Helmet Subliner with Segmented Viscoelastic Foam for Angular Acceleration
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Solution Overview
Problem
Current helmets do not adequately reduce head angular acceleration during impacts, which contributes to the risk of concussions and long-term injuries like chronic traumatic encephalopathy (CTE) due to repetitive head impacts.
Innovation Solution
A helmet design featuring a subliner system with radially partitioned energy-absorbing viscoelastic foam elements, including first, second, and third types of subliner elements, nested with double-sided nano tape for enhanced energy absorption and distribution, to mitigate head angular acceleration during impacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If traditional subliner materials are used, then comfort and fit are achieved, but head angular acceleration during impact is not adequately reduced
Solution Approach 1:
The subliner is divided into multiple independent foam elements arranged in an array, where each element can independently deform during impact. This segmentation allows for better distribution of impact forces and more effective reduction of head angular acceleration compared to traditional unified subliner designs.
Solution Approach 2:
The patent uses viscoelastic foam material that combines viscous and elastic properties to optimize energy absorption during impact while maintaining comfort during normal wear. This composite material behavior enables the subliner to provide both comfort and enhanced protection against head angular acceleration.
2Loss of energy
If energy absorbing foam material is used in the subliner, then impact force absorption is improved, but the complexity of the subliner system increases
Solution Approach 1:
The subliner is divided into multiple independent foam elements arranged in an array, where each element can independently deform during impact. This segmentation allows for better distribution of impact forces and more effective reduction of head angular acceleration compared to traditional unified subliner designs.
Solution Approach 2:
The patent specifies foam elements with particular density ranges (0.02 to 0.08 g/cc) and thickness variations (0.25 to 1.5 inches) to optimize energy absorption characteristics. By carefully controlling these parameters, the system achieves effective impact force absorption while managing the complexity through standardized specifications.
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 subliner system effectively reduces head angular acceleration, enhancing head protection by distributing and absorbing impact forces, thereby minimizing the risk of concussions and long-term injuries such as CTE.
Implementation Method 1
The at least one subliner element is constructed of an energy absorbing viscoelastic foam material
Implementation Method 2
The at least one subliner element is constructed of an energy absorbing viscoelastic foam material
Implementation Method 3
double-sided nano tape positioned therebetween such that the nested segments have side surfaces in direct contacting engagement with the nano tape
Data Source
AI summary
A helmet to be worn on a head of a wearer includes a shell comprised of a hard impact resistant material. The shell has inner and outer surfaces and is adapted to surround at least a portion of the cranial part of wearer's head with the inner surface of the shell being spaced from the wearer's head at an initial pre-impact relative position when the helmet is worn. A subliner, at least a part of which is adapted to be in contact with the wearer's head when the helmet is worn prior to an impact and during an impact, includes at least one subliner element extending from the inner surface of the shell. The at least one subliner element is constructed of an energy absorbing viscoelastic foam material. The at least one subliner element is radially partitioned into individual and independent segments. The independent segments are nested with respect to each other with double-sided nano tape positioned therebetween such that the nested segments have side surfaces in direct contacting engagement with the nano tape.