Note: Descriptions are shown in the official language in which they were submitted.
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VALVE ELEMENT
FIELD OF THE INVENTION
[0001] The invention relates generally to valve elements and more particularly
to multi-ply,
one-way valve elements adapted for use with air and similar gasses. The
invention fmds
particular applicability in the field of flexible storage bags used for
storing food items.
BACKGROUND OF THE INVENTION
[0002] One type of one-way valve element commonly used with containers to
store coffee
beans is a generally planar structure constructed from two or more plies or
layers of flexible,
thermoplastic film. A first layer or base layer has an aperture disposed
there=through while a
second layer or top layer is stretched over and joined to the base layer to
normally cover the
aperture. During evacuation, air is moved through the aperture and displaces
the flexible top
layer with respect to base layer thereby allowing the evacuating air to escape
to the environment.
After evacuation, the resilient top layer returns to its normal position
overlying and covering the
aperture.
[0003] In some embodiments, silicone oil may be applied between the layers to
assist in
sealing of the valve element. Silicone oils, though, demonstrate liquid-like
properties that allows
them to leak from the valve element to an adjacent surface. For this reason,
the silicone oil
cannot be applied during the manufacture of the valve and wound on a roll.
Thus, the silicone oil
is applied at the point of attachment of the valve element to the container.
BRIEF SUMMARY OF THE INVENTION
[0004] The invention provides a novel one-way valve element that can be used
for
evacuating flexible storage bags. The invention also provides a flexible
storage bag that employs
the novel valve element disclosed herein. The one-way valve element according
to the invention
is made from multiple plies or layers including a base layer having an
aperture disposed through
it and a top layer overlying and joined to the base layer so as to cover the
aperture. Also, the
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base layer and top layer are further joined so as to provide an alternately
expandable and
collapsible channel between the aperture and an exit point on the valve
element that
communicates with the surrounding environment.
[0005] In use, the valve element is attached to the flexible sidewall of a
storage bag such that
the aperture aligns with a hole disposed through the sidewall, thereby
establishing
communication between the valve element and the interior volume. To maintain
the sealed
integrity of the interior volume, in the valve element's normal condition, the
top layer is
positioned over the base layer thereby collapsing the channel and
simultaneously covering the
aperture. During evacuation, air from the interior volume passes through the
aperture thus
displacing the top tayer with respect to the base layer and thereby expanding
the channel. Air
then passes via the channel to the exit point on the valve element to escape
to the environment.
To assist in forming the seal created between the base layer and the top layer
when the channel is
in its normally collapsed state, the valve element includes a senii-rigid
sealant material located in
the channel.
[0006] An advantage of the invention is that the semi-rigid material is less
susceptible to
displacement within or leaking from the valve element during evacuation.
Another advantage is
that the semi-rigid material can be applied during manufacture of the valve
element thereby
eliminating the step of applying silicone oil during construction of the bag.
These and other
advantages and features of the invention will become apparent from the
detailed description and
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Figure 1 is a perspective view of a flexible bag having attached to the
sidewall and
communicating with the interior volume a one-way valve element designed in
accordance with
the teachings of the invention.
[0008] Figure 2 is an exploded view of the one-way valve element of Figure 1
illustrated in
relationship to the flexible bag.
[0009] Figure 3 is a cross-sectional view of the one-way valve element taken
along line A-A
of Figure 1 and illustrating the channel in the normally collapsed
configuration.
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[0010] Figure 4 is a cross-sectional view of the one-way valve element taken
along line A-A
of Figure 1 and illustrating the channel in the expanded configuration.
[0011] Figure 5 is an exploded view of another embodiment of a valve element.
[0012] Figure 6 is a cross-sectional view of the valve element of Figure 5 and
illustrating the
channel in the normally collapsed configuration.
[0013] Figure 7 is a cross-sectional view of the valve element of Figure 5 and
illustrating the
channel in the expanded configuration.
[0014] Figure 8 is a perspective view of another embodiment of a valve
element.
