Note: Descriptions are shown in the official language in which they were submitted.
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VENTING CONTAINER
FIELD OF THE PRESENT INVENTION
[0001] The present invention relates generally to food storage containers.
More particularly,
the invention relates to a food storage container including a lid, a base and
a venting feature.
BACKGROUND OF THE INVENTION
[0002] Food storage containers are well known in the art. The noted containers
generally
include a lid that is selectively detachable from a bowl and are commonly
designed to provide a
variety of features, including being reusable, disposable, microwavable, and
the like.
[0003] Numerous types of bowl and lid assemblies and means for effecting
sealable
engagement of a lid on a bowl have been devised. Illustrative are the
containers and
engagement means disclosed in U.S. Pat. Nos. 6,170,696 and 6,868,980.
[0004] One problem associated with conventional, plastic, microwavable
containers stems
from the rapid temperature changes they must endure. The container must be
permitted to vent
during microwaving due to the high pressures that arise as moisture in the
container contents
vaporizes and gas temperatures increase. Thus, the container must be left open
to some degree
during microwaving. However, it is also desirable to keep the bowl covered as
much as
possible to prevent the contents from splattering the inside of the microwave.
[0005] A further problem often encountered with plastic containers is the poor
ability to
accommodate a desired amount of produce respiration while maintaining the
sealed integrity of
the container. As is well known in the art, providing adequate venting (or
breathing rate(s)) to
accommodate produce respiration can, and in most instances will, enhance
produce freshness.
[0006] Various methods and container designs have been employed to provide
adequate
venting of a container during and after microwaving, and to accommodate
produce respiration.
For example, the prior art is replete with containers that incorporate valves
or openable doors in
the container base or lid, which allow venting or increased gas exchange.
These executions
typically result in added cost and complexity in the manufacture of the
container. Additionally,
venting structure in the form of complex valves with moving parts is difficult
to design into a
thermoformed plastic part.
[0007] A common practice for venting a conventional container is to remove the
lid and
place it loosely over the container base to accommodate produce respiration
and, during
mi.crowaving, to allow air and steam to escape. Another common practice for
venting a
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container is to lift a small portion of the lid from engagement with the base
(i.e., "crack open"
the lid), such as at a corner region of a square or rectangular container.
Both of the noted
container venting practices will generally accommodate produce respiration.
However, in both
instances, the container is still subject to leaking, i.e., no longer lealc-
proof.
[0008] The noted container venting practices will usually permit sufficient
air and steam to
vent during microwaving because the increased pressure within the container
will tend to force
the container open, increasing any space between the lid and the bowl. There
is still a problem,
however, with the splattering of food that can occur through any unsealed
region between the
lid and base. Furthermore, once microwaving is complete, any steam present
within the
container will cool and the pressure in the container will drop significantly
as the pressure
differential no longer tends to open the container. The pressure drop creates
a vacuum that can
suck the lid into a sealed engagement with the base so that sufficient air may
not vent back into
the container to compensate for the pressure drop. This problem can be
aggravated by the
accumulation of steam or vapor, which can additionally form a vapor seal
between the lid and
bowl. The resulting vacuum can permanently damage the container.
[0009] It would thus be advantageous to provide a venting container lid having
effective,
easy to use venting means (i) that is adapted to effectuate sealable
engagement of the lid and a
container base in a first position and provide an effective air passage when
the venting means is
in a second position and (ii) can be readily manufactured via a conventional
thermoforming
process.
SUNIlVIARY OF THE INVENTION
[00010] In accordance with one embodiment of the invention, disclosed herein
is a reclosable
lid for a venting container, the container including a base having an inner
cavity and a side wall
that terrninates in a rim, the lid including a central panel and a peripheral
sealing lip that
surrounds the panel, the peripheral sealing lip having a generally inverted U-
shaped cross section
that defines a lid channel into which the container rim fits, the sealing lip
is provided with venting
means in the form of a flexible venting button that is adapted to transition
from a first position to
a second position upon application of an actuation force, the venting button
being further adapted
and positioned whereby when the container rim is positioned in the lid channel
and the venting
button is in the first position, sealed engagement of the lid to the container
is effectuated and
when the venting button is in the second position the respective sealing
surfaces of the lid and
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base are displaced relative to one another such that a venting air passage is
provided from the
container cavity to the container surroundings. The venting button is
preferably formed integral
with a surface of the lid channel and comprises an eversible dome including a
border portion that
surrounds a raised portion, the raised portion protruding from a plane defined
by the border
portion, the raised portion further including an apex that forms an outermost
protruding part of
the raised portion, the apex adapted to contact a surface of the second
closure portion when the
venting button is moved into the second position.
