Multi-piece Golf Ball Hardness Gradient for Spin Control

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Solution Overview

Problem

Multi-piece golf balls with outer-hard and inner-soft hardness distribution achieve low spin rates on driver shots but compromise controllability on approach shots, leading to suboptimal performance in both scenarios.

Innovation Solution

A multi-piece golf ball design featuring a spherical center covered by at least two envelope layers and a cover, where the material hardness of the spherical center (H0), first envelope layer (H1), and second envelope layer (H2) satisfy the equation H0 > H1 > H2, with H2 being the lowest, to control spin rates effectively on driver and approach shots.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If an outer-hard and inner-soft hardness distribution is adopted in the golf ball, then the spin rate on driver shots is lowered and flight distance is increased, but the spin rate on approach shots is also lowered and controllability deteriorates

Engineering Contradiction:

Improvespin rate on driver shotsVSAvoidcontrollability on approach shots

Core Design Contradiction:

SpeedVSEase of operation

Solution Approach 1:

The golf ball is divided into multiple envelope layers (first envelope layer and second envelope layer) with different hardness characteristics. The first envelope layer has higher hardness to control spin on driver shots, while the second envelope layer has lower hardness to maintain spin on approach shots, allowing each layer to serve a specific function that resolves the contradiction between low driver spin and high approach spin controllability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the golf ball are assigned different hardness properties. The outer portion (second envelope layer) has lower hardness to interact with the clubface during approach shots and generate high spin, while the inner portion (first envelope layer) has higher hardness to resist deformation during driver shots and reduce spin. This local differentiation of material properties allows the ball to exhibit context-dependent performance.

Inventive Principle:

Principle #3Local quality

2Length of moving object

If an outer-hard and inner-soft hardness distribution is adopted in the golf ball, then flight distance on driver shots is improved, but controllability on approach shots deteriorates

Engineering Contradiction:

Improveflight distance on driver shotsVSAvoidcontrollability on approach shots

Core Design Contradiction:

Length of moving objectVSEase of operation

Solution Approach 1:

The golf ball is segmented into multiple envelope layers with differentiated hardness properties. The first envelope layer (higher hardness) contributes to reducing spin on driver shots for extended flight distance, while the second envelope layer (lower hardness) maintains high spin on approach shots for precise controllability, thus resolving the contradiction between flight distance and controllability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The golf ball features local quality variations in hardness across different layers. The second envelope layer's lower hardness enables high spin generation during approach shots for controllability, while the first envelope layer's higher hardness prevents excessive spin on driver shots, allowing the ball to achieve both long flight distance and precise controllability in different shot scenarios.

Inventive Principle:

Principle #3Local quality

3Speed

If the material hardness of the spherical center is higher than the envelope layers, then the spin rate on driver shots is reduced, but the overall resilience and durability are compromised

Engineering Contradiction:

Improvespin rate on driver shotsVSAvoidresilience and durability

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The golf ball structure is segmented into a spherical center and multiple envelope layers, each with optimized hardness characteristics. The envelope layers are designed with lower hardness than the center to achieve low spin on driver shots, while the multi-layer configuration maintains overall resilience and durability by distributing stress and preventing energy loss, thus resolving the contradiction between spin reduction and reliability maintenance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The golf ball employs a composite material structure where the spherical center and envelope layers are made from materials with different hardness properties. This composite construction allows the envelope layers to reduce spin on driver shots through their lower hardness, while the combination of materials across layers maintains the ball's overall resilience and durability, overcoming the trade-off between spin control and reliability.

Inventive Principle:

Principle #40Composite materials

Data Source

PatentUS10543402B2Multi-piece golf ball

Publication Date: 2020.01.28 SUMITOMO RUBBER INDUSTRIES LTD

AI summary

An object of the present invention is to provide a golf ball showing low spin rate on driver shots and high spin rate on approach shots. The present invention provides a multi-piece golf ball comprising a spherical center, at least two envelope layers covering the spherical center, and a cover covering the envelope layers, wherein the envelope layers comprise at least a first envelope layer covering the spherical center, and a second envelope layer covering the first envelope layer, a material hardness (H0) of the spherical center, a material hardness (H1) of the first envelope layer, and a material hardness (H2) of the second envelope layer satisfy an equation of H0>H1>H2, and the material hardness (H2) of the second envelope layer is lowest among the material hardness of the center constituent material and material hardness of envelope layer constituent materials.