U.S. patent application number 10/457285 was filed with the patent office on 2004-03-04 for food storage containers.
Invention is credited to Coronado, Juan Carlos, Gili, Sergi, Millan, Jose, Penaranda, Mariano, Rebordosa, Antonio, Vilalta, Montserrat.
Application Number | 20040040961 10/457285 |
Document ID | / |
Family ID | 31981873 |
Filed Date | 2004-03-04 |
United States Patent
Application |
20040040961 |
Kind Code |
A1 |
Vilalta, Montserrat ; et
al. |
March 4, 2004 |
Food storage containers
Abstract
A lid for a food storage container includes a lid defining a
vacuum sense opening and a vent opening extending through the lid
body. The lid also includes a releasable cover disposed over the
vent opening to impede air flow into the container through the vent
opening until the cover is released. The lid further includes a
pressure indicating dome defining a cavity therein, the dome in
hydraulic communication with the container through the vacuum sense
opening, the dome having a membrane that collapses toward the
vacuum sense opening in response to negative container
pressure.
Inventors: |
Vilalta, Montserrat;
(Barcelona, ES) ; Millan, Jose; (Barcelona,
ES) ; Coronado, Juan Carlos; (Barcelona, ES) ;
Penaranda, Mariano; (Barcelona, ES) ; Rebordosa,
Antonio; (Barcelona, ES) ; Gili, Sergi;
(Barcelona, ES) |
Correspondence
Address: |
FISH & RICHARDSON PC
225 FRANKLIN ST
BOSTON
MA
02110
US
|
Family ID: |
31981873 |
Appl. No.: |
10/457285 |
Filed: |
June 9, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10457285 |
Jun 9, 2003 |
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PCT/EP01/13148 |
Nov 14, 2001 |
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10457285 |
Jun 9, 2003 |
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PCT/EP01/13233 |
Nov 15, 2001 |
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10457285 |
Jun 9, 2003 |
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PCT/EP02/14693 |
Dec 21, 2002 |
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Current U.S.
Class: |
220/212 ;
220/203.16; 220/203.23 |
Current CPC
Class: |
B65D 79/0087 20200501;
B65D 51/1683 20130101; B65D 81/2038 20130101; B65D 79/02 20130101;
B65D 81/2015 20130101 |
Class at
Publication: |
220/212 ;
220/203.16; 220/203.23 |
International
Class: |
B65D 051/16; B65D
051/24 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 8, 2000 |
DE |
100 60 999.6 |
Dec 8, 2000 |
DE |
100 60 995.3 |
Jul 9, 2002 |
DE |
102 30 748.2 |
Claims
What is claimed is:
1. A lid for a food storage container, the lid comprising: a lid
body defining a vacuum sense opening and a vent opening extending
through the lid body; a releasable cover disposed over the vent
opening to impede air flow into the container through the vent
opening until the cover is released; a pressure indicating dome
defining a cavity therein, the dome in hydraulic communication with
the container through the vacuum sense opening, the dome comprising
a membrane that collapses toward the vacuum sense opening in
response to negative container pressure.
2. The lid of claim 1, further comprising a resilient layer in
contact with the membrane.
3. The lid of claim 2, wherein the resilient layer comprises a
spring sheet.
4. The lid of claim 2, wherein the resilient layer comprises an
elastomeric polymer.
5. The lid of claim 1, wherein the cover defines an indicator
opening, and wherein the membrane, under certain container pressure
conditions, extends through the indicator opening.
6. The lid of claim 1, wherein the membrane is formed of a plastic
resin.
7. The lid of claim 6, wherein the plastic resin is selected to
maintain dimensional stability of the membrane over a temperature
range between -40.degree. C. and 100.degree. C.
8. The lid of claim 1, further comprising a one-way valve.
9. The lid of claim 8, wherein the one-way valve comprises a
movable sealing tab.
10. The lid of claim 9, wherein the pressure indicating dome is
integrally connected with the sealing tab.
11. The lid of claim 1, wherein the cover is pivotably connected to
the lid body by a hinge.
12. The lid of claim 1, wherein the pressure indicating dome
comprises a spring.
13. The lid of claim 1, wherein the pressure indicating dome
comprises a resilient material.
14. A lid for a food storage container, the lid comprising: a lid
body defining a vent opening therethrough; a releasable cover
disposed over the vent opening to impede air flow into the
container through the vent opening until the cover is released, the
releasable cover defining an evacuation opening; a membrane that
covers the vent hole until the cover is released; and a driving
element connected to the membrane at one end and disposed within
the evacuation opening at another end.
15. The lid of claim 14, wherein the membrane comprises an
elastomeric plastic.
16. The lid of claim 14, wherein the membrane is a one-way
valve.
17. The lid of claim 14, wherein the driving element defines a
rim.
18. The lid of claim 14, wherein the driving element is integrally
connected to the membrane.
19. The lid of claim 14, wherein the cover defines a surface
extending about the evacuation opening and adapted to receive a
sealing lip of a vacuum pump.
20. The lid of claim 14, wherein the lid body comprises a plastic
resin selected to maintain dimensional stability of the membrane
over a temperature range of between -40.degree. C. and 100.degree.
C.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of PCT
applications PCT/EP01/13148, filed on Nov. 14, 2001,
PCT/EP01/13233, filed on Nov. 15, 2001, and PCT/EP02/14693, filed
on Dec. 21, 2002, and claims priority under 35 U.S.C. .sctn. 119(a)
from German patent applications DE 100 60 999.6 and DE 100 60
995.3, both filed on Dec. 8, 2000, and from German patent
application DE 102 30 748, filed on Jul. 9, 2002.