[00011] In another embodiment, the venting means comprises a second and
optionally a third
venting button, both of which may be selectively actuated along with actuation
of the first venting
button to provide an enhanced amount of venting through the closure region of
the container.
[00012] In accordance with another embodiment of the invention, there is
described a venting
container comprising a selectively detachable lid, the lid including a central
panel and peripheral
sealing lip that surrounds the panel, the peripheral sealing lip having a
generally inverted U-
shaped cross-section that defines a lid channel, the lip including a venting
boss; and a container
base having an inner cavity, the container base further having a side wall
that terminates in a
container rim, the container rim being adapted to be positioned in the lid
channel, the container
rim including a venting boss seat adapted to receive the venting boss when the
container rim is
positioned in the lip channel and the lid and base are in a first position,
whereby sealable
engagement of the lid and the base is effectuated, and whereby when the lid is
rotated relative to
the container to a second position, wherein the venting boss is disposed
distal from the venting
boss seat, and the container rim is repositioned and in the lip channel a
venting air passage is
provided from the container cavity to the container surroundings.
[00013] The present invention substantially reduces or eliminates the
disadvantages and
drawbacks associated with prior art container base and lid assemblies. As
discussed in detail
herein, the container designs of the invention include highly effective,
simple to operate venting
means that prevent splattering of the container contents during microwaving
and that also
accommodate produce respiration.
[00014] The features of the present invention will become apparent to one of
ordinary skill in
the art upon reading the detailed description, in conjunction with the
accompanying drawings,
provided herein.
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BRIEF DESCRIPTION OF THE DRAWINGS
[00015] Fig. 1 is a perspective view of a venting container including a lid
and a base in
accordance with one embodiment of the invention.
[00016] Fig. 2 is an exploded perspective view of the venting container shown
in Fig. 1.
[00017] Fig. 3 is a cross sectional view of the venting container taken along
the line and in the
direction of arrows 3-3 of Fig. 1 which illustrates a first lid venting button
in a first non-venting
position.
[00018] Fig. 4 is a cross sectional view of the venting container similar to
Fig. 3 which
illustrates the first lid venting button in a second venting position.
[00019] Fig. 5 is a side view of the venting container of Fig. 1 showing in
partial section the
actuation of the venting button in the second venting position.
[00020] Fig. 6 is a perspective view of another embodiment of the venting
container showing
a container lid with three venting buttons.
[00021] Fig. 7 is a perspective view of a venting container in accordance with
another
embodiment of the invention.
[00022] Fig. 8 is a perspective view of the base of the venting container of
Fig. 7.
[00023] Fig. 9 is a cross sectional view of the venting container taken along
line and in the
direction of arrows 9-9 of Fig. 7 which illustrates the lid in its first non-
venting orientation.
[00024] Fig. 10 is a cross sectional view similar to Fig. 9 which illustrates
the lid in its second
venting orientation.
[00025] Fig. 11 is a side view of the venting container of Fig. 7 showing in
partial section a
venting corner region when the lid is in its second venting orientation.
DETAILED DESCRIPTION OF THE 1NVENTION
[00026] Unless defined otherwise, all technical and scientific terms used
herein have the same
meaning as commonly understood by one having ordinary skill in the art to
which the invention
pertains.
[00027] Turning to the drawings, wherein like reference numerals refer to like
elements, a
first embodiment of the present invention is illustrated in Figures 1 and 2. A
container 10
includes a container base 20 and a flexible container lid 40. In the example
shown in the
Figures, the container 10 is depicted as substantially square with rounded
corners. In other
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v[{JG1\V= 'T14.//V
embodiments of the present invention, the container 100 has other shapes such
as rectangular,
circular, or elliptical.
