Toggle-Jaw Cable Clamp Layout to Reduce Corona Effects

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Solution Overview

Problem

Existing clamping devices for overhead electrical cables under high voltage (above 60 kV) suffer from inappropriate placement of the axis of the pivoting connection between the lever and the second jaw, leading to accumulation of electric fields or charges, which can cause ionization and radio disturbances.

Innovation Solution

A clamping device design with a toggle connection between the lever and the second jaw, where the support, first jaw, and lever form a compact shape with convex external surfaces, ensuring no elements are outside the cable volume, thus preventing field and charge accumulation, and using a connecting rod with pivoting connections to maintain the second jaw in a closed position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the axis of the pivoting connection between the lever and the second jaw is placed outside the volume delimited by electric cables, then the clamping device can achieve a simple structure and easy operation, but electric charges and electric fields accumulate at these external elements, causing corona effects and radio disturbances

Engineering Contradiction:
Improvestructure simplicityVSAvoidcorona effect and radio disturbances
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent applies the nesting principle by placing all moving elements (lever, connecting rod, second jaw with pivoting connections) inside the support structure. The support acts as a container that houses these components, ensuring they remain within the volume delimited by the electric cables. This nested arrangement eliminates external protruding elements that would otherwise cause charge accumulation and corona effects, while still allowing the clamping mechanism to function with adequate clearance for cable insertion and toggling motion.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Ease of manufacture

If elements with sharp edges are exposed on the clamping device, then manufacturing and assembly are simplified, but these sharp edges become sites for accumulation of electric fields and charges

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidelectric field accumulation
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent applies the spheroidality principle by specifying that all external surfaces of the support, jaws, and lever that face the electric cables must have a convex curvature with a radius of at least 5 mm. This curvature requirement eliminates sharp edges and corners on the external surfaces, preventing charge accumulation and corona effects. The internal elements may retain sharp edges for manufacturing simplicity, but these are hidden inside the support and do not interact with the high-voltage cables.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Object-affected harmful factors

If the clamping device has a compact shape with all elements housed inside the support, then field and charge accumulation is minimized, but the device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvefield and charge accumulationVSAvoidstructural complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent applies the nesting principle by placing all moving elements (lever, connecting rod, second jaw with pivoting connections) inside the support structure. The support acts as a container that houses these components, ensuring they remain within the volume delimited by the electric cables. This nested arrangement eliminates external protruding elements that would otherwise cause charge accumulation and corona effects, while still allowing the clamping mechanism to function with adequate clearance for cable insertion and toggling motion.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent applies the spheroidality principle by specifying that all external surfaces of the support, jaws, and lever that face the electric cables must have a convex curvature with a radius of at least 5 mm. This curvature requirement eliminates sharp edges and corners on the external surfaces, preventing charge accumulation and corona effects. The internal elements may retain sharp edges for manufacturing simplicity, but these are hidden inside the support and do not interact with the high-voltage cables.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 solution effectively clamps electrical cables without external elements that could accumulate electric fields or charges, reducing corona effects and air ionization, while maintaining a compact shape to minimize field and charge accumulation.

Implementation Method 1

the second jaw is locked, and cooperates with the first jaw to clamp an elongated conductor

Methodology Applied
Scientific EffectToggle effect: Mechanical Advantage

Data Source

PatentEP4311051A1Clamping device for fixing a spacer to an elongate conductor and spacer comprising several units of such a clamping device
Publication Date: 2024.01.24 DERVAUX
  • EP4311051A1 patent drawingFigure 1~2
  • EP4311051A1 patent drawingFigure 3~4
  • EP4311051A1 patent drawingFigure 5~6

AI summary

The invention relates to a clamping device for fixing a long conductor to a spacer, the clamping device (101) comprising: a support (110) including a connecting member (120) to a spacer, a first jaw (131) integral with the support, a second jaw (132) connected to the support by a pivoting connection about a first axis (137), a lever (134) connected to the support by a pivoting connection about a second axis (138), a connecting rod (135) connected to the lever and to the second jaw respectively by pivoting connections about third and fourth axes (136, 139), the connecting rod forming a toggle joint between the lever and the second jaw, so that the second jaw is movable relative to the support between: an open position in which the long conductor can be inserted between the two jaws, and a closed position in which the second jaw is locked.