Magnetically coupled hard disk drive head positioner latch

Abstract

A fail-safe, magnetically coupled head positioner latch assembly for a Winchester-type disk drive comprises a rotatably mounted latch member including an outwardly extending latch arm and tang, and a solenoid assembly. The latch arm is adapted for engaging the head positioner in a parked position, and rotating to a non-interactive position with the latch arm being non-interactive with the head positioner. Magnetic coupling force between a permanent magnet structure and the solenoid assembly causes the latch arm to remain in the non-interactive position during normal disk drive operation. Activation of the latch is accomplished by applying current to the solenoid which generates a magnetic field opposite to that of the permanent magnet structure causing the rotatably mounted latch assembly to rotate so that the latch arm engages the head positioner. The tang is adapted for interacting with a permanent magnet structure as the latch arm engages the head positioner, whereby the magnetic coupling force between the tang and the permanent magnet structure imparts a torquing force to the latch arm which restrains the head positioner in the parked position. Actuation of the head positioner upon initiating normal disk drive activity positively disengages the head positioner from the parked position.