Tram Rail Insulation Splint Design for Sealing and Vibration Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing insulation and sealing devices for tramway rails fail to provide perfect sealing and insulation, leading to vibration and sound wave propagation, stray current issues causing corrosion, increased installation time and cost due to numerous site cuts, and aesthetic irregularities.

Innovation Solution

The proposed solution involves a device with a lower splint that perfectly envelops the rail base, eliminating hard points and using long side splints to cover both lower splints and protective covers, reducing site cuts, and incorporating notches for easy fitting and post-installation expansion joint preparation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional lip fishplates are used with lips passing under the rail base, then the device structure is simple, but sealing and insulation are imperfect allowing concrete infiltration and stray current passage

Engineering Contradiction:
Improvesealing and insulation qualityVSAvoiddevice structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The device is divided into multiple functional components: lower splints for base insulation, upper splints for flange insulation, and lateral splints for side sealing. Each segment performs a specific sealing function, collectively achieving complete rail isolation while maintaining manageable structural complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The splints are arranged in a nested configuration where lower splints fit against the rail base, upper splints fit against the flanges, and lateral splints fill the gaps between them. This nested arrangement maximizes sealing effectiveness while minimizing the overall device footprint

Inventive Principle:
Principle #7Nested doll (Nesting)

2Manufacturing precision

If multiple separate splints are used for lower and cover sections, then each part can be precisely fitted, but the number of site cuts increases significantly

Engineering Contradiction:
Improvefitting precisionVSAvoidinstallation speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The lateral splints are designed as multi-functional elements that simultaneously seal between the finishing coating and rail, connect lower and upper splints, and provide structural support. This reduces the total number of separate components requiring precise fitting and cutting

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The lower and upper splints are combined into a single continuous insulating element that wraps around the rail, eliminating the need for separate installation and reducing the number of joints requiring precise alignment and cutting

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If the cavity for expansion joint is not pre-prepared, then installation is faster, but the cavity requires cleaning just before sealing which increases time and cost

Engineering Contradiction:
Improveinstallation speedVSAvoidcavity cleaning time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The splint configuration is designed to automatically create a pre-cleaned, regular-shaped cavity during installation. The splints themselves form the cavity boundaries, eliminating the need for separate cleaning operations before sealant application

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The installation process itself creates the prepared cavity condition. As the splints are positioned and secured, they automatically define and prepare the cavity space, making the cavity ready for sealing without additional cleaning steps

Inventive Principle:
Principle #25Self-service

4Ease of operation

If lips are loosely connected under the rail base, then installation is easier, but hard points form eliminating rail movement and propagating vibrations

Engineering Contradiction:
Improveinstallation easeVSAvoidvibration propagation
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The lower splint is made of flexible material that can deform to accommodate rail movement while maintaining continuous contact and sealing. This flexibility prevents hard point formation and vibration propagation while keeping installation straightforward

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The insulating device is designed with dynamic characteristics that allow it to adapt to rail movement during tram passage. The flexible splints can deform and recover, maintaining sealing effectiveness while accommodating the dynamic behavior of the rail system

Inventive Principle:
Principle #15Dynamics

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

This solution ensures perfect insulation and sealing, preventing vibration and corrosion, reducing installation time and cost, and maintaining aesthetic regularity by eliminating the need for pre-cleaning and minimizing site cuts.

Implementation Method 1

a lower splint (11) intended to envelop the base (8) of the rail (3) and to extend between two adjacent crosspieces (2)

Methodology Applied
Scientific EffectPhysical Containment: Physical Containment

Implementation Method 2

each side splint (22, 23) made of waterproof material... intended to cover, respectively, on each side of the rail (3), at least one lower splint (11) and a protective cover (4)

Methodology Applied
Scientific EffectWaterproof sealing:

Implementation Method 3

the lower splint (11) comprises, on its face facing the rail (3), longitudinal notches making it possible to enlarge the opening of the housing intended to receive the base (8) of the rail (3)

Methodology Applied
Scientific EffectMechanical expansion:

Implementation Method 4

the rail, wrapped at its base in a flexible material, is free of any movement. Thus, there is no propagation of vibrations or sound waves

Methodology Applied
Scientific EffectVibration absorption: Damping

Implementation Method 5

given that the upper profile of the wings of the lower splint corresponds to the upper profile of the protective covers, the lateral splints can cover both a lower splint and a protective cover... the rail is perfectly isolated from its external environment

Methodology Applied
Scientific EffectElectrical insulation: Electrical Resistance

Data Source

PatentEP1916336B1Isolierungs- und Versiegelungsvorrichtung für ein auf Schwellen montiertes Gleis, insbesondere für eine Strassenbahn-Gleiskonstruktion
Publication Date: 2016.12.07 PLASTIFORMS
  • EP1916336B1 patent drawingFigure 1~3
  • EP1916336B1 patent drawingFigure 4~8
  • EP1916336B1 patent drawingFigure 6~7

AI summary

The device has a flexible and sealed lower rail splice including length corresponding to a distance between two sleepers. A tie plate (12) and two vertical flanges (13, 14) define a housing that receives a base (8) of a tramway type rail (3). The housing has a shape complementary to that of the base. Two lateral rail splices (22, 23) include lower profiles which are respectively arranged at each side of the rail and which are complementary of an upper profile of the lower rail splice and complementary of an upper profile of protective housing covers.