Disk brake mechanism for a disk cartridge

In a cartridge comprising opposed first and second spaced-apart plates defining an internal compartment in which a rotatable information recording disk is disposed, the improvement comprising:

• (a) a peripheral wall, joining said spaced-apart plates, having an aperture in a forwardly facing portion thereof communicating with a corner of said internal compartment;
• (b) a unitary generally V-shaped brake member mounted in said corner of said compartment on a pivot, disposed at the vertex of the V and connected to one of said first and second plates, for pivotal movement between a disk-braking position and a disk-releasing position, one leg of said V-shaped brake member extending toward said forwardly facing peripheral wall and terminating in an exposed position adjacent to and in alignment with the aforementioned aperture of said peripheral wall and a second leg of said V-shaped brake member terminating in a nook-like nose portion adjacent to and facing a circumferential edge of the disk;
• (c) a pair of stationary V-shaped nooks each of which is defined by first and second ramp-like mating portions integral, respectively, with said first and second plates, said pair of nooks being angularly spaced apart from one another facing a circumferential edge of the disk generally diametrically opposed to the circumferential edge of the disk adjacent said nook-like nose portion of said brake member;
• and
• (d) a U-shaped spring mounted to receive the vertex of said brake member with one arm of said spring pressed against a side peripheral wall of said cartridge and the other arm of said spring seated in a slot of said brake member, said spring being arranged to produce a bias force normally pivoting said brake member into its disk-braking position wherein said nook-like nose portion is caused to engage the adjacent circumerential edge of the disk and to thereby urge the opposite circumferential edge of the disk into engagement with said stationary nooks for immovably holding the disk within said cartridge, said spring producing a bias force of a magnitude that is overcome by direct engagement, through the aperture of said forwardly facing peripheral wall, of said first leg of said brake member with a disk drive mechanism when said cartridge is operatively loaded into such drive mechanism, whereby operative loading movement of said cartridge causes the drive mechanism to move said brake member, against the bias force of said spring, from its disk-braking position to its disk releasing position.