Process for making multi-layer core golf balls

• US 6,290,797 B1
• Filed: 04/02/1999
• Issued: 09/18/2001
• Est. Priority Date: 04/02/1999
• Status: Expired due to Term

• Current Assignee: Acushnet Company (FILA Holdings Corp.)
• Original Assignee: Acushnet Company (FILA Holdings Corp.)
• Inventors: Goguen, Douglas, Gosetti, Steven M.
• Primary Examiner(s): Knable, Geoffrey L.
• Application Number:
  US09/283,965
• Time in Patent Office: 900 Days
• Field of Search: 156/146, 156/228, 156/245, 156/288, 156/292, 156/233, 156/303.1, 156/273.3, 156/273.5, 156/311, 473/371, 473/374, 264/271.1, 264/279.1, 264/248, 264/250, 264/255, 264/266-268, 264/322, 264/325, 264/327
• US Class Current: 156/228
• CPC Class Codes: A63B 37/0003 Golf balls
• CPC Class Codes: A63B 37/0039 characterised by the material
• CPC Class Codes: A63B 37/0045 Thickness
• CPC Class Codes: A63B 37/0052 Liquid cores
• CPC Class Codes: A63B 37/0075 Three piece balls, i.e. cover, intermediate layer and core
• CPC Class Codes: A63B 37/0076 Multi-piece balls, i.e. having two or more intermediate layers
• CPC Class Codes: A63B 37/04 Rigid cores
• 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 69/004 making articles by joining parts moulded in separate cavities, said parts being in said separate cavities during said joining B29C45/006, B29C51/267 take precedence
• CPC Class Codes: B29L 2031/54 Balls
• CPC Class Codes: B29L 2031/546 Golf balls

Abstract

The invention provides a process for manufacturing a golf ball, particularly a multi-layer golf ball. The process comprises forming a pre-molded center, molding two substantially hemispherical shells having substantially hemi spherical cavities, shaping the shells in a press having a top mold and a bottom mold, each with cavities concaving toward each other and a center plate having top and bottom protrusions. The shells are placed in the cavities of the bottom mold and the protrusions of the center plate. The three parts of the press are aligned and closed as the press is heated to a temperature below the cure activation temperature of the shell material. The center plate is then removed from the press with the shells in the cavities of the top and bottom mold. as ball center is inserted between the shells and the press is again closed and heated to a second temperature, above the cure activation temperature, fusing the shells around the center and forming a golf ball core. A cover is thereafter formed over the core either through compression or injection molding.

Claims

1. A method for manufacturing a golf ball comprising:

a) forming a pre-molded center;

b) providing a press with a top mold, a slidable center plate, and a bottom mold;

c) placing pre-moldcd hemispherical shells into the bottom mold and on top of the center plate;

d) sliding the center plate between the top and bottom molds;

e) closing the press with the top and bottom molds and the center plate that are in substantial alignment with respect to each other;

f) hcating the press to a first temperature below the shells'"'"' crosslinking temperature such that the shells are pliable and form substantially hemispherical cups;

g) retaining the hemispherical cups within the hemispherical cavities of the top and bottom molds by cooling the top and bottom molds while allowing the center plate to remain at a higher temperature than the temperature of the top and bottom molds after said cooling, opening the press, and removing the center plate;

h) placing the pre-molded center within the henispherical cups;

i) closing the press with the top and bottom molds to join the hemispherical cups around the pre-molded center to form a golf ball core; and

j) forming a cover over the golf ball core.

2. The method of claim 1, wherein the step of closing the press with the top and bottom molds to join the hemispherical cups around the pre-molded center to form a golf ball core further comprises heating the molds to cause crosslinking between the cups and thereafter cooling the molds to cause thermal contraction of the cups.

3. The method of claim 1, wherein the step of providing a press further comprises providing flow channels in the top and bottom molds and the center plate for cooling or heating the top and bottom molds and the center plate.

4. The method of claim 1, wherein the step of closing the press with the top and bottom molds to join the hemispherical cups around the pre-molded center to form a golf ball core further comprises adhesively attaching the cups to each other.

5. A method of making a golf ball, comprising:

a) forming a pre-molded center;

b) providing a bottom mold having a plurality of cavities, a top mold having a plurality of corresponding cavities and a center plate having a plurality of corresponding top and bottom protrusions;

c) forming a plurality of substantially hemispherical cups from elastomeric material by;

i) placing elastomeric material in the cavities of the bottom mold and on the top protrusions of the center plate;

ii) lociting the center plate between the top and bottom molds; and

iii) compressing the elastomeric materials to form hemispherical cups in the bottom and top mold frame cavities;

d) removing the center plate from between the top and bottom molds;

e) placing the pre-molded centers in the hemispherical cups in the bottom mold;

f) locating the top mold over the bottom mold;

g) joining the hemispherical cups around the pre-molded centers to form a substantially spherical core; and

h) molding a cover around the core.

6. The method of claim 5, wherein the step of closing the press further comprises elevating the temperature of the elastomeric material to a second temperature above the cure activation temperature.

7. The method of claim 6, wherein the step of joining the hemispherical cups further comprises cooling the elastomeric material to induce thermal contraction of the elastomeric material to facilitate removal from the molds.

8. A method of claim 7, wherein the step providing a press further comprises providing flow channels in the top and bottom molds and the center plate.