JPH0220264B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a golf club of the type having an iron head for use on tees and fairways, and more particularly, to a golf club that responds to off-center impacts of a golf ball. This relates to improving the performance of a set of clubs.

Although the golfer controls the swing of the golf club head, it is now well known that upon impact the club head behaves as if it were a free mass with a specific velocity. Most of this mass's energy is applied to the ball within about 0.5 milliseconds, after which the ball is pressed against the face of the club and rebounds away from the face of the club, restoring its spherical shape.

Ideally, the center of impact between the club head and the ball should be below the center of gravity so that the club head twists over the ball upon impact. This twist increases the backspin on the ball that is normally generated due to the loft of the club head.

To better understand the backspin normally exerted on a ball, the club head should be thought of as a wedge driven between the ground and the ball, rather than as a mallet used to hit the ball in crotchet or polo. During the time the ball is in contact with the club head, the ball tends to slide up the face of the club and the friction imparts backspin, which is the amount of backspin the ball would have if it were to roll away from the golfer on the ground. This is the opposite of the rotation that would occur.
Therefore, by the time the ball rebounds and leaves the club surface, a significant amount of backspin has been imparted to the ball.

This backspin is desirable to stop the ball from rolling forward on the ground, especially when the ball lands on the green. The torsion effect described above is created by normally designing the club head so that the center of impact is below the center of gravity.
Such twisting action increases the normally generated backspin. However, the torsional action sometimes produces club head vibrations that are transmitted through the shaft and irritate the golfer's hands. To make matters worse, the vibrations generated in the club head also prevent normal deflection of the end of the shaft upon impact. This deflection is desirable because as the ball bounces off the face of the club, the deflected shaft straightens and applies additional force to the ball.

It would be desirable to avoid coupling the torsional action of the club head to the shaft. Club head vibrations would then have no effect on shaft deflection. The club head has more freedom to twist, which provides greater control over backspin. Control of this backspin can be accomplished by raising or lowering the center of impact on the face of the club with each stroke, as desired.

In accordance with the present invention, the head of an iron golf club is separated from the club shaft by a narrow neck between the body and a hosel connecting the body to the shaft. This neck is thinner in its midsection than the hosel and, of course, narrower than the body, so it acts as a torsion bar that absorbs the torsional forces of the club head, thus having less effect on clubshaft deflection. Become.

The invention will be best understood from the following description taken in conjunction with the accompanying drawings.

1 and 2, a conventional club head 10 is shown striking a ball 12, with the center of impact between the club head and the ball being at a point 14 below the club head's center of gravity CG. As the club head moves into the ball, the ball tends to slide up the slope 15 of the club head, but due to friction the ball actually rolls up, thereby imparting backspin to the ball. The impact with the ball also produces a clockwise twisting motion of the club head about the center of gravity as shown, which imparts counterclockwise rotation of the ball due to the gearing effect between the club face and the ball surface. This club head twist therefore increases the backspin that is otherwise being imparted to the ball.

The amount of twist produced in the club head is a function of how far below the center of gravity the center of impact is.
Since this is a factor that the golfer can control, and controlled backspin is desired by the golfer, it is desirable to have a twist in the club head that does not affect the club shaft 16.

As mentioned above, the lower end of the club shaft
As shown in the diagram, the shaft deflects back on impact, storing energy that is released as the ball leaves the club head, causing the deflected shaft to rebound forward. Thus, the ball leaves the club head not only with additional backspin due to the torsional action of the club head, but also with additional velocity.

Both of these effects are more clearly shown in FIG. 2, which is a front view of the club head 10 of FIG. 1 in a prior art golf club (of the general form shown in FIG. 1). As shown, they are connected by a thick neck 18 which is used to connect the body 20 of the club head to the hosel 22. The upper edge 24 of the club head and the sole 26 extend to a neck 18 which curves upwardly to meet the hosel.

As can be seen from the two views shown in Figures 1 and 2, the net is intentionally made very strong.
Thus, the body 20 of the club head (hereinafter sometimes referred to as the "club head itself") is rigidly connected to the hosel 22 by the very strong neck 18. As a result, the twisting of the club head itself causes the hosel to pivot forward, thereby causing the shaft 16 to curve near the hosel.

