Infinitely Adjustable Armrest Mechanism to Eliminate Locking Noise
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Solution Overview
Problem
Existing retractable armrests in vehicle seats, particularly in aircraft, suffer from noise issues during adjustment, lack of adjustability beyond fully up and fully down positions, and require a gap in upholstery or premature wear of materials, while also needing to meet crashworthiness and fuel efficiency standards.
Innovation Solution
A mechanism using gears and bearings allows for infinite vertical adjustability of the armrest, eliminating locking noise and requiring no gap in upholstery, with a butterfly control mechanism that converts horizontal force into vertical movement, ensuring silent operation and compliance with safety standards.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an M-lock style touch latch device is used for locking the armrest, then the armrest can be locked in fully up or fully down position, but the armrest produces noise during locking and has no adjustability beyond two positions
Solution Approach 1:
The patent replaces the traditional M-lock style touch latch mechanical system with a cable-actuated locking mechanism. The cable runs through a series of pulleys and connects to a control element on the armrest, allowing the armrest to be locked at any vertical position along the rack without the noise and limitation of traditional mechanical latches. This substitution eliminates the harmful noise while maintaining reliable locking capability.
2Reliability
If an M-lock style touch latch device is used, then the armrest can be locked in position, but the armrest requires a gap in upholstery or soft foam which leads to premature wear
Solution Approach 1:
The cable-actuated mechanism eliminates the need for the armrest to move upward to disengage a mechanical latch. Instead, the cable can be actuated at any position, allowing the armrest to be locked without requiring upward movement that would create gaps or compress foam. This substitution preserves upholstery integrity and prevents premature wear while maintaining reliable locking.
3Adaptability or versatility
If a four bar linkage mechanism is used for vertical adjustment, then the armrest can be adjusted vertically, but the mechanism produces noise and has limited adjustability
Solution Approach 1:
The patent replaces the four bar linkage mechanism with a cable-pulley system that allows smooth, quiet vertical adjustment of the armrest along the rack. The cable runs through multiple pulleys to provide mechanical advantage and control, eliminating the noise and limited adjustability of the four bar linkage while maintaining full vertical adaptability.
4Strength
If high-strength materials are used to meet crashworthiness standards, then the armrest can support user weight and meet safety regulations, but the armrest becomes heavier and bulkier
Solution Approach 1:
The patent changes the structural parameters of the armrest by using a sleek, streamlined design with optimized cross-sectional dimensions. The armrest maintains sufficient strength to support user weight and meet crashworthiness standards through efficient structural geometry rather than simply increasing material quantity. This parameter optimization reduces weight and bulk while preserving safety performance.
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 quiet, infinitely adjustable armrest that meets crashworthiness and fuel efficiency requirements without visible controls or upholstery gaps, enhancing user comfort and compliance with safety regulations.
Implementation Method 1
a one-way bearing having a first rotational state allowing the rack downward movement when the lock is in the disengaged position
Implementation Method 2
a lock engageable with the one-way bearing between the rack and the seat bottom frame
Implementation Method 3
A pivoting displacement of the first arm can pivot the paddle and displace the second arm, and the sliding member can be displaced in a vertical direction by the second arm
Data Source
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AI summary
A vehicle seat having a bottom frame, a seat back connected to the frame, and an armrest capable of upward and downward movement. The armrest includes a seat bracket connecting the armrest to the frame and a vertically variable adjustment mechanism. The mechanism has a control disposed in the armrest, a lock actuated to an engaged or disengaged position by the control, a rack disposed in a generally vertical direction, and a one-way bearing acting as pinion and having two rotational states. The first rotational state is a locked state where the lock is engaged and prevents the one-way bearing from rotating, preventing the rack and armrest from a downward movement. The second rotational state is a free state where the lock is in the engaged position and a force is applied in the upward direction, the one-way bearing can rotate, allowing the rack and armrest an upward movement.