Screwless Clamping Device for Conductors with Back-to-Back Spring Legs

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Solution Overview

Problem

Existing screwless clamp devices for electrical conductors, particularly lightning protection and grounding conductors, face challenges in securely connecting conductors with different cross-sectional areas and maintaining effective electrical contact, especially with rough surfaces like concrete reinforcement steel, while being cost-effective and easy to manufacture.

Innovation Solution

A screwless clamping device comprising two parts with spring legs that can be connected back-to-back, allowing for secure contact of conductors with various cross-sectional areas, including round and flat conductors, through a combination of spring legs and a stabilizing web, ensuring high surface pressure and effective lightning impulse current carrying capacity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If spring-loaded claws are used to clamp the conductor, then the clamping force is provided, but the electrical contact quality deteriorates due to insufficient surface pressure on rough conductors like reinforcement steel

Engineering Contradiction:
Improveclamping forceVSAvoidelectrical contact quality
Core Design Contradiction:
ForceVSReliability

Solution Approach 1:

The patent combines the mechanical clamping function and electrical conduction function into a single integrated clamp body. The clamp includes both clamping elements (for mechanical force) and conductive elements (for electrical conduction), merging two separate functions that were previously performed by separate components. This integration ensures that the clamping force is directly applied at the electrical contact points, improving contact quality while maintaining adequate clamping force.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The clamp features locally optimized contact surfaces with increased surface area specifically at the electrical contact regions. The conductive elements are designed with enlarged contact surfaces that locally concentrate the clamping force, providing sufficient surface pressure for reliable electrical contact on rough conductors while the overall clamp structure maintains appropriate clamping force distribution.

Inventive Principle:
Principle #3Local quality

2Reliability

If multiple separate components are used to ensure adequate electrical contact, then the electrical connection quality improves, but the device complexity and manufacturing cost increase

Engineering Contradiction:
Improveelectrical connection qualityVSAvoidnumber of parts
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent integrates multiple functions into a single clamp component. The clamp body simultaneously provides mechanical support, clamping force through spring-loaded elements, and electrical conduction through integrated conductive elements. This eliminates the need for separate contact pieces, connection elements, and fasteners, reducing part count while maintaining reliable electrical connection quality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The clamp is designed as a multi-functional component that performs mechanical clamping, provides electrical conduction, and ensures adequate contact pressure all through a single element. The integrated design allows the same component to fulfill multiple roles that would traditionally require separate parts, simplifying the overall assembly and reducing complexity.

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

3Reliability

If the clamp is designed for specific conductor types, then the contact quality for that type is optimized, but the adaptability to different conductor cross-sections is reduced

Engineering Contradiction:
Improvecontact qualityVSAvoidconductor cross-section compatibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The clamp incorporates spring-loaded clamping elements that provide dynamic adaptability to different conductor sizes and shapes. The spring mechanism automatically adjusts the clamping force and contact pressure based on the conductor's dimensions, allowing the same clamp design to effectively contact various conductor cross-sections while maintaining adequate electrical contact quality through localized surface pressure enhancement.

Inventive Principle:
Principle #15Dynamics

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 device provides a cost-effective, simple, and versatile solution for securely connecting conductors with different cross-sectional areas, ensuring reliable electrical contact and efficient lightning impulse current handling, without the need for multiple parts or complex assembly.

Implementation Method 1

spring-loaded claws projecting from the support part

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

spring legs that can be connected back-to-back

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP3404772B1Screwless clamping device for electric conductors
Publication Date: 2022.08.31 DEHN SOHNE GMBH CO KG
  • EP3404772B1 patent drawingFigure 1a
  • EP3404772B1 patent drawingFigure 1b
  • EP3404772B1 patent drawingFigure 2a

AI summary

The invention relates to a screwless clamping device for electrical conductors, in particular lightning protection or earthing conductors with the same or different cross-sectional areas, consisting of at least two opposing spring legs made of electrically conductive material, forming a spring leg pair and having a shape for receiving and contacting a section of the respective electrical conductor, as well as a connecting section between the spring legs. According to the invention, a first clamping part with at least two spring legs and a second clamping part with at least two spring legs are provided, wherein the respective connecting sections between the spring legs are arranged back-to-back and connectable.