[0015] Figure 9 is a perspective view of the opposite side of the valve
element shown in
Figure 8.
[00161. Figure 10 is cross-sectional view of the valve element shown in Figure
8.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0017] Now referring to the drawings, wherein like reference numbers refer to
like elements,
there is illustrated in FIG. 1 a storage bag 100 for storing items such as
food stuffs. In the
illustrated embodiment, the storage bag 100 is made from a first sidewall 102
and an opposing
second sidewall 104 overlying the first side wall to provide an interior
volume 106 therebetween.
The first and second sidewalls 102, 104 are joined along a first side edge
110, a parallel or non-
parallel second side edge 112, and a closed bottom edge 114 that extends
between the first and
second side edges. The first and/or second sidewalls 102, 104 may be made from
a flexible or
pliable thermoplastic material formed or drawn into a smooth, thin walled
sheet. Examples of
suitable thermoplastic materials include high density polyethylene (HDPE), low
density
polyethylene (LDPE), polypropylene (PP), ethylene vinyl acetate (EVA), nylon,
polyester,
polyamide, ethylene vinyl alcohol, and can be formed in single or multiple
layers. The
thermoplastic material can be transparent, translucent, opaque, or tinted.
Furthermore, the
material used for the sidewalls can be a gas impermeable material. The
sidewalls 102, 104 can
be joined along the first and second side edges 110, 112 and bottom edge 114
by any suitable
process such as, for example, heat sealing.
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[0018] For accessing the interior volume 106, the top edges 120, 122 of the
first and second
sidewalls 102, 104 remain un-joined to define an opening 124. To seal the
opening 124, first and
second interlocking fastening strips 126, 128 can be attached to the interior
surfaces of the
respective first and second sidewalls 102, 104. The first and second fastening
strips 126, 128
extend generally between the first and second side edges 110, 112 parallel to
and spaced below
the top edges 120, 122. In other embodiments, the bag 100 can include a
movable slider
straddling the fastening strips 126, 128 to facilitate occluding and
deoccluding of the opening
124.
[0019] To evacuate the storage bag 100 of latent or entrapped air after the
opening has been
closed, a one-way valve element 130 designed in accordance with the teachings
of the invention
is provided. The valve element 130 is attached to the first flexible sidewall
102 and
communicates with the interior volume 106. In one embodiment, the one-way
valve element 130
is configured to open under an applied pressure differential thereby allowing
air from the interior
volume 106 to escape and to close after elimination or reduction of the
pressure differential
thereby preventing the ingress of environmental air into the interior volume.
To establish the
pressure differential, a vacuum device can be used. For example, as
illustrated in FIG. 1, the
vacuum device 132 is configured as a hand-held, electrically operated device
having a nozzle
134. When activated, the vacuum device draws air from the interior volume 106
through the
valve element 130. In other embodiments, the pressure differential can be
provided by applying
a compressive force to the flexible sidewalls 102, 104 thereby forcing air
from the internal
volume through the valve element.
[0020] Referring to FIG. 2, the multi-ply valve element 130 includes a base
layer 142 and a
corresponding top layer 144. The base layer and top layer can be made from any
suitable
material such as, for example, a flexible, transparent, thermoplastic film.
Additionally, the base
layer and the top layer can be made from the same or different materials. The
base layer 142 is
circular with an aperture 146 disposed through its center such that the base
layer appears annular
in shape. The top layer 144 is positioned over and secured to the base layer
142 so as to cover
the aperture 146. Moreover, the top layer 144 also corresponds in size and
shape to the base
layer 142 such that the two layers provide a circular periphery 148 for the
valve element. Of
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course, it will be readily recognized that in other embodiments the valve
element can have any
other suitable shape including any of various polygonal shapes.
