Note: Descriptions are shown in the official language in which they were submitted.
CA 02635086 2010-11-22
TITLE
POUCH AND AIRTIGHT RESEALABLE CLOSURE MECHANISM THEREFOR
[0001] Blank.
REFERENCE REGARDING FEDERALLY SPONSORED RESEARCH OR
DEVELOPMENT
[0002] Not applicable
SEQUENTIAL LISTING
[0003] Not applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0004] The present invention relates generally to a resealable closure
mechanism such as
may be used on a thermoplastic pouch.
2. Description of the Background of the Invention
[0005] Thermoplastic pouches having one or more resealable closure mechanisms
extending along an opening into an interior thereof are often used to store
perishable
contents, such as food. In order to keep the food stored inside the pouch
fresh for an
extended period, a user may press excess air out of the pouch before
completely sealing the
closure mechanism. Other pouches have been developed that have a separate air
evacuation
route so that air may be removed from the pouch after the closure mechanism
has already
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been sealed. Some such pouches allow a vacuum to be formed inside the pouch
before the
pouch is sealed so as to vacuum pack the contents of the pouch.
[0006] Special resealable closure mechanisms have been used in an attempt to
maintain
the vacuum in the pouch over extended periods of time. Those closure
mechanisms have two
opposing closure elements that form an interlocking section and a sealing
section in an
attempt to form an airtight seal. For example, in some such closure
mechanisms, one closure
element has a sealing member spaced between two in-turned hooks and the other
closure
element has a channel defined by and between two out-turned hooks. The sealing
member
abuts against inside surfaces of the out-turned hooks to form a seal
therewith.
[0007] In other closure mechanisms, each closure element has a sealing member
disposed
between two interlocking members. The sealing members press against each other
when the
interlocking members are appropriately interlocked to form the seal. In one
closure
mechanism, for example, one closure element has two spaced out-turned male
hooks that
interlock with two complementary in-turned female hooks. A pressing rib spaced
between
the out-turned male hooks is wedged into a tapered channel defined by two
tightening walls
spaced between the in-turned female hooks. Each tightening wall also presses
against an
inner surface of the adjacent out-turned male hook.
[0008] In another closure mechanism, one closure element has two interlocking
bulbous
members spaced between two asymmetrical arrow-shaped members projecting from
one
base. The other closure element has three interlocking bulbous members spaced
between two
interlocking groove elements projecting from another base. The closure
elements resealably
mate with each asymmetrical arrow-shaped member interlocked with the opposing
groove
element and the two interlocking bulbous members on the one closure element
engaged in a
tight interfering fit between successive ones of the interlocking bulbous
members on the other
closure element. One of the closure elements has a backing member that may be
attached
directly to a pouch wall, and the other closure element has a backing member
that is attached
at only one end to another flange element that may be attached directly to a
pouch wall.
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SUMMARY OF THE INVENTION
[0009] According to one aspect of the invention, an airtight resealable
closure mechanism
having an elongate substantially constant profile extending between a first
end and a second
end includes a first closure element and a second closure element. The first
closure element
includes a first interlocking member, a second interlocking member, and a
first sealing
member, each protruding from a first base member, wherein the first sealing
member is
disposed between the first and second interlocking members. The second closure
element
includes a third interlocking member, a fourth interlocking member, and a
second sealing
member, each protruding from a second base member, wherein the second sealing
member
forms a tapered channel and is disposed between the third and fourth
interlocking members.
The first and second interlocking members are resealably interlocked with the
third and
fourth interlocking members, respectively. Each of the first and second
interlocking
members comprises a pair of arms forming a channel-shaped female interlocking
member,
and each of the third and fourth interlocking members comprises an arrow-
shaped male
interlocking member. The first sealing member is wedged into the tapered
channel of the
second sealing member, whereby an airtight seal is formed. The first and
second sealing
members are spaced from each of the first, second, third, and fourth,
interlocking members.
