U.S. patent application number 10/533760 was filed with the patent office on 2006-06-15 for integrally moulded closure system.
This patent application is currently assigned to Portola Packaging Limited. Invention is credited to Stephen Glover, Gerry Mavin, Timothy Graham Stephenson.
Application Number | 20060124575 10/533760 |
Document ID | / |
Family ID | 9947149 |
Filed Date | 2006-06-15 |
United States Patent
Application |
20060124575 |
Kind Code |
A1 |
Mavin; Gerry ; et
al. |
June 15, 2006 |
Integrally moulded closure system
Abstract
There is described a closure system comprising a cap (14), a
neck (12) and tamper evident means (16, 78) integrally moulded in a
unitary structure. The structure allows the application of the
tamper evident means prevents the cap from being removed from the
neck while the tamper evident means remains intact.
Inventors: |
Mavin; Gerry;
(Northhumberland, GB) ; Stephenson; Timothy Graham;
(Northumerland, GB) ; Glover; Stephen; (South
Yorkshire, GB) |
Correspondence
Address: |
DORSEY & WHITNEY LLP
555 CALIFORNIA STREET, SUITE 1000
SUITE 1000
SAN FRANCISCO
CA
94104
US
|
Assignee: |
Portola Packaging Limited
Carriage Drive White Rose Way
Doncaster
GB
DN4 5NT
|
Family ID: |
9947149 |
Appl. No.: |
10/533760 |
Filed: |
October 31, 2003 |
PCT Filed: |
October 31, 2003 |
PCT NO: |
PCT/GB03/04710 |
371 Date: |
May 4, 2005 |
Current U.S.
Class: |
215/252 ;
215/258; 215/344 |
Current CPC
Class: |
B65D 5/746 20130101;
B65D 41/3433 20130101 |
Class at
Publication: |
215/252 ;
215/258; 215/344 |
International
Class: |
B65D 51/00 20060101
B65D051/00; B65D 49/12 20060101 B65D049/12; B65D 53/00 20060101
B65D053/00 |
Claims
1. A closure system comprising a cap, a neck and tamper evident
means integrally moulded in a unitary structure, the structure
allowing the application of the cap to the neck whereupon the
tamper evident means prevents the cap from being removed from the
neck while the tamper evident means remains intact.
2. A closure system according to claim 1, wherein an intermediate
member is joined to the neck at a first frangible connection and
joined to the cap at a second frangible connection, the first
frangible connection being adapted to break upon application of the
cap to the neck whereupon the intermediate member co-operates with
the neck and the cap to form said tamper evident means.
3. A closure system according to claim 2, wherein said intermediate
member comprises an annular band adapted to pass over the neck upon
application of the cap to the neck and a transition member joined
to the annular band, the transition member being adapted to
co-operate with the neck to resist the subsequent removal of the
annular band from the neck.
4. A closure system according to claim 3, wherein the transition
member is hinged to the annular band.
5. A closure system according to claim 3, wherein the annular band
is joined to the transition member by a web, the web forming a
hinge permitting the transition member to flex with respect to the
annular band.
6. A closure system according to claim 5, wherein the web
constitutes a region of reduced thickness.
7. A closure system according to claim 3, wherein the neck is
provided with a locking wall, the transition member being adapted
to engage with the locking wall to resist subsequent removal of the
annular band upon application of the cap to the neck.
8. A closure system according to claim 3, wherein the transition
member is joined to the neck at said first frangible connection,
said first frangible connection being adapted to break upon
application of the cap to the neck only after the act of applying
the cap to the neck causes the transition member to fold inwardly
of the annular band.
9. A closure system according to claim 3, wherein upon application
of the cap to the neck the transition member hinges with respect to
the annular band, folding inwardly and into engagement with a
locking wall provided on the neck.
10. A closure system according to claim 3, wherein the annular band
is joined to the cap at said second frangible connection, said
second frangible connection being adapted to break upon the
attempted removal of the cap from the neck.
11. A closure system according to claim 2, wherein said first and
second frangible connections lie within respective parallel
planes.
12. A closure system according to claim 2, wherein one or both of
said first and second frangible connections are formed as a line of
weakness defined by a region of reduced thickness.
13. A closure system according to claim 8, wherein the transition
member is tapered in the direction of said first frangible
connection so that the transition member is joined to the neck in a
region of reduced thickness.
14. A closure system according to claim 2, wherein one or both of
said first and second frangible connections are formed as a
plurality of frangible tabs.
15. A closure system according to claim 14, wherein said plurality
of frangible tabs are circumferentially spaced with each tab being
separated from an adjacent tab on either side by a pair of slits,
each slit communicating at opposite ends thereof with a respective
pair of apertures of increased cross-section.
