Abstract:
A system for enabling the efficient evacuation of air within a food container. A bellows-enabled lid fits into a respective container in an air-tight relationship. A bellows mechanism having plural resilient members and dual one-way valves provides efficient manual operation and resulting air evacuation from the container interior. A lid-mounted release valve with associated resilient member enables efficient release of vacuum conditions within the container. Plural ornamental configurations of the container with associated bellows-enabled lid are illustrated.

Description:
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0001]    N/A 
       BACKGROUND OF THE INVENTION 
       [0002]    It is generally known that harvested or prepared food can be kept in a palatable, edible condition longer if stored in an enclosure that inhibits entry and/or circulation of air across the surface of the food. In a simple form, plastic containers having interference-fit lids partially achieve this goal at very low cost. Rigid containers having threads adjacent an opening for receiving a counter-threaded lid are also well known, such as glass jars having metal, threaded lids. Further still, rigid containers may be provided with sealing lids that are otherwise forced onto or clamped against the opening of the container, such as through the use of an external spring clamp or other deformable member. Yet while all such mechanisms prevent the flow of air into or out of a container, they also serve to seal a certain quantity of air within the container itself. 
         [0003]    For many years, people have practiced the food preservation technique known as canning in which the food to be stored and the respective container are raised to an elevated temperature before an airtight lid is secured against the container opening. It is often recommended that for best results, as much of the container&#39;s interior space should be taken up by the food to be preserved, thus displacing air within the container itself. An airtight seal is thus achieved, but only through significant effort, employment of heating means such as a large water bath, racks or stands for retaining the containers within the heated bath, and scrupulously cleaned containers and lids, and use of great care and patience. While sealing the container and its contents at an elevated temperature results in a slight vacuum under the respective lid once the container and contents are cooled, the effort and logistics required are substantial and absent proper technique spoilage may still occur. 
         [0004]    A more simple and effective technique has been identified for food storage. A lid, configured for air-tight sealing of a respective container, is provided with a hand-operated bellows mechanism for evacuating a significant amount of air from the closed container. To achieve such vacuum conditions, the bellows mechanism includes a first one-way valve for enabling air to flow out of the bellows and into the surrounding atmosphere when the bellows is compressed by manual depression of an upper contact surface. Once fully compressed and manual pressure is released, the bellows retracts upward through the force of a resilient member such as a spring. This creates a lower pressure state compared to that within the container itself. A second one-way valve associated with the bellows lid allows air from within the container to flow into the bellows until pressure is equalized. This process is repeated until the pressure within the container is lowered to a point where it is equal to that within the bellows. 
         [0005]    Prior art bellows have typically employed a central, axially disposed spring. Such an arrangement, however, is susceptible to frictional interference between the bellows and the lid frame surrounding the bellows when an off-axis component of compressive force is non-negligible. This can be frustrating to a user who perceives a greater amount of force is required to achieve evacuation of the food container than would otherwise be required. This could lead to excessive application of force which may result in breakage of the bellows mechanism. 
         [0006]    A further deficiency associated with prior art bellows-enabled container lids is the mechanism for releasing the vacuum state within the container. In a simplest approach, the prior art has employed a projecting member with a knob or other grippable member. The member acts as a manually actuatable valve. A user is required to grip or grasp the knob and pull against the force of the vacuum pressure until a sealing member is disengaged and air is allowed to rush into the container. Such an embodiment may also utilize a resilient member or members such as a spring surrounding the projecting member for urging the sealing member into a sealing position. In that such containers may be employed in wet or oily environments where food is being prepared, grasping such a projecting member and pulling with sufficient force to overcome the vacuum in the container may be difficult. 
         [0007]    Alternative techniques for vacuum release have employed complex rotatable arms or levers which translate rotational movement into linear movement, including depression of a one-way valve. The complexity associated with such prior art approaches increases cost, likelihood of material failure, and potential for contamination. 
         [0008]    What is lacking in the art is a simple bellows-enabled lid for vacuum sealing a food container, the bellows enabling easy and reliable use even with off-axis manual pressure, and having a simplified vacuum release mechanism that can be operated even in wet or oily environments. 
