8. MACHINE TOOLS

8.1 Before you read the text answer the question:

What types of Machine Tools do you know?

8.2 Read and translate the text.

MACHINE TOOLS

Machine Tools, stationary power-driven machines used to shape or form solid materials, especially metals. The shaping is accomplished by removing material from a workpiece or by pressing it into the desired shape. Machine tools form the basis of modern industry and are used either directly or indirectly in the manufacture of machine and tool parts. Modern machine tools date from about 1775, when the English inventor John Wilkinson constructed a horizontal boring machine for producing internal cylindrical surfaces. About 1794 Henry Maudslay developed the first engine . Later, speeded the wider use of Wilkinson's and Maudslay's machine tools by developing, in 1830, measuring instruments accurate to a millionth of an inch. His work was of great value because precise methods of measurement were necessary for the subsequent of articles having . Machine tools may be classified under three main categories: conventional chip-making machine tools, presses, and unconventional machine tools. Among the basic machine tools are the lathe, the shaper, the planer, and the milling machine. Auxiliary to these are drilling and boring machines, grinders, Tunnel boring machine saws, and various metal- forming machines. Conventional chip-making tools shape the workpiece by cutting away the unwanted portion in the form of chips. Presses employ a number of different shaping processes, including shearing, pressing, or drawing (elongating). Unconventional machine tools include plasma-arc, laser-beam, electrodischarge, electrochemical, ultrasonic, and electron-beam machines. They were developed primarily to shape the ultrahard alloys used in heavy industry and in aerospace applications and to shape and etch the ultrathin materials used in such electronic devices as microprocessors. 8.3 Match these words with the appropriate explanation

1. workpiece a. a power-driven machine, such as a lathe, miller, or grinder, that is used for cutting, shaping, and finishing metals or other materials 2. b. a machine that applies pressure to a workpiece by means of a tool, in order to punch shapes 3. measurement c. of or involving sound waves with a frequency above the upper limit of human hearing 4. interchangeable d. an object being worked on with a tool or machine 5. press e. a mechanical power-driven tool for cutting which has a toothed rotating disc or moving band 6. boring machine f. based on or in accordance with what is generally done or believed 7. saw g. the act or process of measuring 8. conventional h. the manufacture of large, heavy articles and materials in bulk 9. ultrasonic i. a large vertical lathe having a rotating table on which work is secured. Tools are held on a fixed post and the work is rotated around it 10. heavy industry j. apparently identical; very similar

8.4 Mark the sentences with T if they are true and with F if they are false

1. Machine Tools are very ancient inventions and don’t exist any more

2. Machine tools are used in the manufacture of machine and tool parts.

3. Joseph Whitworth developed measuring instruments accurate to a millionth of an inch. 4. Conventional chip-making tools shape the workpiece by cutting away the unwanted portion in the form of chips. 5. Unconventional machine tools include shearing, pressing, or drawing.

8.5 The word it in paragraph 1 refers to 1. metals 2. material 3. workpiece 4. shape 5. basis 8.6 The word these in paragraph 3 refers to 1. basic machine tools 2. boring machines 3. metal-forming machines 4. conventional chip-making tools 5. saws

8.7 The word they in paragraph 3 refers to 1. conventional chip-making tools 2. unconventional machine tools 3. presses 4. ultrahard alloys 5. ultrathin materials

8.8 Match the inventions 1-3 with their inventors

John Wilkinson Henry Maudslay Joseph Whitworth

1. constructed a horizontal boring machine 2. developed the first engine lathe. 3. developed measuring instruments accurate to a millionth of an inch.