Motor Vehicle Lock Blocking Pawl Prevents Accidental Opening

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Solution Overview

Problem

Electrical latches in motor vehicles can unintentionally open due to defects, posing a safety risk to occupants.

Innovation Solution

A latch with a blocking pawl that prevents unscheduled opening, requiring manual movement from a blocking position to a non-blocking position to initiate electrical opening, using an electromotor with a worm gear and a microswitch for controlled operation, and a stop to protect mechanical components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If an electrical drive is used to move the pawl out of its ratchet position, then the force required to open the latch is minimized, but the latch may open in an unscheduled manner due to electrical defects

Engineering Contradiction:

Improveforce required to open latchVSAvoidunscheduled opening due to electrical defects

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

A blocking pawl is introduced as an intermediary mechanical component between the electrical drive and the pawl mechanism. This blocking pawl physically prevents the pawl from being moved out of its ratchet position unless the blocking pawl is first manually repositioned. The blocking pawl acts as a mechanical mediator that overrides electrical signals, ensuring that even if the electrical drive activates due to a defect, the latch cannot open without the intermediate step of manually moving the blocking pawl.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The blocking pawl is positioned in advance to block the movement path of the pawl before any electrical activation can occur. By establishing this preliminary mechanical block, the system prevents the harmful effect of unscheduled opening before it can happen, regardless of electrical drive activation. The blocking pawl creates a preliminary obstacle that must be overcome manually before the electrical drive can have any effect.

Inventive Principle:

Principle #9Preliminary anti-action

2Reliability

If a blocking pawl is added to prevent unscheduled opening, then safety is improved, but the device complexity increases

Engineering Contradiction:

Improveprevention of unscheduled openingVSAvoidnumber of components in locking mechanism

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The blocking pawl serves multiple functions within the latch mechanism: it blocks unscheduled opening, it can be manually moved to enable scheduled opening, and it works in conjunction with the existing electrical drive and pawl components. By making the blocking pawl a multi-functional element that integrates with the existing mechanism rather than a completely separate safety system, the increase in complexity is minimized while achieving the safety goal.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If the blocking pawl is designed to require manual movement, then unscheduled opening is prevented, but the ease of operation for scheduled opening is reduced

Engineering Contradiction:

Improveprevention of unscheduled openingVSAvoidmanual force required to move blocking pawl

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The blocking pawl is designed with different functional zones: one end that engages with the pawl to block movement (requiring only light force to disengage) and another end that can be manually actuated (requiring controlled manual movement). The local quality of the blocking surface is optimized to require minimal force to move, while the actuation point is designed to be easily accessible and operable. This localized differentiation allows the blocking function to be strong where needed while remaining easy to operate where accessed.

Inventive Principle:

Principle #3Local quality

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

Ensures the latch can only be opened in a scheduled manner, even with electrical defects, reducing the force required for manual operation and preventing accidental openings while protecting mechanical components.

Implementation Method 1

an electromotor (1) with a worm gear (5) attached to the motor shaft (4)

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS11274474B2Motor vehicle lock

Publication Date: 2022.03.15 KIEKERT AG

AI summary

The aim of the invention is to provide a lock for a motor vehicle, whereby the accidental opening of said lock is prevented. To achieve this aim, a lock comprises a locking mechanism with a rotary latch and a locking pawl for arresting the rotary latch in a latch position. In order to open the lock with minimum effort, an electric drive (1) is provided by means of which drive the locking pawl can be moved directly or indirectly out of its locking position. The lock is further provided with a movable blocking pawl (2), which can impede the electric drive (1) from opening the lock. For the locking mechanism to be electrically opened, the blocking pawl (2) needs to be moved out of its blocking position and the electric drive (1) needs be to actuated.