16. A closure system according to claim 15 wherein a respective
pair of apertures of increased cross-section constitutes an area of
weakness disposed on either side of each of the tabs.
17. A closure system according to claim 3, wherein the transition
member extends from the neck to the annular band within a generally
frustoconical surface.
18. A closure system according to claim 3, wherein the transition
member extends from the neck to the annular band in a direction
which is inclined radially outwardly at an angle of between 22 and
32 to the axis of the closure system.
19. A closure system according to claim 3, wherein the transition
member comprises a plurality of circumferentially spaced transition
elements, the transition elements having a first circumferential
dimension adjacent the annular band and a second circumferential
dimension adjacent the neck, said first circumferential dimension
being greater than said second circumferential dimension.
20. A closure system according to claim 19, wherein the transition
elements are separated by a plurality of apertures, the apertures
being arranged in groups on circumferentially opposite sides of the
transition member.
21. A closure system according to claim 3, wherein the transition
member comprises one or more pleats or folds.
22. A closure system according to claim, wherein the transition
member comprises a plurality of circumferentially spaced transition
elements separated by areas of reduced thickness.
23. A closure system in accordance with claim 1, wherein the cap is
provided with engagement means for repeated and releasable
engagement with complimentary engagement means provided on the
neck.
24. A closure system according to claim 23 wherein the pair of
complimentary engagement means comprise a pair of helical thread
configurations.
25. A closure system according to claim 24 wherein the thread
configuration provided on the neck is a female thread
configuration.
26. A closure system according to claim 24, wherein the pair of
thread configurations are adapted so as to permit the application
of the cap to the neck by means of an axially applied force
whereupon the threads on the cap slide over those provided on the
neck and then interengage.
27. A closure system according to claim 26, wherein the threads on
the cap are orientated with respect to those on the neck in such a
way that upon axial application of the cap to the neck the
respective thread configurations are placed in optimal
thread-engagement.
28. A closure system according to claim 1, wherein the cap is
provided with an annular plug for receipt within a bore of the
neck.
29. A closure system in accordance with claim 1, wherein the
closure system comprises a fitment for attachment to a carton or
other container.
30. A closure system according to claim 1, wherein the closure
system is integrally moulded with a container, the neck forming a
neck of the container.
31. A method of closing a container in a tamper evident manner
comprising the steps of moulding a neck of the container in one
piece with a cap and tamper evident means to form a unitary
structure and applying the cap to the neck in such a way that the
cap is prevented from being removed from the neck while the tamper
evident means remains intact.
32. An integrally moulded closure system comprising a cap applied
to a neck, the closure system including tamper evident means
integrally moulded with the cap and neck, the tamper evident means
preventing removal of the cap from the neck while the tamper
evident means remains intact.
Description
[0001] The present invention relates to an integrally moulded
closure system comprising a cap and neck and having tamper evident
means such that, having applied the cap to the neck, the cap is
prevented from being removed from the neck prior to the removal of
the tamper evident means.
[0002] In WO 99/37547 there is described a one piece fitment having
a reclosure cap. The fitment comprises a spout which converges
upwardly and has a cylindrical external locking bead. Above the
spout is an outward slanted tear band and above the tear band is a
reclosure cap comprising a top, a depending skirt formed with
internal interrupted beads and a plug. The tear band is connected
to the spout and cap by thin horizontal tear lines. A pull tab
extends outwardly or downwardly with respect to the tear band so
that a consumer may conveniently grip the pull tab and pull it
circumferentially around the fitment to separate the tear band from
both the spout and the cap. The cap is dimensioned so that the
skirt fits over the outside of the spout with the internal beads
detachably locking under the locking bead. The plug seals against
the inside of the spout to prevent spillage.
[0003] Thus it is known to provide a closure system comprising a
cap and neck which are integrally moulded in a unitary structure.
It is also known for such a structure to comprise tamper evident
means since, before its removal, the tear band and reclosure cap
function as a tamper evident closure for the spout. However, what
is not known and what has previously not been provided is an
integrally moulded closure system comprising a cap and neck and
which incorporates tamper evident means in which the cap may be
applied to the neck prior to the removal of the tamper evident
means. Similarly, there has been no disclosure of a closure system
comprising a cap applied to a neck in which tamper evident means
prevents the removal of the cap from the neck prior to the removal
of the tamper evident means, the cap, neck and tamper evident means
having been integrally moulded in a unitary structure.
[0004] According to a first aspect of the present invention there
is provided a closure system comprising a cap, a neck and tamper
evident means integrally moulded in a unitary structure, the
structure allowing the application of the cap to the neck whereupon
the tamper evident means prevents the cap from being removed from
the neck while the tamper evident means remains intact.
