Note: Descriptions are shown in the official language in which they were submitted.
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CLOSURE SYSTEM
BAC,KGROUNQ OF THE IN1tENTION
(1) Field of the Invention
10001] The present invention relates generally to closure systems for
containers.
(2) Descri tign of the Related Art
[0002] Container clbsures are devices that seal the contents of a
container, thereby protecting the container contents from contamination,
oxygen, moisture, spillage and evaporation. Many types of closure
systems have emerged tp serve these functions. For example, two-piece
closure systems have frequently been employed in canning and other food
product applications. A two-piece closure system, also known as a
composite closure, is typically made up of a screw band and a disk. The
disk fits inside the band, between the band and the container. The disk
often has a peripheral rtaised bead with an underside adapted to contact
the land of the container. The disk may also have an annular ring of heat-
sensitive adhesive or sealant disposed on the underside of the peripheral
raised bead. This $ealdnt provides a sealing contact between the disk and
the land of the container and can prevent lateral movement of the disk.
[0003] The container is typically filled with a food or beverage product
before sealing the closLire system. The food or beverage product may be
commercially sterile. The closure system can then be applied to the
container. To close a container using a two-piece closure system, the disk
is typically placed upon the container to be sealed and a screw band is
loosely screwed over th~ disk onto the finish of the container. The screw
band often remains loose enough so that as the container is heated and
sterilized, venting of gases may take place under the dfsk. After heat-
processing, the screw band is tightened and the sealed container is
cooled. By virtue of the slow cooling of the container and its contents, the
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pressure within the container is reduced. This produces a partial vacuum
within the container, causing the disk to be firmly retained against the land
of the container and a hermetic seal to be formed. This type of closure is
beneficial because it can maintain product seal integrity during sterilization
and allows the container to be resealable by the consumer without the
need for a secondary inner seal.
SUMMARY OF THE INVENTION
[0004] Briefly, the present invention is directed to a novel closure
system comprising a container having a finish and a land located at the top
of the finish. The outer wall of the finish, just below the land, is vertical
and the land slopes downwardly, toward the outside of the container, at an
angle of between about 1 and 10 .
[0005] Also present is a band adapted to be received onto the finish of
the container. The band has a top portion and an annular lip extending
inwardly from the top portion. Additionally present is a disk adapted to be
received between the band and the container land. The disk has a raised
peripheral bead, the underside of the raised peripheral bead presenting a
downwardly facing channel which contains a gasket material. The ratio of
the width of the channel to the width of the container land is in the range of
about 2:1 to 1:1. When the disk is inserted into the band, the annular lip of
the band extends inwardly beyond the raised peripheral bead of the disk
and has a hook portion that engages the top and inside edge of the raised
peripheral bead.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] For a more complete understanding of the present invention,
reference is now made to the following descriptions taken in conjunction
with the accompanying drawings.
[0007] Figure 1 illustrates a cross-sectional view of a closure system of
an embodiment of the present invention in which the band is engaged with
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the disk and container land but not tightened onto the disk and container
land.
[0008] Figure 2 illustrates an exaggerated cross-sectional view of an
embodiment of a closure system of the present invention in which the
band is engaged with the disk and container land but not tightened onto
the disk and container land.
[0009] Figure 3 illustrates an exaggerated cross-sectional view of an
embodiment of a closure system of the present invention in which the
band is engaged with the disk and container land but not tightened onto
the disk and container land. In this embodiment, exemplary angles of the
land, channel, and top portion of the band are illustrated.
[00010] Figure 4 illustrates an exaggerated cross-sectional view of an
embodiment of a closure system of the present invention in which the
band is tightened onto the disk and container land, forcing the container
land into sealing contact with the gasket material.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[00011] Reference now will be made in detail to the embodiments of the
invention, one or more examples of which are set forth below. Each
example is provided by way of explanation of the invention, not a limitation
of the invention. In fact, it will be apparent to those skilled in the art
that
various modifications and variations can be made in the present invention
without departing from the scope or spirit of the invention. For instance,
features illustrated or described as part of one embodiment, can be used
on another embodiment to yield a still further embodiment.
[00012] Thus, it is intended that the present invention covers such
modifications and variations as come within the scope of the appended
claims and their equivalents. Other objects, features and aspects of the
present invention are disclosed in or are obvious from the following
detailed description. It is to be understood by one of ordinary skill in the
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art that the present discussion is a description of exemplary embodiments
only, and is not intended as limiting the broader aspects of the present
invention.
