U.S. patent application number 10/494642 was filed with the patent office on 2005-04-21 for easy opening closure, container provided with such closure, and apparatus for producing such closure.
Invention is credited to Bolink, Jan Johan, Emmerzaal, Ad, Leboucher, Fabrice.
Application Number | 20050082291 10/494642 |
Document ID | / |
Family ID | 8181192 |
Filed Date | 2005-04-21 |
United States Patent
Application |
20050082291 |
Kind Code |
A1 |
Emmerzaal, Ad ; et
al. |
April 21, 2005 |
Easy opening closure, container provided with such closure, and
apparatus for producing such closure
Abstract
The invention relates to an easy opening closure, comprising a
closure having a folding rim and a circumferential score line
having a score residual (t) the thickness of the closure in the
score line, enclosing a removable central closure part; and a tab
connected to the central closure part, which score line has a pop
zone in which the tap pops a section of the central closure along
the score line and the pop zone comprising a pop ignition zone
adjacent to the tab, in clock-wise and anti-clock-wise direction
subsequent tear zones in which using the tab the central closure
part is torn off from the closure along the score line and
eventually looses from the closure, wherein the tear zones comprise
each a tear ignition zone adjacent the respective pop zone, and
wherein the score residual (t) the tear ignition zones is reduced
relative to the score residual in the pop ignition zone, to a
container, provided with such easy opening closure and to an
apparatus for producing the same.
Inventors: |
Emmerzaal, Ad; (Deventer,
NL) ; Leboucher, Fabrice; (Anger, FR) ;
Bolink, Jan Johan; (Holten, NL) |
Correspondence
Address: |
WEBB ZIESENHEIM LOGSDON ORKIN & HANSON, P.C.
700 KOPPERS BUILDING
436 SEVENTH AVENUE
PITTSBURGH
PA
15219
US
|
Family ID: |
8181192 |
Appl. No.: |
10/494642 |
Filed: |
October 29, 2004 |
PCT Filed: |
October 9, 2002 |
PCT NO: |
PCT/EP02/11341 |
Current U.S.
Class: |
220/270 ;
220/276 |
Current CPC
Class: |
B65D 17/404 20180101;
B21D 51/383 20130101 |
Class at
Publication: |
220/270 ;
220/276 |
International
Class: |
B65D 017/34; B65D
017/40 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 6, 2001 |
EP |
01204232.1 |
Claims
1-12. (canceled)
13. An easy opening closure comprising a closure having a folding
rim and a circumferential score line having a score residual (t)
over the thickness of the closure in the score line, enclosing a
removable central closure part; and a tab connected to the central
closure part, which score line has a pop zone in which the tab pops
a section of the central closure along the score line and the pop
zone comprises a pop ignition zone adjacent to the tab, in
clock-wise and anti-clock-wise direction subsequent tear zones in
which using the tab the central closure part is torn off from the
closure along the score line and eventually looses from the
closure, wherein the tear zones each comprise a tear ignition zone
adjacent the respective pop zone, and wherein the score residual
(t) in the tear ignition zones is reduced relative to the score
residual in the pop ignition zone.
14. The easy opening closure as claimed in claim 13, wherein the
reduction in score residual (t) is maximum at least at the
transition between the pop zone and the adjacent tear ignition
zone.
15. The easy opening closure as claimed in claim 13, wherein the
reduction in score residual (t) decreases gradually from the
transition.
16. The easy opening closure as claimed in claim 13, wherein the
score residual (t) is reduced in a part of the pop zone adjacent to
the tear ignition zone.
17. The easy opening closure as claimed in claim 13, wherein the
reduction in score residual (t) is maximum 25 .mu.m.
18. The easy opening closure as claimed in claim 13, wherein the
maximum tear force is reduced from 1N (0.2 lbs).
19. The easy opening closure as claimed in claim 13, wherein the
reduction in score residual (t) is at least partly formed by a
score in the surface of the public side of the closure.
20. The easy opening closure as claimed in claim 13, wherein the
reduction in score residual (t) is at least partly formed by a
score in the surface of the product side of the closure.
21. The easy opening closure as claimed in claim 13, wherein the
tear zones meet in a hinge zone having a score residual (t) at
least equal to the score residual (t) of the pop ignition
zones.
22. A container, provided with the easy opening closure of claim
13.
23. An apparatus for producing an easy opening closure, comprising
a tool for forming a score in a surface of the closure, which has a
larger thickness in a tool section for forming the reduction in the
score residual.
24. The apparatus as claimed in claim 23, wherein the tool is a
lower anvil for forming a score in the surface of the product side
of the closure.
25. The easy opening closure of claim 13, wherein the reduction in
score residual (t) is in the range of 5-15 .mu.m.
