Knurled Contact Assembly for Weld-Free Busbar Connections

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Solution Overview

Problem

Existing busbars with integrated contact sections face design restrictions due to manufacturing challenges, limiting geometry and material choices, especially in battery applications, and welding introduces contamination and weldability issues.

Innovation Solution

A contact assembly with a fastening element featuring a knurled section that exerts a contact force to press a contact element against a busbar, allowing non-welding connection of thin sheet metal pieces, enhancing contact area and reducing resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If contact sections are welded to the busbar, then electrical connection is achieved, but material choices are restricted due to weldability requirements and contamination occurs

Engineering Contradiction:
Improveelectrical connectionVSAvoidmaterial choice
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent replaces the welding process (thermal/chemical joining) with a mechanical fastening system consisting of a fastening element that mechanically secures the contact element to the busbar. This substitution eliminates weldability restrictions and allows use of materials like aluminum and copper alloys that are difficult or unsuitable for welding, while maintaining reliable electrical connection through the mechanical clamp connection.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Ease of manufacture

If busbar is manufactured integrally with contact section, then production is simplified, but geometry and profile are limited

Engineering Contradiction:
Improveproduction processVSAvoidbusbar geometry
Core Design Contradiction:
Ease of manufactureVSShape

Solution Approach 1:

The patent divides the busbar system into separate functional components: the busbar body and the contact element. The contact element is a separate component that can be inserted into and mechanically fastened to the busbar, allowing the busbar to be manufactured with complex profiles and geometries without the constraints of integral manufacturing processes like forging or extrusion.

Inventive Principle:
Principle #1Segmentation

3Area of stationary object

If knurled section length is increased to press contact element flatly, then contact area increases, but fastening element complexity increases

Engineering Contradiction:
Improvecontact areaVSAvoidfastening element structure
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent applies knurling (a surface texturing process) to the fastening element's contact surface, creating a patterned texture that increases friction and pressing force distribution. This surface modification allows the fastening element to effectively press the contact element flatly against the busbar with adequate contact area without requiring excessive increase in the axial length of the fastening element.

Inventive Principle:
Principle #32Color changes

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

Facilitates flexible geometry and material choice, reduces energy consumption, and avoids contamination by providing a reliable, low-resistance electrical connection without welding, suitable for thin busbars and layered sheet metal conductors.

Implementation Method 1

the contact element is configured to be affixed in a frictionally engaged manner to the busbar at least at a first friction surface in the receiving opening

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

the knurled section is configured such that the knurled section in the assembled state exerts a contact force upon the contact element which presses the first friction surface of the contact element flatly against the inner side of the receiving opening of the busbar

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP4645603A1Electrically conductive contact assembly, module connector, connection assembly and method for mechanical fastening
Publication Date: 2025.11.05 TE CONNECTIVITY SOLUTIONS GMBH
  • EP4645603A1 patent drawingFigure 1~2
  • EP4645603A1 patent drawingFigure 3
  • EP4645603A1 patent drawingFigure 4

AI summary

The present invention relates to an electrically conductive contact assembly (100, 100', 100"), wherein the contact assembly (100, 100', 100") comprises a contact element (106), a busbar (102) and a fastening element (110, 110', 110") for mechanically fastening the contact element (106) to the busbar (102). The contact element (106) is configured to be affixed to the busbar (102) in a frictionally engaged manner at least on a first friction surface (120) in the receiving opening (104), and the fastening element (110, 110', 110") comprises a knurled section (138) which is longer in the axial direction (A) or of the same length as the receiving opening (104) of the busbar (102). The knurled section (138) is configured such that the knurled section (138) in the assembled state of the contact assembly (100, 100', 100") exerts a contact force (FK) upon the contact element (106) which presses the first friction surface (120) of the contact element (106) flatly against the inner side of the receiving opening (104) of the busbar (102). Furthermore, the present invention relates to a method for mechanically fastening a contact element (106) to a busbar (102).