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The inventions of manual and electric elevators

Pre-industrial era[ edit ] Elevator design by the German engineer Konrad Kyeser 1405 The earliest known reference to an elevator is in the works of the Roman architect Vitruviuswho reported that Archimedes c. 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.

Louis XV of France had a so-called 'flying chair' built for one of his mistresses at the Chateau de Versailles in 1743. 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 built by Ivan Kulibin and installed in Winter Palace in 1793.

Elevator History

Several years later another of Kulibin's elevators was installed in Arkhangelskoye near Moscow. Industrial era[ edit ] The development of elevators was led by the need for movement of raw materials including coal and lumber from hillsides. The technology developed by these industries and the introduction of steel beam construction worked together to provide the passenger and freight elevators in use today.

  1. Com , May 1, 2014. By contrast, in Europe , wealthy families were generally found on the middle floors where they did not have to climb many flights.
  2. He then had the suspension rope cut.
  3. Some modern high-speed elevators move at up to 2,000 feet per minute 610 m per minute. Raw Materials The elevator car itself is constructed with a steel framework for durability and strength.
  4. For buildings of much over seven floors, traction elevators must be employed instead.
  5. Dual door open and door close buttons, in an elevator with two sets of doors.

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. These steam driven devices were soon being applied to a diverse set of purposes—in 1823, two architects working in LondonBurton and Hormer, built and operated a novel tourist attraction, which they called the "ascending room".

The elevator was belt-driven and used a counterweight for extra power. These quickly supplanted the earlier steam driven elevators: A water pump supplied a variable level of water pressure to a plunger encased inside a vertical cylinder, allowing the level the inventions of manual and electric elevators the platform carrying a heavy load to be raised and lowered.

Counterweights and balances were also used to increase the lifting power of the apparatus. Henry Waterman of New York is credited with inventing the "standing rope control" for an elevator in 1850. 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. Elisha Otis demonstrating his safety system, Crystal Palace1853 In 1852, Elisha Otis introduced the safety elevator, which prevented the fall of the cab if the cable broke. He demonstrated it at the New York exposition in the Crystal Palace in a dramatic, death-defying presentation in 1854, [14] [15] and the first such passenger elevator was installed at 488 Broadway in New York City on March 23, 1857.

History of Elevator Technology

Elisha Otis's elevator patent drawingJanuary 15, 1861 The first elevator shaft preceded the first elevator by four years.

An elevator shaft was included in the design, because Cooper was confident that a safe passenger elevator would soon be invented. The Equitable Life Building completed in 1870 in New York City was thought to be the first office building to have passenger elevators. 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.

His elevator ran faster and with larger loads than hydraulic or steam elevators, and 584 electric elevators were installed before Sprague sold his company to the Otis Elevator Company in 1895. Sprague also developed the idea and technology for multiple elevators in a single shaft. In 1882, when hydraulic power was a well established technology, a company later named the London Hydraulic Power Company was formed by Edward B.

Chronology of Early Lifting Devices

It constructed a network of high-pressure mains on both sides of the Thames which, ultimately, extended to 184 miles and powered some 8,000 machines, predominantly elevators and cranes. Meaker patented a method which permitted elevator doors to open and close safely. 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.

An elevator is essentially a platform that is either pulled or pushed up by a mechanical means. A modern-day elevator consists of a cab also called a "cage", "carriage" or "car" mounted on a platform within an enclosed space called a shaft or sometimes a "hoistway".

In the past, elevator drive mechanisms were powered by steam and water hydraulic pistons or by hand. In a "traction" elevator, cars are pulled up by means of rolling steel ropes over a deeply grooved pulleycommonly called a sheave in the industry.

  • The history of the elevator, if you define it as a platform that can move people and objects up and down, is actually a rather long one;
  • A ramped bar on the side of the elevator shaft activates a series of switches on the outside of the car to slow and stop the car at the proper floor;
  • By 1903, this design had evolved into the gearless traction electric elevator, allowing hundred-plus story buildings to become possible and forever changing the urban landscape;
  • A typical modern passenger elevator will have;
  • The building design integrates the elevator shaft from the beginning, and the shaft grows as the building is erected;
  • In the event of excessive car speed, the governor uses another cable to activate the emergency brake jaws which grip the guide rails and slow the car to a stop.

