Patent ID: 7780015

Claim:
Apparatus for moving material relative to a floor of a basin, comprising: at least one first blade having a first orientation; at least one second blade having the same orientation as the at least one first blade; at least one third blade having a second orientation; at least one fourth blade having the same orientation as the at least one third blade; the at least one first and second blades are located on a single axis; the at least one third blade and at least one fourth blade are located on the same axis as and apart from the at least one first and second blades; a reciprocating drive configured to simultaneously move each of the at least one first, second, third and fourth blades relative to the floor of the basin; and wherein the at least one first and second blades have a first orientation to move material relative to a floor of a basin in a first direction, wherein the at least one third and fourth blades have a second orientation to move material relative to a floor of a basin in a second direction, and wherein the first direction is different from the second direction.