Drum Lug Structure with Planar Contact for Positional Stability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing drum lug structures face challenges in maintaining positional precision and stability, preventing rotational and horizontal movement, and facilitating easy installation and tone adjustment due to issues with engagement grooves, protrusions, and lug nut alignment.

Innovation Solution

The drum lug structure incorporates a cylindrical shaft-shape portion with two planar contact locations on the lug base, along with tapered mating portions to enhance stability and precision, allowing for precise positioning and easy installation, and varying lug materials (zinc, aluminum, magnesium) to adjust the drum tone by changing the total mass.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a V-shape engagement groove and angled protrusion are used to install the lug on the drum shell, then the lug can be installed, but rotational movement and inclination in the circumferential direction cannot be restrained

Engineering Contradiction:
Improvelug installationVSAvoidlug positional stability
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The invention transitions from a single-point engagement (V-groove and angled protrusion) to a two-dimensional planar contact interface. The shaft-shape portion is provided with two planar portions that contact two distinct locations on the lug base, creating a stable triangular support structure that prevents rotation and inclination while maintaining ease of installation.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Ease of manufacture

If a semicircular receiving groove is used for the lug nut, then the lug nut can be received, but single-point contact causes easy shifting in horizontal directions

Engineering Contradiction:
Improvelug nut receptionVSAvoidlug nut positional stability
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The invention replaces the curved semicircular groove with a flat planar surface for Lug nut contact. This planar portion provides a stable two-dimensional contact interface instead of single-point contact, preventing horizontal shifting while maintaining the simplicity of the receiving structure.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Ease of operation

If the engagement groove and protrusion are designed for easy installation, then installation is simplified, but the lug moves easily when the tightening bolt is loosened requiring manual holding

Engineering Contradiction:
Improvelug installationVSAvoidlug control during installation
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The shaft-shape portion with two planar portions contacting the lug base creates a self-stabilizing structure. When the tightening bolt is loosened, the lug automatically returns to its stable position on the planar contact surfaces without requiring manual holding or complex retention mechanisms, while still allowing easy installation.

Inventive Principle:
Principle #25Self-service

4Adaptability or versatility

If the total mass of lugs is changed to adjust drum tone, then tone adjustability is improved, but requiring multiple lug variants increases manufacturing complexity

Engineering Contradiction:
Improvedrum tone adjustabilityVSAvoidlug production
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The invention enables tone adjustment by changing the mass parameter of the lugs. Multiple lug variants with different masses (made from zinc, aluminum, or magnesium) can be prepared using the same shaft-shape portion design, allowing simple mass variation through material selection rather than structural redesign, thus maintaining ease of manufacture while achieving tone adjustability.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2079076B1Lug structure of drum
Publication Date: 2012.04.25 YAMAHA CORP
  • EP2079076B1 patent drawingFigure 1
  • EP2079076B1 patent drawingFigure 2A~3
  • EP2079076B1 patent drawingFigure 4A~4D

AI summary

The lug structure of a drum for installing a drum head on a drum shell according to the present invention, includes: a lug base which is installed on the drum shell; a lug which is held by the lug base, and which supports one end of a tightening bolt; and a lug movement restraining portion which is provided between the lug base and the lug, and includes a shaft-shape portion provided on the lug, and two planar portions provided on the lug base, and the two planar portions extend substantially parallel to the longitudinal axis of the shaft-shape portion and are contactable with the shaft-shape portion.