Wikijunior:How Things Work/Elevator

Apart from in the United States, an elevator is known as a lift. The term "elevator" is actually the brand name of a lift by a company within the United States. The company was so successful and installed them in so many places, that people started to refer to lifts as elevators. This in turn caused the company to lose its "Elevator" trademark and it became the common name in the United States for a lift.

A lift is designed to transport vertically in a controlled manner. The most common use of a lift is to move people between floors in buildings all over the world. They are also used in mines and manufacturing processes to move material and personnel.

A lift is made up of four major components: The lift cab or platform, the shaft or hoist-way, the drive system and the counterweight.

The cab is moved vertically inside the shaft using either a hydraulic piston or a pulley system, normally the weight of the cab is balanced by counterweights so that the drive system uses minimal energy.

Who invented it?
Elisha Graves Otis (August 3, 1811-April 8, 1861) invented a safe way of braking a hoisting machine, making it safe for people to use. This enabled the development of the passenger lift, the pulley elevator.

How does it get power?
Usually lifts are powered by electricity drawn from the power grid. However, they can be powered in other ways including by draft animals. Also, since you might want to use a lift in a power cut, there can often be a big battery used to power a lift if the power grid is broken.

How does it work?
An elevator is really just a cab (or box) attached to a pulley or hydraulic system, which you will read about later, with some counterweights thrown in to make it easier to lift. When you push a button, it tells the pulley how much to turn, and the elevator moves to where you want it to.

How dangerous is it?
Elevators can be dangerous. For instance, if the pulley or hydraulic system moves the wrong distance, people can get stuck inside the elevator, and they have to call the firemen. Actually being stuck inside an elevator which has stopped past a floor isn't dangerous. Trying to get out yourself prior to having the licensed elevating mechanic open the door for you is. The doors can't close on you these days either, there is either a mechanical arm which travels with the door that when hit will cause the door operator to re-open. Or there is what is called a door detector placed on the car door, which uses light rays, and should the light rays be broken the door re-opens as well.

Some people are scared that if the power goes out an elevator will fall. This is not true, as an elevator has a brake that will stop the elevator from falling far.

What does it do?
The lift transports people to different floors of a building by moving upwards and downwards.

How does it vary?
Elevators usually carry people, but in large buildings there are separate goods elevators to transport things between floors. In Israel, Argentina and other countries with large Jewish populations there are Sabbath elevators which operate on the Jewish Sabbath. They automatically stop at every floor without any buttons being pressed which allows Jews to use the elevator on the day when they're not allowed to do physical work like pressing buttons.

In large skyscrapers there are sometimes double-decker elevators. The lower part will call at odd-numbered floors (1,3,5 etc.) and the upper part will call at even-numbered floors (ground, 2, 4, etc.)

How has it changed the world?
The elevator has changed the world dramatically. Without elevators you would not have mid/high rise buildings, since it would take too long to access the top floors on foot. The New York City skyline would probably be a series of five story buildings.

Lifts also mean that people with physical disabilities are able to access the upper floors of building in a wheelchair. Wheels don't work on stairs!

What idea(s) and/or inventions had to be developed before it could be created?
Before the elevator could be invented, the simple lifting machine had to be. The elevator is simply a safe lifting machine.

Fastest elevators in the world
1. Taipei 101 (60.6 km/h)

2. Yokohama Landmark Tower (45.0 km/h)