Golf Ball Core Hardness Gradient for Driver Distance and Iron Spin
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Solution Overview
Problem
Existing golf balls face a trade-off between improved flight distance on driver shots and spin performance on middle iron shots due to the hardness gradient between the surface and center of the spherical core, where reducing the spin rate on driver shots also lowers the spin rate on middle iron shots.
Innovation Solution
A golf ball design with a specific hardness distribution across eight equal parts of the spherical core, adhering to strict Shore C hardness relationships, balances resilience and deformation to enhance flight distance on driver shots while maintaining good spin performance on middle iron shots.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the hardness difference between surface hardness and center hardness of the spherical core is increased to lower spin rate on driver shots, then flight distance on driver shots is improved, but spin rate on middle iron shots is lowered
Solution Approach 1:
The spherical core is divided into eight equal parts along the radius, with hardness values measured at each segment (center, 12.5%, 25%, 37.5%, 50%, 62.5%, 75%, 87.5%, and surface). This segmentation allows independent control of hardness at different radial positions, enabling the surface hardness to be sufficiently hard for driver distance while maintaining appropriate hardness in inner regions for iron shot spin performance.
Solution Approach 2:
Different regions of the spherical core are assigned different hardness values according to specific formulae relationships. The surface region has higher hardness to reduce driver spin and increase distance, while inner regions maintain controlled hardness to preserve iron shot spin rate. This local differentiation of material properties resolves the contradiction between driver performance and iron shot performance.
2Length of moving object
If the hardness difference between surface hardness and center hardness is controlled to lower spin rate on driver shots, then flight distance is improved, but the hardness distribution becomes more complex
Solution Approach 1:
The hardness distribution is controlled by changing the physical parameter of hardness at different radial positions according to specific mathematical formulae. By defining relationships between hardness values at different segments (C0-C8), the patent achieves optimized flight distance while maintaining a manageable and systematic hardness distribution pattern that can be reproduced in manufacturing.
Data Source
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AI summary
An object of the present disclosure is to provide a golf ball having excellent flight distance on driver shots and good spin rate on middle iron shots. The present disclosure provides a golf ball comprising a spherical core and a cover, wherein a hardness difference (C1-C0), a hardness difference (C2-C1), a hardness difference (C3-C2) and a hardness difference (C4-C3) are more than 0 and 6.0 or less, a hardness difference (C5-C4) is 5.0 or more, and a hardness difference (C6-C5), a hardness difference (C7-C6) and a hardness difference (C8-C7) are more than 0 and 3.5 or less where C0 (center), C1, C2, C3, C4, C5, C6, C7 and C8 (surface) are a Shore C hardness at each point from the center obtained by dividing a radius of the spherical core into equal eight parts