Cooktop Knob Assembly with Joint Mechanism to Absorb Alignment Errors
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Solution Overview
Problem
Existing cooking appliance knobs face misalignment issues due to assembly tolerance, leading to operational failures and aesthetic defects, and lack a reliable mechanism for fine adjustment of gas flow rate without separating components.
Innovation Solution
A knob assembly with a joint that absorbs positional errors between the knob and valve shafts, featuring a knob ring with a display device for setting and displaying timer and firepower levels, using a Hall sensor and magnet for precise rotation sensing, and a push-and-turn mechanism to prevent accidental rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a knob is directly connected to a valve shaft without a joint mechanism, then the structure is simpler, but assembly tolerance accumulates causing misalignment and operational failure
Solution Approach 1:
A joint mechanism is introduced as an intermediary component between the knob and valve shaft. This joint absorbs assembly tolerance and positional errors, preventing misalignment while maintaining rotational motion transmission. The joint acts as a buffer that compensates for manufacturing variations without requiring complex adjustment mechanisms.
2Manufacturing precision
If the knob structure is made more complex to absorb assembly tolerance, then alignment quality improves, but device complexity increases
Solution Approach 1:
The joint serves as a simple intermediary that absorbs positional errors between the knob and valve shaft. Rather than requiring precise manufacturing tolerances throughout the assembly, the joint provides a straightforward mechanical solution that compensates for tolerance accumulation while adding minimal structural complexity.
3Reliability
If a push-and-turn mechanism is implemented to prevent accidental rotation, then operational safety improves, but ease of operation decreases
Solution Approach 1:
The knob mechanism transitions from a static locked state to a dynamic operational state through a push action. When the user pushes the knob, it releases from its locked position and becomes rotatable, allowing intentional operation. This dynamic state change prevents accidental rotation while enabling easy intentional control.
4Adaptability or versatility
If multiple separate components are used for knob assembly, then adjustability improves, but ease of manufacture decreases
Solution Approach 1:
The knob assembly is segmented into distinct functional components: the knob body, the joint mechanism, and the valve shaft connection. This segmentation allows each component to be manufactured and adjusted independently, providing fine adjustment capability for aligning the knob with the front panel while maintaining relatively simple manufacturing processes for each individual part.
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 the knob operation, improves appearance quality, and enhances user convenience by allowing precise control over gas flow without additional components, reducing the risk of gas leakage and operational errors.
Implementation Method 1
using a Hall sensor and magnet for precise rotation sensing
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.