Bidirectional Wedge Lock Assembly for Radiation-Resistant Joining

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Solution Overview

Problem

Existing assembly mechanisms for mechanical parts in harsh environments, such as nuclear facilities, face reliability issues due to the complexity of screw joints and the degradation of spring-based mechanisms under neutron radiation, leading to operational failures.

Innovation Solution

A bidirectional wedge mechanism comprising a cam and a bolt, where the cam and bolt are housed in bores of the mechanical parts, allowing for translational movement to lock or unlock the assembly, providing a simple and reliable locking system resistant to environmental stresses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If screw joints are used for assembling mechanical parts in nuclear environments, then the assembly can be reversible, but the complexity of implementation increases due to the need for sophisticated robots to handle small screws in confined spaces

Engineering Contradiction:
Improvereversibility of assemblyVSAvoidcomplexity of implementation
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The assembly device is divided into two separate one-piece parts: a cam that fits in a first bore and a bolt that fits in a second bore. This segmentation allows each component to be independently simple in structure while collectively providing the assembly function, eliminating the need for complex multi-part mechanisms or small screws that require sophisticated handling.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of using a traditional screw mechanism that requires rotational movement and precise handling, the invention inverts the approach by using a linear cam-bolt system where the cam translates linearly to drive the bolt. This inversion simplifies the mechanism to basic translational movements that are easier to implement and control.

Inventive Principle:
Principle #13The other way round (Inversion)

2Extent of automation

If spring-based assembly mechanisms are used, then the assembly can be automatic, but the reliability decreases because springs lose elastic properties under neutron radiation

Engineering Contradiction:
Improveautomatic assembly capabilityVSAvoidmechanism reliability under radiation
Core Design Contradiction:
Extent of automationVSReliability

Solution Approach 1:

The invention extracts and eliminates the spring component from the assembly mechanism. By removing the spring, the design avoids the reliability issue of elastic property degradation under neutron radiation while maintaining automatic assembly capability through the cam-bolt translational mechanism driven by external actuation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The cam and bolt are designed as simple, robust, one-piece components that can be replaced if needed, rather than using complex spring mechanisms that degrade over time under radiation. The simplicity of the cam-bolt system makes it more reliable and easier to replace than spring-based mechanisms in harsh nuclear environments.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Productivity

If complex assembly mechanisms with many interacting parts are used, then the assembly function can be achieved, but the reliability decreases due to the unreliability of multiple interacting components

Engineering Contradiction:
Improveassembly function capabilityVSAvoidmechanism reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The invention merges the assembly function into a simple two-component system where the cam and bolt work together through basic translational movement. This consolidation eliminates the need for multiple interacting parts, reducing the number of potential failure points while maintaining the assembly function.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention inverts the traditional approach of using complex multi-part mechanisms by adopting a minimal two-component cam-bolt system. This inversion prioritizes simplicity and reliability over mechanical complexity, achieving the assembly function with the fewest possible components.

Inventive Principle:
Principle #13The other way round (Inversion)

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 assembly device ensures reliable operation even in severe environments by maintaining mechanical strength and simplicity, reducing the need for complex robots and minimizing the impact of radiation on the locking mechanism, thus enhancing safety and operational longevity.

Implementation Method 1

The cam and the bolt each comprise two interaction surfaces forming a wedge system which can be qualified as 'bidirectional' or 'double'. In this case, the interaction surfaces are arranged so that a translational movement of the cam in the first bore, in each direction, causes a translational movement of the bolt in the second and third bores, in a corresponding direction.

Methodology Applied
Scientific EffectWedge mechanism: Wedge

Data Source

PatentEP3670932B1Assembly device of the lock type by means of a mechanism with bidirectional wedges
Publication Date: 2021.09.29 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP3670932B1 patent drawingFigure 1A~1C
  • EP3670932B1 patent drawingFigure 2A~2B
  • EP3670932B1 patent drawingFigure 3A~3B

AI summary

The invention relates to an assembly device between two parts, the first part (30) comprising a cam guide bore (31, 32) and a bolt guide bore (34) extending along non-parallel axes (Z, X), the second part comprising an assembly bore in the extension of the bolt guide bore.According to the invention, the assembly device (1) comprises: ▪ a cam (10) arranged to be able to be moved in translation in the cam guide bore (31, 32), ▪ a bolt (20) arranged to be able to be moved in translation between a locked position, in which it is inserted both in the bolt guide bore (34) and the assembly bore, and an unlocked position, in which it is inserted only in the bolt guide bore (34), the cam and the bolt comprising interaction surfaces arranged to interact so that a displacement of the cam (10) causes a displacement of the bolt (20) towards the locked position or towards the unlocked position.