Passive Landing Gear Uplock Mechanism Without Hydraulics
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Solution Overview
Problem
Conventional aircraft uplock mechanisms for landing gear are complex and heavy due to their reliance on hydraulic systems, which can complicate design and increase weight, necessitating a simpler and lighter solution for locking landing gear in a stowed position during flight.
Innovation Solution
A passive uplock system utilizing a combination of biasing members, including springs, a hook, and a cam mechanism, along with a manual release system and safety blocking mechanism, to securely lock and unlock the landing gear without the need for hydraulic actuation, providing a lightweight and simplified design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hydraulic actuation systems are used for uplock mechanisms, then the landing gear can be locked and unlocked, but the system becomes complex and heavy
Solution Approach 1:
The patent removes the hydraulic actuation system from the uplock mechanism, extracting the complex hydraulic components while retaining the essential locking function through a purely mechanical passive system that uses spring biasing and cam-follower geometry
Solution Approach 2:
The uplock system is designed to be self-actuating, where the landing gear weight itself drives the hook along the cam surface during retraction, automatically engaging the uplock without requiring external hydraulic power
2Reliability
If hydraulic actuation systems are used for uplock mechanisms, then the landing gear can be locked and unlocked, but the system weight increases
Solution Approach 1:
The patent removes the hydraulic actuation system from the uplock mechanism, extracting the complex hydraulic components while retaining the essential locking function through a purely mechanical passive system that uses spring biasing and cam-follower geometry
Solution Approach 2:
The system uses spring biasing members that provide a counteracting force to the landing gear weight, allowing the hook to be held in the locked position without requiring continuous hydraulic pressure, thereby reducing the overall system weight
3Device complexity
If conventional spring loaded catch systems are used, then the system is simpler, but the weight carrying capacity is insufficient
Solution Approach 1:
The patent employs a cam surface with specific curvature that converts the vertical landing gear weight into a horizontal force component that drives the hook along the cam, enabling the simple spring-loaded system to securely carry the full landing gear weight during retraction and stowage
Solution Approach 2:
The patent combines the spring-loaded catch mechanism with a cam-follower system, merging the simplicity of spring actuation with the mechanical advantage of cam geometry to achieve both structural simplicity and adequate weight carrying capacity
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 effectively locks and unlocks the landing gear efficiently, reducing overall weight and part count, while ensuring safety through the safety blocking mechanism, thereby enhancing aircraft performance and reducing complexity.
Implementation Method 1
a first biasing member, the first biasing member configured to bias the hook in a first rotational direction
Implementation Method 2
a second biasing member, in response to the latchable member moving in a third direction, the second biasing member rotating the following member in the first rotational direction
Implementation Method 3
a third biasing member, in response to the hook moving from the second stable position to the first stable position, the third biasing member rotating the following member in the second rotational direction
Implementation Method 4
a cam, a following member, in response to the hook moving from the second stable position to the first stable position, the following member configured to engage the cam in response to the member moving in a fourth direction
Data Source
Figure 1A~1B
Figure 2~3A
Figure 3B~3C
AI summary
Systems and methods for uplock systems are provided. An uplock system may comprise a body (14), a hook (12) having an opening defining at least a first surface and a second surface, the hook (12) being rotationally engaged with the body (14), a first biasing member (22) configured to bias the hook (12) in a first rotational direction relative to the body (14), and a cam (18) in operable communication with the hook (12) and the body (14) such that the hook (12) has at least a first stable position and a second stable position relative to the body (14) when biased in the first rotational direction.