Retractable Aircraft Cargo Hook With Torsion Spring Recessing
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Solution Overview
Problem
Existing cargo hooks for aircraft are intrusive and pose challenges in designing safety systems, requiring additional backup structures, risking damage to lanyards and increasing the risk of component damage during crashes.
Innovation Solution
A retractable cargo hook system utilizing a torsion spring to bias the hook towards a preferred orientation, allowing it to retract into a recessed portion of the fuselage and minimize damage during crashes, eliminating the need for bungee cables and reducing the hook's footprint.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional intrusive cargo hook is used, then the cargo hook can securely hold cargo, but it increases the risk of damage to aircraft components and lanyards during crashes
Solution Approach 1:
The cargo hook system transitions from a static fixed position to a dynamic retractable position. The hook can extend when needed for cargo attachment and retract into the fuselage during crash conditions, allowing the system to adapt its position based on operational requirements versus safety requirements.
Solution Approach 2:
The harmful intrusive element (the cargo hook) is extracted from its fixed position and removed from the critical crash path by retracting it into the fuselage. This separates the cargo holding function from the crash safety requirement.
2Object-affected harmful factors
If a retractable cargo hook system is implemented, then damage to aircraft components is minimized during crashes, but the device complexity increases
Solution Approach 1:
The torsion spring provides automatic self-service functionality by biasing the cargo hook toward a retracted position. The spring automatically returns the hook to its safe retracted position after deployment without requiring additional actuators or complex control systems.
Solution Approach 2:
The complex powered retraction system is replaced with a passive mechanical torsion spring mechanism. This substitution eliminates the need for motors, sensors, and control electronics while achieving the same safety function through simple mechanical biasing.
3Weight of moving object
If the cargo hook is made retractable, then the footprint and weight of the safety system are reduced, but the manufacturing complexity increases
Solution Approach 1:
The cargo hook assembly is merged with the fuselage structure, integrating the hook, torsion spring, and mounting mechanism into a single unified component set. This consolidation reduces the number of separate parts and simplifies manufacturing compared to assembling multiple discrete components.
4Ease of operation
If a torsion spring is used to bias the cargo hook, then the hook automatically returns to a preferred orientation, but the manufacturing precision requirements increase
Solution Approach 1:
The torsion spring's physical parameters (wire diameter, coil diameter, number of coils, material properties) are selected and configured to provide the desired biasing force and retraction characteristics. By carefully controlling these parameters during manufacturing, the system achieves reliable automatic retraction without requiring extremely tight installation tolerances.
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 system enhances safety by minimizing damage to aircraft components and passengers, reduces the risk of lanyard damage, and allows for targeted protection using airbags, resulting in weight savings and improved crash dynamics.
Implementation Method 1
an arm portion comprising a torsion spring configured to rotatably couple the cargo hook about an axis
Data Source
AI summary
A retractable cargo hook for aircraft is described. The cargo hook comprises a torsion spring allowing rotatable attachment to an aircraft body. An optional recessed portion of the aircraft body can house and receive the cargo hook. This can protect interior components from crashes which can push the cargo hook into the aircraft fuselage, damaging components or even causing post-crash fires.