Mouldboard ploughs

The plough is amongst the earliest types of tillage implements invented to be drawn by animal power. Wooden sticks tied or spiked together, or tree forks were used first; later a metal point was added. It was not until the eighteenth century that the single-furrow plough, as we know it today, was evolved. Modern ploughs are lighter and stronger as a result of the use of improved materials. Also, they range from a single furrow to eight and ten furrows. The larger types are mostly found in wheat-growing areas.

Of late years various means have been evolved to couple the plough directly to the tractor, either by the use of mechanically or hydraulically controlled attachments.

To get useful and long life out of a plough, it is essential to keep it in good order. All nuts and bolts should be checked for tightness at fairly frequent intervals, because a loose or lost bolt places extra strain on other sections, causing them to get out of alignment or break.

The mouldboard plough is designed to cut and lift the soil, turn it over and bury the surface growth. (1) If it is to do this efficiently the mouldboard plough must have-

Sharp and correctly set shares, a level plough frame, a correctly adjusted hitch and ploughing speed best suited to the conditions.

The frame. The frame of a multiple-furrow plough should be level both vertically and laterally. If each foot is to plough at an equal depth and width, the frame members to which the feet are attached should run parallel to the line of draught and be an equal distance apart. (2) Twisted frame members cause an excessive strain on the plough, increasing the draught and the tractor fuel consumption.

The foot. The foot of a plough should be perfectly up-right and run true to the direction of travel.

The share. Plough shares should be kept sharp; blunt shares do poor work and require more power and fuel to draw the plough along. It is a good plan to have two sets of shares on hand so that when one is being sharpened the other does the work.

The coulter. The purpose of a coulter is to help penetration by cutting the hard soil surface, grass roots and other surface covering and to prevent the surface trash (3) packing around the plough foot. The coulter should not cut any deeper than 3 in. to 4 in. To lessen the draught and prevent excess wear, a rolling coulter should be kept oiled.

The mouldboard. The mouldboard's chief functions are to turn the soil over and bury the surface growth at the same time exposing the grass roots to the air so that they will die.

Mouldboards and shares should never be allowed to become rusty. Rusty mouldboards will not turn the soil cleanly, they tend to cake up (4) and increase the draught. It can be seen from this that rusty moulboards increase the tractor fuel consumption and the cost of operation.

NOTES:

(1) turn it over and bury the surface growth — переворачивать пласты

(2) be an equal distance apart — быть на равном расстоянии друг от друга

(3) surface trash — пожнивные остатки, трава и т.п. (эд.)

(4) tend to cake up — притупляются и с трудом проникают в почву

1. Study the following words:

Tillage, plough, mouldboard, hydraulically,hitch, attachments, depth and width, coulter, Twisted, draught, trash

2. Complete the sentences with appropriate words from the text:

a) The foot of a … be perfectly up-right and run true to the direction of travel.

b) Modern ploughs are … stronger as a result of the use of improved materials.

c) The purpose of a … help penetration by cutting the hard soil surface.

d). Rusty …will turn the soil cleanly, they tend to cake up.

3. Give your own definitions of the words:

Rusty, plough, root, attachments

4. Insert prepositions if necessary:

a) To lessen..draught and prevent excess wear, a rolling coulter should be kept oiled.

b) The frame …multiple-furrow plough should be level both vertically and laterally.

c) The purpose of a coulter is to help penetration …cut the hard soil surface.

d) The coulter should not cut any deeper than 3 …..4.

Text 4

MOWERS

MOWING MACHINES

Draft. The draft of mowers is a problem which varies with the grass that is being cut, the sharpness of the sickle, and the degree of lubrication.

In a series of tests, an 8-ft. mower in first-class condi­tion, cutting clover and timothy hay on level land, showed a draft of from 450 to 525 lbs., with an average of 487 lbs. Another 10-ft. mower, cutting alfalfa in good condi­tion and on level land, showed a draft of from 550 to 575 lbs., an average being of 566 lbs.

These figures are at the rate of travel of about 2.5 m.p.h. From them we find the average draft to be 58.7 lbs. per foot of sickle bar.

