Of Drilling Machines

Drilling machines are designed for producing through and blind holes in solid material, for finishing (core drilling and reaming) rough holes made in the blank by drilling or other methods, as well as for tapping threads, counterboring, countersinking and spot-facing.

Employing special tools and attachments, drilling machines can be used to bore holes, cut out large holes in sheet metal by trepanning, lap precise holes and other operations.

Drilling machines find applications in machine, assembly and repair shops and in toolrooms of engineering plants, as well as in maintenance departments servicing transportation facilities, building and agricultural machinery.

Holes are machined in drilling machines with twist drills, core drills, reamers, countersinks, spotfacers and other tools; threads are cut with taps.

The following types of general-purpose drilling machines are available: (1) bench-type drill presses (single-spindle); (2) upright drill presses (single-spindle); (3) radial drills; (4) gang drills; (5) deep-hole drilling (horizontal-drilling) machines.

Most widely used in the general engineering industries are the upright drill press and the radial drill.

The principal dimensions of a drilling machine are the drilling capacity in steel of medium hardness with a tensile strength of Q=50-60 kg per sq mm, the size of the taper in the spindle socket, the distance from the spindle center to the face of the column (overhang), and the distances from the spindle nose to the table and to the base.

EXERCISES

1.Answer the following questions, using the information from the text:

1. What are drilling machines designed for?

2. What kind of holes can be bored in drilling machines?

3. Where do drilling machines find their applications?

4. What tools are employed for machining holes in drilling machines?

5. What are the most widely used types of drilling machines?

6. Can you name other types of them used in industry?

7. What are the principal dimensions of drilling machine?

2.Translate the following groups of words, paying attention to the meaning of suffixes:

Precise, precision; general, generally, generation; producing, production, produce; employ, employing, employment; finish, finishing, finished; special, speciality, specialize, specialization; operate, operation, operational, operative; machine, machined, machinery.

3.Fill in the blanks with the preposition: for, of, in, with, by, out, from, to:

1. Drilling machines are designed... producing through and blind holes... solid materials.

2. Employing special tools drilling machines can be used to cut... large holes... sheet metal... trepanning.

3. The distance... the spindle centre... the face... the column is one... the principal dimensions... a drilling machine.

4. Holes can be machined... twist or core drills.

5. The drilling capacity... 50 to 60 kg per sq mm is considered to be the main dimension... a drilling machine.

4. Find the English equivalents for the following:

Cтанок для глубокого сверления, вертикально-сверлильный станок, радиально-сверлильный станок, тонколистовой метал, цековка, метчик, развертка, сталь средней твердости, лицевая сторона стойки, механический цех, сборочный цех, ремонтный цех, инструментальный цех, сервисная служба, передний конец шпинделя, сельскохозяйственное оборудование, заготовка.

5.Supply the missing word:

1. In drilling h... in metal, different t... can be employed.

2. Threads are cut with t....

3. T... and b... holes can be produced in solid material.

4. Rough holes are made in the b... by drilling.

5. Drilling machines find application in machine, assembly and repair s...

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