| 摘要 |
<p>PURPOSE: To improve a resilience characteristic by setting a flattening rigidity per unit width to within a specified range at least at one point of hitting zone at the top end of a baseball bat made from FRP. CONSTITUTION: At a hitting zone la ranging from 50mm to 250mm under the top end of a baseball bat 1 made from FRP, a flattening rigidity per unit width at least at one point is set more than 2.5kgf/mm and less than 3.5kgf/mm. A thickness of the hitting zone 1a is set more than 4.0mm and less than 7.0mm. An orientation angle of reinforced fiber at a hitting zone 1a is set more than 0 deg. and less than 45 deg.. For a baseball bat made from a titanium alloy, at a hitting zone 1a ranging from 50mm to 250mm under the top end of a bat 1, a flattening rigidity per unit width at least at one point is set more than 2.5kgf/mm and less than 3.5kgf/mm.</p> |