[00013] As used herein, the term "finish" means the top portion of a
container which surrounds the opening of the container and is configured
to accommodate a closure. For example, a finish is shown as 22 in the
Figures.
[00014] As used herein, the term "land" means the lip portion of the
finish which makes contact with the gasket material of the disk and forms a
seal. For example, a land is shown as 21 in the Figures.
[00015] The term "skirt" refers to the vertical wall of the band, extending
downwardly from the top portion of the band. For example, a skirt is
shown as 14 in the Figures.
[00016] The terms "raised peripheral bead" refer to a raised ring around
the circumference of the disk. For example, a raised peripheral bead is
shown as 32 in the Figures.
[00017] The term "gasket material" means any type of sealing material
that can be placed between the disk and container land in order to prevent
the escape of substances such as gas or fluid. For example, a gasket
material is shown as 34 in the Figures.
[00018] As shown generally in the figures, the present invention is
directed to a novel closure system 10 comprising a container 20 and a
closure engageable with that container 20. The closure of the invention
can comprise a two-piece composite closure. Generally speaking, a disk
30 fits inside a band 11, between the band 11 and the container 20. The
band 11 has a top portion 12, an annular lip 13 extending inwardly from
the top portion 12, and a skirt 14 extending downwardly from the top
portion 12. The disk 30 has a center portion 31 and a raised peripheral
bead 32 circumnavigating the center portion 31. The underside of the
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bead 32 can present a downwardly facing channel 33 which can contain a
gasket material 34. Under pressure, the gasket material 34 is designed to
seal the disk 30 to the container land 21.
[00019] The band 11 can be screwed onto the container via annular
threads 16 and 23, located on the outer surface of the container finish 22
and the inner surface of the band skirt 14, respectively. The annular
threads 16 and 23 are adapted to receive one another and provide a tight
fit between the band 11 and the container 20, thereby sealing the gasket
material 34 of the disk 30 against the land 21 of the container 20. In some
embodiments of the invention the annular threads 16 and 23 are
continuous annular threads. A continuous annular thread may be
comprised of an uninterrupted protruding helix. In certain other
embodiments the annular threads 16 and 23 are interrupted threads or
lugs. A lug thread may be designed so the thread segments are disposed
equidistantly around the container finish. The closure has matching
portions that engage each of the thread segments.
[00020] In an embodiment of the invention, at least one annular bead 40
is present on the upper surface of the top portion 12 of the band 11. In
some embodiments, two or three annular beads 40 may be located on the
upper surface of the top portion 12 of the band 11. The annular bead(s)
40 can be rounded, squared, or any other shape. The annular beads
provide the band 11 with additional structure and stability during the
tightening of the band onto the container. When the band of a typical two-
piece closure is screwed onto a container, uneven force may cause the
band to flex. The annular beads 40 located on the upper surface of the
top portion 12 of the band 11 provide the band with stability and reduce
unwanted flexing of the band.
[00021] In certain embodiments, the container land 21 slopes
downwardly, toward the outside of the container, at an angle A of between
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about 1 and 10 (shown in Figure 3). In certain embodiments, the
container land 21 slopes downwardly, toward the outside of the container,
at an angle A of between about 3 and 7 . In still other embodiments, the
container land 21 slopes downwardly, toward the outside of the container,
at an angle A of about 5 so that the inside edge of the container land is
about 5 higher than the outside edge of the container land.
[00022] The underside 19 of the top portion 12 of the band 11 and the
channel 33 can also slope downwardly, toward the outside of the closure
system, at angles B and C, respectively, which can correspond generally
to the angle A of the container land. In an embodiment of the invention,
the container land 21, disk channel 33 and top portion 12 each slope
downwardly, toward the outside of the container, at an angle of about 5 .
[00023] In some commercially available containers, the land area has a
downwardly sloping angle of about 15 . In contrast, a nearly flat land area,
between about 1 and 10 , allows thorough coverage of the gasket
material 34 over the container land 21 as the disk 30 is tightened onto the
container 20. Additionally, if the angle of the disk and band corresponds
with the angle of the container land, the seal area is further maximized.
