Vehicle Seat Backrest Detent and Blocking Lever Mechanism

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Solution Overview

Problem

Existing vehicle seat easy-entry systems fail to effectively separate functions for moving the seat into an easy-entry position and a flat floor position, with the backrest often not fully folding forward due to counteraction from Bowden cables, limiting the seat's adjustability and loading capacity.

Innovation Solution

A vehicle seat design featuring a pivoting backrest with a detent mechanism secured by a blocking lever, allowing the seat to be moved into an easy-entry position and a flat floor position, using a control ring and Bowden cables to maintain the backrest's angular position and lock the rail pair, enabling separate function control through resilient elements and actuation handles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single actuation lever is used to control both easy-entry position and flat floor position, then the device complexity is reduced, but the adaptability is worsened because the backrest cannot be fully folded forward for flat floor configuration

Engineering Contradiction:
Improveactuation mechanismVSAvoidbackrest position control
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent segments the actuation control into two independent parts: an unlocking lever for easy-entry position control and a separate actuation mechanism for flat floor position control. This segmentation allows each mechanism to be optimized for its specific function, enabling the backrest to achieve full forward folding for flat floor configuration without being constrained by the easy-entry mechanism's Bowden cable counteraction.

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If the vehicle seat is displaced into the easy-entry position, then the accessibility to rear seat row is improved, but the backrest cannot be fully folded forward due to Bowden cable counteraction

Engineering Contradiction:
ImproveaccessibilityVSAvoidbackrest folding range
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent extracts the flat floor actuation control from the easy-entry unlocking lever system. By providing a separate actuation mechanism specifically for flat floor position control, the system eliminates the Bowden cable counteraction limitation that prevents full backrest folding when the seat is in the easy-entry position. This allows the backrest to achieve complete forward folding regardless of the seat's longitudinal position.

Inventive Principle:
Principle #2Taking out (Extraction)

3Stability of the object's composition

If the detent mechanism is used to secure the backrest in pivoted-forward position, then the stability is improved, but the ease of operation is worsened because additional blocking mechanism is needed

Engineering Contradiction:
Improvebackrest position stabilityVSAvoidbackrest release operation
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The patent merges the detent mechanism with the blocking lever into a single integrated assembly. The blocking lever is positioned to directly interact with the detent, allowing the blocking lever to prevent detent release when the seat is in the easy-entry position. This merged design provides stable backrest positioning while maintaining ease of operation through a single blocking lever component that controls both the detent engagement and the blocking function.

Inventive Principle:
Principle #5Merging (Combining)

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

Enables precise control over the backrest's movement, preventing backward pivoting until the seat is out of the easy-entry position and allowing full folding for a flat floor configuration, enhancing accessibility and loading capacity.

Implementation Method 1

a blocking lever (12) which can be pivoted into a blocking position in which the detent (10) is blocked by means of a resilient element (14)

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The blocking lever (12) is operationally connected by means of a Bowden cable (28) to an activation element (30) which can be actuated by means of a control ring (16)

Methodology Applied
Scientific EffectMechanical Force Transmission: Mechanical Force

Implementation Method 3

at least one lockable fitting (6) for pivotably connecting the backrest (4) to the seat member (2)... the backrest (4) is secured by means of a detent (10) in the pivoted-forward position

Methodology Applied
Scientific EffectMechanical Fastening: Mechanical Fastener

Data Source

PatentEP3243695B1Vehicle seat
Publication Date: 2019.03.13 ADIENT LUXEMBOURG HLDG SARL
  • EP3243695B1 patent drawingFigure 1
  • EP3243695B1 patent drawingFigure 2a~2b
  • EP3243695B1 patent drawingFigure 3a~3b

AI summary

The invention relates to a vehicle seat (1), in particular a motor vehicle seat, having a seat member (2) and a backrest (4) which can be pivoted about a pivot axis (S), at least one lockable fitting (6) for pivotably connecting the backrest (4) to the seat member (2), at least one rail pair (8) for longitudinally adjusting the vehicle seat (1) and a rail lock (8a) for locking the at least one rail pair (8). The vehicle seat (1) can be moved into an easy-entry position which can be assumed for easier accessibility to a rear seat row and in which the vehicle seat (1) with respect to at least one position for use which is suitable for transporting persons is displaced into a front longitudinal position by means of the at least one rail pair (8), the backrest (4) is pivoted forwards about the pivot axis (S) and the backrest (4) is secured in the pivoted-forward position by means of a detent (10). Furthermore, the detent (10) can be blocked by means of a blocking lever (12) in order to prevent release of the backrest (4) as long as the vehicle seat (1) is displaced into a longitudinal position which corresponds to the easy-entry position.