Aircraft Seat Backrest Locking Mechanism With Reduced Mass
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Solution Overview
Problem
Existing aircraft seat mechanisms require high-mass components to lock the backrest, which is disadvantageous for aircraft applications due to weight constraints.
Innovation Solution
A seat design featuring a pivot connection and a rack-type locking mechanism with a ring and indexer system, utilizing asymmetrical toothing profiles and elastic return means to reduce the mass of the blocking member, allowing for adjustable backrest inclination while minimizing weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional locking mechanism is used to lock the backrest, then the backrest can be securely locked at the desired inclination, but the mass of the locking member increases
Solution Approach 1:
The locking mechanism is divided into two independent functional components: a rack-type locking member that engages with the arm, and a separate indexer that locks the ring in rotation. This segmentation allows each component to be optimized for its specific function, reducing the overall mass while maintaining reliability.
Solution Approach 2:
The arm acts as an intermediary element between the backrest and the locking member. It transmits forces from the backrest to the locking member, reducing the forces to which the locking member is directly subjected. This force reduction allows for a lighter locking member design while maintaining adequate locking strength.
2Strength
If the locking member is designed to withstand high forces, then it can securely lock the backrest, but its mass increases
Solution Approach 1:
The arm serves as a force-distributing intermediary that reduces the peak forces transmitted to the locking member. By distributing forces more efficiently through the arm, the locking member can be designed with lower strength requirements, directly reducing its mass.
Solution Approach 2:
The locking mechanism utilizes rotational locking of the ring around the front transverse beam, adding a dimensional aspect to the force distribution. This rotational constraint distributes forces across different directions, reducing the burden on any single component and allowing for lighter design.
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 design reduces the mass of the blocking member by distributing forces more efficiently, enabling adjustable backrest inclination without increasing the overall seat mass, and allows for easy locking and unlocking of the backrest position.
Implementation Method 1
the teeth of the slider teeth and the teeth of the toothed sector have asymmetrical tooth profiles sized to ensure locking of the ring when the indexer is engaged and a thrust is exerted on the backrest to increase its inclination, and to cause disengagement of the indexer when sufficient thrust is exerted on the backrest to reduce its inclination
Implementation Method 2
comprising elastic return means returning the slide to its disengaged position
Implementation Method 3
a pivot connection carried by a rear transverse beam of the lower frame and by which the upper frame is connected to the lower frame
Implementation Method 4
a rack-type locking member carried at least in part by a front transverse beam of the lower frame, and capable of being in an engaged state to lock the front end in its current position
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The invention relates to a seat (1) intended to be fixed to the floor of a vehicle, comprising a seat (2) incorporating a lower frame (6), and a backrest (4) incorporating an upper frame (11) linked to the lower frame (6), the inclination of this backrest (4) being adjustable between a minimum inclination and a maximum inclination, this seat (1) comprising: - a pivot joint (P1) carried by a rear transverse beam (14) of the lower frame (6) and by which the upper frame (11) is linked to the lower frame (6); - an arm (23) rigidly attached to the upper frame (11) and comprising a front end (24); - a locking member (25) carried at least in part by a front transverse beam (13) of the lower frame (6), and being able to be in an engaged state to lock the front end (24) in its current position or in a disengaged state to release the front end (24).