Rotary Knob Structure with Warped Annular Sheet
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Solution Overview
Problem
Existing rotary knob structures face challenges in maintaining consistent rotational resistance due to variations in dimensions, leading to increased backlash and wobble, as the annular spacer's tight interposition makes it difficult to provide a suitable magnitude of resistance.
Innovation Solution
The implementation of an annular sheet interposed between the device body and the rotary knob, with a body-side protrusion or sliding portion to warp the sheet, providing a biasing force that reduces backlash and allows for a consistent rotational resistance, absorbing dimensional variations through warpage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the annular spacer is tightly interposed in the clearance between the device body and the rotary knob, then rotational resistance is provided to the rotary knob, but the magnitude of rotational resistance changes when the clearance size changes due to dimensional variation
Solution Approach 1:
The patent changes the physical state of the annular spacer from a rigid component to an elastic component that can deform. By making the spacer elastic, it can adapt its shape and size to accommodate dimensional variations in the clearance while maintaining consistent rotational resistance through elastic deformation rather than rigid contact.
Solution Approach 2:
The patent introduces dynamic adaptability by allowing the annular spacer to elastically deform in response to clearance variations. This dynamic adjustment enables the spacer to maintain optimal contact and rotational resistance despite changes in dimensional parameters, transforming a static rigid structure into a dynamic adaptive system.
2Reliability
If the annular spacer is tightly interposed to provide rotational resistance, then backlash is reduced, but it becomes difficult to provide a suitable magnitude of rotational resistance when dimensions vary
Solution Approach 1:
By changing the material property of the annular spacer to elastic material, the system can maintain suitable rotational resistance magnitude despite dimensional variations. The elastic properties allow the spacer to deform and adapt, ensuring consistent operational characteristics while reducing backlash through maintained contact pressure.
3Reliability
If the clearance size changes due to dimensional variation of the rotary knob, then the magnitude of rotational resistance changes, but tight interposition is needed to reduce backlash
Solution Approach 1:
The patent resolves the sensitivity to manufacturing precision by changing the spacer from rigid to elastic. This parameter change allows the system to absorb dimensional variations through elastic deformation, making the rotational resistance independent of precise clearance dimensions while maintaining backlash reduction through continuous elastic contact.
Solution Approach 2:
The elastic annular spacer acts as a cushioning element that anticipates and absorbs dimensional variations before they affect rotational resistance. The elastic deformation provides a buffer against manufacturing tolerances, preventing backlash while compensating for size variations in advance.
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
This configuration ensures a consistent rotational resistance while minimizing backlash and wobble, effectively addressing the issue of dimensional variations in the rotary knob, ensuring reliable operation.
Implementation Method 1
a body-side protrusion provided at the device body to contact the annular sheet on the outside of the fixed portion in the radial direction of the annular sheet to warp the annular sheet toward the rotary knob
Implementation Method 2
the rotary knob contacts the annular sheet on the outside of the body-side protrusion in the radial direction of the annular sheet such that warpage of the annular sheet biases the rotary knob in the direction away from the device body, and is configured to be, in the biased state, slidable on the annular sheet such that the rotational resistance is provided to the rotary knob
Data Source
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AI summary
Provided is a rotary knob rotational structure being less susceptible to the influence of variation in the dimensions of a rotary knob and reducing backlash of the rotary knob while providing a suitable magnitude of rotational resistance to the rotary knob. The rotary knob rotational structure includes an annular sheet 22 interposed between a device body and the rotary knob 14, an attachment member 24 configured to attach a fixed portion 22a of the annular sheet 22 to the device body with the fixed portion 22a being interposed between the attachment member 24 and the device body, and a body-side protrusion 26 contacting the annular sheet 22 on the outside of the fixed portion 22a in the radial direction of the annular sheet 22 to warp the annular sheet 22 toward the rotary knob 14. The rotary knob 14 contacts the annular sheet 22 on the outside of the body-side protrusion 26 in the radial direction of the annular sheet 22 such that warpage of the annular sheet 22 biases the rotary knob 14 in the direction away from the device body, and is configured to be, in the biased state, slidable on the annular sheet 22 such that the rotational resistance is provided to the rotary knob 14.