U.S. patent application number 11/274519 was filed with the patent office on 2007-05-17 for container end closure with pull tab.
This patent application is currently assigned to SPARKTAB INC.. Invention is credited to Robert G. Dickie.
Application Number | 20070108208 11/274519 |
Document ID | / |
Family ID | 38039702 |
Filed Date | 2007-05-17 |
United States Patent
Application |
20070108208 |
Kind Code |
A1 |
Dickie; Robert G. |
May 17, 2007 |
Container end closure with pull tab
Abstract
An easy opening end closure for a container has a central panel
with a tear panel defined by a score line. A pull tab is attached
by a rivet to the central panel and has a nose end for engaging the
tear panel and an opposite lift end for pivoting the tab about the
rivet to fracture the score line. One or a pair of crescent-shaped
protrusions are formed on the central panel closely adjacent to and
rearwardly of the rivet to reduce the lift force required to
initially lift the lift end of the tab to start the fracturing of
the score line. The protrusions are concentric to each other and
partially circumscribe the rivet and are located beneath the pull
tab or within openings of the pull tab to avoid interference with
can making equipment and with the pull tab. The protrusions provide
greater flexibility to the area of the central panel adjacent the
rivet to enable the rivet to pull slightly upwards from the panel
at the start lifting the lift end of the tab.
Inventors: |
Dickie; Robert G.;
(Newmarket, CA) |
Correspondence
Address: |
SAND & SEBOLT
AEGIS TOWER, SUITE 1100
4940 MUNSON STREET, NW
CANTON
OH
44718-3615
US
|
Assignee: |
SPARKTAB INC.
King City
CA
|
Family ID: |
38039702 |
Appl. No.: |
11/274519 |
Filed: |
November 15, 2005 |
Current U.S.
Class: |
220/269 ;
220/906 |
Current CPC
Class: |
B65D 2517/0011 20130101;
B65D 17/4012 20180101; B65D 2517/007 20130101; B65D 2517/0071
20130101 |
Class at
Publication: |
220/269 ;
220/906 |
International
Class: |
B65D 17/34 20060101
B65D017/34 |
Claims
1. An easy open end closure for a container comprising: a central
panel having a product side and a public side and a tear panel
defined by a score line wherein said tear panel is to be at least
partially separated from the central panel to form an opening in
said end closure; a rivet disposed on the central panel; a pull tab
hingedly secured to the rivet, said pull tab having a nose at one
end overlying the tear panel and a lift end on an opposing end, a
crescent-shaped opening formed in the top surface of the pull tab
adjacent the rivet; and one of a first crescent-shaped protrusion
and depression formed in the central panel proximate the rivet and
disposed within the crescent-shaped opening formed therein.
2. The end closure defined in claim 1 wherein the pull tab opening
includes a pair of openings including an arcuate inner opening and
an outer opening separated by a cross member.
3. The end closure defined in claim 2 including one of a second
crescent-shaped protrusion and depression formed in the central
panel located concentrically with respect to the first protrusion
and lying beneath the cross member of the pull tab.
4. The end closure defined in claim 3 wherein the second protrusion
is located a distance of approximately 0.25 inches from the rivet
measured between the center of the rivet and the top center of said
second protrusion.
5. The end closure defined in claim 3 wherein the first and second
protrusions partially circumscribe the rivet, each of the
protrusions having terminal ends, said ends lying on an imaginary
line extending through the midpoint of the rivet.
6. The end closure defined in claim 2 wherein the first protrusion
lies substantially within the inner arcuate opening.
7. The end closure defined in claim 3 wherein the first and second
protrusions have equal heights of approximately 0.010 inches.
8. The end closure defined in claim 3 wherein the first and second
protrusions are separated by a substantially flat arcuate area of
the end panel.
9. The end closure defined in claim 3 in which the first and second
protrusions have generally flat outer top surfaces; and in which
said protrusions are free of connecting member therebetween.
10. The end closure defined in claim 3 wherein the second
protrusion has an arcuate length in the range of from 140.degree.
to 180.degree..
11. The end closure defined in claim 1 wherein the end closure is
formed of sheet aluminum and the central panel has a thickness of
approximately 0.007 inches.
12. The end closure defined in claim 1 wherein the first protrusion
has a height of approximately 0.010 inches.
13. The end closure defined in claim 1 wherein the first protrusion
has an arcuate length in the range of from 140.degree. to
180.degree..
14. The end closure defined in claim 1 wherein the first protrusion
lies a distance of approximately 0.20 inches from the rivet
measured between a center of the rivet and a top center of the
protrusion.