TECHNICAL FIELD
[0002] This invention relates to sealable food storage
containers.
BACKGROUND
[0003] Food storage can be improved by keeping food in a container
under vacuum. Keeping the food in a container under vacuum helps to
protect the food from certain microorganisms and pests, as well as
mold and fungus growth. Furthermore, it helps prevent the food from
oxidizing, thereby maintaining the moisture level and aroma of the
food. However, with systems of this type it is often difficult to
open the storage container because the vacuum inside the container
draws on the container lid. In addition, it is often not possible
for the user to recognize whether the desired vacuum is still
present in the storage container. Furthermore, it can be difficult
to maintain an adequate vacuum in the storage container,
particularly over a prolonged period of time.
[0004] Food storage container lids with venting or aerating valves
for pressure equalization during heating in a microwave oven are
known. For example, EP 0 633 196 A2 describes a mechanism of this
type. The venting or aerating valves can be used to prevent the
build-up of overpressure in the interior of a food storage
container when it is heated. Such a build-up of overpressure
typically occurs when there are aqueous liquids in the interior of
the container, and the liquids evaporate during heating, thereby
building up an overpressure in the container interior. The result
can be that sauces or other food within the container can spurt out
suddenly when the container lid is opened. EP 0 633 196 A2 proposes
a venting valve in the lid of the food storage container. The
venting valve is to be opened before the container is placed in a
microwave oven. The water vapor which develops during heating can
then escape unhindered through the valve, without a corresponding
build-up of vapor pressure in the interior of the sealed container.
It is not intended to achieve thereby the improved storage of food
under vacuum, or the indication of the pressure level in the food
storage container.
[0005] In EP 0 820 939 A1, the object is to provide a food storage
container with venting capability, so that food stored inside the
container can be safely heated in a microwave oven with the
container lid closed. Unlike EP 0 633 196 A2, a valve mechanism is
described which can be opened by way of a joint like a rocker.
Hence all that is required is to press in the rocker lever for the
valve to open with ease. Here, too, there is no intention to use
the valve mechanism to improve the storage of food under vacuum or
to indicate the pressure level in the food storage container.
[0006] EP 0 644 128 A1 describes a food storage container having a
container lid with a recess in which several vent openings are
formed. The vent openings are closed by a seal when a vacuum exists
in the holding space. The seal has pin-shaped anchor bars which
project upwardly a small amount out of the recess and grow thicker
at their ends. These anchor bars serve to lift the seal off the
vent openings when air is to enter the holding space of the storage
container from outside. Relatively high manual forces need to be
applied to open this valve.
[0007] WO 88/00560 describes an opening mechanism for a plastic
beverage can, and allows for a kind of visual check of pressure
level. The beverage can has a plastic lid (the lids involved tend
to be plastic, since one object is to avoid using metal lids) which
bulges outward when the pressure inside the container is above
atmospheric pressure. Such an arrangement does not allow for any
quantitative conclusions about the magnitude of the pressure above
atmospheric inside the container. Pressure equalization can occur
by opening a venting valve, making it easier to subsequently remove
the entire lid. The equalization of overpressure in the container
interior (as a result of carbonated beverages, for example) plays a
role in this case. This opening mechanism does not, however, allow
for re-closure and the corresponding build-up of pressure.
[0008] CH 304 374 discloses a closure lid for an aluminum
sterilizing container. The lid has an essentially
circular-ring-shaped configuration, and is mounted on a cylindrical
aluminum container. A rubber seal is placed between the edge of the
lid and the upper brim of the container. In the middle of the
container lid there is an additional opening which is covered by a
rubber cap. The rubber cap provides a visual check, indicating
whether there is a vacuum inside the container. As long as the
pressure inside the container is adequately below atmospheric
pressure, the rubber cap bulges inward a corresponding amount. This
bulge diminishes continually as the vacuum decreases. Hence it is
difficult for the observer to decide whether the pressure level
inside the container is adequate for ensuring the freshness of the
food inside the container.
[0009] Finally, DE 100 60 999 C1 describes a food storage container
including a container lid with an opening mechanism for ventilating
the evacuated container before it is opened. According to one
embodiment, a sealing tongue is raised up from a vent via a driver.
The sealing membrane and a pressure indicator are fastened directly
on the container lid. The opening tab is connected non-releasably
to the container lid via a film hinge. This mechanism provides an
improved possibility for storing food under vacuum. The opening of
the lid is facilitated by prior ventilation and the pressure
indicator indicates the state of pressure in the container
interior. However, disadvantages of this mechanism include the
costly installation of the sealing components directly on the
container lid, and the complicated driver mechanism of the one-way
valve, which is susceptible to defects. Furthermore, the
possibility of exchanging the valve mechanism is limited.
SUMMARY
[0010] In one aspect, the invention features a lid for a food
storage container. The lid includes a lid body defining a vacuum
sense opening. A vent opening extends through the lid body. The lid
also includes a releasable cover disposed over the vent opening.
The cover impedes air flow into the container through the vent
opening until the cover is released. The lid further includes a
pressure indicating dome. The pressure indicating dome defines a
cavity, and is in hydraulic communication with the container
through the vacuum sense opening. The pressure indicating dome
includes a membrane that collapses toward the vacuum sense opening
in response to negative container pressure. One advantage of this
lid and of the pressure indicating dome is that they can be easy
and economical to manufacture. The pressure indicating dome can
permit simplified evacuation of a container by allowing the user to
immediately see when a sufficient vacuum has been attained inside
the container. The pressure indicating dome can provide a visual
and/or tactile signal of the status of the pressure inside the
container.
