Fine positioning apparatus for floppy disk drive

Apparatus for positioning a read/write head over a rotating disk of magnetic or other data storage media comprising:

• a first stepper motor means having a first rotor and a first stator;
• a first lead screw means driveably coupled to said first rotor for moving a read/write head moveably mounted on at least one rail disposed parallel to the longitudinal axis of said first lead screw means, said movement being inwardly and outwardly relative to the center of the disk in unitary steps of coarse increments;
• a second stepper motor means having a second rotor and a second stator;
• a second lead screw means coupled to said second rotor for causing movement of said read/write head in unitary steps of fine increment;
• first journalling means connected to said first lead screw means;
• a lead screw follower connected to said second lead screw means;
• means forming a pivot point located such that said first lead screw means is positioned between said second lead screw means and said pivot point;
• and
• an elongated lever arm having a first end portion engaging said second lead screw follower, an intermediate portion engaging said journalling means, and a second end portion bearing against said pivot point, whereby said read/write head is directly moved by actuation of said first stepper motor means as it rotates said first lead screw means and is indirectly moved by actuation of said second stepper motor means which through rotation of said second lead screw means causes pivoting movement of said lever arm about said pivot point which in turn causes incremental axial translation of said first lead screw means and consequent incremental movement of said read/write head.