NZ237233A

NZ237233A - Golf ball having non-circular dimples of isodiametrical shape when viewed

Info

Publication number: NZ237233A
Application number: NZ237233A
Authority: NZ
Inventors: Brian Francis Machin
Original assignee: Dunlop Ltd
Priority date: 1990-03-27
Filing date: 1991-02-27
Publication date: 1993-12-23
Also published as: FR2661101A1; FR2661101B1; JPH04221578A; AU651331B2; AU7114091A; GB2242363B; ZA912223B; GB9006761D0; MY104810A; GB2242363A

Description

Henry Hughes Ltd 237 2 3 'Patents "Form 5 c;--: flv&gKlW.

Pu-:,;,; Ds:d; . 2,3.DEC 1993 ^" r,C. Jou.-,?:, ivo: .. J30S".

N.Z. PATENT OFFICE 27 FEB1991 RECEIVE N.Z. No.

MEW ZEALAND Patents Act 1953 COMPLETE SPECIFICATION GOLF BALLS WITH ISODIAMETRICAL DIMPLES We, DUNLOP LIMITED, a British Company of Silvertown House, Vincent Square, London SW1P 2PL, England, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement - 1 - (Followed by 1A) 23 7233 1A GOLF BALLS WITH ISODIAMETRICAL DIMPLES This invention relates to golf balls with isodiametrical dimples.

It has been known for many ''years to provide a golf ball with a plurality of dimples in order to optimise the aerodynamic properties of trie ball. Such dimples are generally circular in plan view although others have been used including triangular, rectangular, pentagonal and hexagonal shapes.

The rules laid down by the governing bodies of the game require that golf balls should behave relatively uniformly from an aerodynamic point of view while the requirements of the golfer also place great emphasis on increased distance to be achieved by reducing the drag force on the ball during flight.

Golf ball dimple patterns are of the most profound importance in meeting these requirements both in terms of dimple shape and dimple pattern arrangement.

The use of circular dimples imposes undesirable constraints on surface coverage and on maintaining the optimum relationship between adjacent dimples for reducing the drag force acting on the ball to a minimum but constant diameter is also a desirable feature in creating uniformity in aerodynamic behaviour.

It has now been found that dimples which are non-circular but isodiametrical in plan view can not only provide far greater efficiency of surface coverage but also result in improved aerodynamic properties. Accordingly,■ the present invention provides a golf ball having in its spherical surface a plurality of dimples, in which each dimple has the shape, when viewed from above, of a regular isodiametrical figure with an odd number of sides and arcuate apices.

The isodiametrical figures may have up to thirteen sides and may be selected from regular isodiametrical figures having three, five, seven, nine, eleven and thirteen sides.

Preferably, the dimples are arranged on the<^ £ NOV 1993 n / 2. spherical surface of the ball in a uniform repeating pattern.

The pattern may conveniently be defined by projecting on to the spherical surface of the ball the edges of a regular polyhedron.

Examples of regular polyhedra for the dimple pattern include the cube, the octahedron, the dodecahedron/ the icosahedron and the icosi-dodecahedron.

The present invention will be illustrated, merely by way of example, in the following description and with reference to the accompanying drawings.

In the drawings: Figure 1 is a schematic view of a golf ball having three-sided isodiametrical dimples, the dimples being arranged in a regular dodecahedral pattern? Figure 2 is a schematic view of a golf ball having five-sided isodiametrical dimples, the dimples being arranged in a regular icosahedral pattern; Figure 3 is a schematic view of a golf ball having five-sided isodiametrical dimples/ the dimples being arranged in a regular dodecahedral pattern.

In Figure 1, a golf ball 10 is provided with a plurality of dimples 11. Each dimple has the shape of an equilateral three-sided isodiametrical figure with arcuate, apices. The dimple pattern is indicated by broken lines 12 to 23 inclusive, representing the projection on the spherical surface of the ball of the edges of a regular dodecahedron.

In Figure 2, a golf ball 30 is provided with a plurality of dimples 31. Each dimple has the shape of a regular five-sided isodiametrical figure with arcuate apices and the dimple pattern is indicated by broken lines 32 to 41 inclusive, representing the projection on to the_ spherical surface of the ball | N.Z. PATENT OI-FICE 21 OCT IS93 L 237233 3. of the edges of a regular icosahedron.

In Figure 3, a golf ball 50 is provided with a plurality of dimples 51. Each dimple has the shape of a regular five-sided isodiametrical figure with arcuate apices and the dimple pattern is indicated by broken lines 52 to 61 inclusive, representing the projection <m±o the spherical surface of the ball of the edges of a regular dodecahedron. more than one size may be employed' in the dimple pattern.

As can be seen in the drawings, dimples of 237233 4.

Claims

WHAT WE CLAIM IS:

1. A golf ball having in its spherical surface a plurality of dimples, in which each dimple has the shape, when viewed from above, of a regular isodiametrical figure with an odd number of sides and arcuate apices.

2. A golf ball according to Claim 1, in which the said dimples comprise those whose regular isodiametrical figure is a three-sided figure.

3. A gcjlf ball according to Claim 1 in which the said dimples comprise those whose regular isodiametrical figure is a five-sided figure.

4. A golf ball according to claiM | in which the said dimples comprise those whose regular isodiametrical figure is a seven-sided figure.

5. A golf ball according to claim 1 , in which the said dimples comprise those whose regular isodiametrical figure is a nine-sided figure.

6. A golf ball according to claiw^ | ■L in which the said dimples comprise those whose regular isodiametrical figure is an eleven-sided figure.

7. A golf ball according to claim I in which the said dimples comprise those whose regular isodiametrical figure is a thirteen-sided figure.

8. A golf ball according to any one of the preceding Claims, in which the said dimples are of more than one size.

9 A golf ball according to any one of the preceding Claims, in which the dimples are arranged on the spherical surface of the ball in a uniform repeating pattern. _

10. A golf ball according to Claim 9, in which N ^ the uniform repeating pattern is defined by projecting * on to the spherical surface of the ball the edges of.; \y- 5 NOV 1993 5. a regular polyhedron.

11. A golf ball according to Claim 10, in which the polyhedron is a cube.

12. A golf ball according to Claim 10, in which the polyhedron is a regular octahedron.

13. A golf ball according to Claim 10, in' which the polyhedron is a regular dodecahedron.

14. A golf ball according to Claim 10, in which the polyhedron is a regular icosahedron.

15. A golf ball according to - Claim 10, in which the polyhedron is a regular icosi-dodecahedron.

16. A golf ball, substantially as hereinbefore described, with reference to and as illustrated in the accompanying drawings. DUNLOP LIMITED By their attorneys HENRY HUGHES LTD/ // ^ ' ii\} o 5 NOV