The USGA began listing conforming golf balls starting in 1972. Here are three golf balls made by Acushnet Co. in my collection that appear on the 1975-1978 USGA lists.
These three golf balls all have 324 circular dimples arranged in a modified icosahedron pattern (four dimples were removed in each polar region for the name and number). Patents were filed in 1972 in both Great Britain(1) and the United States(2) for this technology.
These golf balls were three piece balls made with a small polymer or liquid center wrapped with a long elastic rubber thread and a thin resilient cover. Balls #1 and #2 had covers made from a soft material called balata. They show cuts and cracks on the surface. Golf Ball #146, which Acushnet first introduced(3) in March 1973, had a new durable cover made from sodium and zinc Surlyn. Spalding claimed this golf ball infringed their patent(4). The infringement trial lasted from 1-1-89 to 2-13-89 and the court ruled that Spalding had proven their claims of infringement. Acushnet stopped making this DT Titleist in 1977.
The Spalding sodium and zinc Surlyn cover first appeared on the Spalding Top Flite golf ball in 1971(3). The Top Flite golf ball had 336 dimples arranged in the ATTI pattern. It was a two piece ball with a large polymer core and a thin resilient cover. The Top Flite golf ball had excellent durability and the new Surlyn cover did not crack when exposed to cold temperatures. It also increased the distance the ball would travel because of the new cover. Here is the 1971 Top Flite golf ball(5) that I have in my collection. This golf ball also appears on the 1975-1978 USGA list.
References
(1) GB 1,381,897, Golf Ball Dimple Spatial Relationship, Oct. 12, 1972, priority date Mar. 20, 1972.
(2) Francis deS. Lynch, John W. Jepson, Robert A. Brown, US 4,729,861, Method of Making Golf Balls, Mar. 8, 1988, priority date Mar. 20, 1972
(3) https://casetext.com/case/spalding-evenflo-companies-inc-v-acushnet-co.
(4) Robert P. Mollitor, US 3,819,768, June 25, 1974, priority date Feb 11, 1972.
(5) M. Hatcher, The History of Spalding Golf Balls (Science Resort (SR) LLC, 2010, 2013, 2014), p. 74-75.
Great book, great site. Are you going to publish older USGA Conforming Ball lists? I am desperately searching for the pre-2002 lists. You mention some in your recent article … thanks for your work.
Thank you for the compliment. Yes I am going to publish older USGA Conforming Ball lists on my site soon. I am still learning how to use WordPress so please be patient.
Great. Thank you so much, and yes: I’ll be patient. I have been searching for many months already, even contacted all kinds of people to no avail so far (USGA, R&A, US Golf Museum and many others). If you ever need information/pictures about European golf balls not available in the US (like the Titleist PTS Series for example), I would be glad to help with what I have.