Pantograph Friction Strip Elastic Interlocking Assembly

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing friction strips for rail vehicle pantographs face heating issues due to high electric currents, and previous solutions for incorporating metal inserts are either costly, complex, or lack reliability in assembly and thermal expansion compensation.

Innovation Solution

A friction strip design featuring carbon strips and a metal insert assembled using elastic interlocking means, such as deformable tongues and grooves, which allows for robust, efficient, and cost-effective assembly while ensuring good current passage and accommodating differential thermal expansions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If screws are used to assemble the metal insert to the electricity collector support, then the assembly is secure, but the assembly time increases and the manufacturing cost increases

Engineering Contradiction:
Improveassembly reliabilityVSAvoidassembly time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent replaces the screw-based mechanical fastening system with a press-fit system where the metal insert is directly pressed into the electricity collector support. This substitution eliminates the need for screws and screwing operations, thereby reducing assembly time while maintaining secure assembly through the press-fit connection and elastic deformation of the support material.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent extracts the screws from the assembly process, removing the fastening elements entirely. The metal insert is held in place through the press-fit connection and elastic deformation of the electricity collector support, eliminating the need for additional fastening components and operations.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If screws are used to assemble the metal insert to the electricity collector support, then the assembly is secure, but the manufacturing cost increases

Engineering Contradiction:
Improveassembly reliabilityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent extracts the screws and associated fastening components from the assembly, eliminating the need for purchasing, storing, and managing additional parts. This reduction in component count directly lowers manufacturing costs while maintaining assembly reliability through the press-fit connection.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the fastening function into the electricity collector support structure itself, where the support's elastic deformation provides the securing mechanism. This integration eliminates the need for separate fastening components, thereby reducing manufacturing cost.

Inventive Principle:
Principle #5Merging (Combining)

3Power

If the friction strip is designed to handle high electric currents, then the current collection capability is improved, but heating problems occur

Engineering Contradiction:
Improveelectric current capabilityVSAvoidheating
Core Design Contradiction:
PowerVSTemperature

Solution Approach 1:

The patent employs a composite structure combining the metal insert (high electrical conductivity) with the electricity collector support (elastic material). This composite design allows the metal insert to carry high electric currents while the support provides mechanical stability and thermal management, distributing the thermal load and reducing heating problems.

Inventive Principle:
Principle #40Composite materials

4Reliability

If the metal insert is tightly secured to the electricity collector support, then the electrical connection is improved, but the freedom of sliding for thermal expansion compensation is reduced

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidthermal expansion compensation
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies local quality by creating different zones within the electricity collector support: a localized press-fit zone that provides secure electrical connection, and surrounding elastic zones that provide freedom of sliding for thermal expansion compensation. This spatial differentiation of mechanical properties resolves the contradiction between secure connection and thermal adaptability.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent utilizes parameter changes in the elastic material's mechanical properties, where the material exhibits different degrees of rigidity and elasticity in different regions and under different loads. The press-fit connection provides localized rigidity for electrical contact, while the overall elastic structure maintains compliance for thermal expansion.

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 provides a quicker, less expensive assembly with improved current control and thermal expansion compensation, reducing heating issues and enhancing the overall reliability of the friction strip.

Implementation Method 1

the electricity collector support and/or the metal insert comprising elastic interlocking means cooperating with the metal insert and/or the electricity collector support, so as to assemble the metal insert to the support electric collector

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the metal insert, which is more conductive than the friction strip, for example carbon, deflects part of the electric current, so as to reduce the amount of electric current flowing through the friction strip and thus limit their heating

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3333007B1Pantograph wearing strip for railway vehicle
Publication Date: 2020.04.08 SNCF MOBILITES
  • EP3333007B1 patent drawingFigure 1~3
  • EP3333007B1 patent drawingFigure 4~7
  • EP3333007B1 patent drawingFigure 8~12

AI summary

The invention relates to a friction strip (10) for a railway vehicle pantograph, comprising: - a first and a second carbon strip (11, 12) extending parallel to a longitudinal extension direction and on either side of a longitudinal extension plane comprising said longitudinal extension direction, - a metallic insert (13) extending along the longitudinal extension direction in the longitudinal extension plane (Px) and provided between the first carbon strip and the second carbon strip, and - an electricity collector support (14) to which the first and second carbon strips and the metallic insert are assembled, the electricity collector support and/or the metallic insert comprising elastic interlocking means (18) cooperating with the metallic insert and/or the electricity collector support, so as to ensure the assembly of the metallic insert to the electricity collector support.