U.S. patent application number 13/478523 was filed with the patent office on 2012-09-13 for small diameter can end with large opening.
This patent application is currently assigned to Crown Cork & Seal Technologies Corporation. Invention is credited to Brian Fields.
Application Number | 20120228296 13/478523 |
Document ID | / |
Family ID | 10843585 |
Filed Date | 2012-09-13 |
United States Patent
Application |
20120228296 |
Kind Code |
A1 |
Fields; Brian |
September 13, 2012 |
SMALL DIAMETER CAN END WITH LARGE OPENING
Abstract
A can end having a small diameter centre panel and an opening of
particular dimensions to improve the pourability and drinkability
characteristics of the opening, compared to can ends having
conventional openings.
Inventors: |
Fields; Brian; (Lemont,
IL) |
Assignee: |
Crown Cork & Seal Technologies
Corporation
Alsip
IL
|
Family ID: |
10843585 |
Appl. No.: |
13/478523 |
Filed: |
May 23, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12564739 |
Sep 22, 2009 |
8196767 |
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13478523 |
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09857145 |
May 31, 2001 |
7594585 |
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PCT/GB99/03899 |
Nov 24, 1999 |
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12564739 |
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Current U.S.
Class: |
220/269 |
Current CPC
Class: |
B65D 2517/0062 20130101;
B65D 2517/5097 20130101; B65D 2517/0014 20130101; Y10S 220/906
20130101; B65D 17/4012 20180101; B65D 2517/0071 20130101 |
Class at
Publication: |
220/269 |
International
Class: |
B65D 17/34 20060101
B65D017/34 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 4, 1998 |
GB |
9826602.6 |
Claims
1. An easy open can end having improved flow characteristics, the
easy open can end comprising: a circular center panel having a
rupturable score line that defines a non-removable tear panel, the
center panel having a diameter that is less than 1.835 inches (46.6
mm); and a non-detachable tab coupled to the center panel, the tab
having a nose portion and a rear portion such that in use, the rear
portion of the tab is lifted to cause the nose portion of the tab
to press down on the tear panel, thereby rupturing the score line
and swinging the tear panel out of the plane of the center panel to
create an elliptical opening, the opening having a major axis and a
minor axis, the minor axis located on a diameter of the center
panel and the major axis located perpendicular to said diameter,
wherein dimensions of the tear panel along the major axis and the
minor axis are such that the can end exhibits a higher first peak
of flow rate compared with a first peak of flow rate of an end
having an aspect ratio of 1.1 and an opening area of 0.450 square
inches.
2. An easy open can end according to claim 1, further comprising a
side wall that is inclined at an angle of between 20.degree. and
60.degree. to the plane of the center panel.
3. An easy open can end according to claim 1, wherein the tear
panel further comprises a bead which substantially follows the
periphery of the score and the nose portion of the tab.
4. An easy open end according to claim 3, wherein the bead on the
tear panel is closed.
5. An easy open end according to claim 1, wherein the dimensions of
the tear panel along the major axis and the minor axis are such
that the can end exhibits a higher first peak of flow rate compared
with a first peak of flow rate of an end having an aspect ratio of
1.47 and an opening area of 0.596 square inches.
Description
[0001] This is a continuation of U.S. patent application Ser. No.
12/564,739, filed Sep. 22, 2009, which is a continuation of U.S.
patent application Ser. No. 09/857,145, filed May 31, 2001, now
issued as U.S. Pat. No. 7,594,585, which is the National Stage of
International Application No. PCT/GB99/03899, filed Nov. 24, 1999,
which claims priority to GB Application Number 9826602.6 filed Dec.
4, 1998, the disclosures of which are incorporated herein by
reference in their entirety.
BACKGROUND
[0002] The present invention relates to can ends having a
non-removable tear panel which defines a large opening for improved
pour characteristics, so called large opening ends (LOE). In
particular, the invention relates to the shape of such large
openings in can ends having a reduced diameter centre panel.
[0003] Typically, aluminium or steel cans filled with beer, soft
drinks or the like are provided with easy open, stay on tab type
ends having a non-removable tear panel which is torn and swung down
into the can to provide an opening through which the contents of
the can may be dispensed. The opening provided in conventional cans
is generally small and as a consequence it is not possible to pour
the contents from the can in a smooth manner because the liquid
tends to be dispensed in small spurts or glugs. This is
particularly difficult where the contents are being drunk directly
from the can as the glugs mean that the liquid has to be
sipped.
[0004] Can ends having larger openings have been proposed, for
example in U.S. Pat. No. 5,711,448, in order to improve pourability
and drinkability. This improved performance is usually obtained by
providing openings of larger area than the conventional openings
discussed above. The pour characteristics of these large openings
allow the contents of the can to be dispensed at higher flow rates
than conventional openings, with fewer spurts or glugs. This allows
the contents of a can to be drunk directly from the can, in a more
natural manner.
