Patent ID: 8297533

Claim:
A sprinkler, comprising: a riser having an inlet end and an outlet end; a nozzle having a plurality of circumferentially spaced, radially extending stream forming channels; a drive assembly mounted in the riser having an output shaft rotatably supporting the nozzle at the outlet end of the riser; an impeller coupled to an input shaft of the drive assembly; a rotatable manually adjustable orifice plate adjustable by rotation, the adjustable orifice plate located adjacent the outlet end of the riser and having an aperture shaped to deliver water flowing through the riser into the stream forming channels in a manner that produces an adjustable arc of coverage for water distribution onto the landscape; a stationary orifice plate adjacent to the manually adjustable orifice plate and having at least one radially extending tab that locks into the riser; cape; a stationary orifice plate adjacent to the manually adjustable orifice plate and having at least one radially extending tab that locks into the riser; the adjustable orifice plate including at least one arc setting tab that engages with the riser to prevent rotation under normal operation, the at least one tab being deflected by an operator to disengage the tab from the riser to rotate the adjustable orifice plate to increase or decrease an arc of water distribution.