Spray nozzle assembly with expanded pressure responsive liquid flow rate control

An agricultural sprayer for spraying liquid agricultural chemicals in a controlled fashion based upon the pressure of the liquid agricultural chemical comprising:

• a tank of a selectively controllable pressurized supply of a liquid agricultural chemical;
• a tractor pullable elongated spray boom having a liquid supply conduit connected to said liquid chemical tank;
• a plurality of spray nozzle assemblies connected in laterally spaced relation along the length of said liquid supply conduit for receiving pressurized liquid agricultural chemical from said liquid agricultural chemical supply;
• said spray nozzle assemblies each having a nozzle body that defines a central liquid chemical flow passageway having an upstream end communicating with said pressurized liquid chemical supply and a downstream end wall having at least one discharge orifice;
• an annular orifice member disposed within said nozzle body having a central liquid flow passage in fluid communication with said nozzle body central liquid flow passageway;
• said nozzle body defining an expansion chamber closed by said downstream end wall into which liquid from said liquid flow passage of the orifice member is discharged for direction from said at least one discharge orifice;
• said orifice member having an upstream cylindrical section and a downstream cylindrical hub, said upstream cylindrical sections being larger in diameter than said cylindrical hub, said orifice member central liquid flow passage including a frustoconical passage section that communicates at least in part through both said upstream cylindrical section and downstream cylindrical hub and which has a frustoconical configuration inwardly tapered in a downstream direction at an angle of between 20 and 40 degrees that communicates with a discharge orifice of the orifice member at a terminal end of said hub for accelerating the flow of liquid chemical directed through said orifice member;
• said spray nozzle assemblies being supported in depending relation to said liquid supply conduit such that discharging liquid spray from said spray nozzles project downwardly onto a field along strips corresponding to the width of the spray boom as it is being pulled through the field by a tractor;
• said orifice member being made of a resilient and pressure responsive deformable material with said hub being freely expandable such that upon an increase in the pressure of the liquid agricultural chemical supply from 20 psi to 60 psi said liquid flow passage and discharge orifice thereof can be altered to predictably increase the flow rate of the liquid agricultural chemical through said orifice member and said at least one nozzle body discharge orifice up to at least 75 percent at liquid flow rates of 0.3 to 0.7 gal. per minute;
• and
• upon interruption of the supply of pressurized liquid to the orifice member the orifice member liquid flow passage and discharge orifice return to their original shape.