1. Field of the Invention
The present invention relates to an attachment which can discharge carbon dioxide into a conventional beverage container.
2. Description of Related Art
Soft drinks are typically carbonated with carbon dioxide (CO.sub.2) to improve the taste of the beverage. The soft drink is then bottled in a pressurized sealed container to maintain the drink in the carbonated state. Carbonated soft drinks are frequently sold in two liter plastic bottles which have a resealable top. Removing the top allows the CO.sub.2 to flow out of the container. Repeated openings of the top will allow a significant amount of the carbon dioxide to escape, resulting in a soft drink that taste "flat". It is desirable to recharge the soda with a CO.sub.2 cartridge or tank to extend the useful life of the soft drink.
U.S. Pat. No. 5,022,565 issued to Sturman et al, discloses a dispenser which can be attached to the top of a beverage container to discharge CO.sub.2 into the contents of the container. The Sturman dispenser includes a small removable CO.sub.2 cartridge and a pressure regulator which regulates the internal pressure of the container. The dispenser of the '565 patent also contains an outlet tube and a spring loaded lever valve which controls the flow of soda out of the container.
The regulator valve of the Sturman dispenser is constructed so that CO.sub.2 flows from the cartridge to the beverage container until the pressure within the container reaches a predetermined level. The container pressure is a fixed value which is set by the area ratio between a valve port and a valve member that controls the movement of the regulator valve. Each beverage container is therefore charged to approximately the same pressure. It would be desirable to provide a soft drink dispenser which would allow the user to vary the pressure level at which the dispenser charges the soft drink with CO.sub.2. For example, the user may want to carbonate an uncarbonated drink. Carbonating an uncarbonated soft drink will typically require a greater amount of CO.sub.2 and a higher beverage pressure than a soft drink which has lost some of its carbonation.