When impacting the ball below the center of gravity, the first
As shown, the curvature is in the same direction as the deflection of the shaft, but still causes vibrations that are transmitted through the shaft to the golfer's hands. Worse still, club head twist and shaft deflection are impeded by the rigid neck 18, preventing optimal ball backspin and velocity from being achieved. When impacting a ball above its center of gravity to produce forward or topspin, the club head is twisted in the opposite direction to that shown in Figure 1, ie, counterclockwise, to bring the hosel into normal deflection of the shaft. In this case, severe vibrations can be generated in the club head and shaft. The present invention separates the club head itself from the hosel so that twisting of the club head itself does not affect the normal deflection of the shaft and optimal spin (back or forward) is imparted to the ball.

3, 4, and 5, there are shown front, rear, and end views of a head 30 for an 8 iron, the body 32 being connected to a hosel 34 by a narrow neck 36. The upper edge 38 extends over at least the notched portion of the club face;
It then slopes downward to merge with the upper curved portion 40 of the neck. The sole 42 extends the entire length of the club head and merges with the lower curved portion 44 of the neck. The upper and lower curved parts are the middle part 4
6 to define the narrowest neck. That is, the cross-section of the neck in this intermediate portion 46 has a maximum dimension that is less than the diameter of the hosel 34. Thus, the net 36 functions as a torsion bar and the head 3
When the body 32 of the 0 is twisted in one direction and the hosel is untwisted or twisted in the opposite direction, it twists about the center of the intermediate section 46.

This twist moves the ball at a very high velocity (approximately 160
This occurs only under the tremendous force generated by the club head impacting at a speed of 100 km/h). middle part 4
6 has a smaller cross section than the rest of the narrow neck, the body 32 of the club head will twist about an axis 48 passing through the center 47 of this intermediate section and the center of gravity CG of the club head 30.
Thus, to achieve a torsion bar effect that isolates the torsion of the body 32 of the club head 30 from the hosel 34, the narrow neck 36 is further tapered at its intermediate portion 46 such that its maximum transverse dimension is less than the diameter of the hosel and its The smallest dimension (seen in Figure 6) is made to be considerably smaller.

Figures 7a, 8a, and 9a show the No. 2, No. 5, and pitching wedge club heads of a correlating set of golf clubs, each of which has a thinner tip as described with reference to Figures 3-6 for the No. 8 iron. It is equipped with netsuku. Figures 7b, 8b, and 9b are the 7th
Figures 8a, 8a and 9a show end views of the club head of Figures 8a and 9a, respectively.

While specific embodiments of the invention have been illustrated and described,
It should be recognized that many modifications and variations thereof will readily occur to those skilled in the art. Accordingly, the claims should be construed to cover such modifications and changes.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating the twisting action of a typical prior art club head impacting a ball. FIG. 2 is a front view of the conventional prior art club head of FIG. FIG. 3 is a front view of an iron club head embodying the present invention. 4 is a rear view of the club head of FIG. 3; FIG. 5 is an end view of the club head of FIG. 3; FIG. FIG. 6 is a plan view of the club head of FIG. 3 with the surface in a vertical plane. Figures 7a and 7b are front and end views of a No. 2 club head of a related set embodying the present invention. Figures 8a and 8b are front and end views of a No. 5 club head of a related set embodying the present invention. Figures 9a and 9b are front and end views of a related set of pitching wedge club heads embodying the present invention. 10...Club head, 12...Ball, CG
... Center of gravity, 14 ... Point of impact, 15 ... Inclined surface, 1
6...Clubshaft, 18...Netsuku, 20...
... Main body, 22 ... Hosel, 24 ... Upper edge, 26 ... Sole, 30 ... Club head, 3
2... Main body, 34... Hosel, 36...
... Net, 38 ... Upper edge, 40, 44 ... Curved part, 42 ... Sole, 46 ... Middle part, 47 ...
…center.

Claims (1)

[Scope of Claims] 1. In an iron golf club set in which each club has a correlation, each club has a shaft and a head, and the head of each club receives a main body including a ball-hitting surface and the shaft. a hosel, and a neck connecting the hosel to the body, the neck having a tapered middle section with a non-circular cross section, and the largest dimension of the neck measured in the lateral direction at the middle section being A golf club set having a diameter smaller than that of the hosel, and characterized in that when the club is placed at an address position, an imaginary line connecting the center of the intermediate portion of the neck and the center of gravity of the head is substantially horizontal. 2. The body of the head has a ball-striking surface, a sole, a toe, and an upper edge sloping upwardly from the neck to the toe, and the shape of the neck is defined by a smooth shape extending from the sole to the hosel. Claim 1 characterized in that it is formed by a curved part and a part extending from the upper edge to the hosel and including a curved part in the middle that is steeper than the smooth curved part. Golf club set listed.