[0021] To secure the top layer 144 to the base layer 142, in the embodiment
illustrated in
FIG. 2, two parallel strips of adhesive 150 are applied to the base layer
extending along either
side of the aperture 146. The un-adhered portions of the top and base layers
142, 144 are located
between the two adhesive strips 150. The un-adhered portions provide an
expandable and
collapsible channel 152 that extends from the aperture 146 to opposing exit
points at the
periphery 148 of the valve element 130. The valve element 130 is then adhered
by a ring of
adhesive 158 (indicated by phantom lines on the underside of the base layer
142) to the flexible
bag 100 so as to cover the hole 156 disposed through the first sidewall 102.
Once attached, the
aperture 146 should align with the hole 156. Of course, as will be readily
apparent to those of
slcill in the art, in other embodiments, other suitable joining methods
besides or in addition to
adhesive can be employed to secure together the base and top layers, and the
base layer to the
sidewall, for instance, heat sealing.
[0022] Referring to FIG. 3, to prevent air from the environment from entering
into the
interior volume 106, the channel 152 is normally in a collapsed condition with
the top layer
covering the aperture 146. During evacuation, air from the internal volume 106
will pass
through the hole 156 in the first sidewall 102 and through the aperture 146 in
the base layer 142.
This evacuating air partially displaces the top layer 144 from the base layer
142 and thereby
places the channel 152 into the expanded condition illustrated in FIG. 4. The
air can then pass
along the expanded channel 152 formed between the adhesive strips 150 to the
periphery of the
valve element and escapes to the environment. Once evacuation is completed,
the resilient top
layer 144 will return to its prior configuration covering and sealing the
aperture 146 and thereby
collapsing the channel 152.
[0023] In accordance with the invention, to facilitate the functioning of the
valve element, a
semi-rigid sealant material is included between the base layer and top layer.
More particularly,
referring to FIG. 2, the semi-rigid sealant material 160 can be applied onto
the base layer 142
between the parallel strips of adhesive 148. Furthermore, the semi-rigid
sealant material 160
may extend from proximate the aperture 146 to the exit points at the periphery
148.
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[0024] The semi-rigid sealant material may demonstrate rigid characteristics
that help it
generally retain its shape even when encountering displacement forces. Such a
material may be
freestanding and will not flow like a liquid. However, the semi-rigid sealant
material may also
retain some resilient or compressive properties to facilitate sealing between
the valve element
layers. By way of example, a gel can be employed as a suitable material for
the semi-rigid
sealant material. Examples of suitable gels include hydrocarbon gels such as
Versagel available
from Penreco, gel adhesive such as the material designated as 555-8808
available from National
Starch and Chemical Company, or the material designated as Lite Loc from
National Starch and
Chemical Company, petrolatums, and jellies. Typically, such gels include at
least one block
copolymer that will bind to a liquid such as a mineral oil thereby enabling
the oil to become
semi-rigid. Additionally, the semi-rigid sealant material can be a
thermoplastic elastomer such
as Dynaflex available from GLS Corporation. By way of another example, the
semi-rigid sealant
material may have a hardness, using the Shore 00 hardness scale, in the range
of 0 to 70 points.
The hardness may be in a second range of 30 to 70 points. In one embodiment,
hardness may be
60 points.
[0025] Referring to FIG. 3, when the channel 152 is in the normally collapsed
position, the
top layer 144 sealingly contacts the semi-rigid sealant material 160. Thus, as
will be appreciated
from FIG. 3, the presence of the semi-rigid sealant material 160 offsets the
gap that would
otherwise exist due to the thickness of the adhesive strips 150. During
evacuation, the flexible
top layer 144 displaces with respect to the semi-rigid sealant material 160 as
well as the base
layer 142 thereby providing the expanded channel 152. Due to its semi-rigid
characteristics and
attachment to the base layer 142, the semi-rigid sealant material 160 will
remain in place even as
the evacuating air passes across it. It should be appreciated that in other
embodiments, if the
semi-rigid material 160 demonstrates sufficient flexibility, it can also be
applied to and flex with
the top layer 144.
