Knob assembly and cooking appliance including a knob assembly
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Solution Overview
Problem
Manufacturing tolerances and assembly deviations in cooking apparatus knobs lead to misalignment, external defects, and malfunctions due to twisted valve shafts, affecting the smooth operation and appearance of gas range controls.
Innovation Solution
A knob assembly design featuring a movable valve shaft, a knob ring that supports the knob shaft at multiple points, an actuating member with restoring springs, and a fixing frame to restrict rotation within a predetermined angle, ensuring precise alignment and smooth operation, along with a display for timer and heating power settings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed valve shaft is used in the knob assembly, then the structure is simple, but manufacturing tolerances and assembly deviations cause misalignment and malfunctions
Solution Approach 1:
The valve shaft is designed to be movable rather than fixed, allowing it to dynamically adjust its position to compensate for manufacturing tolerances and assembly deviations. The movable valve shaft can shift within the valve body to maintain proper alignment with the knob, ensuring reliable operation despite variations in component dimensions.
Solution Approach 2:
The patent changes the positional parameter of the valve shaft from fixed to variable. By allowing the valve shaft to move within a certain range, the system can adapt to different assembly conditions and maintain optimal alignment, thereby improving reliability without requiring extremely tight manufacturing tolerances.
2Shape
If the knob is rigidly fixed to the valve shaft, then the structure is simple, but assembly deviations spoil the external shape and cause misalignment
Solution Approach 1:
The patent introduces an intermediary structure between the knob and valve shaft that allows for positional adjustment. This intermediary mechanism absorbs assembly deviations and prevents them from being transmitted to the external knob alignment, maintaining the aesthetic appearance and proper positioning of the knob assembly.
3Ease of operation
If the actuating member is freely movable, then the operation is smooth, but the member may separate from the support frame
Solution Approach 1:
The patent applies different local qualities to the actuating member structure: the portion that contacts the support frame has retention features to prevent separation, while the rotating portion maintains smooth surfaces for easy operation. This localized differentiation of functional properties allows the member to both move smoothly and remain securely connected.
4Adaptability or versatility
If the knob assembly allows full rotation, then the operation flexibility is high, but the valve shaft may twist and malfunction
Solution Approach 1:
The valve shaft is designed with dynamic movement capability, allowing it to adjust its angular position within the valve body during knob rotation. This dynamic adjustment prevents twisting and maintains proper alignment with the valve components, enabling full rotation flexibility without compromising reliability.
Data Source
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AI summary
A knob assembly and a cooking apparatus including a knob assembly are provided. The knob assembly may reduce defects in assembly and operation of the knob assembly caused by a tolerance of a valve shaft. The knob assembly may include a valve in which a valve shaft may be movable, a knob connected to a knob shaft coupled with the valve shaft, a knob ring that surrounds a periphery of the knob and supports the knob shaft, a actuating member coupled with the knob ring, a support frame that supports an outer circumferential surface of the actuating member, and a fixing frame coupled with the support frame to prevent the actuating member from separating from the support frame.