U.S. patent application number 11/891907 was filed with the patent office on 2009-02-19 for threaded closure with internal ribs.
This patent application is currently assigned to Alcoa Closure Systems International, Inc.. Invention is credited to Jordi Lluch Suriol.
Application Number | 20090045158 11/891907 |
Document ID | / |
Family ID | 40350965 |
Filed Date | 2009-02-19 |
United States Patent
Application |
20090045158 |
Kind Code |
A1 |
Suriol; Jordi Lluch |
February 19, 2009 |
Threaded closure with internal ribs
Abstract
An internally threaded plastic closure in accordance with the
present invention includes an array of axially extending,
circumferentially spaced internal ribs which intersect the internal
thread formation of the closure. By this arrangement, vent passages
are defined between adjacent ones of the internal ribs, thus
providing the closure with desirable gas venting characteristics,
while avoiding the provision of vent grooves extending into the
inside surface of the closure side wall, which can undesirably
impair the strength of the side wall. By the present construction,
the amount of polymeric material from which the closure is formed
can be desirably reduced, while maintaining the desired dimensional
characteristics of the closure, to facilitate use with existing
containers and high-speed capping equipment.
Inventors: |
Suriol; Jordi Lluch;
(Barcelona, ES) |
Correspondence
Address: |
WOOD, PHILLIPS, KATZ, CLARK & MORTIMER
500 W. MADISON STREET, SUITE 3800
CHICAGO
IL
60661
US
|
Assignee: |
Alcoa Closure Systems
International, Inc.
|
Family ID: |
40350965 |
Appl. No.: |
11/891907 |
Filed: |
August 14, 2007 |
Current U.S.
Class: |
215/256 ;
215/329; 215/344 |
Current CPC
Class: |
B65D 51/1688 20130101;
B65D 41/0471 20130101; B65D 41/0435 20130101; B65D 41/04 20130101;
B65D 41/3447 20130101; B65D 41/0407 20130101 |
Class at
Publication: |
215/256 ;
215/329; 215/344 |
International
Class: |
B65D 41/34 20060101
B65D041/34 |
Claims
1. A closure for a container, comprising: a molded plastic closure
cap formed from polymeric material, said closure cap including a
top wall portion, and an annular skirt portion depending from said
top wall portion, said closure including a sealing portion for
sealingly engaging an associated container, said skirt portion
including at least one helical, internal thread formation for
cooperating engagement with a thread formation on the associated
container, said skirt portion further including a plurality of
circumferentially spaced, axially extending ribs, at least some of
said axially extending ribs intersecting said internal thread
formation.
2. A closure for a container in accordance with claim 1, wherein:
said internal thread formation extends continuously about an inside
surface of said skirt portion.
3. A closure for a container in accordance with claim 1, wherein:
said internal thread formation is discontinuous, and comprises a
plurality of thread segments helically arranged about an inside
surface of said skirt portion.
4. A closure for a container in accordance with claim 4, wherein:
said discontinuous thread formation includes a plurality of
connector elements respectively extending between adjacent ones of
said thread segments on the inside surface of said skirt portion,
said connector elements each having a radial dimension less than a
radial dimension of said thread segments.
5. A closure for a container in accordance with claim 1, wherein:
said sealing portion of closure comprising at least one annular
sealing element depending from an inside surface of said top wall
portion of said closure cap.
6. A closure for a container in accordance with claim 1, wherein:
said sealing portion of said closure comprises a sealing liner
positioned within said closure cap adjacent said top wall
portion.
7. A closure for a container in accordance with claim 1, including:
an annular, tamper-evident band depending from said skirt portion
and at least partially, frangibly connected thereto.
8. A closure and container package, comprising; a container have a
neck portion having an external thread formation; and a closure
configured to be removably applied to said container, said closure
comprising a molded plastic closure cap formed from polymeric
material, said closure cap including a top wall portion, and an
annular skirt portion depending from said top wall portion, said
closure including a sealing portion for sealingly engaging said
container, said skirt portion including at least one helical,
internal thread formation for cooperating engagement with the
external thread formation on said container, said skirt portion
further including a plurality of circumferentially spaced, axially
extending ribs, at least some of said axially extending ribs
intersecting said internal thread formation, and defining a
plurality of vent passages between adjacent ones of said axially
extending ribs.
