U.S. patent application number 12/812958 was filed with the patent office on 2010-11-11 for closure with safety feature.
Invention is credited to Gerry Mavin, Timothy Stephenson.
Application Number | 20100282747 12/812958 |
Document ID | / |
Family ID | 40501784 |
Filed Date | 2010-11-11 |
United States Patent
Application |
20100282747 |
Kind Code |
A1 |
Mavin; Gerry ; et
al. |
November 11, 2010 |
CLOSURE WITH SAFETY FEATURE
Abstract
Disclosed is a closure for a container wherein the container may
experience an excessive buildup of internal pressure. The closure
is equipped with a "blowout" portion which partially separates from
the remaining closure portion if internal pressure exceeds a
predetermined limit. The separation occurs at a line of weakness.
The line of weakness is specially designed to withstand external,
incidental pressure resulting from normal handling yet fracture in
a controlled fashion should internal pressure exceed a
predetermined amount. In this way inconvenience and possible hazard
is avoided from a closure completely separating from the container
from excessive pressure.
Inventors: |
Mavin; Gerry; (
Northumberland, GB) ; Stephenson; Timothy; (South
Yorkshire, GB) |
Correspondence
Address: |
ADAM K. SACHAROFF;MUCH SHELIST DENENBERG AMENT & RUBENSTEIN
191 N. WACKER DRIVE, Suite 1800
CHICAGO
IL
60606-1615
US
|
Family ID: |
40501784 |
Appl. No.: |
12/812958 |
Filed: |
January 16, 2009 |
PCT Filed: |
January 16, 2009 |
PCT NO: |
PCT/IB2009/005017 |
371 Date: |
July 15, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61021933 |
Jan 18, 2008 |
|
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Current U.S.
Class: |
220/203.29 |
Current CPC
Class: |
B65D 51/1638
20130101 |
Class at
Publication: |
220/203.29 |
International
Class: |
B65D 51/16 20060101
B65D051/16 |
Claims
1. A closure having a top sized to cover and seal a container
orifice, wherein said top comprises a pressure relief portion, said
pressure relief portion joined to the remainder of said top through
a frangible line of weakness.
2. A closure as in claim 1 wherein said line of weakness is
designed to resist external pressure on said pressure relief
portion and to fracture in a controlled fashion in response to
pressure on said pressure relief portion exceeding a predetermined
value.
3. A closure as in claim 2 wherein said line of weakness varies in
strength along its length.
4. A closure having a top and a skirt depending from a peripheral
edge of the top and further comprising a breakaway portion joined
by a line of weakness to an annular peripheral portion defined on
the top, wherein the breakaway portion includes a first extending
portion extending towards the annular peripheral portion and
wherein the annular peripheral portion includes a second extending
portion extending towards the breakaway portion, the first and
second extending portions overlapping to define an overlapping
region.
5. The closure of claim 4 further comprising: a seal plug depending
from a bottom surface of the top, the seal plug shaped to form a
hollow cylinder and having a smooth external surface intended to
seal against an internal surface of a container neck.
6. The closure of claim 5, wherein the first extending portion of
the breakaway portion overlaps on top of the second extending
portion of the annular peripheral portion, wherein pressure applied
downwards on the top causes the seal plug to press against the
internal surface of a container neck placing the overlapping region
in compression an insufficient force for tearing the line of
weakness, whereas pressure applied upwards on the bottom surface
places the overlapping region in tension such that the line of
weakness is capable of tearing.
7. The closure of claim 4, wherein the breakaway portion has a disk
shape.
8. The closure of claim 4, wherein the line of weakness extends as
an arcuate line of weakness.
9. The closure of claim 4, wherein the line of weakness extends in
an arc less than 360 degrees.
