Definition of the concept and components.
An elevator is a means of transportation that transports people and goods vertically from the bottom up and vice versa. The elevator is usually placed in multi-story buildings, to facilitate climbing to the upper floors without difficulty due to laws in some countries. It may be a legal requirement to have elevators in some large buildings, especially if other means are impractical.
The mechanism of moving the elevator has varied throughout history. From physical effort to steam engines, and from now to common electric motors. But the working principle remained the same, which is a room tightened by a rope that raises or lowers it, with special cases for elevators such as those in which the room is supplied with a motor.
Current elevators, especially electric ones, provide a button panel that allows the passenger to choose the level or floor he wants to reach.
We often find elevators installed inside empty columns that allow the elevator room (the cabin). This is done by moving vertically (up and down). And if the elevator room is a closed room with a door, it is sometimes made of glass sides that allow travelers to follow the outside atmosphere, whether it is the lobby of the building. As is the case in some hotels or markets or with a view outside the 25 years old building, especially in buildings with glass.
Elevators have become an unavoidable necessity, especially in high-rise buildings, and a special type has appeared, which is elevators for people with special needs and wheelchair users.
A freight elevator is a device primarily designed to transport heavy loads with or without people. In public places such as markets, cultural centers, factories, etc. And they are manufactured to suit the use and users.
For example, in France, according to the Federation of Independent Experts and Elevator Control Offices (Fédération des independents experts et bureau de control ascenders: Fierce), there were about 450,000 elevators in 2010. Half of this number is over 25 years old, and a quarter is over 40 years old.
For several centuries tall buildings (such as Greek monasteries) were semi-isolated places, inaccessible, except by primitive “without motor” lifts. The first appearance of elevator machines was in the mines in general. In the mines, there was a concept of supplying elevators with a steam engine, and that was in the early nineteenth century.
The first elevators that were provided to skyscrapers and designated for the public from the beginning of the nineteenth century to the twentieth century, allowed ascent only to the upper floors, while the descent remained limited to stairs only. Architects often allocate a place for elevators near the stairs. In many cases, the stairs were wrapped around a shaft intended for elevators in a spiral shape with a metal spacer for protection.
In the first third of the twentieth century, the elevators of large and grandiose hotels were decorated like the luxury trains of their time. The windows, doors of the room, and the cage bore gilded latticework in pure gold from the middle of the twentieth century and increasingly severe restrictions were placed on the urban law, by providing buildings with elevators, so the use of elevators became a common mechanism.
Engineering, dimensions and construction of elevators
Provides safe transportation for people daily The number of movements per person is estimated at one billion movements, two million installed monitoring devices to warn of any malfunction, and elevators are often connected to a remote control center. Users can use the phone in the room for the control center of the computer network stores some of the information it receives the device’s sensor for the elevator system, and the rest is stored locally in the electronic control device.
The local control center for elevators in skyscrapers is equipped to record all daily movements. This is to provide a lift to everyone who requests it and avoid delays that users feel. The mobile system allows a good flow of the movement of the vehicles, and the study of the recordings of the movement of the previous days enables the system to anticipate the movement now and in the future. There is a control of the paths to regulate the movement.
The current consists of an electric motor with a cable and a room counterweight. The normal maintenance of the elevator is to re-tension the cables and check the integrity of the protection systems and their sensors. The spread of elevators has increased with the arrival of electricity.
The hydraulic lifts is a piston system, through which it can move a cabin that moves only a few floors or move a system of rollers through which a cable passes that carries the cabin.
The first hydraulic lifts were very slow, and on each floor level, there was a “return” button (because almost every request from two was received the ground floor) to reduce the waiting time for the next user. It also required a column with a depth equal to the maximum height. Double column systems allowed to reduce the depth of the column in half, but the slow hydraulic system and the high cost of drilling were the reason for leaving the use of this system, especially the spread of electric motors.
The engine of modern elevators is controlled by Drive (VVVF), which controls the tension of the electrical supply in proportion to the torque required to move with acceleration or deceleration, to remain imperceptible to the occupant of the cabin (accelerating the speed of the elevators increases the person’s sense of weight: weight increases or decreases by 10 % Approximately).
Seconds (33 km/h) between 50 and 110 floors (Chicago, Toronto and Q1 Tower, Melbourne).
How about the maximum speed
The maximum speed is 17 or 18 meters per second, or 60 km / h, for the elevators of the tallest towers, such as: – Taipei 101 in Taipei or Burj Khalifa in Dubai. But in these cases, the cabin must provide adequate pressure because beyond 11 m/s there are health risks.
The acceleration needed to reach the speed of modern elevators is often constant and measured around +/- 1 meter per second squared (1 m/s²), or +/- 0.1 G. (gravity).