Aircraft Capture Pin With Freely Rotating Ring for Easy Release
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Solution Overview
Problem
Existing capture pins for aircraft movable elements often seize on spindles, causing friction issues during movement and making it difficult to release, and existing solutions like free-rotating spindles are not satisfactory for inspection and lubrication.
Innovation Solution
A capture pin design featuring a body with a central ring that rotates freely on a central bearing surface, allowing double rotation without the spindle rotating freely, and an auxiliary ring for additional rotation, facilitating inspection and lubrication, with a convex profile and separate materials for improved performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the capture pin body is mounted on a spindle to enable rotation during berthing and release, then the capture pin can roll on the hook, but the capture pin may seize on the spindle causing friction and making it difficult to release
Solution Approach 1:
The capture pin is divided into two independently rotatable components: the body that rotates on the spindle, and the central ring that rotates on the body. This segmentation allows the central ring to continue rolling on the hook even if the body seizes on the spindle, maintaining ease of release while reducing the risk of complete failure.
Solution Approach 2:
The invention introduces a dynamic structure where the central ring can rotate independently on the body, creating a double-rotation system. This dynamic configuration ensures that rotation functionality is maintained at the contact interface with the hook, preventing seizing-related friction issues during operation and release.
2Reliability
If the spindle is allowed to rotate freely to enable capture pin rotation in case of seizing, then rotation is maintained, but it becomes difficult to verify if the spindle is blocked and makes lubrication difficult
Solution Approach 1:
By separating the rotation function into two levels (spindle-body and body-central ring), the invention allows the spindle to remain immobilized for easy inspection while the central ring provides the necessary rotation. This segmentation maintains reliability through double rotation capability without compromising inspection ease.
Solution Approach 2:
Instead of allowing the spindle to rotate freely to maintain rotation capability, the invention inverts the approach by immobilizing the spindle and achieving rotation through the central ring on the body. This reversal solves both the inspection difficulty and lubrication access problems while maintaining rotation functionality.
3Reliability
If the central ring is made of a material adapted to friction and resistant to seizing, then friction is reduced and seizing is prevented, but the device complexity increases due to multiple materials
Solution Approach 1:
The invention applies different material properties to different components: the central ring uses friction-adapted, seizing-resistant material specifically at the critical contact interface with the hook, while the body can use standard materials. This localized quality differentiation reduces seizing risk where it matters most without unnecessarily complicating the entire device with multiple materials.
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 reliable double rotation, simplifies inspection, and allows for effective lubrication, reducing friction and operational difficulties while maintaining spindle immobilization.
Implementation Method 1
The central ring is made of a material adapted to friction and resistant to seizing
Data Source
AI summary
An aircraft landing gear includes a landing gear provided with a yoke supporting a spindle on which is mounted a capture pin to be hooked by a hook of a locking box to be mounted on a structure of an aircraft to immobilize the landing gear in a given position with respect to the structure. The capture pin includes a body provided with a longitudinal opening enabling the capture pin to be mounted on the spindle, and an outer surface of revolution having a central portion having a convex profile to cooperate with the hook. A central portion of the outer surface is formed on a central ring which is mounted so as to rotate freely on a central portion of the body.