Helmet Segmented Inner Shell for Oblique Impact Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing helmets do not provide adequate protection against oblique impacts, which can cause rotational injuries such as concussion, subdural hematomas, and diffuse axonal injuries due to angular acceleration of the brain, as they fail to effectively dissipate rotational energy.
Innovation Solution
A helmet design featuring an inner shell composed of multiple segments that can slide independently relative to an outer shell, facilitated by a low friction sliding interface and connectors, allowing each segment to move relative to the outer shell and distribute rotational energy across the entire head surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the outer shell is split into segments to allow sliding, then protection against oblique impacts is improved, but the shell becomes more prone to snagging on external objects
Solution Approach 1:
The inner shell is divided into multiple segments that can slide independently relative to each other and the outer shell. This segmentation allows the inner shell to deform and absorb rotational energy from oblique impacts while the outer shell remains intact and resistant to snagging.
Solution Approach 2:
The helmet incorporates a dynamic system where the inner shell segments can move relative to the outer shell through low-friction interfaces. This dynamic capability enables the helmet to adapt to impact forces by allowing controlled sliding motion, dissipating rotational energy while maintaining structural integrity.
2Ease of manufacture
If the inner shell is made as a single continuous piece, then manufacturing is simpler, but it cannot effectively dissipate rotational energy from oblique impacts
Solution Approach 1:
The inner shell is segmented into multiple independent sections that can move relative to each other. This segmentation transforms the single continuous structure into a multi-component system capable of dissipating rotational energy through relative motion between segments, while still being manufacturable through modular construction.
Solution Approach 2:
The inner shell transitions from a static continuous structure to a dynamic segmented system. The segments are connected through low-friction interfaces that allow controlled sliding motion during impact, enabling energy dissipation while maintaining ease of manufacture through standardized modular components.
3Strength
If the inner shell segments are connected rigidly, then structural integrity is improved, but sliding capability and energy dissipation are reduced
Solution Approach 1:
The connection between inner shell segments transitions from rigid to semi-rigid, allowing controlled relative motion. The connectors provide sufficient structural integrity to maintain shell shape while permitting sliding capability through low-friction interfaces, enabling both strength and energy dissipation.
Solution Approach 2:
The mechanical properties of the connectors between inner shell segments are optimized to provide a balance between rigidity and flexibility. The connectors have controlled friction characteristics that allow sliding under impact loads while maintaining structural integrity during normal use, changing the effective stiffness parameter based on applied force.
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 design significantly reduces rotational acceleration, minimizing the risk of rotational injuries by distributing and dissipating rotational energy, thereby enhancing protection against oblique impacts.
Implementation Method 1
a low friction sliding interface between the inner shell and the outer shell configured to facilitate sliding of the inner shell relative to the outer shell
Implementation Method 2
an inner shell lining an inner surface of the outer shell and formed from an energy absorbing material configured to protect against a radial component of an impact
Data Source
Figure 1~3C
Figure 4~5
Figure 6~7
AI summary
A helmet comprises: an outer shell; an inner shell lining an inner surface of the outer shell and formed from an energy absorbing material configured to protect against a radial component of an impact to the wearer's head; and a low friction sliding interface between the inner shell and the outer shell configured to facilitate sliding of the inner shell+ relative to the outer shell in response to an impact to the wearer's head to protect against a tangential component of the impact; wherein the inner shell comprises a plurality of shell segments each shell segment being configured to slide relative to the outer shell at the sliding interface and each shell segment being configured to move relative to each other shell segment.