V. Make up your own sentences using the words from the vocabulary of the text.

VI. While translating indicate those sentences in which Complex Object is used:

1. This is quite the wrong view to take. 2. Assume the base of the column to be furnished with angles on the flanges. 3. Rollers not only cause a reaction to act at right angles to the supporting surface but also serve the purpose of allowing structures to expand and contract with changes in temperature. 4. Outside and in, the modern store must offer an invitation to the passerby to enter and to spend.

VII. Retell the information of the text “Power shovel”.


Compact Excavator

I. Read and translate the text using the words given below:

A compact or mini excavator is a tracked or wheeled vehicle with an approximate operating weight from 0.7 to 8.5 tons. It generally includes a standard backfill blade and features independent boom swing.

Hydraulic Excavators are somewhat different from other construction equipment in that all movement and functions of the machine are accomplished through the transfer of hydraulic fluid. The compact excavator's work group and blade are activated by hydraulic fluid acting upon hydraulic cylinders. The excavator's slew (rotation) and travel functions are also activated by hydraulic fluid powering hydraulic motors.

Most compact hydraulic excavators have three distinct assemblies: house, undercarriage and workgroup.

The house structure contains the operator's compartment, engine compartment, hydraulic pump and distribution components. The house structure is attached to the top of the undercarriage via a swing bearing. The house, along with the workgroup, is able to rotate or slew upon the undercarriage without limit due to a hydraulic distribution valve which supplies oil to the undercarriage components.

Slew Slewing refers to rotating the excavator's house assembly. Unlike a conventional backhoe, the operator can slew the entire house and workgroup upon the undercarriage for spoil placement.

The undercarriage consists of rubber or steel tracks, drive sprockets, rollers, idlers and associated components/structures. The undercarriage supports the house structure and the workgroup.

The workgroup of a compact hydraulic excavator consists of the boom, dipper or arm, and attachment (e.g. auger, bucket or breaker). It is connected to the front of the excavator's house structure via a swing frame that allows the workgroup to be hydraulically pivoted left or right to achieve offset digging for trenching parallel with the tracks.

The primary purpose of boom swing is for offset digging around obstacles or along foundations, walls or forms. A secondary use is cycling in areas too narrow for cab rotation. Independent boom swing is one of the major advantages of a compact excavator over other excavation equipment.

The backfill blade is used for grading, leveling, backfilling, trenching, and general dozer work. The blade can be used to increase dump height and digging depth depending on its position in relation to the excavator's workgroup, this makes it very versatile.

Fig. 7

In recent years, hydraulic excavator capabilities have expanded far beyond excavation tasks. With the advent of hydraulic powered attachments such as a tilt rotator, breaker, a grapple or an auger, the excavator is frequently used in many applications other than excavation and with the tilt rotator attachment, actually serves as an effective tool carrier (Fig. 7). Many excavators feature quick coupler (quick-attach) mounting systems for simplified attachment mounting, dramatically increasing the machine's utilization on the jobsite.

There are two distinct classes of compact excavators, conventional tail swing - units that have a rear counterweight that will extend beyond the tracks when the house rotates, and zero-tail swing - units with a house whose diameter stays within the width of the tracks through full rotation. Zero-tail swing units allow the operator to focus on digging and not watching where he or she is swinging.

II. Learn the vocabulary to the text:

Compact or mini excavator – мини-экскаватор

Boom swing – поворот стрелы крана

Workgroup – рабочая группа

Engine compartment – отсек двигателя, отделение силовой установки

Swing bearing – маятниковая опора, подшипник поворота, поворотный подшипник

Hydraulic distribution valve – гидро распределитель

Drivesprocket – ведущий зубчатый барабан, транспортирующий зубчатый барабан

Roller – ролик, валец, иголка (подшипника), вращающийся цилиндр

Idler – промежуточная шестерня, роликовая опора, вращающийся ролик

Tilt rotator – поворотно-наклонный механизм

III. Give the English equivalents to the following word combinations:

Строительное оборудование, выполнять функцию, гидравлический цилиндр, без ограничений, главное преимущество, увеличить глубину копания, часто использоваться во многих областях применения, полное вращение, вокруг фундамента, по отношению к, увеличивая использование аппарата.

IV. Give the Russian equivalents to the following word combinations:

Аpproximate operating weight, transfer of hydraulic fluid, travel function, the operator’s compartment, distribution component, the top of the undercarriage, the entire house, spoil placement, swing frame, to achieve offset digging, primary purpose, obstacle, cab rotation, to increase dump height, tool carrier, breaker, tail swing.

V. Answer the following questions using the information from the text:

1. What is a compact or mini excavator?

2. What does a mini excavator include?

3. Compact hydraulic excavators have three distinct assemblies, don’t they?

4. What does the house structure contain?

5. What can rotate or slew upon the undercarriage without limit?

6. What does the undercarriage comprise?

7. Do you know the main function of boom swing?

8. Is independent boom swing one of the advantages of a compact excavator?

9. Are there two or four distinct classes of compact excavators?