Driving Pulley for Flexible Handrail with Liquid-Filled Tire

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Solution Overview

Problem

Existing wheels for driving flexible handrails on escalators and moving walks suffer from slip-stick effects, noise, and excessive wear due to bulge formation, which are caused by the elasticity and gas-filled nature of the driving wheel tires.

Innovation Solution

A wheel design featuring a solid, dimensionally stable, yet elastically deformable middle layer with an inner and outer layer, where the outer layer is prestressed to maintain frictional contact with the handrail, preventing slip-stick effects and bulge formation by ensuring consistent friction and reduced material deformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a gas-filled elastic driving wheel tire is used to drive the handrail, then the handrail can be driven with continuous contact, but bulges form on the driving wheel tire causing noise and wear

Engineering Contradiction:
Improvecontinuous contact driveVSAvoidbulge formation causing noise and wear
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the physical state of the filling medium from gas to liquid. The liquid-filled tire maintains continuous contact with the handrail for reliable driving while the liquid's incompressibility prevents bulge formation, eliminating noise and wear problems associated with gas-filled elastic tires

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite structure combining an elastic tire casing with liquid filling. The elastic material provides necessary deformation for continuous contact, while the liquid filling prevents bulge formation, creating a system that achieves both reliable continuous drive and eliminates harmful bulges

Inventive Principle:
Principle #40Composite materials

2Reliability

If the driving wheel tire is made highly elastic to prevent slip-stick effects, then static friction is maintained, but considerable wear and tear occur

Engineering Contradiction:
Improvestatic friction maintenanceVSAvoidwear and tear
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent changes the filling medium from gas to liquid, which modifies the tire's deformation characteristics. The liquid-filled tire maintains sufficient elasticity for static friction while reducing excessive deformation that causes wear, achieving a balance between friction maintenance and wear reduction

Inventive Principle:
Principle #35Parameter changes

3Reliability

If compressed gas is used to fill the driving wheel tire to maintain pressure contact, then the handrail is driven continuously, but noise development increases

Engineering Contradiction:
Improvecontinuous driveVSAvoidnoise development
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces gas filling with liquid filling. The liquid's incompressibility prevents the tire from over-deforming and creating bulges that generate noise, while maintaining continuous contact pressure for reliable continuous drive operation

Inventive Principle:
Principle #35Parameter changes

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

The solution reduces noise, wear, and energy consumption while enhancing driving comfort by preventing slip-stick effects and bulging, ensuring a continuous, jerk-free operation of the handrail.

Implementation Method 1

The driving wheel tire acts as a power transmission element in that its outer peripheral surface bears under pressure against the inner surface of the handrail

Methodology Applied
Scientific EffectHydrostatic pressure: Pressure Increase

Implementation Method 2

a body made of a solid material, which in itself, i.e. without, for example, the Acting upon by pressurized gas, is dimensionally stable, and which is also elastically well deformable

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 3

the handrail is driven by the static friction acting between the power transmission element and the handrail

Methodology Applied
Scientific EffectStatic friction: Static Friction

Data Source

PatentEP1739048B1Driving pulley for a flexible handrail
Publication Date: 2010.03.03 INVENTIO AG
  • EP1739048B1 patent drawingFigure 1~2
  • EP1739048B1 patent drawingFigure 3~4

AI summary

The wheel (10) has inner layer (20) adjacent to an inner circumferential surface of readily elastically deformable layer (30). The inner layer is stiffer than readily elastically deformable layer. An outer layer (40) is arranged adjacent to outer circumferential surface of the deformable layer and arranged to rest against the handrail under static friction. The adjacent layers are coupled to each other in non-rotating manner.