U.S. patent application number 11/340825 was filed with the patent office on 2009-07-30 for closures and containers in combination therewith.
This patent application is currently assigned to Portola Packaging Limited. Invention is credited to Gerry Mavin, Timothy Stephenson.
Application Number | 20090188887 11/340825 |
Document ID | / |
Family ID | 9955573 |
Filed Date | 2009-07-30 |
United States Patent
Application |
20090188887 |
Kind Code |
A1 |
Mavin; Gerry ; et
al. |
July 30, 2009 |
Closures and containers in combination therewith
Abstract
There is described a closure for use with a container neck. The
closure comprises a cap and an insert. The insert is adapted to be
permanently adhered to the container neck and has a sealing
surface. The cap comprises a complimentary sealing surface for
sealable engagement with the sealing surface provided on the insert
and engagement means for releasable engagement with complimentary
engagement means provided on the container neck.
Inventors: |
Mavin; Gerry; (Ashington,
GB) ; Stephenson; Timothy; (Doncaster, GB) |
Correspondence
Address: |
JAMES P. HANRATH
191 NORTH WACKER DRIVE, SUITE 1800
CHICAGO
IL
60606
US
|
Assignee: |
Portola Packaging Limited
Doncaster
GB
|
Family ID: |
9955573 |
Appl. No.: |
11/340825 |
Filed: |
January 25, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10764434 |
Jan 23, 2004 |
|
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11340825 |
|
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Current U.S.
Class: |
215/324 ;
215/329 |
Current CPC
Class: |
B65D 2251/023 20130101;
B65D 51/20 20130101; B65D 2251/0087 20130101; B65D 2251/0015
20130101; B65D 47/103 20130101 |
Class at
Publication: |
215/324 ;
215/329 |
International
Class: |
B65D 41/00 20060101
B65D041/00; B65D 41/04 20060101 B65D041/04 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 26, 2003 |
GB |
0306972.1 |
Claims
1. A closure for use with a container neck, the closure comprising
a cap and an insert, the insert being adapted to be permanently
adhered to the container neck and having a sealing surface and the
cap comprising a complimentary sealing surface for sealable
engagement with the sealing surface provided on the insert and
engagement means for releasable engagement with complimentary
engagement means provided on the container neck.
2. A closure in accordance with claim 1 wherein the container neck
has a rim surrounding an axial bore and the insert is adapted to be
received within the bore, the insert having a flange adapted to
project outwardly from the bore to overlie the surrounding rim such
that the insert protrudes axially from the bore no more than the
thickness of the flange.
3. A closure in accordance with claim 1 wherein the container neck
has an external neck surface and the insert is shaped such that no
part of the insert overlies the external neck surface.
4. A closure in accordance with claim 1 wherein the cap comprises a
top and a depending side wall, the engagement means being provided
on an interior surface of the depending side wall.
5. A closure in accordance with claim 1 wherein the engagement
means comprise a helical thread configuration.
6. A closure in accordance with claim 1 wherein the engagement
means comprise a first formation adapted to be snapped over and
held in position by a second retaining formation provided on the
container neck.
7. A closure in accordance with claim 2 wherein the bore is
cylindrical and the flange is adapted to project radially outwardly
from the bore.
8. A closure in accordance with claim 2 wherein the external
dimension of the flange is less than that of the rim it is adapted
to overlie.
9. A closure in accordance with claim 2 wherein the flange
incorporates a pour lip.
10. A closure in accordance with claim 2 wherein the flange is
adapted to be permanently adhered to the container neck.
11. A closure in accordance with claim 2 wherein an undersurface of
the flange incorporates a recess for the receipt of a sealing
medium with which to permanently adhere the insert to the container
neck.
12. A closure in accordance with claim 1 wherein the insert is
adapted to by wholly received within the external dimensions of the
cap.
13. A closure in accordance with claim 1 wherein the cap has the
same silhouette as that of a conventional cap thereby enabling the
closure to be applied using existing capping equipment.
14. A closure in accordance with claim 1 wherein the container neck
defines a bore and the insert comprises a wall adapted to be
received within the bore, an interior surface of the wall defining
the sealing surface provided on the insert and an exterior surface
of a plug provided on the cap defining the complimentary sealing
surface provided on the cap.
15. A closure in accordance with claim 14 wherein the bore and wall
are cylindrical and the plug provided on the cap is annular.
16. A closure in accordance with claim 1 wherein the insert is
provided with a removable membrane with which to close off the
container neck.
17. A closure in accordance with claim 16 wherein the removable
membrane is at least in part defined by a frangible line of
weakness and is provided with a pull-ring with which to separate
the membrane from the remainder of the insert.
18. A closure in accordance with claim 16 wherein at least a
portion of the removable membrane is concave.
19. A closure in accordance with claim 1 wherein both the cap and
the insert comprise injection moulded plastics components.
20. A closure in combination with a container having a container
neck, the closure being in accordance with claim 1.
21. The combination of claim 20 wherein the container and container
neck are of a conventional design thereby enabling the container to
be manipulated on a production line using existing equipment.
22. A closure for use with a container neck, the container neck
having a rim surrounding an axial bore and the closure comprising a
cap and an insert, the cap having a sealing surface and the insert
being adapted to be received within the bore and permanently
adhered to the container neck and having a complimentary sealing
surface for sealable engagement with the sealing surface provided
on the cap and a flange, the flange being adapted to project
outwardly from the bore to overlie the surrounding rim such that
the insert protrudes axially from the bore no more than the
thickness of the flange.
23. A closure in accordance with claim 22 wherein the cap is
provided with engagement means for releasable engagement with
complimentary engagement means provided on the container neck.
24. A closure in accordance with claim 22 wherein the container
neck has an external neck surface and the insert is shaped such
that no part of the insert overlies the external neck surface.
25. A closure in accordance with claim 23 wherein the cap comprises
a top and a depending side wall, the engagement means being
provided on an interior surface of the depending side wall.
26. A closure in accordance with claim 23 wherein the engagement
means comprise a helical thread configuration.
