
of the panel such that the pre-form is located near the attaching
portion of the tab, but at a distance from the mounting place; and
(B) re-forming a front edge of the at least one projection, for
obtaining a better blocking for an associated outer edge portion of
the attaching portion.
90. The lid in accordance with claim 89, shaping the pre-form of
the at least one projection, followed by a score line shaped into
the at least one portion of the panel.
91. The lid in accordance with claim 90, re-forming includes an
embossing by which a top side of the at least one projection is
flattened and stiffened.
92. The lid in accordance with claim 91, wherein the method
includes a stiffening having a reduction of a sheet metal thickness
by at least 10%.
93. The lid in accordance with claim 57, wherein the projection has
the length of more than 80% of the width of the attaching
portion.
94. The lid in accordance with claim 54, wherein a plurality of
projections are located near at least one portion of two or more
edges of the attaching portion.
95. The lid in accordance with claim 60, wherein the at least one
projection extends in a longitudinal direction of the tab and has a
length that is not more than 50% of a longitudinal extension of the
attaching portion, and in combination with a distance of the
outermost end of the at least one projection from a center of the
mounting place of the more than 50% of the longitudinal extension
of the attaching portion.
96. The lid in accordance with claim 60, wherein at least three
projections are arranged, two of which extending substantially
parallel to a longitudinal axis of the tab and one extending
substantially perpendicularly to the axis.
97. A sheet metal lid comprising: a panel portion coupled to an
attachable tab through a substantially flat attaching portion of
the tab; a mounting element on which the tab is arranged; at least
one projection extending upwards from the panel portion which is
structured and arranged with at least one front stop edge for at
least limiting or blocking a horizontal rotation movement of the
tab.
98. The lid in accordance with claim 97, wherein the mounting
element is on a rivet integrally formed with the panel portion.
99. The lid in accordance with claim 97, wherein the at least one
front stop edge is linear.
100. The lid in accordance with claim 97, wherein the at least one
front stop edge extends over more than half of a width or at least
30% of a length of the flat attaching portion.
101. The lid in accordance with claim 97, wherein the at least one
front stop edge is substantially perpendicular to a longitudinal
plane extending along a length of the tab.
102. The lid in accordance with claim 97, wherein the at least one
projection is formed by; (A) forming a front stop zone from a
portion of the panel, and (B) re-shaping the stop zone into a shape
which has a stop edge or re-shaping the stop zone into a shape
which has the stop edge that is steeper or sharper than the stop
zone shaped previously.
103. The lid in accordance with claim 97, wherein at least two stop
edges are provided substantially parallel to a longitudinal plane
extending along the length of the tab.
104. The lid in accordance with claim 98, wherein the at least one
projection from the panel is shaped in an area corresponding to a
periphery of a rivet base portion or an embossed portion around the
mounting place.
105. The lid in accordance with claim 97, wherein the at least one
projection is flattened on a top side thereof, and having a wall
thickness being reduced thereof.
106. The lid in accordance with claim 105, wherein the reduction is
provided by an embossing operation.
107. The lid in accordance with claim 105, wherein a steeper edge
of the at least one projection comprises at least one portion
extending at an angle of substantially 90.degree. with respect to
the panel.
108. The lid in accordance with claim 97, wherein the at least one
projection or the at least one stop edge has a greater width than a
height and a greater length than width.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to the provision of a positional
fixing of a tab on a sheet metal lid for attaching to a body of a
beverage can.
[0003] 2. Discussion of Background Information
[0004] Tabs which are also called Stay on Tabs, e.g., SOT, are
attached to sheet metal lids and are known devices for opening
beverage cans, so a consumer can gain access to a liquid within the
beverage can. When the tab is in an attached condition to the sheet
metal lid of the beverage can the tab provides for a consumer to
open an openable area in the surface of a lid (usually designated
as "panel"). For example, the tab is taken at a grip end of the tab
and raised with a vertical tilting motion, so as to break open the
openable area of the lid along a line of weakness (usually called
score line).
[0005] Particularly when large opening ends (LOEs) are used for the
openable area, difficulties are encountered in the related art when
arranging the positioning of the tab along the line of weakness (or
score line), when the tab is in an attached condition to the sheet
metal lid. U.S. Pat. No. 5,799,816 (Schubert) attempts to deal with
the above problem, by arranging an attaching portion (or "rivet
island") of the tab to be secured to the panel of the sheet metal
lid through a shaped rivet. The shaped rivet provides for an
anti-rotation feature which maintains proper alignment of the tab
and particularly its nose portion, so as to minimize failed
openings. See FIGS. 2 and 4 and Col. 3, lines 63-67 and Col. 5,
lines 37-44 of Schubert.
