Abstract: A cleaning device for the heads of a Personal Computer is in the form of a diskette insertable in a disk drive of the computer. The diskette is provided with a pair of superimposed abrasive disks each of which rubs against one head of the computer when the diskette is in the disk drive and the latter is activated.

Abstract: A computer diskette burnishing machine that consists of two burnishing units adapted to operate on the magnetic medium of a conventional computer disk through the upper and lower read/write head access windows in the disk's protective shell. The assembled diskette is positioned on a lower burnishing unit that comprises a supporting plate having the same mechanical characteristics of a corresponding computer disk drive, including an electric motor equipped with a spindle/hub interface and shell registration pins. While the disk rotates, the burnishing units polish the disk's upper and lower surfaces by means of upper and lower abrasive tapes fed by a system of supply and take-up reels. The lower burnishing unit includes a resilient roller backing up the lower abrasive tape and disposed radially with respect to the plane of the disk. The upper burnishing unit consists of a spring-loaded resilient roller backing up the upper abrasive tape and disposed radially in parallel to the lower roller.

Abstract: A disk assembly which is normally fixed on a disk drive, but which can be removed in the field from the disk drive spindle and replaced on the spindle with extreme precision so that pre-recorded tracks are concentric with the axis of the spindle within extremely small tolerances. The disk assembly includes a mounting ring which fits around the drive spindle, the ring having three resilient centering flexures extending slightly radially inwardly of the rest of the ring to engage the drive spindle, and all being outwardly deflected substantially the same amount to center the ring on the spindle.