XVI. Переведите текст с учетом выполненных заданий. Первый абзац переведите письменно.

 

1.When machining a piece of work on a lathe the former is usually mounted between the lathe centers. Having been mounted on the lathe the work is supported by the conical points of the live and dead centers. The work must therefore have centre holes drilled in each end. The size of the centre hole has to be proportioned to the weight of the work and size of cut to be taken. Owing to this method of work holding the work can be removed from the lathe as often as may be desired. If the work has to be mounted again between centers for further treatment, it will rotate about the same axis as before.

2.The two lathe centers are mounted in two spindles: one – the live centre is held in the headstock spindle and turns together with the spindle and the work, the other – the dead centre is head in the tailstock spindle and in most cases does not turn and rubs against the workpiece. Both lathe centers should always be aligned, i.e. the points are to meet when the tailstock with its centre is moved up to the headstock centre.

3.Short parts are usually held in a chuck, i.e. a rotating vice which important varieties of lathe chucks:

· Independent jaw chucks;

· Concentric or self centering chucks;

· Collet or contracting chucks.

An independent four-jaw chuck has four jaws carried in radial slots in the chuck body, each jaw being adjusted independently by means of its own screw. It offers the possibility to fasten works of both cylindrical and non-cylindrical shape in such chucks.

4.The concentric chuck usually has three jaws which can be moved in and out together by means of a chuck key. This chuck is very convenient in operation as all its jaws are moved simultaneously. Consequently a work of cylindrical shape is clamped exactly along the spindle axis. This centering is done automatically, therefore such chucks are called “self-centering”. The jaws of the chuck are made of hardened and tempered steel to prevent their wear. A collet or a contracting chuck is applied for rapid fastening short works of small diameter.

5.Magnetic chucks are adapted to work which is difficult to hold in chuck jaws. The magnetic chucks have no jaws as the work is held by magnetic force instead of by mechanical means. Some workpieces are so shaped that they cannot be held in a chuck, and work of the kind is often clamped to a faceplate. Most lathes are equipped with two faceplates: one small plate is used for driving workpieces turned between centers, and a large one is used to hold heavy or irregularly shaped pieces.

 

XVII. Составьте аннотацию текста.

Text 7

BASIC MACHINE TOOLS

Просмотрите текст и выполните следующие задания.

I. Используя специализированный англо-русский словарь по технологии машиностроения и металлообработке, переведите следующие слова и словосочетания и запомните их:

 

workbench

abrasive wheel/belt

grinding wheel

tolerance

twist drill

to countersink

to tap

groove

to attack, attachment

slot, T-slot

dovetail, dovetail slot

 

II. Переведите следующие именные группы, обращая внимание на перевод слов в функции определения:

 

Huge production machine; metal part; hole-machining operation; surface grinder; surface finishing operations

III. Укажите способ словообразования следующих слов и переведите их на русский язык:

 

Various, variety, variable, relationship, tolerance, abrasive, workbench, available, availability

 

IV. Выпишите из текста интернациональные слова. Проверьте их произношение и перевод по словарю.

V. Найдите в первом и втором абзацах и выпишите слова, которые можно отнести к «ложным друзьям переводчика». Проверьте значение этих слов по словарю.

VI. Выпишите из текста сказуемые в страдательном залоге и переведите их вместе с относящимися к нему словами.

VII. Найдите во втором абзаце герундий, определите его функцию и переведите вместе с относящимися к нему словами.