Rail Vehicle Plunger Buffer with Bolt Stopper and Damping

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Solution Overview

Problem

Existing buffer systems for rail vehicles face challenges with high weight, production costs, and complex designs that lead to reduced service life due to sudden loading of stop components during deflection, requiring additional springs for damping and complex assembly processes.

Innovation Solution

A buffer system featuring a guide rod with a conical centering disc and intermediate piece that provides a stop mechanism, allowing for adjustable damping without additional springs, and a simplified locking mechanism using a locking bushing with a transverse slot and securing pieces to prevent guide rod rotation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a guide rod with head and stop is used to limit spring deflection, then the buffer structure is simplified, but the head and stop are suddenly loaded at the end of stroke reducing service life

Engineering Contradiction:
Improvebuffer structureVSAvoidservice life of stop components
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent applies beforehand cushioning by introducing a damping element (such as a rubber buffer or dashpot) between the guide rod head and the stop component. This damping element absorbs and dissipates the shock loads that occur when the spring reaches full deflection, preventing sudden impacts on the stop components and thereby extending their service life while maintaining the simplified buffer structure.

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

2Reliability

If additional springs are added to dampen return movement, then damping performance is improved, but device complexity and weight increase

Engineering Contradiction:
Improvedamping performanceVSAvoidnumber of spring components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the additional mechanical spring system with an alternative damping mechanism such as a viscous damper, friction-based damping element, or elastomeric material. This substitution maintains effective damping of the return movement while avoiding the increased complexity and weight associated with adding another spring pack to the buffer assembly.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If a complex locking mechanism with multiple components is used to prevent guide rod rotation, then locking reliability is improved, but assembly complexity and production costs increase

Engineering Contradiction:
Improvelocking reliabilityVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent merges the locking function with existing buffer components by integrating the anti-rotation feature directly into the guide rod or its mounting structure. For example, the guide rod may be provided with a non-circular cross-section (such as a D-shape or hexagon) that prevents rotation within its bearing, or the locking function is combined with the stop component itself. This integration maintains locking reliability while significantly simplifying the assembly process and reducing production costs.

Inventive Principle:
Principle #5Merging (Combining)

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 design enhances the service life of buffer components by eliminating shock loads on stop elements and reducing the overall weight and complexity, while maintaining effective damping and secure locking without additional components.

Implementation Method 1

In the inner part of the housing there is a spring element to dampen the movement of the ram

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

A spring assembly is mounted on this guide rod, which cushions the ram under pressure

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

elastomer springs have been increasingly used in buffers for several years

Methodology Applied
Scientific EffectViscoelasticity: Viscoelasticity

Data Source

PatentEP2460709B1Plunger buffer for rail vehicles with bolt stopper
Publication Date: 2016.03.09 SMW SPEZIALMASCHEN & WERKZEUGBAU
  • EP2460709B1 patent drawingFigure 1
  • EP2460709B1 patent drawingFigure 2~6

AI summary

The sleeve buffer has a bolt stop and two cylindrical housing parts guided into each other. A stopping bush (8) has a central bore for a guide bar (1), a rearward clearance for a head (10) and a transverse slot for channeling the head of the guide bar. The guide bar is flattened on the both sides and the transverse slot is filled by multiple safety lugs (9) including the free depths of the stopping bushing after insertion and rotation of the head.