Patent ID: 6997019
Filing Date: 2006-02-14
Classification: C03B

Abstract:
1. A molding process of a disk with a shaft shaped portion comprising the steps of: providing an upper die performing press molding from an upper surface, an intermediate die having a shaft forming hole portion for forming a shaft shaped portion and a lower die for forming a lower surface of said shaft shaped portion, said lower die being separate from said intermediate die, contact surfaces between said intermediate die and said lower die having a surface roughness that permits discharge of gas enclosed in said shaft forming hole portion through a gap between said intermediate die and said lower die; placing a glass material of revolving body shape having a circular cross-section in a direction perpendicular to its center axis and including a circular section at least greater than said shaft forming hole portion, on said shaft forming hole portion of said intermediate die; and subsequently performing press molding for said glass material.