Golf ball
AssigneeSumitomo Rubber Industries, Ltd.
InventorsMasaya Tsunoda, Masahide Onuki
Life of this patent
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Abstract
There is provided a golf ball with a low spin rate, a high launch angle and an increased flight distance, characterized in a ratio of a primary natural frequency of the golf ball in a direction in which the ball deforms (in a longitudinal direction) (fn) and a primary natural frequency of the ball in a vibration mode in a direction of torsion, i.e., a ratio fc/fn provided in a range: 2.22≦(fc/fn)≦2.45. This relationship is satisfied by a golf ball for example having a core formed of a plurality of layers and having a center smaller in complex modulus than the core's outermost layer or having a cover with a complex modulus adjusted to have a large value.
Claims5
A golf ball, comprising at least three layers having a solid core and a cover, said cover having a complex modulus of from 140 MPa to 400 MPa, wherein said golf ball provides a ratio of a primary natural frequency of the golf ball in a direction in which the ball deforms (in a longitudinal direction) (fn) and a primary natural frequency of the ball in a vibration mode in a direction of torsion (fc), i.e., a ratio (fc/fn) in a range:
- 2.22≦(fc/fn)≦2.45 and
- wherein both the values of (fc) and (fn) are between 400 and 4000 Hz.
A golf ball comprising a solid core and a cover, said solid core being formed of a plurality of layers and having a center smaller in complex modulus than an outermost layer of said core, and wherein
- said golf ball has a center smaller in complex modulus than said cover, and wherein said cover is greater in complex modulus than the core adjacent thereto, wherein said cover has a complex modulus that is from 140 MPa to 400 MPa and wherein (fc) and (fn) are from 400 to 4000 Hz, and wherein (fn) is a primary natural frequency of the ball in a direction in which the ball deforms, and (fc) is a primary natural frequency of the ball in a vibration mode in a direction of torsion.
Dependencies are inferred from the claim text.