26. The easy opening closure of claim 13, wherein the reduction in
score residual (t) is in the range of 7-8 .mu.m.
27. The easy opening closure as claimed in claim 14, wherein the
reduction in score residual (t) decreases gradually from the
transition.
28. The easy opening closure as claimed in claim 14, wherein the
score residual (t) is reduced in a part of the pop zone adjacent to
the tear ignition zone.
29. The easy opening closure as claimed in claim 15, wherein the
score residual (t) is reduced in a part of the pop zone adjacent to
the tear ignition zone.
30. The easy opening closure as claimed in claim 14, wherein the
reduction in score residual (t) is maximum 25 .mu.m.
31. The easy opening closure as claimed in claim 14, wherein the
maximum tear force is reduced from 1N (0.2 lbs).
32. The easy opening closure as claimed in claim 15, wherein the
maximum tear force is reduced from 1N (0.2 lbs).
Description
[0001] The present invention relates to an easy opening closure, to
a container provided with an easy opening closure, and to an
apparatus for producing such an easy opening closure.
[0002] An easy opening closure is a metal closure in which an
opening may be formed by using one or more fingers and without the
requirement for using tools. An easy opening closure comprises a
closure having a folding rim to be connected to an open end
container, and a circumferential score line provided in the closure
and enclosing a removable central closure part. This central
closure part is provided with a tab which is connected using a
rivet to the central closure part. This tab is used for providing
an opening in the easy opening closure by popping, tearing off and
subsequently loosing the central closure part along the score line
from the remaining part of the closure.
[0003] In the first part of the manual opening operation a finger
or nail is inserted between the central closure part and the free
end of the tab, whereafter that end of the tab is lifted. This
lifting movement results in a popping of a section of the central
closure as the other lever end of the tab pushes that section
inwardly and thereby breaks that section loose of the central
closure along the score line and folds that section into the
internal of the container provided with the closure. The popping
starts in the pop ignition zone which is adjacent or below the pop
end of the tab which is remote of the free end of the tab. During
lifting of the tab free end the pop end folds the section inwardly.
This lifting stops when the free end of the tab extends upwardly
from the closure (see FIG. 2). At the end of the popping operation
the central closure part is broken loose from the remainder of the
closure over the pop zone of the score line. At this place between
the scored and intact score line are the transitions between the
pop zone and the adjacent tear ignition zones. The latter are part
of the tear zones.
[0004] In the second part of the opening operation this upwardly
extending free end of the tab is gripped by one or more fingers and
the other part of the central closure is torn loose along the score
line. During this tearing operation the score opens simultaneously
in a clock-wise and anti-clock-wise direction of the score
line.
[0005] The final part of the opening procedure is the tearing off
the central closure at the diametral position to the pop ignition
zone.
[0006] The tab popping of the closure takes place in the pop zone.
The tearing in the clock-wise and anti-clock-wise direction results
in the tear zones. The tearing loose of the central closure part
from the remainder of the closure takes place in the so called
hinge zone.
[0007] In general, a metal easy opening closure has a thickness of
about 0.17 to 0.30 mm. A more specific value of this thickness is
dependent on the type of metal of the closure, such as aluminum and
tin plate. In the score line the thickness over the closure score,
the so called score residual is generally in the range of 50-90
.mu.m again dependent on the type of metal used and the content of
(pressure in) the container. The score residual is conventionally
transversally measured in the score line. In a practical embodiment
the score residual resides between score lines formed in both
surfaces of the closure. If these score lines are not aligned, then
the score residual is measured as the shortest distance between the
two score lines. In addition, both sides of the easy opening
closure is provided with a lacquer having a thickness of about 0.01
mm. The easy opening closures may be produced at high speed up to
400-500 closures per minute.
[0008] The first lift and popping of the easy opening closure using
the tab generally requires a popping force. For a tin plate closure
of 73 mm diameter this popping force is of about 15-25 N. The
tearing off in the tear ignition zones over the clock-wise and
anti-clock-wise directions by tearing the tab requires initially a
maximum tear force of 30-60 N. When the tearing progresses along
the score line the tear force gradually decreases. The total
loosing of the central part of the closure requires some force.
[0009] The dimensions of the score residual in the pop ignition
zone of the easy opening closure are selected such that it is
abuse-proof to an undesired popping of the closure by the tab when
on the pop end of the tab a force is affected, such as by end wall
stored closures in which orientation an endwall may press on the
pop part of the tab. Furthermore, a container provided with an easy
opening closure may comprise a pressurized (carbonated) beverage
and therefore the easy opening closure as a whole should be able to
withstand a burstpressure of about 3-5 bar.
[0010] The present invention has for its object to provide an easy
opening closure which possesses an improved handling in that the
opening procedure requires less tear force, in particular a smaller
initial tear force.
