Fluid Headrest Adjustment With Impact Locking for Whiplash Protection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing headrest systems fail to conveniently and securely adjust in or against the direction of vehicle travel, particularly in accident situations, leading to potential whiplash risks due to abrupt movements.

Innovation Solution

A headrest with a fluid system that allows slow adjustment for comfort and safety, featuring a piston rod driven by a hydraulic or pneumatic system, and includes mechanisms to fix the head contact surface in place during accidents, such as a narrow gap between the piston and cylinder or a deformable disk, to minimize fluid exchange and prevent abrupt movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the fluid system allows free fluid exchange between reservoirs for comfort adjustment, then the headrest can be easily adjusted, but the system becomes too soft and cannot prevent whiplash in accidents

Engineering Contradiction:
Improveheadrest adjustabilityVSAvoidwhiplash protection
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The fluid system incorporates a flow restrictor that creates different flow characteristics in different directions. During normal adjustment, fluid flows freely in one direction for easy positioning. During impact, the flow restrictor limits fluid exchange to prevent abrupt movements. This directional differentiation of fluid flow properties resolves the contradiction between ease of adjustment and impact protection.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system transitions from a static fluid connection to a dynamic one with controlled resistance. The flow restrictor mechanism allows the fluid system to adapt its characteristics based on operating conditions - permitting free flow during normal use for comfort adjustment, but restricting flow during sudden impacts to provide whiplash protection, thus resolving the contradiction between operational ease and safety reliability.

Inventive Principle:
Principle #15Dynamics

2Reliability

If an additional fixation system is added to prevent whiplash, then safety is improved, but device complexity increases

Engineering Contradiction:
Improveaccident protectionVSAvoidsystem structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent integrates the fixation function directly into the existing fluid system by incorporating a flow restrictor mechanism within the fluid connection between reservoirs. This eliminates the need for separate fixation systems while maintaining whiplash protection, thus resolving the contradiction between safety improvement and device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The fluid system is designed to serve multiple functions: normal comfort adjustment through free fluid exchange, and accident protection through flow restriction. By making the fluid system multi-functional, the patent eliminates the need for additional dedicated fixation systems, resolving the contradiction between enhanced safety and reduced system complexity.

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

3Reliability

If the fluid system is made rigid for accident protection, then whiplash is prevented, but comfort adjustment becomes difficult

Engineering Contradiction:
Improveimpact resistanceVSAvoidadjustment ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The system uses a flow restrictor that dynamically adjusts fluid flow resistance based on operating conditions. During normal adjustment, the restrictor allows sufficient flow for easy positioning. During impact, it creates rigid behavior by limiting fluid exchange. This dynamic adaptation resolves the contradiction between comfort adjustment ease and impact resistance.

Inventive Principle:
Principle #15Dynamics

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 system ensures optimal comfort and safety adjustments while reducing the risk of whiplash by maintaining the headrest's position during impacts, eliminating the need for additional fixation systems and enhancing energy management.

Implementation Method 1

a gap (9) between the piston (6) and the cylinder wall (7) of the fluid system (4), through which the fluid (11) flows

Methodology Applied
Scientific EffectFluid flow through narrow gap: Viscous Damping

Implementation Method 2

this gap is designed so narrow that there is very little, if any, fluid exchange between the first and second reservoirs, so that the fluid system is very stiff overall

Methodology Applied
Scientific EffectViscous resistance in narrow gap: Viscous Damping

Data Source

PatentEP2477842B1Headrest and vehicle seat
Publication Date: 2013.09.04 JOHNSON CONTROLS GMBH
  • EP2477842B1 patent drawingFigure 1a~1b
  • EP2477842B1 patent drawingFigure 2~4b

AI summary

The invention relates to a head restraint equipped with a fluid system, and to a vehicle seat provided therewith.