1. Field of the Invention
The present invention relates generally to warmers for warming consumable liquids, such as coffee, and for controllably maintaining the elevated temperature of the liquid. More particularly, the invention concerns a warmer for warming consumable liquids and for maintaining the temperature of the liquid at one of three temperatures selected by the user.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
Beverages such as coffee, tea and the like are best enjoyed when consumed hot. When such beverages are served in a conventional drinking cup they tend to cool relatively rapidly. This is particularly true when the beverage is served in a paper drinking cup of the character used in many drive-through restaurants.
Devices of several different designs have been suggested in the past for warming consumable liquids and for maintaining the elevated temperature of the liquid. Exemplary of one such device is that described in U.S. Pat. No. 6,121,585 to Dam. The invention described in the Dam patent comprises a beverage cup and cup holder system. The Dam beverage cup includes a sleeve, a liner and a base that includes a plate, a heating element and a pair of spring terminals. The base further includes a contact ring and a contact disk. The cup holder, which is adapted to mate with the base of the beverage cup, has recessed land areas which lie below a plane of the support for the beverage cup and are electrically isolated from each other. The cup holder includes spring contacts which extend into the recessed land areas and are adapted to receive connections from an external source of electrical current. The beverage cup, when filled with a hot beverage, is placed into the cup holder. As the beverage cup is placed into the cup holder, the contact disk and contact ring automatically align with the recessed land areas and make contact with the spring contacts. The heating element of the device maintains a beverage at a desirable equilibrium temperature for an extended period of time.
Another prior art device past for warming consumable liquids is described in U.S. Pat. No. 4,463,664 issued to Peace. The Peace invention provides a receptacle having a thermally nonconductive exterior to retain the heat of liquids, and a durable heat-conductive interior portion to reside in heat-conductive relation with a source of warming heat, so as to impart heat to the contents of the receptacle. The receptacle of the Peace device comprises a heat-conductive liner including a bottom portion and an upwardly extending wall portion, and a heat-insulating sleeve surrounding the wall portion of the liner, the bottom portion of the liner being exposed for direct contact with a heat source. The nonconductive sleeve surrounding the wall portion of the conductive liner has an open bottom which terminates a short distance below the bottom portion of the liner in surrounding yet spaced-apart relation to the bottom portion, in order to isolate the sleeve from the heat source.