Е. С. Закирова, П. А. Красавин Английский язык для технических вузов
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T A Karpova Anglysky dlya tekhnicheskikh vuzov (1)
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- MODULE 10 BUSES AND COACHES
| MODULE 9
A LATHE The turning processes are typically carried out on a lathe. It is consid- ered to be the oldest machine tool. A workpiece of some material is rotated on a lathe so that when abrasive, cutting or deformation tools are applied to the workpiece, it can be shaped to produce an object with the rotational symmetry about an axis of rotation. Turning usually uses simple single-point cutting tools. The operations that can be performed with a single-point tool on a lathe are chamfering, parting, threading, boring, drilling, knurling. A lathe can be of four different types such as straight turning, taper turn- ing, profiling and external grooving. They can produce various shapes of work- pieces, such as straight, conical, curved, and grooved. Each group of work- pieces has an optimum set of tools operations which have been developed through the years. Modern computer numerical control (CNC) lathes and CNC machining centres can do also other operations, e.g. milling by using driven tools. Most modern CNC lathes are able to produce most objects in 3D. MODULE 10 BUSES AND COACHES Buses (also called omnibuses) are designed to transport about forty pas- sengers. In towns and cities there are usually short distances between stops, 277 and speed of loading and unloading passengers is very important. The entrance step to the bus is about 300 mm above the road and it provides an easy step up. Another step up leads to the deck of the bus. The doors are usually power- operated by the driver to prevent passengers getting on or off while the bus is moving. A double-decker bus is carrying about sixty passengers. In modern designs the entrance is at the front for the driver to have a direct view of board- ing passengers. A coach is a type of a bus for conveying between thirty and forty passen- gers on excursions or for fairly long distances between towns and even coun- tries. Unlike buses designed for shorter journeys, coaches have a luggage hold separate from the passenger cabin and are normally equipped with facilities re- quired for longer trips: comfortable seats, air-conditioning, overhead luggage compartments, small tables for small snacks, video screens to show movies, and sometimes even a toilet. жүктеу/скачать 4,38 Mb. Достарыңызбен бөлісу:
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