Side Airbag Cushion Tether Layout for Stable Occupant Restraint

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing vehicular airbag devices face challenges in improving occupant restraint performance without increasing complexity or cost, as methods like enlarging the airbag cushion or raising pressure are limited by installation constraints.

Innovation Solution

A vehicular side airbag device with a simple configuration, featuring an airbag cushion attached to a side frame, an inflator, and an external tether that pulls the rear end of the cushion toward the frame, aligning it with the frame to suppress oscillation and enhance restraint performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the airbag cushion dimensions are increased or pressure is raised to improve restraint performance, then occupant restraint performance is improved, but the device complexity and installation constraints are worsened

Engineering Contradiction:
Improveoccupant restraint performanceVSAvoiddevice configuration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the spatial orientation and positioning parameters of the airbag cushion by introducing the external tether system. Instead of increasing cushion dimensions or pressure, the tether modifies the positional parameters of the airbag relative to the side frame, achieving improved restraint performance through geometric reconfiguration rather than scaling up existing components.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The external tether acts as an intermediary element between the airbag cushion and the side frame. This mediator component enables precise positioning and oscillation suppression without requiring direct structural integration or complex mounting mechanisms, thereby maintaining device simplicity while achieving the desired restraint performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If upper panel and retractor are added to pull airbag to seatback side, then occupant restraint performance is improved, but device complexity and installation cost are worsened

Engineering Contradiction:
Improveoccupant restraint performanceVSAvoidnumber of elements
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the positioning and restraint functions into a single external tether system that integrates with the existing side frame structure. Rather than adding separate upper panel and retractor components, the tether combines multiple functions (positioning, alignment, oscillation suppression) into one element, reducing the total number of components while achieving equivalent or superior restraint performance.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The external tether serves multiple functions simultaneously: it positions the airbag cushion relative to the side frame, maintains alignment during deployment, and suppresses oscillation. This multi-functional design eliminates the need for separate dedicated components for each function, thereby reducing device complexity and installation requirements.

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

3Reliability

If external tether is added to pull rear end of airbag cushion toward side frame, then airbag alignment and restraint performance are improved, but device complexity is worsened

Engineering Contradiction:
Improveairbag alignment and restraint performanceVSAvoiddevice configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The external tether is implemented as a flexible strap or film-like component that connects the airbag cushion to the side frame. This flexible implementation allows the tether to accommodate the dynamic movement and expansion of the airbag while maintaining the desired positioning, avoiding the need for rigid mechanical linkages or complex articulation mechanisms.

Inventive Principle:
Principle #30Flexible shells and thin films

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 device effectively reduces occupant movement and rotational behavior with a simple design, improving restraint performance by maintaining the airbag cushion in alignment with the side frame, thereby minimizing injury risk.

Implementation Method 1

the external tether is in a taut state between the airbag cushion, and the side frame when the airbag cushion is expanded and deployed

Methodology Applied
Scientific EffectTension: Tension

Implementation Method 2

the external tether pulls the rear end portion of the airbag cushion toward the side frame

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP4596332A1Vehicular side airbag device
Publication Date: 2025.08.06 AUTOLIV DEV AB
  • EP4596332A1 patent drawingFigure 1A~1B
  • EP4596332A1 patent drawingFigure 2A~2B
  • EP4596332A1 patent drawingFigure 3~4

AI summary

PROBLEM To provide a vehicular side airbag device enabling improving occupant restraint performance of the airbag cushion with a simple configuration. SOLUTION The airbag module 110 of the side airbag device 100 includes an airbag cushion 112 that is in a prescribed stowed form and is attached to the outside of a side frame 108 in the width direction of a seat back 104, an inflator 114 that is attached to the outside of the side frame 108 together with the airbag cushion 112, and an external tether 138 that extends from a connection portion 142 that connects to a rear end portion 140 of the airbag cushion 112, passes over a front edge 148 of the side frame 108, and is connected to the inside of the side frame 108 in the width direction below the rear end portion 140. The external tether 138 is placed in a taut state between the airbag cushion 112 and the side frame 108 when the airbag cushion 112 is expanded and deployed.