Retractable Pintle Pin Assembly for Limited-Access Landing Gear Joints
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Solution Overview
Problem
Existing aircraft landing gear assemblies with pintle-type joints face challenges in being removable or detachable from the aircraft structure due to limited access, which complicates assembly and disassembly.
Innovation Solution
An attachment assembly with a tubular structure and moveable mounting pins, equipped with a retraction mechanism that converts rotary input motion into linear motion, allowing the pins to be retracted for disengagement and extended for engagement with lug connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pintle pins are protruding from pintle sockets and engaged with pintle lugs, then the joint provides structural connection and load-bearing capability, but the landing gear assembly cannot be detached from the aircraft structure
Solution Approach 1:
The pintle pin is designed with dynamic positioning capability, allowing it to switch between an extended position (protruding from the socket for engagement with the lug) and a retracted position (withdrawn into the socket for disengagement). This dynamic repositioning enables the joint to transition between connected and detached states, resolving the contradiction between maintaining reliable connection and enabling detachability.
2Adaptability or versatility
If pintle pins are removed completely to permit assembly and disassembly, then the joint can be assembled and disassembled, but there is insufficient access outside the ends of the aircraft pintle lugs to insert the pins
Solution Approach 1:
The pintle pin is nested within the tubular structure during storage and transport. The pin can be extended from the tubular structure to engage with the lug, and retracted back into it for disengagement. This nesting arrangement solves the accessibility problem by allowing the pin to be inserted from within the tubular structure rather than requiring external access, while still enabling assembly and disassembly operations.
3Ease of operation
If pins are fitted from the inside of the tubular structure via a cut away or slot, then the pins can be inserted into mounting positions, but this reduces the strength of the pintle socket area or other part of the main fitting
Solution Approach 1:
The attachment assembly is segmented into distinct functional components: the tubular structure, the pintle pin, and the retraction mechanism. This segmentation allows the pin to be inserted from the inside of the tubular structure without requiring large cutaways or slots, as the pin can be guided through a more compact path. The segmentation enables pin insertion while preserving the structural integrity and strength of the pintle socket area.
4Adaptability or versatility
If a retraction mechanism is added to convert rotary input motion into linear motion of the mounting pin, then the pin can be retracted for disengagement and extended for engagement, but the device complexity increases
Solution Approach 1:
The retraction mechanism replaces complex mechanical systems with a simpler screw-thread based system. The screw-thread mechanism converts rotary input motion directly into linear motion of the pintle pin, eliminating the need for more complex linkages, cams, or hydraulic systems. This substitution achieves the required pin retraction and extension capability while minimizing the increase in device complexity.
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
Enables the aircraft landing gear assembly to be easily assembled and disassembled by retracting the pins, overcoming the limitations of pintle-type joints with limited access, and improving operational efficiency.
Implementation Method 1
a retraction mechanism arranged to convert a rotary input motion into linear motion of the at least one mounting pin along the central axis to drive the at least one mounting pin between the extended position and the retracted position
Data Source
AI summary
An attachment assembly for an aircraft strut mounting joint. The attachment assembly includes a tubular structure having a central axis and at least one open end. The attachment assembly further includes at least one mounting pin arranged at least partially within the at least one open end of the tubular structure and moveable along the central axis between a retracted position and an extended position. In the extended position, a portion of the at least one mounting pin protrudes for engagement with a lug and in the retracted position the at least one mounting pin is withdrawn for disengagement with the lug. The attachment assembly further includes a retraction mechanism arranged to convert a rotary input motion into linear motion of the at least one mounting pin along the central axis to drive the at least one mounting pin between the extended position and the retracted position.