Farm Power And Machinery (1+1)

Adjustment of mould board plough

• For proper penetration and efficient work by the mould board plough, some clearance is provided in the plough.
• This clearance is called suction of the plough.
Suction in mould board plough is of two types

(i) Vertical suction and
(ii) Horizontal suction.

Vertical suction (Vertical clearance)

• It is the maximum clearance under the land side and the horizontal surface when the plough is resting on a horizontal surface in the working position.
  
• It is the vertical distance from the ground, measured at the joining point of share and land side.
  
• It helps the plough to penetrate into the soil to a proper depth.
  
• This clearance varies according to the size of the plough.
  
• The vertical clearance is shown in Fig.12.8.


Fig. 12.8 Vertical suction of mould board

Horizontal suction (Horizontal clearance)

• It is the maximum clearance between the land side and a horizontal plant touching point of share at its gunnel side and heal of land side.
  
• This suction helps the plough to cut the proper width of furrow slice.
  
• This clearance varies according to the size of the plough.
  
• It is also known as side clearance and is shown in Fig.12.9.


Fig. 12.9 Horizontal suction of mould board

Throat clearance

• It is the perpendicular distance between point of share and lower position of the beam of the plough. The throat clearance of mould board plough is shown in Fig. 12.10.


Fig. 12.10 Throat clearance of plough

Vertical clevis

• It is a vertical plate with a number of holes at the end of the beam to control the depth of operation and to adjust the line of pull. The vertical clevis and line of pull is shown in Fig.12.11.


Fig. 12.11. Vertical Clevis and line of pull

Horizontal clevis
It is a device to make lateral adjustment of the plough relative to the line of pull.
Plough size
The perpendicular distance from wing of the share to the line jointing the point of the share and heel of land side is called size of plough. The size of the mould board plough is expressed by width of cut of the soil.