Knob assembly for cook top
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Solution Overview
Problem
The existing knob assemblies for cooking appliances are complex and prone to misalignment, leading to operational failures and aesthetic issues due to assembly tolerance errors, which affect the reliability and appearance quality.
Innovation Solution
A knob assembly with a joint between the knob and valve assembly to absorb positional errors, featuring a Hall sensor and magnet system for precise rotation sensing and display of firepower levels, and a locking mechanism to prevent accidental rotation, ensuring accurate alignment and operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a knob and knob ring are arranged coaxially to rotate independently for controlling different functions, then the product aesthetics are enhanced and multiple functions are controlled, but the structure becomes complicated and assembling becomes difficult
Solution Approach 1:
The patent combines the knob and knob ring into a single integrated assembly where the knob ring is fixed to the knob body. This merging eliminates the need for separate mounting structures and simplifies the overall assembly while maintaining the ability to control multiple functions through the integrated design.
Solution Approach 2:
The integrated knob assembly serves multiple functions: the inner knob controls firepower intensity while the outer ring controls timer functions. This multi-functional design is achieved within a single structural unit, avoiding the complexity of completely separate components while maintaining versatility.
2Device complexity
If the knob is directly connected to the valve assembly without a joint, then the structure is simple, but assembly tolerance errors cause misalignment and operational failures
Solution Approach 1:
The patent introduces a joint as an intermediary component between the knob and valve assembly. This joint absorbs assembly tolerance errors and misalignments, ensuring reliable operation while maintaining overall structural simplicity. The joint acts as a buffer that compensates for manufacturing variations without adding significant complexity.
3Reliability
If the knob is pushed and rotated to control gas valve opening, then safety is improved by preventing accidental rotation, but the operation requires two actions which may reduce ease of use
Solution Approach 1:
The patent implements a dynamic locking mechanism where the knob's rotational capability is conditioned on the pushing action. The locking piece engages with the guide surface to prevent rotation unless the knob is first pushed, at which point the locking piece disengages to allow rotation. This dynamic behavior provides safety while maintaining operational convenience.
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, enhances appearance quality, and provides accurate sensing and control, reducing the risk of gas leakage and improving user safety by preventing unintended valve opening.
Implementation Method 1
a knob sensor configured to detect a rotational position of the valve shaft. The knob sensor includes a sensor plate mounted to the valve, a sensor board that is configured to move relative to the valve shaft along a longitudinal direction of the valve shaft, a rotating plate that is spaced apart from the sensor board, that is fixed to the valve shaft, and that is configured to rotate with the valve shaft, a knob sensor magnet disposed at the rotating plate, and a sensor spring configured to apply elastic force to the sensor board toward the rotating plate. The sensor board includes a plurality of Hall sensors arranged around the valve shaft.
Data Source
AI summary
A knob assembly includes a front panel, a knob located at a front panel of an appliance and configured to rotate based on operation by a user, a valve shaft that is coupled to the knob and that extends through the front panel, a valve connected to the valve shaft and configured to control supply of gas to the appliance, and a knob sensor configured to detect a rotational position of the valve shaft. The valve shaft is configured to control the valve to adjust a flow rate of gas based on rotation of the valve shaft.