[0006] The instant invention addresses the technical problems
related to the positional alignment of the tab in the attached
condition, as well as the manufacture and reliability of the
anti-rotation block.
SUMMARY OF THE INVENTION
[0007] The present invention improves the positional alignment of a
tab in an attached condition arranged on a panel, as well as
improve the manufacture and reliability of the anti-rotation
block.
[0008] According to one feature of the invention, a sheet metal lid
can be used for closing a can body. The lid may include a panel
portion and a seamable edge that surrounds the panel, so the edge
can be adapted for attaching to the can body. An openable area
defined on the panel includes a weakening line, wherein a tab can
be disposed on a mounting place outside of the openable area. The
tab embodied according to the invention may include a grip portion,
an opening portion, and an attaching portion. The attaching portion
can be provided for attaching the tab substantially parallel with
respect to the panel, such that the tab as attached is disposed
with its opening portion above the openable area. Further, near the
at least one edge of the attaching portion, at least on
strip-shaped projection can be shaped to protrude out of the panel
for a limiting pivoting movement (.alpha.) of the tab around the
mounting place.
[0009] According to another feature of the invention, the
projection need not protrude through an opening in the attaching
portion, and the attaching portion does not need to be provided
with an opening for the above purpose. Instead, the attaching
portion can be kept whole, and a blocking element is provided to
act on the attaching portion from an outside arrangement.
[0010] In order to obtain the blocking effect, which may also be a
limiting effect, --or to completely prevent a rotating movement of
the tab up to a substantial limit of the rotating movement, an
outer edge of the flat attaching portion (rivet island) abuts
against the projection that is shaped to protrude out of the sheet
metal lid. Since the projection has positional stability on the
panel in all operating positions, even when starting to break open
the openable area, and since the attaching portion is substantially
coplanar with the panel of the lid, tightly surrounding the central
rivet as a mounting place, none of the above elements provided for
preventing rotation operationally moves apart with an opening
movement of the tab. Since the opening movement is a vertical
tilting motion, anti-rotation is unaffected due to an outer edge of
the attaching portion abutting on the panel projection.
[0011] Advantageously, a peripheral edge on a known tab within the
art may also be used, since the edge does not have to be
specifically arranged for obtaining the rotation barrier effect
after the attachment of the tab to the panel ("staking"). The only
manipulation is effected on the sheet metal lid itself, which is
provided with a shape, as is the rivet in a preliminary phase,
which shape may preferably also be pre-formed together with the
formation of the rivet and modified in shape, or more precisely
"reformed" subsequently, in a further processing step of the sheet
metal lid being manufactured. The projection may thus be formed
integrally with the sheet metal lid, as is the mounting place by
one-piece manufacturing for the attaching portion of the tab.
[0012] The projection may have a strip shape (or line shape)
aligned transversely and/or parallel to a longitudinal extension of
the tab (e.g., longitudinal axis or longitudinal plane), engaging
at a correspondingly aligned peripheral edge of the attaching
portion for its blocking effect. In a longitudinal extension, the
projection may extend over more than 30%, 50%, or possibly to more
than 80% of the width of the attaching portion.
[0013] If the projections extend parallel to the longitudinal
extension of the tab, or perpendicular to the transverse direction
mentioned above, than the longitudinal extension may be shorter
than the longitudinal extension of the attaching portion (rivet
island) of the tab. Further, the projection may be at a position as
distant as possible from the mounting place, such that at least one
portion of the two peripheral lines mentioned above, abuts and
prevents rotation on the at least one projection when starting a
rotating movement.
[0014] Arranging the attachment portion as distant as possible from
the mounting place allows the greatest possible force to be
exerted, which provides a blocking effect to prevent rotation of
the tab by a user. In particular, the projections oriented parallel
to the longitudinal extension of the tab allows for a great force
to be applied for the locking effect. All three of the above
structural arrangements may be used either singularly or used in a
combination.
[0015] The height or vertical extension of the at least one
projection, may be at least equal to or possibly greater than the
thickness of the sheet metal of the attaching portion, in order to
obtain a reliable fixing position. Further, the above arrangement
does not impair the operating or raising the grip portion, since
the attaching portion is reliably situated on the other side of the
mounting place and coplanar with the panel section surrounding the
rivet (button coin area).