9. A closure and container package in accordance with claim 8,
wherein: said container defines at least one axially extending vent
groove intersecting said external thread formation.
10. A closure and container package in accordance with claim 8,
wherein: said internal thread formation of said closure is
discontinuous, and comprises a plurality of thread segments
helically arranged about an inside surface of said skirt
portion.
11. A closure and container package in accordance with claim 10,
wherein: said discontinuous thread formation includes a plurality
of connector elements respectively extending between adjacent ones
of said thread segments on the inside surface of said skirt
portion, said connector elements each having a radial dimension
less than a radial dimension of said thread segments.
12. A closure and container package in accordance with claim 10,
wherein: said internal thread formation extends continuously about
an inside surface of said skirt portion.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to molded plastic
closures used with associated containers such as for packaging
beverages, and more particularly to an internally threaded plastic
closure having an array of axially extending internal ribs which
can cooperate with an associated container to facilitate venting of
gas pressure from within the container during closure removal. The
internal ribs can also desirably be configured to provide the
necessary dimensioned characteristics while minimizing the quantity
of polymeric material from which each closure is formed in both
venting and non-venting closure applications.
TECHNICAL FIELD
[0002] Molded plastic closures which can be threadably applied to
associated containers for packaging products such as carbonated and
non-carbonated beverages have met with widespread success in the
marketplace. Closures of this nature can be efficiently formed by
compression molding and injection molding techniques, with the
closures configured for tamper-evidence as may be required for some
applications. These types of closures can provide highly effective
sealing performance, even when used with containers having
pressurized contents, with the threaded nature of the closures
facilitating convenient removal, and re-application, by consumers.
U.S. Pat. No. 4,938,370, No. 5,004,112, No. 5,167,335, No.
5,205,426, and No. 6,557,714, the disclosures all of which are
hereby incorporated by reference, illustrate molded plastic closure
constructions, and associated packages.
[0003] As will be appreciated, packaging of carbonated beverages
and like products requires closure sealing performance which
maintains the elevated level of gas pressure within the associated
container. However, during closure removal, it is desired for this
gas pressure within the associated container to be released prior
to disengagement of the closure threads from the external thread
formation of the associated container. To this end, the provision
of axially extending vent grooves in both containers and closures
is known in the art. The vent grooves typically traverse and
interrupt the closure or container threads, thus providing one or
more flow paths for gas pressure to be released from within the
container after the sealing interface between the closure and
container is broken, but prior to disengagement of the respective
thread formations. In current commercial embodiments of packaging
for carbonated beverages, both the container and the closure
typically define at least several axially extending vent grooves
traversing the respective thread formations, with maximum venting
performance typically occurring during alignment of the closure and
container vent grooves.
[0004] In a typical closure construction including axially
extending vent grooves, the vent grooves not only traverse the
closure thread formation, but typically extend partially into the
side wall of the closure to provide flow paths which permit gas
flow around the outer periphery of the associated container thread
formation. However, experience has shown that the regions at which
such axially extending vent grooves are formed in the side wall can
undesirably be prone to cracking or other failure, thus detracting
from the structural integrity and performance characteristics of
the closure.
[0005] The present invention is directed to an improved
configuration for an internally threaded plastic closure which can
be configured to facilitate gas venting, and which at the same time
permits formation of the venting and non-venting closures with a
relatively reduced quantity of polymeric material, while permitting
the closures to exhibit the necessary dimensional characteristics
so that the closures can be used in conjunction with conventionally
configured containers, and high-speed capping equipment.
SUMMARY OF THE INVENTION
[0006] The present invention is directed to an internally threaded
plastic closure having a plurality of circumferentially spaced,
axially extending vent grooves which intersect the thread formation
on the inside surface of a skirt portion of the closure. By this
arrangement, a plurality of vent paths are formed between adjacent
ones of the axially extending internal ribs, with each flow path
extending outwardly of the external thread formation of the
associated container. Because the vent paths are provided without
the formation of vent grooves or the like in the sidewall of the
closure, problems associated with closure failure at the vent
grooves are desirably avoided. Additionally, the provision of an
array of internal axially extending ribs permits fitting both
venting and non-venting closures to conventionally dimensioned
containers, while permitting the side wall of the closure to be of
a relatively reduced thickness for desirably reducing the quantity
of polymeric material from which each closure is formed.
