DESCRIPTION TECHNICAL FIELD This invention relates generally to dispensers for water and other liquids, and more specifically to an improved thermoelectric cooling method and apparatus for use with water dispensers. BACKGROUND ART Water dispensers are well known and in widespread use. Most known water dispensers simply provide a tap to a potable water line or a replaceable bottle of water that selectively delivers a flow of room- temperature (uncooled) water through a valve to the consumer. Other water dispenser systems provide heating and/or cooling to the water, typically by well-known heat coil and/or refrigeration techniques.

Thermoelectric modules may also be used to cool the water in a water dispenser. However, known thermoelectric module-cooled dispenser techniques simply place the cold side of the thermoelectric module adjacent the water receptacle (e.g., the water bottle), which is an extremely inefficient way to cool the water in the receptacle.

DISCLOSURE OF INVENTION

This invention provides an improved thermoelectric water cooling method and apparatus for use with water dispensers, and can be used with potable water

line or bottled water dispenser systems. The inventive apparatus includes a thermoelectric module having a normally hot side and a normally cold side positioned external to the water containing receptacle, with a heat sink in contact with the module hot side, a fan, and a power supply (for the thermoelectric module and fan) all external to the receptacle. A thermally conductive, finger-like probe contacts the module cold side and penetrates the wall of the water receptacle to extend some distance into the interior volume of the water receptacle where it acts as a cold sink to encourage ice formation. A water-tight seal surrounds the probe and prevents water from escaping the water receptacle.

The cold side of the thermoelectric module is thus not clamped to or otherwise in direct contact with the water receptacle, but rather is in contact with the specially shaped cold sink element which in turn penetrates through the wall of the water receptacle and is submerged into the water. The shape of the cold sink will allow ice to form around the cold sink, thereby storing a large amount of energy in the phase change between water and ice. This energy storage (in the form of ice) is drawn upon when the water cooling requirement is larger than the thermoelectric capacity of cooling, and is replenished when the water cooling requirement is less than the cooling capacity. The shape of the cold sink also allows self regulation of the amount of ice that is formed around the cold sink.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a top plan view in partial cross- section of a thermoelectric cooling for a water dispenser apparatus of this invention, as installed on a wall of a water-containing receptacle, illustrating the operative components external to the receptacle including a thermoelectric module having a normally hot side and a normally cold side, a heat sink in contact with the module hot side, a fan, and a power supply; and the components internal to the receptacle including a finger-like probe in contact with the module cold side and forming a cold sink, and a seal such as a nut and a gasket; and

Fig. 2 is a partially cutaway side elevation view of the thermoelectric cooling for a water dispenser apparatus of Fig. 1 as installed and in operation on the wall of the water-containing receptacle, illustrating the formation of an ice mass on the cold sink.

BEST MODE FOR CARRYING OUT THE INVENTION Fig. 1 is a top plan view in partial cross- section of a thermoelectric cooling for a water dispenser apparatus 10 of this invention, as installed on a wall 12 of a water-containing receptacle 14, illustrating the operative components external to the receptacle including a thermoelectric module 16 having a normally hot side 18 and a normally cold side 20, a heat sink 22 in contact with the module hot side, a fan 24, and a power supply 26. The components internal to the receptacle include a thermally conductive finger-like probe 30 in contact with

the thermoelectric module cold side and forming a cold sink 32, and a water seal 34 such as a nut 36 and a gasket 38.

The thermoelectric module 16 is preferably compressed and clamped (not bonded or soldered) between heat sink 22 and cold sink 32. The heat sink 22 preferably comprises fins of extruded aluminum, and may be serrated or otherwise shaped to enhance heat exchange efficiency. The heat sink 22 is preferably offset from the fan 24 by one or more spacers 40.

Fig. 2 is a partially cutaway side elevation view of the thermoelectric cooling for a water dispenser apparatus 10 of Fig. 1 as installed and in operation on the wall 12 of the water-containing receptacle 14, illustrating the formation of an ice mass 42 on the cold sink 32. The probe 30 is preferably cylindrical in shape, for ease in construction and operation, and for efficiency in the water/ice phase changes. The probe should be of a size to extend well into the water receptacle, to enable sufficient water contact and ice formation.

While this invention has been described in connection with preferred embodiments thereof, it is obvious that modifications and changes therein may be made by those skilled in the art to which it pertains without departing from the spirit and scope of the invention.

Accordingly, the scope of this invention is to be limited only by the appended claims.