I. Find the Gerund and state its function.

1. The device for measuring the strength of current is called ammeter.

2. He succeeded in performing the experiment.

3. We can increase the current by reducing the resistance of the circuit.

4. We didn't know of his having made the experiment.

5. Wash minor wounds and grazes with soap and water and follow this by applying an adhesive dressing.

6. By analyzing the brightness of the lumi­nescence they estimated the amount of bacteria in the leaf.

7. The analysis of the phenomenon was very useful in helping us to understand the ways Qf nature and our ways of looking at it.

8. Airplanes and helicopters can become highly electrically charged either from flying through dast or snow or from encountering strong electric fields in clouds.

II. Explain the meaning of the international prefixes. Give the Ukrainian equivalents.

• co-author, co-worker, co-operation
• antiparticle, antipathy, antidote
• decode, degenerate, dehydrate, depopulate
• extravagant, extracellular, extraordinary
• ex-president, ex-king, exchange, export
• prefabricate, predecessor, predestine, prearrange
• supernatural, superstructure, superhard
• transform, transplant, translocation
• ultradense, ultramodern, ultra-short

 

 

Text 11

LATHE TOOLS

All machine tools that use metal to shape metal have similar parts to carry out the shaping process: a tool-holder, to keep the shaping tool in place; and a work holder, called a table or compound slide, to hold the part that is to be shaped and to move or feed it at a fixed speed against the tool. In some machines the table is stationary, and the tool moves. In addition, a means of controlling the rate and angle at which the tool cuts the work-piece must be provided. Both the speed of feed and the position of the work-piece and the tool in relation to each other can be varied. Cutting tools must be made of materials that are harder than the metals and are capable of main­taining their cutting edge at friction temperatures that result from the cutting operation. The most common materials used are high-speed steel (H.S.S.); non-ferrous metals containing tungsten, chromium, and cobalt; ceramicized aluminum oxide; and diamonds.

Round-nosed tools (see picture below) give a fine finish whilst knife tools are necessary to work sharp corners. Grinding lathe tools demands great care and skill since the angles – top rake and clearance – have to be correct for each of the different kinds of metal being turned.

For efficient cutting, the cutting edge of the tool has to be aligned carefully with the axis of the work up to the centre line. To reduce overheating, tool wear and to lubricate the cutting area, coolants are often used when turning. Water and soluble oil mixed to a milky-looking solution is commonly used.

There are various ways of setting up the lathe. For facing-off a three or four-jaw chuck is used. Parallel turning on long lengths is carried out between centres, the material being supported at both ends. For holding irregular shaped work, a face plate is used.

 

Words and word combinations

a tool-holder = the tool post – різцетримач

compound slide – супорт

сutting tools = tools – різці

high-speed steel (H.S.S.) – швидкоріжуча (інструментальна) сталь

grinding lathe tools – шліфувальні (абразивні) токарні інструменти

setting up – налагодження

facing-off – обточування торця

chuck – зажимний патрон

centres – центрові отвори

a face plate – планшайба

EXERCISES

I. Give the Ukrainian equivalents.

 

1) 82.75 ………………………

2).0³8 …………………………

3) 75 P. C. …………………….

4) 3 lbs ………………………..

5) 5 yds ……………………….

6) 10 in ………………………..

7) gr ……………………………

8) e. g. …………………………

9) D. C. ………………………..

10) 1 ft. ………………………..

 

II. Translate into Ukrainian paying attention to the numerals.

1. The distance to the Moon is 239,000 miles.

…………………………………………………………………………………………………………………………………………………………………………………………………………

2. The distance to the Sun is 90,000,000 miles.

…………………………………………………………………………………………………………………………………………………………………………………………………………

3. The plane flew at the altitude of 30,000 ft

………………………………………………………………………………………………………………………………………………………………………………………………………….

4. I need the U. S. Patent No. 4,861,437.

………………………………………………………………………………………………………………………………………………………………………………………………………….

5. The wall was 10.3 in thick.

…………………………………………………………………………………………………….

6. The motor operates at a rate of ca 2,000 r. p. m.

…………………………………………………………………………………………………………………………………………………………………………………………………………

III. Make up a dialogue using the questions to Text 9.

 

Text 12

MODERN MACHINE TOOLS

Modern machine tools are capable of processing ultrahard metals not machinable by other methods. Machine tools that form parts by removing metal chips from a work-piece include lathes, shapers and planers, drilling machines, milling machines, grinders, and power saws. The cold forming of metal parts, such as cooking utensils, automobile bodies, and similar items, is done on punch presses, while the hot forming of white-hot blanks is done on forging presses. Modern machine tools cut or form parts to tolerances of plus or minus one ten-thousandth of an inch (0.0025 millimeter). In special applications, precision lap­ping machines can produce parts that are within plus or minus two millionths of an inch (0.0³5 millimeter). Because of the precise dimensional requirements of the parts and the heavy cutting forces exerted on the cutting tool, machine tools combine weight and rigidity with delicate accuracy.

 

EXERCISES

I. Give the Ukrainian equivalents:

1.	machinable
2.	metal chips
3.	shapers
4.	planers
5.	grinders
6.	power saws
7.	cold forming of metal parts
8.	punch presses
9.	hot forming of white-hot blanks
10.	forging presses
11.	tolerances
12.	lap­ping machines
13.	precise dimensional requirement