Vehicle Door Latch Release Device with Dual Spring Rotary Lever

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing vehicle door latch release devices lack differentiation in operation loads between normal and emergency operations, leading to potential unnecessary emergency operations during normal use.

Innovation Solution

A latch release device with a rotary lever and dual spring mechanism, where the operation member is urged by a first spring for normal operation and by both first and second springs for emergency operation, creating a distinct difference in operation loads.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the spring force of the second spring is set to be extremely small, then the switch contact can be held at the contact position during normal operation, but the operation load difference between normal and emergency operations becomes insufficient

Engineering Contradiction:
Improveswitch contact stabilityVSAvoidoperation load differentiation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The operation range is segmented into two distinct phases: normal operation (first operation position) and emergency operation (second operation position). The rotary lever mechanism segments the force transmission path, allowing the first spring to handle normal operations independently while the second spring engages only during emergency operations, creating clear operational differentiation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically transitions between different spring configurations based on operation depth. During normal operation, only the first spring is active. During emergency operation, the rotary lever rotates to engage the second spring, dynamically changing the force characteristics to provide clear feedback and prevent accidental activation.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If the open button is pressed in more than the predetermined stroke during normal operation, then emergency operation mechanism is activated, but unnecessary emergency operations may occur

Engineering Contradiction:
Improvelatch release functionalityVSAvoidoperation accuracy
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The rotary lever acts as an intermediary mechanism between the operation member and the latch release operation force transmitting means. It provides a mechanical transition zone that requires deliberate additional force to activate, serving as a mediator that prevents accidental emergency activation while still allowing intentional emergency operations when needed.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If a single spring mechanism is used, then the device structure is simple, but the operation load differentiation between normal and emergency operations cannot be achieved

Engineering Contradiction:
Improvespring mechanism structureVSAvoidoperation load distinction
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The patent merges two spring mechanisms (first spring and second spring) with a rotary lever into a unified system. The first spring provides baseline operation force, while the second spring provides additional resistance during emergency operations. The rotary lever merges these two spring forces in a controlled manner, achieving operation load differentiation without excessive structural complexity.

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

Enhances operability by clearly distinguishing normal from emergency operations, preventing unnecessary emergency actions during normal use and ensuring a clear difference in operation loads.

Implementation Method 1

a first spring that urges the operation member to a non-operation position side

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 2

a second spring that directly urges the rotary lever to a non-rotation position side

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP2511452B1Latch release device for vehicle door
Publication Date: 2019.04.24 HONDA LOCK MFG CO LTD
  • EP2511452B1 patent drawingFigure 1
  • EP2511452B1 patent drawingFigure 2
  • EP2511452B1 patent drawingFigure 3

AI summary

A latch release device for a vehicle door includes: an operation member (24); a first spring (25) that urges the operation member (24) to a non-operation position side; a switch (26) that is connected to an electric actuator (50) so as to be made electrically continuous in response to an operation of the operation member (24) from the non-operation position to a first operation position; and latch release operation force transmitting means (56) that mechanically transmits a latch release operation force to a latch device (19) in response to an operation of the operation member (24) to a second operation position. In the latch release device, a rotary lever (27) that constitutes part of the latch release operation force transmitting means (56) to rotate by being linked with an operation of the operation member (24) from the first operation position to the second operation position is urged by a second spring (28) to a non-rotation position side. Accordingly, it is possible to avoid an unnecessary emergency operation by generating an obvious difference in operation loads at a time of a normal operation and at a time of an emergency operation.