[00024] In order to create the particular angle on the container land, the
container 20 can be extrusion molded and removed from the rotation
wheel, with excess plastic remaining on the finish as a moil. This material
can then be removed using a rotating knife blade. The knife blade can be
set at any angle, for example at 5 below flat surface. The knife blade
then separates the container from the moil at a 5 angle. This creates an
angle where the inside edge of the container land is slightly higher than the
outside edge of the container land. The nearly flat land area places a
more even distribution of the gasket material 34 onto the container land
21. The disk and band can be manufactured to provide corresponding
angles.
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[00025] In certain embodiments of the invention, the band 11 has a top-
centered opening 18. In this embodiment, the annular lip 13 defines a
peripheral edge 17 of a top opening 18. The disk 30 of the closure system
is inserted between the band 11 and the container land 21. It can be
5 received into the band 11 just below the inwardly extending annular lip 13
of the band 11. The disk 30 can be rotatably movable within the band 11.
Similarly, the band 11 can be rotatable while the disk 30 can be frictionally
held in place by the gasket material 34 and container land 21. When the
band 11 is tightened onto the container 20, the disk 30 provides a seal for
10 the container 20 (shown in Figure 4).
[00026] The gasket material-containing channel 33 is designed to form
a seal with the land 21 of the container 20. In an embodiment, the gasket
material 34 can be plastisol. Plastisol is a liquid mixture of resins and
plasticizers that is solidified with the application of heat. In an embodiment
of the present invention, a plastisol-lined disk forms an airtight seal
against
the container land to prevent the ingress of oxygen or other contaminants.
[00027] In some embodiments of the invention, when the disk 30 is
inserted into the band 11, the annular lip 13 of the band 11 extends
inwardly beyond the raised bead 32 of the disk 30 and has a hook portion
15 that engages the top and inside edge of the bead 32. In typical closure
systems, as the band is tightened onto the container land, the down force
caused by the application torque pulls to the outside of the disk insert. In
the present invention, however, as the band 11 is tightened onto the
container land 21, the hook portion 15 of the lip 13 applies force
downwardly on the top and inner edge of the bead 32, thereby creating an
equal downward force on the top, outer and inner surface of the land 21 of
the container. The container land can then create a channel in the gasket
material, forcing the gasket material to be distributed evenly across the
inside, top and outside of the container land. This provides a better seal
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for the gasket material on the container land and prevents the ingress or
egress of gaseous or liquid substances.
[00028] In certain other embodiments of the invention, the ratio of the
width of the channel 33 to the width of the container land 21 is in the range
of about 2:1 to 1:1. In particular embodiments the ratio of the width of the
channel 33 to the width of the container land 21 is in the range of about
1.75:1 to 1:1. In further embodiments the ratio of the width of the channel
33 to the width of the container land 21 is in the range of about 1.5:1 to
1:1. In yet another embodiment the ratio of the width of the channel 33 to
the width of the container land 21 is about 1.48:1. In these embodiments,
the width of the channel 33 is slightly larger than the width of the land 21
of
the container with which it engages. A relatively narrow channel 33 is
beneficial because as the disk 30 is pushed downwardly onto the container
land 21, the coverage area of the gasket material 34 in the channel 33 is
thoroughly distributed on the top, inside, and outside of the container land
21.
[00029] In a particular embodiment of the invention, the outer wall 24 of
the container finish 22, above annular threads 16 and just below the land
21, is vertical. Oftentimes, the outer wall of the container finish on
containers will angle slightly inwardly. This does not provide as a large a
contact area for the gasket material seal. Molding the outer wall 24 of the
finish 22 as a completely straight vertical wall increases the area of the
container land 21 in contact with and covered by the gasket material 34 in
the disk 30. This maximizes the seal contact area and creates a center
clamping force by the closure band 11 of equal amount over the top, inside
edge and outside edge of the container land 21.
[00030] In processing and sterilization, the container 20 of the present
invention can be filled with a food or beverage product before sealing the
closure system 10. The closure system 10 can then be applied to the
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container 20. The disk 30 can be placed upon the container 20 and the
band 11 screwed tightly onto the container 20. The container 20 can then
be heated and sterilized. The closure system 10 of the invention
beneficially maintains product seal integrity during sterilization and allows
the container 20 to be resealable by the consumer without the need for a
secondary inner seal.
