What is an Elevator?

Elevators are vehicles used to transport goods and people vertically or horizontally. With the construction of higher and deeper structures, the need for people and goods to reach upper and lower floors made elevators necessary.

History
In the 19th century, freight elevators were used in some mines and factories to transport coal and necessary materials. The first elevators that did not endanger people's life safety were built in the mid-19th century. Until this period, buildings in cities were built at a height where people could climb up by stairs, at most five or six stories high.

These safe elevators worked with steam power. In these elevators, the steam engine rotated a drum, and the rope pulling the elevator cabin was wrapped around this drum, just like in reel fishing rods. Elisha Graves Otis invented the elevator.

Electric Elevators
The rope-wound drum system used in old elevators is still used in some elevators today, by turning it with an electric motor instead of a steam engine. However, most electric elevators are now traction type. In these elevators, the elevator car is attached to one end of the suspension ropes, and a counterweight that balances the weight of the car is attached to the other end. Each of the suspension ropes fits into a separate groove on a pulley or sheave located at the top of the elevator shaft. This pulley, which is powered by an electric motor, moves the ropes as it rotates. Thus, the elevator moves in one direction while the counterweight moves in the opposite direction.

Today's elevators are equipped with many safety devices that prevent the car from going up and down too quickly, and from going beyond the top or bottom floor level, and from passing the top or bottom floor level. Even if these devices were not working, it would be impossible for the elevator to pass the top floor and rise high enough to touch the devices at the top. Because when the car reaches the top floor, the counterweight sits on the buffers located at the bottom of the shaft, and the ropes are loose and cannot pull the car up any higher.

Some modern elevators are also of the piston-electric type. These work just like the old hydraulic elevators, except that instead of water, oil is used to prevent rusting and freezing. The oil, which is pressed into the cylinder by an electric pump, is discharged into electric valves. These elevators are used in low-rise structures, especially in factories for lifting heavy loads, and in the elevator platforms of aircraft carriers and car wash-lubrication stations.

Electronically Controlled Elevators
Even after electric elevators became widespread, elevator attendants were still needed for a long time to control the elevator's ascent and descent and to open and close the cabin doors. It was not until the 1890s that passengers were able to operate the elevator themselves by pressing the buttons in the cabin. These elevators, which were initially small and very slow, could only be used in residences or in office buildings with a few floors where a small number of people entered and exited.

As the science of electronics advanced, automatic control systems were developed for fast elevators used in busy buildings. These automatic electronic devices also serve as a "command table" that distributes tasks in buildings with several elevators. These devices regulate the direction of the elevators according to the passenger traffic in accordance with the given program. For about 30 years, most elevators in high-rise buildings have been fully automatic. These elevators are much more efficient, faster and more reliable than elevators controlled by human hands.

Automatic Elevators
In the cabin of automatic elevators, there is a numbered button for each floor of the building on a panel placed on one or both sides of the door. All a person getting on the elevator does is press the button for the floor they want to go up or down. A light inside the button that is pressed illuminates to inform passengers getting on which floor the elevator will stop at. The doors automatically close very shortly after the button is pressed and the elevator starts moving on its own. It automatically slows down as it approaches the floor it will stop at and stops when it reaches the same level as the floor door. While the elevator is going up, it also stops on floors where other passengers are pressing the exit buttons on the panel next to the elevator doors in the corridors of the building. It also responds to landing calls while going down. Since the automatic control mechanism stores all calls in its memory to answer them in order, many passengers can use the elevator during the same landing or ascent.

When the elevator reaches the floor level and stops, the doors open automatically; and when all the passengers' ascents and descents are finished, they slowly close. If a passenger is caught between the two wings while all the doors are closing, an electronic device detects this and stops the doors without hitting the passenger. But this is only a momentary pause. If someone tries to force the doors open, the door wings gently push the passenger away and allow the elevator to continue on its way.

Programming Elevators
In tall buildings with many elevators, all 

The operation of elevators is directed by automatic devices connected to computers. These devices are programmed to regulate the ascents and descents of the elevators according to passenger traffic. In a very busy building, six different programs are usually applied according to the flow of passenger traffic between the morning and evening hours. Since people are in a hurry to get to work in the early hours of the day, most of the elevators are operated in the direction of ascent. In the remaining part of the morning, ascents and descents are balanced. When people go to lunch, ascents are more intense, and when they return from lunch, ascents and descents are more intense. Then, for a long time, ascents and descents are balanced. At the end of the workday, most of the elevators are programmed to operate in the direction of descent. Finally, except for one or two elevators reserved for night service, the electronic system automatically stops all elevators.

Source: Basic Britannica Elevator Article and Wikipedia

What is an Elevator
An electrically operated vehicle that carries people, loads, from one floor of a building to another or to high places is called an elevator.

An elevator is a machine system consisting of a platform cabin that is used to lower and raise loads or people vertically to low or high places.

Even in ancient times, people used machines to lift heavy loads. According to the work written by the Roman architect Vitarius in 26 BC, 236 years before Christ, a number of machines were used to lift loads in Rome. Similarly, there were structures similar to cabinets in the palaces of Roman Emperors.

In the eighteenth century, a French architect named Velayer offered a vehicle he called "Flying Furniture" to people. This vehicle was kept in balance by means of a counterweight. In order for it to move, a slave or servant had to pull the handle. A French engineer named Edoux also built a new type of lifting machine in 1867 and called it an "elevator".

Elevators are divided into types such as freight and passenger elevators; hydraulic, manual, hydroelectric and electric elevators according to their purposes and usage.

Hydraulic elevator:
Hydraulic elevators work with liquid pressure. The chamber is placed on a thick piston. The piston rod enters a cylinder that is inserted underground as high as the building. Liquid is sent to the cylinder with powerful pumps and the piston starts to rise upwards. When the elevator is to be lowered, the liquid pressure on the piston is reduced. Hydraulic elevators are not used in very high buildings. With the development of elevators operating with electric power, they have lost their importance.

Electric elevator:
They are machines of various sizes and powers that operate with electric power and have a very wide range of use. Thanks to these, it is possible to climb to the top floors of buildings with 90-95 floors or even higher in a short time. The mechanism of these electric elevators is quite simple. One end of a steel rope, whose diameter and strength have been determined as a result of calculations and applications, is connected to the ceiling of the elevator room and the other end is connected to an iron weight called a counterweight. The steel rope travels through a pulley system consisting of a number of pulleys at the top of the space. Its weight is approximately the weight of the elevator room. Thanks to the counterweight, the load on the motor is lightened. With the counterweight, the elevator almost stays in balance.

After entering the elevator room and closing the doors, the electric motor is activated when the button for the desired floor is pressed. The pulleys in the plank system on which the ropes are wrapped rotate. With the rotation of the rope, the elevator is pulled upwards from the shaft.

Various precautions have been taken in electric elevators against any kind of accident possibility. In the event that the elevator ropes break, the steel claws close to the guide rails automatically spring from their places and hold the vertical rails around the shaft where the room goes back and forth. In addition, steel piston cylinders containing oil have been placed at the bottom of the room in order to reduce the hardness of the fall.

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