10. A closure having a top, a skirt depending from a peripheral
edge of the top, and a seal plug depending from a bottom surface of
the top, the seal plug shaped to form a hollow cylinder and having
a smooth external surface intended to seal against an internal
surface of a container neck, the closure further comprising: a
breakaway portion joined by a line of weakness to an annular
peripheral portion defined on the top, wherein the breakaway
portion includes a first extending portion extending towards the
annular peripheral portion and wherein the annular peripheral
portion includes a second extending portion extending towards the
breakaway portion, the first and second extending portions
overlapping to define an overlapping region, and wherein the first
extending portion of the breakaway portion overlaps on top of the
second extending portion of the annular peripheral portion, wherein
pressure applied downwards on the top causes the seal plug to press
against the internal surface of a container neck placing the
overlapping region in compression an insufficient force for tearing
the line of weakness, whereas pressure applied upwards on the
bottom surface places the overlapping region in tension such that
the line of weakness is capable of tearing.
11. The closure of claim 10, wherein the line of weakness extends
as an arcuate line of weakness.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to U.S. Provisional
Application 61/021,933 filed Jan. 18, 2008.
FIELD OF THE INVENTION
[0002] The present invention relates to a closure for containers
and to closures in combination with neck structures, and in
particular to closures suitable for applications that require
safeguard against accidental displacement of closures as resulting
from excessive internal pressure within the container void or head
space, such as the closure being propelled, or acting as a
projectile, away from the container.
BACKGROUND ART
[0003] In recent years with the increase in non-carbonated
beverages and still water drinks, the use of flat closures with
mechanical sealing features has become commonplace.
[0004] Since the containers do not contain carbonation, inert gas
is often "dropped" into the containers to maintain stability. The
containers include inert gas with internal pressures up to 2
bar(g). Inert gas is used because it limits the ingress of external
gases preventing the container from collapsing and assures product
life. The inert gas further provides for a cost effective
environmentally acceptable package.
[0005] When the containers can be filled under sterile conditions
an aseptic container is created. The aseptic container, when
correctly sealed, provides an extension of the product's shelf life
without the need to add preservatives or inhibitors to the product.
In other cases, fresh food products lacking preservatives may be
packaged under non-aseptic conditions but maintain their integrity
for some period, often under refrigerated conditions. However, if
the defined shelf life conditions are violated through improper
stock rotation or refrigeration, product spoilage may lead to
closure blow-off or "missiling". Such unintended closure
displacement is clearly both inconvenient and potentially
hazardous.
[0006] Conventionally, the closure is constituted by a main body
comprising a skirt or neck ring, of various diameters, which must
be applied onto the neck of a container. In most cases the skirt or
neck ring is threaded although this is not a requirement. Plug or
snap fitting closures may also be considered. A sealing device
attached to the inner face of the closure suitably comes into
contact the upper face or inner wall of the neck to form a
seal.
[0007] The main body of the closure is normally initially screwed
onto the neck of the container. However, in the case of familiar
snap-on/screw-off or snap-on/snap-off closures, initial application
may be achieved with a straightforward axially directed push.
[0008] As a guarantee of the integrity of the container, the
container can be provided with a form of tamper evidencing means
well known in the art. The means include breakaway bands, tear tabs
and the like which separate from the main closure body on initial
removal of the closure from the container neck.
[0009] The above-described closures normally effectively perform
their primary intended task. However, on occasion they suffer the
drawback that the integrity of seal is so effective pressure is
able to build up as a result of, for example, product reaction
(fermentation) or increase in gaseous pressure within the contained
void this as a result of expansion due to temperature or
overfilling.
[0010] This drawback has been dealt with typically, by installing a
mechanism to assist the release (venting) of excessive pressure
past the sealing mechanism(s) to atmosphere by permitting passage
of said gas or product between the closure and neck finish. An
example of such a device is disclosed within U.S. Pat. No.
7,314,146, the entire contents of which are herein incorporated by
reference. Unfortunately, such current venting systems occasionally
plug either through evaporation or with solid ingredients, such as
pulp, which may be present in the product. Any such plugging
thwarts the effectiveness of the intended venting mechanism.
DISCLOSURE OF INVENTION
[0011] The present invention thus includes an embodiment to provide
a closure for containers of liquids which solves some or all of the
above-mentioned drawbacks.
[0012] An embodiment of the present invention further provides for
a closure that can be easily sterilized internally with sanitizing
liquid according to known methods. An embodiment of the present
invention further provides for a closure that is able to operate
with pressures greater than 0.5 bar(g) and less than that
associated with carbonated products of the order of 3 bar(g)
without leakage or premature opening of the upper closure.
