Motor Vehicle Door Lock Decoupling Mechanism

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Solution Overview

Problem

Motor vehicle door locks with closing/opening devices face significant comfort loss when the closing/opening device fails, requiring considerable forces to operate the locking mechanism and move the failed device, leading to mechanical inhibiting forces that hinder smooth operation.

Innovation Solution

The introduction of a third functional position for the closing/opening device in its idle state, where it is mechanically decoupled from the locking mechanism, allowing for unimpeded operation without additional forces, even if the closing/opening device fails, by incorporating a pawl that lifts off the locking mechanism using a link lever and spring tension.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the closing/opening device remains mechanically coupled to the locking mechanism in the idle state, then the basic functioning of the door lock is maintained, but considerable forces are required to operate the locking mechanism when the closing/opening device fails

Engineering Contradiction:
Improvebasic functioning of door lockVSAvoidoperational comfort when closing/opening device fails
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The closing/opening device is designed to dynamically change its coupling state with the locking mechanism. In the idle state (when not actuated), the device is mechanically decoupled from the locking mechanism, allowing easy operation. When actuated by a command from the control unit, the device couples to the locking mechanism to perform its closing function. This dynamic switching resolves the contradiction by providing both reliability during normal operation and ease of operation when the device fails.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system is segmented into two functional parts: the closing/opening device and the locking mechanism. The coupling between these parts is made controllable rather than permanent. A coupling lever with a coupling lug and coupling catch mechanism enables selective engagement and disengagement. This segmentation allows the closing/opening device to be separated from the locking mechanism when not in use, eliminating the operational resistance problem while maintaining functionality when needed.

Inventive Principle:
Principle #1Segmentation

2Extent of automation

If the closing/opening device is mechanically coupled to the locking mechanism during normal operation, then the locking mechanism can be actuated automatically, but significant operating forces are required to move the closing/opening device when it fails

Engineering Contradiction:
Improveautomatic closing functionVSAvoidoperating force required when device fails
Core Design Contradiction:
Extent of automationVSForce

Solution Approach 1:

The mechanical coupling between the closing/opening device and locking mechanism is made dynamic rather than static. The coupling lever with spring element automatically engages the coupling lug into the coupling catch during normal operation, enabling automatic actuation. When the device fails or is not actuated, the spring force maintains the coupled position, but the device can be easily disengaged by manual operation without excessive force, as the coupling mechanism is designed to release under controlled conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The coupling lever acts as an intermediary mechanism between the closing/opening device and the locking mechanism. It includes a coupling lug on the closing lever and a coupling catch on the locking mechanism. This intermediary element enables automatic force transmission during normal operation while providing a controlled interface that can be easily disengaged, reducing the force required to operate the system when the closing/opening device fails.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If the closing/opening device remains in contact with the locking mechanism in the rest position, then the system structure is simplified, but the locking mechanism cannot be opened without moving the closing/opening device which requires considerable forces

Engineering Contradiction:
Improvesystem structureVSAvoiddoor opening operation
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The coupling state is made dynamic based on the operational state of the closing/opening device. When the device is in its rest position and not actuated, the coupling lever automatically disengages the coupling lug from the coupling catch, creating a decoupled state. This allows the locking mechanism to be opened without the need to move the closing/opening device, significantly reducing the operational forces required while maintaining a relatively simple overall system structure.

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

Enables easy opening of the locking mechanism without moving the closing/opening device, reducing operational forces and ensuring comfortable use, especially in emergency situations where the closing/opening device is mechanically decoupled, allowing for effortless actuation of the locking mechanism.

Implementation Method 1

incorporating a pawl that lifts off the locking mechanism using a link lever and spring tension

Methodology Applied
Scientific EffectElastic force: Elasticity

Data Source

PatentEP2235304B1Motor vehicle door lock
Publication Date: 2012.08.08 KIEKERT AG
  • EP2235304B1 patent drawingFigure 1
  • EP2235304B1 patent drawingFigure 2
  • EP2235304B1 patent drawingFigure 3

AI summary

The invention relates to a motor vehicle door lock, equipped with a ratchet mechanism (1, 2) and a pulling/opening device (3 to 8). The pulling/opening device (3 to 8) adopts at least one first and second functional position during the actuation of the ratchet mechanism (1, 2). According to the invention, in the inactive state the pulling/opening device (3 to 8) passes into a third functional position (park position), in which it is mechanically decoupled from the ratchet mechanism (1, 2).