Mechanism for actuating a protective shutter provided on a cartridge accommodating a disk

Claim 1

A mechanism for use in an information recording/reproducing apparatus, recording and/or reproducing an information signal on and from an information recording disk accommodated in a cartridge, for actuating a shutter of the cartridge so that a window defined in the cartridge is exposed responsive to an insertion of the cartridge into the apparatus and so that the window is covered responsive to the withdrawal of the cartridge from the apparatus, comprising: a base having a front side and a rear side, said base having formed therein a space extending from the front side to the rear side, said space being defined, in part, by a top wall extending between the front side and the rear side such that the space is formed underneath the top wall, said base being provided in a body of the information recording/reproducing apparatus for accepting the cartridge inserted to said space from the rear side of the base to the front side of the base when the cartridge is inserted into the apparatus; an arm held on the base so as to rotate freely in said space in a plane generally parallel to said top wall, said arm carrying a projection adapted to matingly cooperate with a depression formed at a front face of the shutter located at a front side of the cartridge which enters first into the space when the cartridge is inserted; and a coiled spring having a first end and a second end respectively secured on the base and the arm so as to urge the arm in a first direction opposing the rotation of the arm when the cartridge is inserted into said space and further in a second direction orthogonal to the first direction towards the top wall of the base such that the arm maintains a contact with said top wall which defines the space.