Ammunition Control Surfaces Using Elastic Sheet Nesting

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Solution Overview

Problem

Conventional ammunition piloting devices with control surfaces are bulky and complex, reducing the payload volume, especially in sub-munitions dispersed by artillery cargo shells, due to the need for extensive motorization and deployment mechanisms.

Innovation Solution

The piloting device integrates control surfaces formed of elastic sheets that fold around the ammunition body, using a geared motor system with a conical rack and pinion mechanism, allowing compact and robust control surface deployment and control, with four geared motors driving the control surfaces in a compact configuration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional control surfaces with extensive motorization are used, then control functionality is achieved, but the device becomes bulky and payload volume is reduced

Engineering Contradiction:
Improvecontrol functionalityVSAvoidpayload volume
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The control surfaces are folded and nested around the rear part of the ammunition body during storage, similar to a nested doll structure. The elastic sheets wrap around the body in a compact configuration, and only deploy to their functional position when needed, maximizing payload volume while maintaining control capability.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The control surfaces transition from a static folded state to a dynamic deployed state through the action of geared motors. The elastic sheets are designed to be flexible and deformable, allowing them to change shape and position dynamically during flight control operations.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If conventional deployment mechanisms are used, then control surfaces can be deployed, but the device complexity increases

Engineering Contradiction:
Improvecontrol surface deploymentVSAvoidmechanism complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The deployment and control functions are merged into a single integrated mechanism. The geared motors serve dual purposes: they deploy the control surfaces from their folded position and also control their pivoting movement for trajectory adjustment, eliminating the need for separate deployment and control mechanisms.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The control surfaces are made from elastic sheets that are flexible and can be folded around the ammunition body. This flexible film approach replaces rigid control surfaces with complex hinges and joints, significantly simplifying the overall mechanism while maintaining deployment and control capabilities.

Inventive Principle:
Principle #30Flexible shells and thin films

3Ease of operation

If control surfaces are arranged inside the ammunition body, then deployment is achieved, but the device becomes bulky

Engineering Contradiction:
Improvecontrol surface deploymentVSAvoiddevice volume
Core Design Contradiction:
Ease of operationVSVolume of stationary object

Solution Approach 1:

The control surfaces utilize the radial dimension around the ammunition body for their folded storage configuration. Instead of occupying internal volume, they wrap around the exterior rear part of the body, effectively using the circumferential space that would otherwise be unused, thereby minimizing the device's overall volume footprint.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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

This design minimizes bulk and complexity, allowing for efficient use of space within the ammunition, enabling effective control surface deployment and control while maintaining a significant payload volume, particularly suitable for sub-munitions.

Implementation Method 1

the control surfaces are formed of elastic sheets that can be folded by winding around a rear part of the body of the ammunition and capable of unwinding to adopt a substantially radial position

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP1953494B1Device for controlling ammunition with deployable control surfaces
Publication Date: 2010.05.26 NEXTER MUNITIONS SA
  • EP1953494B1 patent drawingFigure 1~2a
  • EP1953494B1 patent drawingFigure 2b
  • EP1953494B1 patent drawingFigure 3~4

AI summary

The device has a control surface (9) placed in a body of an ammunition. The surface is formed by elastic sheets that are folded by rolling around a back part (12) of the ammunition body and are unrolled to adopt a radial position with respect to the body. The surface includes a support (11) carrying the sheets formed in a plane of the surface. The support is articulated with respect to the body at level of a pivot (14) that is placed in front of the surface plane. The support carries a back toothed conical rack (15) intermeshed on a pinion (16) driven by a controlling gear motor.