In May 1990 Spalding obtained a patent1 for a golf ball with 492 dimples arranged in an icosahedron dimple pattern that was modified so that the equator of the ball did not pass through any dimples. This produced a golf ball that was aerodynamically symmetric in flight. The 492 dimples on this ball each had a diameter of 0.126 inches and a depth of 0.0092 inches. The % coverage was calculated to be 69%. This resulted in a ball that tended to drop down at a steeper angle so that it held the green better than a standard ball which had a flatter trajectory.
Spalding 492 dimple golf ball2
The 1990 patent with 492 dimples was a continuation of an application originally filed Jan. 14, 1986. Since a patent application must be filed within one year of the invention, the earliest date for this invention must be about Feb. 1985. Therefore I was not surprised to see Spalding golf balls with 492 dimples on the June 1985 USGA conforming list. Spalding golf balls that have this 492 dimple pattern on the June 1985 list are: Top-Flite 492 Spalding USA, Top-Flite Plus Spalding 492, Top-Flite Plus Spalding 492 (orange cover), and Top-Flite Plus Spalding 492 (yellow cover). These golf balls continue to appear on the USGA lists every year until 1993. A fifth ball with 492 dimples, Top-Flite Spalding 492 with logo, appeared on the USGA lists from 1988 to 1993.
I do not have any of these golf balls in my collection but I have one Spalding ball with 492 dimples, ball #504, Spalding Plus, Extra Distance. This ball first appeared on the 1995 USGA list Spring Edition.
#504 Spalding Plus, Extra Distance golf ball
The USGA lists began including the golf ball color, compression, construction, cover, and number of dimples in 1990. In 1990 Spalding listed 3 balls with 336 dimples, 38 balls with 332 dimples, 14 with 422 dimples, and 5 with 492 dimples. By 1995 there were no balls listed with either 336 or 332 dimples, 22 balls with 410 dimples, 96 balls with 422 dimples and 10 balls with 492 dimples.
Next time I will discuss the Spalding golf ball technology that has 422 dimples on the cover.
References
- Terence Melvin, R. Dennis Nesbit, US 4,925,193, May 15, 1990, filed Apr. 10, 1989, priority Jan. 14, 1986.
- The equator of the golf ball is labeled with the letter A.