Shutter mechanism for a portable data storage cartridge

This invention relates to portable data storage cartridges, and, more particularly, to openable and closable covers for access openings in such portable data storage cartridges. A shutter mechanism is provided at an access opening in a portable data storage cartridge. Clamshell shutters meet at a common junction in the access opening. Actuation paddles positioned at the clamshell shutters are arranged to, when engaged by actuation pins, pivot the respective clamshell shutters in opposite directions away from the common junction, to expose the access opening. The clamshell shutters are mounted such that, when pivoted away from the common junction, each clamshell shutter remains within the cartridge housing.