1.1. Workpiece

The main workpiece of a bulldozer is the blade. Depending on the type of activity the blades of different design are applied. The blade of box-shaped welded structure is the most widespread one.

*It is expedient when mining loose and friable grounds to fix lean-to-extenders to the blade. *They enable to boost the output of the bull­dozer by 40 - 50 %. If the blade displacing on average 1.5 - 2 m³ of soil is equipped with lean-to-extenders, its volume can be considerably in­creased up to 2.2 - 3 m³. Depending on the kind of the developed soil lean-to-extenders are installed either in parallel to the direction of jaws (dogs) of the blade or in the bevel way up to 60°. The blades of the bent shape with outstanding forward lateral parts (spherical) have appeared. They act as lean-to-extenders and have strength permitting to apply them on rocky soils.

*To operate on solid grounds the blade is equipped with change­able teeth, which are installed so, that they can break soil during the op­eration and reverse running of a bulldozer.

Geometry of the blade cutting part and the blade as a whole influ­ences the energy output of process, forming a prism of drawing and the earth moving.

Geometrical parameters (fig. 1.2) describing a blade are: the height of the blade H, the height of the blade with the visor H_v; the an­gle of leaning E₀; the radius of curvature of the blade R; the angle be­tween the horizontal and the tangent to the upper edge of the blade Bo, the height of the straight segment of the blade a, the angle of incidence of the visor Bv.

*During activity, the blade executes different operations; therefore, its structure profile is selected so that each parameter would allow to execute different parts of operation most rationally.

The most rational structure profile of the blade is that when the prism of drawing is formed so, that the layer of sheared off soil during operation on undistorted soil goes on the surface of the blade and falls in the direction of the bulldozer movement. In this case, the least activity for friction in soil that forms a prism of drawing is spent.

If the structure profile picked up abnormally, the sheared off soil during forming a prism will move upward not on the surface of the blade, but this soil will swell out the bulk of the soil that forms the prism. It results in large soil by soil friction losses. These losses increase when activity is carried out on the previously loosened soils.

Fig. 2. Geometry of a blade

Score: 10

Ex.6. Find in the text English equivalents to the following Ukrainian words and word-combinations:

коробчаста зварювальна структура, установити відвисні роз­ширю­вачі, під кутом, увігнута форма, бокові частини, нависні зубці, ріжуча частина леза, козирок, кут нахилу, кут падіння, контур структури леза, намощувати купу, збиток від тертя.

Score: 5

Ex.7. Arrange the words in pairs of synonyms:

activity, to execute, friable ground, soil ground, loose soil, work, to implement, hard soil, to boost, to use, to increase, to apply.

Score: 6

Ex.8. Form 7 sentences combining suitable parts of the table:

	The blade of box-shaped welded structure	is equipped with	the output of a bulldozer.
	Lean-to-extenders	is	changeable teeth to operate on solid grounds.
	The main work­piece of a bulldozer	can break	the most widespread one.
	The blade	forms	the blade.
	Changeable teeth	enable to boost	a prism of drawing.
	The structure profile of the blade	is	soil during the operation and reverse running of a bulldozer.
	The soil friction	allows to execute	different parts of operation most rationally.

Score: 7

Ex.9. Fill in the gaps with the words and word-combinations given below and translate the sentences.

1. The main workpiece of a bulldozer is the _________ .

2. Depending on the type of activity the blades of different ________ are applied.

3. It is expedient when mining ________ and ________ grounds to fix _________ to the blade.

4. Lean-to-extenders are installed either in parallel to the direction of _____ of the blade or in the _____ way up to 60°.

5. The blades of the bent shape with outstanding forward lateral parts have strength permitting to apply them on ______ soil.

6. To operate on ________ grounds the blade is equipped with _____ .

7. Geometry of the blade forms a _______ and the ________ .

8. The most rational structure profile of the blade is that when the layer of ______ soil during operation on ______ soil falls in the direction of the bulldozer movement.

9. If the structure _____ picked up abnormally it results in large soil by soil _______ .

10. These losses increase when activity is carried out on the previously _______ soils.

profile, rocky, earth moving, loosened, changeable teeth, undistorted, prism of drawing, friable, jaws, design, learn-to-extenders, blade, bevel, loose, solid, sheared off, friction losses.

Score: 10

Ex.10. Read the following and decide whether the statements are true or false. Correct them if necessary.

