The elevator is a permanent transport equipment that serves a number of specific floors in the building and its car runs on at least two rigid tracks perpendicular to the horizontal plane or with an inclination Angle of less than 15° from the plumb line. There are also stepped, stepping plate mounted on the tracks to run continuously, commonly known as escalator or moving sidewalk. Fixed lifting equipment for assigned floors. A vertical lift has a car that runs between at least two rows of rigid guides that are vertical or have an Angle of less than 15°. The size and structure of the car facilitate passenger access or loading and unloading. It is customary to use elevators as a general term for vertical transportation in buildings, regardless of their driving mode. According to the speed can be divided into low speed elevator (4 m/s below), fast elevator 4 ~ 12 m/s) and high speed elevator (12 m/s above). Hydraulic elevators began to appear in the mid-19th century and are still used in low-rise buildings today. In 1852, Otis of the United States developed a safety hoist for wire rope lifting. In the 1980s, the driving device has been further improved, such as the motor through worm drive winding drum, the use of balance weight. At the end of the 19th century, friction wheel drive was adopted to greatly increase the lift height of the elevator.
At the end of the 20th century elevators were powered by permanent magnet synchronous traction machines. It greatly reduces the space occupied by the machine room, and has the advantages of low energy consumption, energy saving and high efficiency, and fast improvement, which greatly boosts the development of the real estate to the direction of super high-rise.
Some elevators have giant buttons at the bottom that you can push with your foot to make it easier for people who don’t want to push by hand.
