Mold and method of molding golf ball having dimples on the equator

• US 20040138009A1
• Filed: 01/10/2003
• Published: 07/15/2004
• Est. Priority Date: 01/10/2003
• Status: Active Grant

• Current Assignee: Acushnet Company (FILA Holdings Corp.)
• Original Assignee: Acushnet Company (FILA Holdings Corp.)
• Inventors: Sullivan, Michael J.
• Granted Patent: US 6,893,362 B2
• Time in Patent Office: Days
• US Class Current: 473/378
• CPC Class Codes: A63B 37/0004 Surface depressions or protrusions
• CPC Class Codes: A63B 37/00065 located around the pole or the equator
• CPC Class Codes: A63B 37/0021 Occupation ratio, i.e. percentage surface occupied by dimples
• CPC Class Codes: A63B 45/00 Apparatus or methods for manufacturing balls working of plastics or substances in a plastic state B29
• CPC Class Codes: B29C 33/301 Modular mould systems [MMS], i.e. moulds built up by stacking mould elements, e.g. plates, blocks, rods B29C33/0088 takes precedence
• CPC Class Codes: B29D 99/0042 Producing plain balls hollow balls B29D22/04
• CPC Class Codes: B29L 2031/52 Sports equipment ; Games; Articles for amusement; Toys B29L2031/54 takes precedence
• CPC Class Codes: B29L 2031/54 Balls

Abstract

A method and mold for making a multi-parting line golf ball by compressing a dimple arrangement about a pre-formed sphere. The mold comprises at least three mold inserts having dimple producing projections on their inner spherical surfaces. Upon the dimples being molded to the pre-formed sphere, the resulting parting lines which are offset to the equator of the sphere, are visually inconspicuous, due to the pre-formed sphere being of a net size and weight very similar to the finished golf ball. The method of the invention allows for dimples to be located at and on the equator of the ball.

Claims

1. A golf ball mold for applying a dimple arrangement to a pre-molded sphere, the mold comprising:

at least three inserts in contiguous engagement with each other and removably mated along multiple parting lines;

each insert having a spherical cavity surface to define a spherical cavity for receiving the pre-molded sphere;

a plurality of dimple forming projections defined in the spherical cavity surfaces of the inserts; and

the pre-molded sphere of a net size and weight similar to the finished golf ball.

2. The golf ball mold according to claim 1, wherein the pre-molded sphere is of a thermoplastic material.

3. The golf ball mold according to claim 1, wherein the pre-molded sphere is a partially cured thermoset material that is fully cured during the dimple molding of the ball.

4. The golf ball mold according to claim 1, wherein the golf ball has an equator and the mold imparts parting lines that are offset to the equator of the ball.

5. The golf ball mold according to claim 4, wherein the parting lines are relatively negligible.

6. The golf ball mold according to claim 4, wherein dimples are molded on the equator of the ball.

7. The golf ball mold according to claim 1, wherein the mold comprises three inserts forming parallel parting lines on the golf ball.

8. The golf ball mold according to claim 7, wherein the dual parting lines include:

an upper parting line and a lower parting line;

the upper parting line being spaced from a first pole by a first distance; and

the lower parting line being spaced from an opposite pole by a second distance which is less than the first distance.

9. The golf ball mold according to claim 8, wherein the first distance is between about 30 to 49 percent of the diameter of the pre-molded sphere.

10. The golf ball mold according to claim 8, wherein the second distance is between about 3 to 20 percent of the diameter of the pre-molded sphere.

11. The golf ball mold according to claim 1, wherein the mold comprises four inserts forming four parting lines on the golf ball.

12. The golf ball mold according to claim 11, wherein two of the parting lines are continuous and two of the parting lines are partial.

13. The golf ball mold according to claim 12, wherein the partial parting lines are on an equator.

14. A method of molding a golf ball having multiple parting lines, the method comprising the steps of:

(a) providing a plurality of mold inserts, each insert having a spherical cavity surface for defining a spherical cavity having a plurality of dimple forming projections therein;

(b) providing pre-molded spheres of a net size and weight of the golf ball;

(c) loading the pre-molded spheres into the spherical cavity;

(d) forming a cover with a plurality of dimples; and

(e) imparting multiple parting lines.

15. The method according to claim 14, wherein the parting lines comprise dual parting lines, the lines comprising of:

an upper parting line and a lower parting line;

the upper parting line being spaced from a first pole by a first distance; and

the lower parting line being spaced from an opposite pole by a second distance which is less than the first distance.

16. The method according to claim 15, wherein the first distance is between about 30 to 49 percent of the diameter of the pre-molded sphere.

17. The method according to claim 15, wherein the second distance is between about 3 to 20 percent of the diameter of the pre-molded sphere.

18. The method according to claim 14, wherein the golf ball has an equator and dimples are located on the equator.

19. The method according to claim 14, wherein the parting lines comprise four parting lines, the lines comprising of:

a top parting line, a bottom parting line, and a pair of vertical parting lines extending between the top and bottom lines.

20. The golf ball mold according to claim 19, wherein two of the parting lines are continuous and two of the parting lines are partial.

21. The golf ball mold according to claim 20, wherein the partial parting lines are on an equator.

22. The golf ball mold according to claim 14, wherein the parting lines are relatively negligible.

23. A golf ball manufactured by compressing dimples in an arrangement about a pre-molded sphere, the ball comprising:

the pre-molded sphere of a net weight and size similar to the ball, the sphere having an equator;

a plurality of visually inconspicuous parting lines offset from the equator; and

dimples located on the equator.

24. The golf ball according to claim 23, wherein the parting lines comprise dual parting lines, the lines comprising of:

an upper parting line and a lower parting line;

the upper parting line being spaced from a first pole by a first distance; and

the lower parting line being spaced from an opposite pole by a second distance which is less than the first distance.

25. The golf ball according to claim 24, wherein the first distance is between about 30 to 49 percent of the diameter of the pre-molded sphere.

26. The golf ball according to claim 24, wherein the second distance is between about 3 to 20 percent of the diameter of the pre-molded sphere.

27. The golf ball according to claim 23, wherein the parting lines comprise four parting lines, a top parting line, a bottom parting line and a pair of vertical parting lines, each vertical parting line extending between the top and bottom parting lines.

28. The golf ball mold according to claim 27, wherein two of the parting lines are continuous and two of the parting lines are partial.

29. The golf ball mold according to claim 28, wherein the partial parting lines are on an equator.

30. The golf ball mold according to claim 23, wherein the parting lines are relatively negligible.