| 摘要 |
PROBLEM TO BE SOLVED: To provide spike cleats for a baseball where a gripping force to soil of the ground on either of front and back surfaces is larger than a gripping force obtained by a projection plate having flat front and back surfaces. SOLUTION: The front and back surfaces 1a and 1b of the projection plate 1 are provided with recessed surface parts A<SB>1</SB>, A<SB>2</SB>and A<SB>3</SB>where a resisting force of the plate surface is larger than a resisting force of the flat surface, when the projection plate 1 is intended to be moved orthogonally to the plate surface, in a state where a plan view shape of the projection plate 1 is formed in a corrugated form and the projection plate 1 is penetrated through the soil of the ground. COPYRIGHT: (C)2004,JPO
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