Rear Seat Handle Interlock Using Seat Back Rotation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing interlock mechanisms for vehicle rear seats are complex, expensive, and require synchronized timing and close tolerances, failing to effectively prevent erroneous operation into a misuse position when the seat back is rotated forward onto the seat cushion.

Innovation Solution

A handle interlock assembly that selectively decouples the release handle from the seat cushion latch release, using a handle pivot link, latch pivot link, and interlock bracket to prevent rotation of the latch pivot link when the seat back is folded towards the seat cushion, thereby preventing the vehicle rear seat from being repositioned into an easy-entry position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing interlock mechanisms are used to prevent erroneous operation, then seat position control is achieved, but device complexity increases and manufacturing cost increases

Engineering Contradiction:
Improveprevention of erroneous operationVSAvoidinterlock mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the interlock function from a separate complex mechanism and integrates it directly into the existing handle assembly. The interlock arm is coupled to the handle pivot link, allowing the handle structure itself to control latch release based on seat back position, thereby preventing erroneous operation without adding a separate complex interlock system

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the interlock function with the handle assembly by coupling the interlock arm to the handle pivot link. This integration combines multiple functions (handle operation, latch release control, and position-based interlocking) into a single unified mechanism, reducing overall device complexity while maintaining reliability

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If existing interlock mechanisms are used to prevent misuse position, then safety is improved, but manufacturing cost increases

Engineering Contradiction:
Improveprevention of misuse positionVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent employs simple, inexpensive components such as the interlock arm, pivot links, and cable connections that can be manufactured at low cost. These basic mechanical elements provide the necessary interlock function without requiring expensive materials or complex manufacturing processes

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The interlock mechanism is designed to be self-regulating through the mechanical coupling of the interlock arm to the handle pivot link. The system automatically prevents latch release when the seat back is in the folded position without requiring external control systems, sensors, or complex actuation mechanisms, thereby reducing manufacturing cost

Inventive Principle:
Principle #25Self-service

3Reliability

If existing interlock mechanisms are used, then erroneous operation is prevented, but synchronized timing and close tolerances are required

Engineering Contradiction:
Improveprevention of erroneous operationVSAvoidsynchronized timing and tolerances
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent creates a mechanically coupled system where the interlock arm and handle pivot link move together as a unified assembly. This coupling ensures that the interlock function is always in sync with handle operation without requiring precise timing coordination or complex control systems

Inventive Principle:
Principle #12Equipotentiality

Solution Approach 2:

The patent divides the interlock function into discrete mechanical segments (interlock arm, handle pivot link, cable connections) that are easily manufactured and assembled with standard tolerances. Each component is simple in design, allowing for straightforward manufacturing without requiring close tolerances or complex synchronization

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3840984B1Handle interlock utilizing seat back rotation
Publication Date: 2023.09.13 MAGNA SEATING INC
  • EP3840984B1 patent drawingFigure 1
  • EP3840984B1 patent drawingFigure 2~3
  • EP3840984B1 patent drawingFigure 4~5

AI summary

An interlock mechanism prevents erroneous operation of a vehicle rear seat. The vehicle seat has a seat back rotatably coupled to a seat cushion. The interlock mechanism includes a handle pivot link, a latch pivot link, and an interlock bracket rotatably coupled to a pivot pin. When the seat back is in an upright position, the interlock bracket releasably couples the handle pivot link to the latch pivot link such that rotation of the handle pivot link rotates the latch pivot link causing the cushion latches to be released. When the seat back is folded towards the seat cushion, the interlock bracket is moved to an interlock position decoupling the handle pivot link and the latch pivot link such that rotating the handle pivot link does not rotate the latch pivot link and does not release the cushion latches.