1. The main workpiece of a blade is the bulldozer.

2. Lean-to-extenders unable to boost the output of the bulldozer by 40-50%.

3. Lean-to-extenders are installed according to the kind of the developed soil.

4. The blades of the bent shape have strength permitting to apply them on loose soils.

5. Changeable teeth can reverse running of a bulldozer.

6. The most rational structure profile of the blade is that when the layer of sheared off soil moves upward not on the surface of the blade.

7. The most rational structure profile of the blade is that when the least activity for friction in soil is spent.

8. If the structure profile picked up abnormally the sheared off soil will swell out the bulk of the soil that forms the prism.

Score: 8

Ex.11.Match each word on the left with the correct definition on the right.

1.	friable	a)	firm, strong, compact, or substantial.
2.	to boost	b)	to cut with shears or a sharp instrument.
3.	jaws	c)	crumbly.
4.	rocky	d)	unchangeable, undeformed.
5.	solid	e)	to increase or raise.
6.	to execute	f)	hinged or sliding components of a machine or tool designed to grip an object.
7.	to shear off	g)	to carry out, complete, perform, do.
8.	undistorted	h)	consisting of or abounding in rocks.

Score: 8

Ex.12.

a) Find the equivalents to the following terms and word-combinations:

	friable ground		виконувати роботу
	to boost the output		недеформована земля
	jaws		зрізати
	rocky soil		нещільна земля
	solid ground		підвищувати видобуток
	to execute operation		кам’янистий грунт
	to shear off		затискні прилади
	undistorted soil		твердий грунт

b) Use them in sentences of your own.

Score: 8

Ex.13. Find in the text 4 sentences marked with *. State the function of the infinitive in the sentences. Translate them in writing.

Notes: Інфінітив у функції підмета (часто із залежними словами) здебільшого ставиться після присудка. В цьому випадку на початку речення перед присудком вживається ввідне -it-, що є формальним підметом:

It is not easy to write a poem.

Не легко писати вірша.

Інфінітив у функції обставини мети або наслідку може стояти (разом з означуваними словами) на початку речення (перед підметом), або в кінці речення:

To answer this question we must study the problem in detail.

Для того, щоб дати відповідь на це питання, ми повинні детально вивчити цю проблему.

Score: 4

Ex.14. Answer the following questions on the text:

1. What is the main workpiece of a bulldozer?

2. How many shapes of the blades can you find in the text? Name them.

3. What does the application of the blades of different design depend on?

4. What are the changeable teeth installed for?

5. How is the structure profile of the blade selected to execute different operations most rationally?

6. When is the least activity for friction in soil spent?

7. How is a prism of drawing formed?

Score: 7

Ex.15. Be ready to speak about the blade as the main workpiece of a bulldozer.

Score: 10

Total score: 100 points.

U N I T 4

Output

Ex.1. Learn to recognize the following international words:

transportation, to augment, resistance, opposite, phenomenon, process, cycle, uniform, section, to result, reserve, form, corridor, category, interval, total, stage, buffer.

Score: 2

Ex.2. Translate the following words into Ukrainian and state their part of speech:

to depend – dependable – dependence – independence;

distance – to distance – distanced;

necessary – necessarily – necessity – unnecessary;

to work – work – working – workful – workable – worker;

to resist – resistance – resistor;

opposite – to oppose – opposeless – opposition – oppositionist;

to execute – execution – executive – executor – executory;

use – to use – useful – useless – usable – usage – unused;

variable – to vary – variety – various;

reserve – to reserve – reserved – reservoir – reservation;

form – to form – formal – former – formless – formlessness – uniform;

to lose – losing – loser;

sum – to sum – sumless – summarize – summary;

to store – store – storage – stored

Score: 3

Ex.3. For the words given in a) find suitable prefixes in b).

a)

1. natural; 2. to organize; 3. possible; 4. to satisfy; 5. ordinary;

6. valuable; 7. large; 8. to cover; 9. to write; 10. to charge; 11.usual

b)

1. re; 2.in; 3.im; 4.un; 5.dis; 6. extra; 7. super; 8.en

Score: 3

Ex.4. Remember the meaning of these words and word-combinations:

mode of operation	–	режим роботи
terrain slope	–	похилість місцевості
thrust force	–	сила тяги
to augment	–	збільшувати(ся)
resistance to movement	–	опір руху
cut-in	–	початок роботи
depth of cutting	–	глибина копання
horizontal site	–	горизонтальна дільниця
gear	–	зубчата передача
soil shedding	–	випадіння землі
cylinder	–	валик
spacing interval	–	відстань
buffer	–	буфер

Score: 13

Ex.5. Read and translate the text.