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Golf club head and golf club

Golf club head and golf club description/claims

1. Field of the Invention

The present invention relates to a wood golf club head and a golf club and, more particularly, to a wood golf club head having a loft angle of not more than 15° and a golf club.

2. Description of the Related Art

In a golf club, the shape of the head greatly influences playability, directionality of a hit ball, and the like. There have been provided and proposed heads with a variety of designs in order to improve ball catchability, playability, directionality of a hit ball, and the like by adjusting a face progression (FP) representing the length from the axis line of the shaft to the leading edge of the face, the center of gravity position, a gravity depth (VZG) representing the length from the leading edge of the face to the center of gravity in the depth direction, a gravity depth (ZG) representing the length from the face to the center of gravity, a loft angle, a gravity length (GL) representing the length from the axis line of the shaft to the center of gravity, the height of the sweet spot, and the like.

In general, as a factor of ball catchability, a small face progression (FP) is considered to provide high ball catchability and a large FP is considered to provide low ball catchability. In this specification, high ball catchability means that the head rotation is encouraged through impact so that it is easy to hook (difficult to slice) a ball, and low ball catchability means that the head rotation is not encouraged through impact so that it is easy to slice (difficult to hook) a ball. The center of gravity depth (VZG) represents a relative center of gravity depth in the head. Generally, a larger center of gravity depth tends to provide better ball catchability.

When ball catchability is excessively high or low, the playability becomes poor and the directionality of the hit ball becomes unstable. These phenomena are considered to occur because the behavior of the golf club head during a swing has a lack of stability and a stable head rotation cannot be controlled. A factor for controlling stable head rotation is assumed to be determined from the relationship between the hitting point, center of gravity position, and shaft axis, but no distinct relationship has been found.

As a golf club head that is focused on the FP value, one with an FP value falling within a range of 7 mm to 20 mm (both inclusive) has been proposed (for example, see Japanese Patent Laid-Open No. 11-178958). Another golf club head that is focused on the center of gravity depth (ZG) has also been proposed (for example, Japanese Patent Laid-Open No. 2002-210045).

With a design in which only the value of one factor such as the FP value or ZG value is defined, the behavior of the golf club head during a swing cannot be stabilized. Therefore, stable head rotation and ball catchability cannot be controlled, resulting in poor playability. Accordingly, a player cannot selectively hook or slice a ball. In addition, the directionality of the hit ball is unstable.

It is an object of the present invention to provide a wood golf club head and a golf club in which the behavior of the golf club head during a swing is stable, stable head rotation can be controlled, and playability and directionality of a hit ball are excellent.

According to an aspect of the present invention, there is provided a wood golf club head having a loft angle of not more than 15°, wherein a progression length FP from a leading edge of a face to an axis line of a shaft axis and a horizontal length VZG from the leading edge of the face to a center of gravity of the head in a depth direction satisfy the following expression; −2<VZG−2×FP<2. A golf club comprising such a wood golf club head is also provided.

The FP preferably satisfies 12 mm<FP<20 mm, and more preferably 12 mm<FP<17 mm.

Further features of the present invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawing).

FIGURE is a side view of a golf club head 1 according to an embodiment of the present invention.

• Provisional Patent
• Utility Patent

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