Essay On Hoists

Elevators started out as hoists. Hoists date back to thousands of years ago; pulley and winch systems were used anciently to raise water and building materials as shown in Figure 1.1. It is believed that hoists have played a very important role in the construction of the Great Pyriamds built by ancient Egyptians.

However, the first document evidence of their use is from Greece. Back in 236 B.C, Greek mathematician, physicist and inventor Archimedes used a rope-and-pulley mechanism and invented a hoist device; the hoist rope was wrapped around a capstan; a person would have to pull a lever in order to rotate the drum. It is thought that three of this device were first introduced in the Palace of the Roman Emperor Nero. Human-powered and human-counterweight hoists were used in ancient Rome to draw water from wells. It is also believed that Emperor Napoleon

He installed a safety device called the safety brake (today called safety gear) into the elevator. Otis’s safety brake consisted of a ratchet and saw tooth iron bars; in case of rope failure, a spring would pull the ratchet and engage it into the saw tooth bars, bringing the elevator car to a secure stop. In 1854, Otis publically demonstrated his invention at the Crystal Palace in New York. Otis cut the elevator rope by himself and watched the safety brake work perfectly. This day marked a remarkable development in the history of elevators. Meanwhile, on the other side of the Atlantic, in England, Frost and Stutt successfully developed a counterbalance-type, traction-method elevator called the “Teagle”, in 1853. Frost and Stutt’s Teagle and Otis’ safety brake became fundamental elevator safety features, thus ushering in the age of the safe elevator. Architects were able to let their imaginations soar skyward, and city skylines would never be the