Appliance Mounting Claw with Retractable Pivoting Nut

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Solution Overview

Problem

Existing electrical equipment supports face issues with claw mechanisms that become worn due to constant tension from elastic return means, leading to reduced effectiveness and increased manufacturing costs due to complex production requirements.

Innovation Solution

The electrical equipment support design features a nut that cooperates with a fixed part of the support to push the claw into its retracted position when unscrewing, simplifying the operation and reducing wear, and uses a U-shaped claw with a main wall and legs to anchor into the flush-mounting box, allowing for easier assembly and reduced manufacturing complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If elastic return means (leaf springs) are used to return the claw to the retracted position, then the claw can be automatically returned, but the leaf springs are subject to aging and can break due to constant tension

Engineering Contradiction:
Improveautomatic return of clawVSAvoidleaf spring durability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent removes the elastic return means (leaf springs) from the system entirely. Instead of using elastic components that are subject to aging and failure, the invention uses a purely mechanical return mechanism where the nut itself pushes the claw back to the retracted position through its threaded engagement with the screw, eliminating the unreliable elastic components.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The nut performs a dual function: it not only secures the claw in the deployed position but also actively pushes the claw back to the retracted position when the screw is unscrewed. This self-service mechanism eliminates the need for separate elastic return means, as the fastening component itself provides the return function.

Inventive Principle:
Principle #25Self-service

2Ease of operation

If elastic return means are used to return the claw, then automatic return is achieved, but the leaf springs generate resistant force that complicates installation

Engineering Contradiction:
Improveautomatic return of clawVSAvoidinstallation ease
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

By removing the elastic leaf springs from the system, the patent eliminates the resistant force they generate during installation. The mechanical push-back mechanism created by the nut-screw interaction does not create opposing elastic forces, making installation easier and more straightforward.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If the nut and claw are designed with complex geometries for cooperation, then the return mechanism works reliably, but the manufacturing cost increases

Engineering Contradiction:
Improveclaw return reliabilityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The nut is designed to perform multiple functions: it secures the claw in the deployed position, pushes the claw back to the retracted position, and does so using standard threaded geometry. This multi-functionality with simple, standardized components reduces manufacturing complexity and cost while maintaining reliability.

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

Solution Approach 2:

Instead of using complex elastic components or bevelled surfaces to achieve the return motion, the invention inverts the approach by using the simple threaded engagement of the nut with the screw to create a push-back mechanism. This reverses the conventional wisdom that elastic or bevelled components are needed for return motion.

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

4Reliability

If two separate moving parts (claw and nut) are used for the return mechanism, then the function is achieved, but the assembly complexity and cost increase

Engineering Contradiction:
Improveclaw return functionVSAvoidnumber of moving parts
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the functions of the nut and the return mechanism into a single integrated component. The nut itself becomes the return mechanism through its threaded engagement with the screw, eliminating the need for separate elastic return means or additional moving parts. This reduces assembly complexity and the number of components.

Inventive Principle:
Principle #5Merging (Combining)

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 enhances the reliability and ease of operation by reducing claw wear and lowering manufacturing costs through simplified production and assembly processes.

Implementation Method 1

a screw (70) having a threaded body (72) of longitudinal axis A1 engaged through an opening (11) provided in said frame (10)

Methodology Applied
Scientific EffectScrew mechanism: Screw

Implementation Method 2

a nut (50) screwed onto said threaded body and arranged to bear against a rear face of the claw when screwing the screw in order to tilt said claw from its retracted position to its deployed position

Methodology Applied
Scientific EffectMechanical force transmission: Mechanical Force

Implementation Method 3

a claw (30) articulated around an axis fixed relative to the frame in order to tilt relative to the latter between a retracted position and a deployed position

Methodology Applied
Scientific EffectArticulated rotation: Hinge

Data Source

PatentEP2523284B1Appliance mounting with a prong that can retract under the action of a pivoting nut, electrical appliance including such a mounting
Publication Date: 2014.01.08 LEGRAND FRANCE SA
  • EP2523284B1 patent drawingFigure 1
  • EP2523284B1 patent drawingFigure 2~3
  • EP2523284B1 patent drawingFigure 4~6

AI summary

The support has a nut (50) screwed onto a threaded body. The nut is supported against a rear face of a claw (30) during screwing of a screw (70) so as to tilt the claw from a retracted position to a deployed position. The nut is slid on a ramp (25A) during unscrewing of the screw such that the nut is forced to pivot from an initial position around a longitudinal axis (A1) along rotation direction for pushing the claw from the deployed position to the retracted position. The claw is articulated with respect to a frame (10). The frame, the claw, the nut and the screw are made of a single piece.