[0010] According to another aspect of the invention, an airtight resealable
closure
mechanism having an elongate substantially constant profile extending between
a first end
and a second end includes a first closure element and a second closure
element. The first
closure element includes a first interlocking member, a second interlocking
member, and a
first rib having a bulbous head, each protruding from a first base member,
wherein the first
rib is disposed between the first and second interlocking members. The second
closure
element includes a third interlocking member, a fourth interlocking member,
and a first wall
spaced from a second wall to define a channel therebetween, each protruding
from a second
base member, wherein the channel has substantially parallel sides and is
disposed between
the third and fourth interlocking members. The first and second interlocking
members are
resealably interlocked with the third and fourth interlocking members,
respectively. Each of
the second and third interlocking members comprises a pair of arms forming a
channel-
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shaped female interlocking member, and each of the first and fourth
interlocking members
comprises an arrow-shaped male interlocking member. The first rib is wedged
into the
channel, whereby an airtight seal is formed. The first rib, the first wall,
and the second wall
are spaced from each of the first, second, third, and fourth, interlocking
members.
[0011] According to yet another aspect of the present invention, an airtight
resealable
closure mechanism having an elongate substantially constant profile extending
between a
first end and a second end includes a first closure element and a second
closure element. The
first closure element includes a rib disposed between a first arrow-shaped
male interlocking
member and a second arrow-shaped male interlocking member, each of the first
and second
interlocking members and the rib protruding from one side of a first base
member. The
second closure element includes first and second walls disposed between a
third arrow-
shaped male interlocking member and a fourth arrow-shaped male interlocking
member, each
of the third and fourth interlocking members and the first and second walls
protruding from
one side of a second base member. The first interlocking member is resealably
interlocked
with the third interlocking member and the second interlocking member is
resealably
interlocked with the fourth interlocking member. The rib is wedged against the
first and
second walls, whereby an airtight seal is formed between the rib and the first
and second
walls.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is an isometric view of a pouch and an airtight closure
mechanism
according to one aspect of the present invention;
[0013] FIG. 2 is a partial cross-sectional view along the line 2-2 of FIG. I
with portions
behind the plane of the cross-section omitted for clarity;
[0014] FIG. 3 is a partial cross-sectional view similar to the view of FIG. 2
of an airtight
resealable closure mechanism according to another embodiment;
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[0015] FIG. 4 is a partial cross-sectional view similar to the view of FIG. 2
of an airtight
resealable closure mechanism according to still another embodiment;
[0016] FIG. 5 is a partial cross-sectional view similar to the view of FIG. 2
of an airtight
resealable closure mechanism of yet another embodiment;
[0017] FIG. 6 is a partial cross-sectional view similar to the view of FIG. 2
of an airtight
resealable closure mechanism according to a further embodiment; and
[0018] FIG. 7 is a partial cross-sectional view similar to the view of FIG. 2
of an airtight
resealable closure mechanism of a still further embodiment.
[0019] Other aspects and advantages of the present invention will become
apparent upon
consideration of the following detailed description, wherein similar
structures have the same
reference numerals throughout.
DETAILED DESCRIPTION
[0020] As seen in FIGS. 1 and 2, a resealable pouch 10 includes a first
sidewall 12 and a
second sidewall 14 that are connected, such as by folding, heat seal, and/or
adhesive, along
three peripheral edges 20a, 20b, and 20c to define a sealable interior space
16 therebetween,
and an opening 18 is defined along a top edge 20 where the first and second
sidewalls are not
connected so as to allow access to the interior space. A resealable elongate
closure
mechanism 22 extends along the first and second sidewalls 12, 14 near the
opening 18
between the peripheral edge 20a and the peripheral edge 20c of the pouch 10 to
allow the
opening to be repeatedly sealed and unsealed, thereby closing and opening,
respectively, the
opening.
[0021] When occluded, the closure mechanism 22 provides an air-tight seal such
that a
vacuum may be maintained in the pouch interior 16 for a desired period of
time, such as days,
months, or years, when the closure mechanism is sealed fully across the
opening 18. In one
embodiment, the pouch 10 may include a second opening 18a through one of the
sidewalls
12, 14 covered by a valve 28, such as a check or one-way valve, to allow air
to be evacuated
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from the pouch interior 16 and maintain a vacuum when the closure mechanism 22
has been
sealed. As shown in FIG. 1, the valve 28 may be disposed on the first sidewall
12 spaced
from the closure mechanism 22. The valve 28 provides a fluid path with fluid
communication between the pouch interior 16 and an exterior 118 of the pouch.