15. An easy open end closure for a container comprising: a central
panel having a tear panel defined by a score line wherein said tear
panel is to be at least partially separated from the central panel
to form an opening in said end closure; a rivet disposed on the
central panel; a pull tab hingedly secured to the rivet, said pull
tab having a nose at one end overlying the tear panel and a lift
end on an opposing end; and first and second crescent-shaped
protrusions formed in the central panel between the rivet and lift
end of the tab, said protrusions being concentric to each other and
partially circumscribe the pull tab rivet, said first and second
protrusions lying a distance from the rivet measured between a
center of the rivet and a top center of said protrusions of
approximately 0.20 inches and 0.25 inches, respectively.
16. The end closure defined in claim 15 wherein the first and
second protrusions partially circumscribe the rivet, each of the
protrusions having terminal ends, said ends lying on an imaginary
line extending through the midpoint of the rivet.
17. The end closure defined in claim 15 wherein each of the
protrusions have an arcuate length in the range of from 140.degree.
to 180.degree..
18. The end closure defined in claim 15 wherein each of the
protrusions have a height of 0.010 inches.
19. The end closure defined in claim 15 wherein the lift end of the
pull tab is formed with an outer opening to facilitate lifting of
the tab to fracture the score line with the nose of the tab, and
has an inner arcuate opening in which the rivet is located, said
inner and outer openings being separated by a cross member; and in
which the first protrusion lies substantially within the inner
opening and the second protrusion lies substantially under the
cross member.
20. The end closure defined in claim 15 wherein the first and
second protrusions are separated by a substantially flat arcuate
area of the end panel.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The invention relates to containers and pull tab openers
therefore. In particular, the invention relates to a pull tab
opener formed with one or more protrusions in the central panel
portion of the end closure approximate the rivet which reduce the
force required to lift up the back end of the tab for subsequent
breakage of the frangible panel from the end closure.
[0003] 2. Background Information
[0004] Millions of aluminum containers are produced each year,
usually for storing beverages. These containers have a pull tab for
separating a tear panel from the central panel of the end closure
to provide access to the contents of the container. These pull tabs
are attached to the central panels of the end closures by rivets
which are usually formed integral with the end closure. At one side
of the rivet opposite the outer end of the pull tab, is a scored
opening which is a push-in closure which seals the can and
withstands the internal pressure. The push-in closure or tear panel
is opened by lifting the outer end of the tab and pulling upward so
as to pivot the tab about the rivet. This tends to deform the
central panel of the end closure with the nose of the pull tab
breaking the frangible panel away from the central panel. Free lift
is referred to in the container art as the force required to lift
up the back of the tab until the tab nose begins to press down on
the frangible panel. This free lift is an ergonomic feature to
allow one to get the end of ones finger under the tab end for
leverage for lifting the tab and breaking the frangible panel.
Experience shows that this free lift is not as easy as desired in
the container industry, and that numerous attempts have been made
to reduce this free lift force without weakening the end closure
and components thereof. Furthermore, the tabs must sit tight to the
lids during can manufacturing to prevent interference with the
canning equipment and must stay properly aligned for subsequent
breakage of the frangible panel.
[0005] The ability to lift up the rear of the tab with less force
is a long time goal of the can industry. With up to 90 PSI inside
some container cans and the varying thin walls, the container is
very optimized. Numerous end closure modifications have been made
for accomplishing this function with modified and articulate tabs.
Examples of these prior art container end closures with pull tabs
which attempt to reduce the free lift are shown in U.S. Pat. Nos.
6,050,440, 6,234,336, 6,405,889, 6,575,325, and 6,889,862. Although
some of the can end closures of these prior art patents may be
satisfactory in reducing the free lift, the present invention is
believed to provide for an enhanced container end closure which
reduces the free lift force in a simple and effective manner
without materially changing the usual construction of the end
closure, and which avoids any adverse effect during can end
manufacture and subsequent attachment of the end closure to a
filled container.
BRIEF SUMMARY OF THE INVENTION
[0006] One aspect of the present invention is to provide a
container end closure primarily for beverage containers, in which
one or two C-shaped or crescent-shaped protrusions are formed in
the central panel of the end closure located closely adjacent about
the rear of the rivet, which protrusions will lessen the free lift
forces required to lift the rear end of the tab, enabling the tab
end to more easily be raised up and then pivoted about the rivet,
whereby the nose of the tab engages the frangible panel.
[0007] A further aspect of the present invention is to arrange the
crescent-shaped protrusions concentrically with respect to each
other and concentrically about the rivet, with each of the
protrusions having an arcuate length of approximately 180.degree.,
and in which the ends of the protrusions lie on an imaginary line
extending through the center of the tab rivet.
