Golf club head

1. A golf club head comprising:

a head body;

a weight member attached to said head body; and

fixing means for fixing said weight member at any one of a plurality of attachment positions of said head body,

wherein the plurality of attachment positions are located in a sole portion of said head body and on a virtual cylindrical surface having an axis of a shaft to be attached to the golf club head as a center.

2. The head according to claim 1 , wherein a center-of-gravity length of said head body without said weight member attached thereto is positioned on the virtual cylindrical surface.

3. The head according to claim 1 , wherein said fixing means comprises:

a plurality of first screw portions which are provided in the sole portion and define the plurality of attachment positions; and

a second screw portion which is provided in said weight member and threadably engages with said first screw portion.

4. The head according to claim 1 , further comprising a rail portion which is formed along a virtual line on the virtual cylindrical surface in said sole portion and defines the plurality of attachment positions,

wherein said fixing means fixes said weight member at a given position on said rail portion.

5. The head according to claim 4 , characterized in that said rail portion comprises:

a groove open at a lower part thereof, which is formed along the virtual line and forms an accommodation space to accommodate said weight member;

a partitioned chamber closed at an upper part thereof, which is formed along the virtual line in an upper portion of said groove;

a partitioning portion which is provided between said groove and said partitioned chamber and vertically partitions the space in said groove from said partitioned chamber; and

a slit which is formed along the virtual line in said partitioned chamber and makes the space in said groove communicate with said partitioned chamber, and

said fixing means comprises:

a slide member which is accommodated in said partitioned chamber such that it can move along the virtual line and connected to said weight member through said slit; and

screw portions which are respectively provided in said slide member and said weight member, and threadably engage with each other.

6. The head according to claim 1 , wherein a change amount of center-of-gravity angle of the golf club head caused by a difference between the attachment positions used to fix said weight member is not less than 3 degrees.

7. The head according to claim 1 , further comprising a plurality of said weight members having different weights.

8. The head according to claim 1 , further comprising a vibration damping member which is inserted between said head body and said weight member at the attachment position.

9. The head according to claim 8 , wherein said vibration damping member is integrally provided in said weight member.

10. The head according to claim 1 , wherein said weight member is fixed to said sole portion of said head body,

said sole portion has a recess formed in the attachment position of said weight member, and

a depth of said recess is set such that a lowest portion of said weight member fixed to said head body is positioned above a lowest portion of said sole portion.

11. The head according to claim 1 , wherein all attachment positions in the sole portion are located on the virtual cylindrical surface.

12. A golf club head comprising:

a head body; and

a weight member attached to said head body at any one of a plurality of attachment positions of said head body,

wherein the plurality of attachment positions are located in a sole portion of said head body and on a virtual cylindrical surface having an axis of a shaft to be attached to the golf club head as a center.

13. The head according to claim 12 , wherein all attachment positions in the sole portion are located on the virtual cylindrical surface.