MACHINES (TO RAISE AND LOWER)

The tall buildings have elevating machines to take people to the different floors. During construction, materials must also reach all floors. The best lifting machines are cranes, elevators and escalators, but the simplest is the pulley. Elevators are also used in mines to transport miners and materials to and from the surface.

A tower crane lifts heavy materials, such as cement blocks and steel beams, in one construction. A very powerful rotary winch, called a winch, drives the steel cable that lifts the load. As the building gains in height, sections are added to the crane. A tower crane is armed from below. New sections are added to it. A counterweight balances the weight of the davit and the load, THE electric dock inside the cabin raises and lowers the hook. Another motor moves the magazine horizontally. The hook attached to the loader of the crane raises and lowers the materials by means of pulleys.

An elevator or elevator goes up and down inside the building by means of a motor and a pulley. The cable that holds the elevator goes through a pulley and extends to a counterweight that balances the weight of the elevator. Thus the movement is simplified. An elevator is comprised of:

An escalator is a moving staircase. The steps in sections circulate between a driving wheel in the upper part and a return wheel in the lower part. An electric motor starts the driving wheel. The handrail moves at the same speed as the steps.

A simple pulley consists of a wheel and a rope above it. When pulling down one end of the rope, the weight of the other end is lifted. A double pulley has two wheels; You can lift twice the load with the same effort.