US20120270683A1 - Golf ball - Google Patents

Golf ball Download PDF

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Publication number
US20120270683A1
US20120270683A1 US12/449,731 US44973108A US2012270683A1 US 20120270683 A1 US20120270683 A1 US 20120270683A1 US 44973108 A US44973108 A US 44973108A US 2012270683 A1 US2012270683 A1 US 2012270683A1
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US
United States
Prior art keywords
golf ball
spherical
sphere
grooves
polyhedron
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US12/449,731
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English (en)
Inventor
Hae Cheon Choi
Jin Choi
Gwang Min Son
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Seoul National University Industry Foundation
Original Assignee
Seoul National University Industry Foundation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Seoul National University Industry Foundation filed Critical Seoul National University Industry Foundation
Assigned to SEOUL NATIONAL UNIVERSITY INDUSTRY FOUNDATION reassignment SEOUL NATIONAL UNIVERSITY INDUSTRY FOUNDATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: SON, GWANG MIN, CHOI, HAE CHEON, CHOI, JIN
Publication of US20120270683A1 publication Critical patent/US20120270683A1/en
Abandoned legal-status Critical Current

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    • A—HUMAN NECESSITIES
    • A63—SPORTS; GAMES; AMUSEMENTS
    • A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
    • A63B37/00—Solid balls; Rigid hollow balls; Marbles
    • A63B37/14—Special surfaces
    • A—HUMAN NECESSITIES
    • A63—SPORTS; GAMES; AMUSEMENTS
    • A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
    • A63B37/00—Solid balls; Rigid hollow balls; Marbles
    • A63B37/0003—Golf balls
    • A63B37/0004—Surface depressions or protrusions
    • A63B37/0007—Non-circular dimples
    • A—HUMAN NECESSITIES
    • A63—SPORTS; GAMES; AMUSEMENTS
    • A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
    • A63B37/00—Solid balls; Rigid hollow balls; Marbles
    • A63B37/0003—Golf balls
    • A63B37/0004—Surface depressions or protrusions
    • A63B37/0007—Non-circular dimples
    • A63B37/0011—Grooves or lines
    • A—HUMAN NECESSITIES
    • A63—SPORTS; GAMES; AMUSEMENTS
    • A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
    • A63B37/00—Solid balls; Rigid hollow balls; Marbles
    • A63B37/12—Special coverings, i.e. outer layer material

