Retractable Pintle Pin Assembly for Aircraft Strut Joints
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Solution Overview
Problem
Aircraft landing gear assemblies with pintle-type joints face challenges in being removable or detachable due to limited access, which complicates assembly and disassembly, and existing solutions either weaken the structure or provide insufficient access.
Innovation Solution
A retraction mechanism using a leadscrew, cam and follower, or lever mechanism allows the pintle pins to be moved between extended and retracted positions within the tubular structure, enabling disengagement from connection points for assembly and disassembly without compromising structural integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If pintle pins are removed completely to permit assembly and disassembly, then ease of assembly is improved, but device complexity and risk of loss increase
Solution Approach 1:
The pintle pin is nested within the tubular structure during storage and transport. The retainer mechanism allows the pin to be contained within the tube when not in use, and selectively positioned outward when assembly is required, eliminating the need for complete removal while maintaining ease of assembly/disassembly operations
2Ease of operation
If pintle pins are fitted from the inside of the tubular structure via a cut away or slot, then accessibility is improved, but structural strength deteriorates
Solution Approach 1:
The tubular structure is segmented into distinct functional zones: a reinforced pintle socket region that maintains full structural integrity, and a separate access region with an opening that provides tool access for the retainer mechanism. This segmentation allows the socket to remain strong while enabling internal access for pin manipulation
3Strength
If pintle pins are fitted from the outside by lining up pintle lug with pintle socket, then structural integrity is maintained, but accessibility is insufficient
Solution Approach 1:
The retainer mechanism acts as an intermediary tool that bridges the gap between the limited external access and the internal pin positioning requirement. It provides the necessary leverage and mechanical advantage to manipulate the pin from within the tubular structure, eliminating the need for extensive external access while maintaining structural integrity
4Ease of operation
If a retraction mechanism is implemented to move pins between extended and retracted positions, then ease of assembly and disassembly is improved, but device complexity increases
Solution Approach 1:
The retainer mechanism is designed to be manually operated by the user without requiring additional power sources, complex control systems, or specialized tools. The simple manual actuation provides self-service functionality that achieves ease of assembly and disassembly while minimizing the addition of complex mechanism
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 efficient and accessible assembly and disassembly of aircraft landing gear assemblies by allowing the pintle pins to be retracted within the tubular structure, improving accessibility and maintaining structural strength.
Implementation Method 1
A retraction mechanism using a leadscrew, cam and follower, or lever mechanism allows the pintle pins to be moved between extended and retracted positions within the tubular structure
Implementation Method 2
A retraction mechanism using a leadscrew, cam and follower, or lever mechanism allows the pintle pins to be moved between extended and retracted positions within the tubular structure
Implementation Method 3
A retraction mechanism using a leadscrew, cam and follower, or lever mechanism allows the pintle pins to be moved between extended and retracted positions within the tubular structure
Data Source
Figure 1
Figure 2A~2B
Figure 3~4B
AI summary
The invention provides an attachment assembly for an aircraft joint, and in particular for a strut mounting joint. The attachment assembly comprises a tubular structure having a central axis (PA) and at least one open end. The attachment assembly further comprises at least one mounting pin (560a, 560b) 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 from the at least one open end of the tubular structure for engagement with a lug and in the retracted position the at least one mounting pin is withdrawn into the tubular structure for disengagement with the lug. The attachment assembly further comprises a retraction mechanism disposed within the tubular structure and coupled to the at least one mounting pin, the 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.