VI. Find the equivalents to the following word combinations:

1. A load lifting appliance a) таль с ручным приводом

2. A lower lying load b) электрические фрикционные лебедки

3. Ratchet pawl released c) грузоподъемное приспособление

4. Hand-operated winches d) низко-лежащий груз

5. Electric friction type winches e) разъединенная собачка храповика

6. Suspension-type small-size f) ручные лебедки

mechanism

7. Hand-operated hoist g) механизм небольшого размера

подвесного типа

VII. Translate into Russian paying attention to the Participle and the Gerund.

1. Appliance for raising a load to a small height.

2. Hydraulic jacks capable of handling up to 500 tons of weight.

3. Reciprocating pump actuated by a lever.

4. Structures weighing thousands of tons.

5. Several jacks operated by one electrically driven pump.

6. Rack-and-pinion jacks employed in our country.

7. A channel connecting the cylinder with the chamber.

VIII. Read the following text.

HANDLING EQUIPMENT

A jack is the simplest load lifting appliance for raising a load to a small height. There are mechanical (screw and rack-and-pinion) and hydraulic jacks (Fig.1).

When lever 1 of rack-and-pinion jack (Fig.1a) is turned, motion is transmitted through gear drive 2 to rack 4 which raises the load on its support 3 and 5. A rack-and-pinion jack has a higher efficiency and its support 5 can be placed under a lower lying load than in a screw jack. On the other hand, it is more dangerous in operation since it has no brakes and the load is lowered with the ratchet pawl released (Fig.1b).

Hydraulic jacks capable of handling up to 500 tons of weight are employed to erect heavy equipment and structures to a height of 0.15-0.3 meter.

Ram 7 (Fig.1b) moves in a cylinder. Piston 6 rises when fluid is forced into the cylinder from chamber 8 by reciprocating pump 9 actuated by a lever. A channel connecting the cylinder with the chamber and stopped by valve 10 is used to lower the piston.

To raise structures weighing thousands of tons several jacks operated by one electrically driven pump are jointed together.

Rack-and-pinion jacks employed in our country can handle from 0.5 to 10 tons, screw jacks from 1 to 20 tons and hydraulic jacks from 3 to 500 tons.

Winches are widely used in the construction industry. There are hand-operated winches and electric friction-type winches. Hand-operated winches (Fig. 2) are used for auxiliary construction purposes. They consist of drum (1), gear drives (3) and disk brakes (2). Winches of this type develop a pull of up to 10 tons. It is interesting to note that in construction electric friction-type winches are used as a rule. The winch is driven by an electric motor through a V-belt drive and a pair of gear wheels. The rope drum is fitted freely on the shaft. Winches can handle from 0.25 to 15 tons.

A hoist is a simple suspension-type small-size mechanism. It is used mainly for assembling machines. There are hand-operated and electric hoists. A hand-operated hoist is shown in Fig. 3. (1- automatic brake, 2 – worm couple, 3 - sprocket,4 - chain wheel, 5 - endless chain, 6 - roller chain).

Hand-operated hoists can handle from 0.25 to 10 tons of load while electric hoists handle from 0.125 to 10 tons.