Ex.6. Read and translate the text.

Text A

Drilling machines

Drilling machines are very old machines tool mainly employed for drilling holes of different size in metal or any other solid material. In addition to drilling holes, such operations as tapping, reaming, countersinking and counter boring may be performed n the drilling machines. Since drilling machines are used for a great variety of operations they are divided into various classes such as: upright or vertical spind1e, multiple-spindle, and radial-spindle machines. In all three types the drill spindle rotates in a sleeve or quill which does not rotate but is free to move axially to provide the necessary feed for the drill.

In vertical spindle drilling machines the spindle is in a vertical position. The upright drilling machine has an upri­ght column resting on a heavy base. The column equipped with a gearbox providing a wide range of speeds has a feed mecha­nism. The feed mechanism represents a feed shaft with its necessary gearing by which the drill is cut into the work at a proper speed.

Since in the upright drilling machines the spindle sleeve supports are fixed, all adjustment for different classes of work is made by moving the table which is accomplished by tu­rning the crank. The table can be moved in a horizontal pla­ne, clamped at any point so that the large work may be placed on the base. The machine is also equipment with a ratchet le­ver for hand feeding the drill.

The upright drilling machines are classified as: heavy duty; plain and sensitive. The heavy duty drilling machine is used for heavy drilling, the plain vertical spindle machine being employed for lighter work. The sensitive drilling machine is a vertical or upright machine of comparatively light cons­truction adapted to very high speeds of drilling holes in delicate works.

The multiple-spindle drilling machines are built in both vertical and horizontal types. Saving considerable time and space this machine is used for simultaneous drilling of many holes in a large number of work pieces. The machine may have a number of movable drills, all the spindles being driven from the same shaft by a worm gear. One of the types of the multiple-spindle machines is the fully automatic machine re­quiring only push-button operation. The machine is provided with a large number of spindles ranging from four to a hundred.

The radial drilling machine has a vertical column mounted on a cast iron base. The column carries a radial arm which moves; not only in a horizontal plane, but may also be moved in a vertical plane.

The drill can be moved over the work to any desired position so that many holes may be drilled in the work without moving it from one place to another. The radial drilling machine is therefore adapted to heavy work where it is easier to move the drill than the work.

 

III. Language.

Ex.7. Match word and word combinations in column A with those in column B:

А	В
a) втулка b) черв’ячна передача c) крихкі заготовки d) використовувати e) коробка швидкостей f) регулювання g) колона h) храповий важіль i) верстат підвищеної точності j) простий фрезерувальний верстат	1. employ 2. gearbox 3. column 4. adjustment 5. ratchet level 6. plain machine 7. sensitive machine 8. delicate works 9. quill 10. worm gear

Ex.8 Find the right ending of the sentences and translate these sentences:

1. Drilling machine is mainly employed for…

a) providing the necessary feed for the drill;

b) drilling holes of different sizes in metal or any other solid material;

c) producing grinding and milling operations.

2. Besides drilling holes drilling machine may perform such operations as …

a) threading, grinding, milling;

b) turning, finishing surfaces;

c) tapping, reaming, lapping, countersinking and counterboring.

3. In the upright drilling machine the spindle is …

a) in a in a horizontal position;

b) in a vertical position.

4. The upright drilling machine has …

a) a feed shaft with its necessary gearing;

b) an upright column resting on a heavy base;

c) a number of movable drills.

5. The feed mechanism represents …

a) a feed shaft with its necessary gearing;

b) a gearbox providing a wide range of speeds;

c) a sleeve or quill which does not rotate.

6. The machine is also equipped with

a) a hand wheel which is fastened to a worm gear;

b) a ratchet lever for hand feeding the drill;

c) a drilling head mounted on the top of the column.

7. The upright drilling machines are classified as:

a) vertical spindle;

b) multiple-spindle, radical spindle;

c) heavy drilling.

8. The heavy duty drilling machine is used for …

a) drilling small holy;

b) accurate drilling;

c) heavy drilling.

9. The sensitive drilling machine is adapted …

a) for drilling holes in solid material;

b) for drilling holes in delicate works;

c) for drilling holes of different sizes.

Ex.9. Fill in the blanks using the following words.

a) quill; b) simultaneous; c) push-Sutton; d) multiple-spindle; e) reaming; f) mounted.

1. In addition to drilling holes such operations as tapping, …, lapping maybe performed on drilling machines.

2. Drilling machines are divided into various classes,…, radial spindle.

3. In all there types the drill spindle rotates in a … which is free to move axially.

4. Saving considerable time and space this machine is used for… drilling of many holes in a large number of workplaces

5. Fully automatic multiple-spindle drilling machine has a vertical column … on a cast iron base.

6. The radial drilling machine has a vertical column … on a cast iron base.

Ex.10. Put question to get the following answers.

1. Such operation as tapping, reading, lapping, countersinking and counterboring may be performed on the drilling machines.

2. In vertical spindle drilling machines the spindle is in a vertical position.

3. The upright drilling machines are classified as: heavy duty, plain and sensitive.

4. Saving considerable time and space the multiple-spindle drilling machine is used for simultenuous drilling of many holes in a large number of workpiues

5. The radial drilling machine has a vertical column mounted on a cast iron base.

 

IV. Comprehension.

Ex.11 Agree or disagree with the following statements:

1. Drilling machines are divided in to various classes such as: upright or vertical spindle, multiple-spindle and radial-spindle machines.

2. The upright drilling machine has a horizontal column resting on a heavy base.

3. The table cannot be moved in a horizontal plane.

4. One of the types of the multiple-spindle machines is the fully automatic machine requiring only push-button operation.

5. The machine is provided with a large number of spindles ranging from forty to a hundred.

6. The radial drilling machine has a vertical column mounted on a tin base.

Ex.12 Answer the question:

1. What are drilling machines used for?

2. Where das the drilling machine spindle rotate?

3. How is the spindle sleeve move?

4. What does the feed mechanism of the drilling machine consist of?

5. What does the ratchet lever serve for?

6. How is the sensitive drilling machine called?

7. What is the plain vertical spindle machine employed for?

8. What are multiple-spindle drilling machines and what are they used for?

9. What main parts does the radial drilling machine consist of?

10. For what type of work is the radial drilling machine adapted?

Ex.13 Fill in the tables:

 

Drilling machines

 

V. Oral practice.