Power Take-Off Shaft Locking for Air-Launched Control Surfaces

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Solution Overview

Problem

Surface-launched tactical flight vehicles lack space for conventional control surface locking systems, preventing their repurposing for air-launched applications, and existing solutions involve external devices that interfere with control surfaces.

Innovation Solution

A control surface restraining system that locks the power take-off shafts of the control actuation section, rather than the control surfaces or actuator output shafts, allowing it to be packaged within the existing thrust vector control system space, thus not requiring internal modifications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional control surface locking system is designed into the control actuation section, then the control surfaces can be locked during captive carry, but there is no available space in surface-launched tactical flight vehicles

Engineering Contradiction:
Improvecontrol surface locking capabilityVSAvoidspace in control actuation section
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The locking mechanism is extracted from the internal control actuation section and repositioned to interface with the power take-off shaft that extends outward. This allows the locking system to be implemented without occupying internal space, enabling surface-launched vehicles to be repurposed for air-launched applications.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The power take-off shaft, originally designed for thrust vector control in surface-launched applications, is given dual functionality by serving as the interface point for the control surface locking system in air-launched applications. This multi-functional use eliminates the need for separate locking mechanism space.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Volume of moving object

If external devices are used to lock control surfaces, then space constraints are avoided, but the devices interfere with control surface operation

Engineering Contradiction:
Improvespace availabilityVSAvoidcontrol surface operation
Core Design Contradiction:
Volume of moving objectVSEase of operation

Solution Approach 1:

The power take-off shaft serves as an intermediary element between the control actuation system and the locking mechanism. By locking the shaft rather than directly interfacing with the control surface, the system achieves effective locking while maintaining clear separation between the locking function and control surface operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If the control actuation section is modified to accommodate a locking system, then air-launched capability is enabled, but the existing design is altered

Engineering Contradiction:
Improveair-launched capabilityVSAvoidcontrol actuation section modifications
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The existing power take-off shaft structure serves its original purpose while simultaneously providing the interface needed for the locking system. The shaft's existing geometry and positioning allow it to function as both a drive shaft and a locking interface, eliminating the need for additional modifications to the control actuation section.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4396078B1Control surface locking system for tactical flight vehicle
Publication Date: 2026.03.04 RAYTHEON CO
  • EP4396078B1 patent drawingFigure 1~2
  • EP4396078B1 patent drawingFigure 3~4
  • EP4396078B1 patent drawingFigure 5~6

AI summary

A control surface restraining system for variably preventing movement of a control surface imparted by a control actuation shaft of a control actuation section of a tactical flight vehicle includes a power take-off shaft operably connected to the control actuation shaft with a power take-off gear train and a control surface restraint. The control surface restraint is configured to variably engage the power take-off shaft, thereby locking the power take-off gear train and preventing the control actuation shaft from imparting the movement of the control surface. The control surface restraint is also configured to variably disengage the power take-off shaft, thereby unlocking power take-off gear train and allowing the control actuation shaft from imparting the movement of the control surface.