[0011] The visual impact of the membrane of the pressure indicating
dome, which can be made of an elastomeric plastic material, can be
increased by, e.g., designing the membrane in an easily visible
color. Such an embodiment can allow for particularly easy viewing
of the pressure indicating dome, as well as a clear indication of
the pressure in the food storage container.
[0012] Another advantage of the pressure indicating dome is that it
can enable even users with poor vision to determine the condition
of pressure inside a storage container through tactile means (e.g.,
by determining the degree to which the pressure indicating dome
projects beyond, or disappears within, the outer contour of the
cover).
[0013] In some embodiments, the lid further includes a resilient
layer that is in contact with the membrane. The resilient layer can
include a spring sheet and/or an elastomeric polymer. The resilient
layer can be formed, for example, by selecting a suitable resilient
plastic material for the membrane of the pressure indicating dome
or by inserting a spring metal in the membrane of the pressure
indicating dome. An advantage of this embodiment is that when the
interior of the storage container is at ambient pressure, the
membrane of the pressure indicating dome can project distinctly
outward.
[0014] In some cases, the pressure indicating dome is capable of
indicating two discrete states: (1) the interior of the storage
container being at a pressure that is sufficiently below
atmospheric pressure, and (2) the interior of the storage container
being at a pressure that is insufficiently below atmospheric
pressure. An advantage of this embodiment is that the pressure
indicating dome can adopt an umnistakable signal position. In other
words, if a pre-defined pressure below atmospheric pressure is
attained inside the container, then the membrane can "snap" inward.
In some cases, e.g., when the membrane includes a spring, the
membrane can be guaranteed to snap back into its initial position
when a minimum pressure below atmospheric is exceeded inside the
storage container. In such cases, the pressure indicating dome can
have only two unmistakable positions: sufficient pressure below
atmospheric inside the storage container (the pressure indicating
dome is snapped inward), and insufficient pressure below
atmospheric or ambient pressure (the pressure indicating dome is in
its initial position).
[0015] In some cases, the pressure indicating dome has an
essentially cup-shaped configuration with a planar top adjoined by
a conically widening annular wall. Such an embodiment of the
pressure indicating dome can allow for a clear indication of good
or poor vacuum in the container interior. It can avoid a gradual
shifting motion by the pressure indicating dome. The annular wall
can be slightly outwardly domed, which can allow the pressure
indicating dome to be folded together with particularly little
friction. There can be no notable rubbing of the side wall when the
pressure indicating dome is rolled together.
[0016] In certain embodiments, the cover also defines an indicator
opening. Under certain pressure conditions, the membrane extends
through the indicator opening. A benefit to this embodiment is that
the pressure indicating dome can penetrate the indicator opening as
soon as the vacuum in the container interior is inadequate (without
penetrating the indicator opening when there is sufficient vacuum
in the container interior).
[0017] In some cases, the membrane is formed of a plastic resin.
The plastic resin can be selected to maintain dimensional stability
of the membrane over a temperature range between about -40.degree.
C. and about 100.degree. C. An advantage to this embodiment is that
it can allow the storage container and its contents to be stored in
a freezer and later to be defrosted in a microwave oven.
[0018] In some embodiments, the lid includes a one-way valve. The
one-way valve can include a movable sealing tab. The pressure
indicating dome can be integrally connected with the one-way valve
(e.g., the pressure indicating dome can be integrally connected
with the movable sealing tab). In such cases, the integral
one-piece construction including the pressure indicating dome and
the one-way valve can include a relatively stiff material and/or a
material possessing sealing properties. An advantage of this
embodiment is that it can be economical to manufacture (e.g., as an
injection molding). Furthermore, it can be easily mounted on the
storage container.
[0019] In some cases, the components of the valve device are
provided separately from the food storage container, and are
removably fastened to the food storage container. Advantages of
such an embodiment can include simple installation during
production and/or the repair or exchange of defective components.
Furthermore, the components do not need to be assembled at their
site of manufacture.
[0020] In some embodiments, the cover is pivotably connected to the
lid body by a hinge. The hinge can be formed integrally on, e.g.,
the lid body. The hinge can be of a material with inherent spring
characteristics, which can enable the hinge simply to be snapped
into a hinge holder fitted, for example, to the lid body.
[0021] The pressure indicating dome can include a spring. The
stiffness of the spring can be set or selected retrospectively to
the desired response pressure (i.e. to the value of the container
pressure at which the pressure indicating dome is triggered). The
pressure indicating dome can include a resilient material. An
advantage to such a pressure indicating dome is that it can have a
low number of required components and it can be simply
installed.
[0022] In some cases, the cover is produced by an injection molding
process.
[0023] In another aspect, the invention features a lid for a food
storage container. The lid has a lid body with a vent opening in
it, and a releasable cover disposed over the vent opening. The
releasable cover impedes air flow into the container through the
vent opening until the cover is released. The releasable cover has
an evacuation opening. The lid also includes a membrane that covers
the vent hole until the cover is released. The lid further has a
driving element that is connected to the membrane at one end and
disposed within the evacuation opening at another end.
