The present invention is directed to a golf club head having a face angle that is twisted from high to low such that the face angle high on the face is open relative to the face angle at the center, and the face angle low on the face is closed relative to the face angle at the center. This twist eliminates the left/right dispersion produced when hitting the ball high or low on a normal clubface.
With a normal golf club head, shots that are hit high on the face (with the face square to the intended target and club head path) tend to hook and land left of the target, while shots hit low on the face tend to slice and land right of the target. By precisely twisting the face as described, these trends can be decreased or eliminated. Thus, shots will more consistently land on target, regardless of how high or low they are hit on the face. For example, when a typical PGA Tour Player with about a 110 to 115 mph swing speed hits a golf ball with a prior art driver, such as a Titleist® 905T, the ball will land about ten yards right of the target when struck 0.5″ low on the face, and will land 5 yards left of the target when struck 0.5″ high on the face. Incorporating the face twist designed for this swing speed according to the present invention (approximately 0.5° closed at a point 0.5″ low, and 0.25° open at a point 0.5″ high), both shots (and all those in between) land on the centerline. For golfers having reduced swing speeds, the twist angles are designed into the face to correspond to the lower swing speed. For example, a golfer with a swing speed of only 90 mph, would have a twist angle built into the face of this driver of about 0.3° closed at the lower position and 0.1° open at the higher position. Thus, the present invention contemplates measuring a user's club head speed or ball speed and selecting the proper amount of face twist for that golfer.
While it would be obvious that the twisting effect of the present invention will cause the loft angle to change very slightly from the heel to the toe, any drop in distance will be almost negligible (approximately 1-2 yards).
The immediate use for the twist concept would primarily be for metal wood and hybrid clubs. The concept would work equally as well for iron type clubs, however since the rules of golf do not allow a curved face for irons, the present invention is primarily addressed to metal woods and hybrids.
A golf club head with a twisted face angle is depicted by the reference 10 in
Players are fitted to a particular type of club by using such variables as head speed, club loft angle, club shaft flex, and average club face thickness, golf ball weight, and golf ball spin. Once a particular type of club head is selected for the player, the concept of the present invention can be utilized to improve and refine the club selection by providing a simple and accurate method of selecting a club head based on selection of the proper twisted front face angle for that particular player's swing speed. This will allow off-center hits that are either high or low to be compensated for the “gear effect” regardless of the swing speed. Just as each golf club is fitted to the swing characteristics of the player, each player may now also be fitted with the proper twist angle for his/her swing speed.
The method of the present invention is generally as follows. First, a measurement of the golfer's swing characteristic is made. In the most preferred embodiment, the golfer's club head speed is taken. Based on the players club head speed, the golfer is fitted to the golf club having the proper twist angle characteristics. Each club head will have its own unique twist angles for a range of swing speeds.
The golfer's club head speed can be determined using any available device. Preferably, a device such as the Mini-Pro 100 Golf Swing Analyzer, the Pro V Golf Swing Analyzer or the Pro III Golf Swing Analyzer available from GolfTek, 0201 1st Street, Lewiston, Id. 83501; the DeadSolid Golf Simulator from DeadSolid Golf, 1192 Sathers Dr., Pittston, Pa. 18640; or the Double Eagle 2000 from Par T Golf, 7310 Smoke Ranch Rd., Suite H, Las Vegas, Nev. 89128 is used to measure the club head speed at impact during a golfer's swing. More particularly, the golfer's swing speed is measured using a golf club having a length between 43.5 to 46 inches. Most preferably, the golfer's club head speed is measured using a club of 44 inches long. Examples of the classification of swing speeds could be from very high to low, such as professional, high, medium, low or senior speeds.
Thus, in the manner of carrying out the present invention the appropriate club head twist angles are determined for every club head so designed. Examples of the twist angle variations can be shown for a Titleist® 905R driver as follows:
Consider a high handicap player (i.e., 12-18) with a measured club head speed of 85 miles per hour, which would characterize the golfer under the present invention as having a medium swing speed. When such a golfer is equipped with a Titleist® 905R driver, having about a 11.5° loft and a R or S stiff flex shaft, preferably an R flex, to obtain optimum driving performance, the twist angles ø and β designed by the present invention for the tangents at T
Now consider a low handicap player (i.e. 0-5) having a swing speed of 110 to 115 mph, which would be a professional speed. For this level player, the Titleist® 905R driver would preferably have a loft no higher than 9.5° and the shaft would preferably be of a stiff flex. For this golfer the twist angles ø and β for the tangents at T
Swing speeds between those stated in the above examples would be basically extrapolated on a linear basis. The main concept is to have twist angles that match the player's club speed for every golf club driver.
Although the present invention can be utilized by golfers of any skill level, the most preferred embodiment set forth in detail herein is most appropriate for medium to high handicap golfers. Furthermore, it will be understood that the claims are intended to cover all changes and modifications of the preferred embodiment of the invention, herein chosen for the purpose of illustration, which do not constitute departures from the spirit and scope of the invention.