[0005] Advantageously an intermediate member is joined to the neck
at a first frangible connection and joined to the cap at a second
frangible connection, the first frangible connection being adapted
to break upon application of the cap to the neck whereupon the
intermediate member co-operates with the neck and the cap to form
said tamper evident means. Preferably the intermediate member
comprises an annular band adapted to pass over the neck upon
application of the cap to the neck and a transition member joined
to the annular band, the transition member being adapted to
co-operate with the neck to resist the subsequent removal of the
annular band from the neck. Preferably the transition member is
hinged to the annular band. For example, the annular band may be
joined to the transition member by a web, the web forming a hinge
permitting the transition member to flex with respect to the
annular band. Advantageously the web may constitute a region of
reduced thickness. Alternatively, the web may be of substantially
the same thickness as the transition member but include one or more
score lines to permit the transition member to flex with respect to
the annular band.
[0006] Advantageously the neck is provided with a locking wall, the
transition member being adapted to engage with the locking wall to
resist subsequent removal of the annular band upon application of
the cap to the neck. Preferably the transition member is joined to
the neck at said first frangible connection, said first frangible
connection being adapted to break upon application of the cap to
the neck only after the act of applying the cap to the neck causes
the transition member to fold inwardly of the annular band.
[0007] Advantageously, upon application of the cap to the neck the
transition member hinges with respect to the annular band, folding
inwardly and into engagement with a locking wall provided on the
neck.
[0008] Advantageously the annular band may be joined to the cap at
said second frangible connection, said second frangible connection
being adapted to break upon the attempted removal of the cap from
the neck.
[0009] Advantageously the first and second frangible connections
may lie within respective parallel planes.
[0010] Advantageously one or both of the first and second frangible
connections may be formed as a line of weakness defined by a region
of reduced thickness. In one preferred embodiment the transition
member is tapered in the direction of the first frangible
connection so that the transition member is joined to the neck in a
region of reduced thickness.
[0011] Advantageously one or both of the first and second frangible
connections may be formed as a plurality of frangible tabs. The
plurality of frangible tabs may be circumferentially spaced with
each tab being separated from an adjacent tab on either side by a
pair of slits, each slit communicating at opposite ends thereof
with a respective pair of apertures of increased cross-section. In
this way a respective pair of apertures of increased cross-section
may constitute an area of weakness disposed on either side of each
of the tabs.
[0012] Advantageously, the transition member may extend from the
neck to the annular band within a generally frustoconical
surface.
[0013] Advantageously the transition member extends from the neck
to the annular band in a direction which is inclined radially
outwardly at an angle of between 220 and 320 to the axis of the
closure system.
[0014] Advantageously the transition member may comprise a
plurality of circumferentially spaced transition elements, the
transition elements having a first circumferential dimension
adjacent the annular band and a second circumferential dimension
adjacent the neck, the first circumferential dimension being
greater than the second circumferential dimension. Preferably, the
transition elements are separated by a plurality of apertures, the
apertures being arranged in groups on circumferentially opposite
sides of the transition member.
[0015] Alternatively, the transition member may comprise one or
more pleats or folds. In another arrangement the transition member
may comprise a plurality of circumferentially spaced transition
elements separated by areas of weakness or reduced thickness.
[0016] Advantageously the cap may be provided with engagement means
for a repeated and releasable engagement with complimentary
engagement means provided on the neck. Preferably the pair of
complimentary engagement means may comprise a pair of helical
thread configurations. Under such circumstances, the said
configuration provided on the neck is preferably a female thread
configuration.
[0017] Advantageously the pair of thread configurations are adapted
so as to permit the application of the cap to the neck by means of
an axially applied force whereupon the threads on the cap slide
over those provided on the neck and then interengage. Preferably
the treads on the cap are orientated with respect to those on the
neck in such a way that upon axial application of the cap to the
neck the respective thread configurations are placed in optimal
thread engagement.
[0018] Advantageously the cap may be provided with an annular plug
for receipt within a bore of the neck.
[0019] Advantageously the closure system comprises a fitment for
attachment to a carton or other container. Alternatively, the
closure system may be integrally moulded with a container, the neck
forming a neck of the container.
[0020] According to a second aspect of the present invention there
is provided a method of closing a container in a tamper evident
manner comprising the steps of moulding a neck of the container in
one piece with a cap and tamper evident means to form a unitary
structure and applying the cap to the neck in such a way that the
cap is prevented from being removed from the neck while the tamper
evident means remains intact.
[0021] According to a third aspect of the present invention there
is provided an integrally moulded closure system comprising a cap
applied to a neck, the closure system including tamper evident
means integrally moulded with the cap and neck, the tamper evident
means preventing removal of the cap from the neck while the tamper
evident means remains intact.
[0022] The present invention will now be described by way of
example with reference to the accompanying drawings in which:
[0023] FIG. 1 is an elevational side view of a closure system
embodying the present invention;
[0024] FIG. 2 is a cross-sectional view of the closure system of
FIG. 1;
[0025] FIG. 3 is a perspective view of the closure system of FIG.
