Patent ID: 6136125
Filing Date: 2000-10-24
Classification: A63B,Y10T

Abstract:
A method of manufacturing a spherical body comprising: a core and at least one surface layer enclosing the core, the method comprising:preforming carried out in a two-part mold having two mold halves, each mold with half a hemispherical concave inner face defining a cavity, wherein a pair of sheet blanks each having opposed sides are placed over the cavities in the two halves of the mold such that one side of each blank faces the inner face of one mold half, then the opposite side of each blank is pressed while vacuum suction is applied to the one side facing the mold inner face through a large number of holes distributed uniformly on said inner face, for drawing each sheet blank up against the inner face of the respective mold half, thereby forming a pair of half-shells;surface layer forming carried out in another two-part mold having two mold halves, each of said mold halves of said another two-part mold having an inner face bearing pattern-forming projections, wherein the mold halves are separated, the pair of half-shells having inner and outer sides are loaded into the respective halves of the mold such that the outer side of each half-shell faces the inner face of the corresponding mold half, said core is placed on one of the mold halves, and the other mold half is joined thereto to close the mold, thereby pressing the core against the inner sides of the half-shells, concurrent with which vacuum suction is applied to the outer sides of the half-shells from the respective inner faces of the mold halves which have a large number of openings; andmolding in which the surface layer is fused and solidified onto the core within the closed mold.