[0024] The lid can have the advantage of being easy and economical
to manufacture. Further, the lid can be opened easily because the
membrane, which simply rests on the vent hole, can be lifted off
the vent hole by pulling open the cover by way of the driving
element. This operation can be comfortably performed without any
particular effort because of the leverage between the cover, the
driving element and the sealing tab. This can result in pressure
equalization between the interior of the container and the
surroundings. The container lid is no longer drawn by the vacuum in
the interior of the storage container and can be lifted off it with
ease. It is also possible for the opening assembly to be positioned
in the upper area of the outer wall of the container, above its
maximum filling level, such that no food is sucked into the vacuum
pump when air is evacuated from the storage container.
[0025] In some embodiments, the membrane is of an elastomeric
plastic and/or acts as a one-way valve. The membrane can be
constructed as a rectangular plastic strip, for example, with one
narrow side connected to the container lid body or an elastomeric
plastic layer attached thereto. This fastening edge can act as an
elastic joint. During the evacuation operation the membrane can be
swiveled upward from the vent opening by the suction effect of the
suction device, i.e., the membrane can be lifted clear of the vent
opening, enabling air present in the storage container to be drawn
off by the suction device. Once the storage container is evacuated,
sealing can take place automatically by the membrane being drawn
against the vent opening in the lid body.
[0026] The membrane can be a sealing tab.
[0027] In some cases, the driving element has a rim. This can allow
for a simple connection of the driving element to the cover without
the parts being joined together by way of threaded connections or
any other special connecting elements. If the driving element is
elastically made of plastic, the rim can be elastically squeezed
together and pushed through the evacuation opening in the cover so
that subsequently the rim covers the evacuation opening and can no
longer slip through the evacuation opening.
[0028] In some embodiments, the cover can be pressed into a recess
of the lid body and locked in the recess for the storage state of
the storage container. It can thus be easily possible for several
storage containers with their storage lids to be stacked on top of
each other without the cover projecting in obstructing manner from
the upper side of the container lid body. The lid can include a
recessed grip such that it can be possible, even if the cover is
clipped in place within a recess of the container lid body, for a
user to grip in the gap with one finger in order to lift the cover.
The grip surface can be oriented at an upward angle, away from the
container lid body.
[0029] The driving element can be integrally connected to the
membrane. The driving element can be constructed, for example, as a
spigot standing essentially perpendicular on the membrane, with a
circumferential edge positioned in its upper area. In this
arrangement the driving element can be made of an elastic
material.
[0030] In certain embodiments, the cover has a surface that extends
about the evacuation opening and that is adapted to receive a
sealing lip of a vacuum pump.
[0031] In some cases, the lid body is of a plastic resin (e.g.,
polypropylene, polyamide, and/or other temperature- and
aging-resistant plastic materials) that is selected to maintain
dimensional stability of the membrane over a temperature range of
between -40.degree. C. and 100.degree. C. In such cases, it can be
possible for the storage container and its contents to be stored in
a deep-freezer and then to be defrosted in a microwave oven. The
vent opening can be opened by way of the cover for heating in a
microwave oven. Possible materials are polypropylene and polyamide
as well as any other temperature- and aging-resistant plastic
material.
[0032] The lid body can further include a pressure indicator.
[0033] In some cases, the container lid body and the cover can be
manufactured as a joint injection molding. The cover can be
integrally connected to the lid body by a hinge. For the membrane
and the pressure indicator, it is possible to use an elastomeric
plastic or rubber material, which can then be inserted with a
sealing effect in the component made up of the container lid body
and the cover.
[0034] The lid can be universally used with different food storage
containers. If the vent assembly is positioned on the container,
then the outer surface of the cover adjacent the evacuating opening
preferably faces at an angle in an upward direction in order to be
better able to mount a vacuum pump on the container wall. This can
also facilitate the handling of the vent assembly.
[0035] Implementations of the invention can have one or more of the
following advantages. The pressure indicator and/or the opening and
closing mechanism of the storage container can be easy and
inexpensive to manufacture. The storage container can be opened
without any major effort. In some cases, only the smallest possible
forces are needed to cause the membrane to lift off of the vent
opening and to reduce the vacuum inside the storage container.
Uncontrolled spraying of food out of a vent opening due to
overpressure can be minimized. As a result, the likelihood of a
user being soiled and/or scalded when using the container can be
reduced.
[0036] The cover can perform several functions, and thereby save
space and cost. In other words, the cover can act as a coupling
element for receiving and forming a tight connection with a vacuum
pump, as an actuating and opening element for the one-way valve
formed together with the membrane and the vent opening, and/or as
an impact guard for the container lid.
[0037] The pressure indicating dome can allow a user to immediately
see when there is a sufficient vacuum inside a storage container.
The pressure indicating dome can provide a visual and/or tactile
signal of the pressure condition inside a storage container. The
membrane of the pressure indicating dome can include, e.g., an
elastomeric plastic material which can be of an easily visible
color. The pressure indicating dome can enable a user with poor
vision to determine the condition of pressure inside the storage
container by means of touch. A lid with a pressure indicating dome
can serve as a multi-function component.
[0038] The valve device can have the advantage of being simple to
fit and having few components. The valve device can be exchanged or
fixed (if, for example, a leakage or the like suddenly occurs). The
valve device can be multifunctional, simultaneously providing a
connection for a vacuum pump, pressure indication, and
ventilation.
[0039] The details of one or more embodiments of the invention are
set forth in the accompanying drawings and the description below.
Other features and advantages of the invention will be apparent
from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
[0040] FIG. 1 is a schematic cross-sectional view of a first valve
device for a food storage container when there is an insufficient
vacuum inside of the container.
[0041] FIG. 2 is a schematic cross-sectional view of the valve
device of FIG. 1, when there is a sufficient vacuum inside of the
container.
