Ex.24. Describe the structure of the drill press.

Ex.25 Explain: why it is necessary to know the size of swing:

Supplementary reading

Texts for a written translation with a dictionary.

Read the texts and translate them in writing. Use a dictionary.

Text D

Pistol-grip (corded) drill

A drill in the shape of a pistol is today a useful and ubiquitous type of power tool. There is an endless variety of subtypes of this basic form factor, with the notable exception being the Right Angle Drill, a specialty tool used by trade specialists such as plumbers and electricians.

For much of the 20th century, many attachments could commonly be purchased to convert corded electric hand drills into a range of other power tools, such as orbital sanders and power saws, more cheaply than purchasing conventional, self-contained versions of those tools (the greatest saving being the lack of an additional electric motor for each device). As the prices of power tools and suitable electric motors have fallen, however, such attachments have become much less common. A similar practice is currently employed for cordless tools where the battery, the most expensive component, is shared between various motorised devices, as opposed to a single electric motor being shared between mechanical attachments.

Text E

Hammer drill

The hammer drill is similar to a standard electric drill, with the exception that it is provided with a hammer action for drilling masonry. The hammer action may be engaged or disengaged as required.

The hammer action is provided by two cam plates which makes the chuck rapidly pulse forward and backward as the drill spins on its axis. This pulsing (hammering) action is measured in Blows Per Minute (BPM) with 10,000 or more BPMs being common. Because of the relative masses of the chuck+bit and the remainder of the drill the energy transfer is relatively inefficient and can sometimes make it difficult for larger bits to penetrate harder materials such as poured concrete. Vibration is quite noticeable by the operator, and the cams are generally made from hardened steel to avoid them wearing out quickly. Most electic hammer drills are rated at between 6.3 and 9 amps, and are restricted to standard masonary bits 1/2 inch in size maximum. A typical application for a hammer drill would be to install electrical boxes, conduit straps or shelves in concrete.

Compare this to a rotary/pneumatic hammer drill where just the bit is accelerated to the work. This is accomplished through a piston design, rather than a spinning cam. Rotary hammers have relatively little vibration and penetrate most building materials. They can also be used as "drill only" or as "hammer only" which extends their usefulness for tasks such as chipping brick or concrete. Hole drilling progress is greatly superior to cam type hammer drills, and these drills are generally used for holes of 3/4 an inch or greater in size. A typical application for a rotary hammer drill would be to bore large holes for lag bolts in foundations, or to install large lead anchors in concrete for handrails or benches.

A standard hammer drill accepts 1/4 inch and 1/2 inch drill bits, while a rotary hammer uses SDS or Spline Shank bits. These heavy bits are adept at pulverising the masonry and drill into this hard material with relative ease.

However there is a big difference in cost. In the UK typically £12 upward for a cam hammer and £35 up for a rotary/pneumatic. In the US a typical hammer drill will cost between $70 and $120, and a rotary hammer between $150 and $500 (depending on bit size). For DIY use or to drill holes less than 1/2 inch in size, the hammer drill is most commonly used.

Text F

Rotary hammer drill

A rotary hammer drill used in construction

 

The rotary hammer drill (also known as roto hammer drill or masonry drill) is an electric drill type dedicated to drilling holes in masonry. The rotary hammer drill is a percussion drill that uses a weight to create the impact force on the masonry bit. Generally, the drill chuck of the rotary hammer drill is designed to hold SDS drill bits. Some styles of this drill are intended for masonry drilling only and the hammer action cannot be disengaged. Other styles allow the drill to be used without the hammer action for normal drilling, or hammering to be used without rotation for chiselling.

 

 

Unit 12

Milling machines

I. Language.

Ex.1. Remember the following words and word combinations:

milling machine-фрезерний верстат - фрезерний станок

to remove- видаляти, усувати - удалять

cutter- фреза/різець - фреза/резец

column and knee machine- консольнофрезерний верстат – консольнофрезерний станок

bed type of machine-верстачний фрезерний верстат – верстачный фрезерний станок

planer milling machine- поздовжнофрезельний верстат – продольнофрезерный станок

rotary machine- ротаційний верстат – ротационный станок

horizontal plain machine- горизонтальнофрезерний верстат – горизонтальнофрезерный станок

universal spindle milling machine- універсальний фрезерний верстат – универсальный фрезерный станок