Illustrative
valves useful in the present invention include those disclosed in, for
example, Newrones et al.
U.S. Patent application publication No. 2006/0228057.
[0022] Although not shown, in some embodiments an evacuation pump or device
may be
used to evacuate fluid from the pouch 10 through., for example, the valve 28
disposed in one
of the sidewalls 12, 14, or in or through the closure mechanism 22 or in one
of the peripheral
edges 20a-20c of the pouch.
[0023] The pouch 10 may include relief on or along an interior surface of one
or both of
the first and second sidewalls 12, 14 to provide air flow channels 30 between
the sidewalls
when a vacuum is being drawn through the check valve 28. In this manner, the
pouch 10
provides a complete evacuable system within which food, for example, may be
stored in a
reusable vacuum pouch. One or both sidewalls, such as the second sidewall 14,
may also be
embossed or otherwise textured with a pattern, such as a diamond pattern, on
one or both
surfaces spaced between the bottom edge 20b and the closure mechanism 22 and
including a
smooth area adjacent the bottom edge and the top edge 20, or a separate
textured and
embossed patterned wall may be used to provide additional flow channels (not
shown) within
the pouch interior 16. Illustrative flow channels useful in the present
invention include those
disclosed in Zimmerman et al. U.S. Patent Application Publication No.
2005/0286808 and
Tilman et al. U.S. Patent Application Publication No 2006/0048483.
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[0024] As seen in FIG. 2, the closure mechanism 22 includes an interlocking
closure
element 32 that releasably interlocks and seals with an opposing interlocking
closure element
34. Each interlocking closure element 32, 34 has a substantially constant
elongate cross-
sectional profile that extends longitudinally between the peripheral edge 20c
and the
peripheral edge 20a of the pouch 10 to form a continuous seal therealong when
fully
interlocked with the opposing closure element. In one embodiment, closure
element 32 is
disposed along the first sidewall 12 and the closure element 34 is disposed
along the second
sidewall 14 opposite the first closure element so as to resealably interlock
along an entire
length thereof.
[0025] The interlocking closure element 34 has an elongate closure profile
including a
sealing section spaced between two interlocking members 36, 38, each
projecting from a
common side of a base member 40. In one embodiment, the interlocking member 36
has an
arrow-shaped male interlocking profile, and the interlocking member 38 has a
channel-
shaped female interlocking profile. The arrow-shaped male interlocking profile
36 includes a
shaft extending outwardly from the base member 40 and a symmetrical head with
barbs
extending from opposite sides of a distal end of the shaft spaced from the
base member. The
channel-shaped female interlocking profile 38 includes two spaced arms
extending from the
backing member 40, each arm having an in-turned hook at a distal end thereof,
to form a
channel therebetween. The sealing section of the closure element 34 includes a
sealing wall
42 and a sealing wall 44 spaced apart and projecting outwardly from the base
member 40.
The sealing walls 42, 44 in one embodiment are tapered, having a tip that is
narrower than a
base, thereby forming a tapered generally V-shaped channel 46 therebetween. In
one
embodiment, the sealing walls 42, 44 and the male and female interlocking
profiles 36, 38 are
all approximately the same height from the base member 40.
[0026] The interlocking closure element 32 has an elongate second closure
profile
including a sealing section spaced between two interlocking members 48, 50,
each projecting
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from a common side of a backing member 52. In one embodiment, the interlocking
member
48 has a channel-shaped female interlocking profile, and the interlocking
member 50 has an
arrow-shaped male profile, complementary with the respective male and female
interlocking
profiles 36, 38, respectively, of the closure element 34. The sealing section
of the closure
element 32 includes at least one sealing rib that wedges into the tapered
channel 46 between
the opposing sealing walls 42, 44. In one embodiment, the sealing section
includes a first
sealing rib 54 disposed between a second sealing rib 56 and a third sealing
rib 58. Each
sealing rib 54, 56, 58 has a bulbous head 60, such as a cross member, spaced
from the base
52 proximate a distal end of a wall 62, which projects from the base 52. In
one embodiment,
each sealing rib 54, 56, 58 has a T-shaped cross-section. In other
embodiments, the bulbous
head 60 may have other shapes that project laterally from the wall 62, such as
rounded,
asymmetrical, slanted, or multiple projections, for example. The first and
second interlocking
closure elements 32, 34 may include closure profiles as described previously
herein.
