Elevator

An elevator is also called a lift. It is a car that moves in a vertical shaft to carry passengers or freight between the levels of a building. Modern elevators are usually controlled by electric motors. The important part of its construction is a counterweight. Electric motors control an equilibrium state through a system of cables and pulleys connected with a car and counterweight. The elevator has

been playing an important role since we have built higher buildings. The practice of lifting loads by mechanical means during building operations goes back to Roman times. The main principle which is balance between counterweights and cars stays the same. Differences are only in the way how to keep it. The introduction of electricity led to push-button controls and the power applied to the pulley at the top of the shaft. Modern elevators are built in a variety of types which have different purposes.