[0008] A still further feature of the present invention is to form
the crescent-shaped protrusions whereby the top center of the first
protrusion is approximately 0.20 inches from the center of the
rivet with the top center of the second protrusion lying
approximately 0.25 inches from the center of the rivet, which
distances are closer than the heretofore prior art protrusions and
indentations to facilitate the pulling up of the rivet from the
central panel to lessen the free lift forces and allow the rear of
the tab to be more easily raised up prior to the nose of the rivet
engaging the frangible panel.
[0009] A further feature of the present invention is to provide the
crescent-shaped protrusions with a height of approximately 0.010
inches when the thickness of the end panel metal, when formed of
aluminum, is approximately 0.007 inches.
[0010] A further feature of the invention is that the location of a
first and/or second protrusion is either within an opening of the
pull tab or beneath the pull tab to prevent interference with the
can manufacturing equipment and to permit the tab to lay relatively
flat against the end panel.
[0011] These features and advantages are obtained by the easy
opening end closure of the present invention, the general nature of
which may be stated as comprising: a central panel having a product
side and a public side and a tear panel defined by a score line
wherein said tear panel is to be at least partially separated from
the central panel to form an opening in said end closure; a rivet
disposed on the central panel; a pull tab hingedly secured to the
rivet, said pull tab having a nose at one end overlying the tear
panel and a lift end on an opposing end, at least one opening
formed in the opposing end of the pull tab; and a first
crescent-shaped protrusion formed in the central panel proximate
the rivet and disposed under either the lift end of the tab or
within the opening formed therein.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0012] Preferred embodiments of the invention, illustrative of the
best modes in which Applicant contemplates applying the principles,
are set forth in the following description and are shown in the
drawings and are particularly and distinctly pointed out and set
forth in the appended claims.
[0013] FIG. 1 is a top perspective view of the container end
closure with the pull tab secured thereon.
[0014] FIG. 2 is an exploded perspective view of FIG. 1 showing the
pull tab removed from the end panel.
[0015] FIG. 3 is an enlarged fragmentary top perspective view of
the end panel with the pull tab removed.
[0016] FIG. 4 is an enlarged top plan view of the end panel and
pull tab as shown in FIG. 1.
[0017] FIG. 5 is a sectional view taken on line 5-5, FIG. 4.
[0018] FIG. 5A is a greatly enlarged fragmentary view of the
encircled portion of FIG. 5.
[0019] FIG. 6 is a top perspective view of a second embodiment of
the container end closure.
[0020] FIG. 7 is an exploded perspective view of FIG. 6 with the
pull tab removed from the end panel.
[0021] FIG. 8 is an enlarged fragmentary top perspective view of
the second embodiment of FIG. 6 with the pull tab removed from the
end panel.
[0022] FIG. 9 is an enlarged top plan view of the end panel and
pull tab as shown in FIG. 6.
[0023] FIG. 10 is a sectional view taken on line 10-10, FIG. 9.
[0024] FIG. 10A is a greatly enlarged fragmentary view of the
encircled portion of FIG. 10.
[0025] FIG. 11 is a top plan view of the first embodiment of FIGS.
1-5 with the pull tab shown in dot dashed lines on the end
panel.
[0026] FIG. 12 is a top plan view of the second embodiment of FIGS.
6-10 with the pull tab shown in dot dashed lines on the end
panel.
[0027] Similar numbers refer to similar parts throughout the
drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0028] A first embodiment of the improved container end closure of
the present invention is indicated generally at 1, and is shown in
FIGS. 1-7 and 11. End closure 1 includes a central panel 3 having a
generally circular shape which includes a circumferentially
extending raised side wall 5 having an edge 7 for attaching end
closure 1 to a suitable cylindrical container (not shown) in a
manner well-known in the art.
[0029] In a preferred embodiment, end closure 1 will be formed of
aluminum with central panel 3 having a thickness of approximately
0.007 inches. A usual tear panel 9 is formed in central panel 3 and
defined by a frangible score line 11. Tear panel 9 includes a usual
curved D-shaped protrusion 13 having an inner curved portion 15
which closely aligns with the curved outer end 17 of tab nose 19 of
a usual pull tab, indicated generally at 21. Tab 21 is of a usual
construction well-known in the beverage can art, having nose 17 and
a rear curved lift end 23. Lift end 23 is grasped by a user which
positions their fingers under the end and partially into an
adjacent circular opening 25. The opposite end of the pull tab
includes nose 19 which is used to drive the tear panel 9 downwardly
when the pull tab lift end 23 is pulled upwardly and hingedly
pivots tab 21 about a pull tab rivet 29.
[0030] Rivet 29 is formed integrally in central panel 3 and is
attached to tab 21 by usual metal staking operation as it extends
through a circular hole 31 formed in a forward end of tab 21. Hole
31 is formed in an arcuate-shaped hinge portion 33 which is
partially circumscribed by an arcuate-shaped cutout 35 formed in
tab 21. Furthermore, arcuate cutout 35 is separated from tab
opening 25 by a solid material cross member 37 of pull tab 21. This
pull tab attachment construction is well-known in the container end
closure art and thus is not described in further detail.