The weight of the car is balanced by a counterweight. Sometimes two elevators are built so that their cars always move synchronously in opposite directions, and are each other's counterweight. The friction between the ropes and the pulley furnishes the traction which gives this type of elevator its name. Hydraulic elevators use the inventions of manual and electric elevators principles of hydraulics in the sense of hydraulic power to pressurize an above ground or in-ground piston to raise and lower the car see Hydraulic elevators below.

Roped hydraulics use a combination of both ropes and hydraulic power to raise and lower cars. Recent innovations include permanent magnet motors, machine room-less rail mounted gearless machines, and microprocessor controls. The technology used in new installations depends on a variety of factors. Hydraulic elevators are cheaper, but installing cylinders greater than a certain length becomes impractical for very-high lift hoistways.

For buildings of much over seven the inventions of manual and electric elevators, traction elevators must be employed instead. Hydraulic elevators are usually slower than traction elevators. Elevators are a candidate for mass customization. There are economies to be made from mass production of the components, but each building comes with its own requirements like different number of floors, dimensions of the well and usage patterns.

Elevator doors[ edit ] Elevator doors protect riders from falling into the shaft. The most common configuration is to have two panels that meet in the middle, and slide open laterally. In a cascading telescopic configuration potentially allowing wider entryways within limited spacethe doors roll on independent tracks so that while open, they are tucked behind one another, and while closed, they form cascading layers on one side.

In less expensive installations the elevator can also use one large "slab" door: Some buildings have elevators with the single door on the shaftway, and double cascading doors on the cab. The entire drive system is in the hoistway Machine room-less elevators are designed so that most of the components fit within the shaft containing the elevator car; and a small cabinet houses the elevator controller.

Other than the machinery being in the hoistway, the equipment is similar to a normal traction or hole-less hydraulic elevator. The world's first machine room-less elevator, the Kone MonoSpace was introduced in 1996, by Kone. Equipment can be harder, and significantly more dangerous to service and maintain.

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Code is not universal for hydraulic machine room less elevators. Facts[ edit ] Noise level is at 50—55 dBA A-weighted decibelswhich can be lower than some but not all types of elevators.

Usually used for low-rise to mid-rise buildings The motor mechanism is placed in the hoistway itself The US was slow to accept the commercial MRL Elevator because of codes National and local building codes did not address elevators without machine rooms.

MRL elevators have been recognized in the 2005 supplement to the 2004 A17. Today, some machine room less hydraulic elevators by Otis and ThyssenKrupp exist; they do not involve the use of a piston located underground or a machine room, mitigating environmental concerns; however, code is not yet accepting of them in all parts of the United States.

Double-deck elevator Double-decker elevators are traction elevators with cars that have an upper and lower deck. Both decks can be serving a floor at the same time, and both decks are usually driven by the same motor. George Strakosch [35] Traditionally, these calculations have formed the basis of establishing the Handling Capacity of an elevator system. Modern Installations with more complex elevator arrangements have led to the development of more specific formula such as the General Analysis calculation.

They are up peak traffic, down peak traffic, lunch time two way traffic and interfloor traffic. Types of hoist mechanisms[ edit ] Elevators can be rope dependent or rope-free. Traction elevators[ edit ] Geared and gearless traction elevators Geared traction machines are driven by AC or DC electric motors.

Geared machines use worm gears to control mechanical movement of elevator cars by "rolling" steel hoist ropes over a drive sheave which is attached to a gearbox driven by a high-speed motor. The MG set also typically powered the relay controller of the elevator, which has the added advantage of electrically isolating the elevators from the rest of a building's electrical system, thus eliminating the transient power spikes in the building's electrical supply caused by the motors starting and stopping causing lighting to dim every time the elevators are used for exampleas well as interference to other electrical equipment caused by the arcing of the relay contactors in the control system.

