Whirl spray nozzle

Claim 1

A spray nozzle for producing a hollow conical liquid spray pattern having a central air core comprising a body formed with a whirl chamber having a circular side wall and a bottom wall, said body having an inlet passage for directing liquid in a substantially tangential direction into said circular whirl chamber, means closing the top of said chamber and defining a circular spray discharge orifice disposed coaxially with the circular side wall of said whirl chamber, a post extending upwarding from said whirl chamber bottom wall, said post have a diameter of about one half the diameter of said whirl chamber and extending upwardly to an elevation about level with the upper perimeter of said inlet passage for guiding pressurized liquid introduced into said whirl chamber from said inlet passage in proper whirling direction about the circular side wall of said whirl chamber, and said post having an upper end formed with a recess which has an uninterrupted generally circular outermost perimeter, said recess extending an appreciable depth into the post but less than 1/2 the diameter of said post and being in axial alignment with said discharge orifice and said annular side wall for recieving the lowermost end of the air core of the whirling liquid within said chamber for retaining the proper axial position of the air core and whirling liquid without substantial diffusion of the hollow cone spray pattern and for preventing damage to said body from said air core and whirling liquid.