How does an Elevator work?

History and the Otis Safety Invention00:00:01

Elevators enabled modern urban development and tall skyscrapers. While lifting devices existed in antiquity, it was Elisha Otis in the 1850s who invented the critical safety brake mechanism—using a leaf spring and pivot arms—that allowed elevators to safely transport people.

Hydraulic vs. Traction Elevators00:03:38

There are two primary elevator systems: hydraulic elevators, which use a piston and oil pressure for low-rise buildings, and traction elevators, which use electric motors, cables, and counterweights to serve tall skyscrapers efficiently.

Traction Elevator Mechanics00:04:41

Traction elevators operate using a motor, a sheave pulley, and a counterweight that balances the cab to reduce strain on the motor. Advanced versions, known as Machine Room-Less (MRL) elevators, house all components directly within the elevator shaft.

Emergency Safety Systems00:06:25

Elevators feature robust safety redundancy, including multiple high-strength cables and an overspeed governor. If the cab descends too quickly, the governor activates emergency clamps that grip the guide rails, halting the elevator immediately.

Door Operation and Interlocks00:08:29

Elevators utilize a two-part door system consisting of hoistway doors and cab doors. A clutch mechanism on the cab interacts with pickup rollers on the floor doors, ensuring that doors only open when the cab is safely aligned and stopped at a floor.