Intro to Elevators and Elevator Technicians: Chapter 1
Intro to Elevators
By the end of this module, you should be able to describe the following:
What an elevator is,
Benefits of elevators, and
Importance of elevators. Skip to quiz!
What is an Elevator?
An elevator, a. k. a. a lift, is a machine that transports people or freight between levels, decks, or floors of a building. Elevators are usually cable-assisted, hydraulic cylinder-assisted, or roller-track-assisted.
A cable-assisted elevator equips traction cables and a counterweight system powered by electric motors.
A hydraulic pump powers a hydraulic cylinder-assisted elevator. A hydraulic fluid is pumped to raise a cylindrical piston. For example, a hydraulic jack is raised by hydraulic fluid.
Wheelchair accessibility laws made elevators compulsory in the new multi-story buildings.
In the past, workers used elevators for material handling in factories, warehouses, and mines. In 1852, Elisha Graves Otis created the first elevator safety device and started an Elevator Company. The Otis Elevator Company (now Otis Worldwide Corporation) is the largest company in the elevator industry.
The benefits of an elevator are:
It transports heavy objects like luggage or packages between floors.
It provides a smooth and relaxing ride from floor to floor for your comfort.
Children and the elderly can travel safely between various floors without the potential injuries of a staircase.
It can be hard for people (especially children and the elderly) who live in three or more-storied buildings to make frequent trips up or down using staircases. 90% of people use elevators. Elevators are also especially helpful for medical patients, hotel guests, elders, and young children.
Elevators make everyone’s lives easier by moving between different floors faster, transporting goods easier, and providing a comfortable and relaxing way to travel up and down large buildings.
History
The first mention of an elevator is from the Roman architect Vitruvius, who documented Archimedes’ first elevator around 236 BC. Later sources showed that elevators were cabins on a rope powered by people or animals.
In AD 80, around 25 elevators were finalized to raise animals to the floor in the Roman Colosseum. 8 men powered each elevator that carried about 600 pounds, equivalent to 270 kg, up to 23 feet or 7 m.
King Louis XV of France built a flying chair for one of his mistresses at the Palace of Versailles. Hydraulics came into the picture during the industrial revolution and sped things up. Later, pulley gear systems with counterweights were introduced.
Elevators made it possible to build high-rise buildings. Today, the skylines of most major cities worldwide are defined by the distinctive silhouettes of their tallest buildings.
Until 1930, the Eiffel Tower was the tallest man-made structure. Today the Burj Khalifa holds the title of the tallest building in the world. For such massive buildings, you must use an elevator instead of staircases and escalators. Effortlessly visiting the tops of buildings like these is only possible with modern elevator technology.
The invention of elevators has impacted how developers use plots in major cities with expensive land. Over time, they started building taller instead of building wider.
Everyone can access elevators regardless of age or physical condition. The elevators are a better and safer alternative to escalators for children and disabled persons.
Today, homeowners can install a domestic elevator to make their homes more accessible in their later years.
In the early 1600s, Warehouses and manufacturing plants employed manually operated elevators to lift freights. In 1853, when modern elevators were developed, elevators were installed in various industries.
People started using them in the following industries:
Business Center,
Hospitality,
Medical,
Education Industry,
Automobile Dealership,
Storage Facility, and
Parking Garages.
Modern elevators are manufactured in various styles for passenger and freight transportation. Passenger Elevators can be used in ships, dams, and specialized structures like rocket launchers. In high-rise construction, heavy-lift, rapid-descent elevators are used.
Freight elevators, also known as workhorses, are beneficial for transporting materials and goods in warehouses, manufacturing plants, shopping malls, and seaports. These elevators are made of strong materials intended for commercial and industrial use.
An elevator is a machine that transports people or freight between levels, decks, or floors of a building. Elisha Graves Otis started the first Elevator Company. Elevators are being used in various industries.
Types of Elevators
By the end of this module, you should be able to describe the following:
Types of Elevators, and
How different types of elevators work. Skip to quiz!
Types of Elevators
In General, there are four types of elevators. They are:
Hydraulic Elevator,
Traction Elevator,
Machine-Room-Less Elevator, and
Vacuum Elevator.
Hydraulic Elevators
A Hydraulic elevator is powered by liquid pressure. It is powered by a piston placed inside a cylinder using hydraulic fluid
A hydraulic pump powers a hydraulic cylinder-assisted elevator. A hydraulic fluid is pumped to raise a cylindrical piston. For example, a hydraulic jack is raised by hydraulic fluid.
The benefits of hydraulic elevators are:
It is easy to install relative to other elevators.
It is less expensive for installation and maintenance.
It is ideal for the transportation of heavy loads.
There are three types of hydraulic elevators. They are:
Holed hydraulic elevators,
Holeless hydraulic elevators, and
Roped hydraulic elevators.
We will learn about each type of hydraulic elevator soon.
A holed hydraulic elevator is also known as a direct-acting lift. The cabin is mounted on the piston that travels inside a cylinder. The hole is dug into the ground and, the cylinder is placed inside the ground.
The depth of the cylinder into the ground is equal to the height of the rise. The cabin rises as the fluid pumps from the reservoir to the cylinder. The cabin descends as the fluid returns from the cylinder to the reservoir.
The hole less hydraulic elevators were developed in the late 1970s or 1980s. The cabin is mounted on the piston that is mounted inside the Hostway. Digging deep holes into the ground is not required.