27. A closure in accordance with claim 23 wherein the engagement
means comprise a first formation adapted to be snapped over and
held in position by a second retaining formation provided on the
container neck.
28. A closure in accordance with claim 22 wherein the bore is
cylindrical and the flange is adapted to project radially outwardly
from the bore.
29. A closure in accordance with claim 22 wherein the external
dimension of the flange is less than that of the rim it is adapted
to overlie.
30. A closure in accordance with claim 22 wherein the flange
incorporates a pour lip.
31. A closure in accordance with claim 22 wherein the flange is
adapted to be permanently adhered to the container neck.
32. A closure in accordance with claim 22 wherein an undersurface
of the flange incorporates a recess for the receipt of a sealing
medium with which to permanently adhere the insert to the container
neck.
33. A closure in accordance with claim 22 wherein the insert is
adapted to be wholly received within the external dimensions of the
cap.
34. A closure in accordance with claim 22 wherein the cap has the
same silhouette as that of a conventional cap thereby enabling the
closure to be applied using existing capping equipment.
35. A closure in accordance with claim 22 wherein the container
neck defines a bore and the insert comprises a wall adapted to be
received within the bore, an interior surface of the wall defining
the sealing surface provided on the insert and an exterior surface
of a plug provided on the cap defining the complimentary sealing
surface provided on the cap.
36. A closure in accordance with claim 35 wherein the bore and wall
are cylindrical and the plug provided on the cap is annular.
37. A closure in accordance with claim 22 wherein the insert is
provided with a removable membrane with which to close off the
container neck.
38. A closure in accordance with claim 37 wherein the removable
membrane is at least in part defined by a frangible line of
weakness and is provided with a pull-ring with which to separate
the membrane from the remainder of the insert.
39. A closure in accordance with claim 37 wherein at least a
portion of the removable membrane is concave.
40. A closure in accordance with claim 22 wherein both the cap and
the insert comprise injection moulded plastics components.
41. A closure in combination with a container having a container
neck, the closure being in accordance with claim 22.
42. The combination of claim 41 wherein the container and container
neck are of a conventional design thereby enabling the container to
be manipulated on a production line using existing equipment.
43. A closure for use with a container neck having an external neck
surface, the closure comprising a cap and an insert, the cap having
a sealing surface and the insert having a complimentary sealing
surface for sealable engagement with the sealing surface provided
on the cap, the insert being adapted to be permanently adhered to
the container neck and shaped such that no part of the insert
overlies the external neck surface.
44. A closure in accordance with claim 43 wherein the cap is
provided with engagement means for releasable engagement with
complimentary engagement means provided on the container neck.
45. A closure in accordance with claim 43 wherein the container
neck has a rim surrounding an axial bore and the insert is adapted
to be received within the bore, the insert having a flange adapted
to project outwardly from the bore to overlie the surrounding rim
such that the insert protrudes axially from the bore no more than
the thickness of the flange.
46. A closure in accordance with claim 44 wherein the cap comprises
a top and a depending side wall, the engagement means being
provided on an interior surface of the depending side wall.
47. A closure in accordance with claim 44 wherein the engagement
means comprise a helical thread configuration.
48. A closure in accordance with claim 44 wherein the engagement
means comprise a first formation adapted to be snapped over and
held in position by a second retaining formation provided on the
container neck.
49. A closure in accordance with claim 45 wherein the bore is
cylindrical and the flange is adapted to project radially outwardly
from the bore.
50. A closure in accordance with claim 45 wherein the external
dimension of the flange is less than that of the rim it is adapted
to overlie.
51. A closure in accordance with claim 45 wherein the flange
incorporates a pour lip.
52. A closure in accordance with claim 45 wherein the flange is
adapted to be permanently adhered to the container neck.
53. A closure in accordance with claim 45 wherein an undersurface
of the flange incorporates a recess for the receipt of a sealing
medium with which to permanently adhere the insert to the container
neck.
54. A closure in accordance with claim 43 wherein the insert is
adapted to be wholly received within the external dimensions of the
cap.
55. A closure in accordance with claim 43 wherein the cap has the
same silhouette as that of a conventional cap thereby enabling the
closure to be applied using existing capping equipment.
56. A closure in accordance with claim 43 wherein the container
neck defines a bore and the insert comprises a wall adapted to be
received within the bore, an interior surface of the wall defining
the sealing surface provided on. the insert and an exterior surface
of a plug provided on the cap defining the complimentary sealing
surface provided on the cap.
57. A closure in accordance with claim 56 wherein the bore and wall
are cylindrical and the plug provided on the cap is annular.
58. A closure in accordance with claim 43 wherein the insert is
provided with a removable membrane with which to close off the
container neck.
59. A closure in accordance with claim 58 wherein the removable
membrane is at least in part defined by a frangible line of
weakness and is provided with a pull-ring with which to separate
the membrane from the remainder of the insert.
60. A closure in accordance with claim 58 wherein at least a
portion of the removable membrane is concave.
61. A closure in accordance with claim 43 wherein both the cap and
the insert comprise injection moulded plastics components.
62. A closure in combination with a container having a container
neck, the closure being in accordance with claim 43.
63. The combination of claim 62 wherein the container and container
neck are of a conventional design thereby enabling the container to
be manipulated on a production line using existing equipment.
64. A closure in combination with a container having a container
neck defining a bore, the closure comprising a cap and an insert,
the insert being permanently adhered container neck and comprising
a wall received within the bore and the cap comprising a plug which
sealingly engages with an interior surface of said wall at a
location within the container neck.
65. The combination of claim 64 wherein, at the location of sealing
engagement, the wall of the insert is interposed between the plug
and a surface of the container neck defining the bore.
66. The combination of claim 64 wherein the plug is formed so as to
not only sealingly engage with an interior surface of the wall but
also to urge an external surface of the wall into sealing
engagement with a surface of the container neck defining the
bore.
67. The combination of claim 64 wherein the insert is formed of low
density polyethylene (LDPE) and the cap is formed of high density
polyethylene (HDPE).