[0016] Several projections may be provided, but not all projections
have to be assigned to the same outer edge portion of the attaching
portion. The projections may also be differently embodied, i.e.
strip-shaped, round to oval, or a combination thereof. If a
line-shaped outer edge portion of the attaching portion is
provided, a line-shaped (strip-shaped) embodiment of the
projections may be advantageous. The line-shaped strip design may
also be achieved by arranging at least two punctiform projections
in line, which then form a group that is assigned to the same outer
edge portion of the attaching portion.
[0017] The attaching portion in the form of a mounting tongue can
be connected to the rest of the tab via a buckling portion in the
form of an articulation line, i.e. integrally. It is thus provided
between the opening portion (the rupture nose) and the grip portion
which can be provided with a hole.
[0018] If the attaching portion is substantially rectangular, the
substantially rectangular, flat, attaching portion can be formed by
using the articulation line and three edge lines. Particularly, the
flat or surface portion can be square in shape, and the rivet head
positioned closer to the articulation line, so as not to be
centrally arranged after mounting. The distance of the outwardly
directing peripheral edge can therefore be larger than half the
longitudinal extension of the attaching portion, so that a
correspondingly improved force effect is achieved when a projection
on the panel can be assigned to the peripheral edge farthest from
the mounting place.
[0019] Further, it is possible for at least one of the projections
to have an asymmetrical cross section, so as to have a steeper
flank facing the attaching portion than the flank facing away from
the attaching portion. The above configuration may also be selected
for example, for the punctiform or oval projections.
[0020] According to another feature of the invention, a subsequent
reshaping, reforming, or post-forming may include the reduction of
the thickness of a top side of the (strip-shaped) projection, thus,
achieving the solidification of the portion together with the
projection as a whole. The score line may also be applied
simultaneously with the reforming as mentioned above.
[0021] The result of reforming can be visually apparent in a
flattened top side. Thus, the projection mentioned above can have a
larger width than its total height. Further, the respective
longitudinal extension of a projection can be considerably larger
than the width of the projection. This can apply to elongated
strip-shaped or line-shaped projections. When a steeper flank
portion is formed it can be more pronounced than the preform.
Further, a peripheral edge may be obtained having (at least) one
portion extending at an angle substantially 90.degree. relative to
the plane of the panel. This applies to the edge opposing the
assigned peripheral edge portion of the attaching portion. An
embossing process also helps to give a stronger or steeper shape to
the flank, the embossing provides for the reinforcement of the
reformed sheet metal on the top side.
[0022] Further, if several projections are provided they do not
have to engage the same edge line of the attaching portion at the
start of a rotating movement, but instead may be assigned to
different outer edges.
[0023] A still unfinished sheet metal lid is prepared to receive a
tab includes the formation of the projection that is sufficiently
positioned to be distant from the intended mounting place (from the
re-formed rivet or its preform). Further, at such a distance the
outer edge in the form of an edge of the attaching surface (rivet
island) facing away from the future rivet can be located very close
to the projection, thereby achieving the rotation stopping effect.
Furthermore, since the location is in the outer edge portion of a
rivet head zone or the "rivet base", it can extend visibly around
the formation of the rivet center remaining from the rivet
perform.
[0024] The projection arranged as a line or strip can be positioned
at least partially outside the weakened rivet base portion, in
which the sheet metal may be thin due to the shaping of the
mounting place. The above arrangement can address a peripheral
portion of the rivet base zone which may be more than 40% of an
assumed surface of a strip-shaped projection lying outside the
rivet base zone.
[0025] The rivet base zone can be arranged to visibly change the
surface remaining on the inside of the sheet metal lid after the
rivet has been formed and the tab has been mounted. Since the
projection is placed in the outer portion, i.e. as distant as
possible from the weakened sheet metal or the thin sheet metal, the
re-formed portion may be considerably higher before the sheet metal
is damaged. Further, the re-forming may achieve heights that can be
above a sheet metal thickness of the attaching portion of the
tab.
[0026] The projection may be provided with a strip shape, as well
as be designed to have a length longer than the diameter of the
finished rivet head.
