Product preserving stopper
BACKGROUND OF THE INVENTION 
     Many beverages, in particular wine, are sensitive to the presence of oxygen. Wine bottles are often filled with an inert gas, such as nitrogen, before filling with wine so that the space between the wine and the cork contains virtually no oxygen. The amount of oxygen which may seep through the cork is usually small enough so as not to be a problem. 
     The greatest problem of oxygen in a wine bottle usually arises after a wine bottle has been opened, some of the wine has been consumed and the remainder has been stored for one or more days. One way to reduce this problem is by injecting nitrogen into the space above the wine and then quickly recorking or otherwise resealing the bottle. This of course is only as effective as the seal provided by the cork and the effectiveness of purging the wine bottle of oxygen. Another scheme for reducing the harmful effects of oxygen in an open bottle of wine places the interior of the wine bottle at a partial vacuum. This of course only removes part of the air, of which about twenty-percent is oxygen, and so does not solve the problem, especially for oxygen sensitive wines, such as many white wines. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a product preserving stopper, particularly useful for preserving wines and other oxygen-sensitive beverages, which continuously removes oxygen from the interior of the container so to preserve the product. 
     The stopper has a body, a portion of which is sized to seal the opening of the container. A metal-air primary cell, typically a zinc-air primary cell, is mounted to the stopper body. The cell is of the type which has openings, to allow oxygen, typically as a constituent of air, to contact the cell&#39;s cathode to produce an electrical potential between the anode and the cathode of the cell. As is conventional, the anode is electrically connected to an anode can and the cathode is electrically connected to a cathode can. The cell is positioned so that the openings leading to the cathode are in fluid communication with the interior of the container. 
     An electrical conductor is used to connect the anode and the cathode so that the battery discharges until all the oxygen within the container is removed. Preferably the electrical connector is movable so that electrical connection between the anode and cathode occurs only when the user wishes to place the stopper into service. In the preferred embodiment this is achieved by placing a removable separator tab between one end of the electrical connector and the anode can thus isolating the anode and cathode until the tab is pulled from the stopper allowing the electrical connector to contact the anode thus activating the cell. 
     Other features and advantages will appear from the following descriptions in which the preferred embodiment has been set forth in detail in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded partial cross-sectional view of a beverage preserving stopper shown in conjunction with a neck of a bottle. 
     FIG. 2 is a side view similar to that of FIG. 1 but in an assembled condition. 
     FIG. 3 is a side view of the stopper of FIG. 1 shown housed within a retail sales package. 
     FIG. 4 is a plan view of the stopper and package of FIG. 3. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to FIGS. 1 and 2, a beverage preserving stopper 2 is seen to include a stopper body 4 having a stopper base 6 and a stopper lid 8, the lid being heat sealed, or otherwise attached, to an upper surface 10 of base 6. Lid 8 and base 6 have corresponding circular ridges and grooves 12, 14 to aid proper positioning of lid 8 onto base 6. Base 6 has a central bore 16, including upper and lower portions 18, 20 with a shoulder 22 at the junction therebetween. 
     Enlarged upper portion 18 houses an oxygen removing assembly 24. Assembly 24 includes an oxygen permeable hydrophobic layer 25 which is heat sealed to shoulder 22. Layer 25 permits air, in particular oxygen, to pass from lower portion 20, and thus from the interior 26 of bottle 28, into upper portion 18. Layer 25 may be made of polyethylene, polypropylene or PTFE, as well as other materials. One such material is sold under the trademark POREX by Porex Technologies Corp. of Fairburn, Ga. Adjacent hydrophobic layer 25 is a hydrophilic layer 30 to attract any liquids while allowing oxygen to pass to the metal-air primary cell 32 directly above layer 30. Layer 30 may be a 100% cotton mat sold under the trademark WEBRIL by Kendall Company of Walpole, Mass. Hydrophilic layer 30 not only will absorb moisture which may pass hydrophobic layer 26 but also any leakage from the metal-air cell 32, located above layer 30, which may occur. 