[0007] In accordance with the illustrated embodiment, the present
closure comprises a molded plastic closure cap formed from
polymeric material, such as polypropylene, polyethylene,
copolymers, etc. The closure cap includes a top wall portion, and
an annular skirt portion depending from the top wall portion. The
closure includes a sealing portion for sealingly engaging an
associated container, which can be provided in the form of at least
one annular sealing element depending from the inside surface of
the top wall portion of the closure cap, or in the form of a
separate sealing liner positioned within the closure cap adjacent
to the top wall portion.
[0008] In order to facilitate threaded application of the closure
to an associated container, the skirt portion of the closure cap
includes at least one helical, internal thread formation for
cooperating engagement with an external thread formation on the
associated container.
[0009] In accordance with the present invention, the skirt portion
of the closure cap further includes a plurality of
circumferentially spaced, axially extending internal ribs, with at
least some of said axially extending ribs intersecting the internal
thread formation of the closure cap. By this arrangement, vent
passages are defined between adjacent ones of the internal ribs to
facilitate venting of gas pressure from within an associated
container during closure removal. Additionally, the provision of
the internal ribs permits the present closure to be fitted to a
conventionally dimensioned container, while permitting the side
wall of the closure cap to be of a relatively reduced thickness for
reducing the weight of the closure cap.
[0010] For non-venting closures for use on containers having
non-carbonated contents, the internal thread formation of the
closure cap can extend continuously about an inside surface of the
skirt portion. In illustrated embodiments, the internal thread
formation is discontinuous to define vent paths, and comprises a
plurality of thread segments helically arranged around the inside
surface of the skirt portion. In one of these embodiments, the
discontinuous thread formation includes a plurality of connector
elements respectively extending between adjacent ones of the thread
segments on the inside surface of the skirt portion. The connector
elements each have a radial dimension less than a radial dimension
of the thread segments, such that the venting capacity of the
closure is maintained, while providing closure threads which are
relatively more robust.
[0011] Other features and advantages of the present invention will
become readily apparent from the following detailed description,
the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a perspective view of an internally threaded
plastic closure having an array of internal ribs in accordance with
the present invention;
[0013] FIG. 2 is a perspective view of the neck portion of a
container to which the present closure can be applied;
[0014] FIG. 3 is an alternate embodiment of the present internally
threaded closure; and
[0015] FIG. 4 is a further alternate embodiment of the present
internally threaded closure.
DETAILED DESCRIPTION
[0016] While the present invention is susceptible of embodiment in
various forms, there is shown in the drawings, and will hereinafter
be described, presently preferred embodiments, with the
understanding that the present disclosure is to be considered as an
exemplification of the invention, and is not intended to limit the
invention to the specific embodiment illustrated.
[0017] With reference first to FIG. 1, therein is illustrated a
closure 10 embodying the principles of the present invention.
Closure 10 includes a molded plastic closure cap 12 formed from
polymeric material, such as polypropylene, polyethylene,
copolymers, and the like, as are known in the art.
[0018] The closure cap 12 includes a top wall portion 14, and an
annular skirt portion 16 depending from the top wall portion 14. In
the illustrated embodiment, closure 10 is configured for
tamper-evidence, and to this end, the closure includes an annular,
tamper-evident band 18 depending from skirt portion 16, and at
least partially frangibly connected to the skirt portion.
Tamper-evident band 18 may include one or more suitable engaging
elements 20 for cooperative engagement with an associated
container, whereby during closure removal the tamper-evident band
is at least partially detached from the skirt portion 16 to provide
readily visually discernible evidence that the closure has been
partially or completely removed from an associated container.
Tamper-evident band 18 can be frangibly connected to the skirt
portion 16 such as by a plurality of circumferentially spaced,
frangible bridges 22 which detachably connect the tamper-evident
band to the skirt portion. As illustrated in FIG. 2, container C
may include an annular locking ring L, or like element, for
cooperation with the engaging elements 20 of the tamper-evident
band 18 for effecting tamper-indication.
