Vacuum generating device for sealing perishable products and method of use

Abstract

A vacuum sealing device comprises a lid having a rigid rim with a lower opening for receiving a dish, an impermeable elastic membrane peripherally affixed to the rigid rim for sealing the dish, and a valve-less air evacuator formed between the elastic membrane and the dish rim. The valve-less evacuator allows air to flow out of the dish when the lid is being pressed and becomes closed when the lid is released to cause said lid to rebound to form a vacuum in the dish. The rigid rim prevents lid deformation when the lid is pressed, thus enabling the vacuum formation. To facilitate lid removal, the device has a valve-less vacuum releaser comprising a finger-receiving chamber and a section of the elastic membrane located above the chamber and connected to the rigid rim for releasing the vacuum in the dish. To prevent vacuum loss during storage in freezer or fridge, the elastic membrane is sufficiently thinned prior to being affixed to the rigid rim. In use, one places the lid on a dish, forces air out of the dish via the air evacuator between a section of the elastic membrane and the dish rim by pressing the lid, and releases the lid to cause the air evacuator to close and vacuum to form in the dish. To restore the device's capability to generate and maintain vacuum after numerous uses, the lid is exposed to a hot fluid having a temperature higher than 45° C. for a period of time.

1 . A vacuum generating device for sealing a perishable product comprising:
 a lid for a container adapted to receive the perishable product, said lid comprising a center section substantially impermeable to air to prevent air from permeating through into the container, a rigid rim located around said center section for receiving or surrounding the container, said rigid rim comprising a sufficiently rigid material to prevent it from being substantially deformed when said lid on the container is being pressed, and an elastic seal member connected or affixed to said rigid rim for forming an airtight seal to the rim of the container,   a valve-less air evacuator formed between a section of said seal member and the rim of the container, said valve-less air evacuator allowing the air to flow out of the container when said lid is being pressed and becoming closed when said lid is released to cause said lid to rebound and the space between said lid and container to expand to form a vacuum in the container; and   whereby in use, said lid is pressed to cause the air to flow out of the container via said valve-less air evacuator and is subsequently released to form said vacuum to cause the closing of said valve-less air evacuator, thereby preserving said vacuum for the perishable product in the container for an extended period of time.   
   
   
       2 . A vacuum generating device as defined in  claim 1  wherein said valve-less air evacuator comprises a portion of said seal member that is sufficiently more deformable than the rest of said seal member to enable an air passage to form between said portion of said seal member and the rim of the container as said lid is being pressed and that is sufficiently elastic to stamp out said air passage when said lid is released to form said vacuum. 
   
   
       3 . A vacuum generating device as defined in  claim 1  wherein said seal member comprises an elastic membrane attached or affixed to said rigid rim, said elastic membrane having a lower surface for sealing to the rim of the container and an upper surface. 
   
   
       4 . A vacuum generating device as defined in  claim 3  wherein said elastic membrane comprises a section having a lower tension force than the rest of said elastic membrane to form said valve-less air evacuator between said lower tension section of said elastic membrane and the rim of the container. 
   
   
       5 . A vacuum generating device as defined in  claim 1  wherein said valve-less air evacuator comprises at least one of a protruded section and a recessed section for said seal member to form at least one opening between said seal member and the rim of the container to allow air to flow out of the container as said lid is being pressed, said seal member being sufficiently elastic and flexible to stamp out said at least one opening upon release of the lid to form said vacuum. 
   
   
       6 . A vacuum generating device as defined in  claim 5  wherein the width (w) to height (h) ratio w/h of said at least one of a protruded section and a recessed section is larger than 4. 
   
   
       7 . A vacuum generating device as defined in  claim 6  wherein the maximum thickness of said seal member allowed for said valve-less air evacuator to work is 0.25 times of the width (w) of said at least one of a protruded section and a recessed section. 
   