1;
[0026] FIG. 4 is an elevational side view of the closure system of
FIG. 1 once the cap portion has been applied to the neck
portion;
[0027] FIG. 5 is a cross-sectional view of the closure system once
the cap portion has been applied to the neck portion;
[0028] FIG. 6 is a perspective view of the closure system of FIG. 1
once the cap portion has been applied to the neck portion; and
[0029] FIG. 7 is a cross-sectional view of the closure system
taking along lines VII-VII of FIG. 1.
[0030] As shown in FIG. 1, a closure system embodying the present
invention may take the form of a fitment 10. The fitment 10
comprises a neck portion 12, a cap portion 14 and, between the two,
a transition member 16 which joins the neck portion 12 to the cap
portion 14.
[0031] Looking firstly at the neck portion 12, the neck portion
comprises an apertured flange 18 having substantially smooth and
planer upper and lower surfaces 20 and 22 respectively. Surrounding
the aperture, a cylindrical wall 24 projects upwardly from the
upper flange surface 20 to form the neck. Adjacent to the flange
18, the external surface of the cylindrical wall 24 is smooth
before merging with a radially outwardly projecting locking wall 26
to define a shoulder. At an end of the locking wall 26 remote from
the cylindrical wall 24, the locking wall 26 in turn merges with an
upwardly and radially inwardly inclined surface 30 which, with the
radially outwardly projecting locking wall 26, defines an annular
locking bead 32. Above the annular locking bead 32, the upwardly
and radially inwardly inclined surface 30 merges with a neck
stretch portion 34 of slightly increased diameter compared to the
cylindrical wall 24 in which is provided engagement means with
which to engage complimentary engagement means provided on the cap
portion 14. In the example shown, the engagement means provided on
the neck stretch portion 34 takes the form of an equi-spaced,
multi-lead female helical thread configuration 36 which includes
four threads or leads 36a, 36b, 36c and 36d. It will be apparent
however, that the engagement means may take a number of different
forms and, in particular, need not be limited to four threads or
leads but may comprise one, two or three threads as appropriate.
The engagement means may also comprise five or more threads if so
desired. Generally speaking however, it is preferable for the
configuration to comprise a plurality of threads.
[0032] In the illustrated embodiment, each thread 36a, 36b, 36c and
36d extends about 1200 around the circumference of the neck stretch
portion 34. Once again however, it will be understood that threads
of a lesser or greater extent may also be employed. For example,
each thread 36a, 36b, 36c, 36d may extend within a range from
90.degree. to more than 360.degree.. Preferably the helical thread
configuration 36 has a fine thread density to limit the vertical
float of the cap portion 14 on the neck portion 12. Thus the thread
density preferably lies within a range of between 6 and 12 threads
per linear inch. Most preferably of all, is a thread density of
approximately 8% threads per linear inch.
[0033] Above the helical threads 36, the neck stretch portion 34
merges with a second upwardly and radially inwardly inclined
surface 38 which in turn merges with a further vertical neck
stretch portion 40 before terminating in an annular rim 42.
[0034] At a radially inner edge, the annular rim 42 merges with a
downwardly and radially inwardly inclined surface 44. This
downwardly and radially inwardly inclined surface 44 in turn merges
with a substantially smooth inner surface 46 of the cylindrical
wall 24. The substantially smooth inner surface 46 flares radially
outwardly adjacent the flange 18 to define a downwardly and
radially outwardly inclined surface 48. Adjacent to the transition
between the substantially smooth inner surface 46 and the
downwardly and radially outwardly inclined surface 48, the
substantially smooth inner surface 46 is provided with a plurality
of circumferentially spaced, radially inwardly projecting lugs
50.
[0035] Turning to the cap portion 14, the cap portion comprises a
circular top 52 having an under surface 54. The circular top 52
merges at a radially outer edge with a downwardly and radially
outwardly inclined surface 56 which in turn merges with a depending
annular side wall 58 to form a downwardly extending upper skirt
portion 60. The depending annular side wall 58 is provided on an
inner surface 62 with complimentary engagement means for repeated
and releasable engagement with the engagement means provided on the
neck portion 12. As before, these engagement means may take many
forms but, in the example shown, comprise an equi-spaced,
multi-lead, male helical thread configuration 64 having four
threads or leads 64a, 64b, 64c and 64d and a thread density of
approximately 8% threads per linear inch. In the embodiment shown
each thread extends approximately 120.degree. around the inner
surface 62 of the depending annular side wall 58. However, it is to
be understood that this thread length may be increased or decreased
if desired. For example, each thread may extend in a range from
90.degree. to more than 360.degree.. Likewise, the thread density
is not intended to be limited to being about 81/2 threads per
linear inch but, nevertheless, preferable lies within the range
from about 6 to about 12 threads per linear inch. Preferably, the
female thread configuration 36 on the neck portion 12 and the male
thread configuration 64 on the cap portion 14 each have at least
two threads and a thread density of at least 6 threads per linear
inch. As shown, the male threads 64a, 64b, 64c and 64d provided on
the cap portion 14 may be interrupted at intervals along their
length.
