Patent ID: 6854148

Claim:
In a trackless automatic pool cleaner of the type motivated by the flow of water therethrough to move along a pool surface to be cleaned, the pool cleaner having four wheels each in trackless direct contact with the pool surface, the improvement comprising: a body having a front side, a rear side and opposite sides, the wheels being rotatably mounted with respect to the body and including first and second sets of two wheels each, each set including one of the wheels on each side of the body; a turbine housing secured to the body and having a water-flow chamber formed by a chamber wall, the chamber having inlet and outlet ports; a turbine rotor rotatably mounted in the chamber; turbine vanes having proximal edges connected to the rotor and distal edges freely movable at all rotational positions thereabout between extended positions adjacent to the wall and retracted positions spaced farther from the wall and closer to the rotor, thereby to allow passage of debris pieces of substantial size through the turbine; and a drive train from the rotor to the first set of wheels and to the second set of wheels for trackless driving of all four wheels; whereby all four wheels are driven.