     Cell 32 is preferably a zinc-air primary cell of conventional design, such as that made by Duracell of Bethel, Conn. Cell 32 includes a cathode can 34 and an anode can 36 electrically isolated from cathode can 34. Cathode can 34 has a number of openings (not shown) in its surface 38 which face hydrophilic layer 30 to permit oxygen to enter cell 32. An L-shaped resilient contact 40 has a first leg 42 which is positioned for placement between cathode can 34 and an undercut 44 within in the circumferential wall 46 bounding upper portion 18 of central bore 16. A removable separator tab 48 is positioned between a second leg 50 of resilient contact 40 and anode can 36 to interrupt the electrical path which is otherwise created by resilient contact 40 between cathode can and anode can 36. A second hydrophilic layer 52 is used between lid 8 and anode can 36 and acts primarily as a resilient positioner to maintain oxygen removing assembly 24 in position within upper portion 18. 
     A portion 54 of tab 48 extends beyond stopper body 4 by passing through a groove 56 formed in lid 8. This permits the user to remove tab 48 when it is desired to place beverage preserving stopper 2 in service by shorting out anode and cathode cans 34, 36. 
     An O-ring gasket 58 is used to seal the exterior of cathode can 34 and circumferential wall 46. O-ring 58 is located within upper portion 18 of central bore 16 by an O-ring groove 60 formed in circumferential wall 46. Thus, virtually all oxygen which reaches surface 38 of cathode can 34 comes from interior 26 of bottle 28 once stopper 2 is inserted past the mouth 62 of bottle 28 and sealed within the bottle by a series of sealing rings 64. 
     Turning now to FIGS. 3 and 4, stopper 2 is shown contained within an oxygen-impervious retail package 70. Package 70 includes a formed tray 72 heat sealed to a base sheet 74 around their peripheries 76. The outer portion 54 of tab 48 is sealed between tray 72 and sheet 74 at position 78. Stopper 2 is automatically actuated by removing stopper 2 from package 70. 
     Stopper 2 is used primarily to preserve wine within a bottle 28 once the bottle has been opened and some of the wine has been removed. Doing so helps to protect the wine against the adverse affects of oxygen which necessarily enters bottle 28 after the bottle is opened. Upon opening bottle 28 and pouring the desired amount of wine, preferably into a carafe if more than one glass is to be poured, stopper 2 is removed from package 70. Doing so causes tab 48 to be pulled from beneath second leg 50 of contact 40 and anode can 36, thus electrically connecting the two. Inserting shank 78 of stopper body 4 through mouth 62 and into bottle 28 permits cell 32 to remove oxygen from interior 26 of bottle 28. Cell 32 is preferably sized so that oxygen within bottle 28 is removed at a sufficiently rapid pace to prevent the beverage within bottle 28 from becoming oxidized or otherwise spoiling. Cell 32 is also preferably sized so that the beverage with bottle 28 can be consumed a glass at a time. As each glass is removed, the volume of air within bottle 28 increases and the oxygen within the bottle is replenished. It has been found that a commercially available zinc air cell having a rating of about 1000 milliampere hours can effectively preserve the beverage in a 750 milliliter container as the beverage is removed in 125 milliliter increments. 
     The preferred embodiment is not particularly designed for reuse. However, by making stopper lid 8 removable, commercially available metal-air primary cells 32 could be removed and replaced by simply removing the stopper lid 8, the hydrophilic layer 52, the resilient contact 40 and the cell 32 and replacing cell 32 with a fresh cell; the components would then be reassembled for use then (without tab 48) or later (with tab 48 in place). 
     Other modification and variation can be made to the disclosed embodiment without departing from the subject of the invention as defined in the following claims. For example, if desired, contact 40 could be a two-piece element carried by stopper base 6 and stopper lid 8. Other arrangements of hydrophobic and hydrophilic layers 26, 30 could be used, including the use of a second hydrophobic layer between cell 32 and hydrophilic layer 30.