       BRIEF SUMMARY OF THE INVENTION 
       [0009]    Disclosed is a system and method for enabling the reliable and selective vacuum sealing of a food container. A bellows-equipped container lid is configured to be snuggly received within a respective container. The lid is provided with a manually operated bellows having at least two one-way valves. In order to function even when manual pressure is applied off-axis, the bellows is provided with plural, and preferably four, resilient members such as compression coil springs disposed about a bellows pressure plate. To enable simple pressure equalization of the container interior with the surrounding atmosphere, a further one-way valve is provided in the container lid adjacent the bellows. This valve is provided with a resilient member, such as a spring, that is sufficiently resistant to compression such that it can prevent movement of the respective valve even when the food container is under vacuum. The valve is only opened once a user applies pressure to the valve member, such as by pushing a finger downward on the valve member, overcoming the resilient member resistance. The negative pressure within the container is thus released and the lid may be removed. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0010]    Embodiments of the present invention may be better understood by referring to the following description in conjunction with the accompanying drawings in which: 
           [0011]      FIGS. 1A-1G  illustrate a first embodiment of a rectangular container with a bellows-equipped lid according to the presently disclosed invention; 
           [0012]      FIGS. 2A-2G  illustrate a first embodiment of a round container with a bellows-equipped lid according to the presently disclosed invention; 
           [0013]      FIGS. 3A-3G  illustrates a first embodiment of a square container with a bellows-equipped lid according to the presently disclosed invention; 
           [0014]      FIGS. 4A-4G  illustrate a second embodiment of a rectangular container with a bellows-equipped lid according to the presently disclosed invention; 
           [0015]      FIGS. 5A-5G  illustrate a second embodiment of a round container with a bellows-equipped lid according to the presently disclosed invention; 
           [0016]      FIGS. 6A-6G  illustrates a second embodiment of a square container with a bellows-equipped lid according to the presently disclosed invention; 
           [0017]      FIGS. 7A-7G  illustrate a third embodiment of a rectangular container with a bellows-equipped lid according to the presently disclosed invention; 
           [0018]      FIGS. 8A-8G  illustrate a third embodiment of a round container with a bellows-equipped lid according to the presently disclosed invention; 
           [0019]      FIGS. 9A-9G  illustrates a third embodiment of a square container with a bellows-equipped lid according to the presently disclosed invention; 
           [0020]      FIGS. 10A-10G  illustrate a fourth embodiment of a rectangular container with a bellows-equipped lid according to the presently disclosed invention; 
           [0021]      FIGS. 11A-11G  illustrate a fourth embodiment of a round container with a bellows-equipped lid according to the presently disclosed invention; 
           [0022]      FIGS. 12A-12G  illustrates a fourth embodiment of a square container with a bellows-equipped lid according to the presently disclosed invention; 
           [0023]      FIG. 13  is an exploded, perspective view of a rectangular container with a bellows-equipped lid, similar to the embodiment of  FIGS. 1A-1G , according to the presently disclosed invention; 
           [0024]      FIG. 14A  is a cut-away perspective view of the container and lid of  FIG. 13  prior to actuation of the bellows; 
           [0025]      FIG. 14B  is a perspective view of the container and lid of  FIG. 13  prior to actuation of the bellows; 
           [0026]      FIG. 15A  is a cut-away perspective view of the container and lid of  FIG. 13  after actuation of the bellows; 
           [0027]      FIG. 15B  is a perspective view of the container and lid of  FIG. 13  after actuation of the bellows; 
           [0028]      FIG. 16A  is a sectional elevation view of a container disposed on top of and nesting with the bellows-equipped lid of another container, such as illustrated in the embodiment of  FIGS. 1A-1G ; and 
           [0029]      FIG. 16B  is a close-up view of the portion of  FIG. 16A  enclosed in a dashed-line circle. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0030]    Depicted in  FIGS. 1A through 12G  are various embodiments of containers with bellows-equipped lids according to the presently disclosed invention. The containers, as depicted and when viewed from above or below, may take the shape of a rectangle, circle, or square. Alternatively, while not depicted, other shapes may be utilized. The size of the container and respective lid can depend upon the intended use. The various illustrated containers are sized to hold from approximately 0.5 quarts to 3.5 quarts, though the depicted configurations can be adapted to a wide range of volumes. Dry, moist or liquid contents can be retained therein. 
         [0031]    The container itself may be provided in one of a variety of materials, depending upon the intended application and market. The container must be of sufficient rigidity to resist deforming while under internal vacuum conditions, and to enable multiple containers to be vertically stacked, as discussed with respect to  FIGS. 16A and 16B . Further, translucent or transparent materials may be desired to enable a user to visually ascertain the type and amount of contents within a container without the need to open the respective lid. However, opaque materials may be employed, such as in the case of retaining photosensitive materials. Various color tints may also be employed for aesthetic or design reasons. The container surface may be smooth and reflective, which may enable easy cleaning. However, in certain applications, a matte finish may be preferred. Various labels or artistic decorations may be applied to the outer surface thereof, and the container itself may be embossed or otherwise imprinted with decorative design or advertising information. Suitable materials for the container include plastics or metals. 
