Motor Vehicle Lock Primary Pawl Segmentation

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Solution Overview

Problem

Existing motor vehicle locks face challenges in ensuring jam-free operation with minimal design effort, particularly in transitioning from a pre-locked to a main locked state without primary pawl jamming, while maintaining low opening forces.

Innovation Solution

The motor vehicle lock design incorporates a primary pawl with two separate surfaces for supporting and blocking, allowing distinct engagement mechanisms for pre-locking and main locking states, and a blocking arrangement with pivotable blocking pawls that can be easily adapted to different positions, preventing jamming by adjusting the drop depth difference without modifying the latch bolt.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single support surface is used on the primary locking pawl, then the design complexity is reduced, but the lock cannot reliably distinguish between pre-locked and fully locked positions without risking jamming

Engineering Contradiction:
Improvejam-free operationVSAvoidlocking mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The primary locking pawl is segmented into two distinct support surfaces (first support surface and second support surface) that engage with different latch positions. This segmentation allows the mechanism to reliably distinguish between pre-locked and fully locked states without requiring additional complex components, as each surface is optimized for its specific engagement phase.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the primary locking pawl are given different functional qualities through the two support surfaces. The first support surface is positioned and oriented for pre-locking engagement, while the second support surface is configured for full locking engagement. This local differentiation enables reliable state distinction while maintaining overall design simplicity.

Inventive Principle:
Principle #3Local quality

2Reliability

If the latch is modified to accommodate different engagement depths, then the pre-locking and main locking states can be distinguished, but the latch bolt design complexity increases

Engineering Contradiction:
Improvestate differentiationVSAvoidlatch bolt complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of modifying the latch bolt to create state differentiation, the invention inverts the approach by modifying the primary locking pawl. The two support surfaces on the pawl are positioned to engage with the latch at different depths, allowing state differentiation to be achieved through the pawl design rather than the latch bolt design. This reduces complexity in the critical latch component.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The primary locking pawl acts as an intermediary element that translates the latch's position into distinct engagement states. By providing two support surfaces at different positions, the pawl mediates between the latch and the blocking mechanism, enabling reliable state differentiation without requiring modifications to the latch bolt itself.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Force

If the primary locking pawl is designed with two support surfaces, then opening forces are reduced through optimized gear ratio, but the manufacturing complexity increases

Engineering Contradiction:
Improveopening forceVSAvoidpawl manufacturing complexity
Core Design Contradiction:
ForceVSEase of manufacture

Solution Approach 1:

The primary locking pawl is segmented into two functional zones with distinct support surfaces positioned at different locations. This segmentation enables optimized engagement geometry for each locking phase, reducing the force required to transition between states. The segmented design achieves force optimization through geometric arrangement rather than material or structural complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The positions and orientations of the two support surfaces are carefully parameterized to optimize the gear ratio between the latch and primary locking pawl during engagement. By adjusting these geometric parameters, the mechanism achieves exceptionally low opening forces while maintaining manufacturability through standard machining operations.

Inventive Principle:
Principle #35Parameter changes

4Adaptability or versatility

If blocking pawls are made pivotable rather than fixed, then the blocking mechanism can adapt to different pawl positions, but the device complexity increases

Engineering Contradiction:
Improveblocking position adaptabilityVSAvoidblocking mechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The blocking pawls are designed to be pivotable rather than fixed, allowing them to dynamically adjust their position to match the engagement state of the primary locking pawl. This dynamic capability enables the blocking mechanism to adapt automatically to both pre-locked and fully locked positions without requiring complex control systems or multiple fixed components.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The pivotable blocking pawls serve multiple functions: they can block the primary locking pawl in the pre-locked position, allow transition to the fully locked position, and block the pawl in the fully locked position as well. This multi-functionality is achieved through a single simple pivotable structure rather than multiple fixed blocking elements, reducing overall complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3867473B1Motor vehicle lock
Publication Date: 2022.09.14 BROSE SCHLIESSSYSTEME GMBH & CO KG
  • EP3867473B1 patent drawingFigure 1
  • EP3867473B1 patent drawingFigure 2a~2b
  • EP3867473B1 patent drawingFigure 3

AI summary

The invention relates to a motor vehicle lock having a lock latch (5) which is pivotable in an opening direction (3) and in a closing direction (4) and which is pivotable into an open position, a pre-closing position and a main closing position, wherein the lock latch (5) is in holding engagement with a closing element (6), in particular with a closing bow, in the pre-closing position and in the main closing position, wherein the motor vehicle lock (1) has a primary pawl (9) which is pivotable in a latching direction and a lift-out direction and which supports the lock latch (5) against pivoting in the opening direction (3) in a pre-closing state in the pre-closing position and in a main closing state in the main closing position, wherein the lock latch (5) urges the primary pawl (9) in the pre-closing state and in the main closing state in the lift-out direction (8) of the primary pawl (9), wherein the motor vehicle lock (1) has a blocking arrangement (10) which blocks the primary pawl (9) in the pre-closing state and in the main closing state against pivoting in the lift-out direction of the primary pawl (9). It is proposed that the primary pawl (9) supports the lock latch (5) against pivoting in the opening direction (3) of the lock latch (5) in the pre-closing state via a first supporting surface (11) of the primary pawl (9) and in the main closing state via a separate, second supporting surface (12) of the primary pawl (9), and the blocking arrangement (10) blocks the primary pawl (9) against pivoting in the lift-out direction (8) of the primary pawl (9) in the pre-closing state via a first blocking surface (13) of the blocking arrangement (10) and in the main closing state via a separate, second blocking surface (14) of the blocking arrangement (10).