How does the elevator work?

Elevators have been around for over 150 years. 

In the 1800s, new iron and steel production processes revolutionized the world of construction. With sturdy metal beams as their building blocks, architects and engineers could erect monumental skyscrapers hundreds of feet in the air.

But these towers would have been basically unusable if it weren't for another technological innovation that came along around the same time. Modern elevators are the crucial element that makes it practical to live and work dozens of stories above ground. High-rise cities like New York absolutely depend on elevators. Even in smaller multi-story buildings, elevators are essential for making offices and apartments accessible to handicapped people.

Most elevators work just like a pulley. A very strong metal rope is joined to the top of the elevator car and goes up through a “sheave” in the engine room above the elevator. The sheave is like a pulley wheel with grooves in it to hold the rope tightly. On the other side of the rope is a weight, which is about as heavy as the elevator car when it is half full. This balances the car, so that not too much energy is needed to move it.

Both the weight and the elevator car are held in place by guide rails at the sides of the elevator shaft (the tunnel the elevator is in). A motor can turn the wheel in either direction so that the elevator either goes up or down (with the weight doing the opposite). When you push the button inside the elevator, you activate the motor. When the motor stops, the grooves in the pulley wheel keep the rope in place so the elevator stops moving.

When you step into an elevator and close the door, you had passed through two doors and are now standing in a box (or the elevator car) inside a vertical passageway (called the lift shaft). One door is in the walls of the floor that you got off, and the other door is part of the car itself.

Inside the shaft are hoisting cables attached to the top of the car. The cables run over a sheave (pulley) connected to an electric motor at the top of the shaft. The other end of the cables is connected to a heavy steel weight called a counterweight. When the car goes up, the counterweight goes down; when the car goes down, the counterweight goes up.

How the counterweight reduces to a minimum the power needed to operate the elevator ...

The weight of counterweight = Weight of the car + (about) ½ of its maximum passenger load

So when the elevator operates, it needs power only to lift the weight of the extra passengers in the car; the rest of the weight is balanced by the counterweight.

 

The basic main parts of an elevator.

Heavy balance:

You must have noticed this. As long as the elevator is on the top floor, you can see it on the ground floor. When the elevator starts to fall, the balance begins to move upward and vice versa.

But why do we need it? Imagine that the elevator must be on the floor of the tenth floor, which will require 1000 kj of energy. What these smart-aleck people do-they've added weight to the other end of the cable. What's happening now is that the motor above needs less energy to lift you up, because our friend, Mr. Balance, is already helping us pull us up. This means that instead of 1000 kj, this time you need less energy, such as 500 kj, which consumes less power.

Here you go. A counterweight makes the motor easier to raise and lower the car just like sitting on a saw, making it easier to lift people's weight than to lift them in your arm. In addition, a heavy lift car is difficult to pull up, but will come down to the ground. Thanks to counterweight, it makes it easier to control cars.

The weight of the counterweight is almost half that of a loaded car.

Door:

Auto doors are essential and are very convenient for people with disabilities. A typical automatic door system consists of a motor connected to the arm, which is connected to a long metal arm connected to the door.

Then the door can slide back on the metal track. When the motor turns the wheel, it turns the first arm, which causes also the rotation of the second long metal arm to close or open the door. The door is made of two panels, closed when the door is open when they are closed when extended.

You can access this link to see the animation.

In addition, many elevators have a motion or ultrasonic sensor, and if someone is between them, keep the door closed.

Electronic Systems:

Basically, what they are talking about is the "elevator algorithm " which is sent to the elevator's computer system-Stop the button on the floor to say, alarm etc.

Security:

Making cables with stranded wires does not guarantee 100% safety. So Otis Elevator (Otis-designed it for the man) has a ratchet system as a backup. Each car runs to the top of the two vertical rails. If the cable is broken, a spring-loaded mechanism with the hook emerges in the metal teeth. So now you're stuck somewhere between the floors, but you're safe. These mechanisms are used on Otis elevators, and few people have it today.