Patent ID: 7931032

Claim:
A dishwasher for residential use, comprising: a housing; a wash chamber enclosed by said housing; a door for accessing said wash chamber; a fluid reservoir disposed in said door for containing fluid which may be used to treat dishes in said wash chamber during a dish cleaning cycle; and a pump disposed in said door for dispensing a predetermined quantity of said fluid from said reservoir into said wash chamber one or more times during said dish cleaning cycle; said pump comprising: a batch chamber having an inlet port; a pumping chamber defined by a reciprocating plunger and having a pumping chamber inlet port; a pumping chamber outlet port; a first check valve in said batch chamber inlet port; and a second check valve in said pumping chamber inlet port; wherein during operation of the dishwasher said fluid flows from said fluid reservoir through said batch chamber inlet port into said batch chamber, then through the pumping chamber inlet port into the pumping chamber, then through the pumping chamber outlet port into the wash chamber, said first and second check valves functioning to prevent water migration from the wash chamber into the fluid chamber.