Exercises. I. Use the following words and phrases in sentences of your own:

I. Use the following words and phrases in sentences of your own:

bench lathe, turret lathe, to bore, engine lathe, carriage, cross-slide, rigid, bed, change gearbox, to revolve, sleeve, to advance, handwheel, to retract, feed mechanism, feed shaft, to actuate, feed, apron, to swing

II. Retell the text giving answers to the following questions:

1. What is a lathe? 2. What operations may be performed on a lathe? 3.What devices enable grinding and milling operations on a lathe? 4. With respect to what characteristic features are lathes classified? 5. What types of lathes are mentioned in the text? 6. What kind of work is the bench lathe intended for? 7. What are turret lathes? 8. Why are some lathes termed chucking lathes? 9. What are automatic lathes? 10. What lathes belong to special-purpose lathes? 11. What basic parts does the engine lathe consist of? 12. What is the function of the lathe bed? 13. What is the upper surface of the bed provided with? 14. What do the bed ways serve for? 15. Which side of the bed is the headstock bolted to? 16. What does the change gearbox serve for? 17. What is the tailstock and where is it located? 18. Which bed ways does the tailstock slide along?

III. Choose antonymical groups out of the following list:

dead center, alignment, regular, right feed, fasten, disalignment, irregular, left feed, easy, to prohibit, unfasten, live center, difficult, to permit

IV. Change the sentences using the "Nominative with the Infinitive" and then translate them into Russian:

Example: It is known that the lathe is the most important machine tool used for machining surfaces of a workpiece.

The lathe is known to be the most important machine tool used for machining surfaces of a workpiece.

1. It is known that the lathe is regularly furnished with a multiple disc clutch and brake incorporated in a driving pulley. 2. It is intended that the compound rest slide is actuated by a screw rotating in a nut fixed to the saddle. 3. It is known that the headstock and the tailstock are fastened at opposite ends of the lathe bed. 4. It was said that the independent chuck had been suitable for almost any type of work. 5. It seems that this new feed mechanism is simple and easy to operate. 6 It proved that the functions of the new lathe were fully automatic. 7. It was evident that the engine lathe has been widely used for metal-turning operations.

V. Make up questions to which the italicized words are the answers:

1. The lathe is a machine tool for machining surfaces of a round workpiece. 2. The tailstock of a lathe rests on a saddle. 3. The lathes are generally furnished with brakes. 4. To start the spindle one can use either the head or apron control. 5. The cross-slide is mounted on the carriage. 6. The tool holder is clamped by the tool post screw. 7. The feed mechanism comprises a cone of gears, an intermediate shaft and a set of sliding gears. 8. The change shifter slides on a splined shaft and carries a tumbler gear.

VI. (a) Read and translate the following text without using a dictionary:

The automatic lathe is designed so that all of the tool movements are automatically controlled, although the work must be inserted and removed by an operator. In the automatic lathe two or more heavy duty slides, each with its own drive, rate of feed and direction of feed, may be applied. All functions of the machine are completely automatic, including advance of the platen to working position, feeding of all tools, and retraction of slides and platen at completion of cycle, at which time stopping of the spindle is also accomplished automatically. One operator may run two or more lathes. Such lathes are not limited to automotive parts but are reducing production time and cost on pump parts, motor and generator parts, pipe flanges, brass and bronze castings, chuck bodies, bevel gears, airplane engine cylinders, etc.

(b) Make up questions on the basis of this text and answer them.

VII. Giving answers to the following questions describe the construction of the spindle shown in Fig. 49 and the bed shown in Fig. 48:

1. What part of the lathe is a spindle and what purpose is it intended for? 2. What kind of shaft does a spindle represent? 3. For what purpose is a spindle supplied with a taper bore? 4. What has to be done with the nose of a spindle for the chuck to be screwed on it? 5. What does the lathe bed serve for? 6. What kind of walls is the bed supplied with? 7. How are the walls of the bed connected? 8. What is the function of the bed ways?

VIII. Using the following words and word combinations describe the construction of the tailstock shown in Fig. 50:

a casting, to consist, the tailstock, to be fitted to the bed, to carry, a non-rotating sleeve, to be advanced, the revolving screw, to operate, the handwheel, to move along the lathe bed, to be of the V-section, a hollow spindle of the tailstock sleeve, to be provided, a standard taper bore, to hold the lathe centers, the tailstock spindle, to be graduated, to facilitate measurement, the spindle travel

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