Rail Anchoring Device with Spring Element for Ballastless Track Repair

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Solution Overview

Problem

Existing methods for repairing damaged rail sections in ballastless tram tracks are labor-intensive, costly, and do not provide long-term stability due to recurring thermal and mechanical loads, leading to potential loosening and safety issues.

Innovation Solution

A device comprising a receiving channel, anchor element, grouting compound, tensioning element, and spring element is used to securely fasten the rail by drilling into the subsoil, introducing a grouting compound to fill cavities, and employing a spring element to prestress the rail, preventing loosening and allowing for thermal expansion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of repair

If the rail is repaired by cutting out and removing the damaged section, then the damaged section can be replaced, but the repair requires considerable effort and results in long downtimes

Engineering Contradiction:
Improverepair effortVSAvoidrail section downtime
Core Design Contradiction:
Ease of repairVSLoss of time

Solution Approach 1:

The invention extracts only the necessary anchoring function from the traditional repair method. Instead of removing the entire damaged rail section, an anchor element is inserted through a receiving channel into the loosened substructure to provide localized stabilization. This selective extraction of the anchoring function enables rapid repair without the need to cut out and remove large sections of the rail, thereby reducing both repair effort and downtime.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The repair system is segmented into modular components: a receiving channel, an anchor element, a grouting compound, a tensioning element, and a spring element. This segmentation allows each component to perform its specific function independently and enables the repair to be carried out quickly by assembling these pre-fabricated parts rather than performing complex removal and replacement operations.

Inventive Principle:
Principle #1Segmentation

2Ease of manufacture

If the rail is connected to the subsoil using adhesive only, then the connection is simple, but the rail can shake loose again due to thermal and overrun loads

Engineering Contradiction:
Improveconnection simplicityVSAvoidlong-term stability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The invention creates a composite anchoring system that combines multiple materials and mechanisms: the anchor element (metal), the grouting compound (cementitious or epoxy material), the tensioning element (steel rod or cable), and the spring element (elastic material). This composite structure provides both the simplicity of a unified anchoring solution and the long-term reliability needed to resist thermal expansion and mechanical overrun loads, overcoming the limitations of adhesive-only connections.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The spring element introduces dynamic characteristics to the anchoring system, allowing it to accommodate thermal expansion and contraction of the rail while maintaining constant contact pressure. The spring can compress and extend dynamically in response to thermal and mechanical loads, preventing the rail from shaking loose while preserving the simplicity of the anchoring installation.

Inventive Principle:
Principle #15Dynamics

3Reliability

If the receiving channel penetrates deep into the solid subsoil, then the anchor element is securely fixed, but the installation becomes more complex

Engineering Contradiction:
Improveanchor element fixationVSAvoidinstallation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The receiving channel is designed to be inserted through the base flange of the rail and into the loosened substructure, with the anchor element nested within the receiving channel. The tensioning element and spring element are then nested onto the anchor element. This nested arrangement allows deep penetration into the solid subsoil for reliable fixation while keeping the installation process organized and manageable, reducing overall complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The receiving channel is pre-formed and prepared before insertion, with its geometry and dimensions optimized for the intended anchor element. This preliminary preparation of the receiving channel allows for straightforward insertion and anchoring operations, reducing installation complexity while ensuring that the anchor element achieves secure fixation at the required depth in the solid subsoil.

Inventive Principle:
Principle #10Preliminary action

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 enables a fast, cost-effective, and permanent repair of damaged rail sections, enhancing stability and preventing re-loosening under thermal and mechanical loads, while allowing for thermal expansion without compromising safety.

Implementation Method 1

the spring element (5) and, in particular, a tensioning element (4) arranged on the anchor element (3) in such a way that the spring element (5) can be prestressed in the axial direction of the anchor element (3) by an axial displacement of the tensioning element (4) in the direction of the base flange (6)

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

A grouting compound can be introduced via this annular space. The grouting compound penetrates both the annular space and the cavities, fills them and seals them. After the grouting compound has hardened, it fixes the anchor element in its position

Methodology Applied
Scientific EffectHardening:

Data Source

PatentEP2626467B1Device and method for the subsequent fixing of a rail in a ballastless location
Publication Date: 2017.05.24 BENNERT INGENIEURBAU GMBH
  • EP2626467B1 patent drawingFigure 1
  • EP2626467B1 patent drawingFigure 2
  • EP2626467B1 patent drawingFigure 3

AI summary

The device has an anchoring element i.e. threaded bolt, received by a receiving channel. A grouting mass is provided and hardened in an annular chamber between the anchoring element and the receiving channel and in a hollow chamber (10) between a loosened section (7) and a fixed section (8) of a substrate. A clamping element is arranged above a foot flange (6) of a track (1) on an upper end of the anchoring element and a spring element i.e. cup spring. The spring element is clamped in a direction of the foot flange by axial position alteration of the track.