However, the configuration and geometry of the closure elements 32, 34 and
closure profiles
as disclosed herein may vary.
[0027] In a further embodiment, one or both of the closure elements 32, 34 may
include
one or more textured portions, such as a bump or crosswise groove in one or
more of the
interlocking members 36, 38, 48, 50 in order to provide a tactile sensation,
such as a series of
clicks, as a user draws the fingers along the closure mechanism to seal the
closure elements
across the opening 18. In another embodiment, all of the interlocking members
36, 38, 48, 50
include textured portions along the length of the profile to provide tactile
and/or audible
sensations when closing the closure mechanism 22. Further, in some
embodiments, a sealing
material such as a polyolefin material or a caulking composition such as
silicone grease may
be disposed on or in the closure profiles or closure elements 32, 34 to fill
in any gaps or
spaces therein when occluded. The ends of the closure profiles or closure
elements 32, 34
may also be welded or sealed by ultrasonic vibrations as is known in the art.
Illustrative
interlocking profiles, closure elements, sealing materials, tactile or audible
closure elements,
and/or end seals useful in the present invention include those disclosed in,
for example,
Pawloski U.S. Patent No. 4,927,474, Dais et al. U.S. Patent Nos. 5,070,584,
5,478,228, and
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6,021,557. Tomic et al. U.S. Patent No. 5,655,273, Sprehe U.S. Patent No.
6,954.969, Kasai
et at. U.S. Patent No. 5,689,866, Ausnit U.S. Patent No. 6,185,796, Wright et
al. U.S. Patent
No. 7,041,249, Pawloski et al. U.S. Patent No. 7,137,736, Anderson U.S. Patent
Application
Publication No. 2004/009 1 1 79, Pawloski U.S. Patent Application Publication
No. 2004/0234172, Tilman et al. U.S. Patent Application Publication No.
2006/0048483, and
Anzini et al. U.S. Patent Application Publication Nos. 2006/0093242 and
2006/0111226.
Other interlocking profiles and closure elements useful in the present
invention include those
disclosed in, for example, U.S. Patent No. 7,784,160. It is further
appreciated that the
closure profiles or closure elements disclosed herein may be operated by hand,
or a slider
(not shown) may be used to assist in occluding and de-occluding the closure
profiles and
closure elements.
[0028] In a sealed state, the male interlocking profile 50 is interlocked with
the female
interlocking profile 38, and the female interlocking profile 48 is interlocked
with the male
interlocking profile 36. The bulbous head 60 of the sealing rib 54 is wedged
tightly into the
tapered channel 46 against the sealing walls 42, 44. The sealing wall 42 is
wedged tightly
between and against the bulbous heads 60 of the sealing rib 54 and the sealing
rib 56, and the
sealing wall 44 is wedged tightly between and against the bulbous heads 60 of
the sealing rib
54 and the sealing rib 58. Preferably, the geometry of the sealing walls 42,
44 and the sealing
ribs 54, 56, 58 is such that, when the interlocking profiles 36, 38, 48, 50
are occluded
together in the sealed state, the distal ends of the sealing walls are spaced
from the backing
member 52 and the bulbous heads 60 are spaced from the backing member 40,
thereby
ensuring four air tight seals across the closure elements 32, 34 between the
interlocking
profiles 36, 48 and 38, 50. Further, the sealing sections are spaced from each
interlocking
member 36, 38, 48, 50, which provides a sealing section that forms an air
tight seal
independently of the interlocking members. Of course, more or fewer sealing
walls and
sealing ribs may be used in other embodiments to form more or fewer air tight
seals across
the closure elements.
