Field of the Invention
The present invention relates to a golf club head.
Description of the Related Art
A golf club head includes a hosel portion in which a shaft is inserted. The arrangement of the hosel portion may affect the performance of the golf club head. For example, in some cases, the weight of the hosel portion affects the center of gravity of the golf club head. Japanese Patent Laid-Open No. 2000-5351 discloses a golf club head that reduces the weight of the hosel portion and also provides a reinforcing plate to prevent its strength from lowering.
In addition, for example, the shape of the hosel portion may affect the air resistance of the golf club head. In a club such as a driver with a relatively high head speed, the air resistance of the hosel portion may affect the head speed. Each of Japanese Patent Laid-Open Nos. 2009-279373, 2005-237535, and 2-277474, Japanese Utility Model Laid-Open No. 60-128663, U.S. Pat. Nos. 8,758,157, 8,568,247, 5,674,136, and 5,575,725, and U.S. Patent Application Publication No. 2005/032584 discloses a golf club head that reduces the air resistance by the shape of the hosel portion. To the contrary, U.S. Pat. No. 5,827,132 discloses a golf club head that increases the air resistance by the shape of the hosel portion and prompts face rotation.
When reducing the air resistance, it is effective to reduce the air resistance by the shape of the hosel portion, as in Japanese Patent Laid-Open Nos. 2009-279373, 2005-237535, and 2-277474, Japanese Utility Model Laid-Open No. 60-128663, U.S. Pat. Nos. 8,758,157, 8,568,247, 5,674,136, and 5,575,725, and U.S. Patent Application Publication No. 2005/032584. However, the hosel portion may become bloated, and the weight of the golf club head may increase on the heel side. This readily moves the center of gravity of the golf club head to the heel side, resulting in disadvantage in designing the center of gravity.
According to an aspect of the present invention, there is provided a golf club head comprising: a hosel portion in which a shaft is inserted, the hosel portion being provided on a heel side of the golf club head; and an extended portion that extends from the hosel portion to a back side of the golf club head, wherein the extended portion includes a distal end portion on a face portion side and a rear end portion on the back side, out of a heel-side portion and a toe-side portion of the hosel portion, the distal end portion is connected to the heel-side portion, and the rear end portion is located on a toe side with respect to the distal end portion.
Further features of the present invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawings).
The golf club head 10 forms a hollow member. The peripheral walls of the golf club head 10 constitute a face portion 11 that forms a face (striking face), a crown portion 12 that forms the upper portion of the golf club head 10, a sole portion 13 that forms the bottom portion of the golf club head 10, and a side portion 14 that forms the portion between the crown portion 12 and the sole portion 13. The golf club head 10 also includes a hosel portion 15 in which a shaft is inserted and fixed, and an extended portion 16.
In
The golf club head 10 is a golf club head for a driver. However, the present invention is applicable to various kinds of golf club heads including a hosel portion such as wood type golf club heads including a fairway wood other than drivers, utility (hybrid) golf club heads, other hollow golf club heads, and iron type heads.
The golf club head 10 can be made of a metal material. Examples of the metal material are a titanium-based metal (for example, titanium alloy 6Al-4V-Ti), stainless steel, and a copper alloy such as beryllium copper.
The golf club head 10 can be assembled by joining a plurality of parts. For example, the golf club head 10 can be formed from a body member and a face member. The body member forms the peripheral portions including the crown portion 12, the sole portion 13, the side portion 14, the hosel portion 15, the extended portion 16, and the face portion 11. An opening is formed at part of the portion corresponding to the face portion 11. The face member is joined to the opening of the body member.
The hosel portion 15 and the extended portion 16 will be described with reference to
In this embodiment, the hosel portion 15 has a cylindrical shape. However, the hosel portion 15 may have another tubular shape such as an elliptic cylindrical shape. A concave portion 15a is formed in the toe-side outer surface of the hosel portion 15. In this embodiment, the concave portion 15a has a circular shape (spherical shape). However, it may have a polygonal shape. When the concave portion 15a is provided, the separation position of an airflow at impact can be changed to the back side as compared to a case without the concave portion 15a, and the air resistance caused by the presence of the hosel portion 15 can be reduced. The concave portion 15a has a depth of, for example, 0.1 mm to 1 mm and a diameter of, for example, 1 mm to 10 mm. The concave portion 15a can be provided, in the outer surface of the hosel portion 15, at a position within the hosel diameter in the face-back direction with respect to the toe-side end where the airflow readily separates as the center. The toe-side end position is preferable, as in this embodiment. In this embodiment, only one concave portion 15a is provided. However, a plurality of concave portions may be provided. When providing a plurality of concave portions, the plurality of concave portions can be provided in a direction parallel to the axial direction of the hosel portion 15, in the face-back direction, or in both directions.
