There are a number of metering and dispensing machines on the market for dispensing granular chemicals, seeds and fertilizers in agricultural environments. A problem with many machines is that the metering and dispensing rate for the granulated material cannot be kept constant when the metering apparatus is traversing sloped terrain. In other instances, many metering machines are not capable of maintaining constant dispensation rates per area with changing velocities of the metering and dispensing machine. A problem with other particulate metering and dispensing machines is that the machines cannot accommodate various sizes of particulate material. They either plug up or they cannot maintain consistent dispensing rates.
Many machines currently on the market for metering and dispensing particulate material use fluted rollers, choked augers, or individual fluted rollers, for metering and controlling the dispensing rate of the particulate material. These machines use fixed displacement metering cavities which limit the particle size that can be metered. Larger sizes cannot be handled without damage occurring to the machine. Another problem is that many machines on the market have high power requirements due to fixed displacement designs and thus are expensive to operate.
A number of patents have issued over the years for various designs of feeders and dispensers.
U.S. Pat. No. 206,047, Shrake, shows a feeder with a hopper that has a rotating cylindrical metering device at the bottom. The metered material drops into a second hopper which has a longitudinally scalloped cylinder which dispenses the material in metered amounts. The amount metered is controlled by the position of gate D.
U.S. Pat. No. 7,926, Winchell, illustrates a seeding machine which has a toothed cylinder which is located at the base of a hopper and meters seeds at an adjustable rate. The rate is adjusted by gate e.
U.S. Pat. No. 3,606,965, Cortelyou, discloses a dispenser for use with lawn combines, which dispenses seeds and fertilizers by means of rotating, compartmented, cylindrical drums. The amount of material that is to be dispensed by the device is controlled by the number of compartments on the cylindrical drum that is exposed to the reservoir of materials.
U.S. Pat. No. 4,408,704, Steilen, discloses an adjustable and flexible metering gate for a fluted feed cup assembly on a grain drill. The metering gate is fabricated from a flexible material, and the adjusting lever for the gate is located on the side of the cup opposite the portion of the fluted feed roll. The fluted feed roll is exposed to the grain so that the gate can flex and pass foreign objects without damage and then return to its original position. The feed cup is fabricated from plastic.
U.S. Pat. No. 4,522,340, Gandrud, discloses an applicator for precisely dispensing granular materials, such as herbicides, pesticides and the like. The applicator improves control while compensating for the speed and travel direction of the implement carrying the applicator. The applicator comprises a hopper with an arcuate hopper bottom extension and an internal feed rotor. The arcuate hopper bottom extension is inclined, and the openings in the end include straight lowermost sides oriented parallel to the rotational axis of the feed rotor to obtain better flow control in conjunction with a revolving transfer means located beneath and closely adjacent to the bottom end of the hopper. The revolving transfer assembly includes a plurality of rollers for individually receiving material from the openings in the hopper and distributing it for application. The feed rotor and transfer assembly are vertically and laterally offset and are interconnected for counter rotation in unison responsive to travel of the applicator such that the rate of material application is directly proportional to the speed of travel.
U.S. Pat. No. 4,705,220, Gandrud, et al., discloses an improved, more versatile applicator for precisely dispensing granular chemicals, fertilizers or seed. The applicator includes a hopper with a metering assembly mounted over a material discharge opening in an inclined wall of the closed, convergent bottom end of the hopper. The metering assembly, which is preferably removably secured to the hopper, includes a plurality of individual sets of metering wheels, receivers and gate plates for precise control and more tolerance to tilt. The metering assembly is also adapted to facilitate thorough clean-out of the hopper as well as removal and replacement of the metering wheels without emptying the hopper.