Article 4- Escalator Parts & Definitions
Introduction of escalator parts and technical definitions
In this article, we intend to introduce the parts and definitions of escalators and moving walks which are useful and practical.
The authorized person is a Professional, trained individual with approval to reach restricted areas of escalators and moving walks (machinery spaces, separated machine rooms) and to work there with the purpose of assessment, testing, and support.
The competent person is an individual with the required technical knowledge, skills, qualification, and experience to perform a specific job or task.
The capacity is the maximum traffic flow of passengers transferred at optimal conditions per hour.
Angle of Inclination
The angle of inclination is the angle at which the inclined section of the escalator and moving walk meets with the horizon.
The elevation height is defined as the level difference between two finished floor surfaces.
The Horizontal Length is measured based on elevation height. After choosing the appropriate angle, in accordance with the formula for each angle, the horizontal length will be determined. It is equal to the horizontal distance between two construction beams, located on the lower and upper floors.
The nominal speed is the speed of the moving steps and pallets without load which must be equal to or less than the authorized speed.
Supporting Structure (Truss)
The truss is a chassis composed of different steel profiles on which all the machinery is installed.
The Truss soffit is a steel plate installed on the underside of the truss.
Truss Support Angle
The truss support angle is an angle steel profile which allows the escalator to rest on the construction beam of the building.
For the escalators with high elevation height and long horizontal length, a middle support should be considered to prevent deflection in the inclined section of the escalator.
The track system guides the step wheels and step chains in a circular movement inside the truss of the escalator. The track system is composed of three sections: Upper, Inclined, and Lower.
Transition Radius is the radius of the curvature of the upper and lower track.
Machinery involves all the parts, components, equipment, etc. which cause the device operation.
Machinery spaces are Internal or external spaces of the truss where parts or all the components are installed.
Step or Pallet
The step or pallet is a part on which the passengers stand. A step has horizontal and vertical plates, like stairs used in escalators, but a pallet has only a horizontal plate which is aid beside others and used in moving walks.
The standard width of the step or pallet on which the passengers stand.
Step Demarcation Cleat
Step demarcations are yellow strips on the edge of the step tread surface which are painted or made of plastic and are designed to show the passengers the safe area to step on.
Step rollers are two rollers installed under the step located on the tracks.
Step Guide Roller
The step guide roller is a device to adjust the distance between the steps and the skirt panel.
For the passengers’ safety, there must be a number of horizontal steps in both landings so that the passengers can keep their balance before the steps start the inclined movement.
The comb is a toothed part installed at both landings and meshed with the grooves of the step tread surface.
The comb plate is a platform on both landings on which the combs are installed.
Comb illumination is a lighting installed on the skirt panels on both landings used for the passengers’ safety while entering and exiting.
The floor plate is a platform surface located on both landings which are installed next to the comb plate; it also acts as the machine room cover.
The handrail is a moving rubber belt for the passengers to hold and keep their balance on the escalator or moving walk.
The handrail frame is a profile on which the handrail is fixed and guides it in a straight line in the direction of movement.
The handrail entrance is a part through which the handrail passes so it enters or exits the interior space.
Handrail Inlet Guard
The handrail inlet guard is a part made of rubber fitted at the entry point of the handrail entrance through which the handrail passes.
Handrail Return Guide
The handrail return guide is a part made of hard plastic located in the internal space, before the handrail frame and guides the handrail into the handrail frame and vice versa.
Handrail Guide Roller
The handrail guide roller is a roller that causes sliding and smoother movement of the handrail in the internal spaces.
Handrail pressure belt
The handrail pressure belt is a set of rollers located under the friction wheel through which the handrail passes so that it turns by being pressed to the friction wheel.
Handrail tension device
The handrail tension device is a set of rollers over which the handrail passes and can tighten or untighten it.
Handrail illumination is an option which is positioned beneath the handrail and gives the escalator or moving walk a more stylish look.
The balustrade is a safeguard on both sides of the escalator which provides safety for the passengers as well as supporting the handrail.
Upper Balustrade Decking
Specifically, in solid balustrades, we have upper decking, divided into inner & outer deckings, on which the handrail fame is installed.
Lower Balustrade Decking
Specifically, in slim balustrade, we have lower decking, divided into inner & outer deckings.
The skirt panel is a vertical panel of the balustrade located on both sides of the steps with a specific authorized distance on the entire route.
The skirt brush is located on the skirt panel on both sides to prevent any objects being trapped in the gap between the skirt and step.
Skirt illumination can be installed on the skirt panel to create an attractive appearance.
Direction indicators show the direction of travel; especially in case the escalators are in standby mode.
Each escalator/moving walk has two control panels, installed at the upper and lower machine rooms.
The Photoelectric Sensor has the task of detecting passenger entry into the escalator to change the escalator operational mode from stand by to normal operation.
The drive motor converts electrical energy into mechanical energy.
The flywheel is a wheel installed above the motor to manually drive the motor in emergency cases.
The gearbox is a device which is composed of gears and gear trains, used to give speed and torque conversions, from the drive motor to the main drive shaft by a chain.
Main Drive Shaft
The main drive shaft is located in the upper sections and is composed of seven main parts including drive sprocket, major axis, main axis chain wheel, drive wheel, turn table, bearings, and support plate on which the step chains turn around.
Handrail Drive shaft
The handrail drive shaft is composed of four main parts including friction wheel, handrail drive axis, lager, and handrail axis chain wheel which is located in the upper sections and turns the handrail
The friction wheel is a large wheel that has a rubber edge located inside the handrail and causes its turning.
The Brake load equals the weight of the steps/pallets (considering the load of passengers standing on them), which the brake system must stop.
Main Drive Chain
The drive chain is a chain that transmits the motive force from the gearbox shaft to the escalator's main drive shaft.
Handrail Drive Chain
The drive chain is a chain that transmits the motive force from the main drive shaft to the handrail drive shaft.
The step chain is two sets of chains on both sides of steps composed of rollers at regular intervals which are linked together by several axels on which the escalator steps are mounted.
The newel chain is a chain with several small bearings that are located at the curved ends of the balustrade, under the handrail, to cause a smoother movement of the handrail.
Ceiling Opening Length
In order to install an escalator in a building, a ceiling opening must be considered on the upper floor with the appropriate length and width.
In order to install an escalator, a pit must be considered on the lower floor with an appropriate length, width, and depth.
Escalators, based on their usage, are divided into two categories of “Commercial” and “Infrastructure”.
Escalators, based on their installation environment, are divided into three categories of “Indoor”, “Semi-outdoor” and “Fully-outdoor”.
The safety system is an arrangement of safety circuits and monitoring devices used to ensure the safety of the electrical system.
The safety devices are safety switches, fail-safe circuits performing safety functions used in the escalator safety system.
The Fail-safe Circuit is a device to define failure mode behavior in electrical and electronic systems.