Helmet Outer Shell Rotation for Oblique Impact Protection
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Solution Overview
Problem
Conventional helmets do not provide adequate protection during oblique impacts, which can result in significant tangential forces leading to rotational acceleration of the brain and increased risk of injuries such as bridging vein rupture and diffuse axonal injuries.
Innovation Solution
A helmet design featuring an impact absorbing layer and a detachable outer shell connected by a connector that allows the outer shell to separate from the impact absorbing layer during an impact, reducing the transfer of tangential forces by enabling the outer shell to rotate and absorb normal forces, thereby minimizing rotational acceleration of the head.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the outer shell is rigidly connected to the impact absorbing layer, then the structural strength and stability are improved, but the protection against oblique impacts with tangential forces deteriorates
Solution Approach 1:
The helmet is divided into separate components: an outer shell and an impact absorbing layer, connected by detachable connectors. This segmentation allows the outer shell to rotate independently during oblique impacts, reducing the transfer of tangential forces to the head, while maintaining structural integrity during normal use.
Solution Approach 2:
The connector is designed to be dynamic rather than rigid, allowing it to detach or rotate under specific impact conditions. This enables the outer shell to move independently during oblique impacts, converting harmful rotational forces into beneficial relative motion between components, thereby protecting the head.
2Object-affected harmful factors
If the outer shell is detachable during impact, then the protection against tangential forces is improved, but the structural stability deteriorates
Solution Approach 1:
The connector's mechanical properties are designed to change under impact conditions. It maintains a stable connected state during normal use but transitions to a detached or rotated state when subjected to forces exceeding a predetermined threshold, thereby providing conditional stability that adapts to different loading scenarios.
Solution Approach 2:
The connector acts as an intermediary element between the outer shell and impact absorbing layer. It mediates the interaction between these components, providing a controlled connection that allows for selective detachment based on impact severity, thus balancing structural stability with impact protection.
3Object-affected harmful factors
If the connector allows outer shell separation during impact, then the reduction of rotational acceleration is improved, but the device complexity increases
Solution Approach 1:
The connector is designed to automatically detach or rotate in response to impact forces without requiring external control systems. The mechanism uses the impact energy itself to trigger the separation, eliminating the need for sensors, actuators, or complex control logic, thereby minimizing added complexity while achieving the desired protective function.
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 helmet design reduces the risk of injuries from oblique impacts by minimizing rotational acceleration and velocity of the head, offering improved protection compared to conventional foam helmets, with a 25% reduction in rotational acceleration and 45% reduction in rotational velocity.
Implementation Method 1
at least one impact absorbing layer which is designed to absorb a portion of the forces to which the helmet is subjected during an impact
Implementation Method 2
the outer shell is able to rotate about the impact absorbing layer when not connected to the impact absorbing layer by the connector
Data Source
AI summary
A helmet (100) including an impact absorbing layer (102), an outer shell (104) and a connector (106, 114). The outer shell is mounted on the outer surface of the impact absorbing layer. The connector connects the outer shell to the impact absorbing layer, to retain the outer shell on the impact absorbing layer. The connector is also arranged to allow the outer shell to separate from the impact absorbing layer when the helmet is subject to an impact.