[0027] The attaching portion can be formed from a piece of the
central portion of the tab, in which only minor gaps are visible
between the attaching portion, which is displaced downwards to a
lower plane by a double buckling line, and the parallel plane of
the rest of the tab, which may be somewhat higher. Accordingly, the
mounting of the projections on at least one of the free peripheral
edges facing outward from the attaching portion may be barely
visible from the outside, so that the rotation blocking is
virtually invisible to the observer. A colored tab does not
necessarily have to change in a colored shape.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The present invention is further described in the detailed
description which follows, in which like reference numerals
represent similar parts throughout the several views of the
drawings, and wherein:
[0029] FIG. 1 shows the first stage of three stages in a
manufacturing process of a sheet metal lid, which introduces, in
part, a score line or weakening line, U-shaped bead and mounting
place;
[0030] FIG. 2 shows the second stage of three stages in a
manufacturing process of a sheet metal lid, which introduces, in
part, beads along the tab, finger depression and an eyeball shaped
bead;
[0031] FIG. 3 shows the third stage of three stages in a
manufacturing process of a sheet metal lid, which introduces, in
part, an attaching tongue, tab, buckling line and open
position;
[0032] FIG. 4 is an enlarged section from FIG. 3, particularly
showing the attaching portion 31 and the rivet 11 as mounting
place;
[0033] FIG. 4a is a cross section along line C-C in FIG. 4;
[0034] FIG. 5 is an alternative configuration for the positional
fixing of attaching portion 31 and thus of the entire tab 30;
[0035] FIG. 5a is a sectional view through the center plane of FIG.
5, alternatively through the vertical longitudinal plane 100 of
FIG. 3;
[0036] FIG. 6 is an alternative arrangement of projections for
blocking rotation of the tab;
[0037] FIG. 7 is another alternative arrangement to FIG. 6;
[0038] FIG. 8 is a cross section along a longitudinal plane 100, to
illustrate a sharp front edge 20a of a strip-shaped or line-shaped
projection 20;
[0039] FIG. 8a is a cross section of an embodiment of the invention
corresponding to the illustration in FIG. 8;
[0040] FIG. 9a is a schematic explanation of the effective torques
in a projection extending parallel to the center plane 100;
[0041] FIG. 9b is a comparable explanation of the effective torques
in a projection 20 located transversely to the center plane 100;
and
[0042] FIG. 10 is an illustration of a portion 11a around a rivet
11, the portion being visible from the inside of the lid, a
projection 20 being visible as an outwardly vaulted cavity. This
figure identifies only a section around a rivet 11 as a mounting
place.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
[0043] FIGS. 1 to 3 show a sheet metal lid having a visible edge
portion 12 suitable for seaming to a body of a beverage can. The
sheet metal lid can be produced from thin sheet metal, typically
less than 0.24 mm, which may have already passed through previous
workstations before reaching the stage shown in FIG. 1. Further,
the lid may include an inner surface portion or panel 10 that can
be surrounded by a seamable edge 12. Further, within the panel 10,
a weakening line 16 can be provided around an openable area,
wherein the openable area may be surrounded by a substantially
U-shaped bead 18. The bead opens towards the center portion of the
panel, wherein the substantially O-shaped weakening line 16 is
designed as a score line. A transitional section that is not scored
serves as a connecting portion to the rest of panel 10, when the
openable area 17 is broken in and along the score line 16 by the
effect of a tab.
[0044] A mounting place 11 is positioned approximately in the
middle of the panel. An attaching portion 31 or a sheet metal
tongue can be part of the tab (FIG. 3), which can be integrally
formed via an articulation line or a buckling line 38. The tab 30
can include a grip portion 32 that may be arranged with a circular
opening, so the tab 30 can be operated by the user for breaking
open the score line 16. See FIG. 1. The tab 30 may also include an
opening portion 33 arranged before the attaching portion 31,
wherein the opening portion may be located as a rupture nose above
the openable area 17. Further, an additional eyeball-shaped bead
18a (FIG. 2) can be provided to reinforce the transverse LOE (large
opening ends) openable area, resulting in an arrangement in which
the applied forces from the opening forces are able to rupture the
starting portion or arcuate end of the score line 16. The mounted
tab 30 may be substantially parallel to the panel, so as to be
slightly bulged or not exactly arranged in one place, through an
area around the mounting place 11. Further, the mounting place 11
can be substantially planar so as to allow for a substantially
parallel arrangement of the attaching tongue of the tab 30.
[0045] FIGS. 1, 3 and 5 show the longitudinal midplane 100
extending in a direction to the longitudinal extension of the tab
30, as well as a transverse plane 101 (FIG. 5) extending
perpendicularly thereto.
