Rail Vehicle Coupler With Nested Reversible and Non-Reversible Buffers

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Solution Overview

Problem

Existing coupler designs for rail vehicles face issues with compactness, wear of elastomeric components, and ineffective attenuation of high-frequency forces, leading to potential damage during impacts and limited space for additional equipment.

Innovation Solution

A coupler with a buffer column that includes both reversible and non-reversible buffers, where the non-reversible buffer is a plastically deformable hollow tube encircling a reversible buffer, allowing for compact and effective energy absorption and reduced risk of damage from high-frequency forces, with all components positioned externally for easy inspection and maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a buffer element is fixed in the coupler element to form part of it, then bi-directional energy absorption is achieved, but the coupler element length increases significantly

Engineering Contradiction:
Improveenergy absorption capabilityVSAvoidcoupler element length
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The buffer element is received within a cavity in the coupler element, with the buffer column extending through the coupler element. This nesting arrangement allows the buffer to be integrated into the coupler structure without significantly increasing the overall length, as the buffer occupies internal space rather than extending externally.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

Instead of extending the buffer in the longitudinal direction (series connection), the buffer is positioned transversely within the coupler element structure. The buffer column extends through the coupler element in a direction that utilizes the transverse dimension, allowing energy absorption functionality without increasing the longitudinal length of the coupler assembly.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If the coupler accommodates track curves and undulations, then flexibility is improved, but compressive forces become mis-aligned with the longitudinal axis increasing damage risk

Engineering Contradiction:
Improveaccommodation of track variationsVSAvoidmis-aligned compressive forces
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The buffer element is pre-positioned within the coupler element cavity to provide cushioning before mis-aligned forces can cause damage. The elastomeric buffer material is already in place to absorb and redistribute compressive forces that may become mis-aligned during operation on curved or undulating tracks.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The buffer element is made of elastomeric material that combines flexibility with shock-absorbing properties. This composite material approach allows the buffer to accommodate mis-aligned forces through elastic deformation while dissipating energy, reducing the risk of damage to rigid coupler components.

Inventive Principle:
Principle #40Composite materials

3Volume of moving object

If elastomeric elements are combined into the space between gimbals for compactness, then space efficiency is improved, but wear of elastomeric components occurs

Engineering Contradiction:
Improvecoupler volumeVSAvoidelastomeric component durability
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The buffer element is extracted from the internal space between gimbals and repositioned within the coupler element cavity. This extraction removes the elastomeric component from the high-wear region between gimbals while maintaining compact overall dimensions, as the buffer fits within the existing coupler element volume.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The buffer element serves as an intermediary between the coupler element and the buffer column. This intermediary position allows the elastomeric buffer to absorb forces before they reach critical components, protecting against wear while maintaining a compact arrangement where the buffer is integrated into the coupler structure rather than occupying space between gimbals.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 a compact, effective energy absorption system that reduces the risk of damage from high-frequency impacts and minimizes space requirements within the vehicle, allowing for additional equipment and easier maintenance, while ensuring continued articulation of coupled vehicles post-impact.

Implementation Method 1

a reversible buffer that attenuates buff and draft forces acting between the free end and the mounting

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a non-reversible buffer that attenuates buff forces acting between the free end and the mounting and attaining or exceeding a predetermined energy threshold

Methodology Applied
Scientific EffectPlasticity: Plasticity

Data Source

PatentEP2851260B1A coupler
Publication Date: 2020.05.20 T A SAVERY
  • EP2851260B1 patent drawingFigure 1
  • EP2851260B1 patent drawingFigure 2
  • EP2851260B1 patent drawingFigure 3

AI summary

A coupler (10) comprises at least a first gimbal (31; 32) defining a pivot that is secured to a mounting (41) for securing to a frame member of a vehicle, the pivot also being secured to a buffer column (39) part of which protrudes on an opposite side of the pivot to the mounting (41) such that the buffer column (39) is moveable relative to the mounting (41) with at least two degrees of freedom. The buffer column (39) defines a free (42) end that is remote from the mounting (41) and that is securable to a further member. The buffer column (39) also includes both a reversible buffer that attenuates buff and draft forces acting between the free end (42) and the mounting (41) and also a non-reversible buffer that attenuates buff forces acting between the free end (42) and the mounting (41) and attaining or exceeding a predetermined energy threshold, the reversible and non-reversible buffers overlapping over at least part of their lengths in the buffer column (39) which in turn overlaps at least one of the pivots..