Actuator Lock Biasing Mechanism to Prevent Premature Sleeve Locking
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Solution Overview
Problem
The tine lock and lock sleeve in an actuator for a thrust reverser often fail to return to a stowed and locked position correctly, leading to false signaling due to the lock sleeve inadvertently returning to the locked position before the door is fully stowed, causing the tine lock to be unable to engage.
Innovation Solution
A biasing system comprising a lock sleeve, lock shaft, tine finger, biasing member, and biasing spring is used to maintain the tine finger away from the longitudinal axis during deployment, preventing the lock sleeve from returning to a locked position until the lock shaft is fully returned, ensuring accurate engagement and stowing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the lock sleeve is allowed to return freely to the locked position, then the locking action is simple and quick, but the lock sleeve may return prematurely before the door is fully stowed, causing false signaling and inability of the tine lock to engage
Solution Approach 1:
The biasing spring is pre-compressed during the deployment of the lock shaft, storing energy that will later bias the tine finger against the lock sleeve. This preliminary action ensures that when the lock sleeve returns, the tine finger is already positioned to prevent premature locking, resolving the contradiction between simple return motion and reliable accurate locking.
Solution Approach 2:
The biasing member acts as an intermediary between the lock shaft and the tine finger, transferring the biased force from the spring to the tine finger. This intermediary mechanism allows the complex biasing function to be integrated into the existing locking mechanism without requiring a completely new system, thus managing device complexity while achieving reliable locking.
2Reliability
If the tine finger is maintained away from the longitudinal axis during deployment, then premature locking is prevented, but the biasing mechanism requires additional components and space
Solution Approach 1:
The biasing spring is nested within the existing actuator structure, utilizing the hollow cylindrical space of the lock shaft. The spring is positioned concentrically within the lock shaft, and the biasing member connects the spring to the tine finger, allowing the biasing mechanism to occupy minimal additional volume while effectively maintaining the tine finger away from the longitudinal axis during deployment.
3Productivity
If the lock shaft and lock sleeve are deployed simultaneously, then the deployment process is efficient, but the lock sleeve cannot be prevented from returning before the lock shaft is fully retracted
Solution Approach 1:
The biasing spring is pre-compressed during the deployment phase, storing energy that creates a counteracting force during the return phase. This preliminary anti-action ensures that when the lock sleeve returns, the biased tine finger is already positioned to prevent the lock sleeve from returning to the locked position before the lock shaft is fully retracted, thus maintaining sequential return control without compromising deployment efficiency.
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 biasing system ensures reliable and accurate locking and unlocking of the actuator, preventing false signaling and enhancing system reliability by maintaining the lock sleeve in an intermediate position until the lock shaft is fully returned, thus avoiding premature locking.
Implementation Method 1
a biasing spring (140) configured to bias the biasing member (142) in a first direction
Data Source
AI summary
A biasing system for an actuator. The system includes a lock sleeve, a lock shaft, a tine having a tine finger extending along a longitudinal axis, a biasing member and a biasing spring. The biasing member and biasing spring are configured to maintain a position of the tine finger away from the longitudinal axis in the direction of the lock sleeve when the lock shaft and the lock sleeve are deployed, in use, such that, when the lock sleeve is returned, the tine finger is biased against the lock sleeve to prevent the lock sleeve from returning to a locked position before the lock shaft is able to return to a locked position.