Electric Toothbrush Neck Assembly Radial Motion Friction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electric toothbrush brush heads have a shorter useful life than the handle and require a mechanism that allows for easy attachment and detachment while maintaining reliable force and motion transfer, which existing designs often fail to achieve effectively.
Innovation Solution
A toothbrush neck assembly with a connecting arrangement that enables both radial and axial motion, utilizing a slide member and guide sleeve member to establish frictional contact between the drive shaft and the brush head, ensuring reliable force and motion transfer through a conical tapered surface alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the brush head is designed with a tight fit to provide reliable force transfer, then force transfer reliability is improved, but ease of attachment and detachment deteriorates
Solution Approach 1:
The connection mechanism transitions from a static tight fit to a dynamic system where the brush head moves radially inward during attachment to engage friction surfaces, then maintains optimal friction-based force transfer during operation. The radial motion capability allows the system to adapt between easy attachment and reliable force transfer states.
Solution Approach 2:
The system changes the friction parameter dynamically - during attachment, radial motion increases normal force to establish friction contact, and during operation, the friction coefficient and normal force are optimized to maintain reliable force transfer while allowing easy detachment when needed.
2Ease of operation
If the brush head is designed for easy removal and insertion, then ease of operation is improved, but force transfer reliability deteriorates
Solution Approach 1:
The connection mechanism uses radial motion capability to transition between attachment states. The ability to move radially allows the brush head to be easily inserted and removed while maintaining optimal friction contact during operation, resolving the contradiction between ease of operation and force transfer reliability.
Solution Approach 2:
The connection mechanism is segmented into multiple degrees of freedom - radial motion for attachment/detachment and axial motion for force transfer. This segmentation allows independent optimization of ease of operation (radial direction) and force transfer reliability (axial direction).
3Device complexity
If a single configuration is used for the brush head, then device complexity is reduced, but motion transfer efficiency deteriorates
Solution Approach 1:
Instead of using multiple static configurations, the system employs a single dynamic configuration capable of radial motion. This radial motion capability provides the same functional benefits as multiple configurations would offer, maintaining motion transfer efficiency while reducing overall device complexity.
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 solution allows for easy insertion and removal of the brush head with minimal effort while maintaining effective force and motion transfer, reducing motion loss due to high operating frequency and vibrations.
Implementation Method 1
The frictional contact enables a reliable transfer of at least one of force and motion from the drive shaft to the neck member
Data Source
Figure 1
Figure 2A~2C
Figure 3A~3C
AI summary
An attachment 10 mountable to an electric toothbrush handle 62 having a drive shaft 60 comprises a neck member 16 having an elongated body 40 with a principal axis 42 and a cavity 44; a slide member 12 with an engagement surface 22; a guide sleeve member 14 having a cavity 84, a first outer surface 88 with an engagement opening 90, and a transition surface 92; and a collar member 18. The guide sleeve member,with slide member moveably inserted within the engagement opening, is moveably inserted within the neck member cavity. Insertion of the drive shaft into cavities of the collar member and guide sleeve member from (a) a first radial position along an axis offset and parallel to the principal axis to (b) a second radial position in-line with the principal axis, via the transition surface, results in the drive shaft being held in frictional contact with the engagement surface of the slide member to enable reliable transfer of force/motion from the drive shaft to the neck member.