Agricultural spray nozzle with fluid operated orifice cleaning member

In an agricultural spray device having an upper pressure chamber and a lower pressure chamber, said chambers being divided by a diaphragm, said lower pressure chamber including a nozzle having an outlet orifice;

• a source of spray material;
• a first conduit means connecting said source with said chambers;
• valve means in said first conduit means for controlling the flow of material to either the upper or the lower chamber;
• a second conduit means connecting said upper chamber with said source for allowing material to flow out of said upper chamber to said source when said valve means is directing spray material to said lower chamber;
• and a punch affixed to said diaphragm, said punch having a diameter slightly smaller than said orifice and being movable in and out of said orifice so as to punch out any dirt or foreign material tending to clog said orifice, said punch also minimizing dripping when in said orifice said punch being movable into the orifice when said valve means allows material to flow to said upper chamber, said punch being movable out of said orifice when said valve means allows flow of material to said lower chamber;
• the improvement comprising:
• a third conduit means connecting said lower chamber with said source of spray material for allowing said spray material to flow out of said lower chamber to said source of spray material when said valve means is directing spray material to the upper chamber.