[0031] In accordance with the main feature of the present
invention, a generally C-shaped or crescent-shaped protrusion or
depression, hereinafter referred to as protrusion 41, is formed in
central panel 3, and in particular in the oval-shaped recessed
portion 43 of central panel 3 in which the pull tab tear panel,
score line and other components of the easy opening can end tab are
located.
[0032] Protrusion 41 preferably has an arcuate length in the range
of from 140.degree. to 180.degree. and partially circumscribes
rivet 29. Protrusion 41 preferably has an arcuate length of
180.degree.. The ends of protrusion 41 as shown in FIG. 11, lie on
an imaginary line 57 which extends through midpoint 55 of rivet 29.
In the preferred embodiment, protrusion 41 has a height 45 as shown
in FIG. 5A which is approximately 0.010 inches when the thickness
of central panel 3 is approximately 0.007 inches. Furthermore, in
accordance with one of the unique features of the present
invention, the top center midpoint of protrusion 41 lies a distance
indicated at D1, from the top center midpoint 55 of rivet 29,
approximately 0.20 inches. It has been found that locating
protrusion 41 closely adjacent and rearward of rivet 29 with
respect to tab nose 19 this distance D1 provides the desired
results, that is, a lowering of the lift force required to lift
rivet end 23 upwardly from its at rest position to begin the
initial upward movement of rivet 29 closely followed by the
downward movement of tab nose 19 to fracture score line 11.
[0033] A modified enclosure is indicated generally at 51, and is
shown in particular in FIGS. 6-10 and 12. Enclosure 51 is similar
in many respects to that of end closure 1, and thus is not
described in further detail except for the addition of a second
protrusion 53. Protrusion 53 has a similar C-shape or
crescent-shape configuration as protrusion 41 and is located
concentrically with respect to protrusion 41 as shown in FIG. 8.
Protrusion 53 also extends throughout an arc of 1800 and the ends
thereof lie on the same imaginary line 57 as do the ends of
protrusion 41 as best shown in FIG. 12. As shown in FIG. 10,
protrusion 53 has a height 55 which preferably is the same as
height 45 of protrusion 41, that is, 0.010 inches when central
panel 3 has a thickness of approximately 0.007 inches. Furthermore,
in accordance with the invention, the top center midpoint of
protrusion 53 is located a distance D2, approximately 0.25 inches
from the top midpoint of rivet 29, as shown in FIG. 10A.
[0034] In accordance with still another feature of the present
invention, inner protrusion 41 lies completely within arcuate
cutout 35 of tab 21, as shown in FIGS. 4 and 9, with outer
protrusion 53 lying beneath the solid material cross member 37 of
pull tab 21 as shown in FIGS. 9 and 12. This prevents either of the
protrusions from coming into contact with the various tab-staking
equipment and transfer mechanisms used when forming end closures 1
and 51, and the subsequent equipment used for seaming the end
closures onto a filled container. It also enables the pull tab to
remain relatively flat against the central panel as is required for
use with existing can manufacturing equipment.
[0035] It has been found that the location of protrusion 41 and the
pair of protrusions 41 and 53 at the relatively close locations
rearwardly of tab 29, that is, a distance of approximately 0.20
inches and 0.25 inches respectively, and their concealment and
protection within arcuate cutout 35 and beneath tab cross member
37, provides for reduction in the free lift force and prevents the
protrusions from hampering the use of existing can-making
equipment, enabling the tab to remain in its designed flat
condition within recess 43 of the end closure. Thus, protrusion 41
and the pair of protrusions 41 and 53, enables the rivet to lift
upwardly more easily thereby lessening the free lift force on tab
end 23, allowing the rear of the tab to be more easily raised up
followed by the subsequent engagement of the nose end of the tab
against the tear panel than believed heretofore possible with
existing pull tabs having various types of projections and
protrusions formed in the end panel adjacent the rear of the
rivet.
[0036] Furthermore, as shown in the drawings, protrusions 41 and 53
have substantially flat top outer surfaces and are separated by a
substantially flat arcuate surface portion 59 of central panel 3.
Also, protrusions 41 and 53 are formed independently on central
panel 3 and are free of any connecting members or portions
therebetween, except for arcuate portion 59.
[0037] In the foregoing description, certain terms have been used
for brevity, clearness, and understanding. No unnecessary
limitations are to be implied therefrom beyond the requirement of
the prior art because such terms are used for descriptive purposes
and are intended to be broadly construed.
[0038] Moreover, the description and illustration of the invention
is an example and the invention is not limited to the exact details
shown or described.
* * * * *