Spalding Icosahedron Pattern

Last time¹ I reported that Spalding golf balls #537, MOLITOR Spalding and #29, Spalding XL Top-Flite both had 332 dimples arranged in the Acushnet Icosahedron Dimple Pattern². Upon closer examination I found that ball #537 also had a new feature that ball #29 did not. Ball #537 contained 12 dimples that were slightly smaller (0.12 inch diameter) compared to the other 320 dimples (0.14 inch diameter). Six smaller dimples were positioned at each polar region as shown below. The equatorial region was unchanged. This difference in the size of 12 dimples was very subtle and I did not recognize this at first. Let’s call this the Spalding Icosahedreon Dimple Pattern.

I was unable to find a patent for this Spalding Icosahedron Dimple Pattern³. In order to get a patent and invention must be novel, not obvious, and useful. As far as I could tell no one ever disclosed a golf ball with an icosahedron dimple pattern consisting of 320 large and 12 small dimples. So this was novel. But Dunlop Limited Company filed a US patent⁴ for a golf ball that had four sizes of dimples in 1976. So it would have been obvious to make a golf ball with more than one size of dimples. Also, I was unable to find any information that indicated that the new dimple pattern was useful.

The ball ‘Spalding Molitor’ is listed on the USGA Conforming List from August 5, 1975 until February 15, 1979 when two separate entries appeared. The first entry was “Spalding Molitor (All markings on seam) and the second entry was ‘Spalding Molitor (Molitor on pole)’. Ball # 537 in my collection has all the markings on the seam so the correct date of introduction was Feb. 15, 1979 and not Aug. 5, 1975, as reported last time.

#537 MOLITOR SPALDING

(first appears on the Feb. 15, 1979 USGA list)

I think that the Spalding Molitor golf ball with Molitor on the pole was produced from 1975 to 1979 with the Acushnet Icosahedron dimple pattern, 332 dimples of one size. If anyone has a Spalding MOLITOR ball with MOLITOR on the pole in their collection, I would love to hear from you about the nature of the dimple pattern.

Here are other Spalding golf balls in my collection that have the Spalding Icosahedron Dimple Pattern.

#245, XL TOP-FLITE 3, Spalding

(proposed date of introduction late 1979)

#524, XL TOP-FLITE 3, Spalding orange cover

(first appears on Mar 15, 1982 USGA list)

#333, XL TOP-FLITE 1, *Spalding

(first appears on the Feb. 16, 1981 USGA list)

The XL TOP-Flite golf balls #245, #524, and #333 are similar to golf ball #29¹ in that all the names appear on the seam of the golf ball. However, ball #29 uses an older italics font⁵ for the XL Top-Flite while balls #245, 524, and 333 all use a newer bold font for the XL Top-Flite name. For this reason I think that the ball #29 was introduced before ball #245.

In order to accurately date golf balls, one needs to not only find the date that the golf ball first appears on the USGA list, but also examine the location of the name on the ball, what type font is used, determine the dimple pattern and sizes of the dimples, and be aware of any pertinent US patent literature that might help to determine the date.

Next time we will report our results on additional Spalding US dimple pattern patents and how these an be used to obtain the date of introduction of Spalding golf balls in the 1980’s.

References

(1) See earlier post published on Jan. 6, 2022, “The Spalding DOT Mystery”

(2) GB 1,381,897, Golf Ball Dimple Spatial Relationship. Oct. 12, 1972, priority date Mar. 20, 1972, published Jan. 29, 1975.

(3) https://patents.google.com\

(4) Michael Shaw, Robert C. Haines, US 4,142,727, Mar. 6, 1979, filed Aug. 20, 1976.

(5) See ball #26 in my earlier post published on Nov. 11, 2021. “1975-1978 Titleist Acushnet DT”.