Connecting structure connecting an electric cleaning device handle and a head assembly

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Solution Overview

Problem

Existing detachable connecting structures for vibrating electric cleaning appliances, such as electric toothbrushes, pose safety hazards and reduce the service life due to improper fit and frequent plugging/unplugging, leading to potential injury and structural damage.

Innovation Solution

A detachable connecting structure featuring a buckle combination part with a buckle cantilever and buckle protrusion, a metal vibration shaft, and precise circular arc surfaces, ensuring secure attachment and easy replacement without increasing the appliance's volume.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the protrusion and groove fit tightly to prevent head assembly from slipping off, then the reliability of connection is improved, but the user needs to pull and insert forcefully when replacing the head assembly which may cause injury

Engineering Contradiction:
Improveconnection reliabilityVSAvoidease of replacement
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The connection structure is divided into multiple functional elements: a buckle combination part with buckle cantilever and buckle protrusion for secure locking, and a separate vibration shaft with circular arc surfaces for transmission. This segmentation allows the buckle mechanism to provide strong retention while the circular arc surfaces enable smooth insertion and removal through rotational motion

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The connection mechanism transitions from a static tight fit to a dynamic buckling system. The buckle cantilever can deflect and the buckle protrusion can rotate along the circular arc surfaces, allowing the connection to adapt between secure locked state during use and easy release state during replacement

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If the protrusion and groove fit not tightly enough to allow easy replacement, then the ease of operation is improved, but the head assembly is easy to slip off or even fly out

Engineering Contradiction:
Improveease of replacementVSAvoidconnection reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The vibration shaft is nested within the brush handle housing, with the buckle combination part positioned inside the hollow portion of the brush handle housing. The buckle protrusion fits within the buckle cavity, creating a nested structure that secures the head assembly while allowing easy removal through rotational motion along the circular arc surfaces

Inventive Principle:
Principle #7Nested doll (Nesting)

3Adaptability or versatility

If frequent plugging and unplugging occurs to enable head assembly replacement, then the adaptability is improved, but the connecting structure is easily damaged which reduces the service life

Engineering Contradiction:
Improvehead assembly replaceabilityVSAvoidservice life of connecting structure
Core Design Contradiction:
Adaptability or versatilityVSDuration of action of stationary object

Solution Approach 1:

The traditional direct protrusion-groove mechanical connection is replaced with a buckling mechanism combined with circular arc surfaces. The buckle cantilever uses elastic deformation to provide locking force, and the circular arc surfaces guide smooth rotational motion, reducing mechanical stress and wear on the connecting structure during frequent replacements

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

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 structure allows for safe and reliable detachment and attachment of the head assembly, extending the appliance's lifespan and reducing the risk of injury, while maintaining efficient operation and cost-effectiveness.

Implementation Method 1

a vibration motor (19)

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 2

The buckle cantilever (24) and the buckle protrusion (29) are made to contact each other to generate a friction force (Fp)

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3936083B1Connecting structure connecting an electric cleaning device handle and a head assembly
Publication Date: 2025.07.09 SHANGHAI SHIFT ELECTRIC CO LTD
  • EP3936083B1 patent drawingFigure 1
  • EP3936083B1 patent drawingFigure 2
  • EP3936083B1 patent drawingFigure 3

AI summary

Provided is a connecting structure for connecting a head assembly and a handle portion of avibration cleaning appliance, the handle portion includes a handle housing with a hollow portion and a vibration shaft, the head assembly includes a brush handle housing with a handle interface, a blind hole is provided in the middle of the interface, the rear end of the shaft is tightly inserted into the hole; a buckle cavity is provided on the interface, the front end surface of the cavity is a buckle locking surface of the interface; a buckle combination part including a cantilever and a protrusion is provided in the housing along its rear end, the cantilever is formed in and separated from the housing, the rear end of the cantilever is provided with the protrusion, a locking surface of the combination part is provided on the protrusion accommodated by the cavity of the interface.