Spring Tensioner for Stringed Instrument Tuning Stability

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Solution Overview

Problem

Stringed musical instruments often go out of tune due to variations in string tension over time, which can be caused by factors such as string elongation, contraction, and environmental changes, making tuning a laborious and inconvenient process.

Innovation Solution

A string mounting system that uses a spring assembly to maintain string tension within a desired range, incorporating a mechanical interface that adjusts force modulation to ensure the string remains in tune despite longitudinal movements, allowing for automatic adjustment and easy retuning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a spring assembly is used to maintain string tension, then the string remains in tune longer and tuning frequency is reduced, but the device complexity increases

Engineering Contradiction:
Improvetune stabilityVSAvoidmounting system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The spring assembly automatically adjusts string tension to compensate for elongation and environmental changes without requiring manual intervention. The system self-regulates tension within a desired range, making the instrument maintain its tune autonomously over time.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The mounting system transitions from a static fixed-tension design to a dynamic system where the spring continuously adapts tension based on string movement and environmental conditions, allowing the string to remain in tune despite external variations.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the string mounting system allows longitudinal movement to compensate for elongation, then tune stability is improved, but the mechanical complexity increases

Engineering Contradiction:
Improvepitch stabilityVSAvoidmechanical interface complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The mechanical interface acts as an intermediary between the string and the spring assembly, translating longitudinal string movement into controlled tension adjustments. This mediator component enables the spring to effectively regulate tension while accommodating string elongation.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If a spring assembly with mechanical advantage is used, then tension control precision is improved, but the device complexity and adjustment difficulty increase

Engineering Contradiction:
Improvetension control precisionVSAvoidtuning ease
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The spring assembly is designed to maintain tension within a desired range rather than fixing it at a single precise value. This partial action approach allows for acceptable tension variation that keeps the string in tune without requiring extremely precise mechanical control.

Inventive Principle:
Principle #16Partial or excessive action

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 system effectively maintains string tension close to perfect tune levels, reducing the need for frequent tuning and minimizing audible pitch changes, even with string elongation or contraction, thus simplifying the tuning process and maintaining instrument pitch stability.

Implementation Method 1

a spring assembly configured to apply a tension to the second end of the string so as to hold the string at a perfect tune tension

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP1999742B1Stringed musical instrument using spring tensioner
Publication Date: 2021.02.24 LYLES COSMOS
  • EP1999742B1 patent drawingFigure 1
  • EP1999742B1 patent drawingFigure 2
  • EP1999742B1 patent drawingFigure 3

AI summary

A stringed musical instrument employs springs to apply tension to corresponding musical strings. Each spring is chosen and configured for its ability to impart a string tension generally matched to the appropriate tension of the string at perfect tune. Preferably, the spring is selected and arranged so that the tension in the string maintains at or near perfect tune even as the string elongates or contracts over time. In one embodiment, once a string is placed in appropriate tune, a mechanical visual indicator is set. As such, if tune of the string changes due to string elongation or contraction, the change is reflected by misalignment of the mechanical visual indicator even if the change cannot be aurally detected. Perfect tune can be reestablished by realigning the indicator. In another embodiment, a force modulating member is interposed between a spring and its corresponding musical string. The force modulating member is adapted so that the tension actually applied to the string by the spring is not linearly related to the force exerted by the spring as the spring changes in length.