Avionics Wedge With Elastomer Inserts For Thermal And Wear Management

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Solution Overview

Problem

Existing wedges used in avionics for securing electronic modules in receptacles suffer from slippage, wear, corrosion, and jamming issues due to their material and design, leading to poor support and thermal management.

Innovation Solution

A wedge system with a flexible material skeleton and elastomer inserts, coupled with a bistable lever actuator, that retracts from the interface zone to reduce jamming and wear, and features guide pins to prevent lateral movement, ensuring reliable clamping and thermal management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If traditional aluminum wedges with rigid structure are used, then thermal conductivity is improved, but wear and corrosion resistance deteriorate

Engineering Contradiction:
Improvethermal conductivityVSAvoidwear and corrosion resistance
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The wedge is constructed as a composite structure combining an aluminum skeleton (rigid, thermally conductive) with elastomer inserts (flexible, wear-resistant). The aluminum provides thermal management while the elastomer protects against wear and corrosion at the interface with the module and receptacle.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

Different parts of the wedge have different material properties: the skeleton is rigid aluminum for structural support and thermal conduction, while the inserts are flexible elastomer for wear resistance and non-sticking properties. Each material is placed where its specific properties are most needed.

Inventive Principle:
Principle #3Local quality

2Strength

If rigid wedge segments are used, then structural strength is improved, but slippage and wear increase

Engineering Contradiction:
Improvestructural strengthVSAvoidslippage and wear
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The wedge combines rigid aluminum skeleton with flexible elastomer inserts. The elastomer inserts prevent slippage between wedge segments and reduce wear at contact surfaces, while the aluminum skeleton maintains overall structural strength and rigidity.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The wedge transitions from entirely rigid segments to a hybrid structure where the elastomer inserts change the friction and compliance parameters at critical interfaces, reducing slippage and wear while maintaining load-bearing capacity through the aluminum skeleton.

Inventive Principle:
Principle #35Parameter changes

3Force

If wedge material is highly frictional, then gripping capability is improved, but jamming risk increases

Engineering Contradiction:
Improvegripping capabilityVSAvoidjamming risk
Core Design Contradiction:
ForceVSEase of operation

Solution Approach 1:

The elastomer inserts change the friction parameter at the interface between the wedge and the module/receptacle. The elastomer provides controlled friction for gripping while its flexible nature prevents excessive adhesion that would cause jamming, allowing smooth insertion and removal.

Inventive Principle:
Principle #35Parameter changes

4Strength

If wedge segments are made of metal, then strength is improved, but corrosion and metal dust production increase

Engineering Contradiction:
ImprovestrengthVSAvoidcorrosion and metal dust
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The wedge uses an aluminum skeleton for strength combined with elastomer inserts that protect the metal from direct contact with the module and receptacle surfaces. This prevents corrosion and eliminates metal dust production at the interface, while the aluminum skeleton maintains the necessary structural strength.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The elastomer inserts act as an intermediary layer between the metal wedge skeleton and the module/receptacle surfaces. This intermediary prevents direct metal-to-metal contact, thereby preventing corrosion and metal dust generation while still transmitting the necessary clamping force.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 wedge system provides reliable, low-friction clamping with reduced risk of corrosion and jamming, effective thermal management, and absorbs shocks and vibrations, ensuring stable module support and efficient heat dissipation.

Implementation Method 1

a wedge element (19) mounted on the plate (13), this wedge element (19) having a second upper bearing face (20), facing opposite the first bearing surface (14) and intended to be applied against the first side wall (10) of the receptacle (2) (or, at the installer's choice, against the side face (15) of the module (3))

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the longitudinal compression of the wedge (i.e. the bringing together of its two ends under the operation of its actuator) causing the sliding and the overlap of the wedge segments relative to each other, and hence the transverse expansion of the wedge

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 3

This last property is useful for the evacuation of the calories generated in the module following the heating of the circuits, these being initially transmitted to the bay via the hold

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP1886545B1Expandable wedge and system comprising a module, a receptacle and such a wedge interposed between them
Publication Date: 2008.07.16 SAFRAN ELECTRONICS & DEFENSE SAS
  • EP1886545B1 patent drawingFigure 1
  • EP1886545B1 patent drawingFigure 2
  • EP1886545B1 patent drawingFigure 3

AI summary

The invention concerns a wedge (12) comprising: a plate (13), and actuator (16) mounted on the plate (13) while being mobile relative thereto between an active position and an inactive position; a wedge element (19) mounted on the plate (13) and coupled to said actuator (16), said wedge element (19) being deformable between: an inactive configuration, adopted in inactive position of the actuator (16), wherein the wedge element (19) extends in the vicinity of the plate (13), and an active configuration, adopted in the active position of the actuator (16), wherein the wedge element (19) is in straight position while being at least locally spaced apart from the plate (13). The invention also concerns a system comprising a module, a receptacle and such a wedge interposed between them.