Railway Door Manual Unlocking with Force Accumulation Locking

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Solution Overview

Problem

Existing manual door unlocking devices for railway vehicles risk damage when passengers apply excessive force during emergency operations, and there is a risk of the door being unlocked while the vehicle is in motion.

Innovation Solution

A manual door unlocking device with a force accumulating portion that absorbs and accumulates operating force, a restraining portion to control force transmission, and an unlocking portion synchronized by a piston and cylinder mechanism, ensuring safe and controlled unlocking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the actuator locks the lever to prevent unauthorized opening during vehicle travel, then door security is improved, but the unlocking mechanism becomes vulnerable to damage from excessive operating force

Engineering Contradiction:
Improvedoor securityVSAvoidunlocking mechanism durability
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The force accumulating portion accumulates operating force beforehand through spring deformation, cushioning the impact of excessive force on the unlocking mechanism. When the lever is operated, the spring absorbs the initial force buildup and releases it in a controlled manner, preventing direct transmission of excessive force to the actuator and unlocking components.

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

Solution Approach 2:

The force accumulating portion acts as an intermediary between the lever operation and the unlocking mechanism. It mediates the force transmission by accumulating and regulating the operating force, ensuring that the unlocking mechanism receives controlled force rather than direct excessive force from lever operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the lever is made operable to allow manual unlocking, then emergency evacuation capability is improved, but the risk of accidental unlocking during vehicle travel increases

Engineering Contradiction:
Improveemergency evacuation capabilityVSAvoiddoor locking reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The force accumulating portion performs preliminary action by accumulating operating force through spring deformation before actual unlocking occurs. This preliminary force accumulation requires a specific operation sequence and force threshold, ensuring that casual or accidental operations during vehicle travel cannot trigger unlocking, while genuine emergency operations can accumulate sufficient force to unlock.

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If the unlocking mechanism is designed to be simple and direct, then ease of operation is improved, but the mechanism becomes susceptible to damage from excessive force

Engineering Contradiction:
Improvelever operation simplicityVSAvoidunlocking mechanism durability
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The force accumulating portion is nested within the unlocking mechanism structure, with the spring and restraining portion integrated into the existing lever and actuator system. This nested design adds the force accumulation function without requiring a completely separate external mechanism, maintaining relative simplicity while providing protection against excessive force.

Inventive Principle:
Principle #7Nested doll (Nesting)

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

Prevents damage to the unlocking mechanism by absorbing excessive force and allows safe unlocking of railway vehicle doors during emergencies, even when operated with large forces, while ensuring the door remains locked during travel.

Implementation Method 1

a rod (3) disposed coaxially in the cylinder (202), the rod (203) further extending toward the negative X direction, the portion of the interior of the cylinder (202) positioned on the positive X direction side relative to the end portion of the cylinder (202) in the negative X direction coaxially containing a spring (268)

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The unlocking portion further includes a spring (253) for returning the large-diameter portion (252) and the spring (268) of the force accumulating portion to positions they were in before accumulation of the operating force

Methodology Applied
Scientific EffectElastic recovery: Elasticity

Data Source

PatentEP4001557B1Manual door unlocking device and railway vehicle door device
Publication Date: 2025.12.03 NABTESCO CORP
  • EP4001557B1 patent drawingFigure 1
  • EP4001557B1 patent drawingFigure 2
  • EP4001557B1 patent drawingFigure 3

AI summary

A manual door unlocking device (100) according to one aspect of the present invention includes: a locking mechanism (110) for locking a door leaf (10) when the door leaf (10) is at a fully closed position, the door leaf (10) being configured to move by a driving force from a drive source to open and close a doorway (105) of a railway vehicle; an operation portion (120) configured to receive manual operation; a force accumulating portion (130) for accumulating a predetermined amount of operating force produced by the manual operation; and an unlocking portion (150) configured to transmit the predetermined amount of operating force accumulated in the force accumulating portion (130) to undo the locking mechanism (110).