Mitte Realty

Otis joined the cable to the platform lift through a flat spring similar to spring, and on the sides of connecting the lift rack rails. Even under the weight of the empty platform spring is straightened and easy passage between the rails. If, God forbid, the rope tore, spring, arches, stuck at their ends in the teeth of the rails and thus prevented the fall in freight elevator. Otis christened its lifting platforms 'safe elevators' and opened a small factory to produce them, which still remains the leader in this field. In 1854, Otis had an ambitious PR-campaign to promote produced by him freight elevators. In New York in the exhibition hall with a very tall dome moved lifting platform between 2 pillars height of 12 meters.

At the top of the building was a man with a large sword in his hand, and on the platform in pile yaschikovkorobok and drums adorned himself an inventor in a tailcoat and top hat. Steam engine elevator to the very dome, then an assistant at the signal Otis dramatically pererubal rope with a sword. Elevator fell down, but after one or two Automatic meter with a wild screech fire and prevented the fall. Satisfied Otis shot cylinder and bowed enthusiastic observers of this action. In 1857, a 5-story building on Broadway, installed the first passenger elevator, which released the company Otis. Elevator holds up to 5 people and and fell at a rate of 20 cm / sec. Otis, unfortunately, not fully realized the genius of his invention, because when skyscrapers began to appear, he had already died. In the first skyscraper was used hydraulic elevator without the rope, which was manufactured in Paris in 1867 and slightly later is installed on the Eiffel Tower.

In a long cylinder was located walking piston that pushes cabin top under the pressure of the liquid. But such elevators for residential buildings could be constructed in a building not more than 20 floors, though, and went to twenty times faster than passenger lifts of Otis. Later upgraded hydraulics – cylinder was placed horizontally, and the rope that lifted the cab, stretched by the piston through a system of blocks. For the first time an electric passenger elevator was made in 1880 by German kompanieyfabrikoy 'Siemens and Halske ', which for eleven seconds to a height of twenty-two meters. Since the problem of lifting height is no longer restrained growth in the number of floors of skyscrapers. The highest skyscraper 'Sears Tower' in Chicago (America) equipped with 106 passenger elevators. 16 of them – two-story: take and land passengers on two floors. For visitors to the observation deck on the roof there are two express elevators that rise to a height of 412 meters a little more than a minute.