Eccentric Taper Adjustment Bolt Assembly for Drum Anti-Loosening
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Tension bolts on drums tend to loosen during performances, especially in genres like hard-rock or heavy-metal music, affecting the drum's pitch and sound quality, and existing solutions like washers are inadequate or cumbersome to use.
Innovation Solution
An anti-loosening adjustment bolt assembly featuring a screw shaft, a cylindrical pipe with a female screw, and a nut with an eccentric taper surface that generates prevailing torque when tightened, preventing the bolt from loosening by creating frictional resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If washers are used to prevent bolt loosening, then the structure is simple, but the anti-loosening effect is insufficient
Solution Approach 1:
The nut is designed with an asymmetric structure where the threaded hole axis is inclined relative to the central axis, creating an asymmetric contact pattern with the cylindrical pipe that generates prevailing torque to prevent loosening
Solution Approach 2:
A taper surface is introduced into the nut structure, creating a curved contact surface that generates mechanical advantage and prevailing torque when the nut is tightened against the cylindrical pipe
2Reliability
If stoppers are used to prevent bolt loosening, then the anti-loosening effect is sufficient, but the stoppers must be removed each time the drum is tuned which is troublesome
Solution Approach 1:
The nut automatically generates prevailing torque through its inclined threaded hole design, providing self-service anti-loosening protection without requiring external stoppers or manual intervention during tuning operations
Solution Approach 2:
The nut is designed to dynamically adjust its position and contact force with the cylindrical pipe based on the tightening force applied, automatically maintaining appropriate prevailing torque throughout the tuning range
3Reliability
If the nut is tightened with large tightening force to generate large anti-loosening effect, then the prevailing torque is sufficient, but the adjustment bolt becomes difficult to rotate for tuning
Solution Approach 1:
The inclined angle of the threaded hole and the taper surface angle are optimized to provide an optimal balance between prevailing torque generation and rotational ease, allowing sufficient anti-loosening effect while maintaining tunability
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 effectively prevents bolt loosening during performances, maintaining the drum's pitch and sound quality without requiring frequent adjustments, allowing for easy tuning and secure tightening.
Implementation Method 1
one end of the cylindrical pipe comes into strong pressure-contact with a circumferential portion of the eccentric taper surface of the nut such that the nut is slightly eccentric and/or inclined from the screw shaft within the range for fitting between the threaded hole of the nut and the screw shaft and a circumferential portion of the threaded hole of the nut is laterally pushed against the screw shaft such that the frictional resistance between the nut and screw shaft gives prevailing torque to the adjustment bolt
Data Source
AI summary
It is made possible to give prevailing torque to an adjustment bolt in a simple manner without troublesome adjustment work. An anti-loosening adjustment bolt assembly includes: a cylindrical pipe (6) adapted to be fitted on the screw shaft (2a) of the adjustment bolt (2); and a nut (7) having a threaded hole for allowing the screw shaft (2a) to be threadably mounted thereon; the bottom of the nut (7) includes a recess (7a) adapted to allow the upper end of the cylindrical pipe (6) to be fitted therein; the inner peripheral surface of the recess (7a) is a taper surface decreasing in diameter toward the interior; and the axis of the taper surface is slightly eccentric from the axis of the threaded hole such that, when the nut (7), threadably secured to the screw shaft (2a), is screwed toward the cylindrical pipe (6), a circumferential portion of the eccentric taper surface comes into pressure-contact with the upper end of the cylindrical pipe (6) and the axis (Q) of the threaded hole of the nut (7) is eccentric and/or inclined from the axis (O) of the screw shaft (2a) to generate prevailing torque depending on the amount of tightening of the nut (7) on the adjustment bolt (2).