Magnetic disc cartridge

摘要

A magnetic disc cartridge includes a larger capacity magnetic disc with a center core fixed to its center. The magnetic disc is contained for rotation in a casing which is provided with a spindle hole through which a spindle of the disc drive system is inserted into the casing. The center core is provided with a collar portion on which the magnetic disc is fixed and an abutment surface which is parallel to the collar portion and is adapted to be held against a pedestal surface on the spindle of the disc drive system under magnetic attraction. A center hole is formed in the abutment surface substantially at the center thereof and a drive pin hole is formed in the abutment surface radially outwardly spaced from the center hole. An annular protrusion is formed on the inner surface of the casing so as to project toward the center core inside the collar portion to limit radial movement of the center core. A contact member is formed around the annular protrusion to project toward the center core so that the contact member is held away from the collar portion when the center core is rotated with the magnetic disc held horizontally and is brought into contact with the collar portion when the center core is rotated with the magnetic disc held inclined. <IMAGE>