The extended portion 16 extends from the hosel portion 15 to the back side in the face-back direction. In this embodiment, the extended portion 16 is integrated with the hosel portion 15 and the side portion 14. However, the extended portion 16 may be fixed so as to be detachable from the golf club head 10. In this case, the extended portion 16 may be interchangeable to allow the user to select the extended portion 16 according to his/her taste from a plurality of types of extended portions 16 of different specifications.
In this embodiment, the extended portion 16 is a plate-shaped member having a thickness T. The thickness T can be even or uneven as a whole. A structure other than the plate shape may be employed. From the viewpoint of weight reduction, the extended portion 16 is preferably so thin as to stand a wind pressure. For example, the maximum thickness is 0.5 mm to 15 mm, which is preferably equal to or smaller than the radius of the hosel portion 15. The extended portion 16 has a triangular outer shape. However, a circular shape, a polygonal shape, or a shape including an arcuate portion may be employed. However, the structure of the extended portion 16 is not limited to this.
The extended portion 16 includes a distal end portion 16a on the side of the face portion 11, and a rear end portion 16b on the back side. The distal end portion 16a has a height h in a direction parallel to the axial direction of the hosel portion 15. The height h is, for example, 5 mm to 50 mm. The height of the extended portion 16 gradually decreases from the distal end portion 16a to the rear end portion 16b. In the rear end portion 16b, the height from the surface of the side portion 14 is 0. In this embodiment, the bottom portion of the extended portion 16 is connected to the boundary portion between the side portion 14 and the crown portion 12. However, it may be connected to only the side portion 14 or only the crown portion 12. When the extended portion 16 is connected to the side portion 14 or the crown portion 12, the airflow readily smoothly flows from the extended portion 16 to the side portion 14 or the crown portion 12.
If a maximum length L of the extended portion 16 in the face-back direction (the length between the distal end portion 16a and the rear end portion 16b) falls within the range of, for example, 5 mm to 50 mm, the air resistance can be reduced without unnecessarily making the hosel portion large.
Referring to
Referring to
In this embodiment, a heel-side side surface 16c of the extended portion 16 is connected continuously to the outer surface of the hosel portion 15 without any step. This can suppress a turbulent airflow as compared to a case with a step. The side surface 16c is also connected continuously to the outer surface of the side portion 14 without any step. This can also suppress a turbulent airflow as compared to a case with a step.
In this embodiment, a wedge-shaped space 17 is formed between a toe-side side surface 16d of the extended portion 16 and the outer surface of the hosel portion 15. An arrangement that fills the space 17 can also be employed.
The effect of reducing the air resistance of the hosel portion 15 by the extended portion 16 will be described next with reference to
As shown in
In this embodiment shown in
As described above, this embodiment is based on an idea that the airflow F1 flowing onto the crown portion 12 while whirling to the toe side largely affects the increase in the air resistance to the golf club head 10. In this embodiment, the extended portion 16 is arranged on the heel side of the hosel portion 15 as a whole so as to actively guide the airflow on the heel side of the hosel portion 15. On the other hand, the extended portion 16 does not actively guide the airflow on the toe side of the hosel portion 15, placing focus on weight reduction. It is therefore possible to suppress an increase in the weight of the golf club head 10 on the heel side caused by the presence of the extended portion 16 while reducing the air resistance of the hosel portion 15.
In addition, the air resistance caused by the airflow on the toe side of the hosel portion 15 can be reduced by the concave portion 15a in the outer surface of the hosel portion 15. This also contributes to reduction of the air resistance of the hosel portion 15 without increasing the weight.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2014-250299, filed Dec. 10, 2014, which is hereby incorporated by reference herein in its entirety.
Number | Date | Country | Kind |
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2014-250299 | Dec 2014 | JP | national |
Number | Name | Date | Kind |
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4747599 | Antonious | May 1988 | A |
4948140 | Antonious | Aug 1990 | A |
5120061 | Tsuchida | Jun 1992 | A |
5575725 | Olsavsky | Nov 1996 | A |
5674136 | Gorse | Oct 1997 | A |
5827132 | Bamber | Oct 1998 | A |
7169063 | Tuttle | Jan 2007 | B2 |
7713138 | Sato et al. | May 2010 | B2 |
8177659 | Ehlers | May 2012 | B1 |
8568247 | Ehlers | Oct 2013 | B1 |
8758157 | Ehlers | Jun 2014 | B1 |
20050032584 | Van Nimwegen | Feb 2005 | A1 |
20160067562 | Beach | Mar 2016 | A1 |
Number | Date | Country |
---|---|---|
02-277474 | Nov 1990 | JP |
2000-005351 | Jan 2000 | JP |
2005005351 | Jan 2000 | JP |
2005-237535 | Sep 2005 | JP |
2005237535 | Sep 2005 | JP |
2009-279373 | Dec 2009 | JP |
Number | Date | Country | |
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20160166892 A1 | Jun 2016 | US |