Rail Vehicle Door Locking Mechanism Prevents Premature Bolt Actuation

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Solution Overview

Problem

Existing locking devices for rail vehicle doors face malfunctions due to independent operation of the locking tongue and latch bolt, leading to deformation and failure, especially under dynamic operating conditions where closing force and speed cannot be restricted, and seals cause the door to spring back during closure.

Innovation Solution

A locking device where the locking tongue and trigger are functionally dependent, allowing the pressing device to be unlocked only when the locking tongue engages in the latch, ensuring the bolt is inserted into a sloping edge opening in the door frame, preventing premature actuation and ensuring proper sealing and operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the locking bolt is made independently operable, then the door can be locked quickly, but the locking mechanism may malfunction due to premature actuation before the striker engages the latch

Engineering Contradiction:
Improvedoor locking speedVSAvoidlocking mechanism reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary action by ensuring the striker engages the latch before the locking bolt is permitted to extend. The mechanism is designed so that the latch engagement must occur first, which then enables the bolt actuation through the relative movement between trigger and locking tongue. This prevents premature bolt extension that would cause malfunction.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary relationship between the trigger and locking tongue components. The trigger must move relative to the locking tongue as the striker engages the latch, and this relative movement serves as the intermediary mechanism that permits subsequent bolt actuation. This intermediary action ensures proper sequencing and prevents direct premature bolt extension.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If the door closing force is increased to overcome seal spring-back, then the door seals properly, but the locking bolt may hit the door frame and prevent easy closing

Engineering Contradiction:
Improvedoor sealing precisionVSAvoiddoor closing ease
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The patent applies preliminary action by retracting the locking bolt before the door closing process begins. The bolt is held in a retracted position until the door is properly closed and the striker engages the latch, at which point the bolt is permitted to extend. This prevents the bolt from interfering with the door frame during closing while ensuring proper sealing force is applied.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If the locking bolt is extended when the door is open, then the lock is prepared, but the bolt hits the door frame during closing and prevents proper door closure

Engineering Contradiction:
Improvelocking preparation speedVSAvoiddoor closure ease
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The patent applies dynamics by making the locking bolt position dynamic rather than static. The bolt is retracted during door opening and closing operations, then extends automatically when the door is properly closed and the striker engages the latch. This dynamic positioning ensures the bolt does not interfere with door movement while maintaining locking readiness.

Inventive Principle:
Principle #15Dynamics

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 solution ensures reliable pressure-tight locking and unlocking of rail vehicle doors by linking the trigger's function to the locking tongue's engagement, preventing malfunctions and maintaining door closure under dynamic conditions, enhancing operational reliability and safety.

Implementation Method 1

the installed seals cause the door to spring back, which must be overcome

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2559834B1Closing device for vehicle doors
Publication Date: 2020.01.01 BOMBARDIER TRANSPORTATION GMBH
  • EP2559834B1 patent drawingFigure 1a~1b
  • EP2559834B1 patent drawingFigure 1c~2
  • EP2559834B1 patent drawingFigure 3

AI summary

The device (7) has locking tab (1) which is inserted into first opening (A) formed at door frame. A latch (11) of the pressing device (2) is introduced into second opening (B) on frame, such that door leaf is pressed by movement of bolt of pressing device along inclined edge against frame. A trigger (4) is movable during insertion of locking tongue into first opening relative to locking tongue, and is in cooperation with locking tongue, for transfer of pressing device from locked state into unlocked state, so that bolt is inserted in second opening.