The present invention relates to irrigation equipment, and more particularly, to sprinklers used to irrigate lawns, playing fields, golf courses and the like.
Sprinklers have long been used to water turf and other vegetation. Many designs have been developed with the goal of uniformly distributing a desired precipitation rate over a given area. One of the most common type of sprinklers is the pop-up type that is normally mounted in a subsurface location so that the top of the sprinkler is substantially at ground level. When water pressure is applied a riser with a nozzle at its upper end extends and delivers a spray of water over the adjacent area. When the water pressure is terminated, a spring retracts the riser so that the upper end of the nozzle is flush with the head of the sprinkler. This removes the sprinkler as an obstacle to play occurring on the turf and allows the turf to be mowed.
Pop-up sprinklers having internal water turbines for rotating their nozzles have been developed and widely commercialized. Furthermore, pop-up sprinklers with diaphragm type valves incorporated into the same are widely utilized. A common type of pop-up sprinkler has an internal diaphragm valve which is opened and closed by a solenoid or a hydraulically operated pilot valve. The solenoid and/or. pilot valve components of such valves frequently fail during their normal life cycle. It is then necessary to shut off the water supply and dig up the sprinkler so that the defective components can be repaired, or the sprinkler replaced in its entirety. This is a tedious and time consuming process.
U.S. Pat. No. 5,871,156 of Kenneth L. Lawson granted Feb. 16, 1999, discloses an impact drive sprinkler mounted on a reciprocable riser inside a hollow body having an inlet valve at its lower end. A regulator module is connected to the valve and is suspended beneath a non-circular ground support flange. The non-circular shape of the ground support flange is disfavored by irrigation system installers because a circular turf cut-out made with a conventional tool does not accommodate this sprinkler. In addition, the regulator module must be removed via excavating below the ground support flange, or removing the sprinkler from the ground entirely.
It would be desirable to provide a sub-surface sprinkler with a built-in valve and a valve actuating components that could be more readily serviced without having to dig up the sprinkler.