Patent ID: 8110141

Claim:
A pump base for use in a molten metal pump, the pump base having (a) an inlet, (b) a pump chamber in communication with the inlet, (c) a discharge through which molten metal exits the pump chamber, and (d) a device comprising: a plurality of openings through which molten metal can pass, wherein each of the plurality of openings is partially defined by an inlet perimeter; a plurality of imperforate rotor blades for displacing molten metal, wherein each of the plurality of rotor blades has a leading face that includes a first portion that directs molten metal downward and a second portion beneath the first portion that directs molten metal outward, and a trailing face that includes a recess that increases the size of one of the openings to help permit molten metal to pass therethrough and into the pump chamber; wherein as the device is rotated, the openings, each inlet perimeter, and the rotor blades rotate.