Insulating Tie-Plate Ring for Rail Fastening

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Solution Overview

Problem

Conventional rail fastening systems face challenges in achieving reliable electrical insulation between conductive rails and the subsurface, leading to electrical bridges due to misalignment and moisture ingress through the through-openings of plate elements.

Innovation Solution

Incorporating an elastically yielding ring element within the through-opening of the plate element, which forms a barrier to prevent moisture and electrical contact, ensuring a secure seal even with imperfect alignment and enhancing the sealing effectiveness by being flexible in both axial and circumferential directions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a through-opening is provided in the plate element for fastening purposes, then the fastening function is improved, but electrical insulation between the rail and subsurface deteriorates due to potential moisture ingress and conductive bridges

Engineering Contradiction:
Improvefastening functionVSAvoidelectrical insulation
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

An elastic ring element is introduced as an intermediary component between the conductive plate element and the subsurface. This ring acts as a mediator that allows the fastening function to proceed while blocking the harmful conductive path. The ring element is positioned at the through-opening and creates an electrical barrier between the plate and subsurface, preventing moisture and conductive bridges while maintaining mechanical fastening capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

A flexible elastic ring element is used to seal the through-opening area. The ring's elasticity allows it to deform and conform to the interface between the plate element and subsurface, creating a reliable seal that prevents moisture ingress and electrical conduction. The flexible nature of the ring enables it to accommodate manufacturing tolerances and alignment variations while maintaining the electrical insulation function.

Inventive Principle:
Principle #30Flexible shells and thin films

2Reliability

If perfect alignment between the dowel and plate element is required for optimal sealing, then electrical insulation is improved, but manufacturing precision and assembly reliability deteriorate due to the difficulty of achieving perfect alignment in practice

Engineering Contradiction:
Improveelectrical insulationVSAvoidalignment precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The elastic ring element changes its physical parameters (shape, volume, density) in response to compression forces during assembly. When the plate element is placed on the subsurface, the ring is compressed between these surfaces, causing it to deform and conform to the actual interface geometry. This parameter change allows the seal to adapt to alignment variations without requiring perfect initial positioning, maintaining electrical insulation despite manufacturing tolerances.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The elastic ring introduces dynamic adaptability to the otherwise static fastening system. Rather than relying on fixed, precise alignment, the ring dynamically adjusts its position and shape to accommodate misalignment. The elastic deformation allows the sealing interface to self-adjust during assembly, transforming a rigid alignment requirement into a flexible, tolerance-friendly design.

Inventive Principle:
Principle #15Dynamics

3Reliability

If the elastic ring element is compressed between the plate element and subsurface, then electrical insulation is improved, but the contact pressure between components increases

Engineering Contradiction:
Improveelectrical insulationVSAvoidcontact pressure
Core Design Contradiction:
ReliabilityVSStress or pressure

Solution Approach 1:

The elastic ring distributes the contact pressure over a larger area and in a more uniform manner compared to direct rigid contact. The flexible nature of the ring allows it to conform to the surface irregularities, spreading the compressive forces across the entire contact interface rather than concentrating them at discrete points. This reduces peak stresses while maintaining the necessary compression for electrical insulation.

Inventive Principle:
Principle #30Flexible shells and thin films

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 effectively prevents moisture and electrical contact between the substrate and the fastening element, ensuring reliable electrical insulation and secure sealing, even under unfavorable conditions, thereby reducing the occurrence of electrical bridges.

Implementation Method 1

a ring element made of an elastically yielding material sits in the mouth of the through-opening assigned to the substrate

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3047070B1Electrically isolating tie-plate for fastening rails
Publication Date: 2018.10.31 VOSSLOH WERKE GMBH
  • EP3047070B1 patent drawingFigure 1
  • EP3047070B1 patent drawingFigure 2
  • EP3047070B1 patent drawingFigure 3

AI summary

The present invention relates to a plate element for a fastening point at which a rail (S) which is provided for rail vehicles is fastened to a fixed substrate (11), wherein the plate element (1) has a passage opening (4, 5) which leads from the top face (3) of said plate element, which top face is associated with the rail (S) which is to be fastened, to the lower face (2) of said plate element, said lower face being associated with the substrate (11), through which passage opening a fastening element (14, 15) for fastening the plate element (1) on the substrate (11) is guided during use, said fastening element engaging in a dowel (12, 13) which is inserted into the substrate (11), and also a fastening point in which a rail for a rail vehicle is fastened on a fixed substrate. The plate element according to the invention allows a rail for a rail vehicle to be fastened to a fixed substrate and in this way also ensures optimum electrical insulation in unfavourable use conditions. This is achieved by a ring element (8a, 8b; 20) which is composed of an elastically flexible material being seated in the region (6) of the mouth of the passage opening (4, 5) which is associated with the substrate (11).