Progressive Spring Aircraft Seat Backrest Reset Mechanism
Solution Overview
Problem
Aircraft seating devices lack enhanced comfort features, particularly in providing a comfortable reclining mechanism that resets the backrest without exerting force on passengers, while maintaining a strong and space-efficient design.
Innovation Solution
The aircraft seating device incorporates a spring device with a progressive spring characteristic and a combination of spring units, including a gas pressure spring, which provides an increasing spring force with travel, allowing for a significant recline angle and effortless reset, ensuring comfort and stability without manual adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional spring device with constant force is used, then the backrest can be easily reclined, but the return force is insufficient to reset the backrest without manual assistance
Solution Approach 1:
The spring device transitions from a static constant-force spring to a dynamic progressive spring that adapts its force output based on deflection distance. The spring force increases progressively as the backrest reclines, providing gentle initial resistance that eases operation, then building sufficient force at maximum deflection to reliably reset the backrest automatically without manual assistance.
Solution Approach 2:
The spring characteristic changes from constant force to progressive force by modifying the spring parameters (coil spacing, wire diameter gradient, or spring rate variation along the length). This parameter change enables the spring to deliver different force levels at different stages of backrest deflection, optimizing both ease of reclining and automatic return capability.
2Reliability
If a strong spring force is applied throughout the recline range, then the backrest returns reliably, but excessive force is required to initiate reclining
Solution Approach 1:
The progressive spring provides dynamic force modulation where the spring constant effectively increases during the recline process. Initially, when deflection is small, the spring remains relatively soft requiring minimal force. As deflection increases, the progressive characteristic engages, increasing the force output to ensure reliable return, thus adapting to operational needs at different stages.
Solution Approach 2:
The spring force application occurs in distinct phases: a low-force initial phase for easy reclining initiation, followed by a progressive force-building phase, and finally a high-force phase at maximum deflection for reliable return. This periodic variation in force application optimizes both ease of operation and return reliability.
3Ease of operation
If a progressive spring characteristic is implemented, then comfort is improved with less force required, but the device complexity increases
Solution Approach 1:
The progressive spring can be implemented by segmenting the spring structure into zones with different coil densities or wire diameters. Each segment contributes to the progressive characteristic, allowing the complex force profile to be achieved through modular structural divisions rather than a monolithic complex design.
Solution Approach 2:
The progressive spring acts as an intermediary mechanical element that translates simple backrest movement into variable force output. Rather than requiring complex control systems or multiple actuators, the progressive spring characteristic itself mediates the force delivery, providing comfort-oriented progressive resistance through its inherent mechanical property.
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 achieves a high level of passenger comfort by allowing a substantial recline angle while ensuring the backrest resets without additional force, maintaining structural integrity and space efficiency, with a maximum recline of over 15 cm and a spring force greater than 20 N, enhancing the overall seating experience.
Implementation Method 1
a spring device (16) which is designed to provide a force curve (26) that has an increasing gradient with increasing spring travel
Implementation Method 2
the spring device comprises a spring unit with a first spring element and at least one second spring element connected in series with the first
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
The invention relates to an aircraft seating device, in particular an aircraft seat, comprising a mounting unit (10), a backrest (12) pivotable relative to the mounting unit (10), and an adjustment mechanism (14) including a spring device (16) designed to provide a restoring force for the backrest (12). It is proposed that the spring device (16) provide a force curve (26) with an increasing slope as the spring travel increases.