68. The combination of claim 64 wherein the closure comprises a cap
and an insert, the insert being adapted to be permanently adhered
to the container neck and having a sealing surface and the cap
comprising a complimentary sealing surface for sealable engagement
with the sealing surface provided on the insert and engagement
means for releasable engagement with complimentary engagement means
provided on the container neck.
69. The combination of claim 64 wherein the closure comprises a cap
and an insert, the cap having a sealing surface and the insert
being adapted to be received within the bore and permanently
adhered to the container neck and having a complimentary sealing
surface for sealable engagement with the sealing surface provided
on the cap and a flange, the flange being adapted to project
outwardly from the bore to overlie a rim surrounding the bore such
that the insert protrudes axially from the bore no more than the
thickness of the flange.
70. The combination of claim 64 wherein the closure comprises a cap
and an insert, the cap having a sealing surface and the insert
having a complimentary sealing surface for sealable engagement with
the sealing surface provided on the cap, the insert being adapted
to be permanently adhered to the container neck and shaped such
that no part of the insert overlies an external surface of the
neck.
Description
[0001] The present invention relates to the packaging of fluids
and, in particular, to closures for containers in which the closure
is capable of providing resealable access to the contents of the
container.
[0002] In the specification which follows the problems of fluid
packaging will be discussed with particular reference to the
problems associated with the packaging of milk. However, it will be
appreciated that other potable fluids such as water and fruit
juices present similar packaging problems.
[0003] Conventionally, milk has been packaged in blow-moulded
plastics containers which are provided with resealable caps. The
resealable caps are typically formed of injection moulded plastics
material. There is however, a fundamental problem in achieving a
good seal between a blow-moulded plastics container and an
injection moulded plastics cap. This is because the tolerance of
the neck of the container may be of the order of .+-.0.3 mm whereas
the tolerance of an injection moulded item, such as the cap, is
typically .+-.0.1 mm. This means that it is inevitable that a
proportion of the caps made to a particular specification will not
seal tightly when fitted to the necks of the containers for which
they are intended. This in turn leads to production difficulties in
applying the caps to the container necks and leakage problems for
both retailers and distributors of the packaged product.
[0004] This problem is further exacerbated by the fact that the
blow-moulded plastics containers are typically manufactured at a
different location and by a different producer from the injection
moulded plastics caps. This is because, although the containers
could be supplied to the bottling plant ready made, this would
inevitably result in the need to transport large volumes. It is
therefore more usual for the blow-moulded containers to be produced
in a blow-moulding plant adjacent the dairy so that they can be
formed and filled on one continuous production line.
[0005] However, the consequence of having two parts, the container
and the cap, which must co-operate if there is to be an adequate
seal, manufactured by different parties and at different locations
means that on those occasions when the sealing characteristics of a
batch of containers is poor there is also a lack of accountability
as to which of the container or the cap is responsible.
[0006] In order to address the problems of leakage, there have in
recent years been proposed a large number of different designs of
cap. For example, in one design, the cap is provided with a top and
a downwardly extending skirt portion which depends from the top.
The skirt portion is provided on an inner surface with one or more
threads for engagement with one or more complimentary threads
provided on an outer surface of the container neck. A downwardly
depending annular plug is provided on an underside of the top,
spaced radially inwardly of the skirt. The plug is dimensioned to
engage a rim of the container opening defined by the neck so as to
form a primary seal. A secondary seal may be provided by means of
an annular bead or shoulder provided on the cap at or adjacent the
intersection of the top and the depending skirt such that, upon
application of the cap to the container neck, the bead or shoulder
engages an external surface of the neck at a location above the
threads. However, although commercially successful, this design of
cap does not adequately address the fundamental problem of
providing a reliable seal between a blow-moulded component and an
injection moulded component. Instead, leakage rates have been
reduced by providing ever increasing numbers of primary, secondary
and sometimes even tertiary sealing surfaces. However, on occasion,
the provision of so many seals can be counter productive and
actually cause leakage rates to rise as the interrelated tolerances
of the cap and neck result in clashes between the sealing
surfaces.
[0007] Another design of closure is described in GB-A-2,374,068. In
this document there is proposed a container comprising a
blow-moulded plastics body and an injection moulded neck and cap
assembly which can be fused to the body after the body has been
filled with a fluid. In other words, the closure to the container
comprises two parts, a neck and a cap, both of which may be
injection moulded to the same tolerances. This enables the cap and
neck, by virtue of their mutual cooperation, to provide a plurality
of reliable sealing surfaces. At the same time, the injection
moulded neck is permanently adhered to the blow-moulded plastics
body so as to prevent any leakage between the two.
[0008] Initially, the injection moulded neck is formed with a
membrane with which to close off the opening in the blow-moulded
plastics body. However, this membrane may be removed and discarded
by pulling on a pull-ring with which the membrane is provided. This
allows access to be gained to the contents of the blow-moulded
plastics body while the resealing capability of the closure is
provided by the engagement of an annular plug provided on an
underside of the cap with the bore of the injection moulded
neck.
[0009] This two part closure design clearly has the potential to
provide improved sealing characteristics. However, the use of the
described injection moulded neck inevitably adds to the height of
the packaged product as well as to the radial dimensions of the cap
with which it must interengage. As a result, the use of such a
closure necessitates the use of a dedicated bottling line which is
adapted to handle containers of a non-standard height. Likewise,
the use of a non-standard cap requires the adaptation of existing
capping equipment. All this imposes a considerable burden on those
responsible for the bottling plant and acts as a disincentive in
moving from one design of closure to another despite the
anticipated improvement in sealing characteristics that can be
expected to result.
[0010] Therefore, although it is known to overcome the difficulties
associated with providing a reliable resealable closure by
abandoning the previous attempt to design an injection moulded cap
capable of sealingly engaging with a blow-moulded container and
replacing it with a two part assembly, both parts of which may be
injection moulded with one part permanently adhered to the still
blow-moulded container and the other part providing resealable
engagement with the first part, nevertheless the problem of
providing such an assembly which is capable of being applied using
existing capping equipment still remains.
