Components of Mould board plough
The share is one of the important part of the plough, which penetrates into the soil and makes a horizontal cut below the soil surface. It is a sharp, well polished and pointed component. The different parts of the share are shown in Fig. 12.2.
- Share point : It is the forward end of the cutting edge which actually penetrates into the soil .
- Cutting edge: It is the front edge of the share which makes horizontal cut in the soil.
- Wing of share: It is the outer end of the cutting edge of the share. It supports the plough bottom .
- Gunnel: It is the vertical face of the share which slides along the furrow wall. It takes the side thrust of the soil and supports the plough bottom against the furrow wall.
- Cleavage edge: It is the edge of the share which forms joint between mould board and share on the frog.
- Wing bearing: It is the level portion of the wing of the share, providing a bearing for the outer corner of the plough bottom.
Fig. 12.2 Different parts of the shareMaterial of share
- The shares are made of chilled cast iron or steel. The steel mainly contains about 0.70 to 0.80% carbon and about 0.50 to 0.80% manganese besides other minor elements.
Type of Share
There are four different types of shares used for the mould board plough such as Slip share, Slip nose share, Shin share and Bar point share and are shown in Fig.12.3.
Slip nose share
- It is one piece share with curved cutting edge, having no additional part. It is a common type of share, mostly used by the farmers. It is simple in design, but it has got the disadvantage that the entire share has to be replaced if it is worn out due to constant use.
- It is a share in which the point of share is provided by a small detachable piece.
- It has the advantage that share point can be replaced as and when required.
- If the point is worn out, it can be changed without replacing the entire share, effecting considerable economy.
Bar point share
- It is the share having a shin as an additional part. It is similar to the slip share with the difference that an extension is provided to it by the side of the mould board.
- It is the share in which the point of the share is provided by an adjustable and replaceable bar. This bar serves the purpose of point of the share and land side of the plough.
Fig. 12.3 Different types of shareMould board
- The mould board is that part of the plough which receives the furrow slice from the share. If lifts, turns and breaks the furrow slice. To suit different soil conditions and crop requirements, mould board has been designed in different shapes. There are four types of mould board used such as : General purpose, Stubble, Sod or Breaker and Slat.
General purpose It is a mould board having medium curvature lying between stubble and sod. The sloping of the surface is gradual. It turns the well defined furrow slice and pulverizes the soil thoroughly. It has a fairly long mould board with a gradual twist, the surface being slightly convex. The general purpose mould board is shown in Fig.12.4
Fig. 12.4 General purpose mould boardStubble type
- It is short but broader mould board with a relatively abrupt curvature which lifts breaks and turns the furrow slice used in stubble soils.
- Its curvature is not gradual but it is abrupt along the top edge.
- This causes the furrow slice to be thrown off quickly, pulverizing it much better than other types of mould board.
- This is best suited to work in stubble soil that is under cultivation for years together.
- Stubble soil is that soil in which stubble of the plants from the previous crop is still left on the land at the time of ploughing.
- This type of mould board is not suitable for lands full of grasses and is shown in Fig. 12.5.
Fig. 12.5 Stubble mould boardSod or Breaker type
- It is a long mould board with gentle curvature which lifts and inverts the unbroken furrow slice.
- It is used in tough soil of grasses. It turns over thickly covered vegetable of the soil.
- This is very useful where complete inversion of soil is required by the farmer.
- This type has been designed for used in sod soils.
- The sod or breaker type mould board is shown in Fig. 12.6.
Fig. 12.6 General purpose mould boardSlat type
- It is a mould board whose surface is made of slats placed along the length of the mould board, so that there are gaps between the slats.
- This type of mould board is often used, where the soil is sticky, because the solid mould board does not scour well in sticky soils and is shown in Fig.12.7.
Fig. 12.7 Slat mould board
- It is the flat plate which bears against and transmits lateral thrust of the plough bottom to the furrow wall.
- It helps to resist the side pressure exerted by the furrow slice on the mould board.
- It also helps in stabilizing the plough while it is in operation. Land side is fastened to the frog with the help of plough bolts.
- The rear bottom end of the land side is known as heel which rubs against the furrow sole.
- Frog is that part of the plough bottom to which the other components of the plough bottom are attached (Fig.6 ).
- It is an irregular piece of metal. It may be made of cast iron for cast iron ploughs or it may be welded steel for steel ploughs.
- It is an important extension of mould board which helps in turning a furrow slice.
Last modified: Tuesday, 26 June 2012, 1:35 PM