Impact sprinkler

An impact sprinkler (sometimes called an impulse sprinkler) is a type of irrigation sprinkler in which the sprinkler head, driven in a circular motion by the force of the outgoing water, pivots on a bearing on top of its threaded attachment nut. Invented in 1933 by Orton Englehart, it quickly found widespread use. Though it has in many situations been replaced by gear-driven "rotor heads", many varieties of impact sprinkler remain in use.