Self-locking Aircraft Cargo Restraint with Overrideable Spring Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing cargo restraints for aircraft are prone to damage from contact with cargo and can experience unwanted retraction, leading to disengagement from compatible units during wing flexure, which affects aircraft stability and safety.
Innovation Solution
A vertically adjustable and overrideable cargo restraint system with a locking mechanism that automatically secures in an erect position when engaged by a compatible unit load device, while allowing retraction when overridden by an incompatible one, and includes a spring-loaded head to absorb deck flexure-induced loads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the cargo restraint is made fixed and robust to prevent unwanted retraction during wing flexure, then reliability is improved, but the device complexity and difficulty of manual retraction increase
Solution Approach 1:
The restraint device employs a dynamic locking mechanism that automatically transitions between locked and unlocked states based on engagement conditions. The lock is spring-loaded to automatically engage when the head is in the erect position, and can be automatically disengaged when overridden, providing adaptive behavior rather than a fixed state
Solution Approach 2:
The restraint system is self-actuating through spring-loaded mechanisms that automatically lock the head in the erect position when engaged and automatically retract when overridden. The spring-loaded head provides automatic adjustment to deck flexure without manual intervention, and the self-latching mechanism eliminates the need for continuous manual holding
2Ease of operation
If the cargo restraint is made manually retractable to facilitate cargo loading and unloading, then ease of operation is improved, but the reliability of maintaining engagement during flight is worsened
Solution Approach 1:
The system dynamically adjusts its state based on operational needs. During loading/unloading, the head can be manually overridden to retract. During flight, the spring-loaded locking mechanism automatically engages to maintain reliability. This dynamic behavior resolves the contradiction between ease of operation and engagement stability
3Ease of operation
If the restraint head is made spring-loaded to automatically retract when overridden, then ease of operation is improved, but unwanted retraction during wing flexure occurs reducing reliability
Solution Approach 1:
The locking mechanism provides conditional automatic retraction - it locks when engaged and maintains engagement during normal flight conditions, but automatically retracts when overridden by a ULD or during extreme deck flexure. This dynamic response resolves the contradiction between automatic retraction ease and engagement stability
Solution Approach 2:
The spring-loaded design provides cushioning by allowing controlled movement and energy absorption. The spring can compress to accommodate deck flexure before triggering full retraction, providing a buffer zone that maintains engagement during minor flexure while allowing safe retraction during extreme conditions
4Strength
If the restraint device is made fixed in erect position to prevent damage from contact, then strength is improved, but the ability to adapt to varying cargo configurations is reduced
Solution Approach 1:
The restraint device transitions between fixed (locked in erect position) and movable (retracted) states based on cargo presence and configuration. This dynamic capability allows the device to provide strong fixed restraint when needed for damage resistance, while adapting to different cargo configurations by retracting when not required
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 ensures secure engagement with cargo units, maintains stability during aircraft flexure, and prevents damage by automatically locking in place when compatible units are loaded, while allowing safe retraction from incompatible units, thus enhancing safety and reducing the risk of structural overload.
Implementation Method 1
a spring-loaded head that can pivot between an extended and stowed position
Implementation Method 2
using a locking pin mechanism to secure the head in place when engaged
Data Source
AI summary
An aircraft cargo restraint has a base configured for attachment to a cargo deck. A housing is rotatably mounted to the base about a first axis and is movable between an erect position and a stowed position. A head is movably disposed in the housing, and is movable between an extended position and a contracted position in directions that are substantially parallel to the first axis. The restraint includes a lock configured to releasably secure the housing in the erect position when the head is in the contracted position, and to permit movement of the head from the erect position to the stowed position when the head is in the extended position.