Under sleeper pad
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Solution Overview
Problem
Existing sleeper pads with cork granules for vibration damping and ballast protection lack sufficient elasticity and stability, and their production often involves costly materials.
Innovation Solution
Incorporating a cellular synthetic elastomer, such as polyurethane, into the elastic layer of sleeper pads with cork granules to enhance elasticity and stability, while utilizing waste cork products and including a connecting layer for attachment and a protective layer for ballast protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If cork granules are used in the elastic layer, then vibration damping is improved, but elasticity and stability are insufficient
Solution Approach 1:
The patent combines cork granules with at least one cellular synthetic elastomer to form a composite elastic layer. This composite structure integrates the vibration damping properties of cork with the elasticity and stability of synthetic elastomers, resolving the contradiction between vibration damping performance and structural stability.
2Reliability
If costly materials are used in the elastic layer, then performance is improved, but production cost increases
Solution Approach 1:
The patent specifies that the cellular synthetic elastomer should have a density of 0.1 g/cm³ to 0.5 g/cm³ and a compression set of less than 10%. By controlling these parameters, the invention achieves optimal performance while using cost-effective materials and production methods.
3Loss of energy
If the elastic layer has high elasticity for vibration damping, then vibration damping is improved, but stability decreases
Solution Approach 1:
The patent creates a heterogeneous elastic layer where cork granules and cellular synthetic elastomer are distributed with different local properties. The cork granules provide vibration damping in specific regions, while the cellular synthetic elastomer provides structural stability and elasticity in other regions, achieving both functions simultaneously through spatial distribution.
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 provides optimized elastic properties for effective vibration damping, stability, and cost-effective production, while ensuring ballast protection and improved transverse displacement resistance.
Implementation Method 1
An elastomer is a dimensionally stable but elastically deformable material that can be elastically deformed under tensile and/or compressive loads and then at least largely returns to its original deformed shape after the load has ended
Implementation Method 2
Sleeper pads are arranged or fastened to the underside of the track sleepers carrying the rails for vibration damping and ballast protection
Implementation Method 3
the cork grains of the cork granules have a relatively high rigidity or plasticity and thus essentially assume the supporting function in the elastic layer
Implementation Method 4
The word cellular means that the synthetic elastomer is a body with gas or air pockets
Implementation Method 5
The cellular synthetic elastomer could therefore also be described as a porous elastic plastic or one that has gas and/or air inclusions
Data Source
Figure 1~4
AI summary
The invention relates to an under sleeper pad (1) to be fastened to an underside (3) of a sleeper (4), on the opposite side from the tracks (2), wherein the under sleeper pad (1) has at least one elastic layer (5) having cork grains (6) of a cork granulate distributed throughout. In addition, the elastic layer (5) has at least one cellular synthetic elastomer (7).