[0011] This is obtained with an easy opening closure according to
the invention having a curl rim and a circumferential score line
having a score residual (t) over the thickness of the closure in
the score line, enclosing a removable central closure part; and a
tab connected to the central closure part, which score line has a
pop zone in which the tab pops a section of the central closure
along the score line and the pop zone comprises a pop ignition zone
adjacent to the tab, in clock-wise and anti-clock-wise direction
subsequent tear zones in which using the tab the central closure
part is teared off from the closure along the score line and
eventually looses from the closure, wherein the tear zones comprise
each a tear ignition zone adjacent the respective pop zone, and
wherein the score residual in the tear ignition zones is reduced
relative to the score residual in the pop ignition zone.
[0012] The invention is based on the insight that by reducing the
score residual in the tear ignition zone the initial and highest
tear force is reduced and the easy opening closure still meets the
requirements for burst pressure and is still abuse-proof.
[0013] The reduction in score residual is maximum at least in that
part of the tear ignition zone, which is adjacent to the respective
pop zone. For reasons that after popping and at the start of the
tearing operation, scoring starts here at the highest tear force.
Over the length of the tear ignition zone the score residual may be
reduced to a maximum level (that is to a smallest thickness) or may
gradually increase from a maximum reduced plateau level, that is
the reduction will gradually decrease.
[0014] The end of the pop zone and the start of the tear ignition
zone is dependent on the design of the easy opening closure and on
the manner in which the popping operation has been carried out.
When the popping operation has not been carried out to its full
extent and subsequently the tearing operation is started a high
tear force may be appreciated during the scoring of the score line
in the pop zone. Therefore, it is preferred that the score residual
is reduced in a part of the pop zone adjacent to the tear ignition
zone.
[0015] The effect of the invention is appreciated when the
reduction in score residual is maximum at the beginning of the tear
ignition zones. This reduction in the score residual may have the
form of an abrupt step or may gradually decrease over a part of the
pop zone, but reaches the maximum at least at the transition
between the pop zone and the adjacent tear ignition zone. This
reduction in score residual (t) is relative to the score residual
in the pop ignition zone, which is generally having a higher or
highest score residual in order to impart the easy opening closure
with abuse-proof properties.
[0016] The reduction in score residual which results in an
appreciation of a lower tear force is generally such that the
maximum tear force is reduced as from 1N (0.2 lbs), such as 1-15N
(0.2-3.3 lbs), reductions in maximum tear force of 1-10N (0.2-2.2
lbs) or 1-8N (0.2-1.8 lbs) are feasible within the ghist of the
present invention, all in comparison with an easy opening closure
which is not provided with the inventive reduction of score
residual in at least the tear ignition zones.
[0017] The score residual may be reduced over the score line length
in the tear zones, but it may be sufficient that it is only reduced
in at least the first part of the tear zone. This reduction is
relative to the mid part of the score line in the pop zone because
at the interface between the pop zone and tear zone the residual
may already be reduced such that at the start of the tear zone the
residual score is maximum reduced, the sight where the highest tear
force is initially required.
[0018] The reduction in score residual is generally maximum 25
.mu.m. Practically the reduction is in the range of 5-15 .mu.m.
Good reductions in initial tear force are obtainable at 6-9 .mu.m,
such as 7-8 .mu.m. This in comparison to the score residual in at
least the pop ignition zone where the score residual is generally
in the range of 60-90 .mu.m, such as 65-80 .mu.m, 70-85 .mu.m and
70-80 .mu.m.
[0019] In a preferred embodiment the score residual in the pop
ignition zone is higher than in the remainder of the pop zone.
Accordingly, the pop force for the initial popping the central
closure part is increased but to a level which is still below the
maximum initial tear force.
[0020] The formation of the reduced score residual is critical in
view of the burst pressure and the requirement for abuse-proof. In
a preferred embodiment the reduction in score residual is at least
partly formed by a score in the surface of the public side of the
closure. A variation in the reduced score residual in at least the
tear ignition zones is minimal if the reduction in score residual
is at least partly formed between a score in the public facing
surface and a score in the surface of the product side of the
closure (see FIG. 3B).
[0021] An other aspect of the invention relates to a container
which is provided with an easy opening closure of the invention. In
this container its end opening is connected to the rim of the easy
opening closure by a folding operation of the closure rim and the
container rim.
[0022] Finally, the invention relates in an other aspect to an
apparatus for producing such easy opening closure. This apparatus
is provided with particular means for forming the reduced score
residual. To that extent the apparatus is characterized in that it
comprises a tool for forming a score in a surface of the closure
which has a larger thickness in a tool section for forming the
reduction in the score residual. In a preferred embodiment the
apparatus comprises a lower anvil and the score is formed in the
surface of the product side of the closure.
