Water heating system for a dishwasher

Claim 2

A dishwasher including walls enclosing a dishwashing chamber and defining an access opening, a door for enclosing said dishwashing chamber, means for spraying in said chamber, means for supporting dishes in exposed relationship to said spray means, one of said walls forming a sump below said support means, a regenerative pump assembly having an inlet fluidly connected to said sump and an outlet fluidly connected to a valve, said pump having a housing enclosing a circular channel between said pump inlet and said pump outlet; an impeller rotated within said pump housing by an electric drive motor, said impeller having a plurality of turbine buckets formed along its peripheral edge which are movable through said circular channel as said impeller rotates for passing fluid between said inlet and said outlet and for heating the fluid in said annular channel by the impact of said moving buckets upon the fluid; said valve having outlets operative in response to control means for circulating fluid flow from said pump outlet to said spray means and to said sump for return to said pump; said valve sump outlet being in the form of a restricted passage to throttle its discharge whereby upon said control means causing said pump outlet to be connected to said restricted passage to increase the amount of work expended by said pump upon the fluid in said pump thereby raising the temperature of the fluid in said buckets before its recirculation to said sump.

Claim 3

A dishwasher comprising: a casing defining a washing chamber having a sump and an access opening; a door for enclosing said dishwashing chamber, means for spraying in said chamber, means for supporting dishes in exposed relationship to said spray means, one of said walls forming a sump below said support means, electrical heating means in said sump; a regenerative pump assembly having an inlet fluidly connected to said sump and an outlet fluidly connected to a three-way valve; said pump having a housing enclosing a circular channel between said pump inlet and said pump outlet; an impeller rotated within said pump housing by an electric drive motor, said impeller having a plurality of turbine buckets formed along its peripheral edge which are movable through said circular channel as said impeller rotates for passing water between said inlet and said outlet and for heating the water in said annular channel by the impact of said moving buckets upon the water; said three-way valve being movable by control means to a spray outlet, a sump heating outlet and a drain outlet for directing water flow from said pump to said spray means, to said sump and to said drain, respectively, whereby the water directed to said spray means and said sump is recirculated to said pump inlet; said valve sump heating outlet having a restricted passage such that upon said valve sump heating outlet being connected to said pump outlet the work expended by said pump upon the water is increased from a first level to a second higher level; said control means including a control circuit for said dishwasher having timer means for sequentially deenergizing and energizing said pump drive motor during periods of fill and wash; manually operated preselectable water heating means in said control circuit operative for deenergizing said timer motor, energizing said pump drive motor and moving said valve heating outlet in communication with said pump outlet so as to increase the amount of work expended by said pump upon the water in said pump thereby raising the temperature of the water in said buckets before its exit through said restricted passage to said sump.

Claim 4

A dishwasher comprising: a casing defining a washing chamber having a sump and an access opening; a door for enclosing said dishwashing chamber, means for spraying in said chamber, means for supporting dishes in exposed relationship to said spray means, one of said walls forming a sump below said support means, electrical heating means in said sump; a regenerative pump assembly having an inlet fluidly connected to said sump and an outlet fluidly connected to a three-way valve; said pump having a housing enclosing a circular channel between said pump inlet and said pump outlet; an impeller rotated within said pump housing by an electric drive motor, said impeller having a plurality of turbine buckets formed along its peripheral edge which are movable through said circular channel as said impeller rotates for passing water between said inlet and said outlet and for heating the water in said annular channel by the impact of said moving buckets upon the water; said three-way valve being movable by control means to a spray outlet, a sump heating outlet and a drain outlet for directing water flow from said pump to said spray means, to said sump and to said drain, respectively, whereby the water directed to said spray means and said sump is recirculated to said pump inlet; said valve sump heating outlet having a restricted passage such that upon said valve sump heating outlet being connected to said pump outlet the work expended by said pump upon the water is increased from a first level to a second higher level; said control means including a control circuit for said dishwasher having timer means for sequentially deenergizing and energizing said pump drive motor during periods of fill and wash; manually operated preselectable water heating means in said control circuit operative for deenergizing said timer motor, energizing said pump drive motor and moving said valve heating outlet in communication with said pump outlet so as to increase the amount of work expended by said pump upon the water in said pump thereby raising the temperature of the water in said buckets before its exit through said restricted passage to said sump.