[00028] The container base 20 has a bottom 22 and a sidewall 24 extending from
the
periphery of the bottom 22. At the termination of the sidewall 24 an outwardly
and
substantially horizontally extending denesting shoulder 26 is provided, which
merges into the
base of a closure portion 28. The closure portion 28 has a generally
horizontal rim surface 30
and a generally inverted U-shaped cross section. The bottom surface 22
provides a staclcing
recess (not shown) extending upwardly to a substantially horizontal central
panel surface (also
not shown).
[00029] The container lid 40 is adapted to sealingly engage the container base
20.
According to one einbodiment of the invention, container lid 40 generally
includes a central
panel 42 surrounded by a peripheral closure portion or sealing lip 44. The
central panel 42
optionally includes one or more stacking beads 43 that cooperate with the
stacking recess
provided in the bottom surface 22 of the base 20. The lid closure portion 44
includes four
corners 46 an optional gripping tab 48. The lid closure portion 44 of the lid
40 is adapted to
sealingly engage base closure portion 30. The lid closure portion 44 has a
horizontal rim
surface 50 disposed between inner and outer walls 58, 60 that together form a
generally
inverted U-shaped cross section that defines a lid channel. The lid includes
venting means
which comprises at least one venting button 52. In accordance with a preferred
embodiment of
the invention the venting button 52 is located along the horizontal rim
surface 50 and preferably
at a corner region and most preferably at corner region provided with gripping
tab 48. Locating
the venting button at one corner allows the other three corners of the lid to
remain sealed when
the container 10 is in a venting configuration, thereby providing the best-
vented seal possible.
In other embodiments, the venting button 52 may be located medial of the
corners 46 or located
along the inner or outer walls 58, 60 of the lid channel.
[00030] Referring now to Figs. 3 and 4 the closure portion 28 of the container
bottom 20
generally includes an inner wall 32 and an outer wall 34 and, as noted
previously, the closure
portion 44 of the container lid 40 includes inner wall 58 and an outer wall
60. As shown, inner
walls 32 and 58 are formed as mating under cuts such that when lid 40 is
secured to base 20, the
inner wall 32 provides an interference fit with the inner wall 58 of the lid
40. As such, the inner
walls 32 and 58 provide a first set of sealing surfaces. Outer walls 34 and 60
may also be
formed as mating undercuts to provide a second set of sealing surfaces to
provide a container
CA 02611747 2007-12-11
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having inside and outside continuous seal regions. Hence, the closure portion
or sealing lip 44
of the lid 40 acts as a sealing channel to receive the horizontal rim surface
30 of the closure
portion 28 of container base 20. Further details of the above-described
closure portions for the
lid and base are set forth in U.S. Patent 6,170,696 B1, which is incorporated
by reference herein
in its entirety. Although the closure design of the preferred embodiment is
described as liaving
both inside and outside sealing surfaces, it is understood that the venting
features of the present
invention may work equally well with other lrnown U-shaped closure
configurations such as
those generally U-shaped closure designs where the primary sealing contact is
generally limited
to the mating inner walls (or alternately mating outer walls) of the lid and
base closure portions
with the respective outer walls (or alternately inner walls) of the lid and
base closure portions
providing little or no contribution to forming an additional continuous
peripheral sealing zone.
For example, in the embodiment described, the respective outer walls 34 and 60
need not both
be formed as undercuts and either outer wall may be vertically oriented or
even slope outward
beyond vertical (i.e., opposite to undercut).
[00031] The base 20 and lid 40 can be made as thermoformed parts.
Alternatively, one or
both of these components could be made by other processes, including, for
example, blow
molding or injection molding. It should be noted, however, that those skilled
in the art
understand that minor structural modifications likely will occur if a process
other than
thermoforming is used.
