Passive Aircraft Uplock Hook Mechanism for Reliable Gear Stowage
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Solution Overview
Problem
Conventional aircraft uplock mechanisms are complex and heavy due to their reliance on hydraulic systems, which complicates their design and functionality, necessitating a simpler and lighter solution for locking landing gear in a stowed position during flight.
Innovation Solution
A passive uplock system utilizing a hook with biasing members and a cam mechanism, allowing for rotational movement between stable positions, coupled with a manual release system and safety blocking mechanism, to securely lock and unlock the landing gear without hydraulic actuation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hydraulic actuation systems are used for uplock mechanisms, then reliable locking and unlocking function is achieved, but device complexity and weight increase
Solution Approach 1:
The patent extracts and removes the hydraulic actuation system from the uplock mechanism, replacing it with a purely mechanical passive system. The hydraulic components (pumps, valves, fluid lines) are completely eliminated, leaving only mechanical elements like springs, cams, and levers that work together through mechanical advantage and energy storage principles.
Solution Approach 2:
The uplock mechanism is designed to be self-operating using passive mechanical components. The system uses spring-loaded catch systems that automatically engage and disengage based on mechanical interactions with the landing gear structure, eliminating the need for external hydraulic power sources and control systems.
2Reliability
If hydraulic actuation systems are used for uplock mechanisms, then reliable locking and unlocking function is achieved, but weight increases
Solution Approach 1:
The patent extracts and removes the hydraulic actuation system from the uplock mechanism, replacing it with a purely mechanical passive system. The hydraulic components (pumps, valves, fluid lines) are completely eliminated, leaving only mechanical elements like springs, cams, and levers that work together through mechanical advantage and energy storage principles.
Solution Approach 2:
The uplock mechanism is designed to be self-operating using passive mechanical components. The system uses spring-loaded catch systems that automatically engage and disengage based on mechanical interactions with the landing gear structure, eliminating the need for external hydraulic power sources and control systems.
3Device complexity
If conventional spring loaded catch systems are used, then simplicity is improved, but reliability in inverted flight conditions deteriorates
Solution Approach 1:
The patent incorporates cam mechanisms with curved surfaces that provide mechanical advantage in multiple directions. The cam profiles are designed to maintain proper engagement geometry regardless of the aircraft's orientation, ensuring reliable locking and unlocking forces whether the aircraft is in normal or inverted flight.
Solution Approach 2:
The uplock mechanism uses multiple spring-loaded catch systems with adjustable spring forces and geometric parameters. These parameters can be optimized to provide sufficient locking force in all flight orientations, including inverted flight, while maintaining system simplicity through the passive mechanical 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 system provides a lightweight, simplified mechanism for locking and unlocking aircraft landing gear, reducing overall weight and part count while ensuring reliable operation and safety, even in inverted flight conditions.
Implementation Method 1
a first biasing member configured to bias the hook in a first rotational direction relative to the body
Implementation Method 2
a cam in operable communication with the hook and the body such that the hook has at least a first stable position and a second stable position relative to the body when biased in the first rotational direction
Data Source
AI summary
A method of operating an uplocking system includes contacting with a latchable member a first surface of an opening of a hook biased in a first rotational direction relative to a body, rotating the hook in a second rotational direction with the contacting, moving the hook out of a first position relative to the body, rotating the hook in the first rotational direction after release of the contacting with the latchable member, moving the hook into a second position relative to the body, the first position and the second position being stable when the hook is biased in the first rotational direction without contact being made against the first surface, and retaining the latchable member with a second surface of the hook when the hook is in the second position.