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[0029] In order to develop differential opening and closing forces, one of the
closure
elements may be secured continuously to the respective sidewall along the
entire profile of
the base member, and the other closure element may be secured partially to the
respective
sidewall along only a portion of the profile. For example, in one embodiment,
the closure
element 34 is connected with the second sidewall 14 continuously between the
interlocking
member 36 and the interlocking member 38. The closure element 32 is connected
with the
first sidewall 12 continuously between the interlocking member 48 and an
interior side of the
sealing rib 58, and an interior end of the closure element 32 is unconnected
with the first
sidewall 12 between the interior end of the base 52 and the interior side of
the sealing rib 58.
In this manner, differential opening and closing forces may be developed
because the interior
end and interlocking profile 50 of the base 52 of at least the closure element
32 is allowed to
hinge away from the first sidewall 12, thereby minimizing an opening force
caused by the
contents pushing outwardly against the first and second sidewalls 12, 14. In
other
embodiments, the interior end of either or both closure elements 32, 34 may be
unconnected
with the respective sidewall 12 or 14, or the interior end of both closure
elements may be
connected with the respective sidewall.
[0030] The closure elements 32, 34 may be connected with the respective first
and second
sidewalls 12, 14 by many means, such as with adhesives or heat or ultrasonic
welding. In one
embodiment, the closure elements 32, 34 are connected with the respective
sidewalls 12, 14
using an intermediate layer 64 of connecting material, such as thermoplastic
weld material,
disposed between and connecting the base member 40, 52 of the closure element
with the
respective sidewall 14, 12. In this embodiment, a hot layer of thermoplastic
weld material 64
applied between each closure element 32, 34 and the respective sidewall 12, 14
melts and
attaches to both the sidewall and the base member, thereby forming a
thermoplastic weld
therebetween, which in some embodiments may provide a good continuous air
tight seal
between each sidewall and the respective closure element.
[0031] In one embodiment, the top edge 20 of one or both of the first and
second
sidewalls extends upwardly beyond an exterior end of the respective closure
element 32, 34.
One or more protuberances, for example, grip ridges 66, project from an
interior side of one
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or both of the sidewalls 12, 14 between the top edge 20 and the respective
closure element
32, 34 to provide additional finger traction in a convenient area for a user
to grip for opening
the closure mechanism 22.
[0032] In one embodiment, the first and second sidewalls 12, 14 and/or the
closure
mechanism 22 are formed from thermoplastic resins by known extrusion methods.
For
example, the sidewalls 12, 14 may be independently extruded of thermoplastic
material as a
single continuous or multi-ply web, and the closure mechanism 22 may be
extruded of the
same or different thermoplastic material(s) separately as continuous lengths
or strands.
Illustrative thermoplastic materials include polypropylene (PP), polyethylene
(PE),
metallocene-polyethylene (mPE), low density polyethylene (LDPE), linear low
density
polyethylene (LLDPE), ultra low density polyethylene (ULDPE), biaxially-
oriented
polyethylene terephthalate (BPET), high density polyethylene (HDPE),
polyethylene
terephthalate (PET), among other polyolefin plastomers and combinations and
blends thereof.
Further, inner surfaces of the respective sidewalls 12, 14 or a portion or
area thereof may, for
example, be composed of a polyolefin plastomer such as an AFFINITYTM resin
manufactured
by Dow Plastics. Such portions or areas include, for example, the area of one
or both of the
sidewalls 12, 14 proximate and parallel to the closure mechanism 22 to provide
an additional
cohesive seal between the sidewalls when the pouch 10 is evacuated of fluid.
One or more of
the sidewalls 12, 14 in other embodiments may also be formed of air-
impermeable film. An
example of an air-impermeable film includes a film having one or more barrier
layers, such
as an ethylene-vinyl alcohol copolymer (EVOH) ply or a nylon ply, disposed
between or on
one or more of the plies of the sidewalls 12, 14. The barrier layer may be,
for example,
adhesively secured between the PP and/or LDPE plies to provide a multilayer
film. Other
additives such as colorants, slip agents, and antioxidants, including for
example talc,
oleamide or hydroxyl hydrocinnamate may also be added as desired. In another
embodiment,
the closure mechanism 22 may be extruded primarily of molten PE with various
amounts of
slip component, colorant, and talc additives in a separate process. The fully
formed closure
mechanism 22 may be attached to the pouch body using a strip of molten
thermoplastic weld
material, or by an adhesive known by those skilled in the art, for example.