[0036] In order to facilitate the axial application of the cap
portion 14 to the neck portion 12 when an axially downward force is
applied to the cap portion in a direction to urge the cap portion
into engagement with the neck portion, the threads of the male
helical thread configuration 64 may be provided with an appropriate
cross-sectional shape. For example, the threads may be formed with
an asymmetric cross-section or else may be made less
pronounced.
[0037] In the illustrated embodiment, the two thread configurations
36 and 64 each comprise multiple turns of thread. As a result a
vertical line drawn across the thread configuration 36 on the neck
portion 12 intersects two or three turns of thread depending upon
the location of the line around the circumference of the neck
stretch portion 34. At the same time a vertical line drawn across
the thread configuration 64 on the cap portion 14 intersects one or
two turns of thread depending upon the location of the line around
the circumference of the depending annular side wall 58. This
ensures that when the cap portion 14 is applied to the neck portion
12 there will be multiple turns of thread engagement. Of course,
the total cumulative thread engagement is subject to variation and,
depending upon the linear thread density, may be as little as one
turn of thread engagement or more than three turns of thread
engagement.
[0038] In addition to the male helical thread configuration 64, the
interior of the cap portion 14 is provided with an annular plug 66
which depends from the under surface 54 of the circular top 52 and
which is spaced radially inwardly of the depending annular side
wall 58. The annular plug 66 is defined by respective radially
inner and outer walls 68 and 70, the radially outer plug wall 70
merging at an end remote from the circular top 52 with a generally
downward and radially inwardly directed surface 72. This downwardly
and radially inwardly directed surface 72 intersects the radially
inner plug wall 68 and together serves to provide the annular plug
66 with a bevelled radially outer surface and a tapering
cross-section. This tapering cross-section is further accentuated
by the fact that, whereas the radially outer plug wall extends in a
direction substantially perpendicular to the plane of the under
surface 54, the radially inner plug wall 68 extends from the under
surface 54 in a direction which is both downwardly and radially
outwardly.
[0039] By contrast, on the exterior of the cap portion 14, the
depending annular side wall 58 is provided on its outer surface
with a plurality of circumferentially spaced, vertical extending
ribs 74 which serve as knurls to facilitate the gripping of the cap
portion 14 by a user. As is common with a number of caps, a small
downwardly directed dimple 76 is formed in the centre of the
circular top 52 so that any flash left after the cap portion has
been moulded does not project above a plane defined by the upper
surface of the circular top 52.
[0040] In addition to the foregoing features, the cap portion 14 is
provided with an annular band 78 which is formed as an extension of
the depending annular side wall 58 at a position remote from the
circular top 52 and beneath the male helical thread configuration
64. To this end the exterior surface of the annular band 78
occupies an extension of the same cylindrical surface as that
defined by the exterior surface of the depending annular side wall
58. By contrast, the inner surface 62 of the depending annular side
wall 58 merges, via a short downwardly and radially outwardly
inclined surface 80, with an inner band surface 82 of slightly
greater inner diameter. At an end remote from the depending annular
side wall 58, and therefore at an end remote from the circular top
52, the inner band surface 82 merges with the exterior band surface
via a radially outwardly directed rim 84. Both the inner and
exterior surfaces of the annular band 78 are formed free of
projections so as to be substantially smooth.
[0041] The annular band 78 is delimited from the depending annular
side wall 58 by a plurality of arcuate slits 86 which are
circumferentially spaced at intervals around the cap portion 14 and
in the same horizontal plane. As a result the spacings between the
arcuate slits 86 define a plurality of circumferentially spaced
tabs 88 by which the annular band 78 is connected to the depending
annular side wall 58. At opposite ends of each of the arcuate slits
86, the slits open out into apertures 90 of increased
cross-section, thereby weakening the area on either side of each of
the tabs 88.
[0042] As shown in FIG. 1, the cap portion 14 is initially joined
to the neck portion 12 by means of transition member 16. In the
example illustrated, the transition member 16 comprises a
downwardly and radially inwardly inclined frustoconical wall which
is provided with a plurality of trapezium-shaped apertures 92 which
serve to define therebetween a similar number of transition
elements 94. Each transition element 94 lies within a frustoconical
surface and has an upper circumferential dimension adjacent the
annular band 78 which is greater than a lower circumferential
dimension adjacent the neck portion 12. Furthermore, each
transition element 94 is joined to the annular band 78 by a thin,
upwardly and radially outwardly inclined web 96 which merges with
the annular band 78 at the intersection of the inner surface 82 and
the radially outwardly directed rim 84. At the opposite end, the
inner surface of each transition element 94 is bevelled with the
result that each transition element tapers to an edge 98 and it is
at this edge 98 that the transition element 94 merges with the neck
portion 12 at the intersection of the annular rim 42 and the
downwardly and radially inwardly inclined surface 44.
