Deformable Actuator for Crash-Activated Head Restraint

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Solution Overview

Problem

Existing crash-activated head restraints in vehicles often have complex and uncomfortable actuator designs that are slow to respond in rear crashes, failing to effectively reduce the gap between the head and head restraint to prevent injuries.

Innovation Solution

A vehicle seat with a crash-activated head restraint and an actuator featuring a deformable body that reversibly deforms under crash forces, connected by a force transmitter, such as a Bowden cable, to move the head restraint closer to the occupant, with springs to return to the initial position post-crash, enhancing comfort and response.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional actuators are used to activate the head restraint, then the head restraint can move towards the occupant in a rear crash, but the actuator design becomes complicated and reduces comfort

Engineering Contradiction:

Improvecrash activation reliabilityVSAvoidactuator design complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the complex actuator mechanism from the head restraint system and replaces it with a simple deformable body that passively responds to crash forces. The deformable body is integrated directly into the head restraint structure, eliminating the need for separate actuators, sensors, and control systems while maintaining crash activation reliability.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The deformable body automatically deforms under crash forces without requiring external control systems. The head restraint system serves itself by using the crash force directly to deform the body and move the head restraint, eliminating the need for complex actuation mechanisms, sensors, and power sources.

Inventive Principle:

Principle #25Self-service

2Reliability

If traditional actuators are used to activate the head restraint, then the head restraint can move towards the occupant, but the actuation speed becomes too slow

Engineering Contradiction:

Improvecrash activation reliabilityVSAvoidactuation speed

Core Design Contradiction:

ReliabilityVSSpeed

Solution Approach 1:

The patent replaces the mechanical actuator system with a direct mechanical deformation mechanism. The deformable body converts crash forces directly into motion of the head restraint through elastic deformation, eliminating the delays associated with sensor detection, signal processing, and actuator activation in traditional systems.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The deformable body is pre-configured in a state ready to deform immediately upon crash impact. The elastic elements are positioned and tensioned beforehand so that when crash forces occur, the deformation and head restraint movement begin instantly without any activation delay.

Inventive Principle:

Principle #10Preliminary action

3Object-affected harmful factors

If the head restraint moves closer to the occupant during crash, then injury prevention is improved, but the gap reduction mechanism becomes more complex

Engineering Contradiction:

Improvehead injury riskVSAvoidgap reduction mechanism complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent changes the physical state and geometry of the deformable body during crash deformation. The body transitions from its initial configuration to a deformed state, changing parameters such as length, curvature, and volume to directly drive the head restraint movement, providing a simple yet effective gap reduction mechanism.

Inventive Principle:

Principle #35Parameter changes

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 solution effectively reduces the gap between the head and head restraint during a rear crash, minimizing head, neck, and back injuries while maintaining comfort and quick actuation, with the head restraint returning to its original position after crash forces dissipate.

Implementation Method 1

a deformable body (2), which deforms reversible under the force resulting from the rearward movement of body of the seat occupant during and/or after the rear crash

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Implementation Method 2

The head restraint and the actuator are connected by a force transmitter, which transmits a force, resulting from the deformation of the deformable body from the actuator to the head restraint

Methodology Applied

Scientific EffectMechanical force transmission: Mechanical Force

Data Source

PatentUS8727437B2Actuator for crash activated head restraint

Publication Date: 2014.05.20 ADIENT US LLC

AI summary

Vehicle-seat comprising a seat base, a seatback and a head restraint reduces the gap between the head of a seat occupant and the front side of the head restraint in case of a crash, the vehicle seat further comprising an actuator, which is located in the seat back, which comprises a deformable body, which deforms reversible under the force resulting from the rearward movement of body of the seat occupant during and/or after the rear crash, and which comprises a first and a second end, whereas at least one end, preferably both ends, is/are slideably supported in a basis, whereas the head restraint and the actuator are connected by a force transmitter, which transmits a force, resulting from the deformation of the deformable body from the actuator to the head restraint.