[00032] As discussed briefly above, the venting means comprises at least one
flexible venting
button 52 that is disposed on the closure portion 44. More specifically, the
venting button 52 is
disposed on the horizontal rim surface 50, as shown in Figs. 3 and 4. The
venting button 52
includes a border portion 62 that surrounds a raised portion 64. The border
portion 62 is
formed integral with the horizontal rim surface 50. The raised portion 64 may
be formed as a
rounded or semi-spherical eversible dome protruding from the plane defined by
the border
portion 62. As a result of its rounded shape, the raised portion 64 includes
an apex 66 that
forms the outermost protruding part of the raised portion 64 and an inflection
region that
integrally connects the apex 66 to the border portion 62. Preferably, the
raised portion 64 is
about one-half the diameter of the border portion 62. In practice, the
eversible nature of the
raised domed portion 64 may be facilitated by material thinning at the
junction between the
border portion 62 and the raised portion 64. In accordance with an alternate
embodiment
wherein the lid is formed as an injection molded part, the thickness of the
eversible raised
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domed portion 64 is preferably less than about 50% of the thiclmess of
adjacent areas the lid as
taught in US 2004/0232036 Al at numbered paragraph 51, which is incorporated
herein by
reference.
[00033] The venting button 52 is designed and adapted to be moved between a
first, non-
venting position as shown in Fig. 3 and a second, venting position as shown in
Fig. 4-5. In the
first position of the venting button 52 (Fig. 3), the eversible raised portion
64 of the venting
button protrudes in a direction away from the horizontal rim surface 30 of the
bottom closure
portion 28. In this position, the inner walls 32 and 58 remain in sealing
contact when the lid 40
is engaged to the base 20. In the second position of the venting button (Figs.
4 and 5), the
raised portion 64 is inverted and faces towards the horizontal rim surface 30
of the bottom
closure portion 28. The apex 66 abuts the horizontal rim surface 30 such that
inner sealing wall
58 is displaced from sealing contact with inner wall 32 and outer wall 60 is
displaced relative to
outer wa1134 to provide a venting air passage denoted generally by Arrows A,
A' and B, B'. As
noted above, the respective outer walls 34 and 60 of the base and lid closure
portions need not
form a second set of sealing surfaces and could be arranged as vertical or
beyond vertical
seginents as desired.
[00034] The venting button 52 is adapted to remain in the first and second
positions after
placement thereof until an external (or actuation) force F, is applied to the
button 52. As will
be appreciated by one having ordinary skill in the art, the actuation force
will typically depend
on the size of the container closure and button 52, as well as the placement
of the button 52 on
the lid closure portion 44.
[00035] Preferably, the actuation force (Fõ) is in the range of approximately
0.25 -15.01bs.,
more preferably, in the range of approximately 0.5 -10.01bs., even more
preferably, in the
range of approximately 1.0 - 5.0 lbs. As will be appreciated by one having
ordinary skill in the
art, the noted actuation force is sufficient to maintain the button 52 in a
desired venting or non-
venting position while providing easy actuation therebetween.
[00036] According to the invention, the venting button 52 can comprise various
sizes,
depending on the size and shape of the container closure. In one embodiment
(i.e., closure size
ranges from approximately 0.3 - 0.6 in. proximate the button 52), the venting
button 52 is
substantially circular in shape and has a diameter in the range of
approximately 0.25 - 0.6 in.
In another embodiment, the diameter of the venting button 52 ranges from
approximately 0.35
- 0.55 in.
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[00037] As stated, the venting button 52 transitions from the first position
to the second
position a distance sufficient to provide an effective air passage at the
second position. The
actual transition distance will similarly depend on the size (e.g., horizontal
surface width) of the
rim surface 50 and venting button 52.
[00038] An exemplary venting mode of operation is as follows: a user merely
lifts the corner
46 of the lid 40 from the base 20 (if attaclied thereto) while applying the
noted actuation force
(denoted by Arrow Fv) to the venting button 52 to transition the eversible
raised domed portion
64 from the first, non-venting position (Fig. 3) to the second, venting
position (Fig. 4). When
the venting button 52 is moved into its second venting position, the apex 66
of eversible raised
domed portion 64 abuts rim surface 30 of the base closure portion 28 thereby
displacing or
raising the lid 40 proximate the button 52 a sufficient amount to (i)
facilitate produce
respiration and/or (ii) during microwaving, permit air and steam to vent from
the container and
permit sufficient air to vent back into the container 10 during cooling to
compensate for the
pressure drop.