[0043] The closure system herein described may be moulded in one
piece with the neck portion 12 integrally formed and joined with
the transition member 16 and with the transition member integrally
formed and joined with the cap portion 14. However, in order to
assemble the closure system an axially downwardly directed force is
applied to the cap portion in a direction towards the neck portion
12. With the closure system in the orientation shown in FIG. 1, it
will be understood that as the cap portion 14 moves downwardly
under the action of the applied force so the plurality of
transition elements 94 begin to hinge about their respective
tapered edges 98. At the same time the transition elements 94 also
flex with respect to the annular band 78, the flexure being
accommodated by the initially upwardly and radially outwardly
inclined webs 96. As a result, as the cap portion 14 is urged
downwardly towards the neck portion 12, the transition elements 94
fold upwards into the annular band 78 with the consequence that, as
the radially outwardly directed rim 84 passes over the further
vertical neck stretch portion 40 followed by the neck stretch
portion 34, the transition elements 94 take up an orientation in
which they extend from the annular rim 42 of the neck portion to
the annular band 78 in a downward and radially outward
direction.
[0044] With the cap portion 14 pressed down onto the neck portion
12 to the extent permitted by the hinging action of the transition
elements 94, it will be recognised that although the annular band
78 now overlies the neck stretch portion 34, the male helical
thread configuration 64 provided on the cap portion is not yet in
engagement with the female helical thread configuration 36 provided
on the neck portion. Continued downward movement of the cap portion
14 under the action of the applied force causes the transition
elements 94 to break away from the neck portion 12 along their
respective tapering edges 98. The cap portion 14 is then free to
move downwardly onto the neck portion 12 with the transition
elements 94 still folded upwardly within the annular band 78. As
the cap portion 14 moves downwardly so the transition elements 94
ride over the neck stretch portion 34 and the female helical thread
configuration 36 until such time as the now downwardly and radially
outwardly inclined webs 96 encounter the upwardly and radially
inwardly inclined surface 30 of the cylindrical locking wall 24. At
approximately the same time the male threads of the helical thread
configuration 64 provided on the cap portion 14 encounter the
second upwardly and radially inwardly inclined surface 38 which
constitutes the transition between the neck stretch portion 34 and
the further vertical neck stretch portion 40. Meanwhile, in the
interior of the neck portion 12, the end of the annular plug 66
remote from the circular top 52 is received within the annular rim
42.
[0045] Continued downward pressure on the cap portion 14 causes the
now downwardly and radially outwardly inclined webs 96 and the
transition elements 94 to slide over the upwardly and radially
inwardly inclined surface 30 causing the transition elements to be
pressed up against the smooth inner band surface 82 and causing the
annular band 78 to flex slightly radially outwardly. However, as
the tapered edge 98 passes over the transition between the upwardly
and radially inwardly inclined surface 30 and the radially
outwardly projecting locking wall 26, so the transition elements 94
are free to flex under the restoring action of the now downwardly
and radially outwardly inclined webs 96 bringing the tapered edges
98 into confronting relationship with the locking wall 26. At the
same time, the slight radially outward flexing of the annular band
78 coincides with the slight radially outward flexing of the upper
skirt portion 60 as the male helical thread configuration 64 slides
over and into engagement with the female helical thread
configuration 36. Also at this time the annular plug 66 is received
within the bore of the neck portion 12 defined by the substantially
smooth inner surface 46. In so doing the generally downward and
radially inwardly directed surface 72 slides along the downwardly
and radially inwardly inclined surface 44 causing the annular plug
66 to flex slightly radially inwardly. Once fully received within
the neck portion 12, the restoring force inherent in the resilient
nature of the design and materials making up the annular plug 66
causes the radially outer plug wall 70 to be urged into sealing
engagement with the substantially smooth inner surface 46. Thus, in
the assembled condition, the interaction between the annular plug
66 and the substantially smooth inner surface 46 constitutes a
primary seal.
[0046] A secondary seal is provided in the assembled condition by
the receipt of the annular rim 42 within the annular recess defined
between the radially outer plug wall 70 and the downwardly and
radially outwardly inclined surface 56 of the cap portion 14. In
order to accommodate the annular rim 42 the radially outwardly
inclined surface 56 is forced to flex slightly radially outwardly
with the result that the restoring force holds the radially
outwardly inclined surface in sealing engagement with the annular
edge defined by the intersection of the annular rim 42 and the
further vertical neck stretch portion 40.
