Applicator for granular material

An applicator to be used on a vehicle for metering and discharging granular agricultural material, comprising:

• a hopper for holding the granular material, said hopper having a base containing a plurality of orifices therein whereby the granular material may fall through each of said orifices by the action of gravity, said plurality of orifices being disposed in a line;
• a rotatable shaft positioned below said orifices parallel to the line of said orifices in the vertical plane defined by said orifices;
• a plurality of metering wheels mounted on said shaft for rotation with said shaft in planes perpendicular to the axis of rotation of said shaft, each said wheel being vertically aligned with one of said orifices with the center of said wheel coinciding with the axis of rotation of said shaft whereby the uppermost point on the periphery of each said wheel is vertically aligned with one of said orifices;
• the uppermost point on the periphery of each said wheel forming a predetermined clearance with its orifice so that, given the dimensions and surface roughness of said wheels, the size of each said orifice, and the characteristics of the granular material, the granular material is discharged from between said hopper base and the periphery of each said wheel only when each said wheel is rotating and the rate of discharge depends only on the speed of rotation of said shaft and said wheels whereby the output of granular material is a linear function of the speed of rotation of said shaft and said wheels;
• a downwardly disposed collector tube positioned below each said wheel for receiving the granular material discharged from between said hopper base and said wheel and for conducting the granular material to a spreader means, each said collector tube having a funnel forming the top end of said tube into which the granular material spills and a discharge end;
• a motor for rotating said shaft and said wheels;
• means for setting the speed of said motor and thereby the speed of rotation of said shaft and said wheels;
• electric control means for automatically regulating said motor to maintain said shaft and said wheels at the set speed, said control means including means for constantly monitoring the speed of said motor and adjustment means for varying the electric input to said motor in accordance with the signals received from said monitoring means;
• and,
• means for forward and rearward positioning of said discharge ends of said collector tubes, said collector tube positioning means comprising a horizontally disposed cross bar connected to said collector tubes adjacent said discharge ends and means cooperating with said cross bar for pivoting said cross bar and thereby said discharge ends of said collector tubes with respect to said hopper.