Multi-Stage Drive Mechanism for Control Surface Deployment and Precision

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Solution Overview

Problem

Conventional drive mechanisms for control surfaces, such as canards, are complex and costly, requiring multiple energy sources and gear ratios for deployment and control, which complicates the output shaft and support structure.

Innovation Solution

A multi-stage drive mechanism using a linear actuator for movement along an actuation axis, with a lock system that allows rotation about different axes for deployment and control stages, featuring a link with a swivel cap and catch mechanism to manage axis rotations efficiently.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a small gear ratio is used for fast canard deployment, then deployment speed is improved, but control precision deteriorates

Engineering Contradiction:
Improvedeployment speedVSAvoidcontrol precision
Core Design Contradiction:
SpeedVSMeasurement precision

Solution Approach 1:

The patent divides the control process into two distinct stages: deployment stage and control stage. During deployment, the canard rotates about the deployment axis with prioritized speed. During control, the canard rotates about the control axis with prioritized precision. This segmentation allows each stage to use optimized gear ratios without compromise.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs dynamic switching between different gear ratios through the lock mechanism. The first lock engages during deployment to provide small gear ratio for speed, then disengages and the second lock engages during control to provide large gear ratio for precision. This dynamic reconfiguration resolves the contradiction between speed and precision requirements.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If a high gear ratio is used for accurate canard control, then control precision is improved, but deployment speed deteriorates

Engineering Contradiction:
Improvecontrol precisionVSAvoiddeployment speed
Core Design Contradiction:
Measurement precisionVSSpeed

Solution Approach 1:

The patent segments the operational requirements into deployment phase (requiring speed) and control phase (requiring precision). By providing separate lock mechanisms for each phase, the system can select appropriate gear ratios for each segment, avoiding the compromise that would result from using a single fixed gear ratio.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically switches between gear ratios by engaging different locks at different operational phases. The first lock provides high gear ratio for precise control when engaged, while the second lock provides low gear ratio for fast deployment. This dynamic adaptation eliminates the trade-off between speed and precision.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If the canard and support structure rotate about the control axis, then control function is achieved, but structural complexity increases due to slot in output shaft

Engineering Contradiction:
Improvecontrol functionVSAvoidstructural complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent separates the rotation functions into two independent rotational movements: deployment rotation about the deployment axis, and control rotation about the control axis. This segmentation allows each rotation to be achieved through dedicated mechanical paths, eliminating the need for complex slots in the output shaft that would be required if both functions shared a single rotation path.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces intermediate linkages and lock mechanisms that mediate between the actuator and the canard. These intermediaries translate linear actuator movement into the two distinct rotational movements required, avoiding the need for direct complex coupling between the actuator and canard that would require slots in the output shaft.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2796828B1Multi-stage drive mechanisms
Publication Date: 2017.09.06 SIMMONDS PRECISION PRODUCTS INC
  • EP2796828B1 patent drawingFigure 1~2
  • EP2796828B1 patent drawingFigure 3~7
  • EP2796828B1 patent drawingFigure 5~6

AI summary

A multi-stage drive (100) includes a linear actuator (104) configured for linear movement along an actuation axis, and a control surface (102). The control surface is operatively connected to the linear actuator for rotation about a deployment axis (B) in a deployment stage, and for rotation in a control stage about a control axis (C) that is different from the deployment axis, so that movement of the linear actuator along the actuation axis drives rotation of the control surface in both the deployment stage and in the control stage.