Pivoting, dual state magnetic latch for disk file actuator

Abstract

A toggling, dual state magnetic latch is provided for a disk file rotary head positioner rotatably mounted relative to the base and includes a voice coil for rotary displacement within a magnetic field provided by an actuator voice coil permanent magnet. The latch comprises a latch pin formed of a ferromagnetic material located on an arm extending from the voice coil of the actuator; a latch mounting pivot pin mounted to the base, a latch body rotatably mounted to the latch mounting pivot pin and positionable between an unlatched position and a latched position, the latch body including a toggle portion carrying a latch permanent magnet and including a counterweight portion located generally oppositely of the toggle portion for carrying counterweight for counterweighting the latch body about an axis of rotation aligned with the latch mounting pivot pin, a bias force mechanism including the voice coil permanent magnet for applying a predetermined bias force to the latch body in order to maintain it at the unlatched position, the latch body and the latch pin being so located that as the latch pin moves in a direction toward the latch body and reaches a predetermined distance to the latch permanent magnet, the bias force is rapidly overcome, and the latch body toggles to a latched position such that the latch pin is directly adjacent to the latch permanent magnet when the actuator has positioned the data transducer head at a landing zone on the storage disk.