Step-by-step rotary sprinkler head with quick-change and color-coded nozzle insert

Claim 1

A step-by-step rotary sprinkler head comprising a hollow sprinkler body having an inlet and an outlet, means for mounting said hollow body in communication with a source of water under pressure for controlled step-by-step rotary movement about an axis extending generally vertically in operation, an impulse arm mounted on said hollow body for oscillatory movement toward and away from a limiting position with respect to said hollow body, said outlet extending upwardly and outwardly with respect to the axis of rotation of said hollow body and having a nozzle insert mounted therein for directing flow of water under pressure communicated with said inlet outwardly thereof, and means including a reactant element on said arm engageable with a stream issuing from said nozzle insert for effecting successive oscillatory movements of said arm and for effecting successive step-by-step incremental rotational movements of said hollow body about its axis of rotation during each oscillatory movement of said arm, said outlet being provided by an annular wall having an outer end surface, said annular wall having a cylindrical surface formed on the interior thereof adjacent said outer end surface and threads formed on the interior thereof inwardly of said cylindrical surface, said nozzle insert having an inlet end and a discharge end and being formed with a discharge orifice therein adjacent said discharge end communicating with said inlet end by a passage which converges in a direction toward said orifice, said nozzle insert having straight threads formed on the exterior periphery thereof adjacent the inlet end thereof for loosely cooperatively engaging said threads within said annular wall, said nozzle insert having a first annular groove formed in the exterior periphery thereof adjacent the inner end of said threads, an O-ring of resilient material disposed within said annular groove having an exterior diameter greater than the exterior diameter of the adjacent threads on said nozzle insert, said cylindrical surface having a diameter greater than the trough diameter of the threads extending inwardly thereof but less than the exterior diameter of said O-ring so as to engage and compress said O-ring radially inwardly in response to the digital turning of said nozzle insert with said threads in loose cooperative engagement so that the compressive engagement of said O-ring with said cylindrical surface and within said groove provides a water-tight seal between the exterior periphery of said nozzle insert and the interior periphery of said annular wall and a frictional force sufficient to resist turning movement of said nozzle insert in a direction to remove the same as a result of the vibrations to which the sprinkler body is subjected during normal operation of the sprinkler head, said nozzle insert having a second annular groove formed in the exposEd exterior periphery thereof, and a preformed band of resilient material having a coloring agent dispersed therein mounted within said annular groove by expanding the band over the nozzle insert and allowing it to contract within said groove, said coloring agent being of a predetermined color associated with the size of said orifice.