Friday 24 June 2016

How Escalator Handrails Function



Escalator Handrails is a very complex product. It is essentially a rubber product that must be both extremely flexible and extremely rigid at the same time. Escalator Handrails require a similar flexibility and durability as printer rollers. Handrails are extremely resistant to aging and ozone corrosion, and they operate longer without cracking or slipping. Drive components moved down into the unit, giving less room for the handrail to curve around the drive wheel. There is also the broken handrail safety device. If a broken handrail is detected, the device will stop the escalator to ensure passengers’ safety.  
Then escalator handrail drive moves the handrail along the handrail tracking system through traction on the V-shaped handrail underside. The handrail drives consists of the following: 

The Handrail Drive and Idler Sheaves 
They are V grooved sheaves located in the upper newel ends of the escalator. Idler sheaves are V grooved sheaves located in the lower newel ends of the escalator. The handrail drive sheave drives the handrail in its journey around the escalator while the idler sheave reverses the direction of the handrail at the lower end.

The Handrail Drive Chain Sprockets
They are located on the handrail drive sheave and the outboard end of the bull gear shaft. Handrail drive sprockets are linked by the handrail drive chain and provide a direct link between the bull gear and handrail drive sheave.


The Handrail Drive Chains
They are double stranded chains and are the mechanical link between the dual toothed drive chain sprockets. The drive chain sprockets and handrail drive chain coming to transfer power from the bull gear shaft to the handrail drive sheave. The Handrail drive chain has an adjustable take-up sprocket to keep the drive chain snug. The handrail drive chain receives lubrication from an enclosed bath system.

 The Handrail Take-Up Devices

they are located directly downhill from the handrail drive sheaves. The handrail take-up devices remove slack in the handrail to provide the proper amount of slack in the handrail required to drive the handrail. The short handrail take-up device can be adjusted to remove slack from the handrail. The long handrail take-up device can pivot from the center and be adjusted at the uphill end to remove slack from the handrail. The long handrail take-up device is always required. 

The Handrail Support Rollers
 

They are located at various intervals down the incline. Their function is as follows: 
  • They support the handrail and protect it from coming into contact with the track brackets or any other truss components which may damage the handrail. 
  • They help provide the correct loop of slack in the handrail at the lower end which proves the traction to drive the handrail. 

Therefore, the escalator handrail can be purposefully adapted to specific guide elements of specific customers without having to use particularly massive handrails. In escalators and moving walkways the flexible endless profile band, which runs synchronically with the steps or the plate band, secures the passenger safety transport.