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:

planer, rail, housing, stroke, rectilinear, machining, work table, brace, slot, cross-rail, side-head, to employ, to cut, to plane, to equip, to bolt, arrangement, adjacent, gang planer tools

II. Answer the following questions:

1. What is a planer? 2. What is the planer used for? 3. Where is the work to be treated on the planer held? 4. What is string planning? 5. Name the main types of planers. 6. What is the main feature of the double-housing planer? 7. By what is ample strength of the housings assured? 8. What are the housings keyed and bolted to? 9. How many cutting heads are the large-size planers provided with? 10. What are the cutting heads mounted on and what are they used for? 11. What operations

is it possible to carry out on planers provided with side-heads in addition to two cutting heads mounted on the cross-rail? 12. What is the work table designed for? 13. What is the construction of the table and what is it made of? 14. How does the work table move?

III. Give derivatives from the following words and translate them into Russian:

relative, to move, to machine, to plane, to attach, rough, flat, brace

IV. Give different meanings of the following words:

plane, head, rib, poor, bed, table, unit, plate, house

V. Supply synonyms for the following words:

surface, to mount, fast, accurate, speed, to determine,

VI. Supply antonyms for the following words:

flat, vertical, open, narrow, fast, high, hard, long, large, heavy

VII. Find the predicates and state the kind of the subordinate clauses in the following sentences and translate them into Russian:

1. A tool apron extends the full width of the slide and is provided with horizontal T-slots running the full width of the apron so that tool holding bolts may be laterally adjusted to properly hold the tool. 2. This construction allows the greatest variety of possible tool positions and, therefore, greatly reduces the number of tool shapes required. 3. The tool frame supporting the tool apron swivels 20 degrees, either side of the center. 4. Index plate swivels on a large bearing which is cast integral with the index, thus giving added stiffness to the index and providing the most rigid construction for resisting the cutting strains. 5. All controls are so completely centralized that the operator can run the entire machine, except for the left-hand side-head, without moving from his normal working position at the end of the cross-rail.

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

1. The planer is a machine for producing flat surfaces on a work. 2. The entire drive from motor to work consists of three gears and one rack. 3. The bed is the strongest construction of the planer. 4. Cross-ribs tie the housings together. 5. The design of the table ways is of great importance. 6. The table is made of alloy iron. 1. The rack is set in a groove machined in the table.

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

The entire drive from motor to work consists of only three gears and one rack. Helical gears are steel, and the spiral gear and rack are both made of high strength alloy iron but of different analysis and hardness so as to provide a combination of materials unsurpassed for strength and wearing qualities. Spiral gear is an involute gear, while the table rack is an involute rack, and the action between them is

equivalent to the action of an infinite number of spur gears and racks. This is the reason why it is the smoothest of all planer drives and it never wears out but always wears in¹. The rack teeth are cut at an angle so that the resultant tool pressures are parallel to the line of motion of the table. This entirely eliminates driving side thrust on the table.

¹. it never wears out but always wears in - никогда не изнашивается, но всегда прирабатывается

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

X. Using the following words and word combinations describe the principle of operation and construction of the double-housing planer shown in Fig. 53:

the double-housing planer, two vertical housings, to be used, rapid roughing and finishing, such work, engine and lathe beds, strength and support, the housings, to be provided, internal bracing, to be keyed and bolted, the bed, to form, a rigid unit, two cutting heads, to be mounted, the cross-rail, to hold tools, to cut material simultaneously, the work, to be planed, to be secured, the table, to be made, alloy iron, to have, top and bottom plates, to be tied together, side walls, center rib, cross-ribs, the upper part, three or more tee slots running lengthwise, numerous holes, to insert stops and clamping blocks, the under side, two accurately machined guides, to slide, guide ways, to move, against one or more cutting tools, to be held, the cross-rail and side-heads, the return stroke, to be constant, no cutting, to take place

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