Multidirectional Knob Backlash Prevention via Segmented Bezel
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Solution Overview
Problem
Existing multidirectional operating devices experience backlash issues with the operational knob at the neutral position, preventing smooth rotation and inclination operations.
Innovation Solution
A multidirectional operating device design featuring an operational knob with a cylindrical portion and radial ribs, paired with a bezel portion containing limiting and permitting portions, which limits inclination at the neutral position and allows inclination by avoiding contact with the ribs when rotated, preventing backlash.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If engagement projection portions are arranged at spherical portion to limit inclination motion at neutral position, then backlash in specific direction is prevented, but backlash occurs in other directions
Solution Approach 1:
The bezel portion is segmented into multiple limiting portions (first, second, third, fourth) arranged at different angular positions, each corresponding to different operational directions. This segmentation allows backlash prevention in multiple directions simultaneously while maintaining smooth operation in permitted directions
Solution Approach 2:
Different regions of the bezel portion have different functional qualities: limiting portions create contact constraints at specific locations to prevent backlash, while permitting portions provide clearance for smooth inclined operation. This local differentiation resolves the contradiction between preventing backlash and maintaining operational smoothness
2Reliability
If limiting portions are added to prevent backlash in all directions, then operational stability is improved, but device complexity increases
Solution Approach 1:
The bezel portion serves multiple functions simultaneously: it provides structural support, defines operational limits, prevents backlash in multiple directions, and guides the operational knob. The limiting portions are integrated into the bezel structure rather than being separate components, reducing overall device complexity while achieving comprehensive backlash prevention
Data Source
Figure 1
Figure 2A~2C
Figure 3A~3B
AI summary
A multidirectional operating device 1 includes an operational knob 8 including a knob body 80 and plural ribs 84, and a bezel portion 7 disposed around a rotational axis of the operational knob. The bezel portion 8 includes plural limiting portions 760 formed standing from a top surface side so as to limit the inclination operation of the operational knob 8 by being opposite to a contact surface 842 of the ribs 84 when the operational knob 8 is located at a neutral position, and plural permitting portions 761 arranged between the limiting portions 760 so as to permit the inclination operation of the operational knob 8 while avoiding a contact with the contact surface 842 of the ribs 84 when the operational knob 8 is located at an operational position that allows the inclination operation by being rotated from the neutral position to a right or left position.