| 摘要 |
<p>PURPOSE:To mold a golf ball having no great circular paths crossing no dimples by dividing a metal mold into a mold having parts corresponding the great circular paths and the other molds. CONSTITUTION:An intermediate mold 12 corresponds to a part of a golf ball including a great circle C on the outer periphery of a horizontal diameter passing through the center point of the golf ball. The intermediate mold 12 has an annular form having upper and lower openings and formed of a shape memory alloy. The intermediate mold 12 has the largest circumferential part in the vertical center part of a mold surface 12b curved inward toward upper and lower openings. An upper mold 11 has a hollow part 11a formed of an arcuate recess opened in the lower end face, and a lower mold 13 has a hollow part 13a formed of an arcuate recess opened in the upper end face. The upper and lower molds 11, 13 are made of carbon steel. The metal mold is heated to 100 deg.C or more in the molding by assembling the upper, intermediate and lower molds 11, 12, 13. Then, the intermediate mold 12 is deformed into a memory shape so that the ends of the openings coincide with each other to connect the mold surfaces continuously with each other for constituting the spherical surface of the golf ball.</p> |
