| 摘要 |
<p>PURPOSE:To improve the spin and repulsion properties in the case where a ball is hit in the central part of a gut surface by delineating respectively plural regions in the specific positions in the major axis and minor axis direction of the gut surface and respectively specifying the ratios of the respective mean lengths of the meshes in these regions. CONSTITUTION:The first and secondary boundary lines P1, P2 are set in the respective positions of 1/15 and 2/5 of the overall length L of the major axis Y on both sides of the major axis Y from the central point O of the gut surface 4 to delineate the first and second regions A1, A2, of the major axis Y. The ratio 11/12 between the respective mean values 1, 12 of the lengths in the major axis Y direction of the meshes M formed at the intersected points of the respective gut K, J in the respective directions of the major axis Y and the minor axis X in the respective regions A1, A2 is specified to 1.2 to 2.0. Further, the third and fourth boundary lines P3, P4 are set in the respective positions of 1/ 5 and 2/ 5 of the overall length W on both sides of the minor axis X. The ratio m1/m2 between the respective mean values m1, m2 of the lengths in the minor axis X direction of the meshes M in third and fourth regions B1, B2 delineated by these lines is set at 1.2 to 2.0.</p> |