[0023] Mentioned and other advantages and characteristic features
of the easy opening closure, a container provided therewith and an
apparatus for producing the closure are illustrated in the
following figures illustrating embodiments of the invention
although the invention is not considered to be restricted thereto.
In the figures:
[0024] FIG. 1 shows a top view of an easy opening closure according
to the invention;
[0025] FIG. 2 illustrates the popping operation of the closure;
[0026] FIGS. 3A and 3B show two embodiments of the apparatus used
for producing the opening closure; and
[0027] FIG. 4 shows the score residual of the easy opening closure
of the invention over the clock-wise or anti-clock-wise
direction.
[0028] FIG. 1 shows an easy opening closure 1. The closure 1
comprises a curl rim 2 which extends over the circumference of the
closure 1. Radially inwardly of the rim 2 is provided a score line
3 which encloses a removable central closure part 4. In cross
section the central part 4 has a substantially terrass form. The
central part 4 is provided with a tab 5 which is connected by a
rivet 6 to the central part 4. The tab 5 has a first free end 7
with an opening 8 and a pop end 9.
[0029] The score line 3 comprises several zones. A pop ignition
zone 10 where due to a levering action of the tab 5 the pop end 9
of tab 5 pops the central part 4 inwardly by scoring alone the
score line 3. Due to an undesired action on the pop end 9 by a load
an undesired interaction of the pop end with the score results in
an abusive opening of the score. This pop ignition zone 10 lies
within the lines 11 and 12 and forms part of the pop zone which
lies between the lines 13 and 14. These lines 13 and 14 are defined
by a cord 38 extending between the points 39 and 40 where the
scoring of the score line 3 stopped at the end of the popping
operation by lifting the tab 5 (see FIG. 2). The pop zone is
followed by a tear ignition zone 15 in clock-wise direction and
tear zone 16 in anti-clock-wise direction and is limited by the
lines 14 and 17 and the lines 13 and 18 respectively. In the tear
ignition zones 15 and 16 highest tear forces are encountered. The
length of the tear ignition zones 15 and 16 corresponds to a length
over which the tear forces reduces to 60-90%, such as 70 or 80% of
the maximum value for the tear ignition. The tear ignition zones 15
and 16 are followed by the other parts of the tear zone 19 and 20
and meet in an optional hinge zone 21.
[0030] FIG. 2 shows the end of the pop procedure in which the tab
popped the score line 3 thereby forming an opening 22. The tab 5 is
extending upwardly with its end 7. Over the pop zone between the
lines 13 and 14 the central closure part 4 is loose from the
remainder of the closure 1.
[0031] FIG. 4 shows the reduction of the score residual t over the
length of the score line 3. The reduction of the score residual in
the pop ignition zone 10 is nil. In the tear ignition zone, in
particular at the transition 24, the reduction of the score
residual is maximum and amounts 8 .mu.m in this embodiment of the
closure and forms a plateau 23. In both circumferential directions
the score residual t gradually decreases to the plateau 23 in the
pop zones (between the respective lines 12 and 14, and 11 and 13)
and in the tear ignition zones 15 and 16 gradually increases (curve
A). In an other embodiment (for instance when the content of the
container is not pressurized) the reduction of the score residual
may stay substantially constant in the tear zones 19 and 20 but
decrease gradually towards a hinge zone 21 where the scored central
point is broken off from the closure (curve B).
[0032] In the pop ignition zone 10 the residual may be increased to
about 70 .mu.m to make the closure more abuse-proof. In the hinge
zone 21 the residual may also be increased (for instance to about
100-150 .mu.m in order to make the closure more injury-proof.
[0033] Finally, FIG. 3 shows an apparatus 26 for producing an easy
opening closure of the invention. The apparatus comprises a score
die 27 and lower anvil 28. The lower anvil 28 has a flat anvil
surface 29. The upper anvil 27 has an sharp end 30 for making the
score line 3 in the closure 1. The score residual (t) shown in the
tear ignition zone 25.
[0034] FIG. 3B shows an other apparatus 31 for producing an easy
opening closure 1 according to the invention. This apparatus 31
comprises a score die 27 with the sharp end 30, but comprises in
addition a lower anvil 32 which has a rounded anvil surface 33.
[0035] The closure 1 produced in the apparatus 26 has a public
facing surface 34 in which the score line 3 is produced and a
product facing surface 35 which is flat in the region of the score
3.
[0036] The closure 1 produced with the apparatus 31 of FIG. 3B has
a score 3 in the public facing surface 34 and a score 36 in the
product facing surface 37. In the apparatus 31 the scores may be
formed in one step or in two consecutive steps.
[0037] Using both apparatuses 26 and 31 of the invention at high
speed production closures of the invention may be produced at
standard tolerances.
* * * * *