[0011] In particular, it would be desirable to provide a two part
assembly which is capable of being used with a container having a
standard silhouette and being of a conventional height. In this way
there would be no need for the various stations on a bottling line
to be specially adapted to accommodate a different shape or height
of bottle. Likewise, it would also be desirable to provide a two
part assembly in which the external dimensions of the cap, known as
the cap silhouette, were the same as an existing industry standard.
In this way, the two part assembly could be used with existing
"pick and place" equipment and with existing capping machines,
thereby removing the need for the bottling line to move over to new
or different equipment simply to process a batch of containers
having a different and otherwise highly desirable closure system.
The present invention seeks to address these desires.
[0012] According to a first aspect of the present invention there
is provided a closure for use with a container neck, the closure
comprising a cap and an insert, the insert being adapted to be
permanently adhered to the container neck and having a sealing
surface and the cap comprising a complimentary sealing surface for
sealable engagement with the sealing surface provided on the insert
and engagement means for releasable engagement with complimentary
engagement means provided on the container neck.
[0013] Advantageously the container neck may have a rim surrounding
an axial bore and the insert may be adapted to be received within
the bore, the insert having a flange adapted to project outwardly
from the bore to overlie the surrounding rim such that the insert
protrudes axially from the bore no more than the thickness of the
flange. This provides the advantage of restricting the height of
the insert above the container neck and so permits the use of a
conventionally dimensioned cap.
[0014] Advantageously the container neck may have an external neck
surface and the insert may be shaped such that no part of the
insert overlies the external neck surface. This provides the
advantage of restricting the dimensions of the insert in a plane
perpendicular to the axis of the bore and so once again permits the
use of a conventionally dimensioned cap.
[0015] According to a second aspect of the present invention there
is provided a closure for use with a container neck, the container
neck having a rim surrounding an axial bore and the closure
comprising a cap and an insert, the cap having a sealing surface
and the insert being adapted to be received within the bore and
permanently adhered to the container neck and having a
complimentary sealing surface for sealable engagement with the
sealing surface provided on the cap and a flange, the flange being
adapted to project outwardly from the bore to overlie the
surrounding rim such that the insert protrudes axially from the
bore no more than the thickness of the flange. This again provides
the advantage of restricting the height of the insert above the
container neck and so permits the use of a conventionally
dimensioned cap.
[0016] Advantageously the cap may be provided with engagement means
for releasable engagement with complimentary engagement means
provided on the container neck.
[0017] Advantageously the container neck may have an external neck
surface and the insert may be shaped such that no part of the
insert overlies the external neck surface. This again provides the
advantage of restricting the dimensions of the insert in a plane
perpendicular to the axis of the bore and so once more permits the
use of a conventionally dimensioned cap.
[0018] According to a third aspect of the present invention there
is provided a closure for use with a container neck having an
external neck surface, the closure comprising a cap and an insert,
the cap having a sealing surface and the insert having a
complimentary sealing surface for sealable engagement with the
sealing surface provided on the cap, the insert being adapted to be
permanently adhered to the container neck and shaped such that no
part of the insert overlies the external neck surface. This again
provides the advantage of restricting the dimensions of the insert
in a plane perpendicular to the axis of a bore defined by the
container neck and so once more permits the use of a conventionally
dimensioned cap.
[0019] Advantageously the cap may be provided with engagement means
for releasable engagement with complimentary engagement means
provided on the container neck.
[0020] Advantageously the container neck may have a rim surrounding
an axial bore and the insert may be adapted to be received within
the bore, the insert having a flange adapted to project outwardly
from the bore to overlie the surrounding rim such that the insert
protrudes axially from the bore no more than the thickness of the
flange. This again provides the advantage of restricting the height
of the insert above the container neck and so once more permits the
use of a conventionally dimensioned cap.
[0021] Advantageously the cap may comprise a top and a depending
side wall, the engagement means being provided on an interior
surface of the depending side wall. Advantageously the engagement
means may comprise a helical thread configuration. Alternatively
the engagement means may comprise a first formation adapted to be
snapped over and held in position by a second retaining formation
provided on the container neck.
[0022] Advantageously the bore may be cylindrical and the flange
may be adapted to project radially outwardly from the bore.
Advantageously the external dimension of the flange may be less
than that of the rim it is adapted to overlie. Advantageously the
flange may incorporate a pour lip. Advantageously the flange may be
adapted to be permanently adhered to the container neck.
Advantageously an undersurface of the flange may incorporate a
recess for the receipt of a sealing medium with which to
permanently adhere the insert to the container neck.
[0023] Advantageously the insert may be adapted to be wholly
received within the external dimensions of the cap. Advantageously
the cap may have the same silhouette as that of a conventional cap
thereby enabling the closure to be applied using existing capping
equipment.
[0024] Advantageously the container neck may define a bore and the
insert may comprise a wall adapted to be received within the bore,
an interior surface of the wall defining the sealing surface
provided on the insert and an exterior surface of a plug provided
on the cap defining the complimentary sealing surface provided on
the cap. Preferably the bore and wall are cylindrical and the plug
provided on the cap is annular.
[0025] Advantageously the insert may be provided with a removable
membrane with which to close off the container neck. Preferably the
removable membrane may be at least in part defined by a frangible
line of weakness and may be provided with a pull-ring with which to
separate the membrane from the remainder of the insert.
Advantageously at least a portion of the removable membrane may be
concave.
[0026] Advantageously both the cap and the insert may comprise
injection moulded plastics components.
[0027] According to a fourth aspect of the present invention there
is provided a closure in combination with a container having a
container neck, the closure being as previously described.
Advantageously the container and container neck may be of a
conventional design thereby enabling the container to be
manipulated on a production line using existing equipment.
[0028] According to a fifth aspect of the present invention there
is provided a closure in combination with a container having a
container neck defining a bore, the closure comprising a cap and an
insert, the insert being permanently adhered to the container neck
and comprising a wall received within the bore and the cap
comprising a plug which sealingly engages with an interior surface
of said wall at a location within the container neck. This provides
the advantage of enabling the strength of the container neck to
contribute towards the adequacy of the seal.
