Rotating Power Connector With Disc Contacts for Low-Friction Reliability

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Solution Overview

Problem

Existing connectors for electrical appliances generate significant friction and heat due to cylindrical contacts, leading to reliability issues and cable twisting when frequently rotated, especially in devices like hair dryers used by professionals.

Innovation Solution

A connector design featuring a rotating body with overlapping metal discs and insulating spacer, crimped electrical wires, and sliding pliers contacts, allowing free rotation while ensuring stable electrical contact through crimping and low friction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If cylindrical contacts are used in the connector, then reliable electrical connection is ensured, but significant friction and heat are generated during rotation

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidfriction and heat generation
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent divides the continuous cylindrical contact surface into discrete point contacts using a star-shaped geometry. The male connector has protrusions that contact specific points on the female connector's recesses, transforming the distributed friction of a cylindrical surface into localized point contacts that reduce overall friction and heat generation while maintaining electrical connectivity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs asymmetric star-shaped contact geometries where the male connector has protrusions with specific angular orientations that engage with corresponding recesses in the female connector. This asymmetric design creates preferred rotation paths and reduces binding friction compared to symmetric cylindrical contacts, allowing smoother rotation while maintaining reliable electrical contact at the asymmetric contact points.

Inventive Principle:
Principle #4Asymmetry

2Ease of operation

If cylindrical contacts allow 360° rotation, then cable freedom is achieved, but friction distributed over the entire surface affects long-term reliability

Engineering Contradiction:
Improvecable rotation freedomVSAvoidlong-term electrical connection reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

By segmenting the contact interface into discrete star-shaped protrusions and recesses, the patent enables rotation around a central axis while concentrating wear and friction to specific localized points rather than distributing it across the entire cylindrical surface. This segmentation allows the cable to rotate freely while the contact points maintain stable engagement, improving long-term reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The star-shaped contact geometry provides dynamic characteristics during rotation, where the contact points naturally guide the rotation motion through their geometric configuration. This dynamic interaction allows smooth rotation while maintaining consistent electrical contact, as the asymmetric star shape creates natural rotation paths that reduce binding and maintain reliability over time.

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 design provides stable electrical contact with reduced friction and heat generation, preventing cable kinking and maintaining reliable connections over time.

Implementation Method 1

The housings consist of two retention springs of a metallic nature and are essentially cylindrical in shape with a radius which allows the pin or tip and ring to be inserted and disengaged therefrom and have adequate elastic properties.

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4430711B1Connector for the electrical connection of an electrical appliance to the electrical network
Publication Date: 2025.10.15 KERZ SRL
  • EP4430711B1 patent drawingFigure 1~2
  • EP4430711B1 patent drawingFigure 3~4
  • EP4430711B1 patent drawingFigure 5~6

AI summary

Connector for the electrical connection of an electrical appliance to a supply power cable comprising a rotating body (2) associated with the power supply cable, and an annular element (3) surrounding the rotating body and which, when coupled, electrically connect through respective electrical contacts. The rotating body (2) and annular element (3), when assembled together, are capable of relative rotation around a longitudinal axis X of the rotating body. The rotating body (2) is elongated and comprises a first (D1) and a second (D2) electrical contact which both appear as discs, concentric and superimposed. The annular element (3) comprises a pair of jaws (31,32), which close on the rotating body and a third (P1) and a fourth (P2) electrical contact inside at least one of the two jaws, said third and fourth electrical contact appear as pliers which grip the respective disc (D1, D2), making a sliding electrical contact.