Other
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thermoplastic resins and air-impermeable films useful in the present invention
include those
disclosed in, for example, Tilman et al. U.S. Patent application publication
No 2006/0048483.
[0033] The fully formed closure elements 32, 34 may be attached along opposite
edges of
one side of the web by placing or extruding a strip of molten thermoplastic
weld material 64
onto the web along or adjacent to each edge of the web and immediately placing
a closure
element 32, 34 onto each strip of molten thermoplastic weld material. The
thermoplastic
weld material 64 may then be allowed to cool, the web folded together between
the opposite
edges to place the closure elements 32, 34 in opposing resealable relation,
and the web
severed transverse to the web direction into discrete pouches, in a manner
well known in the
art, to form the pouch 10. According to another embodiment, the web,
intermediate layer of
connecting material 64, and the closure elements 32, 34 may be extruded
together
simultaneously, and subsequently cooled, folded, and cut. If used, the check
valve 28 may be
formed on and/or attached to the web prior to folding or after folding.
[0034] The resealable pouch described herein can be made by various techniques
known
to those skilled in the art including those described in, for example, Geiger,
et al., U.S. Patent
No. 4,755, 248. Other useful techniques to make a resealable pouch include
those described
in, for example, Zieke et al., U. S. Patent No. 4,741,789. Additional
techniques to make a
resealable pouch include those described in, for example, Porchia et al., U.
S. Patent No.
5,012,561. Additional examples of making a resealable pouch as described
herein include,
for example, a cast post applied process, a cast integral process, and/or a
blown process.
[0035] Of course, various details shown in FIGS. I and 2 may be modified
within the
spirit of the present invention. For example, the specific orientation of the
closure elements
32, 34 with respect to the interior 16 may be altered from the orientation
shown in the
drawings, such that, for example, the male interlocking profile 36 and the
female interlocking
profile 48 may be disposed on the interior side 16 of the sealing sections. In
addition, the
location and/or use of the check valve 28 and the air flow channels 30 may be
modified as
desired.
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[0036] Referring to FIG. 3, another embodiment of an airtight closure
mechanism 122
includes closure elements 132 and 134, which are similar to the closure
elements 32, 34, but
with the following differences. The closure element 132 includes the sealing
ribs 54, 56, 58
spaced between the interlocking members 38 and 48 projecting from the interior
side of the
base member 52. Further, the closure element 134 includes the sealing walls
42, 44 spaced
between the interlocking members 36 and 50 projecting from the interior side
of the base
member 40. Spacing the sealing sections comprising the ribs 54, 56, 58 and the
walls 42, 44
from the interlocking members 36, 38, 48, 50 may generally provide a high
integrity seal that
is independent of the interlocking sections. Each interlocking member 36, 50
has an arrow-
shaped male interlocking profile, and each interlocking member 38, 48 has a
channel-shaped
female profile including a pair of arms 70, 72 that interlockingly engage the
opposing
interlocking member 36 or 50. Disposing both of the interlocking members
having a female
profile 38, 48 on a common closure element, for example, 132, and disposing
both of the
male interlocking members 36, 50 on an opposing common closure element, for
example,
134, may generally contribute to ease of manufacture of the closure elements.
[0037] Each closure element 132 and 134 is attached by an intermediate layer
64 to the
respective first or second sidewall 12 or 14 so as to create differential
opening force in a
similar manner as described previously herein. For example, the closure
element 132 is fully
attached to the second sidewall 14 with the intermediate layer 64 extending
completely
between the interlocking members 38 and 48, whereas the closure element 134 is
only
partially attached to the first sidewall 12 such that the interlocking member
50 and the sealing
rib 58 may deflect away from the first sidewall and the interlocking member 36
and sealing
ribs 54 and 56 are not able to deflect away from the first sidewall. The
remaining features of
the closure mechanism 122 are substantially similar to the closure mechanism
22 as
previously described herein. In another embodiment, the closure element 132
may be
attached to the first sidewall 12 and the closure element 134 may be attached
to the second
sidewall 14.