[0005] Can ends are made in a variety of sizes from 202 to 211
(using conventional can makers' terminology). However, there is
continual pressure to reduce the size of can ends. Recently, 206
ends were conventionally used for all beverage cans and these size
ends are still used on the majority of beer cans in Europe.
However, on cans for soft drinks, 202 ends are now the industry
standard in both the US and Europe and there is industry pressure
to reduce the remaining 206 ends to 202 ends. Thus, cans are being
produced with successively smaller diameter ends in order to
provide cost savings through lightweighting.
[0006] Furthermore, it has been proposed to reduce the diameter of
the centre panel of the can end whilst retaining the nominal can
end diameter, as discussed in WO 96/37414. Such can ends have an
outer circumferential "hook" which is separated from a smaller
diameter centre panel by an inclined side wall. The side wall is
inclined at an angle of between 20.degree. to 60.degree. to the
plane of the centre panel.
[0007] As centre panels become smaller (either through reducing the
size of the can end or through the use of inclined side walls) it
becomes more difficult to provide an opening having the area
considered necessary to obtain improved pouring and drinking
performance, due to the reduced distance between the rivet and the
side wall of the end panel.
SUMMARY
[0008] The aim of the present invention is to provide an easy open,
stay on tab can end, having an opening with improved pourability
and drinkability characteristics but suitable for use on ends
having a smaller diameter centre panel than conventional, standard
202 ends. Hence, the present invention is suitable for use on 202
ends having sloping side walls as previously discussed and on
smaller diameter standard ends, such as 200 and below.
[0009] Accordingly, the present invention provides an easy open can
end comprising a circular centre panel with a rupturable score line
therein, the score line defining the periphery of a non-removable
tear panel, a non-detachable tab having a nose portion and a rear
portion, and a connection between the tab and the centre panel
which acts as a pivot about which the tab can be rotated out of the
plane of the centre panel, such that in use, the rear portion of
the tab is lifted to cause the nose portion of the tab to press
down on the tear panel, thereby rupturing the score line and
swinging the tear panel out of the plane of the centre panel to
create an opening, the opening having a major axis and a minor
axis, the minor axis located on a diameter of the centre panel and
the major axis located perpendicular to said diameter,
characterised in that the diameter of the centre panel is less than
1.835 inches (46.6 mm) and the opening has an area of less than 0.5
square inches (323 mm.sup.2) and an aspect ratio (major axis:minor
axis) of between 1.3 and 1.7.
[0010] All centre panel dimensions quoted in this specification
relate to the dimensions of the die used to produce the centre
panel. Thus the centre panel diameter quoted is the internal panel
diameter of the centre panel.
[0011] The inventors have discovered that the pourability and
drinkability characteristics of the opening in a can end are
affected more by the aspect ratio and orientation of the opening
than by its area. Hence, the opening in a can end having a smaller
diameter centre panel can be designed with greatly improved
pourability characteristics without increasing the area of the
opening above the threshold value of 0.5 square inches stipulated
in the cited prior art.
[0012] The criteria for assessing a good LOE is that the flow rate
from the can opening, with a "vent" space above the surface of the
liquid, should exceed that which can be swallowed by the average
consumer. This allows the average consumer to drink the contents of
the can in a natural manner, without any spurts or glugs. When the
flow rate from the opening is too low, the consumer will tend to
tilt the can further, to increase the flow rate, and this cuts off
the air space above the surface of the liquid, causing glugging.
Alternatively, in order to obtain smooth pouring, the consumer will
have to sip the contents of the can due to the low flow rate.
[0013] Considering a can end having an opening in which the minor
axis of the opening lies along a diameter of the end and its major
axis lies perpendicular to such diameter, significant improvements
in pourability may be obtained by providing a tear panel (and hence
an opening once the tear panel is torn and swung back into the can)
with an aspect ratio of between 1.3 and 1.7 (major axis : minor
axis), preferably with an aspect ratio of about 1.5.
[0014] When the aspect ratio is below 1.3, the opening in the can
tends towards a circular shape as in conventional ends. The flow
rate from such openings tends to be low and the consumer then tilts
the can further than is desirable to obtain a higher flow rate,
resulting in unsatisfactory glugging. When the aspect ratio is
above 1.7, the opening in the can tends towards an elongated shape
which means that even slight variations in the tilt of the can
results in large variations in the flow rate. Hence, at aspect
ratios above 1.7, the flow rate from the opening is too sensitive
to variations in the tilt of the can. This means that too much
precision is required by the consumer to obtain the required flow
rate, without blocking the air passage above the surface of the
liquid.
[0015] Preferably the opening is elliptical, as this is the most
suitable shape to provide the required aspect ratio whilst ensuring
that the pivotal movement of the tab is sufficient to fracture the
score line along its entire length. However, enhancements to the
tearing of the score line may be achieved by using an enhanced tab
design or by providing a bead configuration which strengthens the
centre panel around the score line and tab.