[0019] Threaded application of the closure 10 to an associated
container, such as container C illustrated in FIG. 2, is
facilitated by the provision of at least one helical thread
formation 24 provided on the inside surface of skirt portion 16 of
closure cap 12. The thread formation 24 is configured for
cooperative, threaded engagement with an external thread formation
T on container C, whereby relative rotation of the closure with
respect to the container effects application and removal of the
closure. In this illustrated embodiment, the thread formation 24 is
shown as discontinuous, and comprising a plurality of cooperating
thread segments to define a plurality of vent paths. However, for
use on containers having non-carbonated contents for which gas
venting may not be required, the thread formation 24 may be
continuous, such as illustrated in phantom line at 24'.
[0020] In order to provide the desired sealing cooperation between
the closure 10 and container C, the closure includes a sealing
portion for sealingly engaging the associated container. In the
embodiment of FIG. 1, the sealing portion of the closure 10 is
provided integrally with the closure cap 12, such as in the form of
an annular sealing element 26 depending from an inside surface of
the top wall portion 14 of the closure cap. Sealing element 26 can
be configured to fit generally within the open mouth of the
associated container to provide a so-called plug seal. As will be
recognized by those familiar with the art, the closure 10 may
include one or more additional sealing features, and may be
provided with a separate, typically disc-shaped sealing liner
positioned within the closure cap adjacent the top wall portion
14.
[0021] In order to facilitate release of gas pressure from within
container C during removal of closure 10 therefrom, the external
thread formation T of the container defines at least one axially
extending vent groove G intersecting and interrupting the external
thread formation T of the container. The provision of the vent
grooves G permits gas pressure from within the container to flow
generally between the inner peripheral edge of the closure thread
formation 24, and the exterior of the container finish after the
sealing portion of the closure has been moved out of sealing
cooperation with the container, during closure removal.
[0022] In order to further facilitate release of gas pressure from
within the container, and in accordance with the present invention,
closure cap 12 of closure 10 includes an array of internal ribs 28
positioned in circumferentially spaced relationship on the inside
surface of skirt portion 16, with at least some of the ribs 28
intersecting the internal thread formation 24. By the provision of
internal ribs 28, a plurality of gas passages are defined extending
along the inside surface of skirt portion 16, with each of the gas
passages facilitating flow of gas outwardly of the outer periphery
of the external thread T of container C. Each of the internal ribs
28 preferably has a radial dimension less than that of the
associated thread formation 24 to provide the desired plurality of
vent passages. By way of example, in a current embodiment having
twenty-four (24) of the internal ribs 28, each rib has a radial
dimension of 0.008 inches, while the associated thread formation
has a radial dimension of 0.040 inches.
[0023] As will be appreciated, the configuration of the present
closure, including the provision of internal ribs 28, desirably
configures the closure to provide the desired venting performance,
while avoiding the provision of vent grooves which extend into the
inside surface of sidewall 16, as in previous constructions. Any
weakening of the closure sidewall associated with these types of
previous vent grooves is thus desirably avoided.
[0024] Additionally, the provision of the internal ribs 28
desirably permits the closure 10 to be formed from less polymeric
material, desirably saving weight and cost. In particular, the
thickness of the sidewall 16 of the closure cap 12 can be
relatively reduced, while maintaining the conventional outside
dimension of the closure to facilitate application with existing
camping equipment. The internal ribs 28 can be dimensioned to
provide the desired cooperation with the external thread formation
T of the associated container, thus ensuring that each closure can
be properly fitted to an associated container.
[0025] A further benefit of the present invention relates to
cooperation of the internal ribs 28 with the external thread
formation T of the associated container, particularly at the vent
grooves G defined by the container. Heretofore, the provision of
rotation-inhibiting projections, sometimes referred to as "speed
bumps", on the inside surface of a closure is intended to cooperate
with the thread formation of the associated container to inhibit
free rotation of the closure on the container during closure
removal. By providing predetermined interference between such
projections and the container thread formation, closure removal is
effected over a time span which facilitates release of gas pressure
from within the associated container prior to disengagement of the
respective thread formations on the closure and container.