[0038] Referring now to FIG. 4, a further embodiment of an airtight closure
mechanism
222 includes closure elements 232 and 234, which are similar to the closure
elements 132 and
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134, respectively, but with the following differences. The closure element 232
includes
sealing ribs 54, 56, 58 spaced between interlocking members 36 and 38
projecting from the
interior side of the base member 52. Further, the closure element 234 includes
sealing walls
42, 44 spaced between interlocking members 48 and 50 projecting from the
interior side of
the base member 40. The bulbous heads 60 on the sealing ribs 54, 56, 58 are
arrow-shaped.
The sealing walls 42, 44 have substantially parallel facing inner surfaces 74,
76, respectively,
thereby defining an un-tapered channel 246 therebetween. The arrow-shaped
bulbous heads
60 of the sealing ribs 54, 56, 58 may generally provide a high integrity seal
requiring a
smaller closing force to engage than the T-shaped bulbous heads of the
embodiments
described previously herein. Each closure element 232, 234 is attached to the
respective first
or second sidewall 12, 14 by an intermediate layer 64 so as to create a
differential opening
force in a similar manner as previously described herein. All other features
of the closure
mechanism 222 are substantially similar to the closure mechanism 122 as
previously
described herein. In another embodiment, the closure element 232 may be
attached to the
second sidewall 14 and the closure element 234 may be attached to the first
sidewall 12.
[0039] Referring now to FIG. 5, yet another embodiment of an airtight closure
mechanism 322 includes closure elements 332 and 334, which are similar to the
closure
elements 232 and 234, respectively, but with the following differences. The
closure element
334 includes sealing walls 342, 344 spaced between the interlocking members 48
and 50
projecting from the interior side of the base member 40. Each sealing wall
342, 344 has a
bulbous head 78 spaced from the base member 40 proximate a distal end of a
wall 80, which
projects from the base 40. In one embodiment, the wall 80 has substantially
parallel sides
and the bulbous head 78 is generally arrow-shaped. In other embodiments, the
walls 80 may
be tapered and the bulbous heads 78 may have other shapes that project
laterally from the
wall 80, such as rounded, asymmetrical, slanted, or having multiple
projections. The sealing
walls 342, 344 define a channel 346 therebetween, wherein the channel 346 may
be tapered
or may have substantially parallel opposing side surfaces 374, 376. The
addition of the
bulbous heads 78 to the sealing walls 342, 344 may generally enhance the
likelihood of a
high integrity seal when engaged with the arrow-shaped bulbous heads 60 of the
sealing ribs
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54, 56, 58. The bulbous heads 78 may also provide an additional interlock
between the
closure elements 332, 334 to supplement the interlocking strength of the
interlocking
members 36, 38, 48, 50. Each closure element 332, 334 is attached to the
respective first or
second sidewall 12, 14 by an intermediate layer 64 so as to create a
differential opening force
in a similar manner as previously described herein. All other features of the
closure
mechanism 322 are substantially similar to the closure mechanism 222 as
previously
described herein. In another embodiment, the closure element 332 may be
attached to the
second sidewall 14 and the closure element 334 may be attached to the first
sidewall 12.
[0040] Referring now to FIG. 6, a still further embodiment of an airtight
closure
mechanism 422 includes closure elements 432 and 434, which are similar to the
closure
elements 332 and 334, respectively, but with the following differences. The
sealing sections
of the closure elements 432 and 434 are immediately adjacent the interlocking
sections. The
closure element 434 includes the sealing walls 342, 344 disposed between
interlocking
members 82 and 84 projecting from the interior side of the base member 40.
Further, the
closure element 432 includes the sealing rib 54 disposed between interlocking
members 86
and 88 projecting from the interior side of the base member 52. Each of the
interlocking
members 82, 84, 86, 88 has a male interlocking profile, which in one
embodiment includes
two barbs projecting from opposite sides of a shaft forming an arrow shape.
The interlocking
member 82 interlocks with the interlocking member 86, and the interlocking
member 84
interlocks with the interlocking member 88. A barb 90 extending from a side
facing the
sealing section of a distal end of the shaft of each male interlocking member
82, 84 engages
and interlocks with a barb 92 extending from a side facing away from the
sealing section of a
distal end of the shaft of each corresponding male interlocking profile member
86, 88.