concrete-бетон - бетон

to withstand – вистояти, витримати - выдерживать

weight - вага - вес

to contain- містити - содержать

coolant tank – охолоджувач - охладитель

cutting fluid – охолоджуюча рідина, що змазує - смазывающе-охлаждающая жидкость

to deliver - постачати – подавать, нагнетать

pump – насос - насос

pad- подушка, прокладка - подушка, прокладка

valve- клапан - клапан

outlet nozzle- випускне (вихідне) сопло, отвір – выпускное (выходное) сопло

to swivel – обертатися - вращаться

supply- постачання, подання – снабжение, подача

perforated- перфоруючий, дірчастий – перфорированный, дырчатий

feed gearbox- коробка подання – коробка подач

power feed- механічне подання - механическая подача

change gears- коробка змін швидкостей - коробка перемен скоростей

to shift- перемикатися, зрушувати - переключать, сдвигать

spindle speed change lever- рукоятка управління коробки швидкостей – рукоятка управления коробки скоростей

train- зубчата передача – зубчатая передача

to secure- зміцнювати, з’єднувати – закреплять, соеденять

overarm – підтримуючий рукав фрезерного верстата - поддерживающий рукав фрезерного станка

bar- брусок - брусок

knee- коліно - колено, кронштейн

elevating screw- підйомний гвинт – подъемный винт

feed rate- швидкість подання – скорость подачи

nose- передній кінець, виступ – передний конец, выступ

saddle- полозка - салазка

 

Ex.2. Read the international words and guess their meaning:

a) style, massive, tank, regulate, perforated, manual, to form, antifriction, nose, column, steel, condition, position, mount, nature, diameter, operator, delicate, finish, result, fix.

b) translate these words using the above-mentioned international words:

становище, бак, дірчастий, природа, кінцева обробка, утворювати, установлювати, тонкий, ручний, виступ.

Ex.3. Translate these words paying attention their suffixes: principle-principal; long-longitudinal; horizon-horizontal; to obtain-obtainable; automatic- automatical-automatically; to cut-cutting-cutter; to depend-dependent-dependently; to add-addition-additional.

 

Ex.4. Find the meaning of the following polysemantic words. Translate the sentences:

result

1. Good results were obtained with new device. 2. Sometimes experiments result in great discoveries. 3. Heat results from chemical changes.

 

fix	1. We tried to fix our attention on lecture but it was too noisy. 2. Constant fixed prices are very important for the well-being of people. 3. This idea is fixed in his mind. 4. We bought a new bookshelf and fixed it to the wall.

 

fit	1. This suit fits you well. 2. The cost doesn’t fit me. 3. The door fits badly.

 

 

II. Reading.

Ex.5. Read and translate the text:

Text A Milling machines

1. Milling machines are used for milling operations. Milling is the process of removing material from work with a multi-toothed rotating cutter. There are various classes and types of milling machines in use, from small hand-operated types to fully automatic ones, the main of them being: column and knee type, bed type, planer type, and rotary type. Column and knee type, milling machines are made in three styles: horizontal plain, vertical and universal spindle milling machines.

2. The horizontal milling machine is provided with a massive column rising from a base which rests on a solid wooden or con­crete floor which is sufficiently heavy to withstand the weight of the machine. The base, hol­low inside, contains a coolant tank with cutting fluid that is delivered through piping by means of a motor-operated pump to the cutters. The centrifugal type pump is mounted on the pad located at the side of the base and is connected directly to the coolant tank. The cutting fluid flow can be regulated by means of valves connected to the outlet nozzles which can be swivel­led for distributing a low pressure volume of cutting fluid to all diameter and types of cutters. A constant supply of clear oil is pumped to the column and feed gearbox. In the lower part of the column there is a motor for driving the spindle and the change gears for the power feed. A set of change gears for dri­ving the spindle at a proper speed is housed in the upper part of the column. The change gears are shifted either manually by a spindle speed change lever or by power to form various trains for providing the necessary cutting speeds.

3. The horizontal plain milling machine has a horizontal spindle rotating in anti-friction bearings in the column. The spindle is a hardened, ground, hollow shaft spaced horizontally from the front to the back of the column. Secured to the top of the column is an overarm consisting of one or two heavy steel bars. The knee which supports the table and saddle units is moun­ted on the face of the column and can be moved up and down by me­ans of an elevating screw for adjusting workpieces with respect to cutters.

