Aircraft Seat Leg Assembly with Split Rear Joint for Crash Energy Dissipation
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Solution Overview
Problem
Conventional seat leg assemblies in aircraft passenger seats face challenges in achieving optimal load distribution and energy absorption during crashes, as they either fail to dissipate enough energy due to stiffness or excessively deform and fail due to flexibility, posing risks to passenger safety.
Innovation Solution
A seat leg assembly design where the rear leg is split into upper and lower parts, with a brace integral to the lower part and connected to the floor, featuring a joint between the upper part and the brace that allows for built-in rotation resistance and load distribution, enabling efficient energy dissipation and improved structural integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the leg assembly is made stiff to prevent seat collapse during crash, then structural integrity is improved, but energy absorption capability deteriorates causing damage to internal organs and spinal column
Solution Approach 1:
The rear leg is divided into two separate parts: an upper rear leg and a lower rear leg. This segmentation allows each part to have different structural characteristics - the upper part can be designed for strength while the lower part provides flexibility and energy absorption through controlled deformation
Solution Approach 2:
The patent changes the structural parameters of the leg assembly by introducing a joint between the upper and lower rear legs with specific rotation resistance characteristics. This allows the system to transition from a purely stiff structure to one that can control deformation through adjusted rotational parameters at the joint
2Loss of energy
If the leg assembly is made flexible to improve energy absorption, then energy dissipation is improved, but structural integrity deteriorates causing excessive deformation and failure
Solution Approach 1:
By segmenting the rear leg into upper and lower parts connected by a joint, the patent creates a structure where flexibility can be localized at the joint while maintaining overall structural integrity. The joint allows controlled deformation for energy absorption without compromising the strength of the entire leg assembly
Solution Approach 2:
The joint between upper and lower rear legs introduces dynamic characteristics to the otherwise static leg assembly. The joint's rotation resistance allows the structure to adapt its stiffness during impact, providing controlled deformation that dissipates energy while maintaining structural integrity
3Ease of manufacture
If the seat leg assembly uses conventional integral design, then manufacturing simplicity is maintained, but load distribution capability is insufficient during crash
Solution Approach 1:
The patent segments the rear leg into separate upper and lower parts that can be manufactured independently using conventional processes, then assembled through a joint. This maintains manufacturing simplicity while enabling better load distribution through the multi-component structure
Solution Approach 2:
The patent adds a rotational dimension to the load path by introducing a joint that allows controlled rotation between upper and lower rear legs. This dimensional change enables the structure to distribute loads more effectively during impact by utilizing rotational degrees of freedom
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 enhances load distribution and energy absorption capabilities, improving passenger survivability by allowing for better energy dissipation and structural efficiency while maintaining the seat's integrity during impacts, reducing the risk of injury from excessive loads.
Implementation Method 1
a joint (112) formed between the upper part (104) and the brace (106)
Data Source
Figure 1a)~1b)
Figure 2
Figure 3~4
AI summary
A seat leg assembly for a passenger seat, a frame for a passenger seat, and a passenger seat. The seat leg assembly comprising a brace member configured to extend from a front end of a base frame of the passenger seat to a rear floor fitting; a front leg configured to extend from a front floor fitting to the brace member and connected to the brace member; a rear leg portion extending from a rear end of the base frame to the brace member; and a first joint structure connecting the rear leg portion to the brace member.