[0016] Preferably, the can end also comprises a bead on the tear
panel which substantially follows the outline of the score line but
which is shaped around the front of the nose of the tab. This bead
configuration helps to strengthen the tear panel and prevent it
from being distorted as it is opened, thereby assisting rupture of
the score line along its entire length.
BRIEF DESCRIPTION OF THE FIGURES
[0017] The present invention will now be described, by way of
example only, with reference to the accompanying drawings, in
which:
[0018] FIG. 1 shows a plan view of one embodiment of a can end
according to the invention.
[0019] FIG. 2 shows a side section through the can end shown in
FIG. 1.
[0020] FIG. 3 shows pour rate data for various 202 ends with
different aperture sizes (showing 202 Standard, 202 LOE and 202 LOE
with reduced diameter centre panel).
DETAILED DESCRIPTION
[0021] FIGS. 1 and 2 show a can end 1 according to one embodiment
of the invention. The can end 1 has a sloping side wall 2 and a
centre panel 3 of reduced diameter, D (as shown in FIG. 2). The
centre panel 3 is marked with a rupturable score line 10 which
defines a tear panel 11. The score line 10 has an open
configuration and the unmarked area between the start and finish of
the score line 10 defines a hinge 12. The can end 1 also comprises
a tab 20 having a nose portion 21 at one end, which extends over
the edge of the tear panel 11. The other end of the tab 20 is
provided with a rear, lifting portion. The tab 20 is connected to
the centre panel 3 by a rivet 25 positioned adjacent to the score
line 10, on the other side of the score line to the nose of the tab
21. The tear panel 11 is provided with a closed, raised bead 15
which follows the periphery of the tear panel 11 and the nose of
the tab 21.
[0022] To open the can, the rear portion of the tab 20 is raised
and the tab 20 pivots out of the plane of the centre panel 3 about
the rivet 25, pressing the nose of the tab 21 against the tear
panel 11 adjacent to the score line 10. This movement initially
ruptures the portion of the score line 10 which extends below the
tab 20 and allows any gas which has built up within the can to vent
(the "pop"). As the tab 20 is raised further, rupture of the score
continues around the periphery of the score line 10 and the tear
panel 11 swings out of the plane of the centre panel 3, into the
body of the can about the hinge portion 12, defining an opening in
the can end 1. The bead 15 on the tear panel 11 provides stiffness
and prevents the tear panel 11 from distorting as the end 1 is
being opened. This in turn assists the propagation of the rupture
of the score line 15 around the periphery of the tear panel 11 to
the hinge portion 12. The resultant opening has a minor axis, which
lies on a diameter X-X of the end 1 and a major axis Y-Y, which
lies perpendicular to this diameter, at the point where the opening
has its maximum dimension along this axis.
[0023] As shown in FIG. 1, when the centre panel 3 is of reduced
diameter, the minor axis of the opening is restricted by the
reduced distance between the rivet 25 and the start of the side
wall 30. This means that it is difficult, to obtain an opening
having an area of greater than 0.5 square inches (323 mm.sup.2), as
stipulated in the prior art as the size of opening required to
obtain improved pouring performance. However, the applicants have
found that improved pouring performance can be obtained from an
opening having an area less than 0.5 square inches (323 mm.sup.2),
provided the aspect ratio of the opening (major axis:minor axis) is
between 1.3 and 1.7.
[0024] The applicants have carried out a number of tests to measure
the pour rates of cans fitted with ends having various size
apertures and centre panels. In these tests, the test can was
opened and then rotated from a vertical to horizontal orientation
in three seconds. The contents of the can were allowed to flow
freely from the can and the flow rate measured at predetermined,
constant time intervals.
[0025] FIG. 3 shows the results of these tests for three 202 ends
with differently configured centre panels and aperture size: A
conventional 202 LOE, A; a 202 LOE according to the invention with
reduced diameter centre panel, B and a conventional 202 end with
standard size opening, C. As shown in FIG. 3, the conventional 202
end, C, with an opening of area 0.450 square inches (290 mm.sup.2)
and an aspect ratio of 1.1, exhibited fluctuations in flow rate
(glugging) and took the longest time to reach its maximum flow
rate. The 202 LOE, A, with an opening of area 0.596 square inches
(384.5 mm.sup.2) and an aspect ratio of 1.47, showed far fewer flow
rate fluctuations and reached a significantly higher maximum flow
rate in the least time. However a 202 end according to the
invention, B, having a reduced diameter centre panel and an opening
of area 0.487 square inches (314 mm.sup.2) and an aspect ratio of
about 1.5, was found to exhibit significantly improved pouring
characteristics (with fewer flow rate fluctuations and improved
flow rate versus time profile) compared to the standard 202 end.
The flow rate versus time profile for the 202 LOE according to the
invention, B, shows a performance comparable to that of the known
202 LOE, A.
* * * * *