Dual-Stage Cinch Latch Assembly for Decklid

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Solution Overview

Problem

Current power-operated closure latch assemblies for motor vehicle decklids lack a safe and efficient power cinch function, particularly due to the risk of finger pinching when closing the decklid.

Innovation Solution

A power-operated closure latch assembly that integrates a dual-stage cinch mechanism, where the first stage is non-driven, allowing the decklid to close under its own weight, and the second stage is driven, using a power actuator to ensure safe and complete closure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a power-operated closure latch assembly is used to automate decklid closure, then user convenience is improved, but the risk of finger pinching increases

Engineering Contradiction:

Improveuser convenienceVSAvoidfinger pinching risk

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The closure process is divided into two distinct stages: a first non-driven stage where the decklid closes under its own weight, and a second driven stage where the power actuator engages to complete the closure. This segmentation allows the dangerous powered motion to be separated from the initial closing phase, eliminating finger pinching risk during the most vulnerable period while maintaining automation benefits.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The decklid is allowed to perform the initial closing action on its own weight before the power actuator engages. This preliminary non-driven action positions the decklid in a safe state where the gap is sufficient to prevent finger pinching, and the ratchet is in a position where the powered cinch can safely engage without risking injury.

Inventive Principle:

Principle #10Preliminary action

2Device complexity

If a single-stage powered closure system is used, then device complexity is reduced, but closure reliability and safety are compromised

Engineering Contradiction:

Improvesystem simplicityVSAvoidclosure safety

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The system dynamically transitions between two operational modes: a passive non-driven mode for the initial closure phase, and an active driven mode for the final cinch phase. The ratchet mechanism automatically engages and disengages the power actuator based on the decklid position, creating a dynamic system that adapts its complexity to the operational requirements at each stage.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The closure operation occurs in periodic phases: first the non-driven closing phase, then the powered cinch phase. This periodic alternation between passive and active phases ensures that the powerful actuator only operates when safe and necessary, maintaining reliability without requiring continuous complex control.

Inventive Principle:

Principle #19Periodic action

3Speed

If the power actuator engages early during closure, then closure speed is improved, but the risk of injury increases

Engineering Contradiction:

Improveclosure speedVSAvoidinjury risk

Core Design Contradiction:

SpeedVSObject-affected harmful factors

Solution Approach 1:

The system applies preliminary anti-action by allowing the decklid to close naturally under gravity first, creating a safety buffer zone. Only after this preliminary phase establishes a safe gap does the power actuator engage, preventing the harmful effect of high-speed powered closure when fingers could be pinched.

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The non-driven first stage acts as a cushioning phase that absorbs the initial closing motion at low speed, ensuring that when the high-speed powered actuator engages later, the decklid and striker are already in safe positions that prevent injury while allowing rapid completion of closure.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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 dual-stage cinch mechanism provides a safe and efficient power cinch function, preventing finger pinching and ensuring reliable closure of the decklid, while also enhancing user convenience and safety.

Implementation Method 1

a power actuator operable to rotate a drive member in an actuation direction

Methodology Applied

Scientific EffectElectric motor actuation:

Implementation Method 2

the drive cam includes a first trigger cam feature operable to move the pawl from its ratchet holding position to its ratchet releasing position

Methodology Applied

Scientific EffectCam mechanism: Cam

Implementation Method 3

a spring-loaded lift mechanism operable to move the closure panel, herein described as decklid, from its fully-closed position to its partially-open position

Methodology Applied

Scientific EffectSpring mechanism: Spring

Data Source

PatentUS12291899B2Latch assembly with power release and dual stage cinch function

Publication Date: 2025.05.06 MAGNA CLOSURES INC

AI summary

A closure latch assembly for a decklid configured to provide a power release operation and a power cinch operation. The closure latch assembly includes a latch mechanism, a latch cinch mechanism, a drive mechanism, and a power actuator. The power actuator interacts with the drive mechanism to provide a power release of the latch mechanism and a power cinch of the latch cinch mechanism.