Golf club shaft

摘要

A golf club shaft is manufactured using a plurality of prepreg sheets a1 to a8. The plurality of prepreg sheets a1 to a8 includes full length sheets a2 to a7 disposed all over in a shaft axis direction and partial sheets a1 and a8 partially disposed in the shaft axis direction. The number of plies is substantially an integer in all the full length sheets a2 to a7. The full length sheets a2 to a7 include four or more bias sheets a2 to a5. Circumferential winding start positions of the bias sheets a2 to a5 are dispersed in four or more positions. Preferably, the circumferential winding start positions of the full length sheets a2 to a7 are dispersed in five or more positions.

主权项

1. A golf club shaft manufactured using a plurality of prepreg sheets,
wherein the plurality of prepreg sheets comprises full length sheets disposed all over in a shaft axis direction and a partial sheet or partial sheets partially disposed in the shaft axis direction; the number of plies is substantially an integer in all the full length sheets; the full length sheets comprise four or more bias sheets; circumferential winding start positions of the bias sheets are dispersed in four or more positions; the bias sheets have two base sheets (a first base sheet and a second base sheet) and two adjusting sheets (a first adjusting sheet and a second adjusting sheet); the two base sheets have an absolute fiber angle θb of 40 degrees or greater and 50 degrees or less; the two adjusting sheets have an absolute fiber angle θt of 15 degrees or greater and 75 degrees or less, and the absolute fiber angle θt is less than the absolute fiber angle θb; and if the circumferential winding start position of the first base sheet is defined as Pa; the circumferential winding start position of the second base sheet is defined as Pb; the circumferential winding start position of the first adjusting sheet is defined as Pc; and the circumferential winding start position of the second adjusting sheet is defined as Pd, each of the positions Pa, Pb, Pc, and Pd corresponds to any one of the following four circumferential positions P1, P2, P3, and P4 in a one-to-one manner: the circumferential position P1: 0 degrees; the circumferential position P2: 75 degrees or greater and 105 degrees or less; the circumferential position P3: 165 degrees or greater and 195 degrees or less; and the circumferential position P4: 255 degrees or greater and 285 degrees or less.