Racket String Angled Grommets Vibration Damping

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Solution Overview

Problem

Ball game rackets typically produce undesirable sounds due to their optimized shape and stringing materials, which are difficult to improve without compromising playability.

Innovation Solution

The racket design features strings guided through openings with specific angles, causing deflection and increased friction, which dampens vibrations and modifies the sound profile without affecting playability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the shape and material of the racket frame and stringing are optimized for playability, then playing performance is improved, but sound quality deteriorates (producing unpleasant high frequencies and excessive reverberation)

Engineering Contradiction:
Improveplaying performanceVSAvoidsound quality
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces an intermediary element (the angled opening or grommet) between the string and the frame. This intermediary redirects the string at a specific angle (5-15 degrees) relative to the frame surface, creating controlled friction that dampens unwanted vibrations and reverberation while preserving the playing characteristics of the optimized stringing

Inventive Principle:
Principle #24Intermediary (Mediator)

2Strength

If stringing hardness and material are increased for better playability, then ball control is improved, but sound becomes more unpleasant (higher frequencies and longer reverberation)

Engineering Contradiction:
Improveball controlVSAvoidsound frequency and duration
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The patent changes a critical parameter - the angle between the string direction and the frame surface (5-15 degrees). This angular parameter modification alters the friction characteristics and vibration damping without requiring changes to the stringing hardness or material, thus maintaining ball control while improving sound quality

Inventive Principle:
Principle #35Parameter changes

3Productivity

If the racket frame is designed for optimal playability, then performance is maximized, but sound reverberation increases causing unpleasant auditory experience

Engineering Contradiction:
ImproveperformanceVSAvoidsound reverberation duration
Core Design Contradiction:
ProductivityVSDuration of action of moving object

Solution Approach 1:

The patent applies local quality modification by creating a specific geometric feature (angled opening/grommet) at the string-frame interface. This localized structural change affects only the vibration damping characteristics at the contact point, reducing reverberation duration without altering the overall frame design or playing performance

Inventive Principle:
Principle #3Local quality

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 design enhances the sound experience by controlling string vibration and reverberation, providing a more pleasant sound without compromising the racket's performance.

Implementation Method 1

the sliding frictional force of the strings on the respective opening wall section can be controlled in such a way that the string vibration is damped relatively quickly

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

the string vibration is damped relatively quickly and long reverberation is avoided

Methodology Applied
Scientific EffectVibration damping: Damping

Data Source

PatentEP2823866B1Racket with improved sound
Publication Date: 2017.09.13 HEAD TECHNOLOGY GMBH
  • EP2823866B1 patent drawingFigure 1a~4d
  • EP2823866B1 patent drawingFigure 5~6b

AI summary

The present invention relates to a ball game racket with a frame forming a head section and a handle section, wherein the head section accommodates a stringing with strings that defines a stringing plane, wherein the strings of the stringing are guided through several openings in the head section, wherein at least three strings are guided through three of the openings such that the longitudinal axis of the opening runs in a first direction and the string guided through the opening runs within the stringing in a second direction, wherein the first and second directions enclose an angle with an absolute value between 0.5° and 15° and wherein the angle of these three strings differs in its absolute value by a maximum of 3°.