Aircraft Seat Pan Internal Spring Return Mechanism for Balanced Torque

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Solution Overview

Problem

Conventional aircraft seat pan return mechanisms using flat and coiled torsion springs are bulky and uneven, consuming valuable space and creating torque imbalances.

Innovation Solution

An internally housed return spring mechanism utilizing first and second spring mechanisms attached to stanchions, with the seat pan rotationally coupled to these stanchions, elongating to provide lift assistance and return the seat pan to a stowed position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If flat torsion springs are used in the return mechanism, then the seat pan can be returned to stowed position, but the closing torque is uneven between right and left sides

Engineering Contradiction:
Improveseat pan return functionVSAvoidtorque balance
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The return mechanism is divided into independent left and right spring assemblies, each housed in separate interior spaces of the stanchions. This segmentation allows each side to operate independently with its own extension spring, eliminating the torque imbalance issue that occurs with shared flat torsion springs while maintaining reliable return function.

Inventive Principle:
Principle #1Segmentation

2Reliability

If coiled torsion springs are used in the return mechanism, then the seat pan can be returned to stowed position, but valuable space within the seat pan is consumed

Engineering Contradiction:
Improveseat pan return functionVSAvoidspace utilization
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The extension springs are nested within the interior spaces of the stanchions, which are themselves integrated into the seat frame structure. This nesting approach allows the return mechanism to be housed within existing structural volumes rather than adding separate bulky spring components, thereby maintaining reliable return function while optimizing space utilization.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Volume of moving object

If extension springs are used in the return mechanism, then space is optimized and torque is balanced, but the springs must be housed within interior spaces of stanchions

Engineering Contradiction:
Improvespace utilizationVSAvoidstructural integration
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The stanchions serve multiple functions: they provide structural support for the seat pan, define interior spaces for housing spring mechanisms, and serve as mounting points for the extension springs. This multi-functionality reduces the need for additional dedicated components, thereby optimizing space utilization while managing structural integration complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 solution provides a compact and balanced seat pan closure mechanism that optimizes space utilization and ensures even torque distribution, enhancing ergonomic comfort and efficiency.

Implementation Method 1

rotation of the seat pan toward a deployed position of the seat pan elongates the first and second elongation springs thereby energizing the springs to provide lift assistance

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4353594B1Aircraft seat with internal seat pan return spring mechanism
Publication Date: 2025.11.26 AMI IND INC
  • EP4353594B1 patent drawingFigure 1A
  • EP4353594B1 patent drawingFigure 1B
  • EP4353594B1 patent drawingFigure 1C

AI summary

An aircraft seat assembly including first and second stanchions (202) forming interior spaces (204) open through forward slots (208). A seat pan (206) is pivotally attached to the stanchions (202) and includes rearward extensions (212) that extend through the forward slots (208) and are received in the interior spaces (204). First and second spring mechanisms (218) reside in the respective first and second interior spaces (204) and are attached at opposing ends to their respective stanchion (202) and to the seat pan (206). In use, rotating the seat pan (206) toward a deployed position elongates the first and second elongation springs (220) thereby energizing a return force of the spring mechanisms.