Patent Application
20170319916
The present invention relates to golf clubs and in particular to drivers, fairway woods and hybrids having an improved club head, striking face configuration.
The Characteristic Time, hereinafter CT, has been commonly known as measuring the “spring-like” or “trampoline” effect of a driver, fairway wood or hybrid face or more formally as a measurement of the Coefficient of Restitution of those faces. The CT is recognized in terms of micro seconds and will be referred to hereinafter as u sec.
A wide variety of club head configurations, weighting structures, and striking face features have been proposed and presented to the golfing marketplace to achieve increased performance with these clubs.
However, the focus on increasing the spring-like or trampoline effect for the club face has been in terms of making the center or near center of the face having the highest CT. This is because tour professionals hit the center or very near center of the face. Another reason the CT is the highest in the center of the face is a byproduct of historical manufacturing construction.
Although most drivers have titanium faces, most other conventional metal wood type golf clubs and hybrid golf clubs are made with steel faces because of lower material and manufacturing costs. The clubs with steel faces provide little spring-like or trampoline effect as compared to similar clubs with titanium faces. In addition, various attempts have been made, as represented in prior art patents, to improve the striking face configuration of golf clubs for better performance.
U.S. Pat. Nos. 6,659,884, 6,659,885, 7,131,912, 7,273,421 and 7,481,717 to Knuth are directed to golf club heads having an improved face configuration using different thicknesses and parabolic shaped sections to improve performance across the face.
U.S. Pat. Nos. 5,830,084, and 6,368,234 assigned to Callaway and U.S. Pat. No. 5,954,596 assigned to Ping, among others, are directed to metal wood golf clubs having a striking face with various thicknesses.
The United States Golf Association, USGA, is the governing body of golf in the United States and publishes the Rules of Golf that includes equipment standards in order that golf clubs are deemed conforming. Non-conforming clubs may not be used in all professional and most non-professional tournaments or for golfers to obtain and maintain a USGA handicap index.
One of the USGA rules relating to equipment limits the transfer of energy to a golf ball due to the spring-like or trampoline effect of the striking face of a golf club. This rule seeks a limit on this effect to restrict the distance that golf clubs are able to hit a golf ball in order to preserve the challenges of existing golf courses. The limit is embodied in their former Coefficient of Restitution, COR, rule which is a measurement of the energy transfer in a collision of two objects. The USGA established a COR limit of 0.830 on driver, fairway wood and hybrid golf club faces, which means that if more than 83% of the energy is transferred in the collision of the driver head with a golf ball, the club head would be deemed non-conforming with the USGA rules.
In the early 2000s the USGA established the Characteristic Time, CT, test to determine whether a golf club head conformed to or exceeded the COR limitation. The CT test includes positioning the head so a pendulum arm with a sensor strikes the face at a variety of locations at the center and off-center. The speed of the pendulum as it bounces off the face determines the CT value. It was determined a CT measurement of 257 microseconds, 257 u sec, corresponds to a COR of 0.830 and this established the CT limit for anywhere on the face. Any driver, fairway wood or hybrid golf that had a CT measurement in excess of 257 u sec anywhere on the face was non-conforming under the USGA rules.
Recently the USGA amended the CT rule to identify an area it called the Impact Area as having a width of 42.67 mm or 1.68 inches in the center of the face of a driver, fairway wood and hybrid and a height from the crown down to the sole with the exception of 6.35 mm within the sole and crown excluded. Refer to
The present invention relates to a driver, fairway wood and hybrid club having an improved striking face design used with these clubs in an improved club face characteristic time, CT. These clubs are the first to use a face that is 257 u sec or less in the entire Impact Area but has areas that are greater than 257 u sec in the Outside Impact Area but are not over 275 u sec anywhere in that area.
The club heads of the present invention are formed with a titanium or a titanium alloy striking face that produces a higher CT than conventional steel face clubs in the Impact Area up to 257 u sec. The club face of the present invention also produces a CT in the Outside the Impact Area that exceeds 257 u sec and the absence of any CT over 275 u sec. The CT values of the present invention are accomplished as a result of different zones of variable thickness in the faces as identified below.
It will be appreciated that there are different zones of height, width and thickness for the driver, fairway woods and hybrids. The reason is the preferable widths, heights and thicknesses of each of these clubs are different and those differences can affect the spring-like or trampoline effect of those faces because a larger face, by virtue of its greater size will have a higher CT for the same thickness in the relatively same location.
It will be further appreciated that the same object of the invention could be achieved if areas identified below in the Impact Area or the Outside the Impact Area have one uniform thickness or multiple thicknesses and one or more different shapes of uniform or variable thicknesses, including the absence of a rectangular shape. The average thicknesses of the areas described below have been found to achieve the object of the present invention even if one or more different shapes are used that overlap part or all of the areas described below. As a result, a golf ball struck with the club achieves less loss of energy off the club face when the ball is struck on areas both within the Impact Area and Outside the Impact Area but within the USGA allowable limit.
The benefit of this design creates CT values between 250 and 257 u sec in the center and other areas in the Impact Area and CT values between 257 and 275 u sec in the Outside the Impact Area where there is typically a larger loss of energy as a result of an off-center, miss-hit of the golf ball against the striking face of the club head that results in loss of both distance and accuracy.
It will be appreciated the improved striking faces of the present invention may be used with drivers having a variety of different lofts that are typically within a range of 8 to 13 degrees, fairway woods having lofts that are typically within a range of 13 to 21 degrees and metal hybrid golf clubs that have lofts typically between 15 and 26 degrees.
Among the objects of the present invention is the provision of a metal golf club that has areas of CT values at or near the USGA limits in the Impact Area and CT values higher than 257 u sec and approaching 275 u sec in the Outside Impact Area.
This and other objects will be appreciated with reference to the following specification and accompanying drawings.
Referring to
The striking face 104 preferably in the present embodiment is wide and extends between the toe 112 and heel 113 of the club head 100 with CT values up to the USGA's 257 u sec limit in the Impact Area 115 and greater than 257 u sec and approaching the 275 u sec limit in the Outside Impact Areas 116 and 117.
It will be appreciated that the above example of a preferred embodiment and the thicknesses disclosed are not limiting but may be altered in keeping within the concept of the invention.