The sickle is known to be the part of a mower that does the work of cutting, and, therefore, requires attention to keep it in good shape and the knives sharp. In the first place, the knife should be absolutely straight. When found dull, the knife should be reground.

Grinding the knife sections is what should be very carefully done to keep the original angle of each section as nearly as possible. A special grinder for this purpose is a valuable device for doing this work well and doing it rapidly.

The effect of dull knives is plainly shown in the follow­ing data:

Condition of sickle: Draft in pounds:

Knives in good condition 455 to 478

Knives about 50 per cent dull 538 to 562
Knives very dull 560 to 622

This shows that a mower with dull knives may require about 75 per cent more power than when being in good condition.

Field tests reveal that the draft is slightly decreased as the travel increases. Thus faster travel accomplishes two things, viz. the mower does more work and does it with a minimum expense of power. The draft of a mower would increase if the machine were not lubricated well with a right kind of a lubricant.

THE MOWER

The first thing about a mower is to ensure that the cutterbar is aligned so that there is no side strain on the connecting rod.

To cut properly, the knife should travel backwards and forwards so that the sections stop and start in the centres of the fingers of guards. Check this by moving the con­necting rod, attached to the knife and crankpin, through its outward and inward strokes. (1) If the knife sections fail to travel (2) over the required area, the cause could be that the connecting rod is too long or too short, or that the cutterbar is incorrectly mounted.

Most mowers incorporate a screw adjustment that per­mits the cutterbar to be moved to or from the mower, but before making this adjustment, make quite sure that the connecting rod is the correct length. If a rod has been repaired by welding, its length may have been up­set. A wooden rod may have been repaired with the wrong length of wood. Or it may be that the original rod has been replaced by one that is identical in all but length.

No one needs to be told that the knife sections should be sharp, but many people do not realize that these sec­tions are only half the cutting mechanism. The other half is provided by the sides of the fingers or guards over which the sections travel. If these sides are blunt, the effect will be the same as trying to cut with scissors pos­sessing one sharp and one blunt edge. The cutting sides of the fingers are either integral parts of (3) the fingers or else formed by a ledger plate riveted on. If the ledger plate is serrated, it must be renewed when blunt, but if it is smooth it can be ground sharp in the same way as fingers with integral cutting edges. A few years ago it was usually necessary to remove the fingers before they could be sharpened, but the advent of the portable disc grinder has made it possible for the fingers to be ground in place. One of the snags of removing the fingers is the difficulty of getting them lined up (4) correctly when refitting them and, for this reason alone, the use of the portable grinder is to be preferred.

NOTES:

(1)through its outward and inward strokes — вперед и назад на про­тяжении всего его хода

(2)fail to travel—не двигаются

(3)are integral parts of — составляют единое целое с

(4)getting them lined up — выравнивание их

1. Study the following words:

Draft, mowers, lubrication, timothy, average, sickle, requires, sharp, absolutely straight, grinding, grinder, device, reveal, expense, lubricant

2. Complete the sentences with appropriate words from the text:

a) From them we … the average draft to be 58.7 lbs. per foot of sickle bar.

b) The draft of mowers is a problem which … with the grass that is being cut, the sharpness of the sickle, and the degree of lubrication.

c) A special grinder for this purpose is a valuable device for … this work well and doing it rapidly.

d) Grinding the knife sections is what should be very … done to keep the original angle of each section as nearly as possible.

e) When … dull, the knife should be reground.

3. Give your own definitions of the words:

mowers, lubrication, lubricant, device, expense

4. Insert prepositions if necessary:

a)Grinding the knife sections is what should be very carefully done to keep the original angle … each section as nearly as possible.

b) Another 10-ft. mower, cutting alfalfa … good condi­tion and on level land, showed a draft of from 550 to 575 lbs., an average being of 566 lbs.

c) The draft … mowers is a problem which varies with the grass that is being cut, the sharpness of the sickle, and the degree of lubrication.

d) The draft of a mower would increase if the machine were not lubricated well with a right kind … a lubricant.

e) These figures are at the rate … travel of about 2.5 m.p.h.

Text 5

BALERS