Ferrule and golf club
A ferrule includes: an upper body which projects from an upper end face of a hosel portion; an inserted portion which is provided to project downwards from the upper body to be inserted into an interior of a hosel hole; and a groove which is provided circumferentially on an outer circumferential surface of the inserted portion, wherein a lower end portion of the inserted portion has a diameter which is smaller than that of an upper side of the inserted portion than the groove.
1. A ferrule and a hosel for a golf club comprising:
a hosel; and
a ferrule, wherein the ferrule comprises:
an upper body which projects from an upper end face of said hosel;
a diametrically reduced surface tapered upwards so that a central portion takes an upper position;
an inserted portion which is provided to project downwards from the upper body to be inserted into an interior of a hole in said hosel; and
a groove which is provided circumferentially on an outer circumferential surface of the inserted portion, wherein:
a lower end portion of the inserted portion has a diameter which is smaller than that of an upper side of the inserted portion above the groove;
the diametrically reduced surface is disposed between a lower end of the upper body and the inserted portion; and
a space is formed between the diametrically reduced surface and an upper end of said hosel.
2. The ferrule and hosel according to claim 1 , wherein
a lower end side of the inserted portion below the groove has an isodiametric cylindrical shape.
3. The ferrule and hosel according to claim 2 , wherein
a diameter of a lower outer circumferential surface of the inserted portion is smaller by 0.1 to 0.5 mm than a diameter of an upper outer circumferential surface of the inserted portion.
4. The ferrule and hosel according to claim 1 , wherein
at least the lower end portion of the inserted portion is tapered so as to reduce the diameter as it extends towards a lower end.
5. A golf club comprising:
a head including a hosel hole;
a shaft mounted in the hosel hole; and
a ferrule including:
an upper body which projects from an upper end face of a hosel portion of the head;
a diametrically reduced surface tapered upwards so that a central portion takes an upper position;
an inserted portion which is provided to project downwards from the upper body to thereby be inserted into an interior of the hosel hole; and
a groove which is provided circumferentially on an outer circumferential surface of the inserted portion, wherein
a lower end portion of the inserted portion has a diameter which is smaller than that of an upper side of the inserted portion above the groove;
the diametrically reduced surface is disposed between a lower end of the upper body and the inserted portion; and
a space is formed between the diametrically reduced surface and an upper end of the hosel portion.
6. The golf club according to claim 5 , wherein:
the hosel hole is formed into a small diameter hole portion on a deeper side and into a large diameter hole portion on an entrance side, and a step portion is provided between the small diameter hole portion and the large diameter hole portion; and
the step portion is shaped so as to expand diametrically as it extends towards the entrance side.
7. The golf club according to claim 6 , wherein:
an adhesive flows into between the outer circumferential surface of the inserted portion and the large diameter hole portion;
a part of the adhesive enters the groove; and
the adhesive is set so that the shaft and the ferrule are fixedly bonded to the hosel portion.
8. The golf club according to claim 6 , wherein:
an inner circumferential edge of the step portion has an arc shape in cross-section.