Motor Vehicle Door Lock Rotary Latch Pawl Nesting

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Solution Overview

Problem

Existing locking devices for motor vehicle doors and hatches face challenges in compact design due to space limitations, especially in vehicles with electric opening functions, and lack efficient mechanisms to prevent unintentional opening.

Innovation Solution

A compact locking device featuring a ratchet and pawl mechanism with a spring-biased pawl that rotates with the rotary latch, utilizing a stop with multiple surfaces to securely hold the latch in the closed position and prevent unintended opening, allowing for both manual and electrical operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the locking device is designed to be compact to save installation space, then the installation space requirement is reduced, but the mechanism complexity increases due to the need for efficient space utilization

Engineering Contradiction:
Improveinstallation spaceVSAvoidmechanism complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The pawl is rotatably mounted on the rotary latch, nesting the pawl within the rotary latch structure. This eliminates the need for a separate housing for the pawl mechanism, significantly reducing the overall installation space while maintaining functional complexity through integrated design

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The stop is integrated into the lock case as a single piece, combining the stop function with the housing structure. This merging of components reduces the number of separate parts and simplifies the overall device architecture, addressing the complexity concern while achieving compactness

Inventive Principle:
Principle #5Merging (Combining)

2Area of stationary object

If the pawl is rotatably mounted on the rotary latch to save space, then the installation space is reduced, but the reliability may be affected due to the compact arrangement

Engineering Contradiction:
Improveinstallation spaceVSAvoidlocking reliability
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The stop features multiple surfaces (first stop surface and second stop surface) with different orientations, providing localized engagement points for the pawl. This ensures reliable locking through precise geometric relationships between the pawl and stop surfaces, maintaining high reliability despite the compact integrated arrangement

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The pawl spring continuously biases the pawl toward the locking position, ensuring the pawl is always prepared to engage with the stop surfaces. This preliminary positioning action guarantees reliable engagement and prevents unintended opening, maintaining high reliability in the compact design

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If the pawl spring biases the pawl in the direction of rotation to ensure compact design, then the device complexity is reduced, but the force required for operation may increase

Engineering Contradiction:
Improvedevice complexityVSAvoidoperating force
Core Design Contradiction:
Device complexityVSForce

Solution Approach 1:

The pawl is designed to rotate on its mounting axis on the rotary latch, allowing dynamic adjustment of the pawl's angular position. This rotational freedom enables the pawl to smoothly engage and disengage from the stop surfaces, reducing the force required for operation while maintaining the compact spring-biased design

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The locking mechanism operates through rotational movement of the pawl on its mounting axis, adding a rotational dimension to the linear spring bias. This dimensional change allows the compact spring mechanism to effectively control the pawl's engagement with the stop surfaces while minimizing the operating force through rotational leverage

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 provides a reliable, compact, and efficient locking mechanism that prevents unintentional opening while allowing for easy electrical or manual operation, saving space for additional components like electric opening devices.

Implementation Method 1

a pawl spring (12) for biasing the pawl (2) in a direction of rotation

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP3615752B1Motor vehicle door lock
Publication Date: 2021.04.28 KIEKERT AG
  • EP3615752B1 patent drawingFigure 1
  • EP3615752B1 patent drawingFigure 2

AI summary

The invention relates to a closing device for a door or hatch of a motor vehicle, comprising a locking mechanism with a rotary latch 1 and a pawl 2 for holding the rotary latch 1 in a closed position, wherein the pawl 2 is attached to the rotary latch 1 in a rotatable manner. A particularly compact design can thus be facilitated, in particular in a motor vehicle door lock.