Seed metering mechanism

• The mechanism of a seed drill or fertilizer distributor which delivers seeds or fertilizers from the hopper at selected rates is called seed metering mechanism.

Types of seed metering mechanism

a) Fluted feed type:

• It is a seed metering device with adjustable fluted roller to collect and deliver the seeds into the seed tube.
• consists of a fluted wheel, feed roller, feed cut-off and adjustable gate for different sizes of grains.
• Feed roller throws the grains out on the adjustable gate from where it falls into the seed tube.
• The fluted roller receives seeds into longitudinal grooves and pass on to the seed tube through the holes.
• By shifting the fluted wheel sideways, the length of the grooves exposed to the seed can be increased or decreased.

b) Internal double run type:

• It is a seed metering device in which the feed wheel is provided with fine and coarse ribbed flanges.
• It consists of discs, mounted on a spindle and housed in a casing fitted below the seed box.
• one face has a larger opening for larger seeds and the other face has smaller opening for smaller seeds.
• A gate is provided in the bottom-of the box to cover the opening not in use.
• The rate of seeding is varied by adjusting the speed of the spindle which carries the discs.

c) Cup feed mechanism:

• It is a mechanism consisting of cups or spoons on the periphery of a vertical rotating disc which picks up the seeds from the hopper and delivers them into the seed tubes.
• Consists of seed hopper; upper one called grain box and lower one called feed box.
• The seed delivery mechanism consists of a spindle. The spindle with its frame and attachment is called seed barrel.
• When the spindle rotates, one disc with its set of cups rotates and picks up few seeds and drops them into small hoppers.

d) Cell feed mechanism:

• It is a mechanism in which seeds are collected and delivered by a series of equally spaced cells on the periphery of a circular plate or wheel.

e) Brush feed mechanism:

• It is a mechanism in which a rotating brush regulates the flow of seed from the hopper.

f) Auger feed mechanism:

• It is a distributing mechanism, consisting of an auger which causes a substance to flow evenly in the field, through an aperture at the base or on the side of the hopper.

g) Picker wheel mechanism:

• It is a mechanism in which a vertical plate is provided with radially projected arms, which drop the large seeds like potato in furrows with the help of suitable jaws.

h) Star wheel mechanism:

• It is a feed mechanism which consists of a toothed wheel, rotating in a horizontal plane and conveying the fertilizer through a feed gate below the Star wheel.