Elevators are wondrous things. Without them, climbing up to the top of the Empire State Building or the Eiffel Tower would be almost impossible. Building them would have been very difficult in the first place. They would have been invented way earlier had people just figured out how to make them stop at a certain place at a given time. The truth is that the elevator is a very simple machine. It is just a hoist. A hoist is any device that is used for lifting or lowering a load using a drum or lift-wheel and a rope or chain. A lifting hook attaches the load to the hoist. Thanks to Elisha Otis, we can now climb up to the rooftop of a monstrous skyscraper without too much effort.
History of Hoist Brakes
Actually, Elisha Otis didn’t invent the elevator. He invented its brakes. Imagine riding an elevator on the 55th floor without its brakes and you’ll surely go all the way down to the ground floor in no time. Pray you’d still be alive when you come out of it. That’s what brakes do. Hoist brakes ensure people’s safety by slowing and stopping the device like an elevator carefully, precisely, and efficiently.
Hoist Brake Functionality
So how do hoist brakes work? In elevators, hoist brakes are designed to guarantee safety during normal use. The most common types are made up of selenoid assembly, brake shoes with linings, and a compressive spring assembly. The spring forces the shoes to grip the drum and cause a braking torque when the selenoid is not energized. For the break release, the magnet exerts a horizontal force directly on an operating arm. It can also be done through the linkage system. The break is then pulled away from the shaft and the elevator gets back to its normal velocity.
As an additional safety measures, elevators also have electromagnetic brakes. These brakes engage when the car comes to a stop. The electromagnets keep the brakes in the open position. These brakes automatically clamp shut when the elevator loses power.
Hoist brakes may not be the most well-known type of breaks in the world, but we benefit greatly from them. Elevators are just one of the many inventions made possible with hoist brakes.