These elevators are helpful for buildings that are built on bedrock with unstable soil. Here digging a hole for the elevator is impractical. Let’s watch a video to understand how a hole less hydraulic elevator works.
A roped hydraulic elevator uses a combination of hydraulics and cables. The cylinder is placed inside the Hostway. A pulley is attached to the piston.
The cables hold the cabin in place. One end of the cable is attached to the cabin, and the other is at the bottom of the Hostway. Manufacturers may use a governor to avoid the risk of the cabin freefalling if the rope breaks.
The pulley provides a 2:1 movement ratio. The cabin moves 2 feet for every foot that the piston moves. Let’s watch a video to understand how a roped hydraulic elevator works.
Traction Elevators
Traction Elevators are the most common type of elevator, also known as electric elevators. The rolling steel ropes over a pulley pull up the cabin and are balanced by a counterweight.
Nowadays, elevators use flat steel belts with carbon fiber core and high-friction coating. They are light and do not require lubricant or oil.
The benefits of a traction elevator are:
They are more energy efficient than hydraulic elevators in high-rise buildings.
They ride smoother.
There are two types of traction elevators. They are:
Geared traction elevators, and
Gearless traction elevators.
We will learn about each type of traction elevator soon.
As the name suggests, the pulley is turned by a worm and gear reduction unit powered by an electric motor. The gear reduction provides an advantage of requiring a less powerful motor to turn the pulley. It is stopped and held at the selected floor by an electric brake between the motor and the reduction unit.
These elevators usually move at 38 to 152 meters per minute and can handle loads up to 13,600 kgs. Let’s watch a video to understand how a geared traction elevator works.
Otis invented a gearless traction elevator in 1913 that was first installed in the Woolworth Building in New York City. As the name suggests, the pulley is turned by an electric motor. Thus, these elevators travel faster than geared traction elevators.
This system could be used in buildings of any height and operate faster. These elevators typically travel at speeds greater than 2.5 meters per second. Some elevators can travel at speeds as low as 0.5 meters per second, depending on the application.
Depending on the model and configuration, they can reach speeds of up to 20.5 meters per second. For example, the Shanghai World Financial Center elevator operates at a speed of 20.5 meters per second.
MRL Elevator
Unlike elevators that you learned recently, Machine-Room-Less (MRL) Elevators don’t equip a separate machine room. A machine room contains all the drive, control units, and disconnect switches. MRL Elevators have these components installed in the Hostway.
There are two types of MRL elevators. They are:
Hydraulic MRL elevators, and
Traction MRL elevators.
We will learn about each type of MRL elevator soon.
Hydraulic MRL Elevators do not have a separate room to store the hydraulic machinery; instead, they are set up in the elevator pit. The controller is often on the ground floor, mounted to a wall next to the elevator. These elevators can save money, time, and space during construction.
The traction hoisting machine is positioned either on top of the Hostway or the bottom and does not have a separate machine room. It saves significant construction space.
Vacuum Elevator
The Vacuum Elevator comprises a smooth vertical cylinder and a coaxial cabin that moves up and down via air suction. Its basic operation is based on the ascending push generated by the difference in atmospheric pressure between the top of the cabin and the atmospheric pressure beneath the cabin.
This elevator has an airtight seal on the top of the cabin. While the elevator moves upwards, the air is removed from the upper part of the Hostway using turbines to create vacuum pressure to lift the cabin upwards. The shaft's lower part allows free air to enter at atmospheric pressure.
The air is released back through a valve into the Hostway at a controlled speed to lower the elevator. The cabin has locking devices to stop it at the upper and lower limits of travel. In the event of a free fall, a safe braking device activates.
At the top of the Hostway, multiple pneumatic turbines remove the air from the Hostway to lift the cabin. An electronic valve returns the air into the Hostway to lower the cabin.
The benefits of a vacuum elevator are:
There is no need for a pit, machine room, or hoist. Thus, It can be relocated anytime, in any location.
It is a low-maintenance elevator.
There is no need for a backup power supply.
It does not consume energy during the descent.
It automatically descends to the ground floor and opens the door during a power failure.
It starts and stops very smoothly.
Let’s watch a video to understand how a vacuum elevator works.
There are four types of elevators. They are:
Hydraulic Elevator,
Traction Elevator,
Machine-Room-Less Elevator, and
Vacuum Elevator.
There are three types of hydraulic elevators. They are:
Holed hydraulic elevators,
Hole less hydraulic elevators, and
Roped hydraulic elevators.
There are two types of traction elevators. They are:
Geared traction elevators, and
Gearless traction elevators.
Question #1: What is the purpose of an elevator? (Select all that apply)
To travel through different levels.
To travel from one location to another.
To carry goods through different levels.
To bring value to a building.
Scroll down for the answer...
Answer: To travel through different levels, To carry goods through different levels and To bring value to a building.
The elevator brings value to a building where people can readily travel through different levels. Also, heavy goods can be carried through different levels.
Question #2: Elevators are not compulsory in a multi-story building.
True
False
Scroll down for the answer...
Answer: False
Due to wheelchair accessibility laws, elevators are compulsory in the new multi-story buildings.
Question #3: Do you know how many percentages of people in a building use elevators?
60%
70%
80%
90%
Scroll down for the answer...
Answer: 90%
Elevators are used by 90% of the people in a building.