Sprinkler having a flow rate compensating slow speed rotary distributor

A rotary sprinkler head comprising a sprinkler body having an outlet and means devoid of any operative dynamic seals for communicating a source of water under pressure with said outlet, said outlet being defined by surface means for directing water under pressure communicated therewith into an atmospheric condition in a primary stream having a generally vertically extending axis, a rotary distributor mounted for rotational movement about a rotational axis with respect to said sprinkler body in engaging relation with respect to the primary stream directed from said outlet, said rotary distributor having surface means for engaging the primary stream (1) to establish a reactionary force component acting on said distributor in a direction tangential to the rotational axis thereof so as to effect rotational movement thereof about said axis of rotation and (2) to direct the primary stream engaged thereby in the form of pattern forming stream means including at least one stream moving away from said distributor in a direction having a substantial component extending radially outwardly from the generally vertical axis of said primary stream, speed reducing means operatively associated with said distributor for reducing the rotational speed of the distributor resulting from said reactionary force component from a relatively high whirling speed which would occur without said speed reducing means to a relatively slow speed so related to the distributor surface means forming the pattern forming stream means as to permit (1) said one stream to leave said distributor surface means with sufficient stream integrity to flow outwardly a distance substantially as great as the same said one stream would flow if the distributor were held stationary and (2) all of the pattern forming stream means including said one stream to be distributed within a generally circular pattern with a desired droplet size and with a desired water distribution within said generally circular pattern being defined by the maximum extent of flow of said one stream, the improvement which comprises

• the surface means defining said outlet being provided by a selected one of a series of different nozzles defining different size outlets within a relatively large range of different sizes,
• said distributor surface means being operable to establish a reactionary force component acting on said distributor in a direction tangential to the rotational axis thereof so as to effect rotational movement at a predetermined speed when the selected nozzle defines an outlet of minimum size within said range and the water under pressure communicated with said outlet is at a predetermined operative value,
• said distributor surface means being operable to limit the amount of increase in the established reactionary force component acting on said distributor in a direction tangential to the rotational axis thereof when the selected nozzle defines an outlet of maximum size within said range and the water under pressure communicated with said outlet is at said predetermined operative value so as to limit the increase in the effected rotational speed with respect to said predetermined speed to one wherein said one stream flows outwardly a distance substantially as great as the same said one stream would flow if the distributor were held stationary.