Shutter assembly for use in a disc cartridge

Claim 1

A disc cartridge comprising: a cartridge case comprising a first half case and a second half case, a drive shaft insertion opening defined in a central portion of said cartridge case, a shallow recess defined in a front portion of each half case, corresponding head accessing openings defined in each of said shallow recesses and a guide slot provided on at least one of said first half case and said second half case near a front edge of said cartridge case extending parallel to said front edge of said cartridge case, a magnetic disc rotatably mounted in said cartridge case; and a shutter slidably mounted on said cartridge case for opening and closing said head accessing openings, movable along said respective guide slot, said shutter being formed in a general U character shape comprising first and second parallel flat plates joined by a connecting plate, said shutter presenting an open end for insertion of said shutter on said cartridge case, each of said first and second flat plates being provided with openings which coincide with said head accessing openings during opening of the shutter, said shutter being provided with at least one projection provided on at least one of said first and second flat plates closely positioned to said connecting plate extending angularly inward relative to the other of said respective plates, said at least one projection including an elongated portion terminating at a free end, said elongated portion extending at an obtuse angle from said flat plate toward said connecting plate, said projection being made of a resin material which allows said projection to temporarily deform as the shutter is mounted on said cartridge case and to spring back to be captured in one of said guide slots.