Rail Vehicle Sliding Door Locking via Bowden Cable

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Solution Overview

Problem

The existing swivel door modules for rail vehicles inadequately secure the door wing in its closed position, leading to potential egress of small objects and compromised passenger safety and comfort due to pressure fluctuations and noise issues, while also restricting passage width with the use of a rotary column.

Innovation Solution

A swivel sliding door module utilizing a Bowden cable system with cover point locks, where the door wing is secured through a combination of cover point locks and overstream locks, decoupled by dampening elements to prevent sudden movements, and a door drive system that allows for efficient movement and locking mechanisms without the need for a rotary column, enhancing safety and passage width.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single over-center locking mechanism is used to secure the door leaf, then the structure is simple, but the door leaf is inadequately secured and can be pushed outwards even when closed

Engineering Contradiction:
Improvelocking mechanism structureVSAvoiddoor leaf securing
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The door module is divided into two separate door leaves, each with its own over-center locking mechanism. This segmentation allows independent locking of each leaf, ensuring that even if one leaf is pushed, the other remains securely locked, thereby improving overall reliability without significantly increasing structural complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each door leaf is equipped with its own dedicated locking mechanism positioned at optimal locations. The first over-center locking mechanism secures the first door leaf while the second mechanism secures the second door leaf, providing localized security where needed most rather than relying on a single centralized locking system.

Inventive Principle:
Principle #3Local quality

2Strength

If a pivot column is used to connect locking mechanisms, then the locking mechanism is robust, but the passage width is restricted

Engineering Contradiction:
Improvelocking mechanism robustnessVSAvoidpassage width
Core Design Contradiction:
StrengthVSLength of moving object

Solution Approach 1:

The traditional pivot column connecting the locking mechanisms is completely removed from the design. Instead, each over-center locking mechanism operates independently with its own pivot points and linkage, eliminating the space-consuming central pivot column and thereby increasing the usable passage width while maintaining locking robustness through the distributed locking architecture.

Inventive Principle:
Principle #2Taking out (Extraction)

3Volume of moving object

If over-center locking mechanisms are aligned on an axis, then the mechanism is compact, but dynamic influences can cause sudden door opening

Engineering Contradiction:
Improvelocking mechanism compactnessVSAvoiddoor closure stability
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The two over-center locking mechanisms are positioned asymmetrically at different locations on the door module rather than being aligned on the same axis. This asymmetric arrangement creates different dynamic characteristics for each locking mechanism, so that when subjected to vibrations or pressure fluctuations, they respond differently and are unlikely to both fail simultaneously, thereby improving reliability while maintaining compactness.

Inventive Principle:
Principle #4Asymmetry

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 ensures the door wing remains securely closed, preventing object egress and maintaining passenger safety and comfort by decoupling dynamic influences, and allows for increased passage width without the rotary column, thus enhancing overall safety and operational efficiency.

Implementation Method 1

the friction during the actuation of such a Bowden cable is low

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

the coupling between the first and second over-center locking mechanisms incorporates a damping element. This allows the two locking mechanisms to be decoupled with respect to their dynamic and vibration behavior

Methodology Applied
Scientific EffectDamping: Damping

Data Source

PatentEP2899089B2Sliding door module for a rail vehicle with a plurality of over-centre locks coupled with a bowden cable
Publication Date: 2022.10.12 KNORR BREMSE GMBH
  • EP2899089B2 patent drawingFigure 1~2
  • EP2899089B2 patent drawingFigure 3
  • EP2899089B2 patent drawingFigure 4

AI summary

A swing-sliding door module (101..107) for a rail vehicle is specified, comprising a door leaf (20..22) that can be moved in an opening direction and a sliding direction. Furthermore, the swing-sliding door module (101..107) includes a first and a second over-center locking mechanism (30..32, 40..42, 161, 162) acting in the opening direction of the door leaf (20..22), which are directly or indirectly coupled to each other via a Bowden cable (80..82).