[00031] The various components of the closure system of the present
invention can be produced from a variety of materials, including metals,
plastics or glass. In some embodiment of the invention each of the
container, disk and band may each be made of the same material, such as
plastic. In certain other embodiments, the container, disk and band may
all be made of different materials, such as a glass container, metal disk
and plastic band. In a particular embodiment, the container and band may
be plastic and the disk may be metal.
[00032] In one embodiment of the present invention the band is plastic.
In this embodiment, the band can be prepared from any plastic material,
including one or more selected from the group consisting of polyethylene,
polypropylene, polystyrene, cycloolefin copolymer, polyethylene
terephthalate, polyethylene naphthalate, ethylene-(vinyl alcohol)
copolymer, poly-4-methylpentene-1, poly(methyl methacrylate),
acrylonitrile, polyvinyl chloride, polyvinylidene chloride, styrene-
acrylonitrile, acrylonitrile-butadiene-styrene, polyamide, polyacetal,
polycarbonate, polybutylene terephthalate, ionomer, polysulfone, polytetra-
fluoroethylene, polyester, vinyl ester, polyurethane and polyurea. In a
particular embodiment, the band is prepared from polypropylene.
[00033] A plastic band offers advantages in that a plastic band does not
rust or corrode and can be reused many times without any deterioration of
its appearance. In certain embodiments of the band, the outside of the
skirt may have a plurality of vertical ribs or other gripping mechanisms
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designed to aid in the grasping and turning of the band. In other
embodiments, the band can be provided with tamper indicating means.
The band can have a detachable ring and, hinged to the detachable ring
along its lower end, a series of upwardly and inwardly projecting ratchet
fingers or tabs. In particular embodiments, the band may be injection
molded.
[00034] In an embodiment of the invention, the disk is metal. In a
particular embodiment, the disk is made from stainless steel. Optionally,
the disk can be semi-rigid. In this embodiment, the disk can have a central
portion sufficiently flexible to be drawn partially inward into the open mouth
of the container when the pressure within the container is less than the
pressure outside the container. The deflection of the central portion of the
disk provides a visual indication of the existence of a hermetic seal.
[00035] In certain embodiments, the container of the present invention
can be extrusion blow molded and can comprise any suitable plastic
material known in the art. The container can be of any size and should be
adapted to receive the corresponding two-piece closure system. In an
embodiment, the container may comprise a jar. In some embodiments,
the container may comprise a bottle, such as an infant or baby bottle. The
bottle may be filled with cow's milk, human breast milk or infant formula.
Once the closure of the present invention is applied to the bottle, the
system may be sterilized or otherwise processed.
[00036] If the bottle is used for cow's milk, human breast milk or infant
formula, the bottle may be filled and the disk of the system replaced with a
nipple. The band can then be tightened onto the nipple and container,
securing the nipple in place. The container and closure system can then
be used to feed an infant.
[00037] The closure system of the present invention is suitable for
multiple filling processes, including hot fill, cold fill, dry seal,
pasteurization
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and retort. The closure can be produced in a variety of sizes for a wide
range of food and beverage applications, such as pickled products,
sauces, jams, jellies, nuts, juices, milk-based beverages, and infant
formulas.
[00038] In certain embodiments, the disk and band may be made of
different colors improving the esthetics of the product package.
Additionally, the disk and/or band may be produced in a manner so that
they can be labeled for commercial purposes.
[00039] All references cited in this specification, including without
limitation, all papers, publications, patents, patent applications,
presentations, texts, reports, manuscripts, brochures, books, internet
postings, journal articles, periodicals, and the like, are hereby incorporated
by reference into this specification in their entireties to the extent that
they
are consistent with the disclosures herein. The discussion of the
references herein is intended merely to summarize the assertions made by
their authors and no admission is made that any reference constitutes
prior art. Applicants reserve the right to challenge the accuracy and
pertinence of the cited references
[00040] These and other modifications and variations to the present
invention may be practiced by those of ordinary skill in the art, without
departing from the spirit and scope of the present invention, which is more
particularly set forth in the appended claims. In addition, it should be
understood that aspects of the various embodiments may be interchanged
both in whole or in part. Furthermore, those of ordinary skill in the art will
appreciate that the foregoing description is by way of example only, and is
not intended to limit the invention so further described in such appended
claims. Therefore, the spirit and scope of the appended claims should not
be limited to the description of the preferred versions contained therein.
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