Escalators are a type of moving staircase which is used in a variety of locations. They can be found in airports, department stores, shopping malls and public buildings.
They are made of metal and are a safe alternative to walking down stairs. The steps are attached to a system of tracks that keep them level.
The steps of an escalator are the part of the escalator that moves a passenger safely up and down the escalator. They are usually made of metal, but in the past they were sometimes built with wooden steps.
Each step has two sets of wheels that roll on separate tracks. The upper set (the ones near the top of each step) are connected to the rotating chains and are pulled by the drive gear at the top of the escalator, while the lower set glides along its own track and follows behind the first.
At the top and bottom of the escalator, the tracks meet at a right angle, which forces the steps into a shape that is reminiscent of a staircase. This causes the front and back wheels of each step to almost align in a straight line, making it possible for them to travel around a curved section of track without falling out of place.
As the steps pass through the curved sections of the escalator, they are also locked together by grooves in the bottom of each step. This keeps foreign objects from slipping through the gap between the step and its comb plate, which could otherwise cause the escalator to stall or break down completely.
These grooves also make it difficult for liquids to pool up and become trapped in the gap between the step and its comb plates. This prevents dangerous substances from becoming trapped inside the escalator, while also protecting passengers who are prone to getting wet.
There are several types of escalators, but the most common is the step type. This style of escalator has steps that go up and down, flat, then up and down again.
Some escalators also have a reversal feature where the steps are able to move in reverse at the landings and then revert to their normal position when they return to the starting point. This is a safety feature that helps to avoid accidents with people walking underneath the steps and allows for more control over the direction of the escalator.
Escalators are a type of moving stairway that transports passengers between floors in buildings. They are commonly found in areas where elevators would be impractical, such as shopping malls, airports, public buildings and transit systems.
The steps of an escalator are connected in series, with two sets of wheels on each step that roll along a track. The upper set (the wheels near the top of each step) is attached to a rotating chain that is pulled by escalator steps the drive gear at the top of the escalator, while the lower set (the wheels just following behind the upper set) glides along on its own track.
This allows the steps to always stay level while they move, and at the top and bottom of each step, they collapse on each other to create a flat platform for users to walk on. This makes it easier for people to step on and off the escalator without tripping or falling off, and prevents them from tumbling out of the stairs as they go up or down.
Another safety feature of an escalator is a comb plate, which consists of a series of cleats that mesh with matching cleats on the steps to minimise the space between the stair and the landing. These cleats also allow for a wider stairway to be built than is possible by using only stairs alone, so that the escalator can handle more passengers at a time.
In addition to the comb plate, many modern escalators come with an optical or physical missing step detector that will turn off the escalator when no step is found when one is expected. This sensor is usually located at the stair hold downs and is designed to alert passengers if the escalator is not operating as intended.
Other safety features of an escalator include handrail inlet switches, which guard the opening where the handrail enters and exits the escalator. If something gets caught in this gap, the escalator stops functioning and will generate a hard fault in the control panel. Skirt brush – a long, continuous brush made of stiff bristles that runs up the side of the escalator just above the step level helps to keep loose garments and curious hands away from this dangerous gap.
The landing platforms of an escalator are located at both ends and contain the curved sections of the tracks as well as gears and motors that drive the stairs. The top platform holds the motor assembly and main drive gear, while the bottom platform accommodates the step return idler sprockets. The two platforms also anchor the ends of the truss.
There are four basic types of escalators: parallel, criss-cross, multi-station and multiple parallel. Each type of escalator has its own unique design and function.
Typically, parallel escalators are positioned side-by-side and move in opposite directions. They are mainly used in departmental stores and shopping centers.
Escalators arranged in a criss-cross manner are called stacked and minimize space requirements. They are usually preferred in malls and shopping centers to maximize floor space and stimulate the interest of potential buyers.
Another way to reduce space is by stacking the escalators together in one direction, as shown in this illustration. This arrangement is often seen in high-traffic areas, such as city subway stations.
To ensure safe operation, escalators have an integral track system that continually pulls the steps from the bottom platform to the top. During this process, the escalator steps continually erect and then collapse as needed.
Each of the steps is pulled by a chain that continually loops around the top and bottom tracks and back to the truss. The front and back wheels of the steps are almost in a straight line as they travel down along the truss’s first section of tracks, and then they bend into a staircase when they pass through another curved section of tracks at the bottom landing.
In order to keep the steps safe, there is a comb plate that sits between the floor plate and the moving stairs. The comb plate is designed with a series of cleats that mesh with matching cleats on the edge of the steps, and it minimizes the gap between them.
The comb plate is also levelled with the rest of the floor and hinged to make maintenance easy. The comb plate is covered with a cover that matches the cleats on the moving steps. This prevents objects and people from getting caught in the gap between the escalator steps and the landing.
Escalators have handrails that passengers use to keep their hands steady while riding the escalator. The handrail is attached to the step chain and is pulled escalator steps along its own track by a series of pulleys, keeping it at the same speed as the steps.
The escalator handrail is made from a rubber ring that flexes and stretches as it rolls around the escalator system. As the rubber wears out, the handrail gets slightly longer and slower than the steps. This means that passengers must be more careful when stepping off an escalator, to avoid falling.
In many escalators, the handrail is shaped like an “A” or a “C.” The “A” shape is designed to be smooth and require minimal friction, while the “C” is designed with a tab inside that concentrates the friction force in a central location. These are the two most common handrail shapes in the market, but both can be expensive and have limited lifespans.
There is also a U.S. patent that describes a handrail construction that allows the handrail to resist reverse bending, which is a common issue on some escalators. The invention addresses this by modifying the structure of the handrail’s body, making it flattened C-shaped instead of having inwardly directed lips that engage the guide rail.
This allows the handrail to resist reverse bending without losing its gripping strength, as is the case with other handrails in the market. A special tool is used to measure the handrail’s lip strength, and the patent states that the handrail’s average lip strength is about 70 newtons, which is a significant improvement over what is normally found in the market.
Another patented construction is the T-shaped handrail that consists of several layers of rubber-coated fabric in a continuous band. The outer layer is made from normal rubber compositions, while the inner layer contains a woven fabric that can be easily removed by passengers to replace it with a new one.
There is a retaining element angularly embodied in each of the separate elements and an elastically deformable bellows section is attached to the angularly embodied retaining element by vulcanization, so that the separate elements can be fixed together with respect to each other using rubber nubs. This method can reduce the amount of rubber material that must be used to assemble the separate elements and prevents them from coming apart due to the repeated use of the handrail.