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материал по английскому языку

Слова и выражения к тексту:

Pliers – зд. кусачки

bench shears - верстачный ножницы

alligator shears – механические ножницы

ножовка - hack saw

pipe cutter - труборе́з

carbon steel - углеродистая сталь

cutting jaw - резак

Lateral surfaces – торцы

pitch of the blade – шаг полотна ножовки

reciprocating motion  - возвратно-поступательное движение

Изучите текст:

 METAL-CUTTING AND LOCKSMITH'S CUTTING TOOLS

Cutting is used for separating some part from a piece of metal as well as to cut angles, grooves and pipes. Depending upon the shape and size of workpieces cutting is done by means of different cutting tools such as pliers, bench-shears, alligator shears, hack saws and pipe-cutters made of carbon steel.

Fig. 4. Pliers:

I - cutting jaw; 2 – handle

Pliers, or wire-cutters (Fig. 4) are used for cutting thin wire. Pliers consist of two cutting jaws and two handles. A piece of wire is placed between the cutting jaws and the wire is cut by exerting pressure on the handles of the pliers. Bench shears are made of steel. Lateral surfaces of shear blades are hardened, sharpened and ground.

Bench-shears (Fig. 5) are provided with two handles one of which is at a right angle to the other and fixed on a bench.  The material is cut by pressing on one of the handles.

Fig. 5.

Bench-Shears: 1 - shear blade; 2 – handle

Fig.6. Hack Saw:

1 - frame; 2- toothed blade

A hack saw (Fig. 6) is used for cutting thick metal sheets, bars, round-shaped material, etc. The hack saw consists of a frame and a long toothed blade made of tool carbon steel. The teeth on the blade are hardened. The blades with different pitches have different applications, the pitch of the blade depending on the material to be sawed. The thinner the material to be handled, the finer must be the pitch of the blade used for sawing this material, and vice versa.

Fig. 7 shows alligator shears which is a heavy duty machine used for cutting materials of large sections such as pipes, beams, auto frames, axles and different types of industrial scrap. The alligator shears consist of cast iron bed I and bedplate 2. Arm 3 is mounted on the bedplate. Cutting blade 4 is fixed within the arm.

Electromotor 5 imparts reciprocating motion to the arm and the blade. The workpiece to be cut is clamped in machine vice 6.

Fig.7 . Alligator Shears:

1 - bed; 2 - bedplate; 3 - arm; 4 - cutting blade;

5 - electromotor; 6 - machine vice

Fig. 8. Pipe-Cutter:

1 - body; 2 - rollers; 3 - roller; 4 – handle

Special pipe-cutters (Fig. 8) serve for cutting pipes. The pipe-cutter consists of body 1, handle 4, and three steel cutting rollers. Two rollers 2 installed on the fixed axles of the body and roller 8 installed on the axle of the handle may revolve and cut a pipe fixed in a special pipe fixture. For this purpose the pipe-cutter is turned round the pipe to be cut, pressing the cutting rollers against its surface.

Exercises

1/. Вставьте пропущенные слова.

l. The p... of a blade is the distance from the point of one t... to the point of the next t.... 2. This pitch is expressed by the number of t... per one inch of the b... length. 3. The hand hacksaw blade is a thin blade with teeth formed on one е.... 4. The flexible h... s... blade is used for s...ing tin, copper, aluminium and other soft metals. 5. Cutting is done by means of different c... t.... 6. For cutting wire such cutting t... as p... are used. 7. One handle of b...-s... is at a r... a... to the other.

2. Переведите предложения.

Example: Материал, который нужно разрезать, зажимается в тисках.

The metal to be cut is clamped in the vice.

1. Шаг полотна ножовки зависит от материала, который будет распиливаться. 2. Различные виды стали, которые используются для полотна ножовок, изготовляются на нашем заводе. 3. Полотно ножовки, которое надо использовать для распиливания этих тонких листов, должно иметь 32 зуба на один дюйм. 4. Труба, которую надо разрезать труборезом, будет закреплена в специальном приспособлении, 5. При вращении трубореза вокруг изделия, которое надо разрезать, создается режущее усилие.

3.Ответьте на вопросы

l. What are pliers used for? 2. What do the pliers consist of? 3. What is the function of pliers, jaws and handles? 4. What material are bench-shears made of? 5. What are the bench-shears provided with? 6. What purposes are alligator shears used for? 7. What principal parts do the alligator shears consist of? 8. What part of the alligator shears is the arm mounted on? 9. Where is the cutting blade of the alligator shears fixed? 10. What motion does the electromotor impart to the arm and the blade? 11. What purpose are pipe-cutteres used for? 12. What parts coes a pipe-cutter consist of? 13. How is the cutting performed? 14. Where is the pipe fixed for cutting?