Definitions

  • the present invention is related to a golf ball, and more particularly, to a golf ball which has not only an air resistance similar to or smaller than that of a dimpled golf ball, but also a significantly reduced area ratio of grooves relative to the total surface area of the golf ball, thereby achieving an enhanced carry distance and high accuracy in the directionality of putting.
  • a golf ball which has a spherical surface divided into many spherical polygonal faces each being arranged with a circular dimple, has been used for a long time.
  • Such a conventional dimpled golf ball is known to fulfill the symmetry of a spherical surface while achieving a reduced air resistance and consequently an increased carry distance thereof.
  • examples of widely used divisional compositions of a sphere include a spherical icosahedron, a spherical icosi-dodecahedron, a spherical dodecahedron, a spherical octahedron, a spherical hexahedron, a spherical hexa-octahedron, or other further divided spherical polyhedrons having smaller faces.
  • the above mentioned spherical divisional compositions can be actually overlapped with one another except for specially deformed ones.
  • the dimpled golf ball If a golfer hits a dimpled golf ball, the dimpled golf ball is subjected to strong repulsive elasticity by a force applied from the head of a golf club, and simultaneously has a back spin by a loft angle of the club head.
  • the dimpled golf ball has an initial flying velocity of approximately 190 to 300 km/hr and an initial back spin of approximately 2200 to 4500 rpm.
  • dimples of the golf ball act to create a turbulent flow on the surface of the golf ball and in turn, the turbulent flow acts to delay the separation of air streams around the golf ball, thereby reducing a pressure difference between front and rear portions of the dimpled golf ball, and resulting in a reduction of air resistance acting on the golf ball.
  • the area ratio of dimples relative to the total surface area of the golf ball has to be more than 75%. This makes it impossible to achieve a high accuracy in the directionality of putting.
  • a putter 2 generally strikes irregular faces formed with the dimples of the dimpled golf ball 1 and this makes the golf ball 1 to move in a direction slightly different from the golfer's intension. In other words, the golf ball deviates from a hole cup even by an extremely small angular error occurred in putting.
  • the present invention has been made in view of the above problems, and the objective of the present invention is to provide a golf ball which has not only an air resistance similar to or smaller than that of a dimpled golf ball by virtue of net-shaped grooves formed in a spherical surface thereof, but also a significantly reduced area ratio of the grooves relative to the total surface area of the golf ball, thereby achieving an enhanced carry distance and high accuracy in the directionality of putting.
  • a golf ball has net-shaped grooves formed throughout a sphere.
  • an air resistance acting on the golf ball is similar to or smaller than that acting on a dimpled golf ball, thus resulting in an improvement in the carry distance of the golf ball.
  • the present invention as a result of considerably reducing the area ratio of the grooves relative to the surface area of the golf ball, it is possible to reduce the occurrence of putting errors due to the curvature of the grooves, resulting in accurate putting of the golf ball.
  • FIG. 1 is a perspective view illustrating a dimpled golf ball in a putting position
  • FIG. 2 is a sectional view taken along the line A-A of FIG. 1 ;
  • FIG. 3 is a plan view illustrating a golf ball formed with grooves according to an embodiment of the present invention.
  • FIG. 4 is a schematic diagram of the grooves according to one embodiment of the present invention.
  • FIG. 5 is a schematic diagram of the grooves according to another embodiment of the present invention.
  • FIG. 6 is a schematic diagram of the grooves according to yet another embodiment of the present invention.
  • FIG. 7 is a photograph illustrating laboratory equipment having a model of a golf ball according to the present invention.
  • FIG. 8 is a schematic diagram illustrating grooves formed in the surface of the model of the golf ball according to the present invention.
  • FIG. 9 is a photograph illustrating a model of a golf ball according to the present invention, which has grooves and protrusions formed at intervals along the grooves;
  • FIGS. 10 and 13 are graphs illustrating the relationship between the Reynolds number and the air resistance coefficient
  • FIGS. 11 and 14 are graphs illustrating the relationship between the velocity of a golf ball and the air resistance
  • FIG. 12 is a photograph illustrating another model of a golf ball according to the present invention, which has grooves and protrusions continuously formed along the grooves;
  • FIG. 15 is a partial sectional view of a golf ball having grooves and protrusions formed along the grooves according to the present invention.
  • the present invention provides a golf ball in which net-shaped grooves are formed on the outer surface of a sphere.
  • the golf ball in accordance with a preferred embodiment of the present invention includes net-shaped grooves 20 formed on the outer surface of a sphere 10 .
