Closure Latch Double Pawl Mechanism Release Timing

Solution Overview

Problem

Existing closure latch assemblies for vehicle doors suffer from delayed and unpredictable release times due to clearance or 'play' between pawls and ratchets, leading to a 'popping noise' during abrupt releases. Additionally, they require complex packaging and lack optimized performance.

Innovation Solution

A closure latch assembly with a double pawl and double ratchet mechanism, featuring a primary ratchet, primary pawl, auxiliary ratchet, and auxiliary pawl, is designed to minimize play between components. This assembly includes a latch release mechanism with an auxiliary pawl release lever and an interface leg to ensure precise movement and predictable release.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If clearance or play is present between pawls and ratchets, then the latch mechanism can accommodate manufacturing tolerances and thermal expansion, but the release time is delayed and unpredictable

Engineering Contradiction:

Improverelease timing predictabilityVSAvoidrelease time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The auxiliary pawl is pre-positioned to engage with the primary pawl before the release lever is fully actuated. This preliminary engagement ensures that the primary pawl is ready to drop immediately when the release lever begins to move, eliminating delays caused by sequential engagement and improving release timing predictability.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The auxiliary pawl acts as an intermediary mechanism between the release lever and the primary pawl. It transfers and amplifies the release motion, ensuring that the primary pawl drops reliably and predictably when the release lever is actuated, thereby improving release timing without requiring direct engagement between the release lever and primary pawl.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If the secondary pawl is driven into engagement with the primary pawl to move the primary pawl to its open position, then the latch can be released, but a popping noise is generated from sudden abrupt release

Engineering Contradiction:

Improvelatch release functionVSAvoidpopping noise

Core Design Contradiction:

Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The auxiliary pawl is pre-positioned to engage with the primary pawl before the release lever is fully actuated. This preliminary engagement ensures that the primary pawl is ready to drop immediately when the release lever begins to move, eliminating delays caused by sequential engagement and improving release timing predictability.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The auxiliary pawl and auxiliary ratchet mechanism provides a cushioning effect by gradually transferring the release force. Instead of a sudden abrupt engagement, the auxiliary pawl progressively engages with the primary pawl, cushioning the impact and reducing or eliminating the popping noise while still achieving reliable latch release.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Ease of manufacture

If clearance is present between components, then assembly is easier and manufacturing is simpler, but lost motion is created and timing response is delayed

Engineering Contradiction:

Improveassembly simplicityVSAvoidrelease speed

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The auxiliary pawl is pre-positioned to engage with the primary pawl before the release lever is fully actuated. This preliminary engagement ensures that the primary pawl is ready to drop immediately when the release lever begins to move, eliminating delays caused by sequential engagement and improving release timing predictability.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The auxiliary pawl acts as an intermediary mechanism between the release lever and the primary pawl. It transfers and amplifies the release motion, ensuring that the primary pawl drops reliably and predictably when the release lever is actuated, thereby improving release timing without requiring direct engagement between the release lever and primary pawl.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS20250052096A1Closure latch assembly with double pawl mechanism

Publication Date: 2025.02.13 MAGNA CLOSURES INC

AI summary

A closure latch assembly for installation in a vehicle door and method of construction thereof is provided. The closure latch assembly has at least one ratchet, a primary pawl, and an auxiliary pawl. At least one ratchet is moveable between a striker capture position and a striker release position. The primary pawl is moveable between a closed position and an open position. The auxiliary pawl is moveable between a closed position and an open position. An auxiliary pawl release lever is moveable between a rest position, whereat the auxiliary pawl is located in its closed position and the primary pawl is located in its closed position, and an engaged position, whereat the auxiliary pawl is moved to its open position and the primary pawl is moved to its open position.