Knob Assembly with Coupling Joint to Absorb Cooktop Alignment Errors
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Solution Overview
Problem
Existing cooking appliance knobs face issues with misalignment due to assembly tolerance, leading to operational failures and aesthetic defects, and lack a reliable mechanism for fine adjustment of gas flow rate without separate components, compromising safety and user convenience.
Innovation Solution
A knob assembly with a joint that absorbs positional errors between the knob and valve shafts, featuring a Hall sensor and magnet for precise rotation measurement, and a knob ring for independent operation and display of power and timer settings, ensuring accurate alignment and operation while preventing gas leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a knob is directly connected to a valve shaft, then the structure is simple, but assembly tolerance causes misalignment and operational failure
Solution Approach 1:
The knob assembly is divided into separate components: a knob body, a valve shaft, and a coupling mechanism. The coupling mechanism includes a coupling body with multiple coupling arms that can independently adjust to accommodate misalignment between the knob and valve shaft, while maintaining reliable rotational transmission.
Solution Approach 2:
A coupling body acts as an intermediary between the knob and valve shaft. This coupling mechanism includes coupling arms that can flexibly adjust to absorb assembly tolerance and misalignment, ensuring reliable operation without direct rigid connection.
2Ease of operation
If a knob allows rotation without pushing, then operation is easy, but it cannot restrict rotation when not pushed
Solution Approach 1:
The coupling mechanism transitions between different dynamic states: a locked state where rotation is restricted when the knob is not pushed, and an unlocked state where rotation is freely transmitted when pushed. This dynamic behavior ensures both safety and ease of operation.
Solution Approach 2:
The coupling mechanism changes its mechanical parameters (rigidity vs. flexibility) based on operational state. When pushed, the coupling arms become flexible to allow rotation; when not pushed, they become rigid to restrict rotation and prevent accidental operation.
3Device complexity
If gas flow rate is adjusted by valve position, then control is simple, but fine adjustment without separate components is difficult
Solution Approach 1:
The coupling mechanism serves multiple functions: it transmits rotation from the knob to the valve shaft, compensates for misalignment, and enables fine adjustment of gas flow rate. This multi-functionality eliminates the need for separate adjustment components while maintaining precision.
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 solution stabilizes knob operation, enhances appearance quality, and improves user convenience by allowing precise control of gas flow without additional components, reducing the risk of accidents and operational defects.
Implementation Method 1
a Hall sensor and magnet for precise rotation measurement
Data Source
AI summary
A knob assembly includes a front panel, a knob located at a front side of the front panel and configured to rotate based on operation by a user, a knob shaft that is coupled to the knob and that extends through the front panel, a supporting pipe that receives the knob shaft and that supports the knob shaft, the supporting pipe being configured to maintain a position relative to the front panel, a valve configured to control supply of gas to the appliance, a valve shaft connected to the valve and configured to control the valve to adjust a flow rate of gas based on rotation of the valve shaft, and a joint that couples the knob shaft to the valve shaft and that is configured to transfer at least one of a rotational motion or a linear motion of the knob shaft to the valve shaft.