[0013] A further embodiment of the present invention further
provides for a closure that allows repeated opening and
re-closing.
[0014] Yet another embodiment of the present invention provides for
a closure that is able to give the user assurance, at the time of
purchase, of the integrity of the container, such that the user is
certain that the container has never been opened before.
[0015] Another embodiment of the present invention further provides
for a closure that can be manufactured at a cost, which is
appropriate for single use applications.
[0016] Another embodiment of the present invention provides a
breakaway shaped disc located within the sealed area of the closure
preferably though not necessarily in the portion forming the upper
section of package. (roof of cap)
[0017] A further embodiment of the present invention provides a
disc with a frangible connection able to displace more easily in an
outward direction as compared to inwardly in the event of excessive
internal pressure thereby avoiding incidental puncture during
consumer handling.
[0018] A further embodiment of the present invention is that the
breakaway disc should be larger than the depending opening along
sufficient land so as to inhibit accidental breakage of said
frangible connection in a downward direction.
[0019] A further embodiment of the present invention is that the
frangible connection should be interrupted in form adequately to
maintain attachment of a breakaway disc to the primary closure thus
avoiding choking risk and full dislodgement of the disc.
[0020] A further embodiment of the present invention is that
frangible line can be so formed in the top face so as to create a
pleasing shape in the form of a decorative logo or wording.
[0021] A further embodiment of the present invention is that the
frangible line defining a breakaway portion is able to be tapered
or graduated in form, thereby allowing gradual and increasing
breakage as pressure increases and limiting the risk of product
plugging.
[0022] A further embodiment of the present invention is that the
invention can be used in aseptically clean packages without risk to
the standard pack seal integrity.
[0023] A further embodiment of the present invention is that is can
be used in conjunction with primary venting mechanisms and in this
case of use act only as a final safeguard against entire blow-off
of the closure from the neck finish.
BRIEF DESCRIPTION OF DRAWINGS
[0024] The accompanying drawings which are incorporated in and form
a part of the specification illustrate preferred embodiments of the
present invention and, together with the description, serve to
explain the principles of the invention. In the drawings:
[0025] FIG. 1 is a side elevational view in section of an
embodiment of the instant invention;
[0026] FIG. 2 is an exploded view of the closure portion encircled
within the circle identified as "A" in FIG. 1;
[0027] FIG. 3 is a sectional view of the structure of a
conventional prior art tear line;
[0028] FIG. 4 is a perspective view from the top of an embodiment
of the instant invention; and
[0029] FIG. 5 is a top plan view of the closure of FIG. 4.
DESCRIPTION OF THE EMBODIMENTS
[0030] The aspects of the instant invention will now be described
in detail in conjunction with the descriptive figures. While the
invention is susceptible to embodiments in many different forms,
there are shown in the drawings and will be described herein, in
detail, the preferred embodiments of the present invention. It
should be understood, however, that the present disclosure is to be
considered an exemplification of the principles of the invention
and is not intended to limit the spirit or scope of the invention
and/or the embodiments illustrated.
[0031] Referring now to FIG. 1, there is shown a side elevational
view in section of a closure identified by numeral 10. Closure 10
comprises a top or "roof" 12 having a generally circular shape.
Closure 10 further comprises a skirt or "neck ring" 14 depending
from the peripheral edge of top 12. As best seen in FIG. 4, skirt
conventionally is of cylindrical form although this form is not a
requirement of the instant invention.
[0032] Skirt 14 has an internal surface 16 and external surface 18.
In the embodiment, a pattern of gripping knurls 20 is positioned on
external surface 18. Knurls 20 assure facile manipulation of
closure 10 by the consumer and further facilitate rotary
application of threaded closures. Closure 10 is further
characterized as having container engagement structure 22
positioned on the internal surface 16 of skirt 14. In the
embodiment, engagement structure 22 comprises internal helical
threads 24. As is known in the art, threads 24 are complimentary to
external threads (not shown) positioned of the external surface of
a suitable neck finish (not shown) of a container. The internal
threads 24 and mating external neck threads interengage to achieve
secure and facile application, removal, and reapplication of the
closure 10 relative the container. As is known in the art, other
disengageable features such as snap beads may often be substituted
for the complimentary thread structure of the embodiment.