Claim 5

A dishwasher including walls enclosing a dishwashing chamber and defining an access opening, a door for enclosing said dishwashing chamber, means for spraying in said chamber, means for supporting dishes in exposed relationship to said spray means, one of said walls forming a sump below said support means, electrical heating means in said sump; a pump assembly having an inlet fluidly connected to said sump and an outlet fluidly connected to a three-way rotating stem valve; said stem being biased to a spray position directing water through a valve spray outlet to said spray means, said stem being rotatable in response to first and second solenoids to a heating position and a drain position directing water respectively through a valve sump outlet to said sump and through a drain outlet to said drain; said pump having a housing enclosing a circular channel between said pump inlet and said pump outlet; an impeller rotated within said pump housing by an electric drive motor, said impeller having a plurality of turbine buckets formed along its peripheral edge which are movable through said circular channel as said impeller rotates for passing water between said inlet and said outlet and for heating the water in said annular channel by the impact of said moving buckets upon the water; said valve sump outlet having a restricted passage whereby upon said valve stem being moved directing flow through said restricted passage the water in said pump housing is increased in temperature by the work in its buckets on the water to produce a heating of the water in said sump, a control circuit for said dishwasher including a timer motor and control switch for sequentially controlling a fill, wash and rinse cycle for said dishwasher, a preselectable manually operated heating selector switch in said control circuit operative upon the completion of said fill period to open timer switch means thereby deenergizing said timer motor while energizing said drive motor and said electrical heater, said control circuit operative to energize said first solenoid moving said valve stem to its heating position; a thermostat in said dishwashing chamber operative upon sensing a predetermined water temperature in said sump to close contact means in said circuit to restart said time motor and initiate said wash cycle; and whereby upon said valve sump outlet restricted passage being connected to said pump to increase the amount of work expended by said pump upon the water in said pump housing together with said electrical heating means raising the temperature of the water in said sump to said predetermined temperature.

Claim 6

A dishwasher including walls enclosing a dishwashing chamber and defining an access opening, a door for enclosing said dishwashing chamber, means for spraying in said chamber, means for supporting dishes in exposed relationship to said spray means, one of said walls forming a sump below said support means, electrical heating means in said sump; a pump assembly having an inlet fluidly connected to said sump and an outlet fluidly connected to a three-way rotating stem valve; said stem being biased to a spray position directing water through a valve spray outlet to said spray means, said stem being rotatable in response to first and second solenoids to a heating position and a drain position directing water respectively through a valve sump outlet to said sump and through a drain outlet to said drain; said pump having a housing enclosing a circular channel between said pump inlet and said pump outlet; an impeller rotated within said pump housing by an electric drive motor, said impeller having a plurality of turbine buckets formed along its peripheral edge which are movable through said circular channel as said impeller rotates for passing water between said inlet and said outlet and for heating the water in said annular channel by the impact of said moving buckets upon the water; said valve sump outlet having a restricted passage whereby upon said valve stem being moved directing flow through said restricted passage the water in said pump housing is increased in temperature by the work in its buckets on the water to produce a heating of the water in said sump, a control circuit for said dishwasher including a timer motor and control switch for sequentially controlling a fill, wash and rinse cycle for said dishwasher, a preselectable manually operated heating selector switch in said control circuit operative upon the completion of said fill period to open timer switch means thereby deenergizing said timer motor while energizing said drive motor and said electrical heater, said control circuit operative to energize said first solenoid moving said valve stem to its heating position; a thermostat in said dishwashing chamber operative upon sensing a predetermined water temperature in said sump to close contact means in said circuit to restart said time motor and initiate said wash cycle; and whereby upon said valve sump outlet restricted passage being connected to said pump to increase the amount of work expended by said pump upon the water in said pump housing together with said electrical heating means raising the temperature of the water in said sump to said predetermined temperature.