[0029] Advantageously, at the location of sealing engagement, the
wall of the insert may be interposed between the plug and a surface
of the container neck defining the bore. Advantageously the plug
may be formed so as to not only sealingly engage with an interior
surface of the wall but also to urge an external surface of the
wall into sealing engagement with a surface of the container neck
defining the bore. Advantageously the insert may be formed of low
density polyethylene (LDPE) and the cap may be formed of high
density polyethylene (HDPE). Advantageously the closure may have
any of the additional features previously described.
[0030] An embodiment of the present invention will now be described
by way of example with reference to the accompany drawings in
which:
[0031] FIG. 1 is a perspective view of a container neck and a
closure;
[0032] FIG. 2 is an exploded view of the container neck of FIG. 1
and showing the closure to comprise a cap and an insert received
within the container neck;
[0033] FIG. 3 is an exploded view of the container neck of FIG. 1
and showing the closure to comprise a cap, an insert and a sealing
medium;
[0034] FIG. 4 is a cross-sectional view of the container neck of
FIG. 1 with the closure applied to the container neck;
[0035] FIG. 5 is an enlarged cross-sectional view of a detail of
FIG. 4;
[0036] FIG. 6 is a perspective view of an insert forming part of
the closure;
[0037] FIG. 7 is a cross-sectional view of the insert of FIG. 6
taken along line VII-VII;
[0038] FIG. 8 is a cross-sectional view of the insert of FIG. 6
taken along line VIII-VIII; and
[0039] FIG. 9 is a cross-sectional view of an alternative design of
container neck and showing an alternative design of cap, the
alternative designs of neck and cap cooperating to provide the
closure with a tamper-evident capability.
[0040] Referring to the accompanying drawings and in particular
FIGS. 4 and 5 there is shown a neck 10 of a container 12, an insert
14 received within the neck 10, and a cap 16 which engages with
both the neck 10 and the insert 14. Together, the insert 14 and cap
16 define a closure 18 for the container 12.
[0041] The container 12 may be of any conventional design. In
particular, the body shape of the container 12 may take any
suitable form and may, for example, be of square, rectangular or
circular cross-section. Likewise, an integral handle may be formed
as part of the body shape.
[0042] The profile of the neck 10 is preferably also of a
conventional design and may, for example as shown in FIG. 9,
comprise a pull-up neck finish formed as a result of a blow pin
being pulled up through an annular shear steel to create a neck
opening having a relatively thin, but generally smooth, annular
rim. Alternatively, the neck 10 may comprise a ram-down neck finish
formed as a result of a technique in which a blow pin and cutting
ring are rammed down through an annular shear steel to produce a
neck opening which is surrounded by a much more rigid perimeter and
which contains far more plastics material than its pull-up
counterpart. As will be readily appreciated by those skilled in the
art, the embodiment illustrated in FIGS. 3 to 5 shows a container
12 having just such a ram-down neck finish as evidenced by the
characteristic annular wall which projects upwardly from a radially
inner edge of the annular rim and which is known in the art as a
chimney.
[0043] The profile of the neck 10 is shown in more detail in FIGS.
3 to 5 to comprise a radially extending rim 20 which merges, at a
radially inner end, with the chimney 22. The chimney 22 is in turn
defined by an upwardly extending, radially outer wall 24; an upper,
generally horizontal surface 26; and a downwardly extending,
radially inner wall 28.
[0044] At a radially outer end, the rim 20 merges with a downwardly
extending neck stretch portion 30 which is provided, on an exterior
surface, with engagement means 3? with which to engage
complimentary engagement means provided on the cap 16. In the
example shown, the engagement means 32 takes the form of a male
helical thread configuration comprising a single start. It will be
apparent however, that the engagement means 32 may take a number of
different forms and, in particular, may not be limited to a single
thread or lead but may comprise two, three, four or more threads as
appropriate. For example, the engagement means may comprise five,
six, seven or eight threads if so desired. Indeed, although not
illustrated, for certain packaging requirements a plurality of
threads may be preferable.
[0045] In the illustrated embodiment, the single thread extends
approximately 450.degree. around the circumference of the neck
stretch portion 30. Once again however, it will be understood that
threads of a lesser or greater extent may also be employed. For
example, in a four start thread configuration, each thread may
extend within a range from 90.degree. to more than 360.degree..
[0046] Preferably the helical thread configuration has a fine
thread density to limit the vertical float of the cap 16 on the
neck 10. Thus, the thread density preferably lies within the 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.
[0047] Below the engagement means 32, the neck stretch portion 30
merges with a generally horizontal, radially extending wall 34.
This generally horizontal, radially extending wall 34 merges, at a
radially outer end, with an arcuate wall portion 36 before in turn
merging with a downwardly and radially outwardly extending wall 38.
The precise direction and extent of the downwardly and radially
outwardly extending wall 38 are determined by the shape of the
container 12 which, as stated previously, may be entirely
conventional, and forms no part of the present invention.
[0048] Irrespective of the neck finish, the container 12 may be
blow-moulded from high density polyethylene (HDPE) so as to have a
typical wall thickness of between 0.1 mm and 11.0 mm. A container
having a wall thickness of less than 0.1 mm is unlikely to have the
necessary structural integrity to hold its shape when filled with
fluid. For a milk container having a capacity of up to six pints
(3.41 litres) a wall thickness of between 0.4 mm to 0.6 mm is
preferred.
[0049] The cap 16 which forms part of the closure 18 preferably has
a conventional silhouette. In other words, its external dimensions,
for example, its height and diameter, are the same as those of
existing caps and may therefore be handled using existing capping
equipment.