4. Vertical spindle machines are similar to plain milling ma­chines, but their spindle is positioned vertically.

5. Universal milling machines are also similar to plain mil­ling machines but the saddle is mounted on and swivels on clamp bed which slides on the knee: thus permitting the saddle to swing at an angle, and permitting table motion at other angles than 90° to the spindle axis.

6. Cutting speeds on the milling machine depend upon the na­ture of the work, the type of cutter, the condition of the machine and upon the experience and ability of the machine operator. Feed rates in milling are expressed in two ways: in, per min, or thousandth of an inch per revolution of the spindle.

 

III. Language.

Ex.6. Match word and word combination in column A with those in column B:

 

A B

1. зрушувати 1. remove

2. виступ 2.cutter

3. брусок 3.withstand

4. подання 4.deliver

5. полозка 5.valve

6. зміцнювати 6.supply

7. видаляти 7.shift

8. клапан 8.knee

9. фреза 9.secure

10. витримати 10.nose

11. постачати 11.bar

12. коліно 12.saddle

 

Ex.7. Fill in the blanks using the following words:

a) work; b) power feed; c) contains; d) knee; e) swivels; f) hardened

1. The saddle in universal milling machine is mounted on and _______ on a clamp bed.

2. The spindle is _______ ground, hollow shaft spaced horizontally from the front to the back of the column.

3. The ______ is mounted on the face of the column and can be moved up and down by means of elevating screw.

4. Milling is the process of removing material from _______ with multitoothed rotating cutter.

5. The base hollow inside, ________ a coolant tank with cutting fluid.

6. In the laver part of the column there is a motor for drilling the spindle and the change gears of _______.

 

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

1. The base, hollow inside, contains a coolant tank with cutting fluid that is

a) sufficiently heavy to withstand the weight of the machine;

b) connected directly to the coolant tank;

c) delivered through piping by means of a pump to the cutters

2. The centrifugal type pump is mounted

a) on the face of the column;

b) on the pad located at the side of the base;

c) on a solid wooden floor

3. The cutting fluid flow can be regulated by means of

a) valves connected to the outlet nozzles;

b) a motor-operated pump;

c) gears, shafts and bearings throughout the column.

4. In the lower part of the column there is

a) the knee which supports the table;

b) the charge gears for the power feed;

c) a motor for driving the spindle

5. In the upper part of the column there is

a) a set of change gears for driving the spindle at a proper speed;

b) various trains for providing the necessary cutting speeds

6. An overarm, consisting of one or two heavy steel bars is

a) attached to the spindle nose;

b) carried on an arbor;

c) secured to the top of the column.

Ex.9. Put questions to get the following answers:

1. Milling machines are used for milling operations.

2. Column and knee-type, milling machines are made in three styles: horizontal plain, vertical and universal spindle milling machines.

3. The centrifugal type pump is mounted on the pad located at the side of the base.

4. A constant supply of clear oil is pumped to the column and feed gearbox.

5. The horizontal plain milling machine has a horizontal spindle rotating in anti-friction bearings in the column.

6. Feed rates in milling are expressed in two ways: in, per min, or thousandth of an inch per revolution of the spindle.

 

IV. Comprehension.

Ex.10. Agree or disagree with the following statements:

1. The base, hollow inside, contains a heating tank with cutting fluid.

2. The outlet nozzles can be swivelled for distributing a low pressure volume of cutting fluid to all diameter and types of cutters.

3. A set of change gears for driving the spindle at a proper speed is housed in the lower part of the column.

4. The change gears are shifted automatically without an operator.

5. An elevating screw is used for adjusting workpieces with respect to cutters.

6. Vertical spindle machines are opposite to plain milling machines, but their spindle is positioned horizontally.

7. Universal milling machines are similar to plain milling machines but the saddle is mounted on and swivels on a clamp bed.

 

Ex.11. Answer the questions:

1. What is milling?

2. What are the main types of milling machines?

3. What does the base of the plain milling machine serve for?

4. By what means can the cutting fluid flow be regulated?

5. What is located in the lower part of the column?

6. What is secured to the top of the column?

7. Where is the knee mounted?

8. By what means can the knee be moved up and down?

9. What do cutting speeds on the milling machine depend upon?

Ex.12. Fill in the tables

 

Milling machines

a)

classes

column and knee machine

 

 

 

 

b)

 

V. Oral practice.