Method and apparatus for demolding a golf ball
An apparatus and method for demolding golf balls from a mold cavity are disclosed. More specifically, an apparatus and method for demolding a golf ball from a mold cavity subsequent to forming a cover layer without the use of ejector or knockout pins are disclosed. The molding apparatus utilizes an undercut configuration that, upon opening the molds after molding a golf ball, serves to impart a rotational force upon the ball and dislodge it from the molds.
1. A molding assembly for demolding a golf ball comprising:
a first mold member defining a first non-planar engagement face and a first generally hemispherical molding surface; and
a second mold member defining a second non-planar engagement face and a second generally hemispherical molding surface;
wherein upon engagement by the molding members along the first and second engagement faces, the first and second molding surfaces define a molding chamber sized to accommodate a golf ball core or golf ball intermediate assembly, each of the molding members having a maximum undercut angle defined as the angle extending between an undercut mold edge and a plane that intersects a center of the molding assembly and which is parallel to a parting line that defines the mold undercut edge, the maximum undercut angle being from about 1° to about 35°.
2. The molding assembly of claim 1 wherein the maximum undercut angle is in the range of from about 5° to about 30°.
3. The molding assembly of claim 2 wherein the maximum undercut angle is in the range of from about 10° to about 25°.
4. The molding assembly of claim 3 wherein the maximum undercut angle is in the range of from about 15° to about 20°.
5. The molding assembly of claim 1 wherein each of the first and second mold halves are free of ejector pins.
6. A process for producing a ball, the process comprising:
providing a molding assembly including (i) a first mold member defining a first engagement face and a first generally hemispherical molding surface, and (ii) a second mold member defining a second engagement face and a second generally hemispherical molding surface, the molding assembly defining a maximum undercut angle greater than 1°, wherein the maximum undercut angle is defined as the angle extending between an undercut mold edge and a plane that intersects a center of the molding assembly and which is parallel to a parting line that defines the mold undercut edge;
disposing a ball core or intermediate ball assembly into at least one of the first and second molding surfaces;
engaging the first mold member and the second mold member together to thereby enclose the ball core or intermediate assembly within a closed molding chamber;
introducing a flowable molding material into the closed molding chamber and about the ball core or intermediate assembly;
at least partially solidifying the molding material about the ball core or intermediate assembly, to thereby form a finished ball; and
separating the first mold and the second mold to thereby displace the finished ball from at least one of the first mold and the second mold, wherein displacement of the finished ball occurs without the use of an ejector pin.