Elijah Otis: Elevators

Elevators have distinguished themselves as a component of our modern world. They guide us to our destinations faster and help us innovate our technologies to higher levels to keep up with our fast-paced world. Based on simple machinery, its minimalism proves to be the heart beat of our improving industrial communities. Although Elijah Otis improved the invention of the elevator in 1850, the composition, structure, and limitations are still improving today. Though there are many types of elevators, the most common type is the roped elevator. This type of system consists of many parts to hold the circuit together, but the main components are the electric motor, guide rails, counterweight, sheave, and the control system. With all of these parts, an elevator is considered to be a machine because of its pulleys and action of changing direction or magnitude of a force. The ropes are attached to the elevator car, and looped around a sheave(3). A sheave is just a pulley with a grooves around the circumference. The sheave grips the hoist ropes, so when you rotate the sheave, the ropes move too. The sheave is connected to an electric motor(2). When the motor turns one way, the sheave raises the elevator; when the motor turns the other way, the sheave lowers the elevator.Typically, the sheave, the motor and the control system(1) are all housed in a machine room above the elevator shaft.The ropes that lift the car are also connected to a counterweight (4), which hangs on the other side of the sheave. The counterweight weighs about the same as the car filled to 40-percent capacity. In other words, when the car is 40 percent full (an average amount), the counterweight and the car are perfectly balanced. Both the elevator car and the counterweight ride on guide rails(5) along the sides of the elevator shaft. The rails keep the car and counterweight from swaying back and forth, and they also work with the safety system to stop the car in an emergency. These five components not

Cited: Joel, S. (2012, October 12). How Elevators Work . Retrieved from http://www.madehow.com/Volume-2/Elevator.html Tom , H. (2012, November 24). Elevators . Retrieved from http://science.howstuffworks.com/transport/engines-equipment/elevator.htm