   
       8 . A vacuum generating device as defined in  claim 5  wherein said seal member and center section of said lid comprise an elastic membrane, the periphery of said elastic membrane being attached or affixed to said rigid rim. 
   
   
       9 . A vacuum generating device as defined in  claim 8  wherein said at least one of a protruded section and a recessed section is formed by providing at least one of a protrusion and a recession along the inner perimeter of said rigid rim and by connecting or affixing said elastic membrane to said rigid rim in such a way that the outer part of said elastic membrane conforms to the contour of said inner perimeter of said rigid rim. 
   
   
       10 . A vacuum generating device as defined in  claim 8  wherein said rigid rim has a first rim having a recession along its inner perimeter and a second rim having a protrusion receivable in said recession of said first rim, said first and second rims being adapted to sandwich and affix the peripheral part of said elastic membrane between said first and second rims to form said at least one of a protruded section and a recessed section. 
   
   
       11 . A vacuum generating device as defined in  claim 8  wherein said at least one of a protruded section and a recessed section is sufficiently wide and high to make said at least one opening between said elastic membrane and the rim of the container sufficiently large to prevent the sucking-in of said elastic membrane after microwave oven heating, thereby preventing potential crushing of the perishable product in the container or damaging of the elastic membrane during said sucking-in. 
   
   
       12 . A vacuum generating device as defined in  claim 1  wherein said center section and seal member of said lid comprise an elastic membrane and, wherein said valve-less air evacuator comprises a sufficiently large protruded or recessed section for said elastic membrane to form a sufficiently large air passage between the container's rim and said elastic membrane to prevent the sucking-in of said elastic membrane after microwave oven heating, thereby preventing potential crushing of the perishable product in the container or damaging of the elastic membrane by said sucking-in. 
   
   
       13 . A vacuum generating device as defined in  claim 1  wherein said center section and seal member of said lid comprise an elastic membrane and, wherein said valve-less air evacuator comprises at least one protruded section adapted to cause said lid to tilt sufficiently on said container to prevent the sucking-in of said elastic membrane after microwave oven heating, thereby preventing potential crushing of the perishable product in the container or damaging of the elastic membrane during said sucking-in. 
   
   
       14 . A vacuum generating device as defined in  claim 1  wherein at least said seal member of said lid comprises an elastic membrane, said elastic membrane being substantially thinned prior to being attached or affixed to said rigid rim to prevent the loss of vacuum in the container during an extended period of storage. 
   
   
       15 . A vacuum generating device as defined in  claim 1  further comprising a valve-less vacuum releaser for releasing the vacuum in the container, thereby allowing the removal of said lid, said releaser being sufficiently large to allow a finger or finger-like member to reach and push said seal member away from the rim of the container to produce a passage for air to enter the container. 
   
   
       16 . A vacuum generating device for sealing a perishable product comprising:
 a center section substantially impermeable to air to prevent air from permeating into the container;   a rim connected or adapted to connect to said center section and comprising a sufficiently rigid material adapted to prevent said rim from being substantially deformed when a force or pressure is applied to said center section;   an elastic seal member connected or adapted to connect to said rim for forming an airtight seal to the container, and   a valve-less air evacuator comprising a release section of said elastic seal member for controlling air flow without a valve, said valve-less air evacuator being adapted to form an air passage between said release section and the container to allow air to flow out of the container when at least one of a force, pressure and vacuum is applied to said device to remove air from the container and to close said air passage when said at least one of said force, pressure and vacuum is removed, thereby sealing the container and preserving the vacuum therein.   
   
   
       17 . A vacuum generating device as defined in  claim 16  wherein said release section is adapted to be more deformable than at least some other part of said elastic member affixed to said rim to enable said air passage to form between said release section and the container. 
   
   
       18 . A vacuum generating device as defined in  claim 16  wherein said release section is adapted to have lower tension than at least some other part of said elastic membrane to allow said air passage to form between said release section and the container. 
   