[0046] The grip portion 32 (of an attached or staked end) of the
tab 30 overlaps a finger depression 13, which is provided in the
panel 10, at approximately the same distance as the inner
reinforcing bead 18a on the other side of mounting place 11. The
tab 30 may only be attached (FIG. 3) during the manufacture of the
finished sheet metal lid. Prior to the completion of manufacture of
finished sheet metal lid, the mounting place 11 may initially be
formed as a bubble to permit the attaching portion 31 of the tab 30
to be attached to the panel 10. FIG. 1 shows three strip-shaped
projections 20, 21 re-formed as upwardly protruding beads (i.e.
towards the outside of the sheet metal lid) around said mounting
place 11. The bead 20 can extend transversely to the midplane 100
which may be longer than the two neighboring beads that can extend
parallel to the midplane 100. FIG. 4 shows detailed view via 21a,
21b of a possible arrangement of the longer bead 20 with respect to
the attaching tongue 31.
[0047] FIG. 1 shows the attachment tongue 31 and the distances of
the beads 20, 21 from the mounting place 11. At a particular
manufacturing station, the re-forming of the three beads 20, 21a,
21b results in a formation of the beads (or projections). See FIG.
3. At the above manufacturing station, the projections are
re-formed integrally from the sheet metal lid or panel 10 so as to
extend in a vertical direction at least to a height h that is equal
to the sheet metal thickness of the attaching portion 31 of the tab
30. Further, the projections are then provided with correct profile
geometries.
[0048] FIG. 3 shows the rivet head in a forming process with a
larger diameter than is shown in FIGS. 1 and 2, wherein the tab 30
is placed over the rivet shaft. While the rivet head is forming,
the tab 30 is attached to the panel 10 via the attaching portion
31, wherein the attaching portion 31 can be connected to the rest
of the tab 30 through a buckling line 38. The opening section 33
can be located above the openable area 17 inside the score line 16,
close to an additional stiffening bead 18a.
[0049] In order to ensure the rupture force and the accuracy in the
breaking-open process, the tab 30 rotational movement direction is
designated by .alpha. in FIG. 4.
[0050] To open the opening area 17, the front nose end of the
opening portion 33 is moved away from an exact position to provide
a rupture force, resulting in continued tearing until the
subsequent complete opening of the opening area 17. It is obvious
that the front nose end of the opening portion 33 would be moved
away from the exact position that is provided to ensure the rupture
force, the continued tearing and the subsequent complete opening of
the opening area 17.--FIG. 4 shows the tab rotational movement
.alpha. being as minimal as possible, or possibly restricting all
rotational movement. FIGS. 4-6 show the three strip-shaped
projections 21a, 21b and 20 being assigned to the three free
peripheral edges 31a, 31b, 31c of the attaching portion 31 of the
grip portion 30. A small gap 21', 21'' and 20' may be left between
each outwardly facing edge and the respective inner edge of the
each projection, for example, 31c from 20'' at the projection 20.
However, the gap may also be reduced to zero on at least one of the
outwardly facing edges of said attaching portion 31.
[0051] FIG. 4 shows the width of the attaching portion 31 being
marked with "b", and the two projections 21b, 21a (or beads)
positioned parallel to the longitudinal midplane 100 and at a
distance from the attaching portion 31 via inside edges 21b' and
21a'. The longitudinal extension of the attaching portion 31 in the
plane 100 extends over the rivet head as the mounting place 11. The
length of the two beads 21a, 21b can be shorter than half the
longitudinal extension of the attaching portion 31. Further, beads
may be positioned as far as possible to the rear area of the
attaching portion in order to apply the greatest possible force for
the locking effect or positional fixing with an assumed rotation
movement .alpha..
[0052] The above arrangmement of the locking effect (or positional
fixing) with the assumed rotation movement .alpha., may further be
effected with the greatest possible distance of the projection 20
disposed in the transverse plane 101, which is transverse to the
longitudinal mid-plane 100. Further, the projection 20 may be
longer than two projections 21b, 21a (or beads) positioned parallel
to the longitudinal midplane 100. It is possible for the projection
20 to extend over more than half or even more than 80% of the width
b of the attaching portion 31.
[0053] According to another feature of the invention, it is also
possible for one or more of the three strip-shaped projections or
beads described above to be omitted from the attaching portion
31.