The widespread availability of variable frequency AC drives has allowed AC motors to be used universally, bringing with it the advantages of the older motor-generator, DC-based systems, without the penalties in terms of efficiency and complexity.

The older MG-based installations are gradually being replaced in older buildings due to their poor energy efficiency. In this case, the drive sheave is directly attached to the end of the motor. This brake is usually an external drum type and is actuated by spring force and held open electrically; a power failure will cause the brake to engage and prevent the elevator from falling see inherent safety and safety engineering.

But it can also be some form of disc type like 1 or more calipers over a disc in one end of the motor shaft or drive sheave which is used in high speed, high rise and large capacity elevators with machine rooms an exception is the Kone MonoSpace's EcoDisc which is not high speed, high rise and large capacity and is machine room less but it uses the same design as is a thinner version of a conventional gearless traction machine for braking power, compactness and redundancy assuming there's at least 2 calipers on the discor 1 or more disc brakes with a single caliper at one end of the motor shaft or drive sheave which is used in machine room less elevators for compactness, braking power, and redundancy assuming there's 2 brakes or more.

In each case, cables are attached to a hitch plate on top of the cab or may be "underslung" below a cab, and then looped over the drive sheave to a counterweight attached to the opposite end of the cables which reduces the amount of power needed to move the cab.

The counterweight is located in the hoist-way and rides a separate railway system; as the car goes up, the counterweight goes down, and vice versa. This action is powered by the traction machine which is directed by the controller, typically a relay logic or computerized device that directs starting, accelerationdeceleration and stopping of the elevator cab.

The grooves in the drive sheave are specially designed to prevent the cables from slipping. As the ropes age and the traction grooves wear, some traction is lost and the ropes must be replaced and the sheave repaired or replaced.

Sheave and rope wear may be significantly reduced by ensuring that all ropes have equal tension, thus sharing the load evenly. Rope tension the inventions of manual and electric elevators may be achieved using a rope tension gauge, and is a simple way to extend the lifetime of the sheaves and ropes. This is a separate set of cables or a chain attached to the bottom of the counterweight and the bottom of the elevator cab.

This makes it easier to control the elevator, as it compensates for the differing weight of cable between the hoist and the cab. If the elevator cab is at the top of the hoist-way, there is a short length of hoist cable above the car and a long length of compensating cable below the car and vice versa for the counterweight.

If the compensation system uses cables, there will be an additional sheave in the pit below the elevator, to guide the cables.

If the compensation system uses chains, the chain is guided by a bar mounted between the counterweight railway lines. Regenerative drives[ edit ] Another energy-saving improvement is the regenerative drive, [41] which works analogously to regenerative braking in vehicles, using the elevator's electric motor as a generator to capture some of the gravitational potential energy of descent of a full cab heavier than its counterweight or ascent of an empty cab lighter than its counterweight and return it to the building's electrical system.

Hydraulic elevators[ edit ] Pit of a hydraulic scenic elevator with metal grating on bottom. This elevator travels 7 storeys. For higher rise applications, a telescopic hydraulic cylinder can be used. Roped hydraulic elevators use both above ground cylinders and a rope system, allowing the elevator to travel further than the piston has to move. The low mechanical complexity of hydraulic elevators in comparison to traction elevators makes them ideal for low rise, low traffic installations.

They are less energy efficient as the pump works against gravity to push the car and its passengers upwards; this energy is lost when the car descends on its own the inventions of manual and electric elevators. There are also environmental concerns should the lifting cylinder leak fluid into the ground. Electromagnetic propulsion[ edit ] Cable-free elevators using electromagnetic propulsioncapable of moving both vertically and horizontally, have been developed by German engineering firm Thyssen Krupp for use in high rise, high density buildings.

The propulsion can be done by an electric or a combustion engine. Climbing elevators are used in guyed masts or towers, in order to make easy access to parts of these constructions, such as flight the inventions of manual and electric elevators lamps for maintenance. An example would be the Moonlight towers in Austin, Texas, where the elevator holds only one person and equipment for maintenance.