IL42301A - Sprinkler systems - Google Patents

Claims (10)

1. A system of pressure actuated intermittent discharge sprinkler units connected to a common water source each sprinkler unit comprising an accumulator adapted for connection to said water source for accumulating water under increasing pressure, and a pressure actuated water delivery head including a normally closed valve means, aaid head connected to said accu- mulator and said valve means being responsive to an increasing water pressure therein to intermittently discharge water to relieve the pressure in said accumulator and resume its normally closed condition, characterized in that a self— djusting flow control valve connects said accumulator of at least one of said sprinkler units to said sources of water such that periodic buildup and relief of pressure in said accumulator is not communicated to said source and thus does not adversely influence operation of the remaining sprinkler units connected to said source.

2. A system according to claim , in which each sprinkler unit comprises: an upstanding pipe member having a throat opening at an upper end and connected at lower end to said accumulator, 42301/3 a nozzle assembly slidably mounted on said pipe member for reciprocation between retracted and extended positions and having a nozzle for communicating vith said throat opening, said valve means carried by said nozzle assembly and movable therewith to the retracted position to close said throat opening of said pipe member and movable to the extended position communicating said nozzle and said throat opening, bias means urging said nozzle assembly and valve means to said retracted position such that the intermittent opening is accompanied by upward movement of said nozzle assembly to said extended position until the pressure of water in said accumulator is relieved by discharge through said nozzle.

3. A system according to claim 1 or 2 characterized in that each sprinkler unit head further comprises a rotation indexer including ratchet means carried by said nozzle assembly and said pipe member* said indexer translating each vertical cycle of assembly reciprocation into an increment of rotation thereof.

4. A pressure actuated periodic discharge sprinkler for subgrade installation according to any of claims 1 to 3 comprising: a pipe member for vertical disposition below a grade level and having a throat opening at an upper end thereof, a n annular guard skirt fixedly mounted vith an co-axially surrounding said pipe member adjacent said throat opening and having an upper rim for disposition substantially at grade level, a nozzle assembly slidably rotatably mounted on said pipe member for vertical reciprocation between retracted and extended positions and having a nozzle for communication with said pipe throat opening, said nozzle assembly including a horizontally mounted generally circular guard plate overlying said nozzle and disposed to assume a substantially flush relation with said guard skirt upper rim when said assembly is in its retracted position, valve means carried by said nozzle assembly and movable therewith downwardly to a retracted position closing said throat opening of said pipe member and movable upwardly to the extended position communicating said nozzle and throat opening, and spring bias means urging said nozzle assembly and valve means to said retracted position such that water under pressure in said pipe member overcomes the force of the bias means, forcing said valve means and assembly tft said extended position with said guard plate and nozzle rising above the rim of said skirt for nozzle clearance and water discharge until pressure is relieved.

5. A sprinkler according to claim 4, wherein said nozzle of said assembly is a primary nozzle having a relative large discharge passage and further comprising a secondary nozzle underlying said primary nozzle and having a relatively smaller discharge passage extending generally parallel to said primary nozzle passage, said secondary nozzle passage being disposed on said nozzle assembly such that a jet of water discharge therefrom during downward movement of said assembly toward its retracted position is intercepted by an upper edge of said guard skirt rim causing radially outward spray deflection of the secondary nozzle discharge jet and partially evacuating accumulated water in an upper cavity region of said guard member by a venturi action.

6. A sprinkler according to claim 4 or 5 wherein said guard skirt member is in the shape of an inverted truncated cone with the truncated end circumferentially secured to said pipe member at a location spaced below said throat opening and upwardly extending therefrom to define said rim.

7. An invention as defined in claim 4 vherein said pipe member is connected to a source of pressurized liquid, and including an accumulator and a conduit communicating the accumulator with said pipe member.

8. A sprinkler according to claim 7 including flow control means between said source and the conduit.

9. A sprinkler according to claim 8 wherein said flow control means comprises a self- adjusting valve having an opening therethrough, the effective size of the opening varying in general inverse relation to the difference of liquid pressure across the opening.

10. A sprinkler according to any of claims 7 to 9 wherein said accumulator includes upper and lower variable volume chambers separated by fluid impermeable means movable to change the volumes of the chambers, the upper chamber being charged with a pressurized gas and the lover chamber being connected to said conduit. - 27 42301/3 A system of pressure actuated intermittent discharge sprinkler units, substantially as hereinbefore described with reference to the accompanying drawings . For the Applicants DRf Yitzhak Hess