Handrail Friction Checking Device for Conveyor Safety
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Solution Overview
Problem
The existing passenger conveyor handrail drive mechanisms face issues with frictional force degradation due to worn fabric layers and misalignment of wheels or rollers, leading to operational failures and the need for regular friction checks.
Innovation Solution
A handrail friction checking device comprising a gripper, a spring mechanism, and a sensor system that determines slippage by applying a spring force opposed to the handrail movement and detecting engagement with a limit switch, allowing for remote assessment of sufficient frictional driving force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If wheels or rollers are used in the handrail drive mechanism to generate frictional driving force, then the handrail can be driven in the desired direction, but the friction causes wear to the fabric layer on the handrail
Solution Approach 1:
The patent applies preliminary action by implementing a friction checking device that proactively monitors the frictional driving force before it degrades to failure levels. The device includes a sensor that detects the friction force between the wheel/roller and handrail, and a controller that compares this force against predetermined thresholds to schedule maintenance before the fabric layer is significantly worn or operational failure occurs.
2Productivity
If the handrail drive mechanism operates continuously to drive the handrail, then passenger conveyor functionality is maintained, but misalignment or displacement of wheels or rollers may occur affecting frictional driving force
Solution Approach 1:
The patent implements feedback by using a sensor to continuously or periodically detect the actual frictional driving force between the wheel/roller and handrail during operation. The controller receives this feedback signal and compares it against predetermined thresholds, enabling the system to monitor friction force variations caused by misalignment or displacement and trigger maintenance alerts when friction falls outside acceptable ranges.
3Reliability
If regular friction checks are performed to detect slippage between handrail and drive mechanism, then operational failures can be prevented, but the checking device adds complexity to the system
Solution Approach 1:
The patent replaces complex mechanical checking mechanisms with a sensor-based detection system. Instead of using mechanical devices to physically test friction, the invention uses a sensor to detect the frictional driving force and a controller to process this information, thereby reducing mechanical complexity while maintaining or improving detection accuracy and reliability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables regular and remote monitoring of handrail friction, preventing operational failures by identifying insufficient frictional forces and facilitating timely maintenance, thus ensuring continuous and safe operation of passenger conveyors.
Implementation Method 1
a first spring with one end of the first spring being fixed and the other end being connected to the handrail gripper so that the first spring can apply a spring force which is opposed to the direction of handrail movement to the handrail gripper
Implementation Method 2
a sensor which is disposed in a way that it is distanced from the handrail gripper and can be triggered by the handrail gripper when the handrail gripper moves along with the handrail
Implementation Method 3
Typical arrangements rely upon wheels or rollers that frictionally engage the handrail to generate enough friction to drive the handrail in the desired direction
Data Source
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AI summary
A handrail friction checking device comprises a handrail gripper for gripping the handrail and movable together with the handrail, a spring with one end of the spring being fixed and the other end being connected to the handrail gripper so that the spring can apply a spring force which is opposed to the direction of handrail movement to the handrail gripper when the handrail gripper moves along with the handrail and a sensor which is disposed in a way that it is distanced from the handrail gripper and can be triggered by the handrail gripper when the handrail gripper moves along with the handrail.