Motorized Headrest Guide Structure for Tilt-Free Adjustment

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Solution Overview

Problem

Existing height-adjustable headrests lack a compact and easy-to-adjust design, compromising comfort and safety for vehicle occupants, with manual adjustments being cumbersome and prone to tilting.

Innovation Solution

A height-adjustable headrest featuring a base support element with multiple openings and a support element with corresponding guide parts, enabled by an electric motor-driven rack and gear system for self-locking longitudinal adjustment, combined with a second motor for vertical adjustment and a locking mechanism for secure positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual longitudinal adjustment is used, then device complexity is reduced, but ease of operation deteriorates due to cumbersome adjustment and tilting issues

Engineering Contradiction:
Improveease of longitudinal adjustmentVSAvoidcomplexity of adjustment mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent replaces the manual mechanical adjustment system with an electric motor-driven rack and pinion system. The motor automatically positions the support element longitudinally, eliminating the need for manual operation while preventing tilting through precise controlled movement. This substitution directly improves ease of operation by providing automatic, tilt-free adjustment.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The rack and pinion mechanism provides self-locking functionality, where the engaged teeth naturally maintain the positioned state without additional locking mechanisms or continuous power application. The system serves itself by maintaining position through the mechanical engagement of the rack teeth with pinion teeth, reducing the need for complex active locking systems.

Inventive Principle:
Principle #25Self-service

2Ease of operation

If multiple guide parts and openings are used, then ease of operation improves for longitudinal adjustment, but device complexity increases

Engineering Contradiction:
Improveease of longitudinal displacementVSAvoidcomplexity of guide structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The guide structure is segmented into multiple discrete openings in the base support element and corresponding guide parts in the support element. This segmentation allows the motor-driven pinion to engage with specific rack teeth at different longitudinal positions, enabling precise stepwise adjustment. The segmented design improves operability by providing discrete, easily achievable position stops.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The multiple openings and guide parts serve multiple functions: they guide longitudinal displacement, provide engagement points for the pinion-rack mechanism, and act as position stops. This multi-functionality reduces the need for separate components for each function, thereby managing complexity while improving adjustment ease.

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

3Ease of operation

If electric motor-driven rack and gear system is used, then ease of operation improves for longitudinal adjustment, but device complexity increases

Engineering Contradiction:
Improveease of electromechanical adjustmentVSAvoidcomplexity of drive mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The manual mechanical adjustment system is replaced with an electric motor-driven rack and pinion system. The motor provides automated, controlled movement along the longitudinal axis, eliminating manual effort and preventing tilting through precise positioning. This substitution significantly improves ease of operation despite adding electrical components.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The rack and pinion mechanism provides self-locking functionality through the engagement of gear teeth. Once the motor positions the support element, the interlocked teeth maintain the position without requiring continuous power or additional locking mechanisms. This self-service characteristic reduces the need for complex active positioning systems.

Inventive Principle:
Principle #25Self-service

4Volume of moving object

If compact design is achieved, then volume is reduced, but ease of operation may deteriorate

Engineering Contradiction:
Improvevolume of headrest assemblyVSAvoidease of adjustment
Core Design Contradiction:
Volume of moving objectVSEase of operation

Solution Approach 1:

The support element is nested within the base support element, with the guide parts fitting into the openings. The rack mechanism is integrated into the guide structure, and the pinion is mounted on the motor shaft. This nesting arrangement achieves a compact overall volume while maintaining full functionality of the adjustment mechanism.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

Multiple functions are merged into integrated components: the guide parts serve both as structural guides and as racks for the pinion engagement. The motor serves both to drive the pinion for longitudinal adjustment and to provide the driving force for the height adjustment mechanism. This merging reduces the number of separate components, achieving compactness without sacrificing ease of operation.

Inventive Principle:
Principle #5Merging (Combining)

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 headrest provides easy, convenient, and secure height and longitudinal adjustments, enhancing comfort and safety by allowing precise positioning and reducing unwanted tilting, while maintaining a compact design.

Implementation Method 1

a first rack element is arranged on a guide part, which is operatively related to a gear, wherein the gear is arranged on a first shaft which can be driven by means of the first motor

Methodology Applied
Scientific EffectRack and pinion mechanism: Rack and Pinion

Implementation Method 2

a first rack element is arranged on a guide part, which is operatively related to a gear, wherein the gear is arranged on a first shaft which can be driven by means of the first motor

Methodology Applied
Scientific EffectFriction and gear engagement: Friction

Data Source

PatentEP3802208B1Hight adjustable and longitudinally adjustable headrest
Publication Date: 2023.11.22 ADIENT US LLC
  • EP3802208B1 patent drawingFigure 1
  • EP3802208B1 patent drawingFigure 2
  • EP3802208B1 patent drawingFigure 3

AI summary

According to the invention, a height-adjustable headrest has a base support element (2) and a support element (3), which is arranged in the base support element and can be guided for longitudinal sliding in an X direction. In order to form a guide, the base support element (2) comprises a number of openings (2.1) and the support element (3) comprises a number of guide parts (3.1). The shape of the number of openings (2.1) corresponds with the shape of the number of guide parts (3.1).