[0026] In addition to remaining in place during evacuation, another advantage
of the semi-
rigid sealant material is that the material may demonstrate a light tact
property. The light tact
property will facilitate the sealing contact between the semi-rigid sealant
material and the
displaceable layer, but still allow the channel to expand when a sufficient
evacuation force is
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applied. A fitrther advantage of employing the semi-rigid sealant material is
that it can be
applied to the base layer at about the same time that adhesive strips are
applied. The semi-rigid
characteristics will allow the sealant material to remain located between the
valve element layers
during subsequent processing of the valve element and the storage bag.
[0027] In another embodiment, the semi-rigid material may be used in a
flexible valve that
consists of only a top layer and is applied over the aperture in the sidewall.
FIG. 5 shows one
embodiment of a valve element with the top layer applied over the aperture.
The valve element
230 has a top layer 244. The valve element 230 does not have a base layer. The
sidewall 202
has an aperture 256. To secure the top layer 244 to the sidewall 202, two
parallel strips of
adhesive 250 may be applied to the top layer. The un-adhered portions of the
sidewall 202 and
top layer 244 are located between the two adhesive strips 250. The un-adhered
portions provide
an expandable and collapsible channel 252.
[0028] Referring to FIG. 6, to prevent air from the environment from entering
into the
interior volume 206, the channel 252 is normally in a collapsed condition with
the top layer
covering the aperture 256. During evacuation, air from the internal volume 206
will pass
through the hole 256 in the first sidewall 202. This evacuating air partially
displaces the top
layer 244 from the sidewall 202 and thereby places the channel 252 into the
expanded condition
illustrated in FIG. 7. The air can then pass along the expanded channel 252
formed between the
adhesive strips 250 to the periphery of the valve element and escapes in the
environment. Once
evacuation is completed the resilient top layer 244 will return to its prior
configuration covering
and sealing the aperture 256 and thereby collapsing the channel 252.
[0029] In accordance with the invention, to facilitate the functioning of the
valve element, a
semi-rigid sealant material is included between the sidewall and the top
layer. More particularly,
referring to FIG. 5, the semi-rigid sealant material 260 can be applied onto
the top layer 244
between the parallel strips of adhesive 250. Furthermore, the semi-rigid
sealant material 260
may extend from proximate the aperture 256 to the exit points at the periphery
248.
[0030] Referring to FIG. 6, when the channel 252 is in the normally collapsed
position, the
top layer 244 sealingly contacts the semi-rigid sealant material 260. Thus, as
will be appreciated
from FIG. 6, the presence of the semi-rigid sealant material 260 offsets the
gap that would
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otherwise exist due to the thickness of the adhesive strips 250. During
evacuation, the flexible
top layer 244 displaces with respect to the semi-rigid sealant material 260 as
well as the sidewall
202 thereby providing the expanded channel 252. Due to its semi-rigid
characteristics and
attachment to the top layer 244, the semi-rigid sealant material 260 will
remain in place even as
the evacuating air passes across it. It should be appreciated that in other
embodiments, the semi-
rigid materia1260 can be applied to the sidewa11102.
[0031] In an additional embodiment, the semi-rigid sealant material may be
used in a rigid
valve. Referring to FIGS. 8, 9, and 10, the one-way valve element 300 for use
with a storage
bag of the foregoing type can include a rigid valve body 310 that cooperates
with a movable disk
312 to open and close the valve element. The valve body 310 includes a
circular flange portion
314 extending between parallel first and second flange faces 320, 322.
Concentric to the flange
portion 314 and projecting from the second flange face 322 is a circular boss
portion 318 which
terminates in a planar boss face 324 that is parallel to the first and second
flange faces. The
circular boss portion 318 is smaller in diameter than the flange portion 314
so that the outermost
annular rim of the second flange face 322 remains exposed. The valve body 310
canbe made
from any suitable material such as a moldable thermoplastic material like
nylon, HDPE, high
impact polystyrene (HIPS), polycarbonates (PC), and the like. -
[0032] Disposed concentrically into the valve body 310 is a counter-bore 328.
