Spiral-type magnetic recording and playback head drive device

Claim 1

A spiral-type magnetic recording and playback head drive device comprising: a rotary drive; a lower disk in driven contact with said drive; an upper disk having a slot therein and spaced from said lower disk and attached thereto, said upper disk adapted to have a recording sheet placed therein; a plate located between said upper and lower disks and associated with said lower disk for rotation therewith, said plate mounted for slidable movement with respect to said lower disk; a fixed element extending upwardly through a centrally located aperture in said lower disk and terminating between said upper and lower disks, said fixed element having a saucer-shaped flange formed at its upper end including an upwardly facing peripheral lip having spiral grooves formed thereon: a rack element mounted on said slidable plate and extending longitudinally between said upper and lower disks, said rack element having a toothed portion formed on a downwardly facing edge and being biased into engagement with said spiral grooves; a recording and playback head having mounting means located to be slidably movable with said slidable plate, said head positioned between said upper and lower disks and being vertically displaceable within a predetermined distance, said head being biased upwardly to partially extend through the slot in said upper disk to contact the recording sheet; and pivoted lever means mounted on said slidable plate and positioned to have one end of said lever means in contact with said rack element and the other end of said lever means in contact with said head-mounting means whereby vertical upward movement of said rack element overcomes the engaging bias and disengages said toothed portion and rotates said lever means to withdraW said head against the head bias downwardly from the slot out of engagement with the recording sheet.