W-Shaped Spring Clamp for Secure Electrical Conductor Connection

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Solution Overview

Problem

Existing electrical spring clamps face challenges in achieving sufficient clamping pressure for secure electrical contact between conductors without requiring additional tools, while also ensuring easy assembly and space efficiency.

Innovation Solution

A W-shaped spring clamp with a current-carrying element and spring receptacle, featuring obliquely arranged spring legs and safety edges, which generates independent spring forces for clamping and self-locking, allowing for easy insertion and secure holding of electrical conductors without the need for adjustment tools post-assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a higher spring force is used to increase clamping pressure, then the electrical contact properties are improved, but additional tools are required to open the spring for inserting the conductor

Engineering Contradiction:
Improveclamping pressureVSAvoidease of assembly
Core Design Contradiction:
ForceVSEase of operation

Solution Approach 1:

The spring is segmented into two independent legs that can be opened separately. This allows one leg to be opened with a simple tool to insert the conductor, while the other leg maintains clamping pressure, resolving the contradiction between high clamping force and ease of assembly

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The spring design allows the inserted conductor itself to act as a tool to open the spring leg during insertion. The conductor pushes against the spring leg to open it, then the spring automatically closes around the conductor, providing self-service functionality without requiring additional tools for the clamping action

Inventive Principle:
Principle #25Self-service

2Ease of operation

If the spring is designed to allow tool-free assembly with lower spring force, then the ease of operation is improved, but the clamping pressure is insufficient for secure electrical contact

Engineering Contradiction:
Improveease of assemblyVSAvoidclamping pressure
Core Design Contradiction:
Ease of operationVSForce

Solution Approach 1:

By dividing the spring into two independent legs, the system can have one leg designed for easy opening (low force requirement) and the other leg designed to maintain high clamping pressure, simultaneously achieving both ease of operation and sufficient clamping force

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The spring legs are designed with different functional characteristics - one leg is optimized for opening motion during insertion, while the other leg is optimized for maintaining clamping pressure. This dynamic differentiation allows the system to switch between ease of operation and high clamping force as needed

Inventive Principle:
Principle #15Dynamics

3Device complexity

If the spring legs are arranged vertically, then the structure is simple, but the conductor cannot be securely held against pulling out

Engineering Contradiction:
Improvestructural simplicityVSAvoidsecure holding
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The spring legs are arranged asymmetrically at oblique angles rather than vertically. This asymmetric arrangement creates a mechanical interlock that prevents the conductor from being pulled out, while maintaining relative structural simplicity. The oblique angles provide both insertion ease and retention security

Inventive Principle:
Principle #4Asymmetry

4Reliability

If the spring is designed with high spring force to prevent accidental loosening, then the reliability is improved, but the space required for the spring increases

Engineering Contradiction:
Improveprevention of accidental looseningVSAvoidspace requirement
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

Segmenting the spring into two legs allows compact arrangement where both legs share the same space envelope. The independent legs can be positioned to provide high clamping pressure and anti-loosening features without requiring proportionally more space, as the segments utilize space efficiently

Inventive Principle:
Principle #1Segmentation

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 provides a secure and reliable electrical connection with easy assembly and independent detachment of conductors, maintaining clamping pressure without additional tools, while preventing accidental loosening and allowing for various conductor types with adaptable spring force configurations.

Implementation Method 1

an essentially W-shaped spring... the spring force presses the conductor against the contact surface

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 2

the spring runs in a serpentine manner around the abutments. Thus, with the outer legs—essentially independently of one another—spring forces can be generated on both sides of the spring for clamping two electrical conductors

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 3

The spring ends are designed as a safety edge... The self-locking function is based on the principle of self-locking, in that the angular spring ends dig into the surface of the clamped conductor

Methodology Applied
Scientific EffectSelf-locking: Ratchet

Data Source

PatentEP2439816B1Electric plug connector
Publication Date: 2017.08.23 WOERTZ
  • EP2439816B1 patent drawingFigure 1~2
  • EP2439816B1 patent drawingFigure 3~4
  • EP2439816B1 patent drawingFigure 5

AI summary

The terminal (1) has a spring retainer with first, second and third counter bearings (6a-6c), where the second bearing is engaged with a loop (13), and the first and third bearings are engaged with a collar (12). A spring (5) is arranged between side walls (7). Arms (8) of the spring are arranged to the side walls. Spring ends (9) are formed as a train-protection edge such that an electrical conductor is inserted between the spring ends and the side walls. The conductor is pressed to a contact surface by spring force. A clamp housing (3) is made from an electrically insulating material.