Vehicle Seat Backrest Locking Device Ejection Lever Mechanism

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Solution Overview

Problem

Existing locking devices for vehicle seat backrests lack an efficient mechanism to transfer the backrest into an ejection position without requiring significant energy, and they often necessitate additional complex drive elements for folding and locking functions.

Innovation Solution

A locking device with an ejector lever that displaces the counter-element relative to the rotary latch lock when actuated by a control handle, allowing energy introduction via the handle, and incorporating a spring bias and lever mechanism to facilitate unlocking and prevent re-locking, enabling modular expansion of the rotary latch lock with an ejection function.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a locking device for vehicle seat backrests is designed without an ejection function, then the structure remains simple, but the backrest cannot be easily transferred into an ejection position without additional complex drive elements

Engineering Contradiction:
Improveease of backrest ejectionVSAvoidcomplexity of locking mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The operating handle is designed to perform multiple functions: it acts as both the unlocking mechanism and the ejection mechanism. When rotated, it first unlocks the rotary latch lock and simultaneously activates the ejection lever through the connecting element to displace the counter-element, enabling the backrest to be transferred into the ejection position without requiring separate drive elements

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

Solution Approach 2:

The unlocking function and ejection function are merged into a single operational sequence. The operating handle connects to both the rotary latch lock and the ejection lever via the connecting element, so that one rotational motion accomplishes both unlocking and ejecting the counter-element, eliminating the need for additional complex drive mechanisms

Inventive Principle:
Principle #5Merging (Combining)

2Force

If a powerful energy store is used to eject the counter-element, then the ejection function is strong, but the locking device requires more energy and complex energy storage components

Engineering Contradiction:
Improveejection forceVSAvoidenergy consumption
Core Design Contradiction:
ForceVSUse of energy by moving object

Solution Approach 1:

The user's manual operation of the operating handle provides the energy needed for ejection. The connecting element translates the rotational motion of the handle into linear displacement of the ejection lever, which moves the counter-element. This self-service mechanism eliminates the need for powerful energy stores, springs, or motors, as the user's input force directly performs the ejection function

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces complex mechanical energy storage systems (such as powerful springs or motors) with a direct mechanical transmission system. The connecting element acts as a simple mechanical linkage that converts the operating handle's rotation into ejection lever displacement, achieving the ejection function through straightforward mechanical advantage rather than stored energy

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Ease of operation

If the pawl can be easily rotated into unlocked position, then unlocking is simple, but the locking device may accidentally re-lock

Engineering Contradiction:
Improveease of unlockingVSAvoidprevention of accidental re-locking
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The ejection lever is activated in advance during the unlocking process. When the operating handle is rotated to unlock the rotary latch lock, the connecting element simultaneously displaces the ejection lever to move the counter-element out of the pawl's receptacle. This preliminary ejection action ensures that the counter-element cannot re-engage with the pawl, preventing accidental re-locking while maintaining simple unlocking operation

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The ejection function performs a preliminary anti-action by displacing the counter-element away from the pawl's locking position before the unlocking is complete. This prevents the counter-element from accidentally re-engaging with the receptacle after unlocking, as the ejection lever maintains the counter-element in a displaced position, thereby preventing harmful accidental re-locking

Inventive Principle:
Principle #9Preliminary anti-action

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 allows for comfortable unlocking and folding of the backrest without additional complex drive elements, preventing re-locking after the handle is actuated, thus enhancing user convenience and simplifying the locking mechanism.

Implementation Method 1

The latch is biased in an opening direction by a biased spring arrangement. The spring arrangement supports a rotary movement of the pawl as soon as the at least one securing means releases the rotary movement.

Methodology Applied
Scientific EffectSpring: Spring

Data Source

PatentEP3221182B1Locking device, especially for locking a backrest of a vehicle seat to a vehicle structure
Publication Date: 2019.01.02 ADIENT LUXEMBOURG HLDG SARL
  • EP3221182B1 patent drawingFigure 1~2
  • EP3221182B1 patent drawingFigure 3~4
  • EP3221182B1 patent drawingFigure 5~6

AI summary

The invention relates to a locking device (100), especially for locking a backrest (4) of a vehicle seat (1) to a vehicle structure (6), comprising a rotary latch-type lock (20) for locking a mating element (8), the locking device (100) further comprising an ejection lever (133) which, in an unlocked state of the rotary latch-type lock (20), moves the mating element (8) relative to the rotary latch-type lock (20) by actuating an operating handle (121).