The counter-
bore 328 extends from the first flange face 320 part way towards the boss face
324. The counter-
bore 328 defines a cylindrical bore wal1330. Because it extends only part way
toward the boss
face 324, the counter-bore 328 forms within the valve body 310 a preferably
planar valve seat
332. To establish fluid communication across the valve body 310, there is
disposed through the
valve seat 332 at least one aperture 334. In fact, in the illustrated
embodiment, a plurality of
apertures 334 are arranged concentrically and spaced inwardly from the
cylindrical bore wall
330.
[0033] To cooperatively accommodate the movable disk 312, the disk is inserted
into the
counter-bore 328. Accordingly, the disk 312 is preferably smaller in diameter
than the counter-
bore 328 and has a thickness as measured between a first disk face 340 and a
second disk face
342 that is substantially less than the length of the counter-bore 328 between
the first flange face
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320 and the valve seat 332. To retain the disk 312 within the counter-bore
328, there is formed
proximate to the first flange face 320 a plurality of radially inward
extending fingers 344. The
disk 312 can be made from any suitable material such as, for example, a
resilient elastomer.
[0034] Referring to FIG. 10, when the disk 312 within the counter-bore 328 is
moved
adjacent to the fingers 344, the valve element 300 is in its open
configuration allowing air to
communicate between the first flange face 320 and the boss face 324. However,
when the disk
312 is adjacent the valve seat 332 thereby covering the apertures 334, the
valve element 300 is in
its closed configuration. To assist in sealing the disk 312 over the apertures
334, a semi-rigid
sealant material 360 can be applied to the valve seat 332. In other
embodiments, the sealant
material 360 may be applied to the disk 312, such as the disk face 342.
Furtherinore, a foam or
other resilient member may be placed in the counter-bore 328 to provide a
tight fit of the disk
312 and the valve seat 332 in the closed position.
[0035] To attach the valve element 600 to the first sidewall, referring to
FIG. 9, an adhesive
can be applied to the exposed annular rim portion of the second flange face
322. The valve
element 300 can then be placed adjacent the exterior surface of the first
sidewall with the boss
portion 318 being received through the hole disposed into the sidewall and
thereby pass into the
internal volume. Of course, in other embodiments, adhesive can be placed on
other portions of
the valve element, such as the first flange face, prior to attachment to the
sidewall.
[0036] All references, including publications, patent applications, and
patents, cited herein
are hereby incorporated by reference to the same extent as if each reference
were individually
and specifically indicated to be incorporated by reference and were set forth
in its entirety herein.
[0037] The use of the terms "a" and "an" and "the" and similar referents in
the context of
describing the invention (especially in the context of the following claims)
are to be construed to
cover both the singular and the plural, unless otherwise indicated herein or
clearly contradicted
by context. The terms "comprising," "having," "including," and "containing"
are to be
construed as open-ended terms (i.e., meaning "including, but not limited to,")
unless otherwise
noted. Recitation of ranges of values herein are merely intended to serve as a
shorthand method
of referring individually to each separate value falling within the range,
unless otherwise
indicated herein, and each separate value is incorporated into the
specification as if it were
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individually recited herein. All methods described herein can be performed in
any suitable order
unless otherwise indicated herein or otherwise clearly contradicted by
context. The use of any
and all examples, or exemplary language (e.g., "such as") provided herein, is
intended merely to
better illuminate the invention and does not pose a limitation on the scope of
the invention unless
otherwise claimed. No language in the specification should be construed as
indicating any non-
claimed element as essential to the practice of the invention.
[0038] Preferred embodiments of this invention are described herein, including
the best
mode known to the inventor(s) for carrying out the invention. Variations of
those preferred
embodiments may become apparent to those of ordinary skill in the art upon
reading the
foregoing description. The inventor(s) expect skilled artisans to employ such
variations as
appropriate, and the inventor(s) intend for the invention to be practiced
otherwise than as
specifically described herein. Accordingly, this invention includes all
modifications and
equivalents of the subject matter recited in the claims appended hereto as
pernlitted by applicable
law. Moreover, any combination of the above-described elements in all possible
variations
thereof is encompassed by the invention unless otherwise indicated herein or
otherwise clearly
contradicted by context.
