Deployable Armrest With Pawl And Ratchet Height Adjustment
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Solution Overview
Problem
Conventional armrests in aircraft pilot seats are difficult to access and deploy due to their stowed location, especially in crowded flight decks, and require a tilt adjustment mechanism, which disrupts seat styling and increases complexity.
Innovation Solution
A deployable and height-adjustable armrest assembly featuring a pawl and ratchet mechanism with a rack and lever system that allows single-handed operation, eliminating the need for a tilt adjustment mechanism and enabling easy stowing and deployment without disrupting seat styling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the armrest is configured to stow in a recess formed in the seat back, then the armrest maintains a compact stowed location, but access to the armrest and deployment become difficult considering the stowed location and close proximity of an adjacent console
Solution Approach 1:
The armrest transitions from a horizontal stow position in the seat back recess to a vertical deployed position extending downward. This dimensional change allows the armrest to be compact when not in use while providing easy access when needed, as the pilot can reach forward rather than having to reach behind the seat. The vertical orientation also positions the armrest away from the console area, improving accessibility in crowded flight decks.
2Strength
If the armrest is coupled to the seat back, then the armrest is supported by the seat structure, but the armrest requires a tilt adjustment mechanism to compensate for seat back recline motion
Solution Approach 1:
The armrest is extracted from the seat back coupling and repositioned to be supported by a dedicated support bracket attached to the seat frame. This separation allows the armrest to have its own independent support mechanism that does not require tilt adjustment, eliminating the complex linkage needed to compensate for seat back recline motion while maintaining structural support.
3Device complexity
If the armrest is located alongside the seat back in a conventional configuration, then the armrest structure is simple, but the armrest disrupts the styling cues of the seat and makes access difficult in crowded flight decks
Solution Approach 1:
The armrest is designed as a dynamic component that can transition between a compact vertical stowed position and a horizontal deployed position. This dynamic capability allows the armrest to maintain a clean, styling-friendly appearance when not in use while providing full functionality when needed. The vertical stowed position eliminates disruption to seat styling cues and improves accessibility in crowded flight decks.
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
Facilitates easy and intuitive deployment and adjustment of the armrest, improving accessibility and maintaining the aesthetic integrity of the seat design, while allowing multiple adjustable positions for enhanced comfort.
Implementation Method 1
A biasing member is coupled between the lever and the rack receiver to bias the pawl toward an engaged position
Implementation Method 2
a pawl carried by the lever is configured to engage in the plurality of detents, one at a time, to lock the armrest in a selected armrest deployment position
Implementation Method 3
a rack slidable relative to the rack receiver, the rack including an elongate slot formed along a longitudinal length of the rack
Data Source
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AI summary
The present disclosure provides a deployable and height adjustable armrest assembly for use with, for example, an aircraft pilot seat. The assembly includes an armrest (136) positioned atop a rack (118) comprising a plurality of detents (154) each corresponding to a deployed armrest position. A lever (122) carries a pawl (140) that travels along one edge of the rack which locates in a selected one of the plurality of detents to lock the armrest in one of its deployed positions. The armrest is configured to be raised manually to deploy and adjust the armrest upward. The lever is configured to be actuated manually to disengage the pawl from its engagement in one of the detents to lower or return the armrest to its stowed positions. The armrest is particularly advantageous in close quarters such as a flight deck, or where a stowed armrest can be used to expand the width of the seat bottom.