Eccentric Latch Mechanism for Aircraft Tray Table Stowage
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Solution Overview
Problem
Aircraft tray tables pose a risk of head and neck injuries during crashes due to protrusions that can catch the crash test dummy's chin, leading to failed safety tests, and existing solutions either deploy inadvertently or add unnecessary weight and complexity.
Innovation Solution
A latch mechanism using an eccentric member with a rotatable axis and working surfaces that, when actuated, displaces a passenger article relative to its support assembly, allowing it to be securely stowed within a seatback shroud pocket, preventing protrusions into the passenger's head path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a locking unit with a lifting unit and rotary knob is used to secure the storage surface, then the storage surface can be securely locked, but the mechanism adds complexity and weight
Solution Approach 1:
The patent extracts the essential locking function from the complex lifting unit and rotary knob mechanism, using only the eccentric member and cam surface arrangement. This removes unnecessary components while retaining the core security function, simplifying the overall mechanism.
Solution Approach 2:
Instead of using a complex lifting mechanism to secure the table, the patent inverts the approach by using a simple eccentric cam mechanism that locks the table in place through geometric constraint rather than active lifting force, reducing complexity.
2Ease of operation
If tray tables are positioned to provide adequate support, then passenger comfort is improved, but the tables create a lip under the video shroud that can catch the crash test dummy's chin during HIC testing
Solution Approach 1:
The latch mechanism ensures the tray table is securely held in its support position before HIC testing occurs. The eccentric member and cam surface arrangement maintains the table's position during testing, preventing it from moving into the head trajectory while still providing the necessary support lip for passenger comfort.
Solution Approach 2:
The patent converts the potentially harmful support lip that could catch the dummy's chin into a beneficial feature by ensuring it remains in a fixed, controlled position through the latch mechanism. The same lip that provides passenger comfort is prevented from becoming a hazard by the secure locking arrangement.
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 mechanism effectively secures passenger articles like tray tables, preventing them from contributing to head and neck injuries during crashes while maintaining minimal weight and intuitive operation, ensuring compliance with safety standards by keeping the head trajectory clear.
Implementation Method 1
an eccentric member having an axis and a periphery that is rotatably connected with the latch mechanism. The periphery has a major working surface and a minor working surface, the major working surface being farther from the axis than the minor working surface. When the eccentric member is rotated, the eccentric member can engage with the support assembly such that the eccentric member causes the passenger article to displace relative to the support assembly
Implementation Method 2
the eccentric member causes the passenger article to displace relative to the support assembly
Data Source
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AI summary
Described are latching mechanisms having an eccentric member configured to interact with a support assembly, such that the eccentric member can cause a passenger article to displace relative to the support assembly. Also described are seat assemblies employing latching mechanisms for causing a passenger article to displace into a stowed configuration in the seat assemblies, and methods of stowing a passenger article.