Text 6 Methods Of Work Holding

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:

treatment

to rub

lathe centre point

chuck

vice

lathe spindle nose

jaw, independent jaw chuck

self-centering chuck

collet

contracting chuck

slot

screw

to fasten

chuck key

to temper (steel)

faceplate

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

centre holes; spindle axis; chuck jaw; independent four-jaw chuck

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

treatment; variety; concentric; independent; independently; possibility; simultaneously; non-cylindrical; irregularly

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

V. Найдите во втором и третьем абзацах общепринятые сокращения (латинские), дайте их английский эквивалент и переведите на русский язык.

VI. Найдите в тексте случаи употребления слова “as”, определите его функции и переведите его вместе с относящимися к нему словами.

VII. Выпишите из первого абзаца причастие I, определите его функцию и переведите вместе с относящимися к нему словами.

VIII. Выпишите из первого абзаца инфинитив в функции определения и переведите его вместе с определяемым существительным.

IX. Найдите в первом и втором абзацах предложения, в которых глаголы to have и to be имеют модальное значение. Переведите эти глаголы вместе с относящимися к ним подлежащими.

X. Найдите в третьем абзаце предложение с конструкцией “ There + be ” и переведите предложение на русский язык.

XI. Найдите в третьем абзаце предложение с независимым причастным оборотом и переведите его на русский язык.

XII. Выпишите из текста все герундии, определите их функции и переведите на русский язык вместе с относящимися к ним словами.

XIII. Переведите следующие словосочетания, сравнивая перевод причастия I и герундия в функции определения:

measuring instrument –measuring position;

heating device – heating effect;

operating characteristics – operating turbine;

cutting tool – cutting speed;

melting metal – melting point

XIV. Переведите следующие предложения, обращая внимание на функции герундия:

1. Sulphur is hardened by being mixed with a little copper.

2. Heating copper wire from 0 to 100⁰ increases its resistance about 40%.

3. A thin layer of tin prevents rusting.

4. Metals cannot be dissolved without being changed into new substances.

5. In studying the chemistry of phosphorus it will be helpful to recall what we have learned about nitrogen.

6. On changing the magnetic field round a conductor, a current is set up in it.

7. Let us consider a simple drilling operation.

XV. Переведите следующие предложения, обращая внимание на ing -формы:

1. Having been machined with a correctly selected cutting tool the surface of the work was very smooth.

2. Observations were made with high precision measuring instruments.

3. In turning different materials and works of different diameters lathes must run at different speeds.

4. Measuring resistance is necessary in many experiments.

5. When being machined the work revolves around its axis.

6. Iron is covered with a thin layer of tin to prevent it from rusting …

7. Processing operations are those in which the actual cutting process or chip removal takes place.

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

1. When machining a work piece 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 may be attached to the nose of the lathe spindle. There are three 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.

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