         [0032]    While the depicted lids have a shape, viewed from above or below, that compliments the opening or mouth of the respective container, the fundamental components and operative nature of each lid is the same. With reference to  FIGS. 13, 14A and 14B , a rectangular lid assembly  10  is shown, though the following description is applicable to all of the lids illustrated in  FIGS. 1A through 12G . Starting from the upper surface of the lid assembly, an upper cover  12  has a bellows aperture  29  for receiving a bellows plate  16  therein. Disposed within the bellows plate is a first one-way valve  14  used to evacuate air from a pump chamber into the atmosphere as the bellows plate is manually depressed relative to the upper cover. Overlying the one-way valve is a vented cover plate  15 . The cover plate is provided with a plurality of vent holes dimensioned to enable air to pass therethrough unimpeded while at the same time inhibiting the introduction of particulates that could otherwise interfere with the operation of the one-way valve. 
         [0033]    A lower peripheral surface of the bellows plate  16  is in air-tight contact with a bellows  18 , which in turn has a lower peripheral surface in contact with a sealing ring  26 . The sealing ring is disposed on a floor surface  33  within a cavity  31  formed within a lower cover  32  such that a pump chamber is formed between the bellows plate, bellows, sealing ring, and lower cover cavity floor surface. The cavity is defined by the floor surface and vertically extending walls  41  projecting upwardly from the floor surface. An upper extent of the vertically extending walls sealingly mates with a lower peripheral edge of the upper cover  12  defining the bellows aperture  29 . 
         [0034]    In the pump chamber, through the lower cavity floor surface, is a second one-way valve  30  having an associated perforated valve cover  34 . The perforations in the valve cover enable air to flow through the second one-way valve. Disposed between the perforated valve cover and the second one-way valve is a waterproof diaphragm  35  formed of a disc of plastic porous material having a porosity selected to enable the flow of gaseous molecules therethrough but to inhibit the flow of liquids. Thus, the diaphragm inhibits the flow of liquid into the bellows or pump chamber. A thickened ring of material is formed on the peripheral edge of the diaphragm to enable a secure fluid-proof seal between the perforated valve cover and the second one-way valve. The second valve is used to evacuate air from within the container beneath the lid assembly into the pump chamber after the bellows plate has been manually depressed and released as the resilient members urge the bellows plate upward in the absence of manual compression. 
         [0035]    Also within the pump chamber are a plurality of resilient members  28 , such as compression coil springs, each oriented to have a substantially vertical axis of symmetry and travel. As illustrated, four springs are employed. Each is radially displaced from a vertical axis of symmetry of the lid assembly  10 . Preferably, the radial displacements are equal in length. The springs are in contact with an underside of the bellows plate  16  and the lower cover cavity floor surface  33 . Physical features formed on or in the underside of the bellows plate and/or on or in the cavity floor surface. As illustrated examples of such features, each spring is retained in place with respect to the bellows plate by a downwardly projecting post  39  and with respect to the cavity floor surface by an upwardly projecting socket  37 . Other resilient members, such as leaf springs, can also be used, and some number other than four resilient members can be employed, though three is a preferred minimum number. Radially displacing the resilient members enables smooth vertical translation of the bellows plate even when pressure is applied at an angle to the vertical axis. 
         [0036]    Disposed within and extending through the upper cover  12  and the lower cover  32  is a release valve  20  and associated resilient member  22  and sealing ring  24 . The release valve is employed to selectively release the vacuum within a sealed container. A user manually depresses the release valve in a downward direction, against the resisting force of the respective spring  22 , thus temporarily creating a physical space between the sealing ring on the lower extent of the release valve and the surrounding portion of the lower cover, allowing air from the surrounding atmosphere to enter the container beneath the lid assembly, thereby facilitating removal of the lid assembly  10 . In one embodiment, the upper end of the release valve and the upper cover do not form an airtight seal. 
         [0037]    The lid assembly  10  further comprises a peripheral interface seal  36  about the lower cover  32  that enables creation of an airtight seal between the lid assembly and the respective container  38  when installed therein. The interface seal may be provided with or comprised of one or more resilient rings of deformable material that facilitate the airtight seating of the lid assembly within the container opening. 