[0050] As shown in FIGS. 4 and 5 the cap 16 comprises a circular
top 40 which merges at a radially outer edge with a depending
annular side wall 42. The depending annular side wall 42 terminates
at an end remote from the circular top 40 in a generally horizontal
annular surface 44 while, on an exterior surface, the depending
annular side wall 42 is provided with a plurality of
circumferentially spaced, vertically extending ribs 46 which serve
as knurls to facilitate the gripping of the cap 16 by a user. In
contrast, on a radially inner surface, the depending annular side
wall 42 is provided with complimentary engagement means 48 for
repeated and releasable engagement with the engagement means 32
provided on the neck 10. As before, this engagement means 48 may
take many forms but, in the example shown, comprises a male helical
thread configuration having a single start and a thread density of
approximately 81/2 threads per linear inch. Once again, however, it
will be appreciated that the complimentary engagement means 48 need
not be limited to a single thread or lead but may comprise two,
three or four threads as appropriate. Indeed, the complimentary
engagement means 48 may comprise five, six, seven or eight threads
if so desired. Indeed, as with the engagement means 32, for some
packaging requirements it may be preferable for the complimentary
engagement means 48 to comprise a plurality of threads.
[0051] In the illustrated embodiment the single thread extends
about 450.degree. around the inner surface of the depending annular
side wall 42. Once again however, it will be understood that
threads of a lesser or greater extent may also be employed. For
example, in a four start thread configuration, each thread may
extend within a range from 90.degree. to more than 360.degree..
[0052] Likewise, although a thread density of approximately 81/2
threads per linear inch is preferred, so as to limit the vertical
float of the cap 16 with respect to the neck 10, nonetheless the
thread density may differ from this figure. Preferably however, the
thread density lies within a range of between 6 and 12 threads per
linear inch.
[0053] As will be apparent to those skilled in the art, if one of
the engagement means 32 or 48 comprises a male helical thread
configuration, then the other of the two engagement means may
comprise a helical groove configuration.
[0054] The two thread configurations 32 and 48 may be shaped so as
to slip past one another and engage when a direct, axial downward
force is applied to the cap 16 urging the cap into engagement with
the neck 10. In other words, when the cap 16 is pushed onto the
neck 10, the thread 48 on the cap snaps over and engages the thread
32 on the neck. This may be made possible by appropriate shaping of
the threads 32 and 48, for example, by forming the threads with an
asymmetric cross-section or by making them less pronounced.
Alternatively, if it is desired to rotate the cap 16 onto the neck
10, the threads may be of symmetrical, as opposed to asymmetrical
cross-section and may be more pronounced.
[0055] In addition to the complimentary engagement means 48, the
interior of the cap 16 is also provided with an annular plug 50
which depends from an undersurface 52 of the circular top 40 and is
spaced radially inwardly of the depending annular side wall 42. The
annular plug 50 is defined by respective radially inner and outer
walls 54 and 56, the radially outer plug wall 56 merging at an end
remote from the circular top 52 with a generally downward and
radially inwardly directed surface 58. This downwardly and radially
inwardly directed surface 58 intersects the radially inner plug
wall 54 and, together, serves to provide the annular plug 50 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 56 extends in a direction
substantially perpendicular to the plane of the undersurface 52,
the radially inner plug wall 54 extends from the undersurface 52 in
a direction which is both downwardly and radially outwardly.
[0056] Elsewhere, as it common with a number of caps, a small
downwardly directed dimple 60 is formed in the centre of the
circular top 40 so that any flash left after the cap 16 has been
moulded does not project above a plane defined by the upper surface
of the circular top 40.
[0057] The insert 14 which is received within the neck 10 of the
container 12 is defined, in part, by a downwardly extending
cylindrical wall 62. At an upper end, the downwardly extending
cylindrical wall 62 merges with a radially outwardly extending
annular flange 64 while at an opposite, lower, end the downwardly
extending cylindrical wall 62 merges with a generally downwardly
and radially inwardly directed annular wall 66 of arcuate
cross-section. This wall 66 of arcuate cross-section terminates in
an upwardly and radially inwardly directed annular surface 68 which
would define a circular aperture but for the provision of a
membrane 70 which spans the opening defined by the upwardly and
radially inwardly directed annular surface 68. The membrane 70 is
joined to the generally downwardly and radially inwardly directed
annular wall 66 by means of a narrow annular web 72 which
interconnects an upper, radially inner corner of the generally
downwardly and radially inwardly directed annular wall 66 with a
lower, radially outward corner of the membrane 70. As for the
membrane 70, it is defined by a substantially horizontally
extending outer annular portion 74 which merges with a central,
circular, concave portion 76.
[0058] A pull-ring 78, defined by an annular band 80, merges with
the membrane 70 via a connection 82. The connection 82 merges with
the membrane 70 at a location radially inward of, and adjacent to,
the annular web 72 such that the pull-ring 78 is joined to the
substantially horizontally extending outer annular portion of the
membrane 74 as opposed to the central, circular, concave portion
76. The annular band 80 is sized so as to be located within the
insert 14 below the level of the radially outwardly extending
annular flange 64 and is provided with radiused upper and lower
external surfaces 84 and 86 so as to provide a comfortable surface,
devoid of sharp edges, for a user's finger to pull against. The
concave nature of the central circular portion of the membrane 76
facilitates the gripping of the pull-ring 78 by creating an
increased void below the annular band 80 while, at the same time,
reducing the effects of shrinkage on the membrane tear line defined
by the narrow annular web 72. As illustrated, the connection 82
between the annular band 80 and the membrane 70 may be strengthened
by the provision of a pair of reinforcing gussets 88.
[0059] In contrast to the generally downwardly and radially
inwardly directed annular wall 66, the radially outwardly extending
annular flange 64 provided at an upper end of the downwardly
extending cylindrical wall 62 is defined by an upper surface which
slopes upwardly and radially outwardly before terminating in an
annular pour lip 92. At the same time, a lower surface of the
radially outwardly extending annular flange is provided with an
annular recess 94 which extends from the radially outer surface of
the downwardly extending cylindrical wall 62 and is bound, at an
end of the annular flange 64 remote from the cylindrical wall 62,
by a downwardly depending annular lip 96.
