Passenger seat frame
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional seat leg assemblies in aircraft passenger seats face challenges in balancing stiffness for crashworthiness with the need to absorb energy without causing injury to passengers, as they either fail to deform sufficiently during crashes or are too stiff, leading to potential organ damage.
Innovation Solution
A seat leg assembly design featuring a split rear leg with a brace member and joint structure that allows for improved load distribution and energy absorption, incorporating a diagonal brace and a pivot joint with segmented flat surfaces to manage loads and facilitate energy dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the leg assembly is made too stiff to prevent seat collapse during crash, then structural integrity is improved, but energy absorption capability deteriorates causing potential organ damage to passengers
Solution Approach 1:
The rear leg is divided into two separate portions (first rear leg portion and second rear leg portion) that can deform independently. This segmentation allows the structure to absorb energy through controlled deformation of individual segments while maintaining overall structural integrity, resolving the contradiction between stiffness and energy absorption.
Solution Approach 2:
The leg assembly is designed with dynamic characteristics that allow it to transition from a stiff structural support during normal operation to a energy-absorbing deformable structure during crash. The separate rear leg portions are designed to deform in a controlled manner during impact, enabling the structure to adapt its stiffness characteristics based on loading conditions.
2Loss of energy
If the leg assembly is made too flexible to absorb energy during crash, then energy absorption capability is improved, but structural integrity deteriorates causing seat collapse
Solution Approach 1:
By segmenting the rear leg into two portions connected by a joint, the design allows controlled deformation at the joint while maintaining structural integrity through the connecting mechanism. The joint structure enables energy absorption through rotational movement and controlled deformation, preventing complete structural failure.
Solution Approach 2:
The joint structure acts as an intermediary element between the two rear leg portions, facilitating controlled deformation and energy absorption while maintaining structural connectivity. This intermediary joint allows the structure to deform in a controlled manner rather than failing catastrophically.
3Ease of manufacture
If the leg assembly uses conventional integral design, then manufacturing simplicity is improved, but load distribution capability deteriorates
Solution Approach 1:
The rear leg is segmented into two separate portions that can be manufactured independently and then assembled through a joint structure. This segmentation allows for optimized load distribution paths while maintaining manufacturing feasibility through separate component production and assembly.
Solution Approach 2:
The joint structure introduces a rotational degree of freedom between the two rear leg portions, adding a dimensional aspect to load distribution. This allows the structure to distribute loads not only through the traditional vertical path but also through rotational movement and lateral force components.
Data Source
AI summary
A seat leg assembly for a passenger seat includes a brace member to extend from a front end of a base frame of the passenger seat to a rear floor fitting; a front leg 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.