Golf club shaft

Abstract

Golf club shafts are flexible. The flexibility varies from very flexible for ladies to very stiff for men professionals. The midpoint of flexibility also varies depending on the level of skill of the golfer. The flexibility of a shaft is controlled primarily by variations in material, diameter and thickness of its walls. The flexibility is approximately equal in all directions from the axis. This article discusses only the flexibility in two planes around the bottom edge of the club head face as defined below: Parallel—The plane parallel with the flight of the ball Perpendicular—The plane perpendicular to the flight of the ball The shaft bends in both the parallel and the perpendicular planes (and various combinations) during the swing. Figures I, II & III from Ben Hogan's “Power Golf” shows the enormous amount of club head movement (around the line through the center of the grip) during various stages of the golf swing. Figure I shows that the club head is pointed toward the ground and the flex is primarily in the perpendicular plane at the top of the golf swing. Figure II shows that the flex is primarily in the parallel plane at this point in the down swing.

Description

The shaft is not pointed at the heel of the clubhead at impact See Figure III. We learn by “trial and error” where to aim the club shaft to get a solid hit. This direction changes as we vary the speed of our swing. The amount of clubhead movement also varies with each club as the length and weight are different.

The flexibility in the plane in line with the flight of the ball reduces the shock of impact and increases the club head speed at impact to give added distance to the flight of the ball. See Figure II.

The shaft also flexes in the perpendicular plane because the golf club head is not in line with the shaft and because extreme force is exerted on the shaft at the top of the backswing. See Figure I.

This flexibility in the perpendicular plane allows the club head to be above or below the ball at the time of impact and makes it difficult to hit the ball in the center (sweet spot) of the club. This accounts for some of the fat, topped and shanked shots.

SPECIFICATION

This patent describes changes in the design of a golf club shaft that will give less flexibility in the perpendicular plane than in the parallel plane.

This can be accomplished in many different ways. Listed below are a few possibilities: See Figure IV.

1—Oval rather than round along portions or entire length of shaft

2—Ribs inside of shaft along portions or entire length of shaft

3—Ribs on outside of shaft along portions or entire length of shaft

4—Partition inside of shaft along portions or entire length of shaft

Since some of the above changes would also have an effect on the parallel flexibility, it would be necessary to make compensating changes in order to maintain the same range of flexible shafts now available.

Claims

1. If a golf club shaft is designed and constructed to give less flexibility in the perpendicular plane than the parallel plane, the probability of hitting the ball on the sweet spot of the club head will be increased.