Patent ID: 8800887

Claim:
A system for spraying liquid for agricultural purposes comprising: at least one liquid supply reservoir having an outlet conduit; a main supply conduit having a known internal volume; a plurality of laterally spaced nozzle sets; a plurality of supply branch conduits connected in parallel to each other to the main supply conduit and respectively connected to said plurality of laterally spaced nozzle sets, with each of said supply conduit branches having a known internal volume; a plurality of on/off valves respectively incorporated in said plurality of supply conduit branches; a primary pump coupled for receiving liquid from said outlet conduit of said liquid supply reservoir and for delivering fluid to said main supply conduit; a controller connected for controlling said primary pump for causing said primary pump to deliver liquid at a preselected volume flow rate set by an operator and with the controller further being connected for respectively controlling said plurality of on/off valves so as to close each on/off valve in response to an elapse of time equal to that calculated for the primary pump, when operating at said preselected volume flow rate, to fill the known internal volume of the supply conduit branch in which the on/off valve is incorporated, and with at least one of said supply conduit branches having an internal volume greater than at least another one of said supply conduit branches, whereby the controller will act to close the on/off valve associated with the at least one supply conduit branch prior to closing the on/off valve associated with the at least another one of the supply conduit branches, and the controller further being operable for terminating operation of said pump in response to the pump operating for an elapsed time equal to the time calculated for the pump to fill the combined known volumes of the main supply conduit and the plurality of conduit branches; and an operator control unit being coupled to said controller for setting said preselected volume flow rate and for providing information including the known internal volumes respectively of said main supply conduit and each of said plurality of branch conduits.