Two-Layer Railway Sleeper Pad Adhesive System

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Solution Overview

Problem

Existing sleeper pads for railway sleepers are costly and time-consuming to manufacture due to complex adhesive systems and require additional effort in the sleeper factory, with low liability and inefficient stress distribution on the ballast bed.

Innovation Solution

A two-layer sleeper pad system where a first layer with profile elements forms an adhesive system attached to a second layer, allowing separate manufacturing and handling, with the profile elements extending transversely to the sleeper's longitudinal direction and forming a positive connection with the concrete sleeper, enabling efficient and stable attachment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a complex adhesive system with undercuts, holes and gaps is pressed into soft concrete, then a form-fitting connection is created, but the manufacturing process becomes expensive and time-consuming

Engineering Contradiction:
Improveconnection reliabilityVSAvoidmanufacturing efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The adhesive system is segmented into discrete profile elements (stripes) that are arranged in a pattern across the sleeper pad surface. Each profile element contains simplified geometric features (protrusions and recesses) rather than complex three-dimensional undercuts, allowing for easier manufacturing while maintaining connection reliability through the distributed array of elements

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the geometric parameters of the adhesive system from complex undercuts and gaps to simplified protrusions and recesses with specific dimensional relationships. The profile elements have controlled height, width, and spacing parameters that optimize both the form-fitting connection and manufacturing efficiency

Inventive Principle:
Principle #35Parameter changes

2Reliability

If adhesive systems are pressed into still soft concrete, then a form-fitting connection is created, but additional effort is required in the sleeper factory

Engineering Contradiction:
Improveconnection reliabilityVSAvoidmanufacturing simplicity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

Instead of pressing complex adhesive systems into soft concrete, the invention inverts the approach by providing a pre-formed sleeper pad with integrated profile elements that create the adhesive system. The profile elements are formed as part of the pad manufacturing process, eliminating the need for additional operations in the sleeper factory while maintaining reliable connection through the protrusion-recess geometry

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

3Ease of operation

If a two-layer structure with separate manufacture is used, then handling is simplified, but additional attachment processes are required

Engineering Contradiction:
Improvehandling easeVSAvoidstructure complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The invention merges the attachment function into the sleeper pad structure itself by integrating profile elements directly into the pad material. The two-layer structure combines a flexible pad base with an adhesive system layer, where the adhesive layer is seamlessly integrated rather than being a separate component requiring additional attachment hardware or mechanisms

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3464726B1Under tie pad
Publication Date: 2019.09.18 SEMPERIT OESTERREICHISCH AMERIKANISCHE GUMMIWERKE AKTIENGESELLSCHAFT
  • EP3464726B1 patent drawingFigure 1a~1b
  • EP3464726B1 patent drawingFigure 2a~2b
  • EP3464726B1 patent drawingFigure 2c~3

AI summary

Disclosed is an under tie pad, in particular for a tie supported in a ballast bed, comprising a first layer (10) and a second layer (20), the first layer being disposed on top of or against the second layer, the first layer forming an adhesive system for arrangement or mounting on a tie.