Toothbrush Hinge and Torsion Spring for Force-Limited Brushing
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Solution Overview
Problem
Existing toothbrushes may cause damage to teeth due to excessive brushing force applied by users, leading to stress beyond the cleaning requirements.
Innovation Solution
A toothbrush design featuring a brush head linkage connected to a toothbrush handle through a connecting mechanism with an elastic structural element, including a helix spring and torsion bars, allowing the brush head to oscillate relative to the handle, limiting excessive force transmission and providing feedback to the user through handle attitude changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If users apply more pressing and pushing forces to the toothbrush handle for better cleaning effect, then cleaning effectiveness is improved, but teeth are subjected to excessive stress causing damage
Solution Approach 1:
The toothbrush incorporates a hinge joint between the head and handle that allows the brush head to rotate dynamically in response to applied forces. This dynamic mechanism automatically adjusts the brushing angle and reduces force transmission when excessive pressure is applied, preventing tooth damage while maintaining cleaning effectiveness through controlled movement rather than rigid force transmission.
Solution Approach 2:
The hinge mechanism changes the mechanical parameters of force transmission by introducing rotational degrees of freedom. When users apply pressing and pushing forces, the hinge transforms linear force into rotational motion, altering the stress distribution and limiting the maximum stress transmitted to the teeth, thus resolving the contradiction between cleaning effectiveness and tooth protection.
2Object-affected harmful factors
If a hinge mechanism is added to modify flexibility and prevent excessive force transmission, then tooth protection is improved, but device complexity increases
Solution Approach 1:
The hinge mechanism is segmented into simple modular components including a hinge axis, connecting arms, and friction elements. This segmentation allows the complex function of force modulation to be achieved through simple, manufacturable parts that can be assembled from discrete elements, reducing overall device complexity while maintaining the protective function.
Solution Approach 2:
The hinge mechanism is designed to be self-regulating through friction and gravitational forces, automatically adjusting to user-applied pressure without requiring external control systems or complex actuators. The mechanism self-adjusts the brush head angle and force transmission based on the user's brushing pressure, eliminating the need for motors, sensors, or electronic controls, thus maintaining simplicity.
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 prevents tooth damage by limiting excessive brushing force and enhances user control over brushing strength, ensuring gentle cleaning while maintaining comfort and usability.
Implementation Method 1
when the force that needs to be transmitted to the brush head linkage through the connecting mechanism and that is not perpendicular to the direction parallel to the front-rear direction is just greater than an external force required for the elastic deformation of the return torsion spring, each of the return torsion springs is elastically deformed
Implementation Method 2
the return torsion spring comprises a helix spring in the form of a cylinder with an opening of the cylinder oriented in a direction parallel to an extension direction of the oscillating reference line
Implementation Method 3
the first connector is rotatably connected to the second connector, and the axis of rotation is an oscillating reference line perpendicular to a vertical direction
Data Source
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AI summary
A toothbrush comprises a brush head linkage (100), a connecting mechanism (200) and a toothbrush handle (300); the connecting mechanism (200) comprises a first connector (210), a second connector (220) and an elastic structural element (230) connected to the second connector (220); the first connector (100) is rotatably connected to the second connector (220), and the axis of rotation extends in a front-rear direction; and the elastic structural element (230) comprises at least one return torsion spring (231), the return torsion spring (231) comprises a helix spring (2311) in the form of a cylinder with an opening of the cylinder oriented in a direction parallel to an extension direction of an oscillating reference line, the helix spring is in stop fit with the second connector (220) in a direction perpendicular to the oscillating reference line, and the return torsion spring further comprises a first torsion bar (2311) and a second torsion bar (2312) respectively connected to a front end and a rear end of the helix spring (2311) . The toothbrush according to the present invention can protect teeth.