United States Otis invented the safety elevator
It has been 158 years since the elevator entered people's lives. In 1854, at the World's Fair held in the Crystal Palace in New York, American Elisha Graves Otis presented his invention to the world for the first time. He stood on the elevator platform filled with cargo and ordered his assistant to lift the platform to a height where the audience could see. Then he sent a signal and ordered the assistant to cut the lifting cable of the elevator with a sharp ax.
Surprisingly, the elevator did not crash, but remained firmly fixed in mid-air - the elevator safety device invented by Mr. Otis came into play.
"Everything is safe, gentlemen." Mr. Otis, standing on the elevator platform, waved to the people watching around him. No one would have thought that this was the first safety elevator in human history.
Elisha Graves Otis shows people the safety elevator he invented
Human beings have a long history of using lifting tools to transport goods and people. As early as 2600 BC, the Egyptians used the most primitive lifting system when building the pyramids. The basic principle of this system remains unchanged today: when a counterweight descends, the load platform rises. Early lifting tools were basically powered by human power.
1 In 203, a donkey-powered crane was installed in a monastery on the coast of France, ending the history of using human power to transport heavy objects. After the British scientist Watt invented the steam engine , crane devices began to use steam as power.
followed closely, William Thomson developed a hydraulically driven elevator, and the hydraulic medium was water. On the basis of these elevators, generations of innovative engineers continue to improve elevator technology. However, a key safety issue has never been resolved, that is, once the lift cable breaks, the load platform will definitely crash.
Otis designed a brake: a truck spring and a brake rod are installed on the top of the elevator platform and connected to the guide rails on both sides of the elevator shaft. The lifting rope is connected to the truck spring. This is only for lifting. The weight of the platform is enough to pull up the spring and avoid contact with the brake lever. If the rope breaks, the truck spring will weaken the tension, and the two ends will immediately engage with the brake lever, which can firmly fix the platform in place to prevent it from falling further.
Principle of the world's first safety elevator
"Safe elevator" was invented successfully! For a time, Otis became the center of attention.
Mr. Otis's invention completely rewritten the history of human use of lifting tools. Since then, taking an elevator is no longer a "game for the brave" and elevators have been widely used around the world.
In December 1889, the American Otis Elevator Company manufactured a veritable elevator. It used the DC motor as power, and drove the rope wrapped around the drum through a worm gear reducer to suspend and lift the car. In 1892, the American Otis Company began to use push-button control devices to replace the traditional control method of pulling ropes in the car, setting a precedent for the modernization of control methods.
Life goes on, technology is developing, and elevators are also improving. Over the past 150 years, the materials of elevators have changed from black and white to colorful, and the styles have changed from straight to slanted. In terms of operation and control, they have made new progress step by step - handle switch operation, button control, signal control, collective control, human-machine dialogue, etc. , multiple elevators have also appeared in parallel control and intelligent group control; double-deck car elevators have shown the advantages of saving shaft space and improving transportation capacity; the emergence of variable-speed automatic sidewalk escalators has greatly saved pedestrians' time; different shapes - fan-shaped , triangular, semi-rhombus, semi-circular and full-circle sightseeing elevator make the sight of passengers in them no longer closed.
Today, the world's leading elevator companies, represented by the American Otis Company, continue to develop new elevator products and continue to improve repair and maintenance service systems. FM door control, intelligent remote monitoring, host energy saving, control cabinet low noise and durability, composite steel belt environmental protection - new elevators that incorporate the latest scientific research achievements of mankind in the fields of machinery, electronics, optics and other fields are coming out one after another, Leng Bingbing The buildings therefore radiate the brilliance of humanity, and people's lives become better.