[0054] According to another embodiment of the invention, the
attaching portion 31 may be arranged with one projection 20, as
viewed in FIG. 5. Further, the outwardly facing edge 31c is
positioned farthest from the rivet or mounting place 11 and
approximate the strip-shaped projection (or geometry) 20, so as to
minimize or even prevent the rotational movement .alpha. of the tab
30. It is possible to limit the rotational movement .alpha. of the
tab 30 with the positioning of the projection 20 to such an extent
that the opening behavior of the tab is not affected when the tab
30 is tilted upwards at the grip portion 32. The rotating movement
.alpha. can be predetermined by at least two limit values, which
are defined by the abutment in an assumed rotation .alpha. (in both
directions about the axis of the rivet 11), resulting in limited or
even possibly no rotating movement .alpha.. Further, the rotational
or pivoting movement .alpha. is substantially in the plane in which
the panel is disposed in an area surrounding the rivet head 11,
such that the plane is kept parallel by the plane of the attaching
portion 31 (which may have a planar or surface extension). The
attaching portion 31 may be embodied as a rectangle or square,
having two parallel peripheral edges or edges 31b, 31a and one
peripheral edge 31c at a distance from the articulation line 38 and
extending parallel thereto. Another embodiment may include the
attaching portion 31 having an arcuate form similar to a triangular
shape, or a more distant shape which may not have a straight
extending peripheral edge 31c.
[0055] The cross-section shown in FIG. 4a relates to the
corresponding sectional line of FIG. 4. According thereto, an
asymmetrical design of the strip-shaped projections 21a, 21b is
provided, a steeper flank 21b' being located closer to a peripheral
edge 31b than the less steep flank 21b'' of strip-shaped projection
21b. The same is valid for the parallel projection 21a and its
associated peripheral edge 31a.
[0056] In FIG. 4a, the sheet metal lid in the panel 10 and the
attaching portion 31 are parallel, with the rivet 11 (not shown).
An assumed rotation movement causes the peripheral edge 31a to abut
on the steeper flank of the projection 21a, or the peripheral edge
31b to abut on the steeper flank 21b' of the projection 21b. A
narrower association of the steeper flanks, due to their almost
vertically extending ridges or steps, permits any minor (residual)
rotating movement in the plane of the sheet metal lid of the panel
10 in the rivet zone 11 to be almost completely prevented.
[0057] FIG. 5a shows a cross section relating to FIG. 5 and
arranged through the longitudinal plane 100. FIG. 5a shows one
projection 20 cooperating with the peripheral edge 31c of the
attaching portion 31 to prevent function-affecting rotational
movements .alpha.. Further, the rivet head designed as a mounting
place 11 is visible through an opening in the attaching portion 31.
Also visible is the allocation of the free peripheral edge 31c to
the projection 20 re-formed from the metal sheet lid, which
projection 20 (see FIG. 4a) indicates that other projections 21b,
21a may also have an asymmetrical shape.
[0058] FIG. 8 shows the asymmetry in a transverse direction to the
longitudinal extension of the projection 20 (in the longitudinal
plane 100 of the lid or the tab). Further, the projection 20 can be
associated to the peripheral edge 31c of the attaching portion 31.
By a double forming process, a first pre-forming according to FIG.
1 and a second re-forming according to FIG. 2, resulting in a very
steep front edge 20'' or 20a can be obtained, having a very large
height h (relative to the thickness of the sheet metal).
Furthermore, the projection 20 is arranged as distant as possible
from the sensitive area of the rivet base 11a, in case the sheet
lid is damaged which would resulting in damage to the projection
20. The steep front edge 20a (or 20'' according to FIG. 4),
together with a less steeply extending second flank 20b, which
provides no blocking effect with the attaching portion 31, allows
higher forces to be applied. Further, the attaching portion 31 is
less likely to be deformed upwards (perpendicularly to the plane of
panel 10) on a more flatly extending peripheral edge and to thereby
lose the blocking effect.
[0059] FIG. 8a shows the cross section extending in a longitudinal
direction, as determined by the longitudinal midplane 100 for FIG.
