Words and word combinations
computer numerical control (CNC) – числове програмне управління (ЧПУ)
the engine lathe – фасонний токарний верстат
cutting operations – токарні операції
a template – шаблон
knurling – нанесення насічок
a spindle – шпиндель
0°-90° – from zero to ninety degrees
Exercises
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
A
ll
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.