   
       19 . A vacuum generating device as defined in  claim 16  wherein said elastic seal member is sufficiently stretched during the assembly of said device to reduce the thickness of said seal member and maintain said member in a stretched condition before said elastic seal member is sealed to the container, thereby improving the vacuum seal for the perishable product. 
   
   
       20 . A vacuum generating device as defined in  claim 16  wherein said center section and elastic seal member comprise an elastic membrane that is sufficiently stretched to reduce its thickness by at least 3% and affixed to said rim to keep said elastic membrane in a stretched condition under tension when said device is not in use or not applied to the container. 
   
   
       21 . A vacuum generating device as defined in  claim 16  wherein said rim comprises a first rigid rim and a second rim, wherein during the assembly said elastic membrane is sandwiched between said first and second rims and stretched to reduce its thickness by at least 3% as compared with the original thickness of the elastic membrane in its original non-stretched condition prior to the assembly. 
   
   
       22 . A vacuum generating device as defined in  claim 16  wherein said elastic seal member has a first section for sealing to the container and a second section connected to a part of said first section and extending out of the container, wherein said rim comprises at least one of an outwardly protruding section and inwardly receding section, said device further comprising a valve-less vacuum releaser including said second section and said one of said outwardly protruding and inwardly receding sections, wherein said second section of said seal member is defined by said one of said outwardly protruding and inwardly receding sections and is smaller than said first section but enough large to allow a finger-like member or finger to push said elastic membrane away from the container to release the vacuum therein. 
   
   
       23 . A vacuum generating device as defined in  claim 16  further comprising a valve-less vacuum releaser having at least one of a beam and a plate connected to said rigid rim and extending over a section of said elastic membrane to facilitate the release of the vacuum in the container. 
   
   
       24 . A vacuum generating device as defined in  claim 16  further comprising a valve-less vacuum releaser comprising an annular ring or ridge extending inwardly and spaced above said elastic membrane. 
   
   
       25 . A method for using a vacuum generating device to seal a perishable product comprising a lid for a container adapted to receive the perishable product, said lid comprising a center section substantially impermeable to air to prevent air from permeating through into the container, a rigid rim located around said center section for surrounding the container, said rigid rim comprising a sufficiently rigid material to prevent said rigid rim from being substantially deformed when said lid on the container is pressed, an elastic seal member connected to said rigid rim for sealing to the rim of the container, and an air evacuator formed between a section of said seal member and the rim of the container, said method comprising:
 placing said lid on the container containing a perishable product;   forcing air out of the container via said air evacuator between said section of said elastic seal member and the rim of the container by pressing said lid on the container; and   releasing said lid to allow the space between said lid and container to expand to form a vacuum therein.   
   
   
       26 . A method as defined in claim  30  further comprising a step of lifting a portion of said rigid rim slightly during said step of forcing air out of the container and a step of letting said portion of said rigid rim down prior to said step of releasing said lid, thereby producing a deeper vacuum in said container. 
   
   
       27 . A method as defined in claim  30  wherein said seal member comprise an elastic membrane having a peripheral section affixed to said rigid rim, said method further comprising a step of exposing said lid to a hot fluid having a temperature higher than 45° C. for a period of time to restore said lid's capability to generate and maintain vacuum in the container after said lid is used one or more times. 
   
   
       28 . A method as defined in claim  30  wherein said device further comprises a valve-less vacuum releaser for releasing the vacuum in the container, said valve-less vacuum releaser comprising one of an outwardly protruded section extending at least partially horizontally from said rigid rim of said lid and an inwardly recessed section extending at least partially horizontally from the rim of the container and a section of said elastic seal member located within said one of said outwardly protruded and inwardly recessed sections, said method further comprising a step of pushing said section of said elastic seal member away from the rim of the container by a finger or finger-like member receivable in said one of said outwardly protruded and inwardly recessed sections to release the vacuum therein.