[00039] Fig. 6 illustrates another embodiment of the present invention. The
container 110
consists of a container base 120 identical to container base 20 as shown in
Figs. 1-5 and a
container lid 140. The container lid 140 is substantially identical to the
container lid 40
described in Figs. 1-5 except that in addition to venting button 52 it
includes a second venting
button 152 and optionally a third venting button 252. Like the first venting
button 52, the
venting buttons 152 and 252 are preferably located at the corner regions 146
of the lid 140.
Operation of venting buttons 152 and 252 is identical to that as previously
described in
connection with Figs. 3-5. The venting buttons 52, 152, and 252 may be
selectively actuated to
provide a desired amount of venting.
[00040] Figs. 7 through 11 illustrate another embodiment of a venting
container of the present
invention. The container 310 includes a container base 320 and a flexible
container lid 340
sealingly engaged thereto. The container base 320, has a bottom 322 and a
sidewall 324
extending from the periphery of the bottom 322. At the termination of the
sidewal1324 an
outwardly and substantially horizontally extending denesting shoulder 326 is
provided, which
merges into the base of a closure portion 328. The closure portion 328 has a
generally
horizontal rim surface 330 and a generally inverted U-shaped cross section.
[00041] The container lid 340 generally includes a central pane1342 surrounded
by a
peripheral closure portion or sealing lip 344. The central panel 342
optionally includes one or
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more stacking beads 343 that cooperate with the stacking recess (not shown)
provided in the
bottom surface 322 of the base 320. The lid closure portion 344 includes four
corners 346 an
optional gripping tab 348. The lid closure portion 334 of the lid 340 is
adapted to sealingly
engage base closure portion 330. The lid closure portion 344 has a horizontal
rim surface 350
and a generally inverted U-shaped cross section that defines a lid channel.
[00042] As illustrated in Fig. 7, the lid 340 further includes venting means,
designated
generally at 372.
[00043] In a preferred embodiment, the venting means 372 comprises at least
one protrusion
or venting boss 374 that is disposed proximate the lid closure portion 344.
The venting boss
374 is disposed on the horizontal rim surface 350 and protrudes into the lid
channel as shown in
Figs. 9 and 10.
[00044] According to the invention, the venting boss 374 can similarly be
disposed at any
position on the lid closure portion 344. Preferably, for quadrilaterals the
venting boss 374 is
disposed proximate a lid corner 346. In a preferred embodiment of the
invention, the venting
boss 374 is disposed proximate corner 346, which, as illustrated in Figs. 7,
and 9-11 is also
proximate the gripping tab 348.
[00045] As illustrated in Figs. 8 and 9, the container bottom 320 includes a
venting boss seat
336 adapted to receive the venting boss 374 when the lid 340 and the base 320
are in an
engaged position and the lid 340 and, hence, venting boss 374 are oriented in
a first non-
venting position. When the lid 340 is rotated to or oriented in a second
venting position, the
venting boss 374 seats on the container horizontal rim surface 330, as
illustrated in Figs. 10 and
11, whereby the lid 340 is slightly raised proximate the boss 374 and
similarly provides a
venting air passage. In this second venting position, inner wal1358 of the lid
closure portion
344 is displaced and disengaged from sealing contact with inner wal1332 of the
base closure
portion 328 and outer wall 360 of the lid closure portion 344 is displaced
relative to outer wall
334 of the base closure portion 328 to provide a venting air passage denoted
generally by
Arrows O, O' and C, C.
[00046] According to the invention, the venting boss 374 can similarly
comprise various
sizes, depending on the size and shape of the container closure. hi a
preferred embodiment
(i.e., closure size in the range of approximately 0.3 - 0.6 in. proximate the
boss 374), the
venting boss 374 is substantially circular in shape and has a diameter in the
range of
approximately 0.25 - 0.6 in., more preferably, in the range of approximately
0.35 - 0.55 in.
