Acushnet Company (Fairhaven, MA) has developed golf balls with modified density gradients among the inner layers to produce a desired high or low moment of inertia and controlled spin rate. The golf ball has three or more inner layers in addition to a cover, and the density of the inner layers is selected such that the layers inside the cover have a density progression from the core to the cover or from the cover to the core.
Reallocating the density or specific gravity of the various layers or mantles in the ball is an important means of controlling the spin rate of golf balls. In some instances, weight from the outer portions of the ball is redistributed to the center of the ball to decrease the moment of inertia thereby increasing the spin rate, according to inventors Derek A Ladd, Michael J. Sullivan, Antonio U. DeSimas and Edmund A. Hebert. The methods of making golf balls in which the spin rates can be increased or decreased according to the specific gravity of the ball are detailed in U.S. Patent 7,651,415, issued on Janaury 26th.
The core and/or core layers (or other intermediate layers) are adjusted to a target specific gravity to enable the ball to be balanced. For a 1.68-inch diameter golf ball having a ball weight of about 1.61 oz, the target specific gravity is about 1.125. The target specific gravity will vary based upon the size and weight of the golf ball. The specific gravity is adjusted to the desired target through the use of inorganic fillers. Preferred fillers used for compounding the inner layer to the desired specific gravity include: in particular nano or hybrid materials of tungsten, zinc oxide, barium sulfate and titanium dioxide.
The spin rate of golf balls is the end result of many variables, one of which is the distribution of the density or specific gravity within the ball. Spin rate is an important characteristic of golf balls for both skilled and recreational golfers. High spin rate allows the more skilled players, such as PGA professionals and low handicapped players, to maximize control of the golf ball. A high spin rate golf ball is advantageous for an approach shot to the green. The ability to produce and control back spin to stop the ball on the green and side spin to draw or fade the ball substantially improves the player's control over the ball. Hence, the more skilled players generally prefer a golf ball that exhibits high spin rate.
On the other hand, recreational players who cannot intentionally control the spin of the ball generally do not prefer a high spin rate golf ball. For these players, slicing and hooking are the more immediate obstacles. When a club head strikes a ball, an unintentional side spin is often imparted to the ball, which sends the ball off its intended course. The side spin reduces the player's control over the ball, as well as the distance the ball will travel. A golf ball that spins less tends not to drift off-line erratically if the shot is not hit squarely off the club face. The low spin ball will not cure the hook or the slice, but will reduce side spin and its adverse effects on play. Hence, recreational players prefer a golf ball that exhibits low spin rate.
On the other hand, recreational players who cannot intentionally control the spin of the ball generally do not prefer a high spin rate golf ball. For these players, slicing and hooking are the more immediate obstacles. When a club head strikes a ball, an unintentional side spin is often imparted to the ball, which sends the ball off its intended course. The side spin reduces the player's control over the ball, as well as the distance the ball will travel. A golf ball that spins less tends not to drift off-line erratically if the shot is not hit squarely off the club face. The low spin ball will not cure the hook or the slice, but will reduce side spin and its adverse effects on play. Hence, recreational players prefer a golf ball that exhibits low spin rate.
Acushnet Company, comprised of the Titleist, FootJoy and Cobra golf brands, is committed to providing both serious and recreational golfers alike with products and services of superior performance and quality. A nearly $1.4 billion operating company of Fortune Brands (NYSE: FO), Acushnet is a leading manufacturer and marketer of golf balls, golf clubs, golf shoes and golf gloves
