Patent Application
20050244293
The present invention generally relates to containers for storing food items and other perishables and, more specifically, to an improved vacuum canister.
Food, beverages and other perishable items are typically stored in containers such as bottles or canisters. The perishable items stored in such containers, however, deteriorate over time due to air that remains in the container after the container is covered for storage with a lid or cover. The air often contains moisture which further deteriorates the canister contents. Such deterioration may also diminish the natural aroma of the perishable item. In order to prevent such spoilage, it is known to provide vacuum canisters that feature pumps for removing most of the air from the interior of the canister after it is sealed.
In addition to removing air from the interior of the canister, the vacuum assists in maintaining the seal between the canister and the canister lid. As a result, prior art vacuum canisters also typically include a release valve so that the vacuum in the canister may be released prior to removal of the canister lid. In addition to featuring a pump and a vacuum release valve, a number of prior art vacuum canisters feature a vacuum indicator so that the user knows when air has been evacuated from the canister.
An example of a prior art vacuum canister is presented in U.S. Pat. No. 5,692,632 to Hsieh et al. The container of the Hsieh et al. '632 patent includes a lid with a built-in pump. More specifically the lid features a button in its top that, when depressed, forces a piston downwards in a pumping chamber. The piston is connected to the button by a piston rod containing a conduit that leads from the pumping chamber to the exterior of the container. As a result, when the button is pressed down, air below the piston travels out of the pumping chamber through the piston rod conduit to the exterior of the container.
In addition, as the piston of the Hsieh et al. '632 patent moves downward, air from the interior of the container enters the portion of the pumping chamber above the piston through a one-way valve. When the button is released, the piston travels upward due to the force exerted by a compression spring. As the piston travels upward, the air above the piston travels through holes in the periphery of the piston, past an O-ring, to the portion of the pumping chamber below the piston. The downward pumping stroke of the button may then be repeated. The O-ring seals the holes in the periphery of the piston, and also seals the gap between the periphery of the piston and the pumping chamber wall, during the downward pumping stroke so that air may only escape the portion of the pumping chamber below the piston through the piston rod conduit.
While the pumping system of the Hsieh et al. '632 patent works well, the creation of the multiple holes in the periphery of the piston increases manufacturing complexity and costs as does the O-ring seal and the piston rod conduit. In addition, the holes may become clogged or otherwise obstructed which would adversely effect pumping performance. A further disadvantage of the container of the Hsieh et al. '632 patent is that it does not feature a vacuum indicator.
As mentioned previously, a number of prior art vacuum containers provide vacuum indicators. An example of such a container is presented in U.S. Pat. No. 5,803,282 to Chen et al. In addition to including a vacuum pump, the lid features a bellows with an open bottom end that is in communication with the interior of the container. A compression spring is positioned within the bellows and urges the upper end of the bellows upwards out of an aperture formed in the top surface of the lid. As a result, when air has not been evacuated from the container, the upper end of the bellows protrudes up from the top surface of the lid. When air has been evacuated from the container, however, the resulting vacuum pulls the upper end of the bellows down into the aperture so that the presence of the vacuum is indicated to a user.
The container of the Chen et al. '282 patent also includes a vacuum release valve for releasing the vacuum in the container so that the container lid may be easily removed. The valve includes knob which, when pressed downwards, unseats an O-ring so that the interior of the container is permitted to communicate with the surrounding atmosphere through an aperture.
While both the vacuum indicator and release valve of the container of the Chen et al. '282 patent work well, it would be advantageous to combine their functions into a single device. Such an approach would streamline the appearance of the container. In addition, operation of the device would be simplified and more intuitive as users may often instinctively press in on the vacuum indicator of the Chen et al. '282 patent expecting to release the vacuum instead of searching for a separate release valve.
Accordingly, it is an object of the present invention to provide an improved vacuum canister that features a pumping mechanism that is durable and easy to operate.
It is another object of the present invention to provide an improved vacuum canister with a vacuum indicator that indicates when air has been evacuated from the canister.
It is another object of the present invention to provide an improved vacuum canister with a vacuum indicator that also functions as a vacuum release valve.
It is still another object of the present invention to provide an improved vacuum canister that is simple and economical to manufacture.
These and other objects and advantages will be apparent from the following specification.
