Golf-club shafts having selectable-stiffness tip regions, and golf clubs comprising same
View Patent ↗The subject golf clubs have a shaft and clubhead. The shaft has a tip-end coupled to the clubhead, a butt-end, a reduced-EI portion located adjacent the tip-end, and a remaining portion extending between the butt-end and the reduced-EI portion. The portions are coupled together at an interface. The remaining portion exhibits a respective rate of stiffness reduction as a function of distance from the butt-end. The reduced-EI portion is typically shorter than and has less stiffness than the remaining portion. The reduced-EI portion exhibits a respective rate (which can be zero) of stiffness reduction as a function of distance toward the tip-end. These rates can be similar or different. The interface can exhibit a greater rate in stiffness reduction than the other portions.
1. A golf club, comprising:
a shaft including a butt-end, a tip-end, a length extending from the butt-end to the tip-end, and an interface at a location along the length, the length including a major-length portion extending from the butt-end to the interface and a minor-length portion extending from the interface to the tip-end, the minor-length portion being shorter and having less stiffness than the major-length portion; and
a clubhead mounted to the tip-end;
wherein the butt-end includes a grip;
the major-length portion exhibits a substantially uniform first rate of stiffness reduction with distance from the butt-end to the interface;
the minor-length portion exhibits less stiffness than the major-length portion;
the interface comprises a juncture of the major-length and minor-length portions and exhibits a rate of stiffness reduction that is greater than the first rate in a direction toward the tip-end;
wherein the major-length portion is made of a first material, the minor-length portion is made of a second material, and the interface comprises a junction between the first and second material;
wherein at least one of the first and second materials is a metal;
wherein the minor-length portion is no greater than eight inches in length.
2. The golf club of claim 1 , wherein the minor-length portion exhibits a second rate of stiffness reduction with distance from the interface to the tip-end.
3. The golf club of claim 2 , wherein the second rate is substantially uniform not equal to the first rate.
4. The golf club of claim 1 , wherein:
the clubhead is of a metal-wood; and
the clubhead has a stated loft of 8.5 to 14 degrees.
5. The golf club of claim 1 , wherein the clubhead is detachable from the tip-end.