4, 5, 8 as viewed in the bottom section. Further, the top
illustration shows a preform 20*, in a two-stage manufacturing
process prior to the second step (post-forming or re-forming). In a
first shaping step, for example according to FIG. 1, a pre-form
20*, which may have a rampart (or ridge-shaped structure), can be
shaped to protrude out of a panel 10 with two flat inclines and a
middle portion extremely rounded. In a second re-forming step, (see
FIG. 2), a much steeper front edge 20'' (see FIG. 4) or 20a (see
FIG. 8) is obtained, while the sheet metal lid nevertheless remains
undamaged. The second re-forming and the result after attaching the
grip portion are shown in the lower illustration of FIG. 8a. It is
understood that in both the upper and the lower illustrations, the
strip-shaped projection 20 can extend perpendicularly to the paper
plane, in a transverse plane 101 extending perpendicularly to the
longitudinal midplane 100. The transverse plane 101 is a relative
indication referring to the position of the pre-form 20*, in which
there is a symmetry of the pre-form initially shaped from the sheet
metal lid relative to the plane 101, that is abandoned during
re-forming, as is illustrated by the finished projection 20 in the
bottom representation, in which it is no longer symmetrical to the
transverse plane 101.
[0060] The following embodiments refer to the bottom illustration
of FIG. 8a. The rivet 11 used for attaching portion 31 to the sheet
metal lid 10 can be located to the left (not shown). A rear end 31c
of an attaching portion 31 is the peripheral edge that is assigned
to a front edge 20'' of a projection 20, possibly leaving a narrow
gap 20' (see FIG. 4). The projection 20 is characterized by an
asymmetry, with a steep front edge 20'' (or 20a) and a less steeply
extending peripheral edge 20b facing outwards. As a result of
re-forming, the projection may also have a plateau-shaped top side
20c, providing for the projection 20 to reach a very large height h
relative to the thickness of the sheet metal, despite the
relatively flat appearance of its shape. However, the width of the
projection is arranged to have an increased strength with the width
being larger than its height h, particularly about twice as wide as
it is high, so that the essential portion of the projection 20 can
be situated to the right of the transverse plane 101.
[0061] The re-forming step includes shaping the pre-form 20* with a
coining (or an embossing operation) for flattening the top surface
20c. In the re-forming process, a tool is applied from the top and
from the bottom for re-forming. The slight bend that is detectable
on the left in the rising flank of the pre-form 20' may be
recognized in the bottom final form via the sharp front edge 20''
being introduced in the initially gently rising front incline of
the shaped rampart 20*. To the right of the transverse plane 101,
the second incline of the rampart is formed from bottom to top, for
forming a flat shape 20c, starting approximately at the instep of
said rampart 20* and leading gently over to the rest of the sheet
metal panel 10 in portion 20b.
[0062] Additionally, in the final form, the attaching portion 31
and the tab 30 are already attached according to FIG. 3. The tab
can be arranged with its intermediate web between the left opening
and the grip opening 32b substantially above the transversely
extending projection 20. The two openings of the tab are shown in
figure 3, one opening resulting from the formation of the attaching
portion 31, which is further connected to the tab 30 via an
articulation line 38, whereas the opening for inserting a finger is
designed particularly. The opening 32b is a part of the grip
portion 32, the web 32a between said two openings being shown
slightly bulged in FIG. 8a, having a front edge 32c that was
related to the free edge 31c of the attaching portion 31 during
manufacture. A major part of the projection 20 is thus located
below said web and is barely visible from outside.
[0063] In this context, a modified sequence of the two-stage
re-forming may be performed besides the processing sequence
according to FIGS. 1 to 3. For example, the initial introduction of
the pre-forms, as illustrated by the pre-form 20* in the top
picture of FIG. 8a, in a first working step, shown without the
introduction of score lines (as weakening lines 16). In this case
multiple projections can be used to block rotating movements which
may include all the pre-forms being shaped. The first score line
introduced can be jointly in a single working step, in which the
re-forming (further shaping) of the pre-formed projections takes
place. In this step, the projections receive their correct,
assigned profile, as is shown in the bottom illustration of FIG.
8a. For example, this profile is capable of being transferred not
only to the transversely extending projection 20, but also to the
other projections, provided that they have been shaped as pre-forms
in the previous operation. In this way, a scoring operation, which
subjects the sheet metal to severe stress, is not performed at the
same time as the shaping of the pre-form takes place in the first
operation, since the shaping process causes considerable stress to
the sheet metal lid. The score line may be introduced
simultaneously with the re-forming operation. During re-forming
(see FIG. 8a), the wall thickness on the top side of the projection
is reduced by about 10% to 15%, with simultaneous compression and
solidification of the same portion, thus achieving uniformity from
top to bottom by the embossing operation (or coining).
