String Instrument Adjuster Lever Perpendicular Swing

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Solution Overview

Problem

Conventional string instrument adjusters either require excessive force for tuning due to short lever lengths or disrupt the balance of musical sounds with uneven string lengths, limiting their effectiveness in fine-tuning small pitches.

Innovation Solution

An adjuster with a frame, mounting screw, lever, anchoring portion, and swing transmitting member is mounted on the tailpiece, allowing the lever to swing freely and adjust string tension through a coaxial adjusting screw and nut system, enabling easy tuning without affecting musical sound balance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the lever is made long to reduce controlling force, then ease of operation is improved, but the string length becomes short affecting musical sound balance

Engineering Contradiction:
Improveease of tuningVSAvoidstring length
Core Design Contradiction:
Ease of operationVSLength of moving object

Solution Approach 1:

The lever is configured to swing in a direction substantially perpendicular to the stretching direction of the string, utilizing a different spatial dimension for the adjustment mechanism. This allows the lever to achieve sufficient mechanical advantage without extending forward and reducing the string length, thereby maintaining both ease of operation and proper string length for musical balance.

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

2Length of moving object

If the lever is made short to maintain string length, then musical sound balance is improved, but large controlling force is required making tuning difficult

Engineering Contradiction:
Improvestring lengthVSAvoidease of tuning
Core Design Contradiction:
Length of moving objectVSEase of operation

Solution Approach 1:

By changing the swing direction of the lever to be perpendicular to the string stretching direction, the invention achieves effective lever arm length without compromising string length. This dimensional change allows a short lever to provide sufficient mechanical advantage for easy tuning while maintaining proper string length for musical balance.

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

3Device complexity

If the adjusting screw passes through the anchor hole from the back side, then the structure is simple, but the lever swing range is limited

Engineering Contradiction:
Improvestructure simplicityVSAvoidlever swing range
Core Design Contradiction:
Device complexityVSLength of moving object

Solution Approach 1:

Instead of having the adjusting screw pass through the anchor hole from the back side, the invention inverts the arrangement by having the adjusting screw pass through from the front side of the tailpiece. This allows the lever to swing freely over the anchor hole without being constrained by the screw position, thereby increasing the lever swing range while maintaining structural simplicity.

Inventive Principle:
Principle #13The other way round (Inversion)

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

Facilitates easy and precise tuning of small pitches with reduced controlling force and minimal impact on musical sound balance, offering a larger tuning range and improved usability.

Implementation Method 1

an adjusting screw 40 which is screwed from the front side into the screw portion 35

Methodology Applied
Scientific EffectScrew mechanism: Screw

Implementation Method 2

a lever member 50 which is swingably supported by the frame 30 and is controlled by the adjusting screw 40

Methodology Applied
Scientific EffectLever mechanism: Lever

Implementation Method 3

the lever member 50 is swingable in a direction for stretching the string 8

Methodology Applied
Scientific EffectMechanical force: Mechanical Force

Data Source

PatentEP2600338B1Adjuster for string instruments
Publication Date: 2014.12.03 GOTOH GUT
  • EP2600338B1 patent drawingFigure 1~2
  • EP2600338B1 patent drawingFigure 3A~3B
  • EP2600338B1 patent drawingFigure 4A~4D

AI summary

An adjuster facilitates tuning of a string instrument and does not greatly affect musical sounds. The adjuster includes a frame 30, a second lever 52, an adjusting screw 40, and a first lever 51 (swing transmitting member, transmitting lever, lever portion). The frame 30 is made so as to be removably fixed to a front end portion of a tailpiece 6 with a fixing means 70 and has a screw portion (mounting portion) 35 at the front side of the tailpiece 6. The second lever 52 is made so as to be arranged by passing through an anchor hole 11 formed at the tailpiece 6. The second lever 52 is supported by the frame 30 so as to be swingable in a direction for stretching a string. The second lever 52 has a hook portion (anchoring portion) 56 which projects from a surface of the tailpiece 6 and removably anchors a back end of a string 8. The adjusting screw 40 is mounted by screwing it from the surface side of the tailpiece 6 into the screw portion 35 of the frame 30. The first lever 51 is provided to the frame 30 so as to be interposed between the adjusting screw 40 and the second lever 52. The first lever 51 swings the second lever 52 to a tightening side or a loosening side in the direction for stretching the string according to the screwed amount of the adjusting screw 40.