Means for holding stamper plate in molding metal die

Abstract

In a means for holding a stamper plate in a molding metal die so that the stamper plate can be easily mounted on and dismounted from the surface of a disc cavity plate, the means comprises the stamper plate having a hole at the center thereof and composed of a ferromagnetic substance, a stamper plate bush having an engaging shaft portion to be engaged with the center hole of the stamper plate in a molding cavity and disposed at the center of the disc cavity plate on the side where the stamper plate is mounted, a magnetic flux generating means disposed in a ring shape around the outer periphery of the engaging shaft portion of the stamper plate bush in the disc cavity plate for generating magnetic flux in a direction vertical to the surface of the stamper plate coupled with the engaging shaft portion, a vacuum hole defined to the disc cavity plate in correspondence to the portion of the stamper plate where no information is recorded for vacuuming the rear surface of the stamper plate, and an air passage defined to the disc cavity plate for connecting the vacuum hole to a vacuum means. The stamper plate is supported on the disc cavity plate by a magnetic force and a vacuuming force.

Dependencies are inferred from the claim text.