Safety Belt Anchor Plate With Programmed Deformation Under Impact

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing seat belt anchoring systems in vehicles face challenges in limiting the force exerted on passengers during a front impact, particularly in vehicles with limited space or weak body structures, where the tearable sheet metal may not suffice to prevent tearing or breakage.

Innovation Solution

A seat belt anchor plate with a deformable section that includes fold lines in sheet metal, allowing relative rotation and energy absorption, thereby reducing the tension on the seat belt and preventing tearing or breakage, is designed to manage the forces exerted during a front impact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If tearable sheet metal is used to limit seat belt force, then the force on passenger is reduced, but the vehicle bodywork may tear instead when body strength is insufficient

Engineering Contradiction:
Improveseat belt force on passengerVSAvoidvehicle bodywork integrity
Core Design Contradiction:
ForceVSReliability

Solution Approach 1:

The anchoring plate is divided into a rigid part and a deformable part, with the deformable part further segmented into multiple zones (first deformable zone with fold lines, second deformable zone with progressive deformation features). This segmentation allows controlled deformation in specific areas while maintaining overall structural integrity, preventing uncontrolled tearing of the vehicle bodywork.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The deformable part acts as an intermediary element between the rigid anchoring plate and the vehicle bodywork. It absorbs and redistributes the impact forces through controlled deformation, preventing the transmission of excessive forces that would cause bodywork tearing while still limiting the seat belt force on the passenger.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Strength

If rigid anchoring elements are used to withstand 15,000 N pull, then the seat belt strength is ensured, but the force on passenger during impact cannot be limited

Engineering Contradiction:
Improveseat belt anchoring strengthVSAvoidseat belt force on passenger during impact
Core Design Contradiction:
StrengthVSForce

Solution Approach 1:

The anchoring plate transitions from a purely rigid structure to a dynamic structure with controlled deformability. The deformable part is designed to remain rigid under normal conditions (withstand 15,000 N pull) but undergo controlled deformation when impact forces exceed the threshold, automatically adjusting the force transmission characteristics based on the loading condition.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The mechanical properties of the anchoring plate are changed by introducing a deformable part with different material properties or structural characteristics compared to the rigid part. This allows the system to maintain high strength under normal conditions while enabling force limitation through controlled parameter changes (deformation) under impact conditions.

Inventive Principle:
Principle #35Parameter changes

3Volume of moving object

If space is limited in the vehicle, then the anchoring device size must be reduced, but the tearable sheet metal solution becomes unsuitable

Engineering Contradiction:
Improveanchoring device sizeVSAvoidforce absorption capability
Core Design Contradiction:
Volume of moving objectVSForce

Solution Approach 1:

The deformable part is integrated within the confines of the rigid anchoring plate structure, with deformation features (fold lines, progressive deformation zones) nested within the available space. This allows the force absorption mechanism to be contained within a compact volume, making the solution suitable for vehicles with limited space while maintaining adequate energy absorption capability.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 deformable section effectively absorbs impact energy, reducing the force exerted on passengers and preventing damage to the anchor plate or vehicle bodywork, ensuring safer restraint without tearing or breakage.

Implementation Method 1

designed to deform, under the effect of a tensile force applied to the locking means and the intensity of which is greater than a predetermined threshold value, so that the deformation causes a relative rotation of the first and second parts to absorb part of the energy of an impact

Methodology Applied
Scientific EffectEnergy absorption through deformation: Deformation

Implementation Method 2

The deformable section comprises a first fold line formed in a sheet metal connecting the first and second parts, the first fold line constituting an axis around which the relative rotation takes place during the deformation of the deformable section

Methodology Applied
Scientific EffectRotation around fold line axis: Hinge

Data Source

PatentEP4313695B1Safety belt anchoring and guide plate with programmed deformation
Publication Date: 2024.12.04 STELLANTIS AUTO SAS
  • EP4313695B1 patent drawingFigure 1~2

AI summary

The invention relates to a safety belt anchoring plate (1) for a motor vehicle (2), comprising a first part (5) having guide means (6) for guiding the sliding movement of a safety belt, the plate (1) having a second part (14) having locking means (16) for locking a seat back on the plate (1), the plate (1) further having a deformable section (22) connecting the first (5) and second (14) parts, which is designed to deform under the effect of a pulling force applied to the locking means (16) and the intensity of which is greater than a predetermined threshold value, with the result that the deformation causes a relative rotation of the first (5) and second (14) parts.