[0060] In order to assemble the closure 18 comprising the insert 14
and cap 16 to the container 12 a sealing medium 98 is applied to
the lower surface of the radially outwardly extending annular
flange 64 of the insert 14. The sealing medium 98 may be extruded,
sprayed, painted or otherwise applied. However, in the preferred
embodiment, the sealing medium 98 has sufficient structural
integrity to form an annular ring which can be received within the
annular recess 94. For example, the sealing medium 98 may comprise
an electrically conductive substrate coated on opposed surfaces
with respective first and second layers of an adhesive. The
electrically conductive substrate may be formed of any of the
materials traditionally used for providing a heat seal in existing
plastics containers and may, for example, comprise a metallic foil
such as an aluminium foil. Likewise, the layers of adhesive may be
of any commercially available type which is capable of bonding with
the surrounding plastics material once activated by, for example,
the application of heat.
[0061] Thus, in this embodiment, the first step in assembling the
closure 18 is to assemble the insert 14 and the sealing medium 98.
This may be achieved either by inserting the downwardly extending
cylindrical wall 62 through the central aperture of the annular
ring or else by inverting the insert 14 and pressing the annular
ring over the downwardly extending cylindrical wall 62. In either
case, the assembly is facilitated by the arcuate cross-section of
the generally downwardly and radially inwardly directed annular
wall 66. Although in the described embodiment the sealing medium 98
is received within the annular recess 94, nonetheless it is
preferably retained in place by means of a friction fit with the
radially outer surface of the downwardly extending cylindrical wall
62. Thus the provision of the downwardly depending annular lip 96
is preferably for cosmetic purposes only and serves to conceal the
presence of the sealing medium 98 rather than to retain it in
position. Indeed, in some embodiments, the downwardly depending
annular lip 96 may be omitted.
[0062] Having assembled the insert 14 and sealing medium 98, the
two are then assembled to the cap 16. The cap 16 is offered up to
the insert 14 and, in so doing, the annular plug 50 is received
within the blind bore defined by the downwardly extending
cylindrical wall 62. The receipt of the annular plug 50 in this way
is facilitated by the bevelled nature of the plug as a result of
the generally downward and radially inward directed surface 58.
Nonetheless, the annular plug 50 is so positioned as to be required
to flex radially inwardly in order to be received within the
aforementioned blind bore. In this way, once the annular plug 50
has been fully received, the resilience of the material forming the
plug causes the radially outer wall 54 to be urged into sealing
engagement with the inner surface of the downwardly extending
cylindrical wall 62.
[0063] It will be noted that the limit to which the annular plug 50
can be received within the blind bore defined by the downwardly
extending cylindrical wall 62 is determined by the engagement of
the upper surface 90 of the radially outwardly extending annular
flange 64 with the undersurface 52 of the circular top 40. However,
even in the fully received position, the pull-ring 78 is positioned
such that it remains spaced from and does not abut the cap 16.
[0064] The closure 18, comprising the insert 14 and cap 16 as well
as the sealing medium 98, is now fully assembled. However, all of
the components are received within the cap 16 with the result that
the external dimensions of the closure 18 are the same as those of
the cap 16 which, as stated previously, may be entirely
conventional. As a result the assembled closure 18 may be
manipulated and applied using conventional processing and capping
equipment.
[0065] To assemble the closure 18 to the container 12 the container
is first filled with the desired contents. Because the container 12
may be of a conventional design, this filling step may be performed
using existing equipment, as may its subsequent processing
elsewhere along the production line. Once the container 12 has been
filled, the assembled closure 18 is offered up to the neck 10 in
such a way that the generally downwardly and radially inwardly
directed annular wall 66 of the insert 14 is received within the
bore defined by the downwardly extending, radially inner wall 28 of
the chimney 22. Continued downward pressure of the closure 18 onto
the neck 10 causes the downwardly extending, radially inner wall 28
of the chimney 22 to slide along the radially outer surface of the
downwardly extending cylindrical wall 62 until such time as the
upper, generally horizontal surface of the chimney 26 engages the
sealing medium 98 received within the annular recess 94. In so
doing, as the downwardly extending, radially inner wall 28 nears
the end of its travel, so the annular plug 50 is once again caused
to flex radially inwardly to accommodate both the annular plug 50
and the downwardly extending cylindrical 62 within the bore defined
by the chimney 22. As before, the radial inward flexing of the
annular plug 50 is facilitated by the generally downward and
radially inward directed surface 58 while the resilience of the
material forming the annular plug 50 ensures that, afterwards, the
annular plug is not only urged into sealing engagement with the
inner surface of the downwardly extending cylindrical wall 62 but
also that the outer surface of the downwardly extending cylindrical
wall 62 is urged into sealing engagement with the downwardly
extending, radially inner wall 28 of the chimney 22.
[0066] At the same time as the insert 14 is received within the
bore defined by the chimney 22, so the depending annular side wall
42 of the cap 16 passes over the downwardly extending neck stretch
portion 30. This brings the engagement means 32 into engagement
with the complimentary engagement means 48. As stated previously,
these two engagement means 32 and 48 may be shaped so as to slip
past one another when a direct, axially downward force is applied
to the cap 16 urging the cap into engagement with the neck 10. In
other words, as the closure 18 is pushed onto the container 12, so
the threads on the cap 16 snap over and engage the threads on the
neck 10.
[0067] In an alternative embodiment the threads on the cap 16 and
the threads on the neck 10 may be shaped so as to require the
closure 18 to be rotated onto the container 12. Nonetheless, the
downwardly extending cylindrical wall 62 of the insert 14 is still
fully received within the bore defined by the downwardly extending,
radially inner wall 28 of the chimney 22.
[0068] Once the closure 18 has been fully applied to the container
12, the assembled closure and container are exposed to a time
varying magnetic field which gives rise to eddy currents within the
electrically conductive substrate of the sealing medium 98 with the
resultant generation of heat. This heat in turn activates the
layers of adhesive and bonds the radially outwardly extending
annular flange 64 to the upper, generally horizontal surface 26 of
the chimney 22. If necessary, some pressure may be applied to hold
the closure 18 firmly against the container 12 during the bonding
process.
