Nozzle assembly for low pressure impact sprinkler

In an impact sprinkler comprising a sprinkler body, means for connecting said sprinkler body to a source pipe in communicating relation to a source of water under pressure contained therein for controlled step-by-step rotational movement about a vertical axis, said sprinkler body having at least one outlet, a nozzle assembly in said outlet for directing water under pressure communicating with said sprinkler body in a stream extending radially outwardly and upwardly with respect to said vertical axis, an impact arm mounted on said sprinkler body for oscillatory movement to effect the step-by-step rotational movement of said body and a spoon on said arm for engaging the stream issuing from said nozzle assembly to effect the oscillatory movement of said impact arm, the improvement which comprises said nozzle assembly comprising

• a generally flat member of wear resistant thermoset elastomeric material having an aperture in the central portion thereof constituting the stream defining orifice of the nozzle and
• means for mounting said elastomeric member in the outlet of said sprinkler body including a rigid backing member having a central opening through which the stream defined by the nozzle orifice passes,
• said backing member having surface means surrounding said opening and facing in a direction opposed to the direction of stream movement operable to engage and support said elastomeric member in a deformed operative condition in which first portions of said flat member defining vertically diametrically opposed portions of the periphery of the aperture thereof are disposed in downstream spaced relation with respect to second portions thereof defining horizontally diametrically opposed portions of the periphery of the aperture thereof displaced 90.degree. from said first portions so that the stream as it issues from the aperture of the flat member in said deformed condition tends to remain flattened in the vertical direction of said first portions and to fan out in a desirable droplet size in the horizontal direction of said second portions.