Контрольні питання

1. Утворення теперішнього неозначеного часу пасивного стану.

2. Яку дію означає цей час?

Література: [1, с. 91-95; 2, с. 99-105; 3, с. 160-199; 4, с. 70-74; 5, с. 85-89]

Практичне заняття 28, 29, 30 Various Types of Machines

Тема: Various types of machines

Мета: вивчення лексики з фаху, майбутнього неозначеного часу пасивного стану.

Короткі теоретичні відомості

1. Memorize the following words

shape	фасонувати, фор­мувати	maintain	зберігати, утриму­вати
tool holder	різцетримач	cutting edge	різальний край
work holder	тримач заготовки	friction temperatures	підвищення темпе­ратури внаслідок тертя
slide	золотник (стіл)	cutting operation	процес різання
table	стіл (золотник)	high-speed steel	інструментальна сталь
feed	подавати (заготов­ку)	nonferrous	кольоровий (метал тощо)
fixed speed	стала швидкість	alloy	сплав
cutting (shaping) tool	різець	tungsten	вольфрам
stationary	нерухомий	diamond	діамант
means of controlling	засоби контролю	lubricate	змащувати
angle	кут	chromium	хром
rate	швидкість	cobalt	кобальт
workpiece	заготовка (заго­товка); деталь, що обробляється	ceramicized alumi­num oxide	керамізований окис алюмінію

2. Read and translate the text.

The early machine tools were largely invented in England. Henry Maudslay's inven­tion (1797) of a constant-speed screw cutting machine permitted identical screws to be mass produced. Improvements to the lathe were made by a number of machinists, including Joseph Whitworth, who became a leading manufacturer of machine tools. Planing, milling, and shaping machines-many similar to some in use today-were invented in England during the first half of the 19th century by a group of extraordinarily talented men, many of whom had worked with Maudslay.

In the United States the lathe and various types of gear-cutting and grinding machines were all introduced before 1850. Although small gear-cutting machines had long been used, improved machines began to appear during the 1830s and 1840s both in England and in America. By 1850 the basic types of grinding machines were all in use, and grind­ing technology was limited only by the lack of suitable abrasives, many of which were invented during the latter part of the 19th century. The first milling machine was the inven­tion (1818) of Eli Whitney, and milling machines for industrial use were being produced by the 1850s. In fact, by mid-century, machines had been devised that could carry out all the basic machine-tool operations. Later developments were largely confined to refining these operations, such as increasing machine speed and inventing cutting materials that would keen their edge at higher temperatures.