         [0038]    In  FIGS. 14A and 14B , the lid assembly  10  is disposed in the respective container  38  but the bellows plate  16  has not yet been manually operated by a user. 
         [0039]    In  FIGS. 15A and 15B , a user has pressed down upon or compressed the bellows plate  16 , against the resistive force of the plural resilient members  28 , at least once. As the bellows plate is pressed down within the cavity  31  of the lower cover  32 , air within the pump chamber is compressed and the internal pressure becomes greater than that in the surrounding atmosphere. As a result, the first one-way valve  14  is temporarily forced open and air within the pump chamber is evacuated. As depicted, the first and second one-way valves  14 ,  30  each interface to the respective surrounding surface via a deformable ring of pliant material. With respect to the first one-way valve, the valve is urged into a closed position by the pliant ring. However, when the pump chamber internal pressure rises upon bellows plate depression, the valve rises with respect to the pliant ring and internal air is released. 
         [0040]    When a user ceases applying downward pressure on the bellows plate, the resilient members  28  urge the bellows plate  16  upward. The pump chamber air pressure is thus lowered with respect to the air pressure within the container. This forces the second one-way valve  30  to move upward against the resistive force of the respective pliant ring, thereby allowing air from within the container to flow through the perorated valve cover  34  and diaphragm  35  and into the pump chamber. The user again actuates the bellows plate downward, evacuating air from the pump chamber into the atmosphere, then releases the bellows plate, thereby evacuating air form the container into the pump chamber. The process is preferably repeated until the air pressure within the pump chamber with the bellows plate fully depressed is substantially equivalent to the container internal air pressure. Under this condition, the air pressure within the container and pump chamber is significantly less than that of the surrounding atmosphere. This negative pressure draws the bellows plate  16  down against the resilient members  28 , as shown in  FIGS. 15A and 15B . 
         [0041]    To enable removal of the lid assembly  10  once vacuum conditions exist within the container, a user depresses the release valve  20 , against the resistive force of the respective spring  22 , thereby creating a space between the sealing ring  24  and the lower cover  32 , enabling atmospheric air to flow into the container and releasing the vacuum condition therein. As pressure rises in the container, the second one-way valve  30  is forced open, against the urging of the respective pliant ring, allowing pressure within the container and within the pump chamber to equalize, and allowing the bellows plate  16  to rise. This configuration enables simple and reliable vacuum release, even when a user has wet or oily fingers. 
         [0042]    A convenient feature of the illustrated lid assembly  10  is a gently curved and depressed region  40  formed in the bellows plate  16 . Depending upon the dimensions of the lid assembly, this depressed region may be sized to comfortably receive three fingertips of an average adult. The slight downward curvature helps align the downward pressure applied by the fingertips of a user towards the vertical axis, thereby enabling more efficient operation of the bellows. In combination with the plural, and preferably four, resilient members  28 , the bellows plate  16  is maintained is a substantially orthogonal, or horizontal, plane with respect to the substantially vertical axis of bellows plate movement. This reduces the friction between the bellows plate and the surrounding bellows enclosure  31  that would otherwise resist bellows plate movement were there to be only one centrally disposed spring between the bellows plate and the bottom of the bellows enclosure. The depressed region can also assume other shapes that help center and align the downward force applied by a user to the bellows plate, depending upon the size of the bellows plate and other factors. 
         [0043]      FIGS. 16A and 16B  illustrate a convenient feature of the presently disclosed bellows-enabled lid and container.  FIG. 16B  is a close-up, cut-away view of an upper container  38  lower extent and lid upper cover  12  shown in a dashed circle in  FIG. 16A . As is evident in  FIG. 16B , the container lower extent is provided with a profile that compliments the upper surface of the upper cover. While various configurations may be employed, as illustrated, the container is provided with a slight downward projection or bead  42  that may be continuous around the lower edge of the respective container. This projection is received within a ridge  44  formed about the outer lateral edge of the lid cover. These complimentary features help keep vertically stacked containers in alignment and resist relative horizontal movement that could result in the toppling of one or both containers. As a further benefit, the downward projection beneath the container eliminates the presence of a continuous flat lower surface that could otherwise be prone to adhesion to a wet surface such as a kitchen counter and to the buildup of mold therebetween. 
         [0044]    Many changes in the details, materials, and arrangement of parts and steps, herein described and illustrated, can be made by those skilled in the art in light of teachings contained hereinabove. Accordingly, it will be understood that the following claims are not to be limited to the embodiments disclosed herein and can include practices other than those specifically described, and are to be interpreted as broadly as allowed under the law.