Lesson 8 Drilling Machines Part 3

Power-Feed Drilling Machines. The power-feed drilling machines are usually larger and heavier than the hand-feed. They are equipped with the ability to feed the cutting tool into the work automatically, at a preset depth of cut per revolution of the spindle, usually in thousandths of an inch per revolution.

These machines are used in maintenance shops for medium duty work, or work that uses large drills that require power feeds. The power-feed capability is needed for drills or cutting took that are over 1/2 inch in diameter, because they require more force to cut than that which can be provided by using hand pressure. The speeds available on power-feed machines can vary from about 50 RPM to about 1,800 RPM. The slower speeds allow for special operations, such as counterboring, countersinking, and reaming.

The sizes of these machines generally range from 17-inch to a 22-inch center-drilling capacity, and are usually floor mounted. They can handle drills up to 2 inches in diameter. Larger workplaces are usually clamped directly to the table or base using T-bolts and clamps, while small workplaces are held in a vise. A depth-stop mechanism is located on the head, near the spindle, to aid in drilling to a precise depth.

Radial Arm Drilling Machine

This is probably one of the most popular types of drilling machine. Due to its radial orientation, the radial arm drilling machine provides a great deal of versatility in its operation. The set-up of this drilling machine allows the operator to manipulate the machine over the workpieces, thus making it more convenient to operate and drill on large workpieces. Moreover, the radial arm drilling machine can be coupled with a tilting table for the drilling of intersecting and angular holes.

Special Purpose Drilling Machine

This drilling machine is used for special purposes including that of drilling multiple holes at one setting. Intricate tasks such as the drilling of very small holes can also be performed by the special purpose drilling machine. Some of the special purpose drilling machines include the Micro-Drill Press, Multiple Spindle Drilling Machine, and the Turret Type Drilling Machine.

Vocabulary

Preset - с предварительной установкой

per revolution - за один оборот

medium duty work – средний режим работы

power feed - автоматическая подача

clamp – прикреплять, зажимное приспособление, лапка, зажим

T-bolts - болт с T-образной головкой

vise – держатель, тиски

versatility - многоплановость 

tilting table - кантователь; наклонный стол, опрокидываемый стол

at one setting - с одного установа (на станок)

turret type drilling machine - сверлильный станок с револьверной головкой

RPM= Revolutions Per Minute 

Exercise 1

Find Russian equivalents to the following words in the text. Learn them by heart.

Оборудованный чем-то, помогать/способствовать/средство/помощь, значительное количество, многоплановость (в чем-то), более, доступный/ имеющийся в наличии, варьироваться от...до, для особых целей, способность/функциональная возможность, прикреплять/зажим, радиальный/радиус

Exercise 2

Match the words to their definitions.

1) versatility 2) equip with 3) capability 4) a great deal of 5) over 6) aid

a) higher or more than (a specified number or quantity) b) supply with the necessary items for a particular purpose c) help or support (someone or something) in the achievement of something: d) the ability to adapt or be adapted to many different functions or activities e) a large amount f) the power or ability to do something

Exercise 3

Translate these sentences from Russian into English

1) Все спальни оборудованы цветными телевизорами.

2) Я присоединил мотор к столу двумя зажимами.

3) Берега этих островов обычно песочные, но температура более 30 градусов редка.

4) Просмотрите все доступные места на ваш следующий полет компании American Airlines.

5) Цены сильно варьируются в зависимости от (depending on) времени года и вида жилья.

Exercise 4

Answer the questions

1) What is the difference between power-feed and hand-feed machines?

2) Where are power-feed machines used?

3) What is the size of power-feed machines?

4) Why does a Radial Arm Drilling Machines provide a great deal of versatility in its operation?

5) What is used for the drilling of intersecting and angular holes?

6) What are Special Purpose Drilling Machines used for?