When the use of an elevator would be impossible or impractical, the use of escalators is the best option. Escalators are widely used nowadays especially in main areas like department stores, shopping malls, transit systems, convention centres and large hotels. The escalator is used as an alternative to the mundane staircase, elevators and the moving sidewalk seen mainly in airports.
In riding an escalator, you just got to take a step in and it will carry you to which direction you intend to go. When an escalator does not function well, it simply becomes a normal staircase. This is the good thing about it because unlike other conveyances which become useless when they break down, escalator can still be used.
Escalators as a machine have essential parts and one of the most important parts is the escalator step chain. The steps are where we land our feet while riding an escalator. These are the steps which carries us to the next floor. The escalator step chain continuously pulls the steps from the bottom platform and back to the top in an endless loop.
Instead of moving a flat surface, as in a conveyer belt, the chain loops move a series of steps. This is why passengers easily get on and off the escalator because it creates a flat platform. The tracks are spaced apart in such a way that each step will always remain level. 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.
The escalator step chain is guided by the track system which is built into the truss. There are two tracks: one is called the step-wheel track and the other is called the trailer-wheel track. The first one is the track for the front wheels of the steps. The later one is for the back wheels of the steps.
The relative positions of these tracks cause the steps to form a staircase as they move out from under the comb plate. Along the straight section of the truss the tracks are at their maximum distance apart. This configuration forces the back of one step to be at a 90-degree angle relative to the step behind it. This right angle bends the steps into a stair shape.
The two tracks converge in the top and bottom part so that the front and back wheels of the steps are almost in a straight line. This causes the stairs to lay in a flat sheet-like arrangement, one after another, so they can easily travel around the bend in the curved section of track. The tracks carry the steps down along the underside of the truss until they reach the bottom landing, where they pass through another curved section of track before exiting the bottom landing. At this point the tracks separate and the steps once again assume a stair case configuration. This cycle is repeated continually as the steps are pulled from bottom to top and back to the bottom again.