[0026] By the present construction, during closure removal the
internal ribs 28 are substantially continuously contacting the
external thread formation T of the container, particularly at the
vent grooves G, to create the desired resistance to free spin.
However, notwithstanding this desired resistance to free rotation,
experience has shown that the present closure remains desirably
convenient to remove, facilitating convenient use by consumers. By
way of example, a conventional closure may include two
rotation-inhibiting projections, with a standard container finish
having 4 vent grooves G. Thus, during each rotation of the closure
relative to the container, there are a total of 8 interfering
engagements of a projection with a vent groove (i.e., 2 projections
times 4 vent grooves). In contrast, the illustrated embodiment of
the present closure 10 includes twenty (20) of the
circumferentially spaced internal ribs 28. Thus, when the present
closure is fitted to a conventional container finish having four of
the vent grooves G, each turn of the closure relative to the
container creates 80 interfering engagements, which 76 is tactilely
perceived as smoother during closure removal. Thus, the desired
resistance to free spin of the closure on the container can be
achieved, while facilitating convenient consumer use.
[0027] As shown in phantom line at 24' in the embodiment of the
present closure illustrated in FIG. 1, internal thread formation 24
can extend continuously, without interruption, about the inside
surface of the closure skirt portion 16. The embodiments of the
present closure illustrated in FIGS. 3 and 4 each include
discontinuous internal thread formations, each formed by a
plurality of thread segments helically arranged about the inside
surface of the skirt portion of the closure.
[0028] In the embodiment of FIG. 3, a closure 110 includes elements
corresponding to those of the previous embodiment designated by
like reference numerals in the 100-series. Closure 110 includes a
discontinuous thread formation 124 comprising helically arranged
thread segments which are spaced from each other, and are otherwise
unconnected. Closure 110 includes a tamper-evident band 118 having
projections 120 which can be configured in accordance with the
teachings of U.S. Pat. No. 5,242,068, hereby incorporated by
reference. The closure can be formed with a separate sealing liner
27.
[0029] In contrast, in the embodiment of FIG. 4, thread formation
24 includes thread segments which are spaced from each other, but
with connector elements 25 respectively extending between adjacent
ones of the thread segments. The connector elements each have a
radial dimension less than the radial dimension of the associated
thread segments, with the connector elements acting to provide a
more robust internal thread formation, which can desirably enhance
the hoop strength of the skirt portion. As will be appreciated, the
provision of the connector elements 25 acts to maintain the venting
performance achieved by the provision of the multiple vent passages
defined by the internal ribs 28.
[0030] Notwithstanding the relatively reduced side wall thickness
that can be achieved in accordance with the present invention, the
provision of internal ribs desirably acts to guide the present
closure onto the neck portion of the associated container during
high-speed application with automated capping equipment. As will be
appreciated, contact points of support are provided where each of
the internal ribs engages the outer periphery of the external
thread formation T of the container C, as opposed to engagement of
the container thread formation along the complete inside surface of
the skirt portion. Notwithstanding, the practical result of the
present invention is substantially the same for purposes of
high-speed, automated application. The internal ribs desirably act
to guide the closure during application travel, offering a better
level of adjusting. Ordinarily, designers must keep some clearance
between the closure and the container neck to avoid jamming in the
system. The internal ribs offer the advantage of working with
substantially zero clearance, since even with some interference,
the ribs can be easily deformed without blocking the system. This
offers the possibility to better fit and adjust onto the container
neck finish, despite typical tolerance issues. The closure is
desirably centered on the associated container, and desirably
resists cocking during high-speed operation, which can undesirably
result in improper application of a closure to an associated
container. As will be recognized by those familiar with the art,
any reduction in the quantity of material from which each closure
is formed can very desirably result in substantial cost
savings.
[0031] From the foregoing, it will be observed that numerous
modifications and variations can be effected without departing from
the true spirit and scope of the novel concept of the present
invention. It is to be understood that no limitation with respect
to the specific embodiments illustrated herein is intended or
should be inferred. The disclosure is intended to cover, by the
appended claims, all such modifications as fall within the scope of
the claims.
* * * * *