[0064] FIG. 6 shows an attachment of two substantially punctiform
projections 23a, 23b to the longitudinal sides 31a, 31b of the
attaching portion 31. Additionally, a projection 22 may be provided
on transverse edge 31c of the attaching portion 31, wherein the
projection 22 may be elongated (such as oval shape) and or
substantially circular shape.
[0065] FIG. 7 shows a group of projections arranged to a single
outer edge (outwardly facing peripheral line) of the attaching
portion 31. The group 24 may include three individual,
substantially punctiform projections assigned to the peripheral
edge 31c, but may as well be assigned to the two other peripheral
edges 31a and 31b. Also, only two punctiform projections can be
used in FIG. 7. In the same way, the asymmetrical shape of the
projections formed to protrude in upward direction in accordance
with FIG. 4a, or also FIG. 5a or 8a, may also be applied to the
above mentioned embodiments.
[0066] For example, one projection may be used with a peripheral
edge 31c extending transversely to the longitudinal plane 100 of
the tab 30, wherein the rotational movement in both directions can
be prevented if the projection extends at least on both sides of
the midplane. On the other hand, if a projection is arranged on a
peripheral edge extending parallel to the longitudinal plane 100,
then at least two projections should be provided on the two
correspondingly available edges as "stop edges", for symmetrically
limiting rotational movements of the tab 30.
[0067] All the projections described may be arranged outside the
attaching portion 30, in order to be able to cooperate in a
blocking manner with at least one of its respective outer
peripheral edges (edge).
[0068] FIGS. 9a and 9b show a top view of the attaching portion 31
disposed on the panel 10 over a mounting place 11 (or rivet head).
A lateral projection 21a extends parallel to the midplane 100 of
the tab 30, upon which a force is exerted on the projection due to
an assumed rotation movement in a direction .alpha.. An assumed
length I of the attaching portion 31 to the mounting place 11 can
be located closer to the articulation line 38 than to the rear end
31c of the attaching portion 31, so that an effective power arm
I.sub.1 is larger than half of the length I of the attaching
portion 31. Because of the positioning of the line or strip-shaped
projection 21a that is close to the rear edge line 31c, a force via
a large lever arm can apply a large torque for blocking (blocking
moment) an undesired rotation.
[0069] Similarly, the exertion of torques may be explained in a
projection 20 that extends perpendicularly to a midplane 100,
wherein the projection can substantially occupy the entire width b
of the attaching portion 31 near to a rear edge line 31c thereof.
In this case, the (maximum) power arm is designated b1, and in a
first approximation, the lever arm is approximately (but not
exactly) equal to half of the width b, marked as lever arm b.sub.1
in an assumed (hypothetical) rotational movement in a direction
.alpha. as illustrated. The corresponding force via the lever arm
b1 is applied by the projection 20, or the front edge 20a thereof
(edge 20'' in FIG. 4). The corner of the attaching portion 31 being
slightly rounded, the entire half of the width is not available for
use as a lever arm, but instead between 70% and 100% of b/2,
substantially in the range of between 80% and 90%.
[0070] FIG. 10 shows a thinned zone of the sheet metal lid around a
rivet head 11 said zone being visible from the inside. Said rivet
base zone 11a is a zone that remains on an outer side after the
second re-forming of the rivet head 11, usually visibly by circular
lines surrounding the center of the rivet as mounting place 11.
[0071] The "button coin area" most likely cannot withstand strong
stresses, since the sheet metal is reduced in thickness due to the
rivet being shaped to protrude in an outward direction. Projection
20 occupies a surface area f.sub.20 that is line or strip-shaped
mounted in the outer edge zone 11b of the rivet base, or rather
displaced far outside of the thin sheet metal zone susceptible to
possible damage. The attaching portion 31 is marked by a dashed
line showing the relative position of the "coin area".
Alternatively or cumulatively, the projection 20 can be shown as
located at the rear edge 31c, where the two lateral projections
21a, 21b may also be provided. Which can result in the projections
being positioned close to the peripheral zone of the rivet base and
not displaced to the thinned out portion near the rivet head, which
portion is susceptible to damages.
[0072] For example, a more precise dimensioning of the surface
areas may show the strip-shaped projection 20 situated at least
partly outside the rivet base zone (or coin area) and outside the
outer peripheral portion 11b thereof. The outward displacement can
be equal to at least 40% of the surface portion f.sub.20, which is
no longer in the periphery 11b of the rivet base 11a, but outside
thereof. This position and the position and extension of the coin
area can easily be visible from the inside of the sheet metal
lid.
* * * * *