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[00047] To place the container 310 in a venting orientation, a user merely
removes the lid 340
from the container base 320, rotates and places the lid 340 back on the
container base 320 in a
venting position as shown in Figs. 10 and 11. For a square container the lid
340 need only be
rotated by 90 to allow venting. For a rectangular container, the lid 340
requires a rotation of
180 to move to the venting position. In the noted venting position, the
venting boss 374
similarly raises a corner 346 of the lid 340, which (i) accommodates produce
respiration and/or
(ii), during microwaving, permits air and steain to vent from the container
and allows sufficient
air to vent baclc into the container during cooling to compensate.for the
pressure drop, while
substantially maintaining the sealed integrity (i.e., leak-proof) of the
container 310.
[00048] To place the container 310 back into the fully sealed non-venting
orientation, the user
merely removes and rotates the lid 340 to align the venting boss 374 with the
venting boss seat
336 and then depresses the lid onto the base to sealingly engage the lid
closure portion 344 with
the base closure portion 328.
[00049] The container can be reusable, but it can also be constructed cheaply
enough that
consumers see it as a disposable item, with replacement covers and bases
available separately
for retail sale. The base and the cover can be fabricated by thermoforming a
clarified
polypropylene homopolymer material. In another embodiment, the container may
be fabricated
by thermoforming a clarified random copolymer polypropylene material. Other
plastic
materials which would be suitable for fabricating the container by
thermoforming include PS
(polystyrene), CPET (crystalline polyethylene terephthalate), APET (amorphous
polyethylene
terephthalate), HDPE (high density polyethylene), PVC (polyvinyl chloride), PC
(polycarbonate), and foamed polypropylene. The material used can be generally
transparent to
allow a user to view the contents of the container.
[00050] The container may include a visual indication of closure between the
container cover
and the container base. The visual indication may be a color change in the
area where the cover
engages the base. In one embodiment, the closure portion on the cover may be a
first color and
the closure portion on the base may be a second color. When the closure
portions are engaged,
the first and second colors produce a third color which is visible to the user
to indicate that the
container is sealed.
[00051] The container may include a rough exterior surface to reduce slipping
and to improve
grasping by the user, especially if the user's hands are wet or greasy.
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[00052] The container may be divided to separate foods in the container. A
divider may be
integral with the container or may be a separate component. Either the base
only may include a
divider or both the base and the cover may each include a divider. The divider
located in the
cover may only partially engage the divider in the base so as to provide
splash protection, or it
may fully engage the divider in the base to provide varying degrees of inter-
compartmental leak
resistance.
[00053] The container may include a strip indicating the temperature of the
container and its
contents.
[00054] The gripping tab can include a relieved portion that provides less
interference contact
with the base during the removal or engagement of the cover while still
providing an adequate
closure portion to maintain proper sealin.g of the container. The relieved
portions of the
gripping tab permit venting by allowing a portion of the cover to be unsealed
from the base
while still maintaining a seal around the remaining perimeter of the
container. This feature is
useful in microwave cooking where the cover prevents food froin splattering
onto the inside
surface of the microwave while still allowing the container to vent. By using
the gripping tab,
less force is required to remove the cover from the base. This lower opening
force also reduces
the possibility of container failure from stress and fatigue. The lower
opening force can
improve the ability of the user to maintain control over the container
components while
removing the cover from the base and thus to reduce the possibility of
spilling the contents
stored in the container.
[00055] The use of the terms "a," "an," "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. 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 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 indicated.
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[00056] While the invention is described herein in connection with certain
preferred
embodiments, there is no intent to limit the present invention to those
embodiments. On the
contrary, it is recognized that various changes and modifications to the
described embodiments
will be apparent to those skilled in the art upon reading the foregoing
description, and that such
changes and modifications may be made without departing from the spirit and
scope of the
present invention. Skilled artisans may employ such variations as appropriate,
and the invention
may be practiced otherwise than as specifically described herein. Accordingly,
the intent is to
cover all alternatives, modifications, and equivalents included within the
spirit and scope of the
invention. 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.
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