Magnetic head locking mechanism

Abstract

The present invention provides a magnet positioned to attract and hold a portion of a head arm in a disk drive assembly. The magnet is mounted by a resilient mechanism to a support structure so that there is some overtravel when the head arm assembly contacts the magnet, to dampen the impact and prevent the head arm from bouncing away and maintain contact when the disk drive housing receives an external shock. The present invention is preferably implemented with a swing plate which extends downward from the head arm support structure and is mounted at the top portion by a spring-loaded screw. A magnet is mounted on the bottom portion of the swing plate, and interacts with a permeable iron lock pin coupled to the voice coil of the head arm assembly. A pair of locating pins extend through holes in the mid-portion of the swing plate to guide the movement of the swing plate. The swing plate is levered about a short intermediate plate between it and the support structure which extends approximately one-third of the length of the swing plate. The length of this intermediate plate is chosen to give an optimum compromise between the amount of overtravel in the swing plate and the holding force of the swing plate and magnet arrangement. By bending the swing plate, its maget is moved farther from the read/write area of the disk and improved damping is provided, allowing relaxed tolerances.