[0047] With the closure system in the assembled condition the
fitment 10 may be applied to a paperboard or other carton in the
conventional manner. In this regard it will be noted that the
flared opening to the neck portion 12 defined by the downwardly and
radially outwardly inclined surface 48 facilitates the insertion of
a spud of a manipulation tool. At the same time the provision of
the plurality of circumferentially spaced, radially inwardly
projecting lugs 50 facilitate the retention of the fitment on the
spud. Since the apertured flange 18 has substantially smooth and
planar upper and lower surfaces 20 and 22, the fitment 10 may be
bonded either to the outside or to the inside of a carton panel as
desired. However, in another arrangement, the neck portion 12 may
be provided with one or more additional projections which cooperate
with the apertured flange 18 to retain the fitment 10 in a specific
orientation with respect to the carton panel to which the fitment
is to be attached.
[0048] Once the fitment 10 has been applied to a carton, the
fitment provides that carton with a closure that can be repeatedly
opened and closed as desired and which offers excellent sealing and
re-sealing characteristics. In addition, the fitment also provides
a tamper evident capability to alert a consumer should the contents
of the carton have been compromised prior to initial opening. This
tamper evident capability is provided in the form of a tear-band
which must first be separated from the cap portion 14 before the
cap portion can be removed from the neck portion 12. If a consumer
finds that the tear-band has been separated from the cap portion 14
before the fitment 10 has first been opened by them then it is
possible that the contents of the carton may have been tampered
with or may have become adversely affected in some other way. The
tamper evident capability of the fitment functions as follows.
[0049] In the assembled condition the cap portion 14 is prevented
from being removed from the neck portion 12 in an axial direction
by the interengagement of the male and female helical thread
configurations 64 and 36 and by the engagement of the tapered edges
98 with the annular locking bead 32. In order to remove the cap
portion therefore, a user is required to rotate the cap portion 14
with respect to the neck portion 12. This causes the threads of the
male thread configuration 36 to rise up the grooves of the female
thread configuration 36 bringing the tapered edges 98 more firmly
into engagement with the locking wall 26. Continued upward movement
of the cap portion 14 with respect to the neck portion 12 is
resisted by the transition elements 94 with the result that the
upward force exerted by a user in unscrewing the cap portion is
applied to the circumferentially spaced tabs 88 which serve to
connect the annular band 78 to the depending annular sidewall 58.
The provision of apertures 90 of increased cross-section on either
side of each of the tabs 88 ensures that the tabs will fracture as
a user continues to unscrew the cap portion 14 and long before any
damage is sustained to the now downwardly and radially outwardly
inclined webs 96. Once the tabs 88 have been broken the cap portion
14 may be removed and the contents dispensed from the carton. The
cap portion 14 may be reapplied and subsequently removed from the
neck portion 12 as often as it is desired.
[0050] In the example shown, once the tabs 88 have been fractured,
the tear-band (in the form of annular band 78 and transition
elements 94) remains in place on the neck portion 12 beneath the
locking wall 26. However, it will be appreciated that in order to
provide the tear-band with a drop-down capability which may more
easily alert a consumer to potential tampering, all that is
required is to elongate the portion of the cylindrical wall 24
between the apertured flange 18 and the radially outwardly
projecting locking wall 26.
[0051] It will be apparent to those skilled in the art that the
closure system of the present invention is not limited to the
embodiment described and that numerous variations are possible.
Having said, in order to facilitate the manufacturing process it
has been found advantageous to limit the extent to which the
internal diameter of the annular band 78 exceeds the internal
diameter of the substantially smooth inner surface 46.
[0052] Although the annular band 78 clearly has to pass over the
neck stretch portion 34, if the difference between these two
internal diameters becomes too large it becomes difficult to
extract that part of the mould tool responsible for the internal
surface features (the core) through the restricted opening defined
by the neck portion 12 and transition member 16. For this reason,
although it is possible to provide the neck portion 12 with a male
thread configuration with which to engage a complimentary
configuration provided on the cap portion 14, nonetheless a female
thread configuration is preferred. A female thread configuration 36
on the neck portion 12 also provides the advantage that there are
no radial protrusions which might otherwise foul the annular band
78 as the cap portion 14 is applied to the neck portion 12.
[0053] In order to facilitate the extraction of the core it has
also been found preferable for the transition elements 94 to be
inclined radially outwardly at an angle of between 22.degree. and
32.degree. to the vertical, and most preferably, at an angle of
27.degree. to the vertical. At the same time, in the specific
embodiment shown, the vertical distance between the radially
outwardly directed rim 84 and the annular rim 42 is preferably 3.5
mm while the tapered edge 98 preferably has a radial dimension of
between 0.16 mm and 0.10 mm. Elsewhere along their length the
transition elements 94 preferably have a dimension at right angles
to the angle of inclination of 0.5 mm.
