US 8,301,418 B2 · Process for designing rugged pattern on golf ball surface

Abstract

A golf ball 2 has a large number of craters 8. A rugged pattern is formed on the golf ball 2 by the craters 8. A process for designing the rugged pattern includes the steps of: assuming a plurality of states; assuming a large number of cells on a spherical surface; assigning any one of the plurality of states to each cell; assigning, as an attribute, any one of INSIDE, OUTSIDE and BOUNDARY to the each cell based on the state of the each cell and states of a plurality of cells located adjacent to the each cell; assuming craters based on the attributes of the large number of cells; and updating the attribute of the each cell so as to enlarge the areas of the craters, based on the attribute of said each cell and the attributes of the plurality of cells located adjacent to the each cell.

A computer-implemented method of designing a golf ball having a large number of craters on the surface thereof, wherein a pattern of the craters on said golf ball are designed by a process comprising the steps of:

assuming a plurality of states;
assuming a large number of cells on a spherical surface;
assigning any one of the plurality of states to each cell;
assigning, as an attribute, any one of INSIDE, OUTSIDE and BOUNDARY to said each cell based on the state of said each cell and states of a plurality of cells located adjacent to said each cell;
assuming craters based on the attributes of the large number of cells;
and
updating the attribute of said each cell so as to enlarge the areas of the craters, based on the attribute of said each cell and the attributes of the plurality of cells located adjacent to said each cell;
and
wherein the golf ball has a difference dR obtained by the steps of:
(1) assuming a line connecting both poles of the golf ball as a first rotation axis;
(2) assuming a great circle which exists on a surface of a phantom sphere of the golf ball and is orthogonal to the first rotation axis;
(3) assuming two small circles which exist on the surface of the phantom sphere of the golf ball, which are orthogonal to the first rotation axis, and of which the absolute value of a central angle with the great circle is 30′;
(4) defining a region, of the surface of the golf ball, which is obtained by dividing the phantom sphere at the two small circles and which is sandwiched between the two small circles;
(5) determining 30240 points, on the region, arranged at intervals of a central angle of 3° in a direction of the first rotation axis and at intervals of a central angle of 0.25° in a direction of rotation about the first rotation axis;
(6) calculating a length L1 of a perpendicular line which extends from each point to the first rotation axis;
(7) calculating a total length L2 by summing 21 lengths L1 calculated based on 21 perpendicular lines arranged in the direction of the first rotation axis;
(8) determining a maximum value and a minimum value among 1440 total lengths L2 calculated along the direction of rotation about the first rotation axis, and calculating a fluctuation range Rh by subtracting the minimum value from the maximum value;
(9) assuming a second rotation axis orthogonal to the first rotation axis assumed at the step (1);
(10) assuming a great circle which exists on the surface of the phantom sphere of the golf ball and is orthogonal to the second rotation axis;
(11) assuming two small circles which exist on the surface of the phantom sphere of the golf ball, which are orthogonal to the second rotation axis, and of which the absolute value of a central angle with the great circle is 30°;
(12) defining a region, of the surface of the golf ball, which is obtained by dividing the phantom sphere at the two small circles and which is sandwiched between the two small circles;
(13) determining 30240 points, on the region, arranged at intervals of a central angle of 3° in a direction of the second rotation axis and at intervals of a central angle of 0.25° in a direction of rotation about the second rotation axis;
(14) calculating a length L1 of a perpendicular line which extends from each point to the second rotation axis;
(15) calculating a total length L2 by summing 21 lengths L1 calculated based on 21 perpendicular lines arranged in the direction of the second rotation axis;
(16) determining a maximum value and a minimum value among 1440 total lengths L2 calculated along the direction of rotation about the second rotation axis, and calculating a fluctuation range Ro by subtracting the minimum value from the maximum value;
and
(17) calculating the difference dR between the fluctuation ranges Rh and Ro, and
wherein the absolute value of the difference dR is 2.5 mm or less.

25 more elements

Description10,890 words

Summary2,425 words

#This application claims priority on Patent Application No. 2008-261266 filed in JAPAN on Oct. 8, 2008. The entire contents of this Japanese Patent Application are hereby incorporated by reference.

#1. Field of the Invention

#The present invention relates to golf balls. Specifically, the present invention relates to processes for designing a rugged pattern on a golf ball surface.

Brief description of the drawings52 figures

#FIG. 1 is a schematic cross-sectional view of a golf ball according to one embodiment of the present invention;

#FIG. 2 is a an enlarged front view of the golf ball in FIG. 1;

#FIG. 3 is a flow chart of a designing process according to one embodiment of the present invention;

Detailed description7,658 words

#The following will describe in detail the present invention based on preferred embodiments with reference to the accompanying drawings.

#Golf ball 2 shown in FIG. 1 includes a spherical core 4 and a cover 6. On the surface of the cover 6, a large number of craters 8 are formed. Of the surface of the golf ball 2, a part other than the craters 8 is a land 10. The golf ball 2 includes a paint layer and a mark layer on the external side of the cover 6 although these layers are not shown in the drawing. A mid layer may be provided between the core 4 and the cover 6.

#The diameter of the golf ball 2 is 40 mm or greater and 45 mm or less. From the standpoint of conformity to the rules established by the United States Golf Association (USGA), the diameter is more preferably 42.67 mm or greater. In light of suppression of air resistance, the diameter is more preferably 44 mm or less and particularly preferably 42.80 mm or less. The weight of the golf ball 2 is 40 g or greater and 50 g or less. In light of attainment of great inertia, the weight is preferably 44 g or greater and more preferably 45.00 g or greater. From the standpoint of conformity to the rules established by the USGA, the weight is preferably 45.93 g or less.

Facts

Application

12/553,702Filed 3 Sep 2009

Priority

JP 2008-2612668 Oct 2008

Published

US 2010/0088071 A18 Apr 2010

Granted

30 Oct 2012

Term ends

2 Apr 2031

Estimated · how

20 years from earliest known nonprovisional domestic filing plus recorded patent term adjustment, including 576 days of adjustment. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification4 codes

G06F 30/10
Computer-aided design [CAD]: geometric CAD
G06F 30/00
Computer-aided design [cad]
G06F 2113/22
Details relating to the application field: moulding
G06F
Computing and data processing

Timeline

8 Oct 2008Priority claimedJP 2008-261266
3 Sep 2009Application filedUS 12/553,702
15 Sep 2009Assigned to Sri Sports Limitedassignment of assignor's interest
8 Apr 2010PublishedUS 2010/0088071 A1
30 Oct 2012GrantedUS 8,301,418 B2
12 Apr 2018Assigned to Dunlop Sports Co. Ltd.change of name
17 Apr 2018Assigned to Sumitomo Rubber Industries, Ltd.merger
12 Oct 2026TodayWithin its term
2 Apr 2031Term endsEstimated, includes 576 days of adjustment

Process for designing rugged pattern on golf ball surface

Life of this patent

Process for designing rugged pattern on golf ball surface

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims4

Description10,890 words

Drawings

Classification4 codes

Life of this patent

Description10,890 words