Further, a barb 94 extending from a side facing the sealing section of the
distal end of the
shaft of each male interlocking member 86, 88 makes contact with each sealing
wall 342,
344, respectively. Providing this embodiment with all male interlocking
members 82, 84, 86,
88 may generally provide for ease of manufacture by requiring extrusion of
only male
profiles. Further, disposing the interlocking members 82, 84, 86, 88
immediately adjacent to
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the sealing sections of the closure elements 432 and 434 may provide a closure
mechanism
422 that is more rigid overall and thereby less resistant to deformation.
[0041] Each closure element 432, 434 is attached to the respective first or
second
sidewall 12, 14 by an intermediate layer 64 so as to create a differential
opening force in a
similar manner as previously described herein. For example, the intermediate
layer 64
extends behind all the interlocking members 82, 84 and sealing walls 342, 344
on the closure
element 434, and the intermediate layer extends behind only the sealing rib
54, the
interlocking member 86, and an upper portion of the base member 52 on the
closure element
432. Other portions of the closure mechanism 422 shown in FIG. 6 are
substantially similar
to the corresponding portions of the closure mechanism 322 as previously
described herein.
In another embodiment, the closure element 432 may be attached to the second
sidewall 14
and the closure element 434 may be attached to the first sidewall 12.
[0042] Referring now to FIG. 7, yet a further embodiment of an airtight
closure
mechanism 522 includes closure elements 532 and 534, which are similar to the
closure
elements 432 and 434, respectively, but with the following differences. The
closure element
534 includes sealing walls 542, 544 disposed between the interlocking members
82 and 84
projecting from the interior side of the base member 40. In one embodiment,
the sealing
walls 542, 544 have substantially parallel opposing sides that define an un-
tapered channel
546 therebetween, similar to the same features in the embodiment of FIG. 4. In
another
embodiment, the sealing walls 542, 544 have tapered opposing sides that define
a tapered
channel 546 therebetween, which is narrower near the base 40 and wider at a
distal end of the
sealing walls. The barb 94 extending from the side facing the sealing section
of the distal end
of the shaft of each male interlocking member 86, 88 contacts each sealing
wall 542, 544,
respectively. In one embodiment, the side of each sealing wall 542, 544 is
tapered toward the
distal end, which causes the sealing wall to wedge against the respective barb
94 when the
closure elements 532, 534 are interlocked together. Disposing the interlocking
members 86,
88 so that occlusion of the closure mechanism 522 forces the interlocking
members 86 and 88
inwardly against walls 542 and 544, respectively, may provide a closure
mechanism 522
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having a high integrity seal that is more rigid overall compared to
embodiments having
sealing sections spaced from interlocking sections.
[0043] Each closure element 532, 534 is attached to the respective first or
second
sidewall 12, 14 by an intermediate layer 64 so as to create a differential
opening force in a
similar manner as previously described herein. Other portions of the closure
mechanism 522
are substantially similar to the corresponding portions of the closure
mechanism 422 as
previously described herein. In another embodiment, the closure element 532
may be
attached to the second sidewall 14 and the closure element 534 may be attached
to the first
sidewall 12.
[0044] In further embodiments, more or fewer sealing walls and sealing ribs
may be used
in each embodiment described herein in order to form more or fewer air tight
seals across the
closure elements. Although various specific embodiments have been shown and
described
herein, this specification explicitly includes all possible permutations of
combinations of the
features, structures, and components of all the embodiments shown and
described.
INDUSTRIAL APPLICABILITY
[0045] An airtight resealable closure mechanism for a pouch is presented that
may be
used to pack and store perishable items contained therein in an air-free or
vacuum
environment. The closure mechanism includes a sealing section that may be
separate from an
interlocking section and may therefore provide a more secure air tight seal.
Clearly, many
other and varied uses of the pouch and closure mechanism disclosed herein are
also possible.
[0046] Numerous modifications to the present invention will be apparent to
those skilled
in the art in view of the foregoing description. Accordingly, this description
is to be
construed as illustrative only and is presented for the purpose of enabling
those skilled in the
art to make and use the invention and to teach the best mode of carrying out
same. The
exclusive rights to all modifications which come within the scope of the
appended claims are
reserved.
