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Elevator

An elevator or lift is a type of vertical transportation that moves people or goods between floors of a building, vessel, or other structure. Elevators are generally powered by electric motors that either drive traction cables and counterweight systems like a hoist, or pump hydraulic fluid to raise a cylindrical piston like a jack.

The earliest known reference to an elevator is in the works of the Roman architect Vitruvius, who reported that Archimedes (c. 287 BC – c. 212 BC) built his first elevator probably in 236 BC. In 1000, the Book of Secrets by al-Muradi in Islamic Spain described the use of an elevator-like lifting device, in order to raise a large battering ram to destroy a fortress.

Ancient and medieval elevators used drive systems based on hoists or winders. The invention of a system based on the screw drive was perhaps the most important step in elevator technology since ancient times, leading to the creation of modern passenger elevators. The first screw drive elevator was built by Ivan Kulibin and installed in Winter Palace in 1793.

Starting in the coal mines, by the mid-19th century elevators were operated with steam power and were used for moving goods in bulk in mines and factories. Early, crude steam-driven elevators were refined in the ensuing decade; – in 1835 an innovative elevator called the "Teagle" was developed by the company Frost and Stutt in England. The elevator was belt-driven and used a counterweight for extra power.

In 1845, the Neapolitan architect Gaetano Genovese installed in the Royal Palace of Caserta the "Flying Chair", an elevator ahead of its time, covered with chestnut wood outside and with maple wood inside. It included a light, two benches and a hand operated signal, and could be activated from the outside, without any effort on the part of the occupants. Traction was controlled by a motor mechanic utilizing a system of toothed wheels. A safety system was designed to take effect if the cords broke. It consisted of a beam pushed outwards by a steel spring.

In 1852, Elisha Otis introduced the safety elevator, which prevented the fall of the cab if the cable broke. The design of the Otis safety elevator is somewhat similar to one type still used today. A governor device engages knurled roller(s), locking the elevator to its guides should the elevator descend at excessive speed. He demonstrated it at the New York exposition in the Crystal Palace in a dramatic, death-defying presentation in 1854.

Schuyler Wheeler invented the electric elevator, patenting it in 1883. The first electric elevator was built by Werner von Siemens in 1880 in Germany. The safety and speed of electric elevators were significantly enhanced by Frank Sprague who added floor control, automatic elevators, acceleration control of cars, and safeties.

In 1874, J.W. Meaker patented a method which permitted elevator doors to open and close safely. In 1887, American Inventor Alexander Miles of Duluth, Minnesota patented an elevator with automatic doors that would close off the elevator shaft. By 1900, completely automated elevators were available, but passengers were reluctant to use them. A 1945 elevator operator strike in New York City, and adoption of an emergency stop button, emergency telephone, and a soothing explanatory automated voice aided adoption.

Periodical inspection

Most countries enforce periodic elevator inspections as a legal requirement. The time intervals between those periods differ from country to country, however, the basic principle is the same: safer vertical transportation for everyone.

We, in RoyalCert, carry out our part of the public responsibility and conduct periodical elevator inspections to increase the safety of the devices we use every day.