The present invention is directed to a vacuum canister for storing perishable items. The canister includes a body having an open top and defining a storage space with a lid removably covering the open top of the body. A pump housing is positioned within the lid and defines a pumping chamber that selectively communicates with the atmosphere and the storage space via exhaust and intake passages, respectively, that are formed in the lid. A piston is slidably positioned within the pumping chamber and has a pump handle attached thereto via a piston rod. A compression spring is positioned between the pump housing and the bottom of the piston and urges the piston upward.
A skirt-like piston valve is positioned around the periphery of the piston and seals against the pump housing when the piston is moved downward. Air is permitted to pass between the periphery of the piston and the pump housing when the piston is moved upward. As a result, air is transferred from the storage space to the pumping chamber via the intake passage while air is simultaneously expelled from the pumping chamber to the atmosphere via the exhaust passage as the piston travels downward. A filter and an intake check valve are positioned within the intake passage.
The canister also features a vacuum indicator and release valve that includes a bellows positioned within the lid with an open bottom in communication with the storage space so that the bellows contracts when air is evacuated from the storage space. A compression spring is positioned within the bellows and urges it into the expanded configuration. A button is also positioned in the lid and is slidable between an extended position and a retracted position. A venting passage is formed in the lid between the storage space and the atmosphere with a vacuum release valve positioned therein. A lever is pivotally mounted within the lid and includes a first end attached to the top of the bellows and a second end engaging the release valve and the button so that when the bellows contracts, the lever places the button in the extended position and the vacuum release valve seals the venting passage. Pressing the button when in the extended position opens the vacuum release valve so that the vacuum in the storage space is released through the venting passage.
The following detailed description of embodiments of the invention, taken in conjunction with the appended claims and accompanying drawings, provide a more complete understanding of the nature and scope of the invention.
An embodiment of the improved vacuum canister of the present invention is indicated in general at 10 in
As illustrated in
Positioned between the top and bottom shells of the lid 14 is a pump housing, indicated in general at 32 in
A skirt-like piston valve 38 formed of rubber, flexible plastic or the like is positioned around the periphery of the piston 36 and engages the inner surface 40 cylindrical side wall 42 of the pump housing. More specifically, the skirt-like configuration of the piston valve 38 causes it to seal against the inner surface 40 of side wall 42 when the piston 36 is traveling downward, however, air may pass between the piston valve 38 and the inner surface 40 of the side wall when piston 36 is traveling upward.
A compression spring 52 positioned between the bottom shell 26 of the lid and the bottom 54 of the piston urges piston 36 upward towards the position indicated in phantom at 56. As a result, when handle 16 is pressed, piston 36 travels down from its initial resting position 56 to the position illustrated in
As illustrated in
As illustrated at 76 in
With reference to
The downward travel of piston also causes suction to occur above the piston so that air is withdrawn from the interior storage space 22 of the canister along the path illustrated by arrow 92 in
As described previously, when pump handle 16 is released, piston 36 travels upward to the position illustrated in phantom at 56 in
As a result, repetitive pressing and releasing of the pump handle removes air from the storage space 22 of the canister so that a vacuum is formed. This causes the contents of the canister to remain fresher for an extended period of time and also strengthens the seal between the lid 14 and the canister body.
A vacuum indicator and release valve assembly, indicated in general at 102 in
The end of the lever 104 opposite hook 108 engages button 18 and a valve member 118. Button 18 is slidable between the retracted position illustrated in
The bottom end 132 of the bellows 114 is open and is fitted over a conduit 134 which communicates with the storage space 22 within the canister via a passage 136 and an opening 138 formed in the bottom shell 26. As a result, when air is evacuated from canister storage space 22, it is also withdrawn, as indicated by arrow 142, from the interior of bellows 114 through conduit 134, passage 136 and opening 138. This causes the bellows to contract against the action of spring 116. As a result, the top end 112 of the bellows is lowered so that the lever 104 pivots clockwise.
As lever 104 travels clockwise, the end opposite of the hook end 108 forces button 18 to slide outwards into the position indicated in phantom 122 in
When it is desired to release the vacuum in the canister so that the lid 14 may be removed, button 18 is pressed so that it is returned to the position illustrated in
While the preferred embodiments of the invention have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made therein without departing from the spirit of the invention, the scope of which is defined by the appended claims.