[0033] Depending from closure top 12 is seal plug or valve 26. As
is known in the art, plug 26 is in the form of a hollow cylinder
depending from the bottom surface 28 of top 12. Plug 26 normally
has a smooth, seamless external surface 30 which is intended to
seal against an internal surface of a container neck (not
shown).
[0034] Depending from the lower edge of skirt 14 is a tamper
evidencing band 32. Band 32 is conventionally in the form of a
cylinder joined to the primary closure skirt 14 through a frangible
line of weakness 34. Internal locking structure 36 projects
radially inwardly from an internal surface of band 32. Locking
structure 36 may take many forms as is known in the art. The
function of locking structure 36 is to interengage with
complimentary external locking structure on a neck finish. The
engagement restricts upward movement of the band 32 during initial
closure removal from the container and the band separates from the
main closure at the line of weakness 34 during initial closure
removal.
[0035] In the embodiment of the instant invention shown in FIGS. 1,
2, 4 and 5, the closure top 12 comprises a "breakaway" portion 38
joined to an annular peripheral portion 40 through a line of
weakness 42. In the embodiment shown, the portion 38 has a
disk-like shape. Many other shapes are possible within the scope of
the invention. For example, the shape of the "breakaway" portions
may be provided within embossing features. Other geometrical shapes
in the form of a logo or other decorative designs are possible. The
possibility of this myriad of alternative "breakaway shapes" will
be clear in light of the instant teachings. In the embodiment
shown, the line of weakness 42 does not extend for a complete
circle. Thus the breakaway portion 38 defined by the line of
weakness 42 will not completely separate from the package to pose a
potential hazard.
[0036] The structure of the top frangible line 42 is best seen in
FIG. 2, a greatly exploded view of the encircled portion identified
as "A" in FIG. 1. In FIG. 2, it is seen that the line of weakness
42 in the embodiment is formed by overlap of extending portion 44
of breakaway portion 38 and extending portion 46 of peripheral
portion 40. The overlapping region, generally identified by numeral
48, forms a line of weakness 42 joining top portions 38 and 40.
Forming the frangible line of weakness 42 in this way achieves a
number of important advantages. First, it mitigates the possibility
of accidental rupture of the line of weakness due to inadvertent
pressure being applied from the exterior of the container. This is
because the frangible line 42 fails in tension rather than
compression. Inadvertent exterior pressure, generally indicated by
the arrow 50 in FIG. 2, would naturally be applied primarily to the
central blowout disk portion 38 of top 12, placing the frangible
overlap region 48 in compression. A tensile failure caused by
inadvertent external pressure applied to the peripheral portion 40
is prevented by the reinforcing structure present from the plug 26
and container neck finish. On the other hand, pressure from inside
the container is exerted primarily over the surface area of the
breakaway or blowout disk, thereby placing the frangible line in
tension. As can be seen from the sectional view shown in FIG. 3, a
conventional tear line formed using a thin score line is
essentially unable to discriminate between external and internal
pressure since the tear line is placed in tension in either
case.
[0037] Another important aspect, of the structural geometry of
frangible tear line 42 is that the actual strength of the tear line
can be easily varied at any point along its length. This variable
strength aspect is easily achieved by simply varying the width of
the overlapping region 48. For example, a graduated tear line
strength allows a gradual but predetermined release of any
excessive internal pressure thereby preventing explosive pressure
release.
[0038] The tear line structure embodied in FIG. 2 is achieved by
overlap of extending portions 44 and 46 which are shown to be
thinner than immediately adjacent portions 38 and 40 respectively.
This structural arrangement allows the closure top to maintain a
substantially constant thickness except for the region occupied by
the tear line. This characteristic is important should secondary
operations such as slitting to form frangible line 34 be
employed.
[0039] Finally, the tear line structure of FIG. 2 is characterized
by smooth accessible surfaces to allow facile sterilization for
aseptic packaging.
* * * * *