Tennis Racket String Layout for Spin and Control Balance

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Solution Overview

Problem

Existing tennis rackets lack optimal designs for achieving high spin performance, control, and feel at impact, particularly in high-speed swings.

Innovation Solution

A racket design featuring a plain weave structure with spin facilitating zones, comprising high-tension and low-tension transverse threads arranged to allow for enhanced deformation and restoration of longitudinal threads, thereby imparting overspin to the ball.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high-tension transverse threads are used throughout the face, then control performance is improved, but spin performance deteriorates due to restricted longitudinal thread deformation

Engineering Contradiction:
Improvecontrol performanceVSAvoidspin performance
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies different thread tension configurations to different regions of the racket face. Specifically, it creates spin facilitating zones with alternating high-tension and low-tension transverse threads, while other regions maintain uniform high-tension threading. This local differentiation allows longitudinal threads in spin zones to deform freely for enhanced spin, while maintaining overall control performance through the high-tension regions.

Inventive Principle:
Principle #3Local quality

2Object-generated harmful factors

If low-tension transverse threads are used throughout the face, then spin performance is improved, but control performance and durability worsen

Engineering Contradiction:
Improvespin performanceVSAvoidcontrol performance
Core Design Contradiction:
Object-generated harmful factorsVSReliability

Solution Approach 1:

Instead of uniformly applying low-tension threads across the entire face, the patent strategically places low-tension transverse threads only in specific spin facilitating zones. These zones are positioned where spin generation is most beneficial, while the remainder of the face maintains high-tension threading for control and durability. This selective application resolves the contradiction between spin enhancement and overall performance maintenance.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If uniform thread tension is used across the face, then manufacturing simplicity is maintained, but spin performance deteriorates due to lack of deformation zones

Engineering Contradiction:
Improvethreading simplicityVSAvoidspin performance
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The patent segments the racket face into distinct functional zones: spin facilitating zones with alternating high-low tension transverse threads, and control zones with uniform high-tension threading. This segmentation allows the face to exhibit different mechanical characteristics in different regions, enabling enhanced spin performance in specific areas without compromising overall manufacturing feasibility. The segmented approach balances complexity introduction with performance benefits.

Inventive Principle:
Principle #1Segmentation

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 design achieves excellent spin performance, control, and a soft feel at impact, with adjustable thread tensions enhancing launch speed and durability.

Implementation Method 1

a third string which is a low-tension cross string... the plain weave structure includes one or more spin facilitating zones... allow for enhanced deformation and restoration of longitudinal threads, thereby imparting overspin to the ball

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4647134A1racket
Publication Date: 2025.11.12 SUMITOMO RUBBER INDUSTRIES LTD
  • EP4647134A1 patent drawingFigure 1
  • EP4647134A1 patent drawingFigure 2
  • EP4647134A1 patent drawingFigure 3

AI summary

A face of a tennis racket includes a plain weave structure including a plurality of longitudinal threads, a plurality of high-tension transverse threads 36, and a plurality of low-tension transverse threads 38. The tennis racket includes a spin facilitating zone 46. The spin facilitating zone 46 includes: (1) a first high-tension transverse thread 36; (2) a second high-tension transverse thread 36; and (3) an odd number of low-tension transverse threads 38 positioned between the first high-tension transverse thread 36 and the second high-tension transverse thread 36. The spin facilitating zone includes no other high-tension transverse thread 36 positioned between the first high-tension transverse thread 36 and the second high-tension transverse thread 36.