Hot beverage makers, such as coffee makers, have been known and sold for many years using various brewing techniques. The typical and traditional coffee maker includes a stand or tower that has a warming plate forming the bottom or base of the tower with a filter basket located above the warming plate. The interior of the tower defines, at least in part, a fresh water reservoir. Such coffee makers further include a fluid reservoir, such as a glass carafe, that rests on the warming plate beneath the filter basket. Alternatively, the fluid reservoir may be an insulated carafe, in which case the warming plate is typically omitted.
In use, an operator fills the carafe in order to transfer water to the fresh water reservoir. The water is heated and passed through the filter basket, which includes the grounds to be infused. The brewed beverage then flows from the basket into the carafe. The beverage is maintained at an elevated temperature via the warming plate upon which the carafe rests, in the case of a glass carafe, or by the insulating properties of the carafe in the case of an insulated carafe.
A new variation of coffee maker has been developed wherein a brewed beverage tank is included, such as the coffee makers described in commonly assigned U.S. Pat. No. 6,564,975 to Garman, issued May 20, 2003, and U.S. Pat. No. 6,681,960 to Garman, issued Jan. 27, 2004, the contents of which are incorporated herein in their entirety. Briefly, the brewed beverage tank holds the filter basket above a reservoir portion. Hot water passes through the filter basket and a material to be infused (e.g., ground coffee beans). The brewed beverage is then collected and held in the reservoir portion of the brewed beverage tank (“brew tank”). A dispenser actuator is depressed that opens an outlet port in the reservoir. A user simply actuates the dispenser actuator with a mug or cup and the brewed beverage passes through the outlet to the operator's container.
In order to allow a user to determine the amount of brewed coffee within the device, a transparent window on the coffee holding reservoir can be used. A transparent vertical slot-type window on the side of the holding reservoir can also be used. Also known is the use of a buoyant ball contained within a transparent column, the transparent column containing coffee at the same level as in the holding reservoir and the ball floating on the surface of the coffee in the column. The transparent column typically includes markings that correspond to the quantity of coffee in the reservoir, such that the quantity of coffee in the reservoir may be determined by reading the marking nearest the floating ball.
However, these transparent windows, slots, and columns give a somewhat rough estimate of how much coffee remains and often do not give a clear indication of the exact amount. In addition, the amount of coffee remaining in the coffee maker is often difficult to gauge as the coffee may be difficult to see against the background of the coffee maker which is often somewhat similar in color to the coffee itself. Further, the glass or plastic of the these transparent windows, slots, and columns may be quickly stained by the coffee, such that the transparency is greatly reduced and the amount of coffee becomes difficult or impossible to determine. Because of the above problems, even when the amount of coffee may be determined at a short distance from the coffee maker via these transparent windows, slots, and columns, it may be difficult or impossible to determine the amount of coffee at a greater distance, such as across a room.
There is a need, therefore, for a coffee level indicator that is accurate, reliable, clearly indicates the amount of brewed coffee remaining in the holding reservoir, is unaffected by staining, and is readable at a distance. The operation and structure of a brew tank with an integrated fluid gauge in accordance with the present invention would solve one or more of these or other needs.