These are the machines used in engineering to shape metals and other materials.
Before the machine age, this work was done with hardened hand tools, in particular, the chisel and hammer.
It took a long time to obtain the necessary quality and accuracy. The metal was first given roughly its right shape by being either hammered when red-hot or cast in a mold. Then the final shape was obtained by further hammering and by chiseling.
A great advance was made with the introduction of the file, a hardened steel tool, used to smooth the relatively rough surfaces left by the chisel. Nowadays, these hand tools are normally used only for final fitting and adjustment of parts made on machine tools.
The various complicated machine tools now used by engineers are designed to do the same jobs as the hammer, the chisel and the file, but very much more quickly and efficiently, and with much wider range of application. The vastly increased production of modern times would never have been possible without these machines to take the place of handwork, nor could the hand-worker ever produce the precision now needed.
The machine-tools which have replaced the chisel and file and which shape the metal by removing parts of it are shapers, planers, milling machines, drilling and boring machines, grinders and lathes and those which have replaced the hammer and which press the metal into the required shape are steam hammers, forging and pressing machines and sheetmetal work tools.
Слова, словосочетания и специальные термины:
a chisel – зубило, долото .
a hammer – молоток .
a file – напильник .
rough – грубый .
roughly – начерно, грубо .
range of application – диапазон применения .
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a shaper – поперечно-строгальный станок .
a planer – продольно- строгальный станок .
a sheetmetal work tool – машина для листовой штамповки.
Задание 1.2
Прочитайте текст повторно и скажите, какие станки (механизмы) заменили:
а) зубило и напильник,
б) молоток.
Подтвердите свой ответ ссылкой на текст.
Задание 1.3
Перескажите кратко содержание текста «Machine Tools».
TEXT 2 “Metal-Cutting Machines. The Lathe”
Задание 2.1