  • the net-shaped grooves 20 may be connected to or separated from one another.
  • each groove 20 can be freely selected among a variety of different shapes so long as all the grooves 20 have a net shape.
  • a spherical regular polyhedron is inscribed in the sphere 10 such that vertexes 31 of spherical regular polygons constituting the spherical regular polyhedron touch on the sphere 10 .
  • certain specific points 33 a on a spherical surface of the sphere 10 are determined such that an included angle ⁇ between a straight line 32 connecting one of the vertexes 31 to a center 11 of the sphere 10 and a straight line 34 connecting the center 11 of the sphere 10 to one of the specific points 33 a has a predetermined value.
  • circular paths 35 are defined on the surface of the sphere 10 by connecting the specific points 33 a to one another.
  • the grooves 20 can be formed along the circular paths 35 .
  • each edge of the regular polyhedron is defined by connecting every two adjacent vertexes 31 to each other via the shortest path on the surface of the sphere 10 .
  • the spherical regular polyhedron may be a spherical regular hexahedron or regular icosahedron, and the included angle ⁇ may be 45 to 80 degrees.
  • the spherical regular hexahedron has six spherical squares and eight vertexes 31
  • the spherical regular icosahedron has twenty spherical regular triangles and twelve vertexes 31 . Therefore, when each groove is formed along one associated circular path 35 defined about each vertex 31 and consequently, eight or twelve grooves are formed in the surface of the sphere 10 such that they are connected to one another, all the grooves 20 occupy only a small area ratio relative to the surface area of the golf ball.
  • the groove be formed on the basis of the included angle ⁇ of 45 to 80 degrees.
  • a spherical regular polyhedron which consists of spherical regular polygons each having a center of gravity 36 , is inscribed in the sphere 10 , and specific points 33 b on the surface of the sphere 10 are determined such that an included angle ⁇ between a straight line 37 connecting one of the centers of gravity 36 to the center 11 of the sphere 10 and a straight line 38 connecting the center 11 of the sphere 10 to one of the specific points 33 b has a predetermined value. If the specific points 33 b are determined, circular paths 39 connecting the specific points 33 b to one another are defined on the surface of the sphere 10 .
  • the grooves 20 can be formed along the circular paths 39 .
  • the spherical regular polyhedron is a spherical regular octahedron or regular dodecahedron, and the included angle ⁇ is 45 to 80 degrees.
  • the spherical regular octahedron has eight spherical regular triangles and six vertexes 31
  • the spherical regular dodecahedron has twelve spherical regular pentagons and twenty vertexes 31 . Therefore, when each groove is formed about each vertex 31 and consequentially, six or twenty grooves are formed along the circular paths 39 such that they are connected to one another.
  • the area ratio of the grooves relative to the surface area of the golf ball may be too small to reduce an air resistance acting on the golf ball down to a desired level, or may be too large to improve the directionality of putting.
  • each groove can be changed into a variety of different shapes other than the above described shapes, so long as all the grooves maintain a net shape and fulfill the symmetry of a spherical surface, and the surface area of the grooves occupies 14 to 69% of the surface area of the golf ball.
  • the sphere 10 has a divisional composition of a spherical polyhedron, and grooves are formed along edges 41 of the spherical polyhedron.
  • the spherical polyhedron may be a spherical regular icosahedron, or may be a spherical icosahedron consisting of eight spherical regular pentagons and twelve spherical regular hexagons as shown in FIG. 6 .
  • the present invention is applicable in such a manner that grooves are formed along the edges 41 of the spherical polyhedron.
  • the grooves, formed along the edges 41 of the spherical polyhedron, may be connected to or separated from one another.
  • an experimental model of a golf ball was installed in a wind tunnel, to measure an air resistance acting on the experimental model while increasing the velocity of wind from 5 m/s to 30 m/s by 1 m/s.
  • the golf ball and the experimental model also have the same air resistance coefficient as each other. Accordingly, an air resistance actually acting on the golf ball could be calculated based on experimental values.
  • a regular hexahedron is inscribed in the model such that the model has a divisional composition of a spherical regular hexahedron.
  • a circular path 35 a is defined about one vertex 31 a of a spherical square constituting the spherical regular hexahedron by connecting three vertexes (only two vertexes 31 b and 31 c are visible from FIG. 8 ) closest to the vertex 31 a to one another.
  • the included angle ⁇ is approximately 70 degrees.
  • circular paths 35 b to 35 h thereof can be defined, and grooves can be formed along all the circular paths 35 a to 35 h .
  • grooves can be additionally formed along shorter diagonal lines 42 a , 42 b , 42 c , 42 d , . . . of some cells containing the edges 41 of the spherical regular hexahedron.
  • the diameter of the model was 150 mm.
