I have posted about the Sedgwick elevator in the house. It is a rope pulled elevator. It seems that this can be confusing to people. Many picture a laborious ride in such an elevator like something out of ancient Egypt. You step into the elevator grab a rope and pull yourself to the second floor. Don’t let go. You will plummet to your death, elevator and all.
Actually it is an ingenious simple mechanism that allows the elevator to work using counter-weight balance and gear ratios to make the work easier. Modern elevators work in the same manner. There is not a winch with a rope pulling an elevator car up and unwinding to make it go down. Every elevator uses weights that balance with the elevator car. The motor is simply turning one direction to make the elevator car go up and the counter-weight go down. The opposite direction of the motor causes the weight to go up and the car to godown. That is why there are weight limits posted in every elevator. Too many people in the elevator car over powers the counter balance weight. This makes the motor struggle to raise the elevator car and accidents could occur.
The rope pulled in one direction rotates a 48″ diameter flywheel. There is a breaking system on the back of the flywheel that stops the movement when you stop pulling the rope. The flywheel is turning 4 different gears that ultimately turn the Drive wheel that moves the steel cables that are attached to the elevator car on one end and the 500 lb counter-weight on the other.
So that is how it works. I love the mechanics of it all. Simple engineering at its best.