[0069] Although the sealing medium 98 has been described as
comprising two layers of a heat-activated adhesive, one on each
side of the central electrically conductive substrate, it will be
apparent that the insert 14 and neck 10 may nevertheless be
permanently bonded together using only a single layer of
heat-activated adhesive provided that sufficient adhesive is
present within the annular space defined between the cooperating
parts of the fitment and neck and provided that the adhesive is
capable of flowing into contact with the surfaces defining that
space. To that end, the electrically conductive substrate may be
provided with one or more apertures to permit the flow of adhesive
from one side of the substrate to the other.
[0070] In another embodiment the sealing medium 98 may comprise a
sealing compound, and in particular may comprise a pressure
adhesion compound such that, upon application of a closing pressure
to either the closure 18 or the container 12, the insert 14 is
permanently bonded to the neck 10. Alternatively, the sealing
medium 98 may be a compound which is activated when exposed to
microwave radiation. In yet another currently preferred embodiment,
the sealing medium 98 is a composition that permanently bonds the
insert 14 to the neck 10 when the sealing compound is softened or
melted by inductive and/or capacitive heating. To this end, once
the closure 18 has been applied to the container 12, the assembled
closure and container are exposed to a time varying magnetic field
in the case of inductive heating or a time varying electric field
in the case of capacitive heating. In either case, heat is
generated within an inductive and/or capacitive material contained
within the composition. This heat is then transferred to the rest
of the composition and the composition then either softens or melts
so that it flows into more intimate contact with the surfaces of
the annular space defined between the cooperating parts of the
insert and neck structures. Upon cooling, the composition hardens
to provide a permanent weld or seal that bonds the insert 14 to the
neck 10.
[0071] Once the insert 14 has been adhered to the neck 10, the
container 12 may be opened by unscrewing and removing the cap 16.
This exposes the pull-ring 78 which may be gripped by a finger of
the user and pulled. The force imparted to the annular band 80 is
transferred, via connection 82, to the membrane 70 which tears away
from the generally downwardly and radially inwardly directed
annular wall 66 along the line of weakness defined by the narrow
annular web 72. Once the pull-ring 78 and the membrane 70 to which
it is attached has been discarded, the contents of the container 12
may be dispensed in the usual way.
[0072] To re-close the container 12, the cap 16 is simply presented
to the neck 10 in such a way that the helical thread configuration
48 on the cap engages the helical thread configuration 32 on the
neck. As the cap 16 is screwed home so the generally downward and
radially inward directed surface 58 of the annular plug 50 engages
the radially inner surface of the downwardly extending cylindrical
wall 62. This causes the annular plug 50 to flex radially inwardly.
Once the cap 16 has been fully applied to the neck 10, the
resilience of the material forming the annular plug 50 ensures that
the radially outer wall of the plug 56 is urged into sealing
engagement with a radially inner surface of the downwardly
extending cylindrical wall 62 and that a radially outer surface of
the downwardly extending cylindrical wall 62 is urged into sealing
engagement with the downwardly extending, radially inner wall 28 of
the chimney 22.
[0073] Because both the insert 14 and cap 16 may be injection
moulded and therefore made to the same tolerances, it is
anticipated that a reliable reseal may be obtained every time and
that, strictly speaking, no secondary seal is required.
Nonetheless, a secondary seal may be provided radially outwardly of
the chimney 22 at the point of engagement between the upper surface
90 of the radially outwardly extending annular flange 64 and the
undersurface 52 of the circular top 40.
[0074] The cap 16 may be screwed on and off the neck 10 as many
times as is required.
[0075] It will be noted that because the sealing medium 98 is
located within a space which does not communicate with the interior
of the container 12 there is little risk of the sealing medium
tainting or otherwise affecting the contents of the container.
Likewise, because the insert 14 is provided with a downwardly
extending cylindrical wall 62 which sealingly engages against the
downwardly extending, radially inner wall 28 of the chimney 22,
there is little likelihood of the contents of the container leaking
out past the sealing medium 98 between the insert 14 and the neck
10.
[0076] It will also be noted that because both the effective size
of the container opening (defined by the diameter of the upwardly
and radially inwardly directed annular surface 68) and the annular
pour lip 92 are both defined by the same injection moulded
component, the relationship between the two can be optimised so as
provide the optimum pouring angle whilst retaining a practical
bore.
[0077] Whilst the application of the closure 18 has been described
with reference to a ram-down neck finish, it will be understood
that the present invention may also be applied to a pull-up neck
finish. Indeed, the only difference between the two resides in the
fact that, in the absence of the chimney 22, the sealing medium 98
serves to bond the underside of the radially outwardly extending
annular flange 64 to the radially extending rim 20 rather than to
the upper, generally horizontal surface 26. Nonetheless, the
downwardly extending cylindrical wall 62 can still be received
within the bore defined by the radially extending rim 20 where, as
before, it will be in sealing engagement with both the radially
extending rim 20 and the annular plug 50. Thus, in all material
respects the closure 18 may be applied, opened and resealed to a
ram-down neck finish as described above. In particular, it will be
noted that, notwithstanding the absence of the chimney 22, the
sealing medium 98 is still contained within an annular space which
does not communicate with the interior of the container 12.
[0078] With containers having either a pull-up or ram-down neck
finish the provision of the downwardly depending annular lip 96
serves to conceal the presence of a sealing medium 98.
[0079] Although in the embodiment described the closure 18 has not
been provided with any tamper evidence capability, it will be
understood that this could also be provided. Indeed, since one of
the advantages of the present invention is that it may find use
with conventional containers 12 and makes use of caps 16 having a
conventional silhouette, if those conventional containers and caps
incorporate tamper evidence means, then so to may the present
invention. One such example is illustrated in FIG. 9.
[0080] Although the engagement means 32 provided on the neck 10 and
the complimentary engagement means 48 provided on the cap 16 have
been described in terms of a helical thread or groove
configuration, nonetheless the two sets of engagement means 32 and
48 may simply comprise a snap-band and cooperating retaining bead.
Alternatively, the engagement means 32, 48 may rely upon nothing
more than a friction or interference fit. Under such circumstances
the resulting cap may be presented as a push-on cap rather than of
the screw-on variety.
* * * * *