Electric Toothbrush Handle Frame for Precise Drive Assembly

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Solution Overview

Problem

Existing electric toothbrush designs face challenges in achieving a compact, easy-to-assemble design with efficient motion transmission to the brush head, while ensuring low manufacturing costs and minimizing the risk of injury.

Innovation Solution

The electric toothbrush handle features a fixed, one-piece frame unit that accommodates the drive unit and energy storage device, with defined relative positioning, and includes a compressible length compensation element to absorb tolerances, allowing for pre-assembly and precise alignment of components, and a charging coil for wireless energy transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a brush attachment is designed with a universal interface receptacle for at least two different interfaces of different toothbrush handles, then the adaptability and versatility of the brush attachment is improved, but the device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improveinterface compatibilityVSAvoidinterface receptacle structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The interface receptacle is designed as a universal receptacle that can accommodate at least two different interface types (e.g., circular and rectangular interfaces) through a single structure. This allows the brush attachment to be compatible with multiple toothbrush handle types without requiring separate receptacles for each interface variant, thereby improving adaptability while managing complexity through design integration.

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

2Adaptability or versatility

If the interface receptacle is designed to fit interfaces of different shapes and dimensions, then the versatility is improved, but the manufacturing precision requirements increase

Engineering Contradiction:
Improveinterface shape accommodationVSAvoidreceptacle dimensional tolerance
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The interface receptacle incorporates elastic clamping elements that can dynamically adjust their position and shape to accommodate different interface geometries. This dynamic adaptation allows the receptacle to maintain precise clamping force across various interface types without requiring extremely tight manufacturing tolerances on the receptacle itself, as the elastic elements compensate for dimensional variations.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If a clamping unit with elastically deflatable elements is used to receive the interface, then the ease of operation and assembly is improved, but the device complexity increases

Engineering Contradiction:
Improveassembly easeVSAvoidclamping unit structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The clamping unit utilizes elastic elements that automatically deflect and return to their original position through their own elastic properties, without requiring external actuation mechanisms. When the interface is inserted, the elastic clamping elements naturally deflect to accommodate it and then spring back to secure it, providing self-service clamping action that simplifies operation while avoiding complex motorized or manually-actuated clamping systems.

Inventive Principle:
Principle #25Self-service

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

This design enables a robust, efficient, and cost-effective assembly process with precise component alignment, reducing the risk of assembly errors and ensuring consistent motion transmission to the brush head, enhancing user comfort and cleaning performance.

Implementation Method 1

at least one elastic element (150), in particular a compression spring element, arranged between the clamping unit and the interface element (112) of the drive unit (100) in an assembled state, which is provided for clamping the interface element (112) of the drive unit (100) in a defined position both in an assembled state and in an unassembled state of the frame unit (130)

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4201376B1Electric toothbrush handpiece and electric toothbrush
Publication Date: 2026.05.13 TRISA HLDG AG
  • EP4201376B1 patent drawingFigure 1~2
  • EP4201376B1 patent drawingFigure 3~4
  • EP4201376B1 patent drawingFigure 5~8

AI summary

The invention relates to an electric toothbrush handle with at least one interface (24a; 24b) for coupling with a brush head (10a; 10b), in particular according to one of the preceding claims, with at least one housing (46a; 46b), with at least one drive unit (48a; 48b) received in the housing (46a; 46b) for driving the interface (24a; 24b) and with at least one energy storage device (50.1a, 50.2a; 50.1b) for supplying the drive unit (48a; 48b) with energy. It is proposed that the electric toothbrush handle has at least one fixed, in particular one-piece, frame unit (52a; 52b) arranged in the housing (46a; 46b), which at least partially accommodates the drive unit (48a; 48b) and the energy storage device (50.1a, 50.2a; 50.1b), wherein the frame unit (52a; 52b) has several receiving areas at least for the drive unit (48a; 48b) and the energy storage device (50.1a, 50.2a; 50.1b).1b) forms which, both in an assembled state and in an unassembled state of the frame unit (52a; 52b), are positioned in a defined relative to each other, wherein the frame unit (52a; 52b) extends axially over the entire drive unit (48a; 48b) and the entire energy storage unit (50.1a, 50.2a; 50.1b).