Spraying and irrigation equipment

Claim 1

A self-lifting spray head unit for sprinkling, irrigation and the like, which comprises, in combinaTion, an upstanding outer tube member connectable directly to a pressured source of liquid supply and having an inwardly directed annular stop and guide element at its upper end, an inner tube housed and freely slidable within said outer tube and annularly spaced therefrom by said stop and guide element and by an outwardly projecting guide flange carried at the lower end of said inner tube, said inner tube also carrying a spray nozzle at its upper end and an external annular compressible sealing gasket intermediate its ends and freely movable in the annular space between said tubes, the arrangement being such that flow of liquid from a connected pressure source first lifts the inner tube to elevated position and then compresses the gasket carried by the inner tube against the stop and guide element to seal the annular space, thereby directing total flow of said liquid through the spray nozzle, said nozzle made up essentially of an opposed pair of stiff but resilient plates with their peripheral edges normally in contact but adapted to separate slightly under high liquid pressure to provide a very thin annular flow outlet for said liquid, said plates being shaped to provide a wide angle, not less than 20* for the liquid towards the outlet to cause highly turbulent flow and thereby cause the liquid to break up into a fine misty spray, wherein said two plates are adjustably secured together so that the width of the annular outlet can be adjusted.