An elevator is simply a device that increases or decreases a person’s potential energy without them needing to supply that energy themselves: the elevator gives you potential energy when you’re going up and it takes potential energy from you when you’re coming down.

How it works:

1-The elevator compartment is raised and lowered by a hoist and pulley system and a moving counterweight .The
elevator is moves smoothly between vertical guide bars: it doesn’t just dangle stupidly from the rope.

2-The cable that does all the lifting wraps around several pulleys and the main winding drum. Don’t forget this
elevator was invented before anyone was really using electricity: it was raised and lowered by hand.

3-At the top of the elevator car, there’s a simple mechanism made up of spring-loaded arms and pivots . If the main cable breaks, the springs push out two sturdy bars called “pawls” so they lock into vertical racks of upward-
pointing teeth on either side. This ratchet-like device clamps the elevator safely in place.

4-Most elevators have an entirely separate speed-regulating system called a governor, which is a heavy flywheel
with massive mechanical arms built inside it. Normally the arms are held inside the flywheel by hefty springs,but if the lift moves too fast, they fly outward, pushing a lever mechanism that trips one or more braking systems. First, they might cut power to the lift motor. If that fails and the lift continues to accelerate, the arms will fly out even further and trip a second mechanism, applying the brakes. Some governors are entirely mechanical; others are electromagnetic, still others use a mixture of mechanical and electronic components.