  • the outer surface of the model was formed with grooves having a width of 5 mm and a depth of 0.5 mm.
  • protrusions having a height of 0.5 mm were additionally formed in the grooves.
  • the protrusions were partially cut and removed at intervals as shown in FIG. 9 .
  • Values in Table 1 represent reduced values of the models and should be considered as actual numerical values of the golf ball having grooves formed in the surface thereof on the basis of dimensional analysis and similarity.
  • FIG. 10 is a graph illustrating the relationship between the Reynolds number and the air resistance coefficient
  • FIG. 11 is a graph illustrating the relationship between the velocity of a golf ball and the air resistance.
  • an air resistance acting on the grooved golf ball begins to be smaller than that acting on the dimpled golf ball from the critical point where the Reynolds number is approximately 190,000 (the velocity of the golf ball is 240 km/hr). Since the initial velocity of a drive shot is 190 to 300 km/hr, the overall air resistance acting on the grooved golf ball is larger than that acting on the dimpled golf ball, thus suffering from a reduction of a carry distance and consequently, being unsuitable for use as a golf ball.
  • the air resistance acting on the grooved golf ball exceeds that acting on the dimpled golf ball, resulting in a reduced carry distance of the golf ball. Therefore, in this case, it is preferable that the number of the grooves, having the width of 2 mm or less, be increased as compared to that of Example 1, so as to increase the area ratio of the grooves relative to the surface area of the golf ball, for the sake of reducing the air resistance acting on the golf ball.
  • Example 2 in which protrusions are formed in the grooves, it is seen from FIGS. 10 and 11 that the air resistance acting on the grooved golf ball is smaller than that acting on the dimpled golf ball except for a region where the Reynolds number is 50,000(80 km/hr) to 110,000(140 km/hr).
  • the area ratio of the grooves relative to the surface area of the grooved golf ball is only approximately 23%. Therefore, the grooved golf ball of Example 2 could achieve a remarkable reduction in the occurrence of putting errors due to the curvature of the grooves, thus enabling accurate putting of the golf ball.
  • Example 3 has the same experimental conditions as those of Example 2 except for the fact that the protrusions formed in the grooves are partially cut and removed at intervals, rather than being continuously connected to one another. Similar to Example 2, the air resistance acting on the golf ball of Example 3 is smaller than that acting on the dimpled golf ball.
  • Example 4 the outer surface of the model is formed with grooves having a width of 10 mm and a depth of 1 mm.
  • Example 5 continuous protrusions having a height of 1 mm are formed in the grooves as shown in FIG. 12 .
  • Values in Table 2 represent reduced values of the models and should be considered as actual numerical values of the golf ball having grooves formed in the surface thereof on the basis of dimensional analysis and similarity.
  • FIG. 13 is a graph illustrating the relationship between the Reynolds number and the air resistance coefficient
  • FIG. 14 is a graph illustrating the relationship between the velocity of a golf ball and the air resistance.
  • Examples 4 and 5 show the air resistances acting on the grooved golf ball similar to that acting on the dimpled golf ball, it could be appreciated that the area ratios of grooves relative to the surface area of the respective golf balls of Examples 4 and 5 are only approximately 46%, thereby enabling accurate putting of the golf ball as compared to the dimpled golf ball.
  • the groove 20 When no protrusions are formed in the grooves, it is preferable that the groove 20 have a width W below 4 mm and a depth GH of 0.1 to 0.4 mm in consideration of the air resistance acting on the golf ball and the accurate directionality of putting. If the depth GH of the groove 20 is smaller than 0.1 mm, RPM of the backspin of the grooved golf ball decreases as compared to that of the dimpled golf ball, thus resulting in a reduced lift force.
  • the width W of the groove 20 is preferably 1 to 5 mm, and the depth GH of the groove 20 is preferably 0.1 to 0.5 mm. Also, in consideration of the accurate directionality of putting, the height H of the protrusion 21 is preferably smaller than the depth GH of the groove 20 . Similar to the grooves 20 , the protrusion 21 may be connected to or separated from other protrusions.
  • the width W and the depth GH of the groove 20 and the height H of the protrusion 21 , formed in the surface of the sphere 10 may be changed per their locations such that a variety of different sizes of grooves 20 or protrusions 21 exist together in the single sphere 10 .
  • a golf ball has net-shaped grooves formed throughout a sphere.
  • an air resistance acting on the golf ball is similar to or smaller than that acting on a dimpled golf ball, thus resulting in an improvement in the carry distance of the golf ball.
  • the present invention as a result of considerably reducing the area ratio of the grooves relative to the surface area of the golf ball, it is possible to reduce the occurrence of putting errors due to the curvature of the grooves, resulting in accurate putting of the golf ball.

