| 摘要 |
<p>PROBLEM TO BE SOLVED: To enable a golfer to carry out training to roll a ball like in putting of golf or a gate ball indoors while preventing noise without requiring special implements. SOLUTION: A fluid object 2 consisting of liquid, such as water or lubricating oil, or grains, such as sand or beads, having a flow property is sealed into a hollow spherical body 1 and a fiber layer is formed on the outer peripheral surface of the spherical body by adhering or applying fibers consisting of synthetic fibers or natural fibers. The centroid 4a of the flowable object 2 sealed into the spherical body 1 exists on the perpendicular line passing the center 1a of the spherical body and below the center 1a in a static state.</p> |
