Conductor Rail Facing Cap Welding Inversion

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Solution Overview

Problem

Existing conductor rail designs face manufacturing challenges and reduced lifespan due to complex attachment methods and unfavorable welding locations, which compromise the accuracy of the facing cap and electrical contact.

Innovation Solution

A conductor rail design featuring a stainless steel facing cap with lateral portions of J-shape that are welded to the aluminum main body using longitudinal grooves, allowing for easy and reliable manufacturing and improved electrical contact through controlled welding and clamping, with the facing cap being made of ferritic stainless steel for enhanced wear and corrosion resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the facing cap is attached using complex welding methods below the head portion, then the attachment is secure, but the manufacturing becomes difficult and requires unfavorable welding positions

Engineering Contradiction:
Improveattachment reliabilityVSAvoidmanufacturing ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent inverts the conventional welding approach by moving the welding location from below the head portion to above the head portion. The facing cap is welded to the head portion at its top surface, which is the opposite of traditional methods. This inversion allows welders to access the welding area from above, eliminating the need to position the rail upside down or perform welding in confined spaces below the head, thereby significantly improving manufacturing ease while maintaining secure attachment.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent introduces a dimensional change by utilizing the vertical space above the head portion for welding operations. Instead of welding horizontally or from below, the design enables vertical welding access from the top, creating a new operational dimension that simplifies the manufacturing process while ensuring reliable attachment of the facing cap to the head portion.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If the facing cap uses complex attachment methods with multiple components, then the attachment is secure, but the manufacturing precision requirements increase

Engineering Contradiction:
Improveattachment reliabilityVSAvoidfacing surface tolerance
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The facing cap is divided into two functional segments: a central portion that contacts the head portion and provides electrical conduction, and lateral portions that extend downward to be welded to the head portion. This segmentation allows the central portion to be optimized for electrical contact with relaxed tolerance requirements, while the lateral portions serve as dedicated attachment elements. The separation of contact function from attachment function reduces the overall manufacturing precision requirements while maintaining secure attachment.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The lateral portions of the facing cap act as intermediary elements between the central portion and the head portion. These intermediaries provide a dedicated welding interface that is separate from the electrical contact surface, allowing the central portion to focus on electrical conductivity without bearing the full burden of attachment precision requirements. The intermediaries absorb some of the precision demands, making the overall assembly more manufacturable.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If welding is performed below the head portion, then the facing cap is securely attached, but the welding process becomes complex and time-consuming

Engineering Contradiction:
Improveattachment reliabilityVSAvoidwelding time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent inverts the conventional welding approach by moving the welding location from below the head portion to above the head portion. The facing cap is welded to the head portion at its top surface, which is the opposite of traditional methods. This inversion allows welders to access the welding area from above, eliminating the need to position the rail upside down or perform welding in confined spaces below the head, thereby significantly reducing welding time and simplifying the manufacturing process while maintaining secure attachment.

Inventive Principle:
Principle #13The other way round (Inversion)

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 simplifies the manufacturing of the facing cap, ensures a tight and durable electrical contact, and extends the lifespan of the contact shoe by allowing for efficient welding above the head portion, maintaining high conductivity and mechanical resistance.

Implementation Method 1

The facing cap includes two welding seams which are provided in two gaps extending between the lateral edge 402 and an end 420a of the straight section 420 on the first hand, and between the lateral edge 404 and an end 440a of the straight section 440

Methodology Applied
Scientific EffectWelding: Welding

Implementation Method 2

The curved portions 422 and 442 are inserted in the longitudinal grooves 26. The grooves 26 have an open side oriented towards the lower side of the main body 2 and away from the central longitudinal plane P2

Methodology Applied
Scientific EffectMechanical interlocking: Mechanical Fastener

Implementation Method 3

a contact shoe which slides against the top surface of the facing cap

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 4

The central portion 40 is adapted to lay against the top surface 240 of the head portion 24 in a tight contact allowing maximal electrical conduction

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3072731B1Conductor rail for transmitting electric energy to a train
Publication Date: 2022.05.04 ALSTOM TRANSPORT TECH SAS
  • EP3072731B1 patent drawingFigure 1~2
  • EP3072731B1 patent drawingFigure 3

AI summary

This conductor rail (R) for transmitting electric energy to a train comprises a main body (2) made of high conductivity aluminum alloy, including a head portion (24), a stem portion (22) and a base portion (20) and a facing cap (4) made of stainless steel, on which a conductive shoe is adapted to slide. The facing cap (4) comprises a central portion (40) adapted to lay against a top surface (240) of the head portion (24) and two lateral portions (42, 44) arranged on lateral sides (242, 244) of the head portion (24) and welded to the central portion (40) so that the facing cap (4) is secured to the main body (2). The lateral edges (402, 404) of the central portion (40) extend in the alignment of the lateral sides (242, 244) of the head portion (24).