Patent ID: 6110056
Filing Date: 2000-08-29
Classification: A63B,Y10S

Abstract:
A golf club group comprising a plurality of golf clubs of the same number including a swinger golf club and a hitter golf club having shafts of approximately the same flexibility, each shaft having a length between a tip end and a butt end and including a plurality of bias layers and a plurality of straight layers formed to be shaped into a tapered circular configuration having a diameter that gradually increases towards the butt end of the shaft, each of said plurality of bias layers having reinforcing fibers arranged obliquely to an axial direction of the shaft, each of said plurality of straight layers having reinforcing fibers arranged parallel to the axial direction of the shaft,wherein said swinger golf club has a shaft with a distribution of flexural rigidity over the length thereof that is represented by relation to a reference curve resulting from plotting units of flexural rigidity against units of shaft length for an assumed shaft in which said plurality of straight layers of the swinger golf club have a constant thickness from the tip end to the butt end, such that flexural rigidity in a portion of the swinger golf club shaft length from a position Q, that is spaced about 300 mm from the butt end, to the butt end, is represented by a plot region of the reference curve on or lower than a line tangent to the reference curve at the position Q, and said hitter golf club has a shaft with a distribution of flexural rigidity over the length thereof that is represented by relation to a reference curve resulting from plotting units of flexural rigidity against units of shaft length for an assumed shaft in which said plurality of straight layers of the hitter golf club have a constant thickness from the tip end to the butt end, such that flexural rigidity in a portion of the hitter golf club shaft length from the position Q to the butt end is represented by a plot region of the reference curve higher than a line tangent to the reference curve at the position Q.