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An escalator is a conveyor type transport device that moves people. It is a moving staircase with steps that move up or down using a conveyor belt and tracks keeping each step horizontal for the passenger. However, the escalator began as an amusement and not as a practical transport. The first patent relating to an escalator-like machine was granted in 1859 to a Massachusetts man for a steam driven unit. On March 15 1892, Jesse Reno patented his moving stairs or inclined elevator as he called it. In 1895, Jesse Reno created a new novelty ride at Coney Island from his patented design, a moving stairway that elevated passengers on a conveyor belt at a 25 degree angle.
The escalator as we know it was later re-designed by Charles Seeberger in 1897, who created the name 'escalator' from the word 'scala', which is Latin for steps and the word 'elevator', which had already been invented.
Charles Seeberger, together with the Otis Elevator Company produced the first commercial escalator in 1899 at the Otis factory in Yonkers, N.Y. The Seeberger-Otis wooden escalator won first prize at the Paris 1900 Exposition Universelle in France. Jesse Reno's Coney Island ride success briefly made Jesse Reno into "the" escalator designer and he founded the Reno Electric Stairways and Conveyors company in 1902.
Charles Seeberger sold his patent rights for the escalator to the Otis Elevator Company in 1910, who also bought Jesse Reno's escalator patent in 1911. Otis then came to dominate escalator production, and combined and improved the various designs of escalators.
According to Otis, in the 1920s, Otis engineers, led by David Lindquist, combined and improved the Jesse Reno and Charles Seeberger escalator designs, and created the cleated, level steps of the modern escalator in use today.
Escalators are one of the largest, most expensive machines people use on a regular basis, but they're also one of the simplest.
At its most basic level, an escalator is just a simple variation on the conveyer belt. A pair of rotating chain loops pull a series of stairs in a constant cycle, moving a lot of people a short distance at a good speed.
The core of an escalator is a pair of chains, looped around two pairs of gears. An electric motor turns the drive gears at the top, which rotate the chain loops. A typical escalator uses a 100 horsepower motor to rotate the gears. The motor and chain system are housed inside the truss, a metal structure extending between two floors.
Instead of moving a flat surface, as in a conveyer belt, the chain loops move a series of steps. The coolest thing about an escalator is the way these steps move. As the chains move, the steps always stay level. At the top and bottom of the escalator, the steps collapse on each other, creating a flat platform. This makes it easier to get on and off the escalator.
Each step in the escalator has two sets of wheels, which roll along two separate tracks. The upper set (the wheels near the top of the step) are connected to the rotating chains, and so are pulled by the drive gear at the top of the escalator. The other set of wheels simply glides along its track, following behind the first set.
The tracks are spaced apart in such a way that each step will always remain level. At the top and bottom of the escalator, the tracks level off to a horizontal position, flattening the stairway. Each step has a series of grooves in it, so it will fit together with the steps behind it and in front of it during this flattening.
In addition to rotating the main chain loops, the electric motor in an escalator also moves the handrails. A handrail is simply a rubber conveyer belt that is looped around a series of wheels. This belt is precisely configured so that it moves at exactly the same speed as the steps, to give riders some stability.
The escalator system isn't nearly as good as an elevator at lifting people dozens of stories, but it is much better at moving people a short distance. This is because of the escalator's high loading rate. Once an elevator is filled up, you have to wait for it to reach its floor and return before anybody else can get on. On an escalator, as soon as you load one person on, there's space for another.
1. On March 15 1892, Jesse Reno patented his moving mechanism or inclined elevator as he called it.
2. An electric motor turns the drive gears at the top, which rotate the chain loops.
3. At the top and bottom of the escalator, the steps collapse on each other, creating a flat surface.
4. Each step in the escalator has several sets of wheels, which roll along two separate tracks.
5. The motor and chain system are housed inside the truss, a metal structure extending between two floors.
6. A handrail is simply a plastic conveyer belt that is looped around a series of wheels.
7. At its most basic level, an escalator is just a simple variation on the conveyer belt.
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Дата публикования: 2015-09-17; Прочитано: 287 | Нарушение авторского права страницы | Мы поможем в написании вашей работы!