1852, Mr Otis, a mechanical engineer in new york, was asked by his employer (the boss of bedstead manufacturing company) to build a freight elevator to transport the company's products. In order to solve the safety problem of elevator, Otis invented a device. He fixed the sawtooth iron bar on the guide rail, put a spring leaf on the upper part of the car and connected it with the brake claw by mechanical linkage. The traction rope is fixed in the center of the spring leaf. When the traction rope breaks, the spring leaves return to their original state, forcing the mechanical linkage to act, and then the brake claw extends into the serrated iron bar to prevent the elevator from falling. In this way, the world's first "safety elevator" was invented.

Although Otis is known as the father of elevators, in fact, Otis himself has never built a truly modern elevator, because in his time, the common power of machines was steam generated by coal burning. It was not until1889+February that Otis Elevator Company installed the first real elevator in Dimarest Building in new york. It uses DC motor as power, and the rope wound on the drum is driven by turbine reducer to hang and lift the car. This ancient elevator can only walk about 10 meters per minute. 1900, the elevator driven by AC motor came out. 1902, Schindler, Switzerland, successfully developed the world's first push-button automatic elevator, which adopted fully automatic control mode, and improved the conveying capacity and safety of the elevator.