N/A
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.
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'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.
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.
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.
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.
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.
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.
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.
Embodiments of the present invention may be better understood by referring to the following description in conjunction with the accompanying drawings in which:
Depicted in
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
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
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.
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.
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.
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.
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.
In
In
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
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.
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.
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.
Number | Name | Date | Kind |
---|---|---|---|
2890810 | Rohling | Jun 1959 | A |
3083861 | Amberg | Apr 1963 | A |
5406992 | Miramon | Apr 1995 | A |
5957317 | Lee | Sep 1999 | A |
6044756 | Chang | Apr 2000 | A |
6994227 | Kwon | Feb 2006 | B2 |
Number | Date | Country |
---|---|---|
82 27 597 | Nov 1982 | DE |
94 10 760 | Sep 1994 | DE |
602 25 896 | Apr 2009 | DE |
1 447 037 | Dec 2006 | EP |
Number | Date | Country | |
---|---|---|---|
20160167863 A1 | Jun 2016 | US |
Number | Date | Country | |
---|---|---|---|
62091084 | Dec 2014 | US |