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  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Physical Education & Sports Medicine (AREA)
  • Compositions Of Macromolecular Compounds (AREA)
  • Moulds For Moulding Plastics Or The Like (AREA)
US12/449,731 2007-02-22 2008-02-20 Golf ball Abandoned US20120270683A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
KR1020070017963A KR100803528B1 (ko) 2007-02-22 2007-02-22 골프공
KR10-2007-0017963 2007-02-22
PCT/KR2008/000985 WO2008102977A2 (en) 2007-02-22 2008-02-20 Golf ball

Publications (1)

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US20120270683A1 true US20120270683A1 (en) 2012-10-25

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US12/449,731 Abandoned US20120270683A1 (en) 2007-02-22 2008-02-20 Golf ball

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US (1) US20120270683A1 (de)
EP (1) EP2112948B1 (de)
KR (1) KR100803528B1 (de)
WO (1) WO2008102977A2 (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USD738972S1 (en) * 2014-06-02 2015-09-15 Wilson Sporting Goods Co. Practice ball
USD831135S1 (en) * 2015-12-31 2018-10-16 Eye On Ball, Inc. Sports ball

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3157248U (ja) 2009-06-09 2010-02-04 友彦 佐藤 楕円形ディンプルゴルフボール

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7033287B2 (en) * 2003-01-06 2006-04-25 Acushnet Company Golf ball with improved flight performance
US7455601B2 (en) * 2002-02-15 2008-11-25 Acushnet Company Golf ball with spherical polygonal dimples
US8033933B2 (en) * 2002-02-15 2011-10-11 Acushnet Company Golf ball surface patterns comprising variable width/depth multiple channels
US8137216B2 (en) * 2002-02-15 2012-03-20 Acushnet Company Golf ball surface patterns comprising multiple channels

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB191400645A (en) * 1914-01-09 1914-11-26 Avon India Rubber Company Ltd Improvements in or relating to Golf Balls.
GB189551A (en) * 1921-09-02 1922-12-04 Richard Thomson Glascodine Improvements in golf balls
GB297368A (en) * 1927-06-10 1928-09-10 George William Beldam An improved golf or similar game ball
JPS58131859U (ja) 1982-02-25 1983-09-06 高瀬　正夫 スピンゴルフボ−ル
JPS6131466U (ja) 1984-07-31 1986-02-25 殿村株式会社 競技用ボ−ル
JPS6292854U (de) 1985-12-02 1987-06-13
KR100187788B1 (ko) * 1996-10-01 1999-06-01 황춘근 골프공
US20040005937A1 (en) * 2001-07-02 2004-01-08 Saiz Manuel Munoz Golf ball
US6695720B2 (en) * 2002-05-29 2004-02-24 Acushnet Company Golf ball with varying land surfaces
EP1454660A1 (de) * 2003-03-07 2004-09-08 Manuel Munoz Saiz Ball mit Rillen

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7455601B2 (en) * 2002-02-15 2008-11-25 Acushnet Company Golf ball with spherical polygonal dimples
US8033933B2 (en) * 2002-02-15 2011-10-11 Acushnet Company Golf ball surface patterns comprising variable width/depth multiple channels
US8137216B2 (en) * 2002-02-15 2012-03-20 Acushnet Company Golf ball surface patterns comprising multiple channels
US7033287B2 (en) * 2003-01-06 2006-04-25 Acushnet Company Golf ball with improved flight performance

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USD738972S1 (en) * 2014-06-02 2015-09-15 Wilson Sporting Goods Co. Practice ball
USD831135S1 (en) * 2015-12-31 2018-10-16 Eye On Ball, Inc. Sports ball

Also Published As

Publication number Publication date
EP2112948A2 (de) 2009-11-04
KR100803528B1 (ko) 2008-02-14
EP2112948A4 (de) 2011-03-09
EP2112948B1 (de) 2013-09-04
WO2008102977A3 (en) 2008-12-31
WO2008102977A2 (en) 2008-08-28

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Owner name: SEOUL NATIONAL UNIVERSITY INDUSTRY FOUNDATION, KOR

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:CHOI, HAE CHEON;CHOI, JIN;SON, GWANG MIN;SIGNING DATES FROM 20090909 TO 20091001;REEL/FRAME:023488/0277

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION