Liquid spreader control system

An automatic control system for use with a vehicular liquid sprayer of the type which pumps the liquid to be sprayed at a desired pressure to a plurality of nozzles which dispense the liquid at a predetermined desired density relative to the area being sprayed, said density being a function of the ground speed of the sprayer and a plurality of liquid spraying parameters including the rate of flow of liquid, the width covered by each nozzle, and the size of each nozzle, said control system comprising:

• means for sensing the pressure of the liquid supplied to said nozzles and developing a corresponding electrical liquid pressure signal;
• means for measuring the ground speed of said vehicular sprayer and developing a corresponding electrical ground speed signal;
• programming means coupled to said ground speed measuring means for selectively modifying said ground speed signal to obtain a modified ground speed signal having a characteristic which corresponds to the values of said rate of flow, said nozzle width, and said nozzle size required to obtain said desired density;
• means responsive to said liquid pressure signal and said modified ground speed signal for generating a corresponding valve control signal;
• and control valve means operatively coupled to said nozzles and responsive to said valve control signal for adjusting the rate of flow of said liquid to said nozzles to maintain the pressure of the liquid at the nozzles at a level which corresponds to said valve control signal, whereby the vehicular liquid sprayer is automatically adjusted to maintain the system pressure at the nozzles at the level which corresponds to the selected values of rate of flow, nozzle width, nozzle size, and variations in the ground speed of the sprayer and fluctuations in the pressure of the liquid supplied to the nozzles to thus spray the liquid at the desired density.

An automatic control system for use with a vehicular liquid sprayer of the type which pumps the liquid to be sprayed at a desired pressure to a plurality of nozzles which dispense the liquid at a predetermined desired density relative to the area being sprayed, said density being a function of the ground speed of the vehicular sprayer and a plurality of liquid spraying parameters including the rate of flow of liquid, the width covered by each nozzle, and the size of each nozzle, said control system comprising:

• means for sensing the pressure of the liquid supplied to said nozzles and developing a corresponding electrical liquid pressure signal;
• means for measuring the ground speed of said vehicular sprayer and developing a corresponding electrical ground speed signal;
• nozzle width attenuator means coupled to said ground speed sensing means for selectively modifying said ground speed signal to obtain a modified ground speed signal having a magnitude which corresponds to the width covered by each said nozzle required to obtain said density;
• rate of flow attenuator means coupled to said nozzle width attenuator means for further selectively modifying said ground speed signal to obtain an attenuated ground speed signal having a magnitude which also corresponds to the rate of flow of liquid required to obtain said density;
• nozzle size attenuator means coupled to said rate of flow attenuator means for further selectively modifying said ground speed signal to obtain an attenuated ground speed signal having a magnitude which also corresponds to the nozzle size required to obtain said density;
• means responsive to said liquid pressure signal and said attenuated ground speed signal for generating a corresponding valve control signal;
• and control valve means operatively coupled to said nozzles and responsive to said valve control signal for adjusting the rate of flow of said liquid to said nozzles to maintain the pressure of the liquid at the nozzles at a level which corresponds to said desired density, whereby the vehicular liquid sprayer is automatically adjusted to maintain the system pressure at the nozzles at the level which corresponds to the selected rate of flow, nozzle width, nozzle size, and variations in the ground speed of the sprayer and fluctuation in the pressure of the liquid supplied to the nozzles to thus spray the liquid at the desired density.

A vehicular liquid sprayer of the type which pumps the liquid to be sprayed at a desired pressure to a plurality of nozzles which dispense the liquid at a predetermined desired density relative to the area being sprayed, said density being a function of a plurality of liquid spraying parameters which may vary from one spraying application to another or from time to time during a given spraying application, said control system comprising:

• means for sensing the pressure of the liquid supplied to said nozzles and developing a corresponding first electrical signal;
• means for measuring the ground speed of the said vehicular sprayer and developing a corresponding second electrical signal;
• programming means responsive to one of said first and second electrical signals for selectively modifying said one electrical signal to obtain a modified electrical signal having a characteristic which corresponds to the values of at least two of said liquid spraying parameters required to obtain said desired density;
• means responsive to the other one of said first and second electrical signals and to said modified electrical signals for generating a corresponding valve control signal;
• and control valve means operatively coupled to said nozzles and responsive to said valve control signal for adjusting the rate of flow of said liquid to said nozzle to maintain the system pressure at the nozzle at the level which corresponds to the selected values of the liquid spraying parameters to thus spray the liquid at the desired density.