US Patent 8991724 Wobbling sprinkler with viscous brake

A sprinkler head includes a nozzle fixed within the sprinkler body, and a wobbler cage including a water deflector plate downstream of the nozzle mounted for rotating and wobbling motion relative to the sprinkler body. In certain embodiments, a viscous brake is fixed within the sprinkler body and includes a shaft rotatable about the longitudinal axis passing through the nozzle. The shaft is eccentrically coupled to the water deflector plate for slowing the rotating and wobbling motion of the wobbler cage and the water deflector plate.