Exterior Helmet Width Adjustment via Flexible Coupling

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Solution Overview

Problem

Existing protective helmets with exterior-adjustable head-width devices often compromise wearer comfort due to stiffening of the rear head support ring, either through housing enclosures or telescopic rods, which affect usability and fit.

Innovation Solution

A head-width adjusting device is integrated directly into the helmet shell, utilizing a flexible element connecting the adjusting wheel to the head support ring, allowing for axial flexibility and radial movement without mechanical stiffening, enabling comfortable and secure fit adjustments without a housing on the head support ring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the adjusting device is fitted inside a housing on the head support ring, then the mechanism is encapsulated and compact, but the head support ring is stiffened in the rear region which is uncomfortable for the wearer

Engineering Contradiction:
Improveencapsulation of adjusting mechanismVSAvoidwearer comfort
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The adjusting mechanism (adjusting wheel, catch mechanism, uncoupling mechanism) is extracted from the head support ring area and relocated to the helmet shell. Only a minimal guide seat remains on the head support ring, eliminating the housing that caused stiffening while maintaining the adjustment function through the flexible element connection.

Inventive Principle:
Principle #2Taking out (Extraction)

2Ease of operation

If the head-width adjusting device is fitted directly on the helmet shell, then wearer comfort is improved without stiffening the head support ring, but the mechanism becomes more complex with flexible elements

Engineering Contradiction:
Improvewearer comfortVSAvoidadjusting mechanism structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

A flexible element (spring or bellows) is used to connect the adjusting wheel on the helmet shell to the guide seat on the head support ring. This flexible element transmits the adjustment force while accommodating the relative movement between the shell and head support ring, providing a simpler solution than rigid telescopic rods.

Inventive Principle:
Principle #30Flexible shells and thin films

3Device complexity

If telescopic rods are used to connect the adjusting wheel to the head support ring, then the mechanism is simplified, but the head support ring is stiffened which reduces wearer comfort

Engineering Contradiction:
Improveadjusting mechanism structureVSAvoidwearer comfort
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The patent replaces rigid telescopic rods with a flexible element (spring or bellows) that connects the adjusting wheel to the guide seat. This flexible element maintains the simplified mechanism structure while avoiding the stiffening effect on the head support ring, thereby improving wearer comfort.

Inventive Principle:
Principle #30Flexible shells and thin films

4Reliability

If the adjusting mechanism is located inside the helmet, then it is protected from damage, but it becomes difficult to access for operation

Engineering Contradiction:
Improveprotection of adjusting mechanismVSAvoidaccessibility of adjusting wheel
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The adjusting wheel and associated mechanisms are extracted from the interior of the helmet and mounted on the exterior helmet shell. This makes the adjusting wheel easily accessible to the wearer's fingers for operation, while the critical components remain protected within the helmet structure.

Inventive Principle:
Principle #2Taking out (Extraction)

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

This design ensures a firm and comfortable fit for various head sizes with easy external adjustability, preventing pressure points and maintaining optimal wearer comfort by decoupling the adjusting mechanism from the head support ring's stiffness.

Implementation Method 1

a flexible element which is flexible in the axial direction, i.e. between the helmet shell and the head support ring, and is rigid in the radial direction

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2457459B1A protective helmet with a head-width adjusting device adjustable from the exterior
Publication Date: 2015.03.04 DRAGER SAFETY AG & CO KAAA
  • EP2457459B1 patent drawingFigure 1~2
  • EP2457459B1 patent drawingFigure 3
  • EP2457459B1 patent drawingFigure 4

AI summary

A protective helmet is provided with a head-width adjusting device adjustable from the exterior, wherein an adjusting wheel (5) disposed rotatably at the head side of the helmet shell (6) is connected to a toothed wheel (2) via a mechanically connected flexible element (4) for the transmission of the turning moment, wherein the toothed wheel (2) is disposed in a guide seat (1) in active connection with the head support ring (3), in such a way that the open ends of the head support ring (3) of the protective helmet, which are provided with complementary teeth, can be moved towards or away from one another for the head-width adjustment depending on the direction of rotation.