[0054] Whilst the trapezium-shaped apertures 92 may be arranged at
intervals around the transition member 16, for ease of moulding the
apertures are preferably arranged in groups of three on
circumferentially opposite sides of the closure system. In this way
the trapezium-shaped apertures 92 may be formed using slides that
open and close at right angles to the male and female halves of the
mould tool. In such an arrangement, each group of three
trapezium-shaped apertures 92 are preferably symmetrical about a
vertical centre line with the central trapezium-shaped aperture
having an upper circumferential dimension adjacent the annular band
78 of 2 mm and the two mutually inclined sides of the aperture
subtending an angle of 30.degree.. The trapezium-shaped apertures
on either side are preferably spaced 6.2 mm from the centre line
and arranged so as to have an upper circumferential dimension
adjacent the annular band 78 of 1 mm while the mutually inclined
sides of the apertures subtend an angle of 25.degree.. In order to
facilitate the folding upwards of the transition elements 94 into
the annular band 78 as the cap portion 14 is pushed onto the neck
portion 12, the two trapezium-shaped apertures 92 spaced on either
side of the central aperture within each group of three are
preferably not themselves symmetrical. Rather, the inclined edge of
the two side apertures closest to the central trapezium-shaped
aperture preferably subtends an angle of 20.degree. with respect to
the centre line. In this way each transition element 94 has an
upper circumferential dimension adjacent the annular band 78 which
is greater than its lower circumferential dimension adjacent the
neck portion 12.
[0055] By contrast to the transition member 16, the annular band 78
has a vertical dimension from the short downwardly and radially
outwardly inclined surface 80 to the radially outwardly directed
rim 84 of 4.55 mm with the distance from the short downwardly and
radially outwardly inclined surface 80 to the arcuate slits 86
accounting for 0.5 mm of that vertical dimension. In order to
facilitate the removal of the core and to ensure that the tabs 88
are reliably fractured upon initial unscrewing of the cap portion
14, the slits 86 preferably have a vertical dimension of 0.25 mm
and open out into apertures 90 having a vertical dimension of 0.85
mm. This leaves the annular band 78 with a vertical dimension of
3.2 mm between the apertures 90 and the radially outwardly directed
rim 84.
[0056] As with the trapezium-shaped apertures 92, the arcuate slits
86 are preferably formed using slides that open and close at right
angles to the male and female halves of the mould tool. The arcuate
slits 86 are therefore preferably formed so as to have no undercuts
in the direction of movement of the slides. This means that the
surfaces joining the circumferential outer surface of the annular
band 78 to the inner band surface 82 do not extend radially but
rather have the configuration shown in FIG. 7 in which the surfaces
on either side of one of the tabs 88 subtend an angle of
135.degree. while those at opposite ends of one of the arcuate
slits 86 subtend an angle of 92.degree.. In order to ensure that
the tabs 88 fracture reliably they are preferably circumferentially
spaced at intervals of 45.degree. and have a radial dimension of
0.25 mm. The apertures 90 on either side of each of the tabs 88 are
preferably dimensioned so that an arcuate slit 86 joining two such
apertures has a circumferential dimension of 7.0 mm.
[0057] One of the advantages of the closure assembly herein
described is that the cap portion 14 is held in fixed relationship
with the neck portion 12 prior to application of the cap portion to
the neck portion. As a result it is possible, with suitable
alignment of the thread configurations 36 and 64, to ensure that
once the cap portion 14 has been applied to the neck portion 12 the
threads are optimally engaged. This in turn means that no
subsequent tightening of the cap portion 14 is required thereby
simplifying the capping process in comparison with the processes of
the prior art. At the same time, the optimization of the thread
engagement means that the closure system may utilise the minimum
thread length commensurate with the sealing properties required,
thereby enabling savings in both cap and neck height. This in turn
translates into a saving of plastics material which bears a direct
relation to the cost of manufacture of the closure system. The
optimization of the thread engagement also serves to eliminate any
vertical float of the cap portion 14 on the neck portion 12 which
would otherwise have to be allowed for in the vertical distance
between the annular locking bead 32 and the apertured flange 18.
Because this vertical float can be eliminated, the closure system
can be designed so that the transition elements 94 engage with the
locking bead 32 almost immediately upon unscrewing of the cap
portion 14, thereby rendering the closure system more secure
against unwanted tampering as well as cheaper to manufacture.
[0058] Although the present invention has been described in
relation to a fitment for attachment to a carton, it will be
appreciated by those skilled in the art that the invention is not
so limited and that the closure assembly may be formed integrally
with a container if so desired.
* * * * *