[0042] FIG. 3 is a schematic cross-sectional view of the valve
device of FIG. 1, when the inside of the storage container is at
atmospheric pressure.
[0043] FIG. 4 is a perspective view, partially in cross-section, of
a second valve device for a food storage container, when there is
an insufficient vacuum inside of the container.
[0044] FIG. 5 is a perspective view, partially in cross-section, of
the valve device of FIG. 4, when a vent has been opened in the
storage container.
[0045] FIG. 6 is a perspective view of a food storage container
including the valve device of FIG. 4.
[0046] FIG. 7 is a schematic cross-sectional view of a third valve
device, in the fitted state.
[0047] FIG. 8 is a perspective exploded view of the valve device of
FIG. 7.
[0048] FIG. 9 is a perspective view of a fourth valve device, in
the fitted state.
[0049] FIG. 10 is a perspective exploded view of the valve device
from FIG. 9.
DETAILED DESCRIPTION
[0050] Referring to FIGS. 1-3, a valve device 1, which is
engageable with a food storage container 15, includes a pressure
indicator 6.
[0051] Referring now to FIGS. 1-6, valve device 1 is mounted on a
container lid 2. A cover 7 is integrally connected to container lid
2 by means of a film hinge 32. Cover 7 and container lid 2 are
injection moldings made of temperature-resistant thermoplastic
material. Cover 7, which in the plan view can be in the form of an
oval plate, includes a connecting device 9. Connecting device 9
allows container lid 2 to releasably engage a vacuum pump--i.e.,
connecting device 9 provides a suction port for a vacuum pump.
Connecting device 9 is formed by a smooth annular surface 18 on the
outer side 210 of cover 7, and by one or more openings 17 within
annular surface 18. A suitable connecting device is described in a
U.S. patent application filed concurrently herewith, entitled "Food
Storage Containers" and assigned Ser. No. ______, the entire
contents of which are hereby incorporated by reference.
[0052] A sealing tab 3 (of, e.g., elastomeric plastic) is disposed
on the lower side of cover 7, underneath connecting device 9. In
the valve device 1 shown in FIGS. 1-3, sealing tab 3 is fastened to
cover 7 by a circular-ring-shaped bar 19, and is a separate
component in the shape of a disk. Bar 19 has an air passage 30.
[0053] In FIGS. 1-6, cover 7 is inserted in a recess 20 in
container lid 2. Recess 20, which is essentially rectangular, is
adapted to conform to cover 7. Container lid 2 includes a vent hole
4 under connecting device 9 of cover 7, and under sealing tab 3.
When open, vent hole 4 provides a connection between the atmosphere
and the interior 22 of storage container 15. When closed, vent hole
4 is closed air-tight by sealing tab 3. Vent hole 4 and sealing tab
3 together form a one-way valve 40, which closes in the direction
of storage container 15.
[0054] A vacuum sense opening 5 in container lid 2 is arranged
adjacent to vent hole 4. Pressure indicator 6 includes a plastic
membrane 220 which provides an air-tight covering for vacuum sense
opening 5. Pressure indicator 6 extends in an upward direction,
essentially perpendicular to the plane of container lid 2. When
there is an insufficient vacuum in the container, the entire
pressure indicator projects upward relative to the plane of
container lid 2. In other words, pressure indicator 6 displays an
essentially cup-shaped and slightly outwardly domed side wall 23,
which tapers in an upward direction and terminates with a
horizontally extending circular base 24, as shown in FIGS. 1 and
3-5. Referring specifically to FIGS. 2 and 4, top 24 has a diameter
"D" which is smaller than the diameter "d" of the opening on base
25 of pressure indicator 6. As shown in FIG. 2, side wall 23 of
pressure indicator 6 folds into a cavity 26 (FIG. 1) in the
pressure indicator when exposed to vacuum.
[0055] Referring to FIGS. 1-6, cover 7 includes an indicator
opening 8 at the position of pressure indicator 6. When the
pressure in interior 22 of storage container 15 is not sufficiently
below atmospheric pressure, pressure indicator 6 extends vertically
out of indicator opening 8, past the outer surface 33 of cover 7.
Pressure indicator 6 can be made of an elastomeric plastic.
Preferably, pressure indicator 6 is of an easily visible color,
such as red (to, for example, distinguish it from the surrounding
material of the lid). In FIGS. 1-3, pressure indicator 6 is
reinforced on its inner side by a layer 12 that preferably includes
a resilient material, such as a spring sheet or elastomeric
plastic. The surface of layer 12 is engaged with the inner side 34
of the pressure indicator 6.
[0056] In FIGS. 1-6, the section of cover 7 that is closest to the
edge of storage container 15 has a gripping surface 10. For
example, as shown in FIGS. 1-6, an end of cover 7 is beveled
slightly upward starting at point 35, thereby forming gripping
surface 10. Container lid 2 includes a recess 20 with a bottom 37.
Cover 7 is separated from bottom 37 of recess 20 by ribs 29 and 36.
Thus, gripping surface 10 of cover 7 can be comfortably gripped
between a user's finger and thumb (not shown) and pulled open in an
upward direction.
[0057] FIGS. 1-3 show a retaining clip 11 which presses the
elastomeric plastic material of the planar base 25 of pressure
indicator 6 against container lid 2. Retaining clip 11 is supported
by walls of container lid 2 (not shown). In FIGS. 1-3, cup-shaped
pressure indicator 6 is integrally connected to base 25. Thus, when
pressure indicator 6 is clamped by retaining clip 11, the pressure
indicator effectively is sealed to container lid 2.
[0058] Referring to FIGS. 4-6, a second example of a valve device 1
also includes a pressure indicator 6 for a food storage container
15. In the valve device 1 of FIGS. 4-6, cover 7 is again integrally
connected to container lid 2 by means of a film hinge 32. Sealing
tab 3 is arranged underneath connecting device 9 of cover 7.
Sealing tab 3 is connected to cover 7 by a driving element 13.
Sealing tab 3, driving element 13, base 25, and pressure indicator
6 all are made of a single elastomeric plastic part which is
fastened as an insert to a bead 21 in recess 20 of container lid 2.
The plastic material used for pressure indicator 6 has spring-like
properties, such that pressure indicator 6 can snap into a position
that indicates whether there is a sufficient vacuum inside the
container.
[0059] Thus, there are some differences between the valve device 1
of FIGS. 1-3 and the valve device 1 of FIGS. 4-6. In FIGS. 1-3,
sealing tab 3 forms a separate sealing part relative to pressure
indicator 6. In the valve device 1 of FIGS. 4-6, on the other hand,
these parts are formed by a single elastomeric component--sealing
tab 3 is partially cut out of base 25, thereby forming a gap 28.
Furthermore, in FIGS. 4-5, a circumferential seal 14 is disposed
around the edge of container lid 2. Seal 14 enables lid 2 to be
closed air-tight against storage container 15. In FIGS. 1-3, on the
other hand, lid 2 itself forms a tight closure with storage
container 15 (i.e., there is no circumferential seal 14).
[0060] Referring back to FIGS. 4-6, when valve device 1 is closed,
circumferential rib 29 presses base 25 against the bottom 37 of
recess 20, thus effecting a seal. In FIGS. 1-3, base 25 is pressed
against container lid 2 by retaining clip 11, which is fitted to
lid 2 by latching. In FIGS. 4 and 5, cover 7 performs the same
function as retaining clip 11 does in FIGS. 1-3, so that there is
no need for a separate retaining clip.
[0061] Another difference between the valve device 1 of FIGS. 1-3
and that of FIGS. 4-6 is that the valve device shown in FIGS. 4-6
includes driving element 13, while the valve device shown in FIGS.
1-3 does not.
[0062] In FIGS. 1 and 3-6, the pressure in the interior 22 of
storage container 15 is equal to ambient pressure. Because of its
spring bias, pressure indicator 6 thus projects out through
indicator opening 8 and beyond cover 7.
[0063] In FIG. 2, there is sufficient vacuum in the interior 22 of
storage container 15. Pressure indicator 6 is thus drawn into
cavity 26, toward container interior 22. The pressure indicator is
in a folded or snapped-in condition. In this state, pressure
indicator 6 either does not project at all beyond the outer contour
of cover 7, or else projects beyond the outer contour by a
negligible amount. Pressure indicator 6 folds like a rolling
membrane. The ratio of diameter "D" to diameter "d" is selected
based on the wall thickness "f" and the elastic material of
pressure indicator 6, so that pressure indicator 6 will abruptly
fold together when there is a sufficient vacuum in the interior of
the container (as shown in FIG. 2). If the vacuum in container
interior 22 decreases, then at the point of insufficient vacuum,
pressure indicator 6 will make an abrupt outward movement, snapping
back into the position shown in FIGS. 1 and 3-6. Thus, gradual
shifting of pressure indicator 6 is avoided, and the user has a
clear indication of whether there is a sufficient vacuum in the
container.
[0064] A user can first inform himself about the pressure status in
container interior 22 by checking the position of pressure
indicator 6 when container lid 2 is closed. If the bottom of
pressure indicator 6 projects out through indicator opening 8, then
the pressure in container interior 22 is insufficient for
guaranteeing the storage of food under vacuum conditions (as is the
case in FIGS. 1, 4, and 6).
[0065] In FIGS. 1, 3, and 6, storage container 15 is evacuated. To
evacuate the container, a suction port with a circumferential
sealing lip of a vacuum pump (not shown) is placed on connecting
device 9 of valve device 1. Then, the vacuum pump is put into
operation, causing vent hole 4 of valve device 1 to automatically
open. Vent hole 4 opens because the suction effect of the vacuum
pump causes sealing tab 3 to lift off from vent hole 4, and the air
contained in storage container 15 is drawn off by the vacuum pump.
In FIG. 1, the air is drawn through vent hole 4, past the side of
sealing seat 38 of sealing tab 3, around the outside of sealing tab
3, through air passage 30, and through connecting device 9 to the
vacuum pump. As shown in FIG. 2, when a sufficient vacuum is
attained in the interior 22 of storage container 15, pressure
indicator 6 suddenly snaps inward, thereby informing the user that
he can end the evacuation operation. After the vacuum pump is
disengaged from connecting device 9, sealing tab 3 is pressed
against the edge of vent hole 4, automatically closing it
air-tight. This operation also occurs with each return stroke of
the vacuum pump, in order to enable a vacuum to be built up in
interior 22. The vacuum in interior 22 keeps enclosed food fresh
for a long time because lack of oxygen prevents the food from being
oxidized.
[0066] To remove food from storage container 15, the user grips
cover 7 with two fingers under gripping surface 10 and, with little
force, swivels cover 7 in a counterclockwise direction (as shown in
FIG. 5). Referring to FIG. 3, sealing tab 3 is thus lifted by cover
7 in an upward direction, off sealing seat 38, and vent hole 4 is
cleared. In the valve device 1 shown in FIG. 5, the upper side of
cover 7 first comes up against the lower side of a rim 230 formed
on driving element 13. The upper side of cover 7 then pulls driving
element 13 and sealing tab 3 upward, until sealing tab 3 lifts off
from sealing seat 38 and swivels upward in a counterclockwise
direction. Referring to FIGS. 3 and 5, air can now flow into
container 2 via vent hole 4. The distance 5 between rim 230 and the
upper side of cover 7 is sufficiently large to prevent the upper
side of cover 7 from striking rim 230 until after cover 7 has been
released from the latching arrangement (not shown) in recess 20.
Such a structure helps to keep the actuating forces low.
[0067] Container lid 2 can now be removed from storage container 15
without any notable effort. In FIGS. 4-5, sealing tab 3, which is
partially separated from the rest of planar base 25 by gap 28, and
which is connected to base 25 only in area 39, repeatedly falls
back onto vent hole 4 as a one-way valve acting under the force of
gravity. Thus, it is relatively easy to produce a vacuum in the
container. It also is conceivable, however, for cover 7 to be
designed to snap into place by means of clip connectors on
container lid 2, thereby enabling sealing tab 3 to close vent hole
4. The material of sealing tab 4 and base 25 can be elastic enough
as to cause vent hole 4 to be closed a result of the closing moment
acting on it when there is no difference in pressure. Sealing tab 3
does not lift off vent hole 4 until there is a difference in
pressure (i.e., sealing tab 3 works like a one-way valve).
Referring to FIG. 3, sealing tab 3 is lifted when cover 7 is
swiveled around film hinge 32 because sealing tab 3 is fastened
with clearance to cover 7, in order to perform the function of a
one-way valve.
[0068] Referring to FIG. 6, a thermoplastic food storage container
15 includes valve device 1 from FIG. 4. Storage container 15 has a
container body 16 in the shape of a right-parallelepiped and, when
viewed from the top, has an essentially rectangular container lid 2
with a circumferential rim 27. Valve device 1 is arranged in a
recess 20 on one of the narrow sides of container lid 2. Gripping
surface 10 of cover 7 terminates approximately with outer surface
33 of container lid 2. When there is insufficient vacuum inside of
the container, only pressure indicator 6 projects vertically out of
indicator opening 8 of cover 7.
[0069] Adjacent to pressure indicator 6 are connecting device 9
(e.g., a circular connecting device), with smooth annular surface
18, and evacuation hole 17, from which driving element 13 projects
with its rim 230. Rim 230 improves the driving effect of driving
element 13 when cover 7 is swiveled upward. Through the leverage
produced by distances "R" and "r" (shown in FIG. 5), relatively
little manual force "F" (shown in FIG. 4) needs to be applied to
grip surface 10 and lift sealing tab 3 from sealing seat 38, even
when there is still a vacuum in interior 22 of the container. As
distance "r" becomes smaller and distance "R" becomes larger, it
becomes easier to open valve device 1.
[0070] When the valve device is assembled, the upper area of the
driving element can be pushed with the rim through evacuation hole
17, with the rim being elastically squeezed together until it has
penetrated the evacuation hole from the bottom up. Thereafter, the
rim can widen and act as a sort of barb. When cover 7 is swiveled
open, driving element 13 is moved upward over the rim in a curved
path. The loose end of the sealing tab which is connected to the
driving element is thus moved likewise in an upward direction, and
lifted clear of the vent hole.
[0071] Because of the distance between the lower side of the
driving element rim and the upper side of the evacuation hole, the
driving element initially slides through the evacuation hole when
the cover is swiveled. The rim does not abut and take support upon
the upper side of the cover until after the cover has executed a
certain swiveling motion about the bearing point, preferably in a
counterclockwise direction. From this moment on, the distance
between the lower side of the cover and the upper side of the
container lid is large enough for several fingers to grip
underneath the cover. Thus it is possible, with greater force if at
all necessary, to lift the sealing tab off the vent hole by the
cover, moving the driving element (and hence the sealing tab) in an
upward direction.
[0072] The fact that the driving element extends with a clearance
in evacuation hole 17 and is also elastically deformable within
certain limits means that the swivel movement of the cover on the
driving element is deflected in a direction of force extending
essentially perpendicular to the sealing surface of the valve
opening, with the result that only a small valve opening force is
needed to cause the sealing tab to lift off the valve seat of the
vent hole and to relieve the vacuum inside the storage
container.
[0073] The cross-section of the rim of the driving element
preferably is dimensioned sufficiently large for the rim to display
adequate rigidity, and not to slip through the evacuation hole when
the cover is pulled open. It is preferable instead for the rim to
rest on the upper side of the cover, and for the sealing tab to
reliably lift clear of the vent hole even in the presence of vacuum
in the container interior.
[0074] In FIGS. 7 and 8, a first example of a valve device 101 is
in the fitted, opened state. Valve device 101 is fitted to a
container lid 109 of a storage container 121 for food. Valve device
101 can be used to evacuate air from closed container 121, by means
of a connection surface 115 and an extraction opening 117. Valve
device 101 can also be used to ventilate evacuated container 121
for easy opening of container lid 109. In addition, the negative
pressure in the container is indicated by a pressure indicator 113
integrated in valve device 101.
[0075] Container lid 109 sits in the closed state on a container
wall 108 of storage container 121 and seals the latter in a
gas-tight manner together with a container seal 107, which is
designed as an encircling flat seal made from elastomeric plastic.
Container lid 109 (which can be produced from thermoplastic) has an
elongate depression 126 for holding valve device 101. A measuring
opening 112 with a circular cross section and a vent 111 having a
likewise circular cross section are provided in depression 126.
Vent 111 is fitted to a frustoconical projection.
[0076] Valve device 101 has a valve housing 104 that can be
produced from thermoplastic. Valve housing 104 has an elongate
shape which tapers in one direction and has rounded ends and an
encircling edge 123. In this case, a hinge 118 is integrally formed
on valve housing 104 at the wider end.
[0077] Encircling edge 123 surrounds a planar plastic surface 127
which, in its wider section arranged level with the vent 111, has a
first circular cutout 124 concentrically with vent 111. Edge 123,
which virtually forms an encircling wall, protrudes vertically
above and below plastic surface 127. Furthermore, a second circular
cutout 125 is provided in the narrow section of surface 127, i.e.
in the region of pressure indicator 113.
[0078] Encircling edge 123 provides a boundary and holder for a
membrane 102. Encircling edge 123 also serves as a clamping
connection for a valve housing cover 105. Valve housing cover 105
is likewise produced from thermoplastic. The valve housing and the
valve housing cover can be connected to each other by, e.g., a film
hinge. Valve housing cover 105 has essentially the same outer
contour as valve housing 104. A connection surface 115 having a
lenticular curvature and a central evacuation hole 117 is provided
in the region of first cutout 124. A circular indicator opening 114
is fitted in valve housing cover 105, in the region of second
cutout 125. Webs which are arranged on the inside of the valve
housing cover 105 cause membrane 102 to be pressed against plastic
surface 127 of valve housing 104.
[0079] Membrane 102 is an essentially sheet-like sealing insert
which can be produced from elastomeric plastic (e.g.,
polybutadiene, butadiene-styrene polymer, acrylonitrile copolymer,
polychlorobutadiene, isoprene rubber, aftertreated polyolefins,
polyurethane, or silicone rubber). In some cases, membrane 102 can
be produced from natural rubber or cork. Membrane 102 carries out a
plurality of functions simultaneously. First, membrane 102 has,
level with vent 111 and evacuation hole 117, a U-shaped incision,
what is referred to as sealing tongue 110. Sealing tongue 110 acts
as a one-way valve, i.e. sealing tongue 110 raises off from vent
111 during the extraction process undertaken by a vacuum pump (not
illustrated) which is fitted to connection surface 115. As soon as
the vacuum pump is removed, sealing tongue 110 closes vent 111
because of the negative pressure produced in container 121.
[0080] Second, one region of membrane 102 is designed as a pressure
indicator 113 which indicates the vacuum state in the container
interior. If a sufficient vacuum prevails in storage container 121,
the approximately semispherical pressure indicator 113 is pushed in
counter to the pressure of a spring 103 in the direction of
container 121, virtually in the manner of a concertina. If a limit
value is exceeded or if the pressure between the container interior
and surroundings is equalized, pressure indicator 113 is pushed out
through indicator opening 114 by compression spring 103, which is
designed as a helical spring.
[0081] Compression spring 103 is held in a spring holder 119 on
valve housing 104.
[0082] Finally, in the case of the valve device 101 of FIGS. 7 and
8, a sealing ring 106 is provided in the region of second cutout
125, said sealing ring sealing the connection of valve housing 104
to measuring opening 112 in container lid 109.
[0083] After storage container 121 has been filled with food,
container lid 109 is placed onto container wall 108, which is
provided with a container seal 107. Valve device 101 here is
closed, i.e. the food is packed in a gas-tight manner. A vacuum
pump (not illustrated) is now used to extract the air enclosed in
container 121 via evacuation hole 117, sealing tongue 110, and vent
111. So that air is exclusively extracted from container 121, and
not from the surroundings, a sealing edge 122 is formed on membrane
102 and seals the frustoconical elevation around vent 111. The
reaching of the required minimum negative pressure can be read off
using pressure indicator 113. Pressure indicator 113 disappears in
indicator opening 114 as soon as the required negative pressure is
reached.
[0084] When the equalization of pressure occurs over time, the time
at which a critical point is reached is indicated by pressure
indicator 113. Pressure indicator 113 is designed, if appropriate,
to be colored, and protrudes through indicator opening 114. In
other words, pressure indicator 113 is pressed beyond indicator
opening 114 by the spring force of spring 103. A spring with an
appropriate spring stiffness can be installed in pressure indicator
113 to help indicate pressure equalization.
[0085] In order to open container lid 109, which is sucked on
firmly by the negative pressure of the container, valve device 101
is grasped at handle 116 and pivoted about hinge 118. This causes
sealing tongue 110 to be lifted off from vent 111, and sealing ring
106 to be lifted off from sealing seat 128. Thus, storage container
121 is ventilated. After ventilation, container lid 109 can easily
be lifted off from container 121.
[0086] Referring now to FIGS. 9 and 10, a second example of a valve
device 101 in the fitted state has essentially three components:
valve housing 104, valve housing cover 105, and membrane 102. Such
a structure is possible in particular by the changed design of
pressure indicator 113, which is produced from a material having
inherent spring stiffness. This renders superfluous the compression
spring provided in the first example of the valve device. In
addition, the integration of a sealing lip 121 on the lower edge of
pressure indicator 113 saves an additional sealing ring for sealing
the measuring opening 112. Otherwise, the construction and the
function of the second valve device 101 correspond to that
described with reference to FIGS. 7 and 8.
[0087] A number of embodiments of the invention have been
described. Nevertheless, it will be understood that various
modifications may be made without departing from the spirit and
scope of the invention. Accordingly, other embodiments are within
the scope of the following claims.
* * * * *