Patent ID: 7216817

Claim:
A rotary sprinkler comprising: a housing having an inlet for receiving water flow from a water source; a nozzle in communication with the inlet for producing a water stream from the water flow; a shaft assembly rotatably supported by the housing and including a distribution outlet for directing and discharging the water stream from the sprinkler in a first distribution direction; a drive assembly for rotating the shaft assembly in response to receiving a portion of the water stream for a period of time to relocate the distribution outlet to discharge water from the distribution outlet in a second distribution direction, the drive assembly including an impact arm having an outer surface and a water-receiving surface defining an arm inlet, an arm outlet, a passageway between the arm inlet and the arm outlet, and a discharge portion for discharging water from the arm outlet, wherein the water stream imparts to the water-receiving surface a first force in a first direction to move the drive assembly away from the water stream and a second force to move the drive assembly toward the shaft assembly to relocate the distribution outlet, the water-receiving surface being configured so that during the period of time the second force is greater than the first force generally at least until relocating the distribution outlet.