Agricultural machines and tools
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Sickle

It is a simple harvesting tool. It is used for harvesting crops and cutting other vegetations . It is essentially consists of a metallic blade and a wooden handle. Blade is the main metallic part of the sickle. It is desirable to make the blade of carbon steel. It is made in a curved shape. The tooth of serrated sickle is made sharp for efficient working in the field. The handle of the sickle is made of well seasoned wood. The forged end of the blade for fixing the handle is called tang. The plain or serrated edge in the inner side of the blade is called cutting edge. Protective metallic bush fitted at the junction of the blade and the handle to keep the tang tight in the handle is called ferrule. Harvesting by sickle is very slow and labour consuming device.

Mower

Mower is a machine to cut herbage crops and leave them in swath. The conventional mower has the following main parts :

a) Frame to support moving parts
b) Power transmitting unit to receive and transmit motive force
c) Cutter bar to cut crops and separate it from uncut portion.
d) Wheels for transport and for operating the cutting mechanism
e) Auxiliary parts to lift and drop the cutter bar

Power transmitting unit

In bullock drawn mowers, the power transmitting unit consists of main axle, gears, crankshaft, crank wheel and pitman. The main axle receives power from one of the transporting wheels. A spur gear mounted on the main axle drives the spur pinion on one end of the countershaft in the gear box. The crank wheel and the pitman are fixed on the outer end of the crankshaft. The reciprocating (back and forth) motion is transmitted to the pitman, which in turns operates the knife in the cutter bar. The knife is connected to the pitman with a ball and socket joint. The knife makes about 1600 cutting strokes per minute. In order to engage or disengage the driving unit, generally a dog clutch is provided on the counter shaft so that the man can operate it by foot from the seat. The tractor drawn semi-mounted or mounted type mowers are operated by the P.T.O. shaft. In this case, the cutting mechanism is driven independently of the forward speed of the mower. A shaft is connected with the PTO shaft, which drives a V pulley with the help of a universal joint. The V pulley rotates another smaller pulley on the crank shaft of the machine and reciprocating motion is transmitted to the cutter bar. Other basic components of the machine are the same as that of bullock drawn mower with some variations in size and minor accessories

Combine harvester

Combine harvester is a machine designed for harvesting, threshing, cleaning and collecting the grain while it moves over the land. All the five operations are carried out in single operation of the harvester. The machine is versatile and with minor adjustments can handle a variety of crops. The size of the combine is indicated by the width of cut, it covers in the field.

Combine harvester in its primitive form was introduced in Germany and U.S.A. in late 19th century and became popular in next decades. In India, though a few tractor drawn combine harvesters manufactured by Minneapolis Moline U.S.A, and self-propelled Russian combine harvesters were available with some Govt. farms and landlords. However, between 1970-73 introduction of E512 GDR combine in Punjab, Haryana and M.P. was made in a big way. This was another revolution in the farm mechanization sector. Gradually indigenous production started with the manufacture of a Swaraj 8100 combine harvester in organized sector by M/s Punjab Tractors Ltd., which followed manufacturing of the machine in small sector in a small way. Surprisingly in 30 years of its production on commercial scale in India there are 60 more manufacturers with a production capacity of 5 to 150 combines per year. On an average about 800 combines are added every year on Indian farms. All these

Functions of combine harvester

1. Cutting the standing crops
2. Feeding the cut crops to threshing unit
3. Threshing the crops
4. Cleaning the grains from straw
5. Collecting the grains in a container

Bund Former

It is used for making bunds or ridges by collecting the soil (Fig.48). Bunds are required to hold water in the soil, thereby conserve moisture and prevent runoff. The size of the bund former is determined by measuring the maximum horizontal distance between the two rear ends of the forming boards. It is operated by both animal and tractor. Bund ormer consists of: (i) forming board, (ii) beam and (iii) handle. Forming board is made of mild steel of thickness 1.6 mm for light soil and 2 mm for medium and heavy soils

Ridger

It is an implement which cuts and turns the soil in two opposite directions simultaneously for forming ridges. It is also known as furrower. Ridger is used to form ridges, for sowing row crop seeds and plants in well tilted soil. The ridger is also used for forming field channels or furrowers, earthing up and similar other operations. Ridgers are also known as riding plough and double mould board plough. A ridger consists of beam, clevis, frog, handle, mould boards, braces, share, and sliding shoe. The ridger generally has V-shaped or wedge shaped share, fitted to the frog. The nose or the tip of the share penetrates into the soil and breaks the earth. The mould boards lift, invert and cast aside the soil, forming deep channels and ridges of the required size.


Bund Former

Mulcher
Leveller

In irrigated areas, land leveling is an essential operation for farming. Level fields receive uniform penetration of irrigation water with high efficiency. The possibility of water logging and soil erosion is reduced considerably. Land leveling is usually done in the slack season when the field is free from crops. Wooden logs or planks are the most common type of field levelers used by farmers. They are operated in ploughed land to collect loose soil from high spots and dump it into depressions. The other improved type of land leveler which is used on the large farms, is called the leveling karaha (scoop) or scraper.

Animal drawn soil scoop

Soil scoop is used in excavating ditches, cleaning drains and moving soil over short distances . The implement is pulled by a pair of bullocks. Two men are needed to operate it. One man controls the bullocks and the other man does the loading and unloading. It consists of: (i) blade, (ii) soil trough, (iii) Hitching loop and (iv) handle.

Blade: It is made of high carbon steel with carbon content varying from 0.5 to 0.6%. The angle of the cutting blade varies from 12 to 150 only. The blade is riveted or bolted to the soil trough.

Soil trough: It is made of mild steel sheet. It has two handles on the sides at the rear end.

Hitching loop: Two ends of the loop